Wastewater reuse zamsif report_12122004_updated

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  • 1. USE OF WASTEWATER FOR IRRIGATION IN VEGETABLE GROWING IN THE KAFUE LAGOON AREAS AND ALONG NGWERERE RIVER Report PMA 24 (Final Report) By Charles Bwalya Chisanga, Water and Sanitation Association of Zambia Oscar Musweu Silembo, Department of Water Affairs, Ministry of Energy and Water DevelopmentFinanced by the Zambia Social investment Fund of the Ministry of Finance and National Planning November 2004 i
  • 2. DISCLAIMERThe views expressed in this report are those of the researchers and not the Zambia SocialInvestment Fund (Zamsif) as a funding agency. Any errors or omissions are the responsibilitiesof the researchers. ii
  • 3. TABLE OF CONTENTSAcknowledgement ivList of Tables vList of Figures viiList of Plates viiiAbbreviations and Acronyms xExecutive Summary x CHAPTER 1 INTRODUCTION ....................................................................................................1 1.1 Background................................................................................................................1 1.2 Objectives ..................................................................................................................2 1.3 Justification ................................................................................................................2 1.4 Significance of the Parameters.................................................................................3 CHAPTER 2: LITERATURE REVIEW ........................................................................................4 2.1 General ......................................................................................................................4 2.7 Treatment of Wastewater..........................................................................................4 2.3 Quantity of Wastewater Produced ............................................................................6 2.4 Toxicological Aspects of Wastewater.......................................................................6 2.5 Costs and benefits of Using Wastewater .................................................................7 2.6 Agronomic Aspects....................................................................................................8 2.7 Environmental Evaluation of Wastewater.................................................................9 2.8 Public Health Aspects ...............................................................................................9 2.9 Environmental Aspects............................................................................................11 2.10 Sociocultural Aspects ..............................................................................................11 2.11 Irrigation Methods....................................................................................................13 2.12 Policy Aspects..........................................................................................................13 CHAPTER 3: DESCRIPTION OF THE STUDY AREAS..........................................................14 3.1 Kafue Lagoon...........................................................................................................14 3.1.1 Site 1 (Shikoswe Stream) ...................................................................................15 3.1.2 Site 2 (Near Lee Yeast, LY)................................................................................15 3.1.3 Site 3 (Nitrogen Chemicals of Zambia, NCZ) ....................................................15 3.2 Ngwerere River Area...............................................................................................17 3.2.1 Site 1 (Near Garden Site 3 ponds, N1) ..............................................................18 3.2.2 Site 2 (At Ngwerere Estate Weir, N2) ................................................................18 3.2.3 Site 3 (Below Kasisi Dam, N3) ...........................................................................18 CHAPTER 4: METHODOLOGY ................................................................................................20 iii
  • 4. 4.1 Secondary Data collection ......................................................................................204.2 Primary Data Collection...........................................................................................204.2.1 Field Interviews ...................................................................................................204.2.2 Computation of the Quantity of Wastewater......................................................214.2.3 Plant sampling.....................................................................................................214.3.4 Sampling of Water, Sediments and Plants ........................................................214.4 Measurements of the Parameters ..........................................................................234.4.1 Laboratory Analysis ............................................................................................234.4 Data Analysis ...........................................................................................................234.5 Limitation of the study .............................................................................................24CHAPTER 5: RESULTS AND DISCUSSION ...........................................................................265.0 Field interviews ........................................................................................................265.1.1 Demographic information on households using the wastewater ......................265.1.2 Kafue Lagoon Area .............................................................................................265.1.3 Ngwerere River Area ..........................................................................................265.1.4 Agricultural Practice ............................................................................................275.1.5 Crop choice .........................................................................................................275.1.6 Water Management and Sources ......................................................................295.1.7 Conveyance of water and field application ........................................................305.1.8 Crop yields and earnings from their sells...........................................................315.1.9 Crop marketing by farmers in the Ngwerere and Kafue Lagoon areas............315.1.10 Crop marketing by the farmers in the Ngwerere Area.......................................315.1.11 Crop marketing by farmers in the Kafue Lagoon area ......................................325.1.12 Earnings from sales of crops in Kafue Lagoon Areas......................................335.1.13 Earnings from sales of crops in Ngwerere River Area ......................................345.1.14 Public health issues ............................................................................................345.1.15 Constraints faced by farmers in Kafue Lagoon and the Ngwerere areas ........365.2 Quantity of wastewater in the Ngwerere river .......................................................365.3 Plant sample analysis..............................................................................................395.4 Water quality analysis .............................................................................................405.4.1 Physico-chemical results ....................................................................................405.4.2 Microbiological Results .......................................................................................505.5 Sediment analysis from the Ngwerere river and Kafue lagoon Area ....................52CHAPTER 6: CONCLUSION AND RECOMMENDATIONS.....................................................546.1 Introduction ..............................................................................................................546.2 Achievement of specific objectives of the study.....................................................576.3 Conclusions .............................................................................................................546.2 Recommendations ...................................................................................57REFERENCES............................................................................................................................58APPENDICES.............................................................................................................................63 iv
  • 5. ACKNOWLEDGEMENTWe would like to thank the Zambia Investment Social Fund (Zamsif) for financial support toundertake the study under the Poverty Monitoring and Analysis (PMA). We also thank theEnvironmental Engineering Laboratory of the School of Engineering and the Food ScienceLaboratory in the School of Agricultural Sciences of the University of Zambia for carrying outthe water quality testing and the quality testing of crops for heavy metals, respectively. Theirlarge contribution to the study is gratefully acknowledged.We would also like to extend our thanks to the research assistants Cosmas Chalo and SiwaleChisanga (all employees of Department of Water Affairs), Mainess K. Manninga (member ofWater and Sanitation Association of Zambia), and Constancy Zulu (student of University ofZambia in the School of Natural Sciences) who assisted in administering the questionnaires,data entry and data analysis. We also appreciate the service rendered by the Water andSanitation association of Zambia (WASAZA) for assisting in making use of the printer. v
  • 6. LIST OF TABLESTable PageTable 2.1: WHO and EU Drinking Water Quality Guidelines for Heavy Metals and Threshold Values Leading to Crop Damage (mg/l)………………..……………7Table 2.2: Recommended Revised Microbiological Quality Guidelines for Wastewater Use in Agriculture ...........................................................................12Table 4.1: Parameters sampled and methods used for analysis .......................................23Table 5.1: Gender and age of respondent regarding use of wastewater for irrigation......26Table 5.2: General agricultural practices in the study areas ..............................................27Table 5.3: General crop selection by farmers in the two study areas ................................29Table 5.4: Comparative methods of marketing crops practiced in Ngwerere and Kafue Lagoon area……….. ................................................................................31Table 5.5: General crop growing season, acreage, yield, unit and unit price in the Kafue Lagoon area.. ...........................................................................................33Table 5.6: Farmers’ total income in Kafue Lagoon and Ngwerere River Areas ................33Table 5.7: General crop growing season, acreage, yield, unit and unit price in the Ngwerere area……………….. ............................................................................34Table 5.8: Clinical data from Kasisi Rural Health Centre showing prevalent diseases in Ngwerere area.................................................................................35Tables 5.9: Constraints faced by farmers in growing their crops/vegetables ......................36Table 5.10: Exploratory Analysis of Heavy Metals in Crops at Ngwerere River and Kafue Lagoon Areas ...........................................................................................39Table 5.11: Physical and chemical parameter of water sample analysis from Ngwerere River three sampling sites ..................................................................................41Table 5.12: Physical and chemical parameter of water sample analysis from Ngwerere River three sampling sites and their standard deviations .................................42Table 5.16: Physical and chemical parameter of water sample analysis from Lee Yeast compared with ECZ effluent and wastewater standards...................................48Table 5.17: Sodium Adsorption Ratio for Ngwerere River....................................................50Table 5.18: Bacteriological analysis in the Ngwerere at three sampling sites showing organisms per 100ml ..........................................................................................50Table 5.19: Bacteriological analysis in the Kafue Lagoon area at three sampling sites showing organisms per 100ml............................................................................51Table 5.20: Ranges of Contamination and Recommendations (after Westcot, 1997)........51Table 5.21: Analyzed sediment quality from Ngwerere three sampling sites compared to Dutch Sediment Quality Guidelines ...............................................................53 vi
  • 7. Table 5.22: Analyzed Shikoswe stream and Lee Yeast sediments from the Kafue Lagoon area compared to Dutch Sediment Quality Guidelines..................53 LIST OF FIGURESFigure PageFigure 5.1: Water sources used for irrigating crops in Kafue Lagoon.....................................30Figure 5.2: Conveyance of water for irrigation in Kafue Lagoon Area ....................................30Figure 5.3: Conveyance of water for irrigation in Ngwerere River ..........................................31Figure 5.4: Market channels for crops grown in the Ngwerere River Area.............................32Figure 5.5: Mechanism in Marketing of Produce by Farmers in Kafue Lagoon……………...32Figure 5.6: Ngwerere River mean monthly flows .....................................................................37Figure 5.7: Flow Duration Curve for Ngwerere River...............................................................38Figure 5.8: Total, Base-flow and Surface Runoff .....................................................................38Figure 5.9: Total hydrograph and Base-flow from October 2002 to August 2003 ..................39Figure 5.10: Logarithmic plot of microorganisms at 3 sites along Ngwerere River ................52Figure 5.11: Logarithmic plot of number of microorganisms at 2 sites at Kafue Lagoon..….52 vii
  • 8. LIST OF PLATESPlate Page Plate 5.1: A plot of Rape in Ngwerere River Area near Ngwerere Estate Weir................28 Plate 5.2: Plots of Rape in Chamba Valley near the Ngwerere River...............................28 Plate 5.3: Below Spill way at Kasisi Dam (third sampling point) .......................................45 Plate 5.4: Crop in Kafue Lagoon Area near effluent channel from Lee Yeast..................49 Plate 5.5: NCZ effluent channel near the footbridge on the Left side of the picture (Sampling point)………………............................................................................49 Plate 5.6: Shikoswe stream carrying sewerage effluent near NCZ going into the Lagoon (NCZ right side of the picture)…………………………..……………….49 viii
  • 9. LIST OF APPENDICESAppendix ........................................................................................................................PageAppendix I: Questionnaires for the project on the use of nutrient enriched water for growing food crops in the Ngwerere river catchment and at the Kafue Lagoon Areas......................................................................................................63Appendix II: Table A.1: Wastewater treatment and quality criteria for irrigation (State of California 1978)...................................................................................................69Appendix III: Irrigation Water Quality Guidelines ....................................................................70Appendix IV: Table 2B: Recommended Maximum Concentrations of Trace Elements in Irrigation Water....................................................................................................71Appendix V: Table C. 3: Constituents of concern in wastewater treatment and irrigation using reclaimed municipal wastewater ..............................................................72Appendix VI: Questionnaire results ..........................................................................................73Appendix VII: Analyzed water quality data from Ngwerere River sampling points .................81Appendix VIII: Analyzed water quality data from Kafue Lagoon Area ....................................83Appendix IX: Analyzed sediments from Ngwerere area from Ngwerere sampling points......84Appendix X: Analyzed sediments from Kafue Lagoon Area....................................................85Appendix IX: Base flow index calculation for Ngwerere Estate Weir ......................................86Appendix XII: Current national water quality standards in use in Zambia ..............................87Appendix XIII: Results of effluents from Nitrogen Chemicals of Zambia (NCZ) .....................88Appendix XIV: Chemical analysis of effluents from Lee Yeast Factory ..................................89Appendix XV: Rapporteur’s Report...........................................................................................97 ix
  • 10. Abbreviations and AcronymsBOD Biochemical Oxygen DemandCd CadmiumCOD Chemical oxygen DemandCu CopperDFID Department for International DevelopmentDO Dissolved OxygenDWA Department of Water AffairsECZ Environmental Council of ZambiaEU European UnionFDC Flow Duration CurveHg MercuryLCC Lusaka City CouncilMFNP Ministry of Finance and National PlanningNCZ Nitrogen Chemicals of ZambiaNSR National Scientific ResearchPb LeadPMA Poverty monitoring AnalysisPRSP Poverty Reduction Strategy PaperWHO World Health OrganizationWSP Waste Stabilization PondsZESCO Zambia Electricity Supply CorporationZn ZincZNS Zambia National Service x
  • 11. Executive SummaryIntroductionIn urban and peri-urban zones in developing countries, poor farmers commonly use nutrient-enriched sewage and wastewater to irrigate high-value crops. In many places, this untreatedwastewater is their only source of irrigation water-so their livelihoods depend on it. On the otherhand, the unregulated use of wastewater also poses risks to human health and theenvironment. Wastewater irrigation can also significantly contribute to urban food security andnutrition. Recent studies in several Asian and African cities have revealed that wastewateragriculture has accounted for over 50% of urban vegetable supply. it is estimated that one tenthor more of the world’s population currently eats food produced on wastewater (but not alwaysin a safe way).In Zambia despite the health hazards associated with crops grown in the Kafue Lagoon usingwastewater from Nitrogen Chemicals of Zambia (NCZ), Shikoswe stream and Lee Yeast, trucksloaded with a variety of vegetables and sugar cane came from Kafue about 50 kilometressouth-west of Lusaka to Kamwala and Soweto markets to sell these products. Most of thismerchandise bought in bulk by marketers was sold to unsuspecting consumers. But manyKafue residents earned their living by growing and selling these crops in the lagoon usingeffluents from canals carrying industrial and domestic wastewater.Similarly the Ngwerere River has its share of urban and peri-urban agricultural activities despitethe river being biologically polluted. it was demonstrated that the river exhibited significant self-purification capacity along its stretch from Garden Compound to the confluence with theChongwe River. The current study incorporated BOD, COD, and total nitrogen and flowmeasurements as recommended in previous studies. The current study also linked wateranalysis to the users of water, a link that was left out in previous studies.Main objectiveThe main objective of the study was to assess the effects of using wastewater on vegetablegrowing and the associated socio-economic impacts on farmers in the Kafue Lagoon Areasand along Ngwerere River.Literature reviewIntroductionDomestic human waste is defined as human excreta, urine, and the associated sludgecollectively known as black-water, as well as, kitchen wastewater and wastewater generallythrough bathing (collectively known as grey-water). Wastewater defined as waste matterentering water and its disposal involves the collection, treatment, and sanitary disposal. Thesources of wastewater are domestic, industrial, storm water and by groundwater seepageentering municipal sewage network. Wastewater is composed of organic matter, nutrients,inorganic matter, toxic chemicals and pathogens. Reclaiming municipal wastewater foragricultural reuse is increasingly recognized as an essential management strategy in areas ofthe world where water was in short supply. Wastewater reuse in agriculture requiredconsideration of the health impact, agricultural productivity, economic feasibility andsociocultural aspects.Treatment of wastewater xi
  • 12. In Zambia stabilization ponds are used for treating wastewater. These consist of the anaerobic,facultative and maturation ponds. Anaerobic ponds receive effluents of high organic loadingand have retention time of one to five days and depth of 2-4 meters. Facultative ponds areused to treat the wastewater and generally have a depth of 1-1.5 meters. The retention time forthe wastewater is 5 to 30 days. Maturation ponds on the other hand, remove faecal bacteriaand the retention period of the effluent is 5-10 days and their depth is 1-1.5 meters. In principle,a natural pond could be aerobic, facultative, or anaerobic.Quantity of wastewaterDomestic sewage resulting from people’s day-to-day activities, such as bathing, bodyelimination, food preparation, and recreation, averages about 227 litres (about 60 gal) perperson daily. Raw sewage included waterborne waste from toilets, sinks and industrialprocesses. The average monthly water consumption for an average household size of 7.5inhabitants living in high/medium cost areas and 6.0 inhabitants living in low cost Area (asfound valid in various urban centres in Zambia) were 50, 690 cubic meters per month and 43,446 cubic meters per month respectively. 17 percent of the households in Zambia used flushtoilets. The quantity of industrial wastewater varies depending on the industry and managementof its water usage, and the degree of treatment before it is discharged. Domestic wastewaterconsists of about 99.9 percent water and 0.1 percent solids.At the time of the study, Manchichi Sewage Treatment Plant was discharging effluents to theNgwerere River. Prior to discharging, the wastewater was treated using biological filters andthen pumped to the maturation pond in Garden Compound. In April, May, June and July 2004the average discharges from Manchinchi were 72, 545 m3/day, 58,805 m3/day, 39, 357 m3/dayand 32, 803 m3/day, respectively. The design capacity of the treatment plant was 36, 000m3/day. Therefore for April, May and June 2004 the design capacity was exceeded. Thesefigures were obtained from Lusaka Water and Sewerage Company. As a result of overloadingthe treatment plant, the final effluent lost its quality to 59 % removal efficiency in terms of BOD,23 % in terms of COD and 52 % in terms of TSS due to untreated raw sewage from the Plantby-pass line.Toxicology aspects of wastewaterIt is widely accepted that levels of trace elements and heavy metals in irrigation water werelikely to be toxic to plants at concentration below that which they pose a significant risk tohuman health. Heavy metals in wastewater posed a health risk if they were ingested insufficient concentrations, and could be dangerous. In principle, uptake of heavy metals bycrops and the risk posed to consumers may not be an issue as plants could not resist highconcentrations of these pollutants and die off before they become a threat to humans. Thisprovides a degree of natural protection of irrigators and consumers as plants fail to thrive andfarmers abandon the source well before levels present a risk to human health. There arecurrently no guidelines for permissible levels of trace elements and heavy metals in wastewaterused for irrigation, which relate to the potential risk to human health as a consequence of cropuptake and bio-accumulation.Apart from heavy metals and trace elements, wastewater also contains high concentrations ofdissolved salts. Salinity-related impacts of wastewater irrigation on soil resources could beexpressed in economic terms such as (1) potential yield and income loss; (2) loss of soilproductivity; (3) depreciation in market value of land; and (4) cost of soil reclamation measures.Cost benefit of using wastewater xii
  • 13. Irrigation with wastewater could be an attractive way of disposing wastewater from anenvironmental point of view. The combined benefits of reduced treatment and disposal costand increased agricultural production may justify investment in an irrigation system.Wastewater has phosphates and nitrates, which can be channelled onto land as fertilizers.Other important uses of wastewater include recharge of groundwater, as cooling water inindustry, recreational water, construction and dust control, wildlife habitat improvement,aquaculture and municipal non-portable uses such as landscape and golf course irrigation.Reuse of (pre) treated wastewater, especially in agriculture, can considerably contribute towater resources conservation, recycling of nutrients and prevention of surface water pollution.Agronomic and public health aspectsWhile wastewater is a resource for productive uses, it can be dangerous if used in an untreatedform. The dangerous practice of direct and indirect use of untreated wastewater was commonin regions like Lima, Mexico City, and Santiago. This is a serious concern with respect to publichealth. The use of untreated wastewater for irrigation poses a high risk to human health in allage groups. Untreated wastewater irrigation led to relatively higher prevalence of hookwormand Ascariasis infections among children. The DFID-sponsored research in North-east Brazilshowed that bacterial pathogens such as Vibrio cholerii, Salmonella species andCampylobacter species were present in wastewater.Irrigation methodsSome crops can be irrigated using unrestricted guideline of the WHO. Unrestricted irrigationrefers to all crops grown for direct human consumption and eaten raw (e.g., lettuce, salads,cucumber) and also the irrigation of sports fields, public parks, hotel lawns, and tourist areas.Restricted irrigation refers to the irrigation of crops not intended for direct human consumptionand there should be no more than one viable human intestinal nematode egg per litre, implyinga greater than 99% treatment level. This guideline was introduced to protect the health of fieldworkers and to indirectly protect consumers and grazing cattle. Restricted irrigation can beapplied to industrial crops (e.g., cotton, sisal, and sunflower, wheat, barley, oats); and fruittrees, fodder crops and pastures.Sociocultural aspectsPeri-urban and urban agriculture are understood to be the agricultural activities undertakenwithin the area immediately surrounding the city, where the presence of the city had an impacton land use, property rights and where proximity to the urban market and urban demand drovechange in agricultural production. Furthermore, urban agriculture is one of the severalstrategies used by the urban and peri-urban dwellers to cope with poverty.A physical, natural resources-oriented survey complemented by a socio-economic study of thecommunity affected by the reuse project would reveal the need for reuse. The acceptance ofwastewater reuse and the adoption of practices for its safe implementation will be influenced bythe sociocultural makeup of the people involved (that is the values, beliefs, and customs thatare concerned with water supply, sanitation, hygiene and other activities related to water use).There were few reconnaissance-type studies that describe sociocultural aspects of reuse.The social concerns about the potential risk of wastewater irrigation originated from concernsregarding impacts on environmental quality, public health and safety. These concerns may beaddressed with appropriate educational and public awareness programs. The cost of publiceducation, awareness and demonstration programmes could be used as a choice for thevaluation of social impacts of wastewater irrigation programmes, using awareness andsensitization educational models. xiii
  • 14. Policy aspectsThe Zambian National Water Policy of 1994 specifies that water for irrigation should be fit forhuman consumption and not cause soil degradation but enhance high crop yield. Within thebroad objective for agriculture, the Poverty Reduction Strategy Paper (PRSP) indicated thatsince the poor often relied on the environment for their livelihood, attacking poverty in ruralareas was necessarily improving people’s ability to derive livelihood from natural resources. Onthe other hand, the Zambian Health Policy fosters that in order to have a well-nourished andhealthy population that could contribute to the national economic development there was needto achieve sustainable food and nutrition security.Study areasKafue Lagoon AreaThe study focused on two study areas. The Kafue Lagoon area and along the Ngwerere river.The Kafue lagoon Area is located about 45km south of the City of Lusaka. The Area spans atotal of over 50 hectares of land under mostly sugar cane cultivation. Sampling was done atthree locations; Shikoswe Stream, Lee Yeast effluent stream and effluent canal from NitrogenChemicals of Zambia (NCZ). Questionnaire administration was not restricted to the watersampling locations.Ngwererer River AreaThe Ngwerere is a small river whose origin is in the city of Lusaka and it stretches over adistance of approximately 30 kilometers. The catchment size is 662 km2. The sampling andquestionnaire administration took place at three locations along the river, namely Near GardenSite 3 pond in Garden compound (N1), at Ngwerere Estate Weir (N2) in Chamba Valley areaand at Kasisi Mission Dam diversion (N3).MethodologyThe methods used during the study were both qualitative and quantitative in the generation ofinformation as well as documenting the findings. Various documents were reviewed on thework done on utilization of wastewater or nutrient enriched water in Zambia and other parts ofthe world. Various legislative articles from institutions such as the Environmental Council ofZambia, Department of Water Affairs and Ministry of Health were also reviewed. Otherdocuments such as the WHO guidelines and ECZ wastewater standards on the safe use ofwater for irrigation were also reviewed.Information was gathered by using a combination of observations, field surveys and structuredinterviews with selected growers. Surveys were carried out to ascertain the types of cropsgrown within the Ngwerere catchment and at Kafue Lagoon area. Questionnaires wereadministered in the field to gather information on how the communities or peasant farmers’value enriched wastewater in irrigation. The sample size used was 30 respondents from KafueLagoon and 42 respondents from the Ngwerere Area.The sampling technique used before administering the questionnaires was sampling by a GridSystem technique. The Grid System method involved putting a screen with squares on a studymap and the areas falling within selected squares were selected samples.The quantity of wastewater in the Ngwerere stream was computed by analysing thehydrological data from the Ngwerere Hydrological Station of the Department of Water Affairs(or N2 sampling station). Hydata and Arida software were used to compute the total surfacerun-off and then separating the base-flow from the total surface runoff in cubic meters. xiv
  • 15. A total of eight (8) sampling campaigns at each site in Ngwerere and four (4) at each site inKafue were carried out between 6th July 2004 and 20thAugust 2004. In total two (2) campaignsin Ngwerere involved one (1) duplicate sample for each site and in Kafue two (2) campaignsincluded one (1) duplicate sample at three (3) sites.The full stretch of the Ngwerere River was surveyed to select three points for sampling (water,sediment, plants) and testing over a period of 2 months. Being a narrow channelled stream, theNgwerere was assumed to be completely mixed over its depth and width. A grab sample in themiddle of the stream was considered representative enough. The water sample was obtainedby immersing a sample bottle about 5cm below the water surface and collecting the water. Forchemical analysis a polythene bottle (1000ml) was used while for heavy metals a 500ml bottlewith 2ml nitric acid inside was used. Sterilized glass bottles were used for microbiologicalsampling. The bottles were then kept in a cool box packed with ice blocks. Another 1000ml-polythene bottle was used to store bottom sediment, which was scooped from the riverbedwhere it had accumulated. This was stored separate from the water samples.In-situ water quality tests of water temperature, pH, conductivity and salinity were carried outusing the Horiba Water Checker U-10 model. Crop samples were collected in Chamba Valleynear Ngwerere Estate Weir (N2). Only the leaves of rape were collected and taken to FoodScience Laboratory at the University of Zambia in the School of Agriculture.Three points for sampling were selected to cover the effluent canals, which were used forirrigation by farmers in the lagoon area. The effluent canals were the Shikoswe stream, Leeyeast effluent canal and Nitrogen Chemicals of Zambia. Water, plant and sediment sampleswere collected at these points. The collection of samples was similar to NgwerereThe samples were analysed at the Environmental Engineering laboratory of the School ofEngineering at the University of Zambia. The samples were transported to the laboratory within7 hours of sampling. The methods of analysis of parameters included gravimetric, titrimetric,photometric and electrometric determinations for physicochemical parameters, atomicabsorption spectrometry for heavy metals and membrane filtration method for microbiologicalparameters. For quality control/assurance, duplicate samples were obtained during selectedsampling campaigns and some samples taken to an independent laboratory for crosschecking.Data was analyzed using excel spreadsheet, Arid Region Drought Analysis (ARIDA) andHydrological Data Analysis (Hydata) software, graphs and tables.Results and discussionField interviewsKafue Lagoon AreaIt was found that 60% of the farmers producing irrigated crops in Kafue Lagoon Area werewomen and only 40% were men. On the other hand, Ngwerere Area presented the oppositescenario with 81% of the farmers being men and only 19% women.In Kafue Lagoon Area the educational levels of the respondents varied; 26% didn’t have anyformal education and 74% had (17% had secondary level education and 57% had gone up toprimary level). The main occupation of respondents in the Lagoon was gardening whilst thesecond occupation included various activities such as selling of charcoal, piecework andkeeping of livestock.The main source of income for the peasant farmers in Kafue Lagoon Areaswas from sale of vegetables, sugar canes and gardening. xv
  • 16. Ngwerere River AreaIn Ngwerere River Area the education levels of the respondents were such that 14% had noformal education and 86% had formal education (31% - secondary level education, 53% - up toprimary level and 2% - up to tertiary level). The main occupation of the respondents in theNgwerere River Area was producing and selling of vegetables and maize. The main sources ofincome for the peasant farmers in Ngwerere River Area were selling of vegetables andgardening. The alternative sources of income were retirement package (pension money), rentalfrom houses, business and piece of work, selling of pesticides.Land tenureLand tenure was leasehold, farmer’s own land, Zambia National Services land or communalland in the Ngwerere Area and main crops grown were vegetables and maize. In the KafueLagoon Area land tenure was freehold. The cropping pattern was composed of vegetables,maize and sugar cane.Water management and sourcesIn the Kafue Lagoon, 32% of the respondents relied on shallow dug out wells while 68% usedcanals. The canal water mostly used came from the Nitrogen Chemicals of Zambia (NCZ)canal. The water was conveyed onto the fields by watering cans or buckets and furrows. Themajor water source for irrigation was the Ngwerere River and the most common method ofapplying water was to collect from the stream or river, and to apply it to the crops using watercans or buckets (10 to 20 litre containers). This was a laborious task.Marketing of cropsThe single commonest means of marketing the produce in Ngwerere was for growers to selltheir produce at markets: Soweto, Town Centre, Kabanana, Chipata Compound, Ng’ombe,Katambalala, Chaisa, Garden, and Kaunda Square markets, which was at 69%. Five (5)% ofthe farmers sold their produce to Fresh Mark in Lusaka town. It was also found that 83% of thefarmers marketed their crops individually, 12% as a formal group, 3% as traders whopurchased the produce from the farmers. In Kafue all the respondents sold theircrops/vegetables individually in different parts of Kafue (Kalukungu, Kafue Estates, ZambiaCompound and Solloboni markets), Chilanga and Lusaka (urban and rural) including Chirunduin Siavonga.The yield of vegetables varied from one respondent to the other and the figures were based onthe data obtained from the farmers through interviews. A further analysis of income andexpenditure pattern at household level could be a subject of another research.Earnings from crop salesThe income realized from the sale of different crops varied depending on the type of crop,number of customers and season (with respect to price). In the Kafue Lagoon Area, thefarmers’ income ranged from K800, 000 to K1, 000,000 per year while in Ngwerere River Areait ranged from K400, 000 to K2, 500,000 per year. The Ngwerere farmers had wider marketcoverage and relatively shorter distances to bigger markets and had higher demand for thecrops.Constraints faced by farmersThe major constraints faced by farmers in growing their crops/vegetables were inadequatetechnical support, conveyance of water onto field, crop storage, and transport expenses (tomarkets), lack of credit for capital investment and price variation xvi
  • 17. Public health issuesIt was found that the prevalent diseases in the study Area were malaria, bilharzias anddiarrhoea. For the Ngwerere Area, secondary data obtained at Kasisi Rural Health Centreconfirmed the findings. Malaria topped the list as the most prevalent, followed by diarrhoea,bilharzias and lastly dysentery. Other parts of the river catchment near stabilization ponds ingarden Compound and near overgrown parts of the river were likely to be affected by thesediseases. Fifty four percent (54%) of the respondents in Ngwerere catchment said the riverwater was not fit for drinking but was good for irrigation. However, fifty percent (50%) of themsaid none of the members of their household had suffered from any disease associated withthe river water in the past one year. The case at Kafue Lagoon was quite similar to theNgwerere situation. Fifty three percent (53%) of the respondents said the water used forirrigation posed a threat to human health while fifty percent (50%) said none of the members oftheir household had suffered any illness as a result of the water they used for irrigation.Quantity of wastewater in the Ngwerere River AreaThe total surface runoff and base-flow was computed by using the Hydata, spreadsheet andARIDA software at the Department of Water Affairs Water Resources Unit were used. Thesurface runoff was estimated by using Flow Duration Curves (FDC). The groundwater storagein the Ngwerere catchment contributed significantly (as base-flow) to the total surface runoff,enough to keep the stream flowing during the study period.Plant sample analysisMercury and copper were not detected in all the plant samples. This could mean that it was notpresent as a waste product. Given the high pH values copper could have precipitated out ofsolution into the sediments and so not much of it was available for the plant uptake afterirrigation. A previous study by Sinkala et al in 1996 reported less than 0.02 mg/l (detection limit)of Cu in the wastewater from NCZ and less than 0.011 and 0.018 mg/l (detection limits) of Cuin Lee Yeast effluents.Documents indicated that cadmium could be present in the water column at very lowconcentrations and yet build up in the plant tissue to levels that were harmful to human health.For Cd the recommended maximum concentration was 0.01 mg/l in water. Others like Pb it was5.0 mg/l, Zn 2.0 mg/l and Cu 0.20 mg/l. In the absence of local guideline values for heavymetals in plants against which comparisons could have been made, guideline values from astudy (personal communication) were used: 50 mg/kg as maximum concentration of Cu andZn, and 5mg/kg of Pb in plant tissues. Apart from Cd (0.028 to 0.049 mg/l), all the other heavymetals analysed were below the recommended maximum concentrations in plants. Cd mightbe a threat to human health in both study areas but further investigations would be required toquantify and mitigate the threat.Water quality analysisWestcot argued that the WHO or Engelberg standards for faecal coliform were designguidelines and suggested that in the absence of better information, it was “prudent” to use themas the quality standard to aim for in waters that were known to currently fall short of that quality.Therefore, in the current study, the water quality was interpreted with respect to the WHOguidelines and recommendations by Westcot considering the fact that adequateepidemiological and water quality information was not available at the time of the study.The water at both Ngwerere and Kafue Lagoon Area was potentially safe for irrigation as longas the pollution sources were eliminated. But elimination of the sources of pollution was not xvii
  • 18. feasible in both situations because the contaminated water was also the water used forirrigation by the peasant farmers in these areas and was their main source of income and food.Other options such as improving the efficiency of wastewater treatment plants (especiallydesludging) upstream or expanding the treatment plants could be considered. There werelarge variations in the faecal coliform numbers at each point on the Ngwerere River over thestudy period, hence high standard deviations. This was probably due to variation in wastewaterdischarges and composition, flow pattern of the river and its tributaries and abstraction forirrigation. Such variations in coliform counts were also reported in a study in Ghana carried outby Cornish.In terms of the spatial distribution of the more microorganisms on the Ngwerere River werefound upstream in the urban/peri-urban area of Lusaka City (N1 and N2) than downstream inthe rural area.Effluents from Lee Yeast and Shikoswe were also heavily contaminated with respect to faecalcoliform. The water was not safe for use without treatment.Most of the parameters including conductivity, salinity, calcium, sulphate, total nitrogen, totalphosphate, BOD, total suspended solids and iron tended to reduce in concentration from theupstream reaches in the urban area to the downstream reaches in the rural area of the rivercatchment. This indicated that the pollution was heavier in the former than in the latterstretches of the river. There were no heavy metals detected in the water samples. Metals likeCu and Pb easily precipitated out of solution at high pH values (8-10) as found in the river.Generally the physicochemical parameters for Ngwerere River were within the limits of theECZ, WHO, DWA and EU guidelines for water quality. However, the pH was higher than therecommended upper limit of 9 in a few cases especially at Kasisi Mission. Ammonia levels atN1 and N2 (that was urban and peri-urban areas) were higher than the WHO drinking waterguideline value of 0.5mg/l. On average sodium was higher than the guideline value of 200mg/l,which could lead to the problem of specific ion toxicity. TSS at N1 and N3 were also higherthan the ECZ guideline value of 100mg/l.Though most of the physical and chemical parameters were within the recommended limits forirrigation and other water uses, microbiological parameters showed that the river was heavilypolluted. Throughout the river stretch, the water was not suitable for drinking and at somepoints even for irrigation according to WHO and FAO guidelines.All the other parameters measured were lower than the recommended maximum concentrationin irrigation water, according to Pescod. The concentration of heavy metals and boron in thewater at all the sampling points were below the detection limit of the method of analysis whichwas also far below the recommended maximum concentrations.From the results it was clear that the main problem with respect to the risk to human health wasthe pollution by microorganisms in the watercourses where the farmers drew water for irrigatingtheir crops. This was common in both study areas –Ngwerere River and Kafue Lagoon.For Ngwerere River only the last point (N3, Kasisi Mission, about 23 km from source) qualifiedfor unrestricted irrigation according to the WHO guideline value of ≤1000 faecal coliform/100ml,if only the mean value for July 2004 was considered (900 faecal coliform/100ml). Underunrestricted irrigation vegetables and salad crops could be grown using water with ≤1000faecal coliform/100ml. Therefore, the growing of vegetables at the other sites (N1 and N2)posed a health risk to workers (or producers) and the consumers. On the other hand the water xviii
  • 19. in the Ngwerere River was only fit for restricted irrigation whereby the crops that could be safelygrown were cereal crops, industrial and folder crops, and pasture and trees (fruit trees).The reduction in pathogens at the lower reaches of the river (Kasisi Mission) was evidenced bythe reducing counts of E.coli and Faecal streptococci. At all the stations on the river the waterwas not suitable for drinking. Previous studies also demonstrated a similar pattern andmoreover some of the sampling points used in this study were also used in the past studies.In Kafue Lagoon Areas, the Shikoswe and Lee Yeast effluent streams also had their meanvalues above the WHO guideline of <1000 faecal coliforms/100ml.For NCZ, the parameters measured were within the ECZ recommended limits. This was verydifferent from the situation in 1996 under the study of Sinkala et al, which reported higher levelsof magnesium, calcium, total suspended solids and total dissolved solids. The difference maybe attributed to slowed or no production at NCZ at the time of the present study. In fact thewater in the effluent canal was visibly clear. At the time of sampling it was found that thefarmers were mixing this water with that from Lee Yeast factory and Shikoswe stream throughdiversion canals.For Lee Yeast the conductivity was higher than the recommended standard of 4300uS/cm(ECZ). The phosphate and calcium levels were abnormally higher that the recommended limitsby ECZ although this was just for one sample. High calcium and conductivity (as TDS) levelswere also reported by Sinkala et al (1996). The source of the calcium was mainly the geologyof the area. The high conductivity corresponded to high sodium content of the effluent.The parameters measured at NCZ, were within the ECZ recommended limits. This was verydifferent from the situation in 1996 in the study of Sinkala et al, which reported higher levels ofmagnesium, calcium, total suspended solids and total dissolved solids. The difference may beattributed to slowed or no production at NCZ at the time of the present study. In fact the waterin the effluent canal was visibly clear. At the time of sampling the farmers were mixing thiswater with that from Lee Yeast factory and Shikoswe stream through diversion canals.As in Ngwerere the concentration of heavy metals and boron in the water at all the samplingpoints were below the detection limit of the method of analysis which was also far below therecommended maximum concentrations.The Shikoswe effluent had relatively high levels of ammonia and phosphate, the reason beingthat it carried mainly sewage effluents. As in Lee Yeast effluents, Shikoswe also had highlevels of iron. However, iron posed no known threat to human health.The high salt content (as conductivity) of the irrigation water used at both study sites,threatened the well being of the soil in the fields under irrigation. The sodium adsorption ratio(SAR) at N1, N2 and N3 and at Kafue Lagoon Areas (NCZ) were 31, 28, 32 and 22,respectively. The values were higher than the Ayers and Westcot (1985) guideline value of 9(beyond which the fields under irrigation would experience severe specific ion toxicity affectingsensitive crops and also increasing soil salinity problems. High salinity led to reduced uptake ofwater and nutrients by plants.The sediment samples were analysed at both sites for exploratory purposes. Detailedinvestigations should be carried out in future. The spot samples analyzed would help to explainor confirm variations in the other sample types in limited mass balance terms. xix
  • 20. The first two sites (N1, Garden/Olympia area and N2, Ngwerere Estate Weir) on the NgwerereRiver had a higher concentration of Zn, Fe, Pb and Cu in sediment than at the last site (N3,Kasisi Mission. At Kafue lagoon and Ngwerere the highest concentration of iron was 1503 and1596 mg/kg iron, respectively. Cd (<0.002) and Hg (0.0002) concentrations were below thedetection limit of the method of analysis at all the sampling points in the two study sites,suggesting that very little quantities of the two metals were introduced in the watercourses.Since there were no local guidelines for heavy metals in sediments, the results in this studywere compared with the standards for polluted sediments in the Netherlands. although thiscountry was more industrialized than Zambia. From the comparison with Class I (best class)out of four classes, all the samples were way below the maximum heavy metal classconcentrations except for Cu (58 mg/kg) at Shikoswe stream, which was very high. But thiswas a one off value, which would require further verification.ConclusionBased on the findings from the study, the following were the conclusions: The growing and selling of crops in both study areas was the main source of cash income and food for most of the peasant farmers The average income earned from sale of crops ranged from K800, 000 to K1, 000, 000 in Kafue Lagoon and K400, 000 to K2, 500, 000 in the Ngwerere River Area. Using ECZ, WHO, EU, DWA, ZABS and other guidelines the suitability of the water for various uses especially irrigation was determined. It was found that the water in the Ngwerere River and Kafue Lagoon Area was suitable for restricted irrigation of folder crops, and fruit trees and but not for salad crops and vegetables except at Kasisi Mission (Ngwerere). The water at all sampling points was not suitable for drinking. Heavy metals in the water at all the sampling points were below the detection limit. The heavy metals in plant tissue and to some extent in the sediments were below the maximum recommended limits although bioaccumulation capacities of cadmium and lead need to be further investigated. There was no evidence of pollution by heavy metals that may pose a threat to the irrigated crop consumers during the study period. Health risks associated with the use of water in the Ngwerere and Kafue Lagoon Area could be reduced if the contaminants (especially pathogens) were reduced or eliminated at the source through improved treatment of wastewater The main irrigation method practiced during the study was the use of containers that accentuated the risk of contamination of the plants and farmers In both study areas the users considered the wastewater to be economically valuable for irrigating crops in spite of risks associated with using such water. Measurement of impacts of using the wastewater on crop yield would require a longer study period (not less than one year) than that allowed for the present study, and the same applies to seasonal variations in the quality and quantity of water used for irrigation. For instance the impact of high sodium adsorption ratio (SAR), averaged 30 for Ngwerere River water, could be understood better after collecting more data throughout the year.RecommendationsFrom the study the following were the recommendations:1. The Ministry of Agriculture and Cooperatives (MACO) should incorporate reuse of wastewater or nutrient enriched water in the irrigation strategy which aims at improving food security and poverty alleviation in the country xx
  • 21. 2. The Ministry of Health (MoH) and NGOs (e.g., Water and Sanitation Association of Zambia, CARE International and Lifegate Foundation) should sensitize and raise public awareness on health risks associated with using and handling of untreated or pre-treated wastewater3. The MoH, NGOs and other interested public and private institutions should support and fund surveys and research on reuse of wastewater and how waterborne diseases and helminth infestation could be prevented4. The government (e.g., through MACO and water user associations) should promote urban and peri-urban agriculture so that there is continued supply of food to the households5. The government should consider policy changes (especially Irrigation Policy, National Water Policy and National Environment Policy) with a view to incorporate urban and peri- urban agriculture as a legitimate urban land use6. The Ministry of Local Government and Housing (MLGH) should support the rehabilitation of the various sewerage treatment facilities7. The government should assist peasant farmers in forming urban farmers associations or co-operatives8. The government (through e.g., University of Zambia, National Institute for Scientific and Industrial research, National Science and Technology Council and MLGH) should focus on how the water quality could be improved through pre-treating wastewater prior to use, perhaps with small-scale wetland systems or shallow wells or other appropriate technology9. The government should support another study which to check the seasonal variation of the parameters and prevention of helminthes among irrigators and consumers from both study areas xxi
  • 22. CHAPTER 1: INTRODUCTION1.1 BackgroundIn urban and peri-urban zones in developing countries, poor farmers commonly use nutrient-enriched sewage and wastewater to irrigate high-value crops. In many places, this untreatedwastewater is their only source of irrigation water—so their livelihoods depend on it. On theother hand, the unregulated use of wastewater also poses risks to human health and theenvironment. Wastewater irrigation can also significantly contribute to urban food security andnutrition. Recent studies in several Asian and African cities have revealed that wastewateragriculture has accounted for over 50% of urban vegetable supply (IWMI, 2003). Wastewater isused as a source of irrigation water as well as a source of plant nutrients (such as nitrogen,phosphorus and potassium) and trace elements (K, Na, etc) allowing farmers to reduce or eveneliminate the purchase of chemical fertilizer and organic matter that serves as a soil conditionerand humus replenisher (IWMI-RUAF, 2002). The report by IWMI-RUAF (2002) as reported byLunven (1992) estimated that one tenth or more of the world’s population currently eats foodproduced on wastewater (but not always in a safe way).Wastewater reuse in agriculture is the economically feasible, environmentally sound use ofmunicipal wastewater for irrigation and aquaculture. Reclaiming municipal wastewater foragricultural reuse is becoming increasingly recognized as an essential management strategy inareas of the world where water is in short supply (Khouri et al., 1994). Wastewater reuse hastwo main objectives, that of improving the environment in that it reduces the amount of waste(treated or untreated) discharge into watercourses, and it conserves water resources bylowering the demand for freshwater abstraction. In the process, reuse has the potential toreduce the cost of both wastewater disposal and the provision of irrigation water, mainly bypracticing urban and peri-urban agriculture. Wastewater is defined as waste matter enteringwater (Huang, 1994). The sources of wastewater as indicated by Hussain et al., (2002) aremade up of domestic wastewater, industrial wastewater, storm-water and groundwaterseepage entering municipal sewage network. Domestic wastewater is made up of effluentdischarge from household, institutions, and commercial buildings. Industrial wastewater is theeffluent discharged by manufacturing plants. Wastewater is composed of organic matter,nutrients, inorganic matter, toxic chemicals and pathogens. The final composition of rawwastewater depends on the sources and its characteristics. Its disposal involves the collection,treatment, and sanitary disposal.Wastewater is used widely in both the industrialized and developing countries (Idelovitch andRingskog, 1997) and is increasingly seen as a resource, and it is often reused legally andclandestinely (Hussain et al., 2002; Idelovitch and Ringskog, 1997). Wastewater as a resourcecan be applied to productive uses since it contains nutrients that have the potential for use inagriculture, aquaculture, and other activities (Hussain et al., 2002). However, the same raw orpre-treated wastewater could pose health hazard to handlers and consumers of the cropsgrown using it (Westcot, 1997).Despite the health hazards associated with crops grown in the Kafue Lagoon due to the use ofNCZ wastewater for irrigation, findings by Enviro-line (1998) revealed that trucks loaded with avariety of vegetables and sugar cane came from Kafue about 50 kilometer south-west ofLusaka to Kamwala and Soweto markets to sell these products. Most of this merchandisebought in bulk by marketers is sold to unsuspecting Lusaka consumers. Many Kafue residentsearn their living by selling these crops grown in the lagoon using effluents from punctured pipesand from canals carrying industrial and domestic wastewater, to water their crops. 1
  • 23. Similarly the Ngwerere River has its share of urban and peri-urban agricultural activities despitethe river being chemically and biologically polluted (NSR, 1983). Later studies also proved thatNgwerere River was polluted (Tembo et al., 1997; Silembo, 1998). The report by Tembo et al(1997) and Silembo (1998) revealed, through laboratory investigation, that the water inNgwerere River was not suitable for drinking and but could be used for irrigation and fishingpurposes. The water would pose a health risk to the water users and consumers of crops. Itwas further demonstrated that the river exhibits significant self-purification capacity along itsstretch from Garden Compound to the confluence with the Chongwe River. For instance in1996, faecal coliform spatially reduced from 18, 000, 000 colonies per 100 ml in the upperreaches to less than 1000 colonies per 100 ml in the lower reaches near the Chongwe-Ngwerere confluence. In the lower reach water could also be safely used for fishing andwashing. At such low levels of coliform (1000/100 ml) and other parameters being acceptable,the water could be used for irrigation according to the WHO guidelines value of≤ 1000 per 100 ml for unrestricted irrigation and ≤ 100, 000 per 100 ml for restricted irrigation.Tembo et al (1997) recommended that future research on the river should incorporate totalnitrogen, biological oxygen demand and chemical oxygen demand tests in order to understandthe pollution of the river in greater detail.The current study incorporated BOD, COD, total nitrogen and flow measurements asrecommended by the previous studies. The research also linked water analysis to the users ofwater, a link that was left out in previous studies. Therefore socio-economic factors wereconsidered in the study.1.2 ObjectivesThe main objectives of the study was to assess the effects of using wastewater on vegetablegrowing and the associated socio-economic impacts on farmers in the Kafue Lagoon Areasand along Ngwerere River.Specific objectives1.2.1 To measure the impacts of using wastewater on crops/vegetables yield in the Kafue Lagoon and Ngwerere River areas, and how this is associated with the socio-economic status of farmers in these areas1.2.2 To analyze the wastewater for the relevant physico-chemical and biological parameters n order to determine the possible health hazards that may be associated with the use of such water1.2.3 To suggest measures of reducing health hazards associated with the use of wastewater in vegetables growing1.2.4 To determine environmental valuation of wastewater by the community and its contribution to poverty reduction.1.3 JustificationWastewater as a resource can be put to productive use. It can also be dangerous if used in anuntreated form, which poses high risks to human health. The dangerous practice of direct andindirect use of untreated wastewater is common practice in regions such as Lima, Mexico City.Reusing untreated wastewater in irrigation can lead to high prevalence of hookworms andAscariasis infections among all age groups. It may also contain bacteria pathogens such asVibro cholera, Salmonella and Campylobacter species. The negative environmental impacts 2
  • 24. associated with wastewater use are groundwater contamination through high concentrations ofnitrates, salts and micro-organisms.Though sewage wastewater is thought to be a health hazard, it is possible to make it good forseveral beneficial uses. Wastewater from the municipalities can be reclaimed for agriculturalreuse, which is increasingly recognized as an essential management strategy in areas of theworld where water is in short supply. Wastewater reuse in agriculture requires consideration ofthe health impact, agricultural productivity, economic feasibility and sociocultural aspects. Thewastewater used in developed countries is treated prior to its use in irrigation andenvironmental standards are applied. The wastewater is used to irrigate fodder, fiber and otherseed crops and, to a limited extent for the irrigating of orchards, vineyards, and other crops.The water and nutrient content found in wastewater is useful for agricultural purposes. Thenutrients and trace elements such as phosphorous, nitrogen and potassium are necessary forplant growth.Studies have indicated that urban agriculture (UA) is practiced inside (intra urban) or on theoutskirts (peri-urban) of a town or a city. This focuses on growing crops and raising animals. Italso includes recycling household waste and wastewater for agricultural purposes, theprocessing and distribution of different food and non-food products using human and materialresources, products and services that are found in the surrounding areas. An increasingnumber of local and national governments in countries such as Pakistani, Mexico and Moroccoare promoting UA in response to serious problems of poverty, food insecurity, andenvironmental degradation.Bearing in mind the hazards and benefits associated with wastewater reuse, there was needtherefore, to undertake this study and gain more insight into the situations at Ngwerere Riverand Kafue Lagoon areas where wastewater was increasingly used for irrigating crops andvegetables, which were mainly sold in Kafue town and Lusaka City. Since a lot of people inZambia spent time to grow crops as a means of earning a living in peri-urban and urbanagriculture, this would contribute a lot to poverty alleviation in the study areas. The study wouldenable the analysis of the costs and benefits of using such water for agriculture. Scientific datawas thus required to establish the relationship between the quality of water and crop yield.Greater yields would indicate that there is more income for peasant farmers and this couldhave a direct relation with poverty alleviation.1.4 Significance of the ParametersThe choice of parameters to be tested was based on the type of pollution expected from thedomestic and industrial wastewater since a considerable portion of the stream’s inflow is fromthese two sectors. The parameters tested were pH, temperature, conductivity, total suspendedsolids, BOD, COD, nitrates, ammonia, total phosphates, total nitrogen and E. coli, faecalstreptococci, faecal coliform, magnesium, calcium, boron, sodium, iron, lead, copper, cadmiumand mercury. The parameters, with an indication of their relevance, are listed in annex 15. 3
  • 25. CHAPTER 2: LITERATURE REVIEW2.1 GeneralDomestic human waste is defined as human excreta, urine, and the associated sludgecollectively known as black-water, as well as, kitchen wastewater and wastewater generallythrough bathing (collectively known as grey-water) (Rose, 1999). Wastewater as alreadydefined, is waste matter entering water and its disposal involves the collection, treatment, andsanitary disposal (Huang, 1994). According to Huang (1994) the issue of sewage disposalassumed increasing importance in the early 1970s. Hussain et al. (2002) noted that sources ofwastewater are domestic wastewater, industrial wastewater, storm water and by groundwaterseepage entering municipal sewage network. Domestic wastewater is made up of effluentdischarge from households, institutions and commercial buildings. Industrial wastewater is theeffluent discharged by industries. Wastewater is composed of organic matter, nutrients,inorganic matter, toxic chemicals and pathogens. The final composition of raw wastewaterdepends on the sources and its characteristics.According to Nicholas ODwyer and Partners Consulting Engineers, (1978) and WWI (1989) themost common analysis of wastewater includes the measurements of solids, biochemicaloxygen demand (BOD), total coliform, chemical oxygen demand (COD), chloride, sodium,phosphate, total nitrogen, calcium, temperature and pH. The solids include both the dissolvedand suspended solids. Sewage treatment proceeds in three stages in some countries –primary, secondary and tertiary stages. In the primary treatment stage, solid wastes areremoved through mechanical process and organic matter is removed by biological process inthe secondary treatment stage. The third stage is the tertiary treatment stage, which is thepolishing stage. Normally, it involves the removal of phosphorus and nitrogen.2.7 Treatment of WastewaterAccording to Proprasset et al (2000) any type of wastewater treatment system is based onnatural processes, be it chemical, physical or biological, and its design is aimed at creating theoptimum conditions for enhancement of the rate of these natural processes. Natural systemsfor wastewater management include a host of treatment techniques apart from the use ofstabilization ponds, which is common in Zambia. • Anaerobic treatment of wastewater is carried out in low-rate systems (septic tank or lined pit) or in high-rate systems (anaerobic filter, upflow anaerobic sludge blanket reactor, anaerobic contact process). All anaerobic systems are based on the degradation of organic material by a consortium of anaerobic bacteria. The process results in the production of biogas, which contains up to 80% of methane that can be re-used for electricity generation • Wetlands are plots of land where the water is at (or above) the ground surface long enough each year to maintain saturated soil conditions and the growth of related vegetation. Constructed wetlands are plots of land specifically designed to act as wetlands for purification of wastewater. The two types of constructed wetlands are free water surface and subsurface flow constructed wetlands • Macrophyte ponds are modified waste stabilization ponds. A cover of floating plants floats on the water surface. Plants such as water hyacinth (Eichhornia crassipes) and duckweed (Lemnacaea) are used to take up nutrients from the wastewater and to provide a pond environment that is not disturbed by wind action so that sedimentation is optimal 4
  • 26. • Water based fish-aquaculture transforms the nutrients that are present in wastewater into proteins. The fish feed on algae or macrophytes that grow using the nutrients • Terrestrial methods can be divided into slow rate (or irrigation) processes (SR), rapid infiltration processes (RI) and overland flow (OF) processesIn Zambia stabilization ponds are used for treating wastewater. These are comprised of theanaerobic, facultative and maturation ponds. Anaerobic ponds receive effluents of high organicloading and have retention time of one to five days and depth of 2-4 meters. Facultative pondsare used to treat the wastewater and have generally a depth of 1-1.5 meters. The retentiontime for the wastewater is five to thirty days. Maturation ponds on the other hand, removefaecal bacteria and the retention period of the effluent is 5-10 days and their depth is 1-1.5meters (GKW Consult, 2001). In principle, natural pond can be aerobic, facultative, oranaerobic. Aerated ponds are a manmade development and these reduce the amount of landrequired by adding artificial aeration.Stabilization or oxidation ponds are used extensively in developing countries. A relatively newsystem of natural stabilization ponds used extensively in Israel, and also in Spain, California,and Santiago, Chile, is the deep reservoir treatment, which consists of deep stabilization ponds(8-12 meters deep) (Idelovitch and Ringskog, 1997). Mara (1997) as cited by DFID indicatedthat these are used for both seasonal storage and effluent purification. The system can reducebacteria level in the effluent by as much as 99.999 percent depending on retention time (Mara,2000). In Northeast Brazil Waste Stabilization Ponds (WSP) comprise one or more series ofanaerobic, facultative and maturation ponds (Mara, 1997). The anaerobic ponds receive a highorganic loading that they are devoid of oxygen and BOD removals are very high over 70percent with retention time of only one day at 25oC.Facultative ponds (biological treatment) with a retention time of only 3-5 days at 25oC canreduce filtered BOD to well below the 25 mg/l EU requirement for WSP effluents and theoxygen needed by the heterotrophic bacteria are supplied through photosynthesis of the pondalgae (Mara, 1997). The wastewater treated in this way can be used for restricted irrigation.Aerobic bacteria convert the organic matter to stable forms such as carbon dioxide, water,nitrates, and phosphates as well as other organic materials (Huang, 1994). Nicholas ODwyerand Partners Consulting Engineers (1978) indicated that present treatment has very littleeffects on reducing the BOD of raw sewage, solid content, chlorides, sulfate, ammonia, andorganic nitrogen and trace metals.Maturation ponds are primarily used to ensure the removal of faecal bacteria and viruses tosafe levels so that the effluents can be used without risk to public health for crop irrigationand/or fish culture (Mara, 1997). Price (2003) indicated that the treatment and use ofwastewater is both a challenge and an opportunity for municipalities. It is a challenge becausethe use of non-treated wastewater is often the only option available for peri-urban farmers. Thisposes potential serious health problems of the presence of bacteria, viruses and parasites. It isan opportunity because wastewater is a valuable resource, not only from an economicviewpoint but also from an environment perspective (conservation of water resources, nutrientrecycling etc).At the time of the study, Manchinchi Sewage Treatment Plant was discharging effluents to theNgwerere River. Prior to discharging, the wastewater was treated using biological filters andthen pumped to the maturation pond (commonly called Garden Ponds). In June and July 2004the actual discharge from Manchinchi were 39, 357 m3/day and 32, 803 m3/day, respectively.The design capacity of the treatment plant was 36, 000 m3/day. Therefore for June 2004 the 5
  • 27. design capacity was exceeded. These figures were obtained from Lusaka Water and SewerageCompany. Average effluent discharge went up to 60, 000 m3/day. As a result of overloading thetreatment plant the final effluent lost its quality to 59 % in terms of BOD, 23 % in terms of CODand 52 % in terms of TSS due to untreated raw sewage from the Plant by-pass line. The riverdischarge at Garden/Olympia site (N1) which is downstream of Manchinchi WastewaterTreatment Plant discharge point on the Ngwerere River in August 2004 was 52,445 m3/day.Two other sources contributed water to the Ngwerere River at this point but clearly the largestsingle contribution (over 60%) came from the Manchinchi Wastewater Treatment Plant.2.3 Quantity of Wastewater ProducedAccording to Huang (1994) domestic sewage results from people’s day-to-day activities, suchas bathing, body elimination, food preparation, and recreation, averages about 227 litres (about60 gal) per person daily. Raw sewage includes waterborne waste from toilets, sinks andindustrial processes. The average monthly water consumption for an average household sizeof 7.5 inhabitants living in high/medium cost areas and 6.0 inhabitants living in low cost area(as found valid in various urban centers in Zambia) are 50, 690 cubic meters per month and 43,446 cubic meters per month respectively (GKW Consult, 2001). 17 percent of the householdsin Zambia use flush toilets. The quantity of industrial wastewater varies depending on theindustry and management of its water usage, and the degree of treatment before it isdischarge. Domestic wastewater consists of about 99.9 percent water and 0.1 percent solids.With increasing global population, the gap between the supply and demand for water iswidening and is reaching such alarming levels that in some parts of the world it is posing athreat to human existence (Hussain et al., 2002). Society on the other hand, is subjected tocontinuous expansion with increased food requirements and food insecurity.Lusaka Water and Sewerage Company is responsible for management of sewerage andsludge in Lusaka (ECZ and LCC, 1997). According to ECZ and LCC (1997) there are basicallyfour plants in Lusaka that handle the sewerage sludge produced in Lusaka; the Chelston andKaunda Square maturation ponds and the Chunga and Manchinchi conventional plants.Lusaka Province has 21 percent of households with flush toilets and 3 percent(communal/shared flush toilets), 35 percent (own pit latrine), 37 percent (communal/shared pitlatrine), 1 percent (other toilet facilities) and 3 per cent have no toilet facilities (CSO, 1998).Literature from CSO (2000 census) revealed that the total number of households in Lusaka is275, 000.2.4 Toxicological Aspects of WastewaterHide et al (2001) reported that it is widely accepted that levels of trace elements and heavymetals in irrigation water are likely to be toxic to plants at concentration below that which theypose a significant risk to human health (see Annex III). According to Hussain et al (2002) heavymetals in wastewater pose a health risk if they are ingested in sufficient concentrations, andcan be dangerous. In principle, uptake of heavy metals by crops and the risk posed toconsumers may not be an issue as plants cannot resist high concentrations of these pollutantsand die off before they become a threat to humans (see Table 2.1 and Annex III and IV). Thisprovides a degree of natural protection of irrigators and consumers as plants fail to thrive andfarmers abandon the source well before levels present a risk to human health. Hide et al (2001)indicated that there are currently no guidelines for permissible levels of trace elements andheavy metals in wastewater used for irrigation, which relate to the potential risk to humanhealth as a consequence of crop uptake and bio-accumulation. According to Hide et al (2001) 6
  • 28. most authors cite the table of phytotoxic threshold prepared by the National Academy ofScience and National Academy of Engineering (1972) and Pratt (1972), or refer to the WHOdrinking water guidelines (WHO, 1993). The data is indicated in Table 2.1.Table 2.1: WHO and EU Drinking Water Quality Guidelines for Heavy Metals and ThresholdValues Leading to Crop Damage (mg/l)Element WHO drinking water EU drinking water Recommended maximum guidelinesa guidelinesb concentration for cropcArsenic 0.01 0.05 0.1Cadmium 0.003 0.005 0.01Chromium 0.05 0.05 0.1Copper 2 0.2Iron 0.3 0.1-3.0 5.0Mercury 0.001 0.2 -Manganese 0.5 0.001 0.2Nickel 0.02 0.05 0.2Lead 0.01 0.05 5.0Zinc 3 0.1-5.0 2.0Sources:a WHO (1993)b Cited by Chapman (1996)c Cited by Pescod (1992)Scott et al (2000) noted that environmental accumulation of heavy metals resulting fromwastewater irrigation and sludge is a contentious issue. Khouri et al (1994) indicated thatcadmium (Cd), for example could be present in municipal wastewater at levels that are nottoxic to plants but could build up inside the plant tissue to levels harmful to humans or animals.Similar build up can occur in animals such that heavy metals contained in forage have beenshown to accumulate in cow’s milk, which could lead to hazardous build up in the consumer’sbody. Ensink et al (2002) indicated in a study undertaken in Pakistan that accumulation ofheavy metals proved to be almost negligible, with only increased levels of lead, copper andmanganese, even in the fields that had received wastewater for over 30 years.Apart from containing heavy metals and trace elements, wastewater also contains highconcentrations of dissolved salts (Hussain et al., 2002). Salinity-related impacts of wastewaterirrigation on soil resources can be expressed in economic terms such as (1) potential yield andincome loss; (2) loss of soil productivity; (3) depreciation in market value of land; and (4) cost ofsoil reclamation measures.2.5 Costs and benefits of Using WastewaterIrrigation with wastewater could be an attractive way of disposing wastewater from anenvironmental point of view (Khouri et al., 1994). The combined benefits of reduced treatmentand disposal cost and increased agricultural production may justify investment in an irrigationsystem. Before one can endorse wastewater irrigation as a means of increasing water supplyfor agriculture (Hussain et al., 2002), a thorough analysis must be undertaken from aneconomic perspective as well. The economic effects of wastewater irrigation need to beevaluated not only from the social, economic, and ecological standpoint, but also from thesustainable development perspective. 7
  • 29. 2.6 Agronomic AspectsWastewater has phosphates and nitrates, which are channeled into land as fertilizers(Karpagma, 1999). Mara (1998) discovered that Community based approaches (in LatinAmerica in particular) separate ‘grey’ wastewater (non-faecally contaminated wastewater) from‘black’ wastewater (that is faecally contaminated) so that they can be reused as irrigation waterand fertilizers respectively. The wastewater can be used for unrestricted irrigation of crops suchas lettuce, salads and cucumbers grown for direct human consumption and eaten raw and forrestricted irrigation of crops not intended for direct human consumption such as cotton, sisal,wheat and sunflower (WHO, 1989). Idelovitch and Ringskog (1997) observed that the mostattractive and widespread reuse of effluents is to irrigate agricultural crops, pasture, or naturalvegetation. Other important uses of wastewater include recharge of groundwater, as coolingwater, recreational water, industry construction and dust control, wildlife habitat improvement,aquaculture and municipal non-portable uses such as landscape and golf course irrigation(Hussain et al., 2002; Idelovitch and Ringskog 1997). Reuse of (pre) treated wastewater,especially in agriculture, could considerably contribute to water resources conservation,recycling of nutrients and prevention of surface water pollution. Water quality guidelines arenecessary for wastewater irrigation, but they are rather strict and developing countries cannotafford the expensive treatment (Steenvoorden et al., 2004).Wastewater is used widely in many parts of the world, both in industrialized and developingcountries (Idelovitch and Ringskog, 1997). Increasing sewage or wastewater is seen as aresource, and it is often reused legally and clandestinely (Hussain et al., 2002; Idelovitch andRingskog, 1997). Hussain et al., (2002) observed that wastewater in developed countries istreated prior to its use in irrigation and environmental standards are applied. The wastewater isused for irrigation of fodder, fiber and other seed crops and, to a limited extent for the irrigationof orchards, vineyards, and other crops. Mara (1998) revealed that the water and nutrientcontent in particular can be very useful for agriculture purposes - for example through irrigation.Khouri et al (1994) indicated that wastewater contains nutrients and trace elements necessaryfor plant growth. Five million cubic meters (Mm3) of wastewater contain about 250, 000kg ofphosphorous, and 150, 000kg of potassium. Whether additional fertilizer is required dependson the crop being irrigated. Soil deficiency can be corrected by the trace elements inwastewater and clearly speaking the nutrients in wastewater are beneficial.While wastewater is a resource for productive uses, it can be dangerous to use in an untreatedform. The dangerous practice of direct and indirect use of untreated wastewater is commonpractice in regions like Lima, Mexico City, and Santiago (Mara, 1998; Idelovitch and Ringskog,1997). The practice can be made safe by treating the waste, restricting its use to only onindustrial or fodder crops or applying the waste in specific ways or at certain times (Mara,1998).Moreover, the report by Hussain et al. (2002) revealed that in developing countries, thoughstandards are set, these are not strictly adhered to and wastewater, in its untreated form, iswidely used for agriculture and aquaculture. Idelovitch and Ringskog (1997) have observed intheir report that the most attractive and widespread reuse of effluents is to irrigate agriculturalcrops, pasture, or natural vegetation. Other important uses of wastewater include, recharge ofgroundwater, industry construction and dust control and wildlife habitat improvement (Hussainet al., 2002; Idelovitch and Ringskog, 1997). 8
  • 30. 2.7 Environmental Evaluation of WastewaterGenerally speaking, environmental valuation is used to determine the willingness of people toattach a value of an environmental good such as use of nutrient enriched water in agriculture.There are two types of techniques used in environmental valuation: those relying on revealedpreferences or what humans actually do in the markets; and those relying on statedpreferences or what humans say they would do in a hypothetical market context. Thus both ofthese approaches attempt to evaluate human behavior in economic terms but they differ in thesense that the former is based on actual or observed behavior while the latter is based onpotential or likely behavior (Hussain et al., 2002).2.8 Public Health AspectsThe use of untreated wastewater for irrigation poses a high risk to human health in all agegroups. However, the degree of risk may vary among the various age groups. Untreatedwastewater irrigation leads to relatively higher prevalence of hookworm (Feenstra et al., 2000),and Ascariasis infections among children (Cifuentes et al., 2000; and Habbari et al., 2000). TheDFID-sponsored research in North-east Brazil has shown that bacterial pathogens such asVibrio cholera, Salmonella species and Campylobacter species are present in wastewater(Mara, 1998).With many guidelines dealing with water quality for irrigation purposes, the microbiologicalaspects have always predominated perhaps, because of their immediate human healthconsequences. Chang et al (1996), notes that, few of the irrigation water quality criteria weredeveloped specifically for wastewater irrigation. The public health risks associated withwastewater reuse include increased exposure to infectious diseases, trace organic compounds(Cooper, 1991), and heavy metals. Wastewater contains the full spectrum of enteric pathogensendemic within a community (Scott et al., 2000). Many of these can survive for weeks whendischarged on the land, notwithstanding the presence of infective organisms, however,epidemiological studies have shown that the mere presence of pathogen does not necessarilyincrease human diseases. Of particular interest from a public health perspective are thehelminthes (Ascaris and Trichuris), which have both a relatively long persistence and a smallinfective dose. The risks of intestinal nematodes in untreated wastewater are recognized asimportant, both for consumers and irrigators (Shuval, 1991).According to Rose (1999), the most recent guidelines directing the reuse of wastewater to alevel considered safe to protect human health are those outlined in the Engelberg Standards,later adopted as the WHO of 1989 ‘‘Health Guidelines for the Use of Wastewater in Agricultureand Aquaculture’’. According to Mara and Cairncross (1989) the WHO guidelines outlineacceptable microbial pathogen levels for treated wastewater for reuse in unrestricted andrestricted irrigation. In practice, most developing countries use untreated wastewater foragriculture for a variety of reasons. These include the cost of treatment and the loss of preciousnutrients. However, treatment of wastewater prior to agricultural use is believed to be essential:first from the public health protection point of view and to respect local social and religiousbeliefs (Mara, 2000). According to Hussain et al (2002) in view of these requirements, waterscarcity, dry land farming, hot climatic conditions and the high economic value of fresh waterresources, a great deal of research and development effort has been undertaken particularly inIsrael, for the reuse of wastewater. Furthermore, in the absence of too high a concentration ofwaste from industrial sources, an efficient treatment option for conventional wastewatertreatment is to use primary sedimentation followed by secondary biological treatment usinghigh-rate biological processes. 9
  • 31. Unrestricted irrigation refers to all crops grown for direct human consumption and eaten raw(e.g., lettuce, salads, cucumber) and also the irrigation of sports fields, public parks, hotellawns, and tourist areas. The criteria for unrestricted irrigation, contain the same helminthescriteria for restricted irrigation, in addition to a restriction of no more than a geometric meanconcentration of less than or equal to 1000 faecal coliforms per 100ml treated effluents. Theseguidelines as noted by Mara and Cairncross (1989) have been introduced to protect the healthof consumers who may eat uncooked crops such as vegetables and salads (Table 2.2). Inorder to achieve the microbiological quality, a series of stabilization ponds need to be designed(WHO, 1989). These are a series of ponds, which are used in treating the wastewater before itis discharged into the environment.Restricted irrigation refers to the irrigation of crops not intended for direct human consumptionand there should be no more than one viable human intestinal nematode egg per liter implyinga greater than 99% treatment level (Table 2.2). This guideline has been introduced to protectthe health of field workers and to indirectly protect consumers and grazing cattle (Hussain etal., 2002). Restricted irrigation can be applied to industrial crops (e.g., cotton, sisal, andsunflower, wheat, barley, oats); and fruit trees, fodder crops and pastures (WHO, 1989). Thewastewater retention in stabilization ponds should be 8-10 days or equivalent helminthes andfaecal coliform removal (Hussain et al., 2002). The human intestinal nematodes include,roundworm (Ascaris lumbricoides); hookworm (Ancylostoma duodenale and Necatoramericanus); and whipworm (Trichuris trichiura) Mara (2000).Apart from the biological considerations, nitrates and trace organic chemicals leaching to thegroundwater are considered to pose a potential health risk. However, there is very limiteddocumented evidence that these chemicals have been the cause of human disease (Cooper1991). The leaching of salts, nitrates and microorganisms would be of little concern anyway inareas where groundwater cannot be utilized because of high fluoride, iron, arsenic or saltlevels. In these cases the groundwater has no valuable use attached to it (Hussain et al. 2002).According to Sinkala et al (1996), the storm water collected in storm water drains and joins theShikoswe stream which passes through the Nitrogen Chemicals of Zambia (NCZ) plant andfinally into the Kafue river. The washing from the ammonium plant contain ammonia andnitrates. These are not allowed to go in the storm water drains but go to the balance tank wherethe effluent is neutralized by addition of lime before pumping to the ponds located 2 kilometersout the plant. Some of the results from the study which was conducted in 1996 to 1997 bySinkala et al noted that the concentration of nitrates from NCZ were higher than the ECZ limitof nitrate levels found in the effluents (Appendix XIII).The effluent from Lee Yeast is used by the community between the factory and the KafueRiver, for vegetable growing. The effluent is known to contain low nutrient level except for highChemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD). Sinkala et al (1996)indicated that the effluents from Lee Yeast contain very high total coliforms count per 100mlcompared to ECZ limit. The Total Dissolved Solids (TDS) and Total Solids (TS) were alsohigher than the ECZ limit for effluents and wastewater (Appendix XIV). 10
  • 32. 2.9 Environmental AspectsMara (1977) and United States environmental protection agency (USEPA) (1992) indicated thatone of the negative environmental impacts associated with wastewater use is groundwatercontamination through high concentrations of nitrates, salts and micro-organisms. Faruqui et al.(2002) indicated that environmental issues associated with untreated wastewater reuse arecontamination and clogging of soil particles. Egziabher et al., (1994) noted that environmentalcontamination could be mitigated by treatment of domestic wastewater for unrestricted use.WHO (1989) and Cornish et al. (1990) emphasized that unrestricted irrigation should have nomore than one thousand fecal coliform bacteria per hundred milliliter.Eutrophication of water bodies would be one of the ecological impacts related to nutrient richdrainage water, in the vicinity of wastewater agricultural areas and apart from those related tobuildup of heavy metals and toxic contamination of ecosystem components. Eutrophicationaffects fish species and fish populations and so commercial fishing at such places is affected(income loss). Another consequence of eutrophication is the disappearance of popular fishspecies important for recreational fishing (welfare loss to general public) (Hussain et al., 2002).2.10 Sociocultural AspectsPeri-urban and urban agriculture is understood to be the agricultural activities undertakenwithin the area immediately surrounding the city, where the presence of the city has an impacton land use, property rights and where proximity to the urban market and urban demand drivechange in agricultural production (Hide et al., 2001). Furthermore, urban agriculture is one ofthe several strategies used by the urban and peri-urban dwellers to cope with poverty. It ismainly carried out by, but not restricted to, the urban and peri-urban poor in their efforts to meetthe food needs of their households. The sale of the produce is an integral part of the foodproduction and acts as a source of cash without cutting the household’s food supply. Revenueaccruing from sale of the produce is used for various purposes, such as purchase of householdrequirements, education of children and health expenses.The argument for reuse of wastewater is carried further by Khouri et al (1994) who indicatedthat a physical, natural resources-oriented survey complemented by a socio-economic study ofthe community affected by the reuse project would reveal the need for reuse. However, theacceptance of wastewater reuse and the adoption of practices for its safe implementation willbe influenced by the sociocultural makeup of the people involved (that is the values, beliefs,and customs that are concerned with water supply, sanitation, hygiene and other activitiesrelated to water use). Khouri et al (1994) observed that there are few reconnaissance-typestudies that describe sociocultural aspects of reuse.Furthermore, Hussain et al (2002) indicated that the social concerns about the potential risk ofwastewater irrigation originate from concerns regarding impacts on environmental quality,public health and safety. These concerns may be addressed with appropriate educational andpublic awareness programs. The cost of public education, awareness and demonstrationprogrammes can be used as a choice for the valuation of social impacts of wastewaterirrigation programmes, using awareness and sensitization educational models. 11
  • 33. Table 2.2: Recommended Revised Microbiological Quality Guidelines forWastewater Use in Agriculturea Category Reuse Condition Group exposed Irrigation Intestinal Faecal Wastewater treatment technique nematodesb coliform expect to achieve (arithmetic (geometr required microbiological mean no. of ic mean quality eggs per literc no. per 100 mld A Unrestricted Works, Any ≤ 1f ≤ 103 Well-designed series of irrigation consumers, waste stabilization ponds public (WSP), sequential batch- A1 For fed wastewater storage vegetables and and treatment reservoirs salad crops (WSTR) or equivalent eaten uncooked; treatment (e.g. sports field, conventional secondary public parkse treatment supplemented by either polishing ponds or filtration and disinfections) B Restricted Irrigation B1 Worker (but Spray or ≤1 ≤105 Retention in WSP series Cereal crops, no children <15 sprinkler including one maturation industrial and years), nearby pond or in sequential fodder crops; communities WSTR or equivalent and pasture and treatment (e.g. treesg conventional secondary treatment supplemented by either polishing ponds or filtration) B2 as B1 As for category A Flood/furrow ≤1 ≤103 B3 Workers As for category A including Any ≤0.1 ≤103 children <15 years, nearby communities C Localized None Trickle, drip or N/A N/A Pretreatment as required irrigation bubbler by irrigation technology, category B crops but not less than primary if workers and sedimentation public exposure does not occur Source: WHO (1989) cited by Pescod (1992)Note:a In specific cases, local epidemiological, sociocultural and environmental factors should be taken into account and the guidelines modified accordinglyb Ascaris and Trichuris species, and hookworm; the guideline limit is also intended to protect against risks from parasitic protozoac During the irrigation period/season (if the wastewater is treated in WSP or WSTR which have been designed to achieve these egg numbers, then routine effluent quality monitoring is not required) d During the irrigation period/season (faecal coliform counts should preferably be done weekly, but at least monthly)e A more stringent guideline limit (<200 faecal coliform/100ml) is appropriate for public lawns, such as hotel lawns, with which the public may come into direct contactf This guideline limit can be increased to <1 egg/l if (I) conditions are hot and dry and surface irrigation is not used or (II) if wastewater treatment is supplemented with antihelmintic chemotherapy campaigns in areas of wastewater reuse. 12
  • 34. g In the case of fruit trees, irrigation should cease two weeks before fruit is picked, and no fruit should be picked off the ground. Sprinkler irrigation should not be used.2.11 Irrigation MethodsIrrigation methods can be organized into both means of distributing the raw wastewater to theplants to minimize contamination of the plants, and precautions that the farmers can take toprotect their own health. The main irrigation method currently practiced in the world is the useof watering cans that accentuate the risk of contamination of the plants and farmers. Egziabheret al., (1994) showed that lettuce irrigated with watering cans has higher levels ofcontamination by faecal coliforms and streptococcus than lettuce irrigated by hosing water intothe furrow. Another way of mitigation would be to practice restricted irrigation as recommendedby the WHO. Thus the latter method would be more preferred. In the Zambian context this maybe challenging in that crops such as lettuce and tomatoes are some of the most profitablecrops for peri-urban and urban agriculture. An education programme for farmers, the public andmunicipal officials would be essential to effectively deal with this issue of peri-urban and urbanagriculture.2.12 Policy AspectsThe Zambian National Water Policy of 1994 specifies that water for irrigation should be fit forhuman consumption and not cause soil degradation but enhance high crop yield. Within thebroad objective for agriculture the Ministry of Finance and National Planning (MFNP) (2002)indicates that since the poor rely often on the environment for their livelihood, attacking povertyin rural areas is necessarily improving people’s ability to derive livelihood from naturalresources. In addition, the Zambian Health Policy directs that in order to have a well-nourishedand healthy population that can contribute to national economic development there is need toachieve sustainable food and nutrition security. 13
  • 35. CHAPTER 3: DESCRIPTION OF THE STUDY AREAS3.1 Kafue LagoonThe Kafue lagoon area is located about 50km south of the City of Lusaka (Figure 3.1). Thearea spans a total of over 10 hectares of land under mostly sugar cane cultivation. A map ofthe Kafue Lagoon study area is shown in Figure 3.1. The Kafue Lagoon contains effluents withtoxic chemicals from NCZ (Enviro-line, 1998).The Kafue lagoon receives effluents from LeeYeast, Shikoswe Stream and Nitrogen Chemicals of Zambia. According to ECZ (1994) theNitrogen Chemicals of Zambia (NCZ) opened a sulphuric acid plant in 1983. It producessulphuric acid, which is used in the manufacturing of fertilizers. This process results in theproduction of sulphur dioxide and effluents containing hazardous chemicals. These aredischarged into the drain and it mixes with the sewerage effluents mainly from the ShikosweStream. Shikoswe Stream passes through the NCZ plant and finally discharges into the KafueRiver. During the study period it was observed (based on effluent quality) that production atNCZ and other industries had slowed down or probably stopped.Lee Yeast Company also discharges effluents into the lagoon from its manufacturingprocesses. According to Sinkala et al (1996), Lee Yeast is situated in Kafue town and has threefactories within its premises, namely the Yeast factory, Methylated Spirit Factory and a Bakery.The raw materials for the Yeast factory are the molasses (carbon sources), urea, Di-ammoniumphosphates and Magnesium sulphate, Zinc Sulphate, Chlorine and Ammonium Sulphate. Theraw materials are mixed in various proportions in three vessels. The yeast pulp is separatedfrom the liquid and this forms the effluents discharged by the Yeast factory. Other industriesnearby include Kafue Textiles, Kafue Chemicals and Bata Tannery. The industries provideemployment for the population of Kafue.Most of the peasant farmers in the study area come from Zambia Compound and SoloboniCompound which also form the peri-urban part of Kafue District. Few others came from Kafuetown and Kafue Estate. In 1996 there were about 320 farming households in the study areaaccording to Sinkala et al (1996). This number could have increased over the years due toslowed production or complete stoppage of production in the nearby industries resulting inmass retrenchment of workers. The victims, especially the unskilled, resorted to urbanagriculture as an alternative livelihood source. Retired workers who do not wish to go to thevillage also venture into farming in the area. The total population of Kafue Ward is 9,360according to the 2000 Census. Of this figure 50.49% are male while 49.51% are female. Thenumber of households is 1760. Since the population of Soloboni and Zambia compounds (andalso of the prei-urban community where majority of farmers in the study area come from) is notisolated, the exact population of the study area can only be obtained from an independentenumeration.The social organization in the area is such that the per-urban communities are regulated by thedistrict council. However, in the Kafue Lagoon Area, political parties play a major role incommunity management, where they even form a de facto structure for accessing land. Accessto clean drinking water and good sanitation is still a big problem in the study area. Since pipedwater does not carter for the larger population in the area, people alternatively fetch drinkingwater from the Kafue River and hand dug wells. Over half of the people in the area do not havetoilets and many just go to the bush to defecate. The study by Sinkala et al (1996) found 80%of respondents around the Kafue River (including the Kafue Lagoon Area, fishing camps andrural areas) did not use any toilets whatsoever. According to sources at the health centres in 14
  • 36. the area, the most prevalent disease is malaria, followed by respiratory tract infections anddiarrhoeal diseases.The commonest economic activities in the peri-urban community are petty trading andcultivation of vegetables and sugar cane using domestic and industrial effluents. For manypeasant farmers in the area, urban agriculture is the main source of income for most part of theyear. Individual consumers and traders purchase the crops from Kafue Estate and Kafue townrespectively. A few individual consumers go into the Lagoons to purchase the crops and theseinclude: sugar cane, cabbage, rape, onion, cassava, and tomato.3.1.1 Site 1 (Shikoswe Stream)The site is located (latitude 15o45’23.5”, longitude 028o09’40.2”) on the effluent canal passingthrough the Nitrogen Chemicals of Zambia before it enters the fields, where the water isdiverted for irrigation through a series of smaller earth canals. The effluent from NCZ mixeswith domestic sewage.3.1.2 Site 2 (Near Lee Yeast, LY)This site is located (latitude 15o45’21.2”, longitude 028o09’36.6”) before the fields and on theeffluent canal coming from Lee Yeast factory, which produces yeast. Because of the deepbrown colour of the water, it is usually mixed with the water coming from the NitrogenChemicals of Zambia before conveying it to the fields.3.1.3 Site 3 (Nitrogen Chemicals of Zambia, NCZ)This site is located (latitude 15o45’28.0”, longitude 028o09’52.5”) on the eastern part of theShikoswe stream below the footbridge. The NCZ effluents are discharged into this canal, whichpasses through the vegetable and sugar cane fields. This is the site where ECZ also conducttheir quality testing of the effluents being discharged by NCZ from the Plant. 15
  • 37. 16
  • 38. 3.2 Ngwerere River AreaThe Ngwerere is a small river whose origin is in the city of Lusaka and it stretches over adistance of approximately 30 kilometers as shown in Figure 3.2. The stream from of theUniversity of Zambia Lusaka Campus, near Goma Lakes, feed the Ngwererere stream. Thestreams making the Ngwerere River have their sources within the town area. One, whose originis not well known, emerges opposite ZESCO (Zambia Electricity Supply Corporation) on thenorthern side of the Great East Road and flows in the north-eastern direction through ThornPark residential area. This is called Ngwerere 1 in the report by Tembo et al (1997) and thecolour of the water is usually grey. Another main arm (drainage canal) comes from the Farviewarea, crosses the Great East Road around Northmead and passes between GardenCompound and residential areas of Northmead and Olympia before it is joined by the effluentstream from Manchinchi Wastewater Treatment Plant (WWTP) near Roma Township. This isalso conveniently called Ngwerere 2. The two streams (Ngwerere 1 and 2) join at about 500mdownstream of Kabeleka Road Bridge to form the Ngwerere River proper between GardenCompound and Roma Township. At this point the colour of the water is green mainly due toalgae in sewage water.In this rural area, a lot of farming activities are taking place and thus a lot of water is drawnfrom the Ngwerere River for irrigation.The Ngwerere River discharges into the Chongwe River, which is a tributary of the ZambeziRiver. Wastewater (nutrient enriched water) in the Ngwerere River is utilized for irrigating avariety of crops/or vegetables within the catchment by both large-scale and small-scale (mainlypeasant) farmers. Crops are watered in the dry and, to some extent in some portions of thecatchment, in the wet season using the pre-treated wastewater. The crops grown includecabbages, pumpkins, sweet potato, lettuce, rape, onion, spinach, tomato, maize and sugarcane. The vegetables and sugar canes are sold to individual consumers and vegetable tradersat the public markets (Soweto Market and others) in Lusaka.As in the case of the Kafue Lagoon Area, the exact population of Ngwerere River catchment iscan only be obtained from an independent enumeration. However, according to the 2000Census, the population of Ngwerere Ward, which forms a large part of the Ngwerere RiverCatchment, is 51,218. 50.77% of this population is male while 49.23% is female. There are9826 households. Estimating the population of Ngwerere River Catchment using the populationdensity of 63.5 for Lusaka Province, gives the figure 17,000. This might be a good estimateconsidering that part of the Ngwerere Ward is outside the river catchment under considerationand that part of the river catchment actually lies in Chongwe District.The main economic activities include wage employment and trading in the urban part of thecatchment and petty trading, vegetable/crop growing and large-scale commercial farming in theperi-urban and rural parts of the catchment. Commercial farmers grow flowers, maize, wheat,peas, beans, paprika and other high value crops including vegetables and horticultural plants.Some of the peasant farmers and other residents are employed on these farms for wageincome.There are organizations and institutions involved in the management of the local communityand its activities. These include the Zambia National Service, rural health centres (RHCs),schools, political groups and the River Catchment Committee looking at the water resourcesand agricultural activities. These organizations and in some cases individuals own and rent outland to peasant farmers. 17
  • 39. 3.2.1 Site 1 (Near Garden Site 3 ponds, N1)This site is located between Garden compound and Roma Township (Latitude 15o22’09.1”,Longitude 028o18’07.6”). It is about 20m downstream of the confluence of the two main arms ofthe Ngwerere River one originating from the town area (visible opposite ZESCO Ltd) andanother from the Northmead/Olympia residential area. An effluent stream from Garden Site 3maturation ponds and another from N’gombe/Kalundu residential area join the latter before theconfluence of the two arms (near Mazyopa Compound and Roma Township). This captures thelargest part of the total point-source pollution in Ngwerere River leaving the City of Lusaka.Furthermore this site was also used by the study of Tembo et al (1997) hence it would give areasonable comparison, about eight years later.3.2.2 Site 2 (At Ngwerere Estate Weir, N2)This station is just upstream of the Ngwerere Estate Weir (about 500m, Latitude 15o19’,Longitude 028o19’). At this point, the river has passed through several gardening communitiesbut the water quality is expected to improve more than at Site 1 which is 5 km away. One mainadvantage of Site 2 is the proximity to the permanent gauging station belonging to theDepartment of Water Affairs, which would enable the estimation of river flow at this point.3.2.3 Site 3 (Below Kasisi Dam, N3)This site was located after the Kasisi Mission dam about 15km from Site 2. This represents theriver before the confluence with the Chongwe River and is the most accessible in the rural areadrained by the river which is not influenced by the backflow effect due to the Chongwe-Ngwerere confluence. By this time the river has undergone substantial self-purification and it isexpected that the vegetables grown in this area will have less contamination than those grownin the upper reaches. 18
  • 40. 19
  • 41. CHAPTER 4: METHODOLOGYThe methods used during the study were both qualitative and quantitative in the generation ofinformation as well as documenting the findings.4.1 Secondary Data collectionVarious documents were reviewed on the work done on utilization of wastewater or nutrientenriched water in Zambia and other parts of the world. Various legislative articles frominstitutions such as the Environmental Council of Zambia, department of Water Affairs andMinistry of Health were also reviewed. Other documents such as the WHO guidelines and ECZwastewater Standards on the safe use of water for irrigation were also reviewed.4.2 Primary Data Collection4.2.1 Field InterviewsThe population in both study areas was sampled using the grid method. A reconnaissancesurvey was conducted at both study areas to test the questionnaire and establish the samplesize.Since the peasant farmers in the Kafue Lagoon Area were clustered, fewer respondents wereneeded than in the Ngwerere Area where they were scattered. In a clustered set up theresponses would not vary significantly as in a scattered arrangement. For instance the areacovered in Ngwerere spanned a distance of over 20 kilometers while at Kafue Lagoon area thearea covered was within the radius of 5 kilometers. Therefore the sampling used within the gridareas to come up with the number of respondents was judgmental technique taking intoconsideration the prevailing field conditions and available resources. Originally 50 respondentswere interviewed in the Ngwerere area and 30 respondents in Kafue Lagoon area, but in theanalysis of the questionnaires, 8 from the Ngwerere area were rejected.Information was gathered by using a combination of observations, field surveys and structuredinterviews with selected growers. Surveys were carried out to ascertain the types of cropsgrown within the Ngwerere catchment and at Kafue Lagoons. Questionnaires wereadministered in the field to gather information on how the communities or peasant farmers’value enriched wastewater in irrigation. The sample size used was 30 respondents from KafueLagoon and 50 respondents from the Ngwerere Area.The individual farmer interview covered personal and household information, household socio-economic status, and crop marketing, healthy aspects, cropping pattern, plot characteristics,water management and farmer’s conception of constraint. At the peasant farmer’s levelinformation was collected on the history of irrigated vegetable farming, the level of interestshown by the farming individuals, gender, irrigated vegetables grown, common methods ofconveying water and sources of water. The questionnaire is reproduced in Annex I and thelocation of the survey sites are shown in Figures 3.1 and 3.2. The sample size was determinedafter conducting a reconnaissance and testing the questionnaires within the two study areas.The average plot size for the surveyed farms (small-scale peasant farmers) in Ngwerere area is0.25 ha and ranges from 0.1 ha to 0.5 ha whilst in Kafue Lagoon is 1.2 ha and ranges from0.25 ha to 2 ha respectively. Actual plot measurements were not taken due to time factor andthe study team did not have the equipment such as measuring tape or surveyor’s band. 20
  • 42. Farmers were asked to estimate their plot areas during the interviews although the interviewercould also estimate sometimes by counting steps. The number of crops grown on each farmvaried from farmer to farmer and from season to season. Table 5.3 below identifies the cropsgrown by farmers in Ngwerere and Kafue Lagoon areas. Each farmer grows an average of 5crops. However, most farmers seem to concentrate on one or two crops. In the study areas, thepeasant farmers irrigate high-value crops, which are also shown in the table below.A case study was used in collecting data aimed at achieving the specific objectives. Accordingto Young, a case study is a method of exploring and analysing the life of a social unit, be it aperson, a family, an institution, cultural group or even an entire community (Ghoshi, 1992).The sampling technique used before administering the questionnaires was a random samplingby a Grid System technique (Ghoshi, 1992) was used to determine the sample size. The GridSystem method involves putting a screen with squares on a study map and the areas fallingwithin selected squares are selected samples.4.2.2 Computation of the Quantity of WastewaterThe quantity of wastewater in the Ngwerere stream was computed by analyzing thehydrological data from the Ngwerere Hydrological Station of the Department of Water Affairs.Hydata and Arida software were used to compute the total surface run-off and then separatingthe base-flow from the total surface runoff in cubic meters. This was undertaken to know theamount of wastewater in the Ngwerere River and the contribution of the groundwater to thesurface run-off passing through the hydrological station for the Department of Water Affairs(DWA). The Estate Weir at Ngwerere River station was selected to compute the quantity ofwastewater because it has historical hydrological data which can be used for computationusing various software.4.2.3 Plant samplingIn the Ngwerere River Area, the crop samples were collected in Chamba Valley near NgwerereEstate Weir. Only the leaves of rape were collected and taken to Food Science Laboratory atthe University of Zambia in the School of Agriculture.In the Kafue Lagoon Areas three samples of crops were collected and taken for analysis ofheavy metal concentration at the University of Zambia. The leaves of rape (medium and large)sampled were collected near the Lee Yeast effluent canal as shown in Plat 5.5. One sample ofthe sugar cane stock was collected because large quantities of sugar canes sold in Lusaka,Chirundu and other areas come from the Kafue lagoon Areas in Kafue. The analysis for heavymetals in crops/or vegetables was only for exploratory purposes.4.3.4 Sampling of Water, Sediments and PlantsA total of eight (8) sampling campaigns at each site in Ngwerere and four (4) at each site inKafue were carried out between 6th July 2004 and 20thAugust 2004. In total two (2) campaignsin Ngwerere involved one (1) duplicate sample for each site and in Kafue two (2) campaignsincluded one (1) duplicate sample at three (3) sites 21
  • 43. 4.3.4.1 Ngwerere Catchment AreaThe full stretch of the Ngwerere River was surveyed to select three points for sampling (water,sediment, plants) and testing over a period of 2 months. The three sites were chosen accordingto the following criteria:1. Accessibility2. Representativeness of the site with respect to project objectives3. Ease of sampling and on-site tests4. Sites that would enable transportation of samples to the laboratory within seven (7) hours5. The site should be at or near a point where reliable flow measurement could be measured or estimatedBeing a narrow channeled stream, the Ngwerere was assumed to be completely mixed over itsdepth and width. This was further confirmed by taking conductivity measurements along thecross-section and at various depths. The conductivity did not vary significantly for the purposesof this study. (However, this was only done for conductivity and so there may still be need toconfirm with another parameter). A grab water sample collected at about 5cm depth in themiddle of the river channel was considered representative enough.The water samples were obtained by wading into the river, immersing a sample bottle about5cm below the water surface and collecting the water. Because the water was clear in mostinstances, the bottle could be held against the flow without catching any floating debris. Forchemical analysis a polythene bottle (1000ml) was used while for heavy metals a 500ml bottlewith 2ml nitric acid inside was used. A sterilized glass bottle was used for microbiologicalsampling. The bottles were then kept in a cool box packed with ice blocks. Another 1000ml-polythene bottle was used to store bottom sediment, which was scooped from the riverbedwhere it had accumulated. This was stored separate from the water samples.Care was taken to avoid cross-contamination by correctly labeling all the bottles and recordingin a field record book, and starting sampling with the least polluted site (start with Site3, thenSite2 and finally Site1). Site1, Site2 and Site3 are later designated as N1, N2 and N3,respectively for convenient identification.In-situ water tests were carried out using the Horiba Water Checker U-10 model. It was used tomeasure water temperature, pH, conductivity and salinity. These parameters are reliablymeasured in-situ due to their tendency to change with slight changes in surroundingtemperature and ionic activity4.3.4.2 Kafue Lagoon AreasThe land was surveyed to select three points for sampling (water, sediment, and plants) andtesting over a period of 2 months. The sites were selected to cover the effluent canals whichare used by farmers in the Lagoon areas. The effluent canals were the Shikoswe stream, Leeyeast effluent canal and Nitrogen Chemicals of Zambia effluent canal. The sites were chosenaccording to the following criteria:1. Accessibility2. Representativeness of the site with respect to project objectives3. Ease of sampling and on-site tests4. Sites that would enable transportation of samples to the laboratory within seven (7) hours 22
  • 44. 4.4 Measurements of the Parameters4.4.1 Laboratory AnalysisThe samples were analyzed at the Environmental Engineering laboratory of School ofEngineering at the University of Zambia. The samples were transported to the laboratory within7 hours of sampling. This was to ensure quality control of the samples. Some parameters wereimmediately analyzed whereas part of the samples had to be frozen or incubated before theparameters were analyzed such as COD. The parameters are shown in Table 4.1 including themethods of analysisTable 4.1: Parameters sampled and methods used for analysis Parameter Method Physical pH Electrometric Conductivity Electrometric Salinity Electrometric Total Suspended Solids (TSS) Gravimetric Chemical Bi-Carbonates Titrimetric Ammonia Nessler Spectrophotometric Sulphates Turbidimetric Nitrates Electrometric Total Phosphates Vanamolybdic Spectrophotometric Chemical Oxygen Demand Dichromate Spectrophotometric Nitrogen Kjeldahl Destruction Metals Cadmium Atomic absorption Copper Atomic absorption Cobalt Atomic absorption Zinc Atomic absorption Iron Phenanthroline Spectrophotometric Sodium Flame Photometric Calcium Titrimetric Magnesium Titrimetric Microbiological Biological Oxygen Demand Modified Winkler Faecal Coliforms Membrane Filtration Faecal Streptococci Membrane Filtration E. Coli Membrane Filtration4.4 Data AnalysisGenerally, data was analyzed using MS Excel spreadsheet, Arid Region Drought Analysis(ARIDA), Hydrological Data Analysis (Hydata), graphs and tables.The information obtained from the field questionnaire interviews were entered into an MS Excelspreadsheet, cleaned and analyzed using charts contained in the programme. The sameapplied to field and laboratory measurements of water, plant and sediment samples. 23
  • 45. The water quantity data for Ngwerere Estate Weir was obtained from Department of WaterAffairs and analyzed using recommended software, Hydata and ARIDA.Water, plant and sediment quality data was also analyzed using MS Excel spreadsheet. Forquality control, duplicates were obtained at selected stations and sampling campaigns. Thishelped to check the reliability of the results. In addition trends in the data sets were used tocheck for reliability of the data. The percentage relative error was used to check for reliabilityaccording to the following formaula:% relative error = {result (sample–duplicate) /average result (sample +duplicate)} * 100If the percentage difference between the duplicate and the sample was more than 50%, theresult was not acceptable.4.4.1 Analysis of Quality controlFor Kafue Lagoon the results from the duplicates for most of the water quality parameters wereacceptable (i.e., 85% or 35 out of 41 test results) according to the relative error (%) formula.Only iron for NCZ samples, TSS and total phosphate results were doubtful (see ANNEX XVI).Overall the samples collected were representative enough of the sites along the streams buterrors could have occurred in the analytical procedures for total phosphate and iron at thelaboratory. While the same holds for TSS, there is also a possibility that error occurred incollecting the samples, given the variable nature of suspended matter. Similarly for theNgwerere results, TSS was suspect for all samples from the three locations in the 4th August2004 campaign and so the results were rejected. Out of 42 test results, 30 (or 71%) wereacceptable in the 4th August 2004 campaign and 8 (or 81%) were acceptable in the 5th August2004 campaign (see Appendix XVII). Taking the total number of test results (82) for Ngwerere,64 (or 76%) were acceptable.Overall, the fewer test results of TSS, BOD, COD, total phosphate, faecal coliforms, faecalstreptococci and E. coli that were found to be unreliable were due to most likely error insampling and analytical procedure with respect to each parameter. However, the data was stilluseful to the overall analysis by using average values instead of individual values. Moreover,large differences between duplicates were common in many surveys, especially those involvingmicrobiological parameters and so the rejected or doubtful data were not completely discarded.Statistical testApart from the mean and standard deviation used to present and analyse the data, the studentor t-test and confidence limits were used to further analyse the data, confirm assumptions inthe study and to place a level of confidence on the data obtained. The 95% confidence limitwas used in the tests. The Null Hypothesis (NH) was used to assume no significant differencebetween the means of two data sets in a two-tailed t-test. See Annex XVIII for details of the t-test.4.5 Limitations of the studyData Gap - There was no consistent baseline data on river water qualityFinances - All necessary water quality parameters could not be undertaken due to financialconstraints. Given the required frequency of water quality sampling and laboratory testing thetotal distance which was to be covered exceeded the budgeted for total distance. 24
  • 46. The time Factor – The time given to submit the progress report and later on the final draftreport dictated the rate of implementation of planned activities. It did not coincide with the timerequired for data analysis e.g. the laboratory analysis took longer than expected. Hence thesampling interval was intense (3 samples per week in Ngwerere and 1 sample per week inKafue Lagoon) and thus affected the carrying out of other activities such as questionnaireadministering and report compilation within the study period. Time was also needed to link withother institutions such as health centres (e.g., Chipata Health Centre), cooperatives and othercommunity based organizations within the framework of the study for obtaining secondary data.Seasonal trends could not be captured due to the short period of sampling.Sampling – The population was sampled using the grid method. Randomization was notpossible in the framework of this study because of time, accessibility of farms/gardens anddistance constraints. The period the samples were collected from the field and the time theresults were made available to the research team for further analysis was long. This affectedthe compilation and interpretation of the data in that little time remained for data analysis.Control area – there was no control area for the study to compare the results from the studyareas. 25
  • 47. CHAPTER 5: RESULTS AND DISCUSSION5.1 Field interviews5.1.1 Demographic information on households using the wastewaterA summary of general information of respondents is given in Tables 5.1Table 5.1: Gender and age of respondent regarding use of wastewater for irrigation Gender Age Males % Females % Mean Minimum Maximum Ngwerere Area 34 81 8 19 30 15 45 Kafue Lagoon 12 40 18 60 35 26 45 All 46 26It was found that 60% of the farmers producing irrigated crops in Kafue Lagoon area werewomen and only 40% were men. Ngwerere area presented the opposite scenario with 81% ofthe farmers being men and only 19% women. There were fewer women than men in theNgwerere area mainly because the crop fields were far (generally over 5 kilometers) from theresidential areas and it was not safe for the women to walk by themselves through the bush tothe crop fields. At Kafue Lagoon area there were more women than men because the houseswere nearby (within a kilometer) and it was relatively safe as people could easily see oneanother as they worked on their fields. In addition, most of the female respondents werewidows (Annex II). Therefore, the chance of finding female respondents at Kafue Lagoon washigher than at Ngwerere.5.1.2 Kafue Lagoon AreaIt discovered that the educational levels of the respondents varied. 26% didn’t have any formaleducation and 74% had (17% had secondary level education and 57% had gone up to primarylevel).It was found out that the main occupation of peasant farmers in the Lagoon was gardeningwhilst the second occupation included various activities such as selling of charcoal, farming,piece work and keeping of livestock (more information in Annex I).The main and alternative sources of income for the peasant farmers in Kafue Lagoon Areaswere selling of vegetables, sugar canes and gardening.5.1.3 Ngwerere River AreaThe education levels of the respondents varied - 14% had no formal education and 86% hadformal education (31% - secondary level education, 53% - up to primary level and 2% - up totertiary level). Approximately 19% of the farmers interviewed were women and 81% are men inthe Ngwerere area.The main occupations of peasant farmers in the Ngwerere River area were gardening,producing and selling of vegetables, maize growing and farming. 26
  • 48. The main sources of income for the peasant farmers in Ngwerere River area were selling ofvegetables, and gardening. The alternative sources of income were retirement package(pension money), rental from houses, business and piece of work, selling of pesticides, sellingof vegetables and gardening (more information in Annex I).5.1.4 Agricultural PracticeThe general agricultural practices in the study areas are shown in Table 5.2. Land tenure wasleasehold, farmer’s own land, Zambia National Services land or communal land in theNgwerere area. In the Kafue Lagoon area land tenure was freehold. The cropping pattern wascomposed of vegetables, maize and sugar cane.In the Ngwerere area where the land was being rented, the ability of the peasant farmers togrow more crops was limited by the size of land under cultivation which in turn depended onthe amount of money for they could pay for rent. The amount of money paid per unit of landand the unit of land itself varied e.g. about one lima was rented between K20, 000.00 – K60,000.00 per six months. Therefore, the peasant farmers who rented plots could only grow highvalue crops such as rape and chomoliya.In the Kafue Lagoon area the land tenure was freehold but the peasant farmers were chargedK10, 000.00 per year by a local organization (Chilumba). The fields were generally bigger thanat Ngwerere. Freehold land tenure determined the cropping pattern in the Kafue Lagoon area.Table 5.2: General agricultural practices in the study areasObservation Items Study Site Ngwerere River Area Kafue Lagoon Area1. Land tenure status -Farmers own land -Freehold -Zambia National Service -Communal land -Leasehold2. General land layout and land -House erected on upper portion -Freeholduse for owners use -Discharge of effluent Lagoon -land is rented -Land belongs to ZNS3. Sources of irrigation water -Permanent stream running within -Effluent canals from Lee Yeast, NCZ the catchment effluent canal and Shikoswe stream -Stream pools -Shallow wells4. Methods of irrigation -Manually using buckets and tins -Manually using buckets and tins -Use engine pump and hose pipes -Furrows and canals5. Cropping pattern -Vegetables and maize -Vegetables, maize and sugar cane5.1.5 Crop choiceThe choice of crops to be grown in the study areas varied. In the Ngwerere area a variety ofcrops were grown which are: cabbage, tomato, sweet potatoes, Chinese cabbage, lettuce,onion, rape, carrots, egg plants and spinach. However, in the Kafue Lagoon area, the mostfrequently grown crops are tomatoes, Chinese cabbage, rape, pumpkin leaves, sugar cane andmupilu. It was ascertained that the most frequently grown crops in both areas were chinesecabbage, rape and mupilu. These three crops are high value crops in the urban areas ofLusaka and Kafue. The various crops grown are indicated in table 5.3. Plates 5.1 and 5.2shows the crop which is mostly grown by farmers in the Ngwerere River Area. 27
  • 49. Plate 5.1: A plot of Rape in Ngwerere River Area near Ngwerere Estate Weir Plate 5.2: Plots of Rape in Chamba Valley near the Ngwerere River 28
  • 50. Table 5.3: General crop selection by farmers in the two study areasCrop Ngwerere River Area Kafue Lagoon AreasCabbage xxx xTomato xxx xxSweet potato leaves xxx -Chinese cabbage xxx xxxLettuce xxx -Onion xxxRape xxx xxxCarrot xxx -Green pepper xx -Nchembele xxx -Potatoes xxx -Pumpkin leaves x xxxOkra x -Chikolowa x -Cassava x xBananas - xBeans x xEgg plant xxx -Sugar cane - xxxMaize x xWhite logo xx xMupilu xxx xxxSpinach xxx -Note:x Least frequently grownxx Moderately grownxxx Most frequently grown5.1.6 Water Management and SourcesFigure 5.1 shows the different water sources used for irrigation in the Kafue Lagoon. 32% ofthe respondents relied on shallow dug out wells. 14% of the respondents utilized the canal,which carried wastewater from Lee Yeast whilst 29% of the respondents used effluents comingfrom the Nitrogen Chemicals of Zambia (NCZ).The major water source for irrigation was the Ngwerere River and the most common method ofapplying water was to collect from the stream or river, and to apply it to the crops using watercans or buckets (10 to 20 litre containers). Even though this was labour intensive method,some farmers were able to apply nearly to the entire crop water requirement. 29
  • 51. Water Sources Used for Irrigation Shallow dug Canal from Lee out Yeast 14% 32% NCZ Canal & Shikoswe Stream 10% Guter+NCZ & Gutter Lee Yeast 5% 10% NCZ Canal 29% Figure 5.1: Water sources used for irrigating crops in Kafue Lagoon5.1.7 Conveyance of water and field applicationFigure 5.2 show that 88% of the respondents conveyed irrigation water to crops manually usingbuckets. The distance that farmers conveyed irrigation water from the sources to the fieldvaried greatly between individual farms. The water was conveyed manually using buckets of 10to 20 litres. The frequency of irrigating varied according to the crops, its stage of developmentand the weather but was also influenced by groundwater seepage from the furrows. Manually using a Underground water bucket & small 4% canals 4% Flood Irrigation Manually using a 4% bucket 88% Figure 5.2: Conveyance of water for irrigation in Kafue Lagoon AreaIt was found that 93% of the farmers interviewed in the Ngwerere River area (figure 5.3)irrigated their crops manually using buckets or watering cans and only 7% used pumps (treadlepumps and engine pumps) and hose pipes to convey the water to the fields of crops. 30
  • 52. Pump Manually using using engine bucket/tin 7% 93% Figure 5.3: Conveyance of water for irrigation in Ngwerere River5.1.8 Crop yields and earnings from crop salesThe yield of vegetables varied from one respondent to the other and the figures are based onthe data obtained from the farmers through interviews. Secondary data to cross check thefindings from the field was not obtained from the Ministry of Agriculture and Cooperatives andother sources. As such the incomes of the farmers are indicative figures. A further analysis ofincome and expenditure pattern at household level could be a subject of another research.5.1.9 Crop marketing by farmers in the Ngwerere and Kafue Lagoon areasComparative data collected from the two study areas from farmers interviewed are summarizedin the table below.Table 5.4: Comparative methods of marketing crops practiced in Ngwerere and KafueLagoon areaMechanism % of farmer Ngwerere Area (50 Kafue Lagoon (30 farmers) farmers)Take produce to market 74 67Consumers buy from field 12 17Traders buy from field 14 13Others 5 3 100% 100%5.1.10 Crop marketing by the farmers in the Ngwerere AreaThe single most common means of marketing the produce was for growers to market and saletheir produce individually at markets: Soweto, Town Centre, Kabanana, Chipata Compound,Ngombe, Katabalala, Chaisa, Garden, and Kaunda Square markets which is at 69%. 5% of thefarmers sold their produce to Fresh Mark in Lusaka town. Traders (14%) from nearbycompound buy the crops, which they later sold in different parts of Lusaka. Individualconsumers also bought crops from the Ngwerere river areas. It discovered that 83% of thefarmers marketed their crops individually, 12% as a formal group, 3% as traders whopurchased the produce from the farmers, which they later resold. The results are showngraphically in figure 5.4. 31
  • 53. Consumers buy Take produce to from field 12% market 69% Traders buy from field 14% Others (Fresh Mark) 5% Figure 5.4: Market channels for crops grown in the Ngwerere River Area5.1.11 Crop marketing by farmers in the Kafue Lagoon areaAll the farmers interviewed from the Kafue Lagoon area marketed and sold theircrops/vegetables individually. The crops were being sold in different parts of Kafue and Lusakaincluding Chirundu. The following are the areas were the produce are sold: Kalukungu market,Kafue Estates market, Zambia Compound Market and Solloboni Market, Lusaka urban andLusaka rural and Chirundu. Some of the traders from Lusaka, Chilanga and Chirundupurchased the produce from the growers and later resold in Lusaka or Chirundu. Someindividual farmers marketed their own crop at the markets in Kafue Town and individual tradersalso bought the produce from the growers at their fields.It was discovered that 13% of the farmers sold their crops/vegetables directly to traders whovisited their field crops. 17% of the farmers sold their crops to the local consumers while 67%of the farmers sold their crops at market places. Take produce to market 67% Consumers buy from field Others 17% Traders buy 3% from field 13% Figure 5.5: Mechanism in Marketing of Produce by Farmers in Kafue Lagoon 32
  • 54. 5.1.12 Earnings from sales of crops in Kafue Lagoon AreasThe income realized from the sale of different crops varied depending on the type of crop,number of customers and season (with respect to price). For example it was reported that rapecould be harvested seven times before another crop is planted and this on average means thatrape can be planted twice in a year. At each pick or harvest a 50 Kg sack of vegetables (not50kg of vegetables) was sold between K 4, 000 and K 10, 000. Taking an average selling priceof K7000 per bag of rape the total income realized was K140, 000.00 per year. However, morebags per pick could be sold (e.g. three 50 kg sacks of rape per day sold between K8, 000 toK10, 000 each) and furthermore, the same farmer could sell a handful of rape at K500.00 perbunch. The farmer can have more than one crop e.g. rape and tomato. One box of tomatoesfetched between K18, 000 to K20, 000 each. The average income that can be estimated is onlyindicative for a specific crop. Further information on yields and prices are indicated in table 5.5and 5.6.Table 5.5: General crop growing season, acreage, yield, unit and unit price in the KafueLagoon area MonthsCrop S O N D J F M A M J J A Area (acres) Yield Unit Price per unit (kwacha)Cabbage 50kg sack 20000-30000Tomato 0.25-1.5 acre 2-10 boxes 1 box 5000-25000Mupilu 1 acre - 0.25 ha 2 - 8 bags 50 kg sack 15000-40000Chinese cabbage 0.25 acres - 0.5 acre 5-9 bags 50 kg sack 7000Onion 1 acre 1 bag 50 kg 15000Rape 0.25 acre - 0.25 ha 1-2 bags 25-50kg 5000-35000 sackPumpkin leaves 0.25 acre 6 bags 50 kg sack 5000-10000Chikolowa 50 kg sack 18000CassavaBananas Per bunch 2000GuavaBeans Per bundle 500Sugar cane 1 acre 50 bundles Portion 8000 per portionMaize 1 acre 200-500 per 300 per cob cobTable 5.6: Farmers’ total income in Kafue Lagoon and Ngwerere River Areas Amounts in Zambian Kwacha Per plot Per day Per week Per year Kafue Lagoon Areas 100, 000 8 000 - 60 000 8 000 – 500 000 800 000-1, 000, 000 Ngwerere river Area K30 000 – 40 000 K5, 000-K80, 000 K15 000 – K500 000 200 000 – 2 400 000 33
  • 55. 5.1.13 Earnings from sales of crops in Ngwerere River AreaSimilar analysis for Ngwerere River Areas as for Kafue Lagoon Areas (Section 5.1.12). Theincome realized by a farmer is higher than the one in the Lagoons. The average income realizeper month from selling of vegetables by farmers was K200, 000 because they had a widermarket coverage and relatively shorter distances to markets and higher demand for the crops.For instance Kafue Lagoon area, sugar cane was transported to far away markets such asLusaka and Chirundu. Further information on yields and prices are indicated in Tables 5.6 and5.7.Table 5.7: General crop growing season, acreage, yield, unit and unit price in theNgwerere areaCrop Months S O N D J F M A M J J A Area (acres) Yield Unit Price per unit (Kwacha)Cabbage 50kg sack 20000-30000 per head 1000Tomato 1 acre 2-6 boxes 1 box 10000-70000Spinach 0.25 ha 3 bags 50-75kg 40000-60000Mupilu 1 acre - 0.25 ha 2 - 8 bags 50 kg sack 15000-40000Nchembele 1 acre - 0.25 ha 4-6 bags 50 kg sack 15000-30000Chinese cabbage 0.25 acres - 0.5 acre 5-9 bags 50 kg sack 30000Lettuce 0.25 acres 10 bags 50 kg sack 20000Lettuce per head 500Onion 0.5 ha 10kg porch 35000Onion 1 acre 1 bag 50 kg 15000Rape 0.25 acre - 0.25 ha 6-12 bags 50kg sack 15000-60000Carrot 0.25 -0.5 acre 5-9 bags 300 kg 2000-2500/kgGreen pepper per kg 1500Potatoes 4 bags 50 kg 48000Pumpkin leaves 15meters*20meters 8*50kg 50 kg sack 15000-35000 bagsOkra 1 acre 1 bag 50 kg sack 7000Maize 1 acre 10 cobs @ 3000- K35005.1.14 Public health issuesTable 5.8 below shows clinical data from Kasis Rural Health Centre. It was found that theprevalent diseases in the study area were malaria, bilharzias and diarrhoea. For the Ngwererearea, secondary data obtained at Kasisi Rural Health Centre to confirmed the findings. Table5.8 indicates the figures of reported cases of water-borne diseases associated with the riverwater including all age groups from the year 2000 up to June 2004. Malaria toped the list as themost prevalent, followed by diarrhoea, bilharzias and dysentery. Considering the totalpopulation of the Kasisi sub-catchment (11,450), the disease burden was relatively high, 34
  • 56. especially for the current year, which by June 2004 (half way) had malarial cases alreadyhigher than the total cases of each of the previous years. For diarrhoea, the cases were higherthan half of the average cases for previous years. The same applies to this year’s (2004)bilharzias and dysentery cases when compared to cases for last year (2003). Malaria andbilharzias are directly related to the Ngwerere river water. The two diseases are closelyassociated with damming of watercourses within the catchment up to Kasisi Mission and beforeits confluence with the Chongwe River the Ngwerere River has several dams. This reduced thevelocity of the river, resulting in sedimentation of suspended materials including bilharziassnails and creation of a conducive environment for mosquito breeding.Table 5.8: Clinical data from Kasisi Rural Health Centre showing prevalent diseases inNgwerere areaKasisi Catchment Area (clinical data)Population 11,450Disease Year June 2000 2001 2002 2003 2004Malaria 3242 3459 2902 3575 4014Diarrhoea N/B 279 275 277 361 187Bilharzias 77 57 36 56 33Dysentery 30 41 65 122 66Other parts of the river catchment near stabilization ponds in garden Compound and nearovergrown parts of the river are likely to be affected by these diseases. The levels ofmicroorganisms as determined by laboratory analysis (see Section 5.4.2) clearly bring out theevidence of existing health risks associated with the river water. Moreover the river waterquality did not improve to the extent where it can be used for domestic use, especially drinkingafter receiving mainly municipal wastewater including wastewater from the residential and tradeareas, and the Lusaka Water and Sewerage Company treatment plants near the source andalong the river. Fifty four percent (54%) of the respondents in Ngwerere catchment said theriver water was not fit for drinking but was good for irrigation. However, fifty percent (50%) ofthem said none of the members of their household had suffered from any disease associatedwith the river water in the past one year. The answer to the question on disease infection couldhave been affected by bias because some of the respondents expressed fear that they wouldbe banned from using the water as some organizations had hinted in the past. Nevertheless,other factors could explain why the disease infection was lower than expected in the light of theperceived threat of using the river water for irrigation, namely:• Most respondent’s homes are far away (>3 km) from the river.• The fact that they are aware of the risk involved they take some precautions, e.g., some bring clean drinking water to the fields from safer sources.• Most of the frequently grown vegetables require cooking before eatingThe case at Kafue Lagoon was quite similar to the Ngwerere situation. Fifty three percent(53%) of the respondents said the water used for irrigation posed a threat to human healthwhile fifty percent (50%) said none of the members of their household had suffered any illnessas a result of the water they used for irrigation. However, at Kafue Lagoon area the distancebetween the wastewater streams and residential areas was shorter (about 1 km). In additionthe water from Lee Yeast and Shikoswe stream was visibly dark brown and laden with faecalmatter, respectively, so much that one would not obviously use it for domestic purposes. 35
  • 57. 5.1.15 Constraints faced by farmers in Kafue Lagoon and the Ngwerere areasThe constraints faced by farmers are indicated in the table below. The farmers indicated theproblem as minor, major or moderately.Tables 5.9: Constraints faced by farmers in growing their crops/vegetablesType of constraint Study sites Ngwerere River Area Kafue Lagoon AreasInadequate irrigation water xHigh input costs xxInadequate technical support xxx xxConveyance of water xxx xxxStorage of the crops is a big problem xxxThe crops became spoiled xxx xxPrice variation xxx xxxTransport expenses xxx xxxLack of credit for capital development xxxTheft of crops xxx xxxMarketing of produce xxx xxxNote:x – a minor problemxx – a moderate problemxxx – a major problem5.2 Quantity of wastewater in the Ngwerere River AreaThe total surface runoff and base-flow was computed by using the Hydata, spreadsheet andARIDA software at the Department of Water Affairs Water Resources Unit were used. Thesurface runoff was estimated by using Flow Duration Curves (FDC). A FDC is a cumulativefrequency curve that shows the percentage of time during which specified discharges wereequaled or exceeded during the period of a record. It represents a non-sequential series ofstream flow events and it combines in one curve the flow characteristics of a stream throughoutthe range of discharge without regard to the sequence of occurrence (UNESCO, 1984).Figure 5.6 shows the mean monthly flows for the Ngwerere River at Estate Weir station of theDepartment of Water Affairs. It shows the mean monthly flow for a period ranging from 1999 to2004. The figure shows the behaviours of the monthly and mean monthly flows at NgwerereEstate Weir in Chamba Valley area. 36
  • 58. Ngwerere River at Estate Weir - Mean monthly flows 10 Flow (cumecs) 1 0.1 0.01 1999 2000 2001 2002 2003 2004 Monthly flow Mean flow Figure 5.6: Ngwerere River mean monthly flowsTables 5.10 and Figure 5.7 shows the flow duration data for Ngwerere River at Estate weir. Theflow duration curve is used for analyzing hydrological data. According to Smakhtin (2000) andUNESCO (1984) a Flow Duration Curve (FDC) is a relationship between any given dischargevalue and the percentage of time that this discharge is equaled or exceeded. FDC is frequentlyused in water quality calculations, design of run-of-river abstraction schemes, and estimation ofrequired environmental flows. In this study the FDC was used to separate the surface runoffand base-flow from the total surface runoff. The results are shown in figure 5.8 and AppendixVIII. As can be seen in figures 5.7, 5.8, 5.9 and Annex VIII the Ngwerere catchment contributesenough base-flow from the groundwater storage.In hydrologic studies, flow duration values of 90, 95 and 99% (see Table 5.10 and Figure 5.7)are used as measures of a stream‘s low flow potential. The 90% value is used as a measure ofgroundwater contribution to stream flow (Cross, 1949). This same value has been used as ameasure of run-of –the-river hydro-power potential (Searcy, 1959). Other potential uses of thelow flow portion of a duration curve include analysis relating to irrigation and urban watersupplies.The low flow portion of the curve (Figure 5.6) is an index of the amount of groundwater beingcontributed to stream flow from natural catchment storage. If the slope of the curve in the lowflow portion is flat, groundwater contributions are significant. On the other hand a steep curveindicates poor base-flows and probable cease-to- flow conditions. Thus a duration curve is avaluable tool that can be used for comparing drainage basin characteristics, particularly theeffect of geology on low flows. The analysis shown in figures 5.6 and 5.7 are for onehydrometric station on the Ngwerere River at Ngwerere estate Weir. The hydrological dataanalyzed is from the 1970s to August 2004. There is significant contribution of groundwater tothe total surface runoff as can be seen in figure 5.6 and Appendix IX. 37
  • 59. 1 Day Flow Duration Jan to Dec 80.0 60.0 litres/second/sq km 40.0 20.0 0.0 0.01 0.10 1.00 10.00 50.00 90.00 99.00 99.90 99.99 Ngwerere River at Estate Weir Mean Daily Flowdwa 1-Oct-1970 to 30-Sep-2004 Figure 5.7: Flow Duration Curve for Ngwerere River Total Runoff and Baseflow in Millimeters 600 500 400 Millimeters 300 200 100 0 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 -100 Years Total runoff Base-flow Surface runoff Figure 5.8: Total, Base-flow and Surface Runoff 38
  • 60. Base Flow Index - Ngwerere River at Estate Weir 2.0 1.6666667 1.3333333 Flow (cumecs) 1.0 0.6666667 0.3333333 0.0 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 2002 2003 2004 Total Hydrograph Baseflow dwa 1-Oct-2001 to 30-Sep-2004 Figure 5.9: Total hydrograph and Base-flow from October 2002 to August 20035.3 Plant sample analysisHeavy metals were not detected in the water samples (water used for irrigation), some of themwere found in the plant and sediment samples. Mercury and copper were not detected in bothwater and plant samples.Table 5.10: Exploratory Analysis of Heavy Metals in Crops at Ngwerere River and KafueLagoon AreasTest Ngwerere Kafue Lagoon Areas Threshold River Area values (Anonymous) Leaves of Plot A (same crop of rape) Plot B rape Rape Medium Large leaves Sugar cane leaves of of rape rapeLead (Pb) mg/kg 0.07 0.07 0.012 0.02 5Copper (Cu) Not detected Not detected Not detected Not detected 50mg/kgZinc (Zn) mg/kg 0.095 0.082 0.123 0.005 50Cadmium (Cd) 0.049 0.049 0.028 0.036mg/kgMercury (Hg) Not detected Not detected Not detected Not detectedmg/kgIt was discovered from the laboratory analysis that mercury was not found in significantquantities (<0.0002 mg/l) in the sediments, it could mean that it was not present as a wasteproduct, hence not a threat to human health in these areas. Any detectable quantities of Hgcould also be from natural sources. Given the high pH values copper could have precipitatedout of solution into the sediments and so not much of it was available for the plant uptake after 39
  • 61. irrigation. A previous study by Sinkala et al (1996) reported less than 0.02 mg/l (detection limit)of Cu in the wastewater from NCZ and less than 0.011 and 0.018 mg/l (detection limits) of Cuin Lee Yeast effluents.Literature (Hide et al., 2001) indicated that cadmium could be present in the water column atvery low concentrations and yet build up in the plant tissue to levels that are harmful to humanhealth. Annex IV shows recommended maximum trace element concentrations in irrigationwater. For Cd the recommended maximum concentration is 0.01 mg/l in water. Others like Pb itis 5.0 mg/l, Zn 2.0 mg/l and Cu 0.20 mg/l. There were no reliable guideline values for heavymetals in plants against which comparisons could have been made. However, a study(workshop presentation) used 50 mg/kg as maximum concentration of Cu and Zn, and 5mg/kgPb in plant tissues.5.4 Water quality analysis5.4.1 Physico-chemical results5.4.1.1 Ngwerere RiverThe results obtained from the water quality analysis (see Appendix VII) indicated that most ofthe parameters including conductivity, salinity, calcium, sulphate, total nitrogen, totalphosphate, BOD, total suspended solids and iron tended to reduce in concentration from theupstream reaches in the urban area to the downstream reaches in the rural area of the rivercatchment. This indicated that the pollution was heavier in the former than in the latterstretches of the river. This could be explained by the fact that near its source, hence NgwerereRiver received effluents from industries (which need to be investigated further), markets andresidences near Lusaka town area, and from the Lusaka Water and Sewerage CompanyWastewater Treatment Plant (Manchinchi) in Garden Compound. Previous water qualitysurveys in 1996 and 1998 also found a similar trend (Tembo et al 1997; Silembo 1998).Though most of the physical and chemical parameters were within the recommended limits forirrigation and other uses, microbiological parameters showed that the river was heavilypolluted. Throughout the river stretch, the water was not suitable for drinking and at somepoints even for irrigation according to WHO and FAO guidelinesUnexpectedly, there were no heavy metals detected in the water. It is probable that metals likecopper and lead easily precipitated out of solution given the high pH values (8-10) found in theriver. For quality control/assurance purposes duplicate samples were obtained during selectedsampling campaigns and some samples taken to an independent laboratory for cross-checking.Nevertheless, the independent laboratory (Manchinchi Laboratory for Lusaka Water andSewerage Company) did not carry out the analysis in good time for reporting.Generally the physical-chemical parameters were within the limits of the ECZ, WHO, DWA andEU guidelines for water quality as shown in Table 5.11, 5.12 and 5.13. 40
  • 62. Table 5.11: Physical and chemical parameter of water sample analysis from Ngwerere Riverthree sampling sites ZNBS/DWA WHO drinking water drinking EU drinking guidelines water waterParameters N1 SD N2 SD N3 SD (permissible) guidelines guidelinespH 10** 0.7 8 0.5 8 0.7 6.5 - 9.0 6.5 - 8.5Conductivity 590 13 569 8 417 13 1500Water Temperature 18 0.4 16 0.4 18 1Salinity (%) 0.02 0.00 0.02 0.00 0.01 0.00 250Magnesium (mg/l) 36 10 36 9 43 15 150Calcium (mg/l) 81 6 84 11 53 12 200 500Sulphate (mg/l) 33 4 29 4 23 5 400 250Total Nitrogen (as N mg/l) 3 7 5 6 1 0Total Phosphates (as PO4-Pmg/l) 3 1 3 1 0.5 1 5.0Ammonia (as NH4-N mg/l) 4** 0.1 4** 0.1 0 0.1 0.5Biochemical OxygenDemand (O2 mg/l) 20 5 19 9 8 6Chemical Oxygen Demand(O2 mg/l) 72 24 39 23 38 21Total Suspended Solids(mg/l) 117 4 94 6 102 3 0Bicarbonates (as CaCO3mg/l) 330 14 333 33 263 18 500Nitrates (as NO3-N mg/l) 3 5 3 5 2 5 10 30Iron (mg/l) 1 1 0.3 0.6 1 1 1 0.3 0.1 - 3.0Sodium (mg/l) 232** 11 219** 9 219** 9 200? 200Lead (mg/l) 0 0 0 0 0 0 0.5 0.01 0.05Copper (mg/l) 0 0 0 0 0 0 1.5 2 -Cadmium (mg/l) 0 2 0 2 0 2 0.01 0.003 0.005Mercury (mg/l) 0 3 0 3 0 3 0.001 0.001 0.2Zinc (mg/l) 0 4 0 4 0 4 15 3 0.1 - 5.0Boron (mg/l) 1 5 1 5 1 5Note:**Values above WHO Standards 41
  • 63. Table 5.12: Physical and chemical parameter of water sample analysis from Ngwerere Riverthree sampling sites and their standard deviations Recommended max concentrationsParameters N1 SD N2 SD N3 SD (irrigation)pH 10 0.7 8 0.5 8 0.7 -Conductivity 590 13 569 8 417 13 --Water Temperature 18 0.4 16 0.4 18 1 -Salinity (%) 0.02 0.00 0.02 0.00 0.01 0.00 -Magnesium (mg/l) 36 10 36 9 43 15 -Calcium (mg/l) 81 6 84 11 53 12 -Sulphate (mg/l) 33 4 29 4 23 5 -Total Nitrogen (as N mg/l) 3 7 5 6 1 0 -Total Phosphates (as PO4-P mg/l) 3 1 3 1 0.5 1 -Ammonia (as NH4-N mg/l) 4 0.1 4 0.1 0 0.1 -Biochemical Oxygen Demand (O2mg/l) 20 5 19 9 8 6 -Chemical Oxygen Demand (O2mg/l) 72 24 39 23 38 21 -Total Suspended Solids (mg/l) 117 4 94 6 102 3 -Bicarbonates (as CaCO3 mg/l) 330 14 333 33 263 18 --Nitrates (as NO3-N mg/l) 3 5 3 5 2 5 -Iron (mg/l) 1 1 0.3 0.6 1 1 5Sodium (mg/l) 232 11 219 9 219 9Lead (mg/l) 0 0 0 0 0 0 5Copper (mg/l) 0.0 0 0 0 0 0 0.2Cadmium (mg/l) 0.0 2 0 2 0 2 0.01Mercury (mg/l) 0 3 0 3 0 3 -Zinc (mg/l) 0 4 0 4 0 4 2Boron (mg/l) 1 5 1 5 1 5 0.5 - 15 42
  • 64. Table 5.13: Physical and chemical parameter of water sample analysis from Ngwerere Riverthree sampling sites compared to ECZ effluent and wastewater standards ECZ Effluent and WastewaterParameters N1 SD N2 SD N3 SD StandardspH 10** 0.7 8 0.5 8 0.7 6.0 - 9.0Conductivity 590 13 569 8 417 13 4300Water Temperature (oC) 18 0.4 16 0.4 18 1 40Salinity (%) 0.02 0.00 0.02 0.00 0.01 0.00 -Magnesium (mg/l) 36 10 36 9 43 15 500Calcium (mg/l) 81 6 84 11 53 12 -Sulphate (mg/l) 33 4 29 4 23 5 1500Total Nitrogen (as N mg/l) 3 7 5 6 1 0 5.0Total Phosphates (as PO4-P mg/l) 3 1 3 1 0.5 1 6Ammonia (as NH4-N mg/l) 4 0.1 4 0.1 0 0.1 10Biochemical Oxygen Demand (O2 mg/l) 20 5 19 9 8 6 50Chemical Oxygen Demand (O2 mg/l) 72 24 39 23 38 21 90Total Suspended Solids (mg/l) 117** 4 94 6 102** 3 100Bicarbonates (as CaCO3 mg/l) 330 14 333 33 263 18 -Nitrates (as NO3-N mg/l) 3 5 3 5 2 5 50Iron (mg/l) 1 1 0.3 0.6 1 1 2.0Sodium (mg/l) 232 11 219 9 219 9 -Lead (mg/l) 0 0 0 0 0 0 0.5Copper (mg/l) 0 0 0 0 0 0 1.5Cadmium (mg/l) 0 2 0 2 0 2 0.5Mercury (mg/l) 0 3 0 3 0 3 0.002Zinc (mg/l) 0 4 0 4 0 4 10.0Boron (mg/l) 1 5 1 5 1 5 0.5Note:** Values above ECZ effluent and wastewater standardsGenerally the physicochemical parameters for Ngwerere River are within the limits of the ECZ,WHO, DWA and EU guidelines for water quality. However, the pH was higher than therecommended upper limit of 9 in a few cases especially at Kasisi orphanage. Ammonia levelsat N1 and N2 (that is urban and peri-urban areas) was higher than the WHO drinking waterguideline value of 0.5mg/l. On average sodium was higher than the guideline value of 200mg/lwhich can lead to the problem of specific ion toxicity. TSS at N1 and N3 were also higher thanthe ECZ guideline value of 100mg/l.All the other parameters measured were lower than the recommended maximum concentrationin irrigation water, according to Pescod (1997). The concentration of heavy metals and boron inthe water at all the sampling points were below the detection limit of the method of analysiswhich is also far below the recommended maximum concentrations. The parameters measuredat NCZ, were within the ECZ recommended limits. This was very different from the situation in1996 in the study of Sinkala et al, which reported higher levels of magnesium, calcium, totalsuspended solids and total dissolved solids. The difference may be attributed to slowed or noproduction at NCZ at the time of the present study. In fact the water in the effluent canal wasvisibly clear. At the time of sampling the farmers were mixing this water with that from LeeYeast factory and Shikoswe stream through diversion canals. 43
  • 65. From the results it is clear that the main problem with respect to the risk to human health is thepollution by microorganisms in the watercourses where the farmers draw water for irrigatingtheir crops. This was common for both studies –Ngwerere River and Kafue Lagoon Areas.For Ngwerere River only the last point (N3 about 23 km from source) qualifies for unrestrictedirrigation according to the WHO guideline value of ≤1000 faecal coliform/100ml, if only themean value for July 2004 is considered (900 faecal coliform/100ml). Under unrestrictedirrigation vegetables and salad crops can be grown using water with ≤1000 faecalcoliform/100ml. Therefore, the growing of vegetables at the other sites (N1 and N2) poses ahealth risk to workers (or producers) and the consumers. On the other hand the water in theNgwerere River is only fit for restricted irrigation whereby the crops that can be safely grownare cereal crops, industrial and folder crops, and pasture and trees (fruit trees). Plate 5.3 showsthe sampling point N3 at Kasisi Mission Dam.The reduction in pathogens at the lower reaches of the river (Kasisi Mission) evidenced by thereducing counts of E.coli and Faecal streptococci. At all the stations on the river the water wasnot suitable for drinking. Previous studies also demonstrated similar patterns especially that thesampling points used in this study were also used in the past.In Kafue Lagoon Areas, the Shikoswe and Lee Yeast effluent streams also had their meanvalues above the WHO guideline of <1000 faecal coliforms/100ml. 44
  • 66. Plate 5.3: Below Spill way at Kasisi Dam (third sampling point along the Ngwerere River) 45
  • 67. 5.4.1.2 Kafue Lagoon AreaFor NCZ according to Table 5.14 and 5.15, the parameters measured were within the ECZrecommended limits. This was very different from the situation in 1996 under the study ofSinkala et al, which reported higher levels of magnesium, calcium, total suspended solids andtotal dissolved solids. The difference may be attributed to slowed or no production at NCZ atthe time of the present study. In fact the water in the effluent canal was visibly clear. At the timeof sampling it was found that the farmers were mixing this water with that from Lee Yeastfactory and Shikoswe stream through diversion canals. Plates 5.4, 5.5 and 5.6 show theappearance of effluents from Lee Yeast and sampling points on NCZ and Shikoswe effluentcanals respectively.Table 5.14: Physical and chemical parameter of water sample analysis from NitrogenChemicals of Zambia compared with ECZ effluent and wastewater standardsParameter 11.08.04 18.08.04 ECZ Limit (point source)pH 7.7 6.8 6.0 - 9.0Conductivity (uS/cm) 223 258 4300Water temp 21.6 22.1 40Salinity (%) 0.00 0.00 -Magnesium (mg/l) 16.08 - 500Calcium (mg/l) 31.6 - -Sulphate (mg/l) 36.6 - 1500Total Phosphates (as PO4-P mg/l) 0.48 - 6.0Ammonia (as NH4-N mg/l) 0.20 - 10Total Suspended Solids (mg/l) 4 - 100Iron (mg/l) 0.44 0.01 2.0Sodium (mg/l) 109.2 124.05 200*Lead (mg/l) <0.01 <0.01 0.5Copper (mg/l) <0.003 <0.003 1.5Cadmium (mg/l) <0.002 <0.002 0.5Mercury (mg/l) <0.0002 <0.0002 0.002Zinc (mg/l) 0.0695 0.0555 10 46
  • 68. Table 5.15: Physical and chemical parameter of water sample analysis from Shikoswe streamin Kafue Lagoon area compared with ECZ effluent and wastewater standardsSampling Date 08.07.2004 20.07.2004 11.08.2004 18.08.2004 ECZ Limit (point source)pH 7.9 8.2 7.8 6.3 6.0 - 9.0Conductivity 343 390 348 324 4300Temperature 19.4 20.1 24.8 25.2 40Salinity 0.01 0.01 0.01 0.01 -Sulphate (mg/l) 29.2 27.2 - 1500Ammonia (as NH4-N mg/l) 3.32 4.598 3.1 4.88 10Total Suspended Solids (mg/l) - 45 56 100Bicarbonates (as CaCO3 mg/l) 198 230 203 - -Nitrates (as NO3-N mg/l) - 0.69 - 50Magnesium (mg/l) - - - 29.5 -Calcium (mg/l) - - - 29.6 -Total Phosphates (as PO4-P mg/l) 15.6 6Iron (mg/l) 0.54 0.60 <0.01 2.0Lead (mg/l) <0.01 <0.01 -- - 0.5Copper (mg/l) <0.01 - - - 1.5Cadmium (mg/l) <0.002 - - - 0.5Mercury (mg/l) <0.0002 - - - 0.002Zinc (mg/l) <0.001 - - - 1.5Boron (mg/l) <0.5 - - - 0.5For Lee Yeast the conductivity was higher than the recommended standard of 4300uS/cm(ECZ) as shown in Table 5.16. The phosphate and calcium levels were abnormally higher thatthe recommended limits by ECZ although this was just for one sample. High calcium andconductivity (as TDS) levels were also reported by Sinkala et al (1996) (Annex XIV). Thesource of the calcium is mainly the geology of the area. The high conductivity corresponds tohigh sodium content of the effluent. 47
  • 69. Table 5.16: Physical and chemical parameter of water sample analysis from Lee Yeastcompared with ECZ effluent and wastewater standards ECZ Limit (point 08.07.04 20.07.04 11.08.04 18.08.04 source)pH 8.0 8.9 8.9 7.9 6.0 - 9.0Conductivity 5600** 6420** 6400** 6350** 4300Temperature 16.3 18.3 25.5 27.3 40Salinity 0.30 0.34 0.34 0.33 -Ammonia (as NH4-N mg/l) 2.85 2.18 0.965 2.685 10Total Suspended Solids (mg/l) - - 242 220 100Magnesium (mg/l) - - - 224.4 -Calcium (mg/l) - - - 7812.85 -Total Phosphates (as PO4-P mg/l) - - - 62.65** 6Bicarbonates (as CaCO3 mg/l) 328 334 329 - -Nitrates (as NO3mg/l) - 1185 - 50Iron (mg/l) 1.43 1.1 1.36 - 2.0Lead (mg/l) <0.01 0.08 - - 0.5Copper (mg/l) <0.01 - - - 1.5Cadmium (mg/l) <0.002 - - - 0.5Mercury (mg/l) <0.0002 - - - 0.002Zinc (mg/l) <0.001 - - - 1.5Boron (mg/l) <0.5 - - - 0.5Note:** Values higher that the ECZ standardsThe concentration of heavy metals and boron in the water at all the sampling points were belowthe detection limit of the method of analysis which is also far below the recommendedmaximum concentrations.The Shikoswe effluent had relatively high levels of ammonia and phosphate, the reason beingthat it carries mainly sewage effluents. As in Lee Yeast effluents, Shikoswe had also high levelsof iron. The iron was also high in the sediments. However with respect to human health,through crop production, it does not pose a threat.The high salt content (as conductivity) of the irrigation water used at both study sites,threatened the well being of the soil in the fields under irrigation. The sodium adsorption ratio(SAR) for N1, N2 and N3 (Table 5.17) and at Kafue Lagoon Area (NCZ) were 31, 28, 32 and22, respectively. The values were higher than the Ayers and Westcot (1985) guideline value of9 (see Annex III) beyond which the fields under irrigation would experience severe specific iontoxicity affecting sensitive crops and also increasing soil salinity problems. High salinity led toreduced uptake of water and nutrients by plants. The concentration of heavy metals and boronin the water at all the sampling points were below the detection limit of the method of analysiswhich was also far below the recommended maximum concentrations. 48
  • 70. Plate 5.4: Crop in Kafue Lagoon Area near effluent channel from Lee YeastPlate 5.5: NCZ effluent channel near the footbridge on the Left side of the picture (Samplingpoint)Plate 5.6: Shikoswe stream carrying sewerage effluent near NCZ going into the lagoon (NCZright side of the picture) 49
  • 71. Table 5.17: Sodium Adsorption Ratio for Ngwerere RiverSodium Absorption Ration (SAR)Ngwerere River Area Averages SDSAR (N1) 30.2 27.5 32.3 29.6 33.1 31 2SAR (N2) 28.7 28.7 27.8 26.7 29.8 28 1SAR (N3) 29.2 31.7 33.0 34.8 30.1 32 25.4.2 Microbiological ResultsThe microbiological results, their mean values and standard deviations of the entire samplingperiod (7th July – 19th August 2004) are presented in Tables 5.18 and 5.19 below. ForNgwerere River, N1 to N3 represented sampling stations on the river from the upstreamreaches (about 3km from the source) to the down stream reaches (about 23 km from thesource). Refer to Figure 3.1 for the map of the Ngwerere area and also Figure 3.2 for the mapof the Kafue Lagoon area with sampling points highlighted. The sampling points were picked onthe effluent streams: Nitrogen Chemicals of Zambia carrying effluent from the factory,Shikoswe stream carrying effluents mainly domestic wastewater and the Lee Yeast carryingeffluent from the factory but somewhat mixed with sewage. The effluents from Lee Yeast andShikoswe were heavily contaminated with respect to faecal coliforms. The water was not safefor use without treating it.Table 5.18: Bacteriological analysis in the Ngwerere at three sampling sites showing organismsper 100mlNgwerere River Sampling dateSampling Date 7.7.04 8.7.04 12.7.04 13.7.04 16.7.04 04.8.04 05.8.04 19.8.04 Mean SDFaecal coliformN1 12,000 9,000 9,300 4,000 3,100 18000 17500 9000 10,000 5000N2 4,000 5,000 1,700 8,500 2,000 12350 15000 8700 7,000 5000N3 340 380 1,200 1,400 1,200 7850 9000 1000 3000 4000E.coliN1 120 96 6,200 2,200 2,200 500 520 7000 2,000 3000N2 100 100 1,000 4,000 1,200 453 470 6100 2000 2000N3 90 90 400 500 1,000 313 175 700 400 300Faecal StreptococciN1 900 70 500 1,000 220 8000 8500 290 2,000 4000N2 400 388 100 1,500 210 5500 7500 320 2000 3000N3 70 10 400 300 190 1385 1805 420 600 700 Note: SD=standard deviation 50
  • 72. Table 5.19: Bacteriological analysis in the Kafue Lagoon area at three sampling sites showingorganisms per 100mlKafue Lagoon Sampling dateSampling Date 08.07.04 20.07.04 11.08.04 18.08.04 Mean SDFaecal coliformLee Yeast 8,000 4,000 2000 5000 3000Shikoswe Stream 8,000 3,300 8900 2500 6000 3000E.coliLee Yeast 5,000 2,000 1800 3000 2000Shikoswe Stream 76 1,200 3750 2000 2000 2000Faecal StreptococciLee Yeast 120 800 180 400 400Shikoswe Stream 96 1,000 2150 210 900 900Note:SD=standard deviationWestcot (1997) argued that the WHO or Engelberg standards for faecal coliforms were designguidelines and suggested that in the absence of better information, it is “prudent” to use themas the quality standard to aim for in waters that are known to currently fall short of that quality.Therefore, in this study, the water quality was interpreted with respect to the WHO guidelinesand recommendations by Westcot considering the fact that adequate epidemiological andwater quality information was not available at the time of the current study. The following table(Table 5.18) shows the ranges of contamination and recommendations by Westcot (1997)based on a minimum of 5 (five) samples taken over the irrigation season.Table 5.20: Ranges of Contamination and Recommendations (after Westcot, 1997)Mean number of faecal coliforms/100ml Recommendation<1000 (<103) Appropriate for the irrigation of vegetables1000, - 10,000 (103 – 104) Potentially safe if the source of contamination (presumed to be localized) can be eliminated10,000 – 100,000 (104 – 105) Heavy contamination requiring treatment before the water can be used for unrestricted cropping>100,000 (>105) Extensive heavy contamination-highly unsuited for irrigationCompared to Table 5.14 above, the water at both Ngwerere and Kafue Lagoon area waspotentially safe as long as the pollution sources were eliminated. But elimination of the sourcesof pollution is not feasible in both situations because the contaminated water is also the waterused for irrigation by the peasant farmers in these areas and is their main source of incomeand food. Other options such as improving the efficiency of wastewater treatment plants(especially desludging) upstream or expanding the treatment plants may be considered. Thereare large variations in the faecal coliform numbers at each point on the Ngwerere River overthe study period, hence high standard deviations. This was probably due to variation inwastewater discharges and composition, flow pattern of the river and its tributaries andabstraction for irrigation. Such variations in coliform counts were also reported in a study inGhana carried out by Cornish et al (1990). Between points N2 and N3, there were massiveabstractions of water from the river and a few dams by large-scale farmers. However it was notverified whether there was significant return flow from the farms. 51
  • 73. In terms of the spatial distribution of the microorganisms on the Ngwerere River, the log plot(Figure 5.9) shows that more organisms (hence more pollution) were found upstream in theurban/peri-urban area of Lusaka City (N1 and N2) than downstream in the rural area. Mean spatial distribution of microorganisms 10,000 log (number per 100ml) 1,000 Faecal coliform E.coli 100 Faecal Streptococci 10 1 N1 N2 N3 Sampling site Figure 5.10: Logarithmic plot of microorganisms at 3 sites along Ngwerere River Mean number of microorganisms at Kafue Lagoon Faecal coliform 10,000 log (number per 100ml) E.coli 1,000 Faecal 100 Streptococci 10 1 Lee Yeast Shikoswe Stream sampling sites Figure 5.11: Logarithmic plot of number of microorganisms at 2 sites at Kafue Lagoon5.5 Sediment analysis from the Ngwerere River and Kafue lagoon AreaThe sediment samples were analyzed at both sites for exploratory purposes. Detailedinvestigations should be carried out in future.The spot samples analyzed brought out interesting findings, which would help to explain orconfirm variations in the other sample types in limited mass balance terms. Two samples werecollected on different days at both sites. After about a week, there was a high increase in theconcentration of Zn, Fe, Pb and Cu at the first two sites (N1 and N2) on the Ngwerere River.For instance for Cu it was over 6 times and for Zn it was over 9 times. But at the last site (N3),there was a marked concentration decrease in all the metals. However there seems to be noconsistent trend in the data sets that can explain fully the variations, especially, given thevariation in effluent discharges to the river and the seemingly high rates of deposition orremoval of sediments. What is generally expected is that when the flow velocity of the riverreduces the amount sediment deposition increases and vice-versa. 52
  • 74. Table 5.21: Analyzed sediment quality from Ngwerere three sampling sites compared to DutchSediment Quality GuidelinesSample Id N1 N1 N2 N2 N3 N3 Dutch Sediment Quality GuidelineParameter (Class I)Sampling Date 07.07.04 13.07.04 07.07.04 13.07.04 07.07.04 13.07.04Lead (mg/kg) 0.13 1.38 0.5 1.57 1.17 0.62 <530Copper (mg/kg) 0.16 7.51 0.33 1.85 1.85 1.27 <35Cadmium (mg/kg) <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <2Mercury (mg/kg) <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.5Zinc (mg/kg) 0.969 8.8 1.266 1.838 1.636 0.185 <480Iron (mg/kg) 75 1,596.30 282 480.93 1,310 312.63 -Table 5.22: Analyzed Shikoswe stream and Lee Yeast sediments from the Kafue Lagoon areacompared to Dutch Sediment Quality GuidelinesLab No. 40451 40455 40456 Dutch Sediment Quality Guideline (Class I)Sample Id Shikoswe stream Shikoswe stream Lee YeastParameterSampling Date 08.07.2004 20.07.2004 20.07.2004Lead (mg/kg) - 0.82 0.85 <530Copper (mg/kg) 0.04 58 1.51 <35Cadmium (mg/kg) <0.002 <0.002 <0.002 <2Mercury (mg/kg) <0.0002 <0.0002 <0.0002 <0.5Zinc (mg/kg) <0.001 15.6 11.2 <480Iron (mg/kg) 8.62 1,503 1,175 - At Kafue lagoon, there was also an increase in the heavy metal content after 12 days at theShikoswe stream site, also indicating a relatively high rate of deposition. Cd and Hgconcentrations were below the detection limit at all the sampling points in the two study sites,indicating that very little quantities of both metals are introduced in the watercourses and somay not be a serious threat to the environment. Moreover, on the Ngwerere River there are noknown industrial discharges.Since there are no local guidelines for heavy metals in sediments, the results in this study werecompared with the standards in the Netherlands although this country is more industrializedthan Zambia. From the comparison with Class I (best class) out of four classes, all thesamples are way below the maximum heavy metal class concentrations except for Cu (58mg/kg) at Shikoswe stream, which was very high. But this was a one off value, which wouldrequire further verification. 53
  • 75. CHAPTER 6: CONCLUSION AND RECOMMENDATIONS6.1 IntroductionThe study on the use of wastewater for irrigation on vegetable growing in the Ngwerere Riverand Kafue Lagoon areas was essentially carried out within four months, of which only two wereeffectively used for data collection and preparation of progress report. Given the short period ofdata collection, the impacts of using wastewater on crops/vegetables yield were notquantitatively measured. In order to measure the impact it was realized that a longer studyperiod would be required which could cover the growing season of some selected crops. Sucha study would incorporate a control measure, that is, a selected plot of land under irrigation withnatural water free from the influence of the wastewater used for irrigation in each of the twostudy areas.In addition, the associated impact on the social economic status of the peasant farmers wasnot fully captured either. This was further affected by the missing information on other sourcesof food and cash income and expenditure patterns. In part, the reason for the missing data wasthe main limitation of time and also the distances to be covered. Another reason is that therespondents were better accessed at their fields than at home due to the design of the study.Otherwise more information could have been supplied with input from other household orcommunity members or by physical observation at their homes. It is also worth noting that thiscould demand a detailed household survey and an improved questionnaire, which in thecontext of this study was not possible as there were other parameters (for instance wastewaterquality) to be measured at the same time. Therefore the stated figures of income from the saleof crops by the peasant farmers were only indicative values.Going by the above explanation, some of the socio-economic and environmental impactindicators would only be justifiably measured over a longer period. However, the studysuccessfully demonstrated that the water in Ngwerere River and Kafue Lagoon was suitable forrestricted irrigation and that it was not suitable for drinking. Furthermore, wastewater reuse inurban/peri-urban agriculture was found to be a practical solution for alleviating poverty in rural,urban and peri-urban areas. Therefore, it is worthwhile to continue using the water for irrigationin both study areas, taking into consideration acceptable wastewater reuse guidelines,appropriate treatment, environmental and public health monitoring and education/publicawareness among affected communities.6.2 Achievement of specific objectives of the study The impact of the wastewater on crop yield was not adequately assessed and the link to the socio-economic well being of the peasant farmers was not firmly established. However, from the responses obtained, it was clear that growing and selling of high value crops/vegetables using wastewater or nutrient enriched water was the main or only source of livelihood for many of the respondents in both study areas. At Kafue Lagoon all respondents depended only on this type of urban agriculture. Furthermore, the authors of this report agree with Khouri et al (1994) who indicated that the need for a wastewater reuse project would be revealed if a physical, natural resources-oriented survey complemented by a socio-economic study of the target community was conducted. The study found out that malaria and diarrhoeal diseases were the most prevalent in both study areas but this was only verified at one health centre (Kasisi Rural Health Centre). However, it was not possible to determine whether the diseases (which included bilharzias, 54
  • 76. dysentery and cholera) were caused by the wastewater because the secondary data was limited and there was a tendency by some respondents to hide such information. The hiding of information was probably because they feared that they would be stopped from using the wastewater. The list of relevant parameters for wastewater quality evaluation was relatively comprehensive, the samples were reliably analysed and the potential sources of health hazards were determined. For instance biological contamination of the water, and probably the crops produced, was the major threat to the health of the farmers and consumers in Ngwerere and Kafue Lagoon and at the target markets in Lusaka and Kafue. The studies by Tembo et al (1997) and Sinkala et al (1996) also found high coliform counts in the Ngwerere River and Kafue Lagoon, respectively. Heavy metals (Hg, Pb, Zn, Cu, Cd) were not found in the water samples at both study areas but there were significant quantities of Cu, Pb, Zn and Fe in the sediments. Low heavy metal content in water samples from Kafue Lagoon was also found by Sinkala et al (1996). The analysis of heavy metals in plants revealed that cadmium could pose a threat to human health as it was detected in appreciable quantities in plants at both study areas in one sampling campaign. Moreover, Hide et al (2001) indicated that cadmium could be present in the water column at very low concentrations and yet build up in the plant tissue to levels that are harmful to human health. The plant sampling was done for exploratory purposes but a detailed investigation of cadmium in the vegetables and sugarcane could verify the findings. Measures of reducing health hazards associated with the use of wastewater in crop/vegetable growing were proposed and these include improving the efficiency of wastewater treatment plants, sensitization and education of affected communities and consistent monitoring of the wastewater quality. It was found that the peasant farmers did not observe safe handling of the wastewater during irrigation. For instance they used buckets for watering. Buckets accentuate the risk of contamination of the plants and farmers according to Egziabher et al., (1994). So there was need for appropriate educational and public awareness programs as recommended by Hussain et al (2002). Results also indicated that wastewater, which was discharged at both study sites, was inadequately treated or not treated at all and this situation was common in many developing countries as observed by Hussain et al (2002). For instance in Ngwerere the design capacity of Manchinchi WWTP (36,000 m3/day) was sometimes exceeded up to 80,000 m3/day. Although the environmental valuation of wastewater by the community was fully assessed, also due to time limitation, the peasant farmers valued wastewater as a major source of irrigation water to sustain their farming activities, hence a resource that could help them earn a living. This was in agreement with the findings in the report by the International Water Management Institute in 2003 (IWMI, 2003) that wastewater agriculture has accounted for over 50% of urban vegetable supply in several Asian and African cities. The findings of other researchers such as Khouri et al (1994), Hussain et al (2002), (Hide et al., 2001), Cornish et al. (1990), Egziabher et al. (1994) and Idelovitch and Ringskog (1997) support the need for reuse of wastewater while emphasizing adherence to acceptable wastewater reuse standards.Overall, the first and last specific objectives were partially attained, while the second and thirdwere fully attained as explained above. 55
  • 77. 6.3 ConclusionsBased on the findings from the study, the following are the conclusions:1. Although the impacts of using wastewater on crops/vegetables yield were not quantitatively measured, it was established that the growing and selling of crops in both study areas was the main source of cash income and food for most of the peasant farmers. The high unemployment levels and the general poor state of the economy in Zambia left them with few or no alternatives for earning a living. For example all the respondents (30) in Kafue Lagoon mainly depended on farming. The average income earned from sale of crops ranged from K400, 000 to K1, 000, 000 in Kafue Lagoon and K400, 000 to K2, 500, 000 in the Ngwerere River Area. However, the figures could have been understated because the respondents did not have records of their sales, which varied greatly according to the crop type and season, and also because they wanted to show that they were less privileged in the hope of receiving some assistance.2. The relevant parameters were measured in water, plants and sediments from the Ngwerere River and Kafue Lagoon Area and compared with ECZ, WHO, EU, ZABS standards and others to determine the suitability of the water for various uses especially irrigation. It was found that the water in the Ngwerere River and Kafue Lagoon Area was suitable for restricted irrigation of folder crops, and fruit trees. In the rural area of Ngwerere (i.e., Kasisi Mission area) the water could be used for unrestricted irrigation of salad crops and vegetables. Therefore, vegetable growing in the urban/peri-urban part of the Ngwerere River and in the Kafue Lagoon Area put the health of both the producer and consumer at risk. The water at all sampling points was not suitable for drinking due to high levels of faecal coliforms.3. Heavy metals in the water at all the sampling points were below the detection limit. The heavy metals in plant tissue and to some extent in the sediments were below the maximum recommended limits although bioaccumulation capacities of cadmium and lead need to be considered further.4. Health risks associated with the use of wastewater in the Ngwerere and Kafue Lagoon Area could be reduced if the contaminants (especially pathogens) were reduced or eliminated at the source through improved treatment.5. The sludge in the Manchinchi maturation ponds could have reduced the retention time of the wastewater for the pathogen to die off before discharging into the environment. Maturation ponds are primarily used to reduce faecal bacteria and viruses to safe levels so that the effluents can be used without risk to human health and the environment.6. The main irrigation method practiced during the study was the use of containers that accentuated the risk of contamination of the plants and farmers7. In both study areas the users considered the wastewater to be economically valuable for irrigating crops in spite of risks associated with using such water, more so because crop production using the same water was the main source of income and food. All of the respondents were willing to contribute towards improving the water quantity and quality.8. Measurement of impacts of using wastewater on crop yield and socio-economic implications would require a longer study period (not less than one year) than that allowed for the present study, and the same applies to seasonal variations in the quality and quantity of water used for irrigation. For instance the impact of high sodium adsorption ratio (SAR), averaged 30 for Ngwerere River water, could be understood better after collecting more data throughout the year.9. Wastewater was the only source of water used irrigation along the Ngwerere river and in the Kafue Lagoon area 56
  • 78. 6.4 RecommendationsFrom the study the following were the recommendations:1. Policy makers should focus on reuse of wastewater as a resource for irrigation in peri- urban/or urban and rural areas in order to enhance food security and poverty alleviation at both household and national level2. From the results, and according WHO wastewater reuse guidelines, it is recommended that restricted irrigation of folder crops, and fruit trees should be practiced from the source up to Ngwerere Estate Weir on Ngwerere River and in the Kafue Lagoon Area. Unrestricted irrigation of salad crops and vegetables should only be practised around Kasisi Mission area on Ngwerere River and downstream to the confluence with the Chongwe River.3. The Ministry of Health (MoH) and NGOs (e.g., Water and Sanitation Association of Zambia, CARE International and Lifegate Foundation) should sensitize and raise public awareness on health risks associated with using and handling of untreated wastewater or pretreated wastewater4. The Lusaka Water and Sewerage Company with support from the Ministry of Local Government and Housing (MLGH) should rehabilitate their wastewater treatment plants that discharge effluents into the Ngwerere River so as to treat effluents to acceptable environmental standards. Similarly MLGH (particularly Kafue District Council), ECZ, Lee Yeast Factory and Nitrogen Chemicals of Zambia should work at improving the quality of wastewater before discharging into the environment. This would help the urban/peri-urban farmers to use wastewater of acceptable quality for irrigation.5. The government, civil society and the private sector should assist peasant farmers in forming peri-urban and urban farmers associations or co-operatives, which can deliberate, and act on issues such as marketing, input supply as well as credit6. The Ministry of Agricultural and Cooperatives, Department of Water Affairs and other responsible institutions should sensitize the peasant farmers and politicians on land use pattern and the dangers associated with river bank cultivation7. In all sensitization programmes on wastewater use, alternative livelihood sources should be considered8. The Ministry of Health with help from NGOs and co-operating partners should undertake mass de-worming programmes in communities living near Kafue Lagoon area and Ngwerere sub-catchment so that there is a balance to protect the health of farmers and consumers and at the same time helping to safeguard the livelihoods of the peasant farmers9. The government (through e.g., University of Zambia, National Institute for Scientific and Industrial research, National Science and Technology Council and MLGH) should focus on how the water quality could be improved through pre-treating wastewater prior to use, perhaps with small-scale wetland systems or shallow wells or other appropriate technology10. Further research needs to be undertaken to cover gaps identified in this study11. Department of Water Affairs should continue from where this study ended in routine water quality monitoring of the Ngwerere River against the effluents received by the river. The information from river quality monitoring can then be used by the Environmental Council of Zambia to mitigate the impact of the pollution on the environment. 57
  • 79. REFERENCESBlumentthal U. J., Mara D. D., Peasey A. and Ruiz-Palacios G. and Stott. Guidelines for themicrobiological quality of treated wastewater used in agriculture: recommendations for revisingWHO guidelines, Environment and Health, Bulletin of the World Health organization 2000,78(9) 1105Braden, John B. (2000), Value of valuation: Introduction. Journal of Water Resources Planningand Management, Vol. 126, no. 6, pp. 336-338.Central Statistical Office (2003), 2000 census of population and housing. Republic of ZambiaLusakaCifuentes E. M. Gomez, U. Blumenthal, M. M. Tellez-Rojo, I. Romieu, G. Ruiz-Palacios, andS.Ruiz-Velazco (2000), Risk factors for Giardia intestinalis infection in agricultural villagespracticing wastewater irrigation in Mexico. American Journal of Tropical Medicine and Hygiene.62(3): 388-392.Cooper, R.C. (1991), Public health concerns in wastewater reuse. Water Science andTechnology. 24(9):55-65.Cornish G. A., Mensah E and Ghesquire P (1990), Water quality and peri-urban irrigation: Anassessment of surface water quality for irrigation and its implications for human health in peri-urban zones of Kumasi, Ghana: KAR Project R7132, Report OD/TN95, HR WallingfordMara D. D, (1998), Guidance Manual on water Supply and Sanitation Programme, DFID,WEDCDubbeling M. and Santanddreu A. (2003), Urban Agriculture: A tool for Sustainable MunicipalDevelopment. Guidelines for Municipal Policymaking on Urban Agriculture, No 1 First EditionIWMI-RUAF E-CONFERENCE: Agricultural use of untreated urban wastewater in low incomecountries 24 June - 5 July 2002Egziabher A. G., Maxwell D. G., Lee-Smith D, Memon P A, Mougeot L J A, Sawio C J. (1994),Cities Feeding People. An examination of urban agriculture in East Africa. IDRC, Ottawa,Canada.Ensink, J. H. J., W. van der Hoek, Y. Matsuno; S. Munir and M. R. Aslam (2002), Use ofuntreated wastewater in peri-urban agriculture in Pakistan: Risks and opportunities. ResearchReport 64. Colombo, Sri Lanka: International Water Management Institute.Environmental Council of Zambia, Enviro – line, Issue No. 1, May – August 1998.Environmental Council of Zambia and Lusaka City Council (1997), Solid Waste ManagementPlan Project, Phase 1- Diagnosis Final ReportEnvironmental Council of Zambia (1994), State of the Environment Report, Lusaka 58
  • 80. Feenstra S., R. Hussain and W. van der Hoek (2000), Health Risks of Irrigation with UntreatedUrban Wastewater in the Southern Punjab, Pakistan, IWMI Pakistan Report no. 107.International Water Management Institute, and Institute of Public Health, Lahore.Ghoshi B. N. (1992), Scientific Methods and Social Research, Sterling Publishers PrivateLimited, New Delhi, IndiaGKW Consult (2001), Water Supply and Sanitation study in Central Province, Zambia. SectorReview and Design Criteria Report, LusakaHide J. M., Kimani J., and Kimani J. T. (2001), Informal irrigation in the Peri-urban Zone ofNairobi, Kenya: An Analysis of Farmers Activities and Productivity. Report OD/TN 104Hide J. M., Hide C. F. and Kimani J. (2001), Informal irrigation in the Peri-urban Zone ofNairobi, Kenya: An assessment of surface water quality used for irrigation. Report OD/TN 105Huang J. Y. C (1994), ‘Sewage Disposal’ Microsoft ® Encarta, Funk and Wagnall’s CorporationHabbari, K.; A. Tifnouti; B. Bitton; and A. Mandil (2000), Geohelminthic infections associatedwith raw wastewater reuse for agricultural purposes in Beni-Mellal, Morocco. ParasitologyInternational, 48, 249-254.Hussain I., L. Raschid, M. A. Hanjra, F. Marikar and W. van der Hoek (2002), Wastewater usein agriculture: Review of impacts and methodological issues in valuing impacts. Working Paper37. Colombo, Sri Lanka: International Water Management Institute.Idelovitch E. and Ringskog K. (1997), Wastewater treatment in Latin America, Old and NewOptions, World Bank, Washington DCInternational Water Management Institute (IWMI), Confronting the Reality of Wastewater Use inAgriculture; Water Policy Briefing Series No. 9, August 2003,Karpagma M (1999), Environmental Economics, Sterling Publishers Pvt. LTD, New Delhi.Kelderman P. (2001), Environmental Chemistry, with special emphasis to aquatic sediments.International Institute for Infrastructure, hydraulic and Environmental engineering. TheNetherlandsKhouri N., Kalbermatten J. M. and Bartone C. R. (1994), Reuse of Wastewater in Agriculture: Aguide to Planners, UNDP-World Bank Water and Sanitation Programme: The World Bank,Washington, DCMara D. D: ‘Low-cost wastewater treatment and reuse’ Water, DFID, issue 5, November, 1997pp7Mara, D. D. (1997), Wastewater treatment in hot climates. In Water, wastes and health in hotclimates, ed. R. Feachem, M. McGarry and D. Mara. Chichester, United Kingdom: John Wileyand Sons.Mara, D. D. (2000), The production of microbiologically safe effluents for wastewater reuse inthe Middle East and North Africa. Water, Air, and Soil Pollution. 123(1-4): 595-603. 59
  • 81. Ministry of Finance and National Planning (2002), Poverty Reduction strategy Paper, LusakaMinistry of Energy and Water Development (1994), Zambia National Water Policy, Lusaka.National Scientific Research (1983), Pollution Surveillance in Zambia – Ngwerere-ChongweRiver System, LusakaNaser Faruqui, Mark Redwood and Malick Gaye (2002), Reuse of Untreated Wastewater inMarket Gardens in Dakar, Senegal, UA-Magazine December 2002 pp 35-36Nicholas ODwyer and Partners Consulting Engineers (1978), Extension of Present SewageTreatment Plant, Main Sewage and Associated Pumping Station at Kafue, Kafue TownshipCouncilPescod M (1992), Wastewater treatment and use in agriculture. FAO, irrigation and DrainagePaper no. 47. Rome: FAO. ISBN 92-5-103135-5. 125ppPrice J. (2003), Treatment and Use of Wastewater in Urban Agriculture: Guidelines forMunicipal Policy makers on Urban Agriculture. Paper No. 6 First Edition March 2003Rose G. D. (1999), Community-Based Technology for Domestic Wastewater Treatment andreuse: options for urban agriculture. CITIES FEEDING PEOPLE CFP REPORT SERIES Report27Scott C. A., Zarazua J. A. and Levine G. (2000), Urban-Wastewater Reuse for Crop Productionin the Water-Short Guanajuato River Basin, Mexico. Colombo, Sri Lanka, International WaterManagement Institute.Shuval H. I. (1991), Health Guidelines and Standards for Wastewater reuse in Agriculture:historical perspectives. Water Science and Technology 23:2,073-2,080Sinkala T., Kanyomeka L., Simukanga S., Mwasa M., Sikazwe O. N., Nsomi C. M., Mwase-Ngulube E. T., Lewanika M., Kasuta E., Mwale M. S. and Musonda M. M. (1996), Control ofAquatic Weed in the Kafue River Basin between Iteshi-teshi Dam and Kafue Gorge (March1996 – March 1997), (draft) Final ReportSmakhtim V. U (2000), Estimating Daily Flow Duration Curves form Monthly Stream Data,Water SA, Vol. 14, 13-18Steenvoorden J., Van Lier J., and Huibers F. (2004), Wastewater Re-use and GroundwaterQuality, IAHS Publication No. 285Tembo J. M., Bolsius M., Handia L. and De Koning J. (1997), Preliminary research on the NgwerereRiver Water Quality, Delft University of Technology, Department of Water Management and Departmentof Civil Engineering – University of Zambia, LusakaUSEPA (United States Environmental Protection Agency) (1992), Guidelines for water reuse.Washington, U.S.A.: USEPA. 60
  • 82. UNESCO (1982), Methods of Computing Low Stream Flow, Imprimerie de la Manutention,Mayeme, ParisWestcot D (1997), Quality control of wastewater for irrigated crop production. FAO. WaterReport No. 10. Rome: FAO 86p ISBN 92-5-103994-1World Health Organization (1989), Reuse of Effluents: Methods of wastewater in agricultureand aquaculture. Geneva: Tech. Report Series 778WWI, Wastewater Treatment in Egypt, Vol 4, No 4 (August 1989)Zambia Bureau of Standards (1990),Zambian Standard Specification for Drinking Water Quality(ZS 190:1990 ICS 13.060.20)Zambezi River Authority (2003), Zambezi River Authority Water Quality Guidelines forLivestock Watering, Irrigation and Aquatic Biota 61
  • 83. APPENDICES 62
  • 84. Appendix I Questionnaires for the project on the use of nutrient enriched water for growing food crops in the Ngwerere river catchment and at the Kafue Lagoon AreasThis questionnaire is part of a research project looking at the use of nutrient enriched water ofthe Ngwerere River for growing food crops and to assess how this can contribute to povertyalleviation. The information collected will be kept with strict confidentiality and used strictly forthe development of the community.Dear RespondentKindly answer the following questions. Do not reveal your name.INSTRUCTIONSWhere options are given circle the letter representing the option you choose.Write answers to questions in the spaces provided where there are no options given.Section A: GeneralDemographic information on households using the nutrient enriched water1) Farmer’s sex a) Female b) Male2) Age a) 15-25 b) 26-35 c) 36-45 d) Above 453) Academic qualifications a) Primary b) Secondary c) College/University d) None e) Other, specify……………………………………………………………4) Marital status a) Single b) Married c) Separated d) Divorced e) Widowed5) Number of children………………….Dependants………………………………..6) Number of members of household above 16 years ………………………………7) Total household size ……………………………………………………………...8) Employment status a) Formal b) Informal 63
  • 85. c) Unemployed9) Main occupation of farmer ………………………………………………………..10) Second occupation of farmer ………………………………………………………11) Main source of household income…………………………………………………………………………………………12) Alternative sources…………………………………………………………………………………………Section B: Agricultural PracticeProvide the following information for each irrigated field under the control of the farmer:If the farmer has more than one irrigated plot at different locations consider only the mostimportant. If a single plot is divided into several fields and more than one is irrigated, giveinformation for each field within the plot.1. Field Identification2. Approximate size of field (acres)3. Distance of land from house (miles)4. How many years have you farmed the field5. Does flooding occur 1. Never 2. In some years 3. Every year6. How many months a year is field flooded7. Do you continue to farm the field on raised bedswhen it is flooded? (Yes/No/NA)8. For how much of the year do you irrigate crops onthis field? 1. All through the year 2. Indicate the months9. How long has the field been cultivated underirrigation? [if known] (Years)10. Current tenure? 1. Freehold 2. Leasehold 3. Communal 4. Traditional11. Amount paid in rent12. Terms if cash rent (months)13. Terms if share cropped14. Who often does the irrigation? (Male or Female)13) Do you farm the land in partnership with another person or persons? Yes/No14) If the answer is ‘yes’ what is the contribution from the partners and how is the profit shared?Contributions: Self (%) Partner 1 (%) Partner 2 (%)1. Land2. Labour3. InputsShare of Profits 64
  • 86. Section C: Water Management15) Water Source i. Main supply (pipe) ii. Stream/river (perennial) iii. Stream pool iv. Shallow dug out v. Stream pools and later dug outs vi. Deep well of borehole vii. Natural pool/pond viii. Gutter ix. Other (specify) ……………………………………………………16) Conveyance from source to field i. Manually bucket/watering can ii. Pumped iii. Manually but occasional pump hire iv. Stand-pipe and hoses v. Other specify17) Field application method. More than one method may be circled 1. From watering can/bucket/tin filled at the source 2. From watering can/bucket/tin filled from field-side oil drum 3. From hose pipe without sprinkler 4. From hose and shallow held in the hand 5. From hose and mounted sprinkler 6. Other (specify) …………………………………………….18) How much water do you use for irrigation? ……………………………………...19) Do you think this is enough? Yes/No20) If ‘No’, what do you think should be done to increase the amount of water?……………..……………………………………………………………………………21) Does your access to water limit the area that you cultivate in any part of the year because a. The source may dry up b. Requires too much effort to carry more water c. No22) Do you think your yield is reduced because you cannot apply enough water to your crop? Yes/No23) Would you drink the water you use for irrigation? Yes/No24) If [20] is ‘No’, why ……………………………………………………………….25) Does water quality influence your choice of irrigation crops? Yes/No26) If the quality or quantity of water has been a significant problem what efforts have you made, individually or jointly with others, to improve the situation? ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… …………………………………………………27) Do you pay for water? Yes/No 65
  • 87. 28) Are you able to apply much water, as you would like to your crops? Yes/No29) If ‘No’ what is it that limits the amount you apply? 1. Cost of labour to carry or apply water 2. Cost of water tariff 3. Cost of pump hire or operation 4. The work is too hard 5. Not enough available at the source 6. Water quality any fear of crop damage 7. Other (specify) ……………………………………………30) Have you received any formal training in vegetable production? Yes/No31) If ‘Yes’ describe training, when ……………and where …………………………32) If answer was ‘No’ how did you learn able irrigated vegetable cultivation?…………………………………………………………………………………………33) Are some of your crops stolen from your field? Yes/No34) If ‘Yes’ is this 1. A major problem 2. 2. Minor problemSection D: Crop marketing35) How do you sell the crops? 1. Take produce to a market (where) …………………….. 2. Individual consumers buy from the field (where do they came from)………………… 3. Traders buy from the field (where do they came from) …. 4. Other (specify) ………………………………...36) Do you market your produce as: 1. An individual? 2. A member of an informal group? 3. A member of a co-operative?37) How much do you earn from the sale of the crops?…………………………… (a) Per day ………. (b) Per Week …………… (d) Per months ……………..38) Are you satisfied with the income?…………………………..………….…………….39) What problems do you face in selling the produce?……………………………………………………………………………………………………………………………………………………………………………………Section E: Public health issues40) Do you see the use of this type of water as a threat to human health? Yes/No41) Do you want an improvement in the sanitation of the stream so that the water can be safer for both the producer and the consumer? Yes/No42) If asked to pay for this improvement would you agree? Yes/No43) Have you or any one of your household suffered from any illness related to the use of the water or crops grown using the same water in the last 12 months? Yes/No44) If ‘Yes’, how frequent were these illnesses? 1. Few times 2. Sometimes 66
  • 88. 3. OftenWhat type of disease(s) ……………………………………………………………….Section G: Attitudes toward organizations responsible for delivery of water relatedservices.45) Are you aware of any organisation/community project/association, which addresses water issues in the area? (if answer is ‘No’, skip to Next section) Yes/No46) If ‘Yes’, are you a member of any? Yes/No: If ‘Yes’, which one?…………………………………………………………………………………………47) Do you think most of the strategies put across have been beneficial to you in terms of being adequately provided with adequate and safe water?…………………………………………………………………………………………48) Do you relate very well with programme/project implementers or is this done through representative members? Yes/No. Reason?…..……………………………………………………………………………………..49) Are you satisfied with the current performance of the organisation/project/association? 1. Satisfied 2. Not satisfied50) If ‘not satisfied’ with the performance what improvements do you want to see?……………………………………………………………………………………………………………………………………………………………………………………Section H: Perceived problems and possible solutions51) Do you have plans to expand the acreage? 1. This year 2. Next year 3. Sometime 4. Never52) Is the growing of crops using nutrient enriched water an activity you want to continue with? Yes/No53) Do you experience any harassment because you are growing crops in this location? Yes/No54) If ‘Yes’ from whom? ………………………………………………………………55) What problems have you faced so far in the following areas as far as the use of the nutrient enriched water is concerned? a) Quantity of water…………………………………………………………… b) Quality of water…………………………………………………………….. c) Maintenance of infrastructure (if any)……………………………………… d) Paying for water services (if any)………………………………………… e) Accessing water…………………………………………………………... f) Dialogue with implementers and relevant authorities…………………….56) What are your suggestions in each of the above areas? a) ……………………………………………………………………………… b) ……………………………………………………………………………… c) ……………………………………………………………………………… 67
  • 89. d) ……………………………………………………………………………… e) ……………………………………………………………………………… f) ……………………………………………………………………………… Field identification …………………………………………………………..Crop S O N D J F M A M J J A Area Yield Unit Price per unit (acres) 68
  • 90. Appendix IIWastewater treatment and quality criteria for irrigation (State of California 1978)Treatment level Coliform Limits Types of usePrimary Surface irrigation of orchards and vineyards, Fodder, fiber, and seed crops.Oxidation and disinfection , Pasture for milking animals; landscape <23/100ml impoundments; Landscape irrigation (golf courses, cemeteries, etc.) < 2.2/100 ml Surface irrigation of food crops (no content between water and edible portion of crop)Oxidation, Coagulation, < 2.2/100ml max. =23/100ml Spray irrigation of food cropsclarification, filtration Landscape irrigation (parks,And disinfections playgrounds, etc.)Source: Pettygrove and Asano 1985.a. The turbidity of filtered effluent cannot exceed an average of two turbidity units during any 24-hour period. 69
  • 91. Appendix IIIIrrigation Water Quality GuidelinesGuidelines for Interpreting Water Quality for IrrigationPotential Irrigation Problem units None Slight to Moderate SevereSalinity (affects crop water Ds/m < 0.7 0.7 – 3.0 3.0availability) ECw Or TDS Mg/1 <450 450 – 2,00 > 2,000Infiltration (affects infiltration rate ofwater into the soil; evaluate usingECw and SAR together)SAR=0- 3 and ECw = 3-6 =ds/m >0.7 0.7 – 0.2 < 0.2=6-12 =ds/m >1.2 1.2 – 0.3 < 0.3=12-20 =ds/m >1.9 1.9 – 0.5 < 0.5=20-40 =ds/m >2.9 2.9 – 1.3 < 1.3 =ds/m 0 >5.0 5.0 – 2.9 < 2.9Specific ion toxicity (affects sensitivecrops) sodium (Na) Surface irrigation SAR <3 3-9 >9 Sprinkler irrigation Me/l <3 >3Chloride (Cl) Surface irrigation Me/l <4 4 – 10 >10 Sprinkler irrigation Me/l <3 >3Boron (B) Mg/1 <0.7 0.7 – 3.0 >3.0Trace elements (see Table B.2)Miscellaneous effects (affectssusceptible crops) Nitrogen (NO3-N) Mg/l <5 5 - 30 >30Bicarbonate (HCO3) (overheadsprinkling only) Me/l <1.5 1.5 – 8.5 >8.5 pH Normal range 6.5 – 8.4Ecw means electrical conductivity, a measure of water salinity reported in decisiesmens per meter at 25o C(ds/m)or in milliohms per centimeter (nmho/cm). Both are equivalent. TDS means total dissolved solids, reportedin milligrams per liter (mg/l).SAR sodium adsorption ratio.1 me/1 = 1 milliequivalent per liter, where 1 me Na = 11 mg; 1 me Cl = 17mg; 1 me HCO3 = 31 mg.Source; Adapted from Ayers and Westcot 1985, to which he reader may refer for detailed assumptions in andjustification of the guidelines presented above. 70
  • 92. Appendix IVRecommended Maximum Concentrations of Trace Elements in Irrigation Water Element Recommended Remarks maximum concentration (mg/1) AL 5.0 Can cause nonproductivity in acid soils (pH <5.5), but more alkaline soils at pH > 7.0 will precipitate the ion and eliminate any toxicity. As 0.10 Toxicity to plants varies widely, for example, < 0.5mg/1 for Lemon, 1.0 mg/1 for rice. B 0.5 - 15 Toxicity to plants varies widely: for example, < 0.5 mg/1 for lemon, 1.0 mg/1 for wheat, 6.0 mg/1 for tomato, and 15mg/1 for cotton. Be 0.10 Toxicity to plants varies widely, ranging from 5.0 mg/1 for kale to 0.5 mg/1 for bush beans. Cd 0.01 Toxic to beans, beets, and turnips at concentrations as low as 0.1 mg/1 in nutrient solutions. Conservative limits recommend because of its potential to accumulate in plants and soils to concentrations that may harm humans. Co 0.05 Toxic to tomatoes at 0.1 mg/1 in nutrient solution. Tends to be inactivated by neutral and alkaline soils Cr 0.10 Not generally recognized as an essential growth element. Conservative limits recommend because of lack of knowledge about its toxicity to plants. Cu 0.20 Toxic to a number of plants at 0.1 to 1.0 mg/1 in nutrient solutions. F 1.0 Inactivated by neutral and alkaline soils. Fe 5.0 Not toxic to plants in aerated soils, but can contribute to soil acidification and loss of availability of essential phosphorus and molybdenum. Overhead sprinkling may result in unsightly deposits on plants, equipment, and buildings Li 2.5 Tolerated by most crops up to 5.0mg/1; mobile in soil. Toxic to citrus at low concentration (<0.075mg/1). Acts similarly to boron. Mn 0.20 Toxic to a number plants at a few tenths to a few mg/1, but usually only in acid soils. Mo 0.01 Not toxic to plants at normal concentrations in soil and water. Can be toxic to livestock if forage is grown in soils with high concentrations of available molybdenum. Ni 0.20 Toxic to a number of plants at 0.5mg/1; reduced toxicity at neutral or alkaline pH Pb 5.0 Can inhibit plant cell growth at very high concentrations. Se 0.02 Toxic to plants at concentrations as low as 0.025mg/1 and toxic to livestock if forage is growth in soils with relatively high levels off added selenium. An essential element to animals but in very low concentrations. V 0.10 Toxic to many plants at relatively low concentrations. Zn 2.0 Toxic to many plants at widely varying concentrations; reduced toxicity at pH 6.0 and fine-textured or organic soils.This is not an exhaustive list of the effects of all trace elements found in wastewater, especially if industrial wastes aredischarged directly into it. If industrial wastes are found in the wastewater, the trace elements contribute need to be identifiedand information obtained about their effects on a site-specific basis.The maximum concentration is based on a water application rate consistent with good irrigation practices (10,000m3/ha/yr). Ifthe rate greatly exceeds this, the maximum concentrations should be adjusted downward accordingly. No adjustment should bemade for application rates less than 10,000 m3/ ha/yr. The values given are for water used on a continuous basis at one site.Source: Ayers and Westcot 1985. 71
  • 93. Appendix VConstituents of concern in wastewater treatment and irrigation using reclaimedmunicipal wastewaterConstituents Measured parameters Reason for concernSuspended solids Suspended solids, Suspended solids can lead to the development of sludge including volatile and deposits and anaerobic conditions when untreated fixed solids wastewater is discharged into the aquatic environment. Excessive amounts of suspended solids cause plugging in irrigation systems.Biodegradable BOD, COD Composed principally of proteins, carbohydrates, and fats.organics If discharged into the environment, their biological decomposition can lead to the depletion of dissolved oxygen in receiving waters and to the development of septic conditions.Pathogens Indicator organisms, Communicable diseases can be transmitted by the total and fecal coliform pathogens in wastewater: bacteria, viruses, and parasites. bacteriaNutrients Nitrogen, Phosphorus, Nitrogen, phosphorus and potassium are essential nutrients potassium for plant growth, and their presence normally enhances the value of the water for irrigation. When discharged into the aquatic environment, nitrogen and phosphorus can lead to the growth of undesirable aquatic life. When discharged in excessive amounts on land, nitrogen can also lead to groundwater pollutionStable (refractory) Specific compounds These organics tend to resist conventional methods oforganics (e.g., phenols, wastewater treatment. Some organic compounds are toxic pesticides, chlorinated in the environment, and their presence may limit the hydrocarbons) suitability of the wastewater for irrigation. 72
  • 94. Appendix VIQuestionnaire resultsSection A: GeneralDemographic information on households using the nutrient enriched water1) Farmer’s sex (see tables below)2) Age (see tables below) Table 1a: Ages of Farmers in Ngwerere River AreaNgwerere Area Gender Males % Females %Age15-25 7 17 -26-35 15 36 1 236-45 6 14 2 5Above 45 6 14 5 12Totals 34 81% 8 19% Table 1b: Ages of Farmers in Kafue Lagoon AreasKafue Lagoon Gender Males % Females %Age15-25 - - - -26-35 2 7 3 1036-45 2 7 4 13Above 45 8 27 11 36Totals 12 41% 18 59%3) Academic qualifications: (see table below)• Primary• Secondary• College/University• NoneTable 2a: Ngwerere River Area (Academic qualification, marital status and employmentstatus) Single % Single Married % Married Divorced % Divorced Widowed % WidowedPrimary 4 10 18 43 - -Secondary 5 12 8 19 - -College 1 2None 1 2 4 7 1 2 1 2Totals 11 26 30 69 1 2 1 2 Single % Single Married % Married Divorced % Divorced Widowed % WidowedEmployed - - 1 2 - - -Unemployed 11 26 28 67 1 2 1 2Totals 11 26 29 69 1 2 1 2 73
  • 95. Table 2b: Kafue Lagoon Areas (Academic qualification, marital status and employment status) Single % Single Married % Married Divorced % Divorced Widowed % WidowedPrimary 3 10 9 30 1 3 4 14Secondary - 5 17College - - - -None 4 13 4 13Totals 3 10 18 60 1 3 8 27 Single % Single Married % Married Divorced % Divorced Widowed % WidowedEmployed - - - -Unemployed 3 10 60 1 3 8 27Totals 3 10 60 3 8 27 4) Marital status (see table above) • Single • Married • Separated • Divorced • Widowed 5) Number of children………………….Dependants……………………………….. 6) Number of members of household above 16 years ……………………………… 7) Total household size ……………………………………………………………... 8) Employment status (see table above) • Formal • Informal • Unemployed 9) Main occupation of farmer: (see table below) Table 3a: Ngwerere River Areas Gardening % Farming % Others % Main occupation 35 83 3 7 4 10 Second occupation 3 7 - - 39 93 Table 3b: Kafue Lagoon Areas Business/ Selling Gardening % Farming % piece work % Keeping cattle % charcoal % Others %Mainoccupation 21 70 2 7 3 10 4 13Secondoccupation 1 3 1 3 - - 1 3 1 3 26 87 10) Second occupation of farmer: (see table above) • Main source of household income of farmers in Kafue Lagoon Areas: gardening, selling of vegetables and sugar canes 74
  • 96. • Main source of household income of farmers in Ngwerere River areas: gardening and selling of vegetables11) Alternative sources of income for farmers in: • Kafue Lagoon Areas: gardening, selling of vegetables and sugar canes • Ngwerere River Areas: rental from houses, business and piece of work, gardening, selling of pesticides and vegetables.Section B: Agricultural Practice12) Do you farm the land in partnership with another person or persons?• Yes: 5% of the respondents’ farm in partnership with either the husband and the friend in Ngwerere River Area. The partnering is 50% each.• No: partnering of farmers in Ngwerere River is at (95%) and Kafue Lagoon Areas (100%)13) If the answer is ‘yes’ what is the contribution from the partners and how is the profit shared?Contributions: Self (%) Partner 1 (%) Partner 2 (%)1. Land2. Labour 50% 50%3. Inputs 50% 50%Share of Profits 50% 50%Section C: Water Management14) Water Source• Stream/river (perennial) - 88% use stream and 12% used both stream and hand dug out wells in Ngwerere Areas• Gutter – from NCZ discharge canal, Shikowse stream and Lee Yeast effluent canal15) Conveyance from source to field• Manually bucket/watering can - Manually using bucket/watering can (88%) in Kafue Lagoon Area• Manually bucket/watering can - Manually using bucket/watering can (93%) and 7% use engine/pump in Ngwerere River Areas16) Field application method. More than one method may be circled• From watering can/bucket/tin filled at the source – Manually bucket/watering can - Manually using bucket/watering can (88%) and engine/pump and hose pipe (12%) in Ngwerere areas17) How much water do you use for irrigation?• 20, 18 or 10 litres containers are used to irrigate the field crops; 20-litre container per 20 square meters - Ngwerere River Areas18) Do you think this is enough?• Yes (93%); No (7%)- Ngwerere River Areas19) If ‘No’, what do you think should be done to increase the amount of water? 75
  • 97. • More water should be released20) Does your access to water limit the area that you cultivate in any part of the year because• The source may dry up• Requires too much effort to carry more water21) Do you think your yield is reduced because you cannot apply enough water to your crop? Yes/No22) Would you drink the water you use for irrigation?• No (100%)23) If [20] is ‘No’, why?• The water is dirty (Ngwerere River and Kafue Lagoon Areas 100%24) Does water quality influence your choice of irrigation crops?• No – the water is good for irrigating the crops (100% at Kafue Lagoon Areas and Ngwerere Area)25) If the quality or quantity of water has been a significant problem what efforts have you made, individually or jointly with others, to improve the situation?26) Do you pay for water?• No (100% at Kafue Lagoon Areas and Ngwerere Area)27) Are you able to apply much water, as you would like to your crops?• Yes28) Are able to apply as much water as you would like to your crops?• Yes (100% at Kafue Lagoon Areas and Ngwerere Area)29) If ‘No’ what is it that limits the amount you apply?• Does not apply to all the study areas30) Have you received any formal training in vegetable production?Kafue Lagoon Areas• None received any training on how to grow crops. The farmers learnt how to grow crop and vegetables from parents, friends, through experience etc.Ngwerere River Areas• 83% of the farmers have not received any type of training. Learnt how to grow crops from either parents, friends, through experience, worked on a farm, and from school• 17% of the farmers have received some training in growing of agricultural crops from various institutions e.g. FAO Agricultural Extension Officers, Chamba Valley cooperative, Kasisi Training Centre, Kafue, Chamba Valley Partnership Forum. One farmer had only acquired skills in citrus fruit farming and rearing of animals.31) If ‘Yes’ describe training, when ……………and where …………… (see above)32) If answer was ‘No’ how did you learn able irrigated vegetable cultivation? (see above)33) Are some of your crops stolen from your field? 76
  • 98. • Yes34) If ‘Yes’ is this• A major problem because crops are uprooted by thieves• Minor problemSection D: Crop marketing35) How do you sell the crops?• Take produce to Soweto, Chaisa, Ngombe, Chipata, Kabanana, Kaunda Square and Katambalala markets (69%)• Individual consumers buy from the field: come from surrounding areas (12%)• Traders buy from the field: come from surrounding areas 14%• Other (specify) Fresh Mark (5%).36) Do you market your produce as:• An individual?- yes• A member of an informal group?- yes• A member of a co-operative?- yes37) How much do you earn from the sale of the crops?Table 4a: Farmers’ income in Kafue Lagoon and Ngwerere River Areas Amounts in Zambian Kwacha Per plot Per day Per week Per year Per 50 kg bagKafue 100, 000 8 000 - 60 000 8 000 – 500 000 800 000-1, 000, 000 K4 000 – K10 000LagoonAreasNgwerere K30 000 – 40 K5, 000-K40, 000 K15 000 - K400 000 - K5000 – K10 000river Area 00038) Are you satisfied with the income?• Yes• No39) What problems do you face in selling the produce?• The crops may rot or get spoilt or the agents overchargeSection E: Public health issues40) Do you see the use of this type of water as a threat to human health?• Yes (26%)- Ngwerere River area• No (74%)- Ngwerere River area41) Do you want an improvement in the sanitation of the stream so that the water can be safer for both the producer and the consumer?• Yes- Ngwerere River area• No- Ngwerere River area 77
  • 99. 42) If asked to pay for this improvement would you agree?• Yes• No43) Have you or any one of your household suffered from any illness related to the use of the water or crops grown using the same water in the last 12 months? Yes/No44) If ‘Yes’, how frequent were these illnesses?• Few times (5%)- Ngwerere River area• Sometimes (12%)- Ngwerere River area• Often (24%)- Ngwerere River area• No (49%)- Ngwerere River area• Yes (10%)- Ngwerere River areaWhat type of disease(s): malaria, bilharzias and diarrhoeaSection G: Attitudes toward organizations responsible for delivery of water relatedservices.45) Are you aware of any organisation/community project/association, which addresses water issues in the area? (if answer is ‘No’, skip to Next section) Yes/No46) If ‘Yes’, are you a member of any? Yes/No: If ‘Yes’, which one?…………………………………………………………………………………………47) Do you think most of the strategies put across have been beneficial to you in terms of being adequately provided with adequate and safe water?…………………………………………………………………………………………48) Do you relate very well with programme/project implementers or is this done through representative members? Yes/No. Reason?…..……………………………………………………………………………………..49) Are you satisfied with the current performance of the organisation/project/association? 1. Satisfied 2. Not satisfied50) If ‘not satisfied’ with the performance what improvements do you want to see?……………………………………………………………………………………………………………………………………………………………………………………Section H: Perceived problems and possible solutions51) Do you have plans to expand the acreage? 1. This year 2. Next year 3. Sometime 4. Never52) Is the growing of crops using nutrient enriched water an activity you want to continue with? Yes/No53) Do you experience any harassment because you are growing crops in this location? Yes/No54) If ‘Yes’ from whom? ……………………………………………………………… 78
  • 100. 55) What problems have you faced so far in the following areas as far as the use of the nutrient enriched water is concerned? a. Quantity of water…………………………………………………………… b. Quality of water…………………………………………………………….. c. Maintenance of infrastructure (if any)……………………………………… d. Paying for water services (if any)………………………………………… e. Accessing water…………………………………………………………... f. Dialogue with implementers and relevant authorities…………………….56) What are your suggestions in each of the above areas? a. ……………………………………………………………………………… b. ……………………………………………………………………………… c. ……………………………………………………………………………… d. ……………………………………………………………………………… e. ……………………………………………………………………………… f. ………………………………………………………………………………Field identification …………………………………………………………..Table 5a: Crops grown in Ngwerere River Area, yields, unit and price per unitCrop Months S O N D J F M A M J J A Area (acres) Yield Unit Price per unit (Kwacha)Cabbage 50kg sack 20000-30000 per head 1000Tomato 1 acre 2-6 boxes 1 box 10000-70000Spinach 0.25 ha 3 bags 50-75kg 40000-60000Sweet potato leavesMupilu 1 acre - 0.25 ha 2 - 8 bags 50 kg sack 15000-40000Nchembele 1 acre - 0.25 ha 4-6 bags 50 kg sack 15000-30000Chinese cabbage 0.25 acres - 0.5 5-9 bags 50 kg sach 30000 acreLettuce 0.25 acres 10 bags 50 kg sack 20000Lettuce per head 500Onion 0.5 ha 10kg porch 35000Onion 1 acre 1 bag 50 kg 15000Rape 0.25 acre - 0.25 ha 6-12 bags 50kg sack 15000-60000Carrot 0.25 -0.5 acre 5-9 bags 300 kg 2000-2500/kgGreen pepper per kg 1500Potatoes 4 bags 50 kg 48000Pumpkin leaves 15meters*20meters 8*50kg 50 kg sack 15000-35000 bagsOkra 1 acre 1 bag 50 kg sack 7000Maize 1 acre 10 cobs @ K3500 79
  • 101. Table 5b: Crops grown in Kafue Lagoon Area, yields, unit and price per unit MonthsCrop S O N D J F M A M J J A Area (acres) Yield Unit Price per unit (kwacha)Cabbage 50kg sack 20000-30000Tomato 0.25-1.5 acre 2-10 boxes 1 box 5000-25000Mupilu 1 acre - 0.25 ha 2 - 8 bags 50 kg sack 15000-40000Chinese cabbage 0.25 acres - 0.5 5-9 bags 50 kg sach 7000 acreOnion 1 acre 1 bag 50 kg 15000Rape 0.25 acre - 0.25 ha 1-2 bags 25-50kg 5000-35000 sackPumpkin leaves 0.25 acre 6 bags 50 kg sack 5000-10000Chikolowa 50 kg sack 18000CassavaBananas per bunch 2000GuavaBeans per bundle 500Sugar cane 1 acre 50 bundles Portion 8000 per portionMaize 1 acre 200-500 per 300 per cob cob 80
  • 102. Appendix VIIAnalyzed water quality data from Ngwerere River sampling points N1Ngwerere Area 0 1 5 6 9 19 20Sampling Date 07.7.04 08.7.04 12.7.04 13.7.04 16.7.04 04.8.04 05.8.04 Average SDpH 8.74 8.93 8.6 8.43 7.46 7.9 7.25 8.2 0.7Conductivity 601 613 567 586 583 610 603 595 17Water Temperature 17.5 18.3 18.3 17.4 18.1 19.5 20.4 19 1Salinity 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.00Magnesium (mg/l) 35.52 53.76 26.9 29.76 34.56 30.4 24.2 34 10Calcium (mg/l) 89.6 80 72 83.2 78.4 36 46 69 20Sulphate (mg/l) 33.8 29.2 28.2 39.4 32.3 33 4Total Nitrogen (as N mg/l) 10.8 0.96 4.16 4.075 5 4Total Phosphates (as PO4-P mg/l) 1.79 4.96 2.39 2.24 3.94 2.14 2.47 3 1Ammonia (as NH4-N mg/l) 4.39 4.47 3.83 3.18 4 1Biochemical Oxygen Demand (O2 mg/l) 19 18 28 18 15 24.5 16 20 5Chemical Oxygen Demand (O2 mg/l) 96 96 66 41 61 60.5 37.5 65 23Total Suspended Solids (mg/l) 114 120 50 36.5 80 43Bicarbonates (as CaCO3 mg/l) 340 320 314 311 321 13Nitrates (as NO3-N mg/l) 5.2 0.01 0.01 0.01 11.86 0.01 0.01 2 5Iron (mg/l) 0.38 0.67 3.3 0.9 0.24 1 1Sodium (mg/l) 239 225.3 227 222.2 248.7 232 11E.coli (#/100ml) 120 96 6,200 2,200 2,200 500 520 1691 2185Faecal coliforms (#/100ml) 12,000 9,000 9,300 4,000 3,100 18000 17500 10414 5890Faecal Streptococci (#/100ml) 900 70 500 1,000 220 8000 8500 2741 3781 N2 0 1 5 6 9 19 20 07. 7.04 08.7.04 12.7.04 13.7.04 16.7.04 04.8.04 05.8.04 Average SDpH 8.5 8.4 7.5 8.4 7.7 8.0 7.1 7.9 0.6Conductivity 567 576 576 571 556 590 564 571 11Water Temperature 16.5 16.3 16.3 15.6 16.4 18.2 19.2 17 1Salinity 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.00Magnesium (mg/l) 44.2 22.08 38.4 29.76 43.2 23.1 27.9 33 9Calcium (mg/l) 76.8 100.8 78.4 89.6 72 57.6 48 75 18Sulphate (mg/l) 34.3 24.7 28.2 27.8 31.9 29 4Total Nitrogen (as N mg/l) 9.6 0.94 4.375 3.975 5 4Total Phosphates (as PO4-P mg/l) 1.83 4.94 2.4 2.44 4.25 1.35 2.28 3 1Ammonia (as NH4-N mg/l) 3.75 3.91 3.525 3.16 3.6 0.3Biochemical Oxygen Demand (O2 mg/l) 24 30 20 15 5 29.5 19.5 20 9Chemical Oxygen Demand (O2 mg/l) 98 96 75 44 62 51 45 67 23Total Suspended Solids (mg/l) 98 90 48.5 8 61 42Bicarbonates (as CaCO3 mg/l) 356 310 318 337 330 21Nitrates (as NO3-N mg/l) 5.5 0.01 0.01 0.01 11.68 0.01 0.01 2 5Iron (mg/l) 0.01 0.03 1.3 0.01 0.26 0.3 0.6Sodium (mg/l) 223.6 225.3 212.8 206.6 226.3 219 9E.coli (#/100ml) 100 100 1,000 4,000 1,200 453 470 1046 1368Faecal coliforms (#/100ml) 4,000 5,000 1,700 8,500 2,000 12350 15000 6936 5179Faecal Streptococci (#/100ml) 400 388 100 1,500 210 5500 7500 2228 3010 81
  • 103. N3 0 1 5 6 9 19 20 07.7.04 08.7.04 12.7.04 13.7.04 16.7.04 04.8.04 05.8.04 Average SDpH 9.5 9.8 8.9 10.6 8.9 7.8 8.05 9 1 423 418Conductivity 440 410 412 411 413 418 11Water Temperature 17 17.8 18.4 18.1 18.1 19.5 21.4 19 1Salinity 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.00Magnesium (mg/l) 55.5 60.8 26.9 29.76 43.2 24.55 48.1 41 14Calcium (mg/l) 54.4 44.16 56 41.6 71.2 61.6 12.4 49 19Sulphate (mg/l) 28.7 17 19.8 20.8 26.4 23 5Total Nitrogen (as N mg/l) 1.12 1.16 4.385 0.29 2 2Total Phosphates (as PO4-P mg/l) 0.2 0.01 0.26 0.28 1.82 1.355 2.145 1 1Ammonia (as NH4-N mg/l) 0.12 0.03 3.475 0.18 1 2Biochemical Oxygen Demand (O2 mg/l) 14 6 15 4 3 29.5 20 13 10Chemical Oxygen Demand (O2 mg/l) 96 96 63 53 57 35 44.5 64 24Total Suspended Solids (mg/l) 104 100 23 15 61 48Bicarbonates (as CaCO3 mg/l) 276 250 318 217 265 43Nitrates (as NO3-N mg/l) 0.01 0.01 0.01 0.01 10.83 0.01 0.01 2 4Iron (mg/l) 0.08 0.01 1.7 2.3 0.21 1 1Sodium (mg/l) 216.6 229.4 212.3 207.6 227.3 219 9E.coli (#/100ml) 90 90 400 500 1,000 313 175 367 320Faecal coliforms (#/100ml) 340 380 1,200 1,400 1,200 7850 9000 3053 3708Faecal Streptococci (#/100ml) 70 10 400 300 190 1385 1805 594 707 82
  • 104. Appendix VIIIAnalyzed water quality data from Kafue Lagoon AreaKafue Lagoon July 2004 Shikoswe Shikoswe Lee Yeast Lee YeastSampling Date 08.07.04 20.07.04 08.07.04 20.07.04pH 10.89 11.19 11 11.87Conductivity 343 390 5600 6420Temperature 19.4 20.1 16.3 18.3Salinity 0.01 0.01 0.3 0.34Sulphate (mg/l) 29.2 -Total Nitrogen (as N mg/l) - -Total Phosphates (as PO4-P mg/l) - -Ammonia (as NH4-N mg/l) 3.32 4.598 2.85 2.180Biochemical Oxygen Demand (O2 mg/l) - -Chemical Oxygen Demand (O2 mg/l) - -Total Suspended Solids (mg/l) - -Bicarbonates (as CaCO3 mg/l) 198 230 328 334Nitrates (as NO3-N mg/l) - -Iron (mg/l) 0.54 0.60 1.43 1.11Sodium (mg/l) 989.5 160.9Lead (mg/l) <0.01 <0.01 <0.01 0.08Copper (mg/l) <0.01 <0.01Cadmium (mg/l) <0.002 <0.002Mercury (mg/l) <0.0002 <0.0002Zinc (mg/l) <0.001 <0.001Boron (mg/l) <0.5 <0.5Bacteriological ResultsE.coli (#/100ml) 5,000 1200 76 2000Feacal coliforms (#/100ml) 8,000 3300 8,000 4000Feacal Streptococci (#/100ml) 96 800 120 1000Total coliforms (#/100ml) 4500 7000 83
  • 105. Appendix IXAnalyzed sediments from Ngwerere area from Ngwerere sampling pointsLab No. 40448 40452 40449 40453 40450 40454Sample Id N1 N1 N2 N2 N3 N3ParameterSampling Date 07.07.2004 13.07.2004 07.07.2004 13.07.2004 07.07.2004 13.07.2004Lead (mg/kg) 0.13 1.38 0.5 1.57 1.17 0.62Copper (mg/kg) 0.16 7.51 0.33 1.85 1.85 1.27Cadmium (mg/kg) <0.002 <0.002 <0.002 <0.002 <0.002 <0.002Mercury (mg/kg) <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.0002Zinc (mg/kg) 0.969 8.8 1.266 1.838 1.636 0.185Iron (mg/kg) 75 1,596.30 282 480.93 1,310 312.63 84
  • 106. Appendix XAnalyzed sediments from Kafue Lagoon AreaLab No. 40451 40455 40456Sample Id Shikoswe Shikoswe LYParameterSampling Date 08.07.2004 20.07.2004 20.07.2004Lead (mg/kg) - 0.82 0.85Copper (mg/kg) 0.04 58 1.51Cadmium (mg/kg) <0.002 <0.002 <0.002Mercury (mg/kg) <0.0002 <0.0002 <0.0002Zinc (mg/kg) <0.001 15.6 11.2Iron (mg/kg) 8.62 1,503 1,175 85
  • 107. Appendix IXBase flow index calculation for Ngwerere Estate WeirBASEFLOW INDEX CALCULATIONStation Number: 5016Name: Ngwerere River at Estate WeirTime-Series: Mean Daily FlowPeriod of analysis from: 1-Oct-1970 to 30-Sep-2004BFI calculated over whole periodNumber of days in period = 12389Number of days with data = 12226Number of days for BFI = 12152Total volume (mm/year) = 234.587Baseflow volume (mm/year) = 198.768BFI = 0.8473BFI in each hydrological year Year start Days Data Days BFI days Years Total (mm) Baseflow (mm) Surface runoff BFI Oct-70 365 365 360 Oct-70 168.266 146.637 21.629 0.8715 Oct-71 366 366 366 Oct-71 181.685 169.805 11.88 0.9346 Oct-72 365 365 365 Oct-72 155.835 139.143 16.692 0.8929 Oct-73 365 365 365 Oct-73 185.09 169.875 15.215 0.9178 Oct-74 365 365 365 Oct-74 202.398 186.673 15.725 0.9223 Oct-75 366 366 366 Oct-75 198.493 180.843 17.65 0.9111 Oct-76 365 365 365 Oct-76 192.981 178.909 14.072 0.9271 Oct-77 365 365 365 Oct-77 281.092 222.468 58.624 0.7914 Oct-78 365 365 365 Oct-78 546.066 476.88 69.186 0.8733 Oct-79 366 366 366 Oct-79 406.846 367.31 39.536 0.9028 Oct-80 365 365 365 Oct-80 535.992 467.806 68.186 0.8728 Oct-81 365 365 365 Oct-81 243.704 208.81 34.894 0.8568 Oct-82 365 365 365 Oct-82 203.039 187.343 15.696 0.9227 Oct-83 366 366 366 Oct-83 183.026 162.267 20.759 0.8866 Oct-84 365 365 365 Oct-84 240.364 218.739 21.625 0.91 Oct-85 365 365 365 Oct-85 321.747 244.184 77.563 0.7589 Oct-86 365 365 365 Oct-86 33.86 33.86 0 1 Oct-87 366 366 366 Oct-87 272.086 223.201 48.885 0.8203 Oct-88 365 365 365 Oct-88 88.673 76.294 12.379 0.8604 Oct-89 365 365 365 Oct-89 247.417 206.466 40.951 0.8345 Oct-90 365 365 365 Oct-90 318.628 296.212 22.416 0.9296 Oct-91 366 366 366 Oct-91 82.33 77.802 4.528 0.945 Oct-92 365 365 365 Oct-92 33.86 33.86 0 1 Oct-93 365 365 365 Oct-93 102.869 90.846 12.023 0.8831 Oct-94 365 365 365 Oct-94 166.894 146.879 20.015 0.8801 Oct-95 366 366 366 Oct-95 173.494 152.47 21.024 0.8788 Oct-96 365 365 365 Oct-96 253.931 195.273 58.658 0.769 Oct-97 365 365 365 Oct-97 402.35 314.597 87.753 0.7819 Oct-98 365 365 354 Oct-98 228.488 132.155 96.333 0.5784 Oct-99 366 253 243 Oct-99 188.72 151.968 36.752 0.8053 Oct-00 365 365 365 Oct-00 314.836 170.899 143.937 0.5428 Oct-01 365 365 365 Oct-01 251.368 224.648 26.72 0.8937 Oct-02 365 364 353 Oct-02 240.118 200.038 40.08 0.8331 Oct-03 336 287 250 Oct-03 158.25 145.608 12.642 0.9201 86
  • 108. Appendix XIICurrent national water quality standards in use in Zambia CONSTITUENT ZNBS*/DWA^ DWA^ Water Aid Zambia Permissible Limit Desirable Limit Adopted (mg/l) (mg/l) Standard (mg/l) Bacteriological A) Unpiped water Faecal coliforms (per 100ml) 0 Not specified HDW/TS^^: 10 Hand pump: 0 Total coliforms (per 100 ml) 20 Not specified N/A B) Piped water Faecal coliforms (per 100ml) 0 Not specified N/A Total coliforms (per 100ml) 0 Not specified N/A Arsenic 0.05 0.01 N/A Fluoride 1.5 0.7-1.1 1.5 Nitrate 10 5 N/A Nuisance elements Iron 1.0 Not specified 1.0 Magnesium 150 50 150 Taste/odour Unobjectionable Not specified UnobjectionableNote:*Zambia Bureau of Standards (ZS 190:1990)^ Department of Water Affairs (from The National Water Resources Master Plan, 1995)^^ HDW = Hand dug well with bucket and windlass; TS = traditional water source 87
  • 109. Appendix XIIIResults of effluents from Nitrogen Chemicals of Zambia (NCZ)Parameters Analysis ECZ Limit (point source)pH 7.35 6.0-9.0Cu, mg/L <0.02 1.5Pb, mg/L <0.24 0.5Zn, mg/L <0.017 10Co, mg/L <0.15 1.0Mg, mg/L 133.6 500Fe, mg/L 12.1 2.0Total solids, mg/L 1005 100Total Dissolved Solids, mg/L 729.5 3000Suspended Solids, mg/L 275.5 -Ca, mg/L 336.3 -Nitrates, mg/L 65.84 50Sulphate, mg/L 174.3 1500Phosphate, mg/L 0.079 6Chlorine, mg/L 21.2 800Sources: Sinkala et al (1996), Control of Aquatic Weed in the Kafue river Basin between Iteshi-teshi Dam andKafue Gorge (March 1996 – March 1997), (draft) Final Report 88
  • 110. Appendix XIVChemical analysis of effluents from Lee Yeast FactoryParameter Sample 1 Sample 2 ECZ SpecificationpH 7.3 4.1 6.0-9.0TH (mg/l) 348.57 159.91 -TS (mg/l) 6438 8768 100TDS (mg/l) 6382 8580 3000SS (mg/l) 56 188 -Cl- (mg/l) 434 44 800NO3- (mg/l) 0.13 0.04 50Free NH3 (mg/l) Nil Nil 10PO4- (mg/l) 0.42 0.05 6SO4- (mg/l) 0.75 900 1500Pb (mg/l) <0.41 <0.246 0.5Cu (mg/l) <0.011 <0.018 1.5Zn (mg/l) <0.016 <0.49 10Co (mg/l) <0.13 0.12 1.0Fe (mg/l) <0.11 13.63 2.0Cd (mg/l) <0.022 <0.024 -Ca (mg/l) 265.82 140.09 -Mg (mg/l) 82.75 19.82 -Total coliforms per 100ml 81818 - 25000Sources: Sinkala et al (1996), Control of Aquatic Weed in the Kafue river Basin between Iteshi-teshi Dam andKafue Gorge (March 1996 – March 1997), (draft) Final Report 89
  • 111. Appendix XVParameters used in quality testingTemperature:When the temperature of a waterway is raised, pollution occurs even though no nutrients have been added orremoved from the water. There are two principle effects to this phenomenon. Firstly, solubility of oxygendecreases with increasing temperatures. Secondly, the metabolic reaction of the micro-organisms increases withtemperature. An increase of temperature thus produces simultaneously, a decrease in the availability of dissolvedoxygen and an increase in the rate at which it is being consumed. This reduces a streams self-purificationcapacity and thus usually results in pollution. According to ECZ the temperature of effluents at the point of entry toreceiving water body should not exceed 40oC.pH:pH is a measure of the concentration of hydrogen ions. pH values for natural waters range from 5 to 9. Liketemperature pH also affects the chemical reactions of compounds and elements in a solution. For example theconversion of ammonium ions to free ammonia increases with an increase in pH as shown below;NH4+ = NH3+ H+Ammonia (NH3) is toxic to fish and other aquatic organisms. The pH can be used as a parameter for early warningof pollution in a water body.Conductivity:The conductivity of a solution is a measure of its ability to conduct an electrical current and approximates thenumber or concentration of ions on that solution. Since the nature of the electrolyte has minor influence on theconductivity, conductivity can therefore be used to estimate the total ionic concentration of a water sample, whichin most cases approximates the total dissolved solids. Total dissolved solids even when non-toxic and non-nutrient in nature will reduce oxygen solubility and therefore indirectly contribute to pollution.Total Suspended Solids:Suspended solids may cause pollution in a lot of ways.The presence of suspended solids hinders light from reaching photosynthetic organisms, so reducing oxygenproduction;If present in large quantities, suspended solids will increase the effective viscosity of the water and impair flow in awaterway thereby reducing the oxygen dissolution;When these solids settle they form a layer on the waterway bed through which oxygen penetration is very difficult,thus producing an anaerobic sediment layer. They also present an aesthetically unpleasant appearance;Finally, suspended solids consist of organic materials, which decompose slowly, releases soluble nutrients into thewater, thus exerting delayed oxygen demand.Biochemical Oxygen Demand (BOD):The Biochemical Oxygen Demand (BOD) is the amount of dissolved oxygen required for the completedecomposition of the biodegradable matter in a sample. The BOD test is used to determine the pollution strengthof domestic and industrial wastes in terms of oxygen that they will require if discharged into natural watercoursesin which aerobic conditions exist. In other words this test assesses the oxygen used up in the actual biologicalbreakdown of a waste sample, and is an effective laboratory simulation of the microbial self-purification process.The standard BOD test demands the incubation of a sample at 2oC for a period of 5 days and is abbreviated asBOD. In this period the BOD registered is virtually due to the breakdown of the major proportions of carbonaceousmatter. The biological degradation of biodegradable carbonaceous matter is complete after 20 days at 2oC.BOD2020 = 1.46 * BOD20The breakdown of nitrogen compounds starts after approximately 10 days and takes a long time. In the absence ofdissolved oxygen tests the BOD would give an indication of organic pollution in the water.Chemical Oxygen Demand (COD):The Chemical Oxygen Demand (COD) is the amount of oxygen taken up by a waste sample from potassiumdichromate after two hours of refluxing with concentrated sulphuric acid. The COD test, like the BOD test, is alsoused as a means of measuring the pollution strength of domestic and industrial wastes. In this test nearly all- 90
  • 112. organic matter is virtually completely oxidized. It thus gives an indication of the total oxygen demand of a wastesample. The ratio of the BOD to the COD is therefore a guide to the proportion of organic materials present in awaste sample, which are biodegradable.Dissolved Oxygen:Free dissolved oxygen is the essential reagent for aerobic processes. When aerobic organisms utilize organicnutrients, they consume dissolved oxygen at the same time. If the dissolved oxygen is not replenished to such anextent that total depletion occurs, aerobic processes stop giving way to the slow and malodorous anaerobicprocess. This implies that aquatic life, be it macro or micro-organisms cannot survive. The availability of freedissolved oxygen is thus the key factor limiting the self-purification capacity of a watercourse.When nutrient solutes (e.g. waste, sewage, etc.) enter a relatively unpolluted water course it accelerates the rateof oxygen depletion as most oxygen is then used in the breaking down of these nutrients by the aerobic bacteriaresulting in the low concentrations of dissolved oxygen. This therefore means a low concentration of dissolvedoxygen is an indicator of pollution.Ammonia/Nitrates:Ammonia as ammonium ions or as free ammonia is the most common occurring nitrogenous pollutant. It usuallystems from decaying organic matter, fertilizers and sometimes from geological formations. Because of its smell itis undesirable to water. It is also toxic to aquatic life in small concentrations. Its presence in a watercourse, ifstemming from organic matter, represents fresh pollution. The other problem of ammonia as a pollutant is that itexerts a very high oxygen demand for its complete oxidation as shown below.NH4 +2O = NO3 +2H + H2OFrom the above equation it is evident that the presence of nitrates is an indication that nitrogen pollution eitherfrom organic nitrogen compounds or inorganic compounds like fertilizers had taken place in a watercourse.Therefore in a watercourse one would expect the concentration of nitrates to increase as ammonia gets oxidized.Nitrates usually cause eutrophication, which is pollution of a watercourse by heavy organic growth (usually algae).This will produce an unsightly green slime-layer over the surface of the watercourse. Apart from this,eutrophication will cause the following problems:As photosynthesis involves the creation of organic matter from inorganic materials and so resulting in theproduction of large quantities of organic substances where very little or nothing existed before. When thesephotosynthetic organisms die off, their components become organic nutrients exerting an oxygen demand on awatercourse.In the absence of light, many types of algae consume oxygen and this may lead to serious deoxygenation at nightwith serious repercussions to aquatic life. Sometimes, when a thick algal blanket is produced, light may notpenetrate the lower layers of the blanket, so that even in the presence of light, algae in the lower levels are usingup oxygen.Phosphates:Phosphates usually stem from detergents, sewage, and sometimes-geological formation. Higher concentration ofphosphates, usually if present together with ammonia and nitrate, is an indication of pollution. Phosphates aspollutants are usually significant because they promote eutrophication (see also Nitrates)Faecal Coliforms:Faecal coliforms are not pathogenic themselves but their presence in water indicates the possible presence ofpathogens, usually of faecal origin. The absence of faecal coliforms indicates that faecal pollution is absent in awatercourse. Faecal coliforms are very suitable indicators because of the following reasons:Their presence is detected by relatively simple analytical proceduresThe analysis is not time consumingSince the number of coliforms is usually much greater than that of possible pathogens, there is a greater margin ofsafety provided.Cadmium (Cd)Cadmium, Cd, is a silvery-white soft metallic element that is highly toxic to marine and fresh water aquatic life.Many of its organic and inorganic salts are highly soluble. The presence of cadmium in the aquatic environment is 91
  • 113. of concern because it bio-accumulates. Cadmium has a low solubility under conditions of neutral or alkaline pHand highly soluble under acidic conditions, where toxic concentrations can easily arise from the dissolution ofcadmium from cadmium-plated materials.Cadmium is known to inhibit bone repair mechanisms, and is teratogenic, mutagenic and carcinogenic.Copper (Cu)Copper is an essential trace element for organisms but becomes toxic at higher concentrations. In general only thedissolved form is considered when the toxicity is evaluated. The toxicity of copper is regulated by hardness(calcium and magnesium), organic substances, other metal ions and pH. These substances either directly bindcopper in less toxic forms or are indicators of such binding compounds. Algae, especially blue-green, nitrogenfixing algae, are very susceptible to Cu. Copper is bioaccumulated in many organisms, but not to a high extent infish flesh. Long-term exposure colours the fish dark and they become lethargic. Also haematological effectsappear. Copper is essential for plants. When the concentration in soil increases, for example due to elevatedconcentrations in irrigation water, to 150-400 mg/kg toxicity will appear. Copper is generally non-toxic to livestock.Sulphate (SO4)Sulphates are discharged from acid mine waste and many other industrial processes such as tanneries, textilemills and processes using sulphuric acid, sulphates or sulphides. Atmospheric sulphur dioxide discharges oncombustion of fossil fuels and roasting of sulphide ores can give rise to sulphuric acid in rainwater (acid-rain) andas such, this results in the return of sulphate to surface waters in the environment.The interactions of sulphate are governed by the associated cations, usually magnesium and sodium. Forexample, magnesium will induce diarrhea whereas, sodium will not.Sulphate has an adverse effect on the palatability of water below the concentration that causes acute toxic effects.Sulphate can cause diarrhea and poor productivity in young animals and animals without prior exposure. Thedegree of sulphur tolerance depends on species, age, adaptation period and the principal cations associated withthe sulphate ion. Adverse effects are more likely associated with high concentrations of magnesium and sodiumsulphate than calcium sulphate.Iron (Fe)Typically, the concentrations of dissolved iron in unpolluted surface water is 0.001 - 0.5 mg/l. The chemicalbehaviour of iron in the aquatic environment is determined by oxidation-reduction reactions, pH and the presenceof co-existing inorganic and organic complexing agents. Using chemical thermodynamic data it has been predictedthat iron (II) will predominate at low pH in the absence of oxygen; some Fe (II) hydroxyl complexes will be presentat alkaline pH. At low pH (<3) in oxygenated water, the Fe(III) iron predominates; however, at neutral and alkalinepH, hydroxide complexes are formed.In the presence of oxygen Fe(II) iron is oxidized and as a result, iron is usually found in the aquatic environmentas colloidal suspension of Fe(III) hydroxide particles.Iron is an essential constituent of animal diets, but can be harmful in large amounts even though it has a low orderof toxicity. Iron may cause clogging of lines to stock watering equipment.Concentrations of up to 10 mg/l have not affected palatability of water to cattle.Plants require iron for growth. Iron deficiency can occur in alkaline soils. Dissolved iron in irrigation waterprecipitates upon aeration; hence it is unavailable to the roots of plants. The precipitate can cause damage to p-lants by coating the leaves, and may clog irrigation equipment. Precipitated iron in soils binds the essentialelements phosphorous and molybdenum, making them unavailable to plants.Overhead sprinkling may result in unsightly deposits on plants, equipment and buildings.Lead (Pb)Lead is used in the production of lead acid storage batteries, tetraethyl lead, pigments and chemicals, solder,other alloys and cables. In tap water lead is dissolved from plumbing fittings containing lead in pipes, solder orservice connections to homes. Other sources of lead in the aquatic environment include soil and atmosphericfallout. Lead is a bio-accumulative general poison. A maximum of 0.5 mg/l is said to be safe for animals but casesof livestock poisoning have been reported at lower concentrations. Decomposition of organic matter by bacteria isinhibited by more than 0.1mg/l. Lead causes a film of mucous to form on gills and then over the fish’s body, thussuffocating the fish. The toxicity of lead is reduced by water hardness. Lower aquatic life appears more tolerantthan fish to lead. 92
  • 114. Mercury (Hg)Mercury (Hg) is among the most toxic of the heavy metals. In inorganic form the acute toxicity is about 0.005 to 0.1 mg/1. In nature inorganic mercury ions are easily transformed by microbial activity into organic mercurialcompounds, as methyl mercury and di-methyl mercury. Since these forms are lipophilic they are even more toxicto biota. The norm used in this guideline is based on toxicological effects on human consumption of fish.Mercury affects the central nervous system. In pregnant women methyl mercury is also transferred to the foetusand may affect the brain, which is sensitive at this stage.The concentration of mercury in fish should be less than 0.5 mg/kg fresh weight. 93
  • 115. Appendix XVIDATA SHEETS FOR QUALITY CONTROL ANALYSIS (Kafue Lagoon Area)Samples from Nitrogen Chemicals of Zambia (units in mg/l) Sampling date 11/8/04 Parameter Iron Sodium Lead Copper Cadmium Mercury ZincSample IDKN 0.25 109.0 <0.01 <0.003 <0.002 <0.0002 0.066KP (duplicate) 0.63 109.4 <0.01 <0.003 <0.002 <0.0002 0.073Percentage error 86 0 0 0 0 0 10 Sampling date 11/8/04 T. Parameter Magnesium Calcium Phosphate Ammonia TSSSample IDKM 15.84 29.6 30.8 0.19 2KO (duplicate) 16.32 33.6 42.3 0.2 6Percentage error 3 13 31 5 100 Sampling date 18/8/2004 Parameter Iron Sodium Lead Copper Cadmium Mercury ZincSample IDNK1 <0.01 124.2 <0.01 <0.003 <0.002 <0.0002 0.061NK2 (duplicate) <0.01 123.9 <0.01 <0.003 <0.002 <0.0002 0.05Percentage error 0 0 0 0 0 0 -20Samples from Lee Yeast Factory (units in mg/l) Sampling date 11/8/04 Parameter Iron Bi-carbonate Sulphate Nitrate Ammonia TSSSample IDLY 1.48 328.0 30.8 1120 0.96 261IILY (duplicate) 1.24 330 42.3 1250 0.97 222Percentage error -18 1 31 11 1 -16 Sampling date 18/8/2004 T. Parameter Magnesium Calcium Phosphate Ammonia TSSSample IDLY1 220.8 7818.6 46.5 2.70 190LY2 (duplicate) 228 7807.1 78.8 2.67 250Percentage error(%) 3 0 52 -1 27Duplicate Samples from Shikoswe Stream (units in mg/l) Sampling date 11/8/04 Parameter Iron Bi-carbonate Sulphate Nitrate Ammonia TSSSample IDS1 <0.01 192.0 27.8 0.68 2.96 32S4 (duplicate) <0.01 214 26.6 0.70 3.21 58Percentage error 0 11 -4 3 8 58 Sampling date 18/8/2004 T. Parameter Magnesium Calcium Phosphate Ammonia TSSSample IDS1 30.2 29.6 15.9 4.13 74S2 (duplicate) 28.8 29.6 15.3 5.63 38Percentage error -5 0 -4 31 -64 94
  • 116. Appendix XVII DATA SHEETS FOR QUALITY CONTROL ANALYSIS (Ngwerere River Area) Sampling 4/8/0 date 4 Parameter Mg Ca T-N2 T-PO4 NH4-N BOD COD TSS HCO3- NO3-N pH E.coli F.C F.SSample ID Garden/Ro ma Township N1 29.2 36 4.18 2.18 3.98 17 54 35 308 0.01 7.5 480 18,000 7,000 N4 31.6 36 4.14 2.1 3.68 32 67 65 320 0.01 8.2 520 18,000 9,000(duplicate)Percentageerror 8 0 -1 -4 -8 61 21 60 4 0 9 8 0 25 Ngwerere Estate Weir N2 14.6 79.2 4.61 0.6 3.37 27 35 32 316 0.01 7.8 386 6,700 2,000 N8 34.5 44 4.16 2.11 3.58 32 35 14 320 0.01 7.7 240 9,000 770(duplicate)Percentageerror 81 -57 -10 111 6 17 0 -78 1 0 -1 -47 29 -89 Kasisi Mission Dam Diversion N3 55.9 28 0.51 2.14 0.04 32 51 10 284 0.01 8.2 50 1,500 80 N6 48.1 35.2 3.61 2.16 0.01 25 92 36 290 0.01 8 60 600 120(duplicate) 4Percentageerror -15 23 150 1 -120 -25 57 113 2 0 -2 18 -86 40Legend: T-N2 = total nitrogen, T-PO4= total phosphate, NH4-N= ammonium, NO3-N= nitrate, F.C= faecal coliforms, F.S= faecal streptococci Sampling 5/8/0 date: 4 Parameter Mg Ca T-N2 T-PO4 NH4-N BOD COD TSS HCO3- NO3-N pH E.coli F.C F.SSample Id Garden/Ro ma Township N1 16.8 56 4.05 2.33 3.18 16 45 38 280 0.01 7.3 490 17,000 8,000 N7 31.6 36 4.1 2.61 3.18 16 30 35 342 0.01 7.2 550 18,000 9,000(duplicate)Percentageerror 61 -43 1 11 0 0 -40 -8 20 0 -1 12 6 12 Ngwerere Estate Weir N2 21.8 56 3.96 2.2 3.16 25 64 6 332 0.01 7.3 320 11,000 5,000 N5 34 40 3.99 2.36 3.16 14 26 10 342 0.01 6.9 620 19,000 10,000(duplicate)Percentageerror 44 -33 1 7 0 -56 -84 50 3 0 -6 64 53 67 Kasisi Mission Dam Diversion N3 41.3 12 0.29 2.18 0.18 22 35 10 228 0.01 8 260 10,000 3,000 N1 54.9 12.8 0.29 2.11 0.18 18 54 20 206 0.01 8.1 90 8,000 610(duplicate)Percentageerror 28 6 0 -3 0 -20 43 67 -10 0 1 -97 -22 -132Legend: T-N2 = total nitrogen, T-PO4= total, phosphate phosphate, NH4-N= ammonium, NO3-N= nitrate, F.C= faecal coliforms, F.S= faecal streptococci 95
  • 117. Appendix XVIIITWO-TAILED T-TEST FOR NGWERERE DATA Conductivity N1 and N2 N1 and N3 N1 N2 N1 N3 Mean 590 569.2 Mean 590 417.2 Variance 311 68.7 Variance 311 163.7 Observations 5 5 Observations 5 5 Hypothesized Mean Hypothesized Mean Difference 0 Difference 0 df 4 df 4 t Stat 2.48892 t Stat 20.79665 P(T<=t) two-tail 0.06756 P(T<=t) two-tail 3.16E-05 t Critical two-tail 2.77645 t Critical two-tail 2.77645 Magnesium N1 and N2 N1 and N3 N1 N2 N1 N3 Mean 33.58571 32.87 Mean 33.59 45.18 Variance 94.87796 80.95 Variance 94.88 163.61 Observations 7 7 Observations 7 7 Hypothesized Mean Hypothesized Mean Difference 0 Difference 0 df 6 df 6 t Stat 0.12718 t Stat -3.01699 P(T<=t) two-tail 0.90296 P(T<=t) two-tail 0.02349 t Critical two-tail 2.44691 t Critical two-tail 2.44691 Faecal coliforms N1and N2 N1and N3 N1 N2 N1 N3 Mean 10414 6293 Mean 10414 2081 3469142 3469142 947934 Variance 9 2E+07 Variance 9 8 Observations 7 7 Observations 7 7 Hypothesized Mean Hypothesized Mean Difference 0 Difference 0 df 6 df 6 t Stat 2.18385 t Stat 4.27283 P(T<=t) two-tail 0.07168 P(T<=t) two-tail 0.00525 t Critical two-tail 2.44691 t Critical two-tail 2.44691The Null Hypothesis (NH) was used to assume no significant difference between the means forsampling points N1 and N2 and N1 and N3. The NH was accepted for conductivity, magnesium andfaecal coliforms for N1 and N2 but rejected for N1 and N3 because in the former case the calculated t-value (t Stat) was less than the critical value (t Critical) and in the latter it was vice-versa. Therefore, itcan be inferred with 95% confidence that there was no significant difference in water quality (withrespect to the tested parameters) between sampling points N1 and N2, and that there was significantdifference between N1 and N3. Only three (3) parameters were chosen out of twenty-six (26) toillustrate how the t-Test was used to arrive at some conclusions during data analysis. The trend was thesame for most of them. 96
  • 118. Appendix XVRAPPORTEUR’S REPORT DISSEMINATION STUDY WORKSHOP ON THE ‘‘USE OF WASTEWATER FOR IRRIGATION IN VEGETABLE GROWING IN THE KAFUE LAGOON AREAS AND ALONG NGWERERE RIVER’’ HELD AT PAMODZI HOTEL, LUSAKA 2ND NOVEMBER 2004 BY Lemmy N. Namayanga1.0 IntroductionThe Zambia Social Investment Fund (Zamsif) of the Ministry of Finance and National Planning (MoFNP)under the auspices of the Poverty Monitoring and Analysis (PMA) funded both the above-mentionedstudy and the dissemination workshop. The study entitled ‘Effects of using wastewater on vegetablegrowing and the associated socio-economic impacts on farmers in the Kafue Lagoon and alongNgwerere River’ was conducted over a four months spell. As per tradition, the results and findings ofsuch studies are usually disseminated through workshops were members of the public and keystakeholders are accorded an opportunity to criticise the findings and thus strengthening the studybefore a final report is passed.In line with the above, the findings of this study conducted by Messrs Charles Chisanga and OscarSilembo was disseminated at a workshop held at the Pamodzi Hotel-Lusaka on the 2nd of November2004.This report presents the proceedings of the workshop and the recommendations agreed by the meeting.2.0 OpeningThe Chairman of the day started by apologising to the participants for the delay in commencing theproceedings of the workshop by 40 minutes. The delay was due to poor attendance, which compelledthe organisers to reschedule the starting time in order to allow more time for stakeholders to come. Thiswas followed by self-introductions of participants. The chairman then called upon the Zamsif Study FundAdviser Dr. Henry Sichingabula to put forward his welcoming remarks before calling upon the workshopofficiatee.The Study Fund Advisor expressed happiness on behalf of PMA that the study had come to itscompletion but disappointment on the turnout of the invited key stakeholders. He nonetheless, urged theparticipants to diligently participate and freely contribute to the deliberations that will enrich thesubstance of the research study. He assured the present participants that each one of them would get acopy of the study report when its finally done and that all the local libraries, Local Authorities and eventhe absent key stakeholders.The dissemination workshop was officially opened by the Director of the Environmental Council ofZambia who delivered an analytical and encouraging opening speech. See Annex I for the details of thespeech. The meeting was declared officially opened at 09:40 hrs.2.1 Study PresentationThe Principal Researcher, Mr. C. Chisanga presented the whole study paper in the following sequence. • Introduction and background to the study • Methodology, data collection and analysis 97
  • 119. • Study Analysis and results • Conclusions and recommendations2.2 Reviewers CritiquesTwo research study reviewers were present and each of them had to present their observations withrespect to the work done or not done under the study, the presentation of the findings and results. Thetwo reviewer’s critiques were from: Ms. Mwiche Kabwe, an Environmental Planning Specialist from theEnvironmental Council of Zambia (ECZ) and Mr. Kavyanga Yambayamba, a Lecturer in the School ofAgriculture at the University of Zambia (UNZA). Their main critique points were as recorded below.2.2.1 Ms Mwiche KabweShe begun by commending the researchers on the work done and for attempting to address all theobjectives the researchers had set for themselves. However, the following were the points she raisedthat the researchers must endeavour to redress: • Although the objectives were somewhat achieved, she felt that the study should have balanced the analysis of the socio-economic status of the vegetable farmers (income and expenditure) particularly addressing issues of medical expenses, school fees and transport costs. • Bearing in mind that the length of study was limiting, she however pointed out that the researchers ought to have done some more work in assessing the quality of effluent and human health records by obtaining information from secondary sources. • She also observed that the recommendations put forward by the researchers were more skewed towards addressing policy issues rather than suggesting measures of reducing health hazards associated with the practice and use of wastewater in vegetable growing. • The researchers did not comprehensively address the issue of environmental value of wastewater as perceived by the communities where the study was conducted. • She further observed and suggested that the public health analysis would be more complete if data in the Ngwerere River study area could consider information and data from the Chipata Health Centre other than concentrating on the Kasisi data only.2.2.2 Mr. Kavyanga YambayambaMr. Yambayamba begun by acknowledging the importance of the study and its role in attempting toexplore and support ways of fighting poverty. He however raised the following observations: • That the researchers needed to add more information under the study area description section to include such data and information on population sizes of the two study areas, general economic status and type and quality of effluent in each study area. • The study report ought to explain the methodology of the study clearly explaining points such as why there were 30 respondents at Kafue Lagoon and 50 from the Ngwerere River study area. He further elucidated that methodology had a direct bearing on the results of any study hence the care it deserves. • He also urged the researchers to explain the differences in gender engagement in vegetable growing in the two study areas. 98
  • 120. • Key to every study is the inclusion of a control study theme, which he noticed as a major gap in this study. He nonetheless suggested that this shortfall could be recorded as a limitation in the study’s report. • Having presented findings on land tenure systems in the two study areas, the researchers should have provided an explanation on the implications of such systems on vegetable growing. • Also to be included in the study report will be an insight into the yields of the vegetables in the study areas, an explanation that is missing. • Finally he observed that there was no direct evidence adduced in the report linking the study to public health issues. Here only indications are required.2.3 Plenary DiscussionUnder the plenary discussion, a lot of issues were raised and discussed of which the most importantones are as recorded below: 1. It was agreed that time was a significant limiting factor in this study hence the non- exhaustive address of issues. 2. The indication of the population in one’s study area was very important as it gave an idea as to how large one’s sample population ought to be. 3. The above point also raised the question of whether the researchers had actually pre- tested their questionnaire before administering it to their respective study areas, an activity which was not done. 4. Participants discussed a recommendation that purported the lack of a policy on the use of wastewater in the country to which the meeting was informed that the technology of wastewater usage was relatively new to this part of the world although the practice is wide spread on the Copperbelt and Lusaka Provinces. The workshop further learnt that even the irrigation policy that is about to be tabled before Cabinet was silent on the use of wastewater for agriculture let alone any other use. 5. Thus, it was suggested that the immediate above point be brought forth as a recommendation, which could be tailored in such a way as to contribute to poverty reduction after further research. 6. Companies that discharge effluent were implored to have a sense of social responsibility by cleaning their effluent before discharging it into the aquatic environment. To this point the meeting was informed of the role of ECZ and the need strengthened enforcement and investment in wastewater treatment facilities. 7. Debate ensued on the incomes reported in the study as being too low, to which the meeting heard that the vegetable farmers were poor at adding value to other benefits and that income does not reflect the actual value of the benefits. 8. It was also discussed that there was need to deliberately consider comparison of environmental and bio human data monitoring information in order to satisfactorily appreciate the impact of vegetable growing on public health. 99
  • 121. 9. Finally, the choice and use of words was also raised. Words that were discussed include: the word ‘wastewater’ in the title as to what it really means and no-employed/self employed with respect to the respondents.2.4 Workshop RecommendationsThe workshop came up with four (4) main recommendations that are reproduced below: • Policy markers should recognise the use of wastewater in agriculture and its potential contribution to poverty reduction but only after extensive research. • Government should come up with a deliberate effort to invest in rehabilitation or construction of wastewater treatment plants with respect to sound technology that take into account the possible reuse of waste water in agriculture. • Concerned Government Departments and other key stakeholders should embark on a sensitisation campaign on effects, impacts and best practices on the use of wastewater. • Need to sensitise politicians on the need to adhere to professional guidelines and expert advise on land-use planning.2.5 Rapporteur’s RemarksThis report represents the rappoteur’s remarks.3.0 Vote of ThanksA Mr. Sikazwe, from an NGO delivered the vote of thanks to the researchers, financiers and participantsfor their contributions4.0 Closing RemarksThe official closing remarks were delivered by Mr. Emmanuel Sibanda, the PMA Manager at 12:57hours. He mentioned that the study that was being presented in this dissemination workshop was onlynumber 14 with 37 more studies to go. He thanked everyone for having contributed to the strengtheningof the study. He also thanked ECZ for making the study strong and the Director of ECZ for havingaccepted to officiate at very short notice. Finally Mr. Sibanda urged the researchers to carefully searchthrough the recommendations given and chart a way forward to strengthening the study substance andreport.The workshop was declared closed at 13:05 hours. 100
  • 122. Annex II Workshop ProgrammeDate Time Activity2-11-2004 08:15 Registration of participants 09:00 Welcoming remarks – Chairman 09:10 Introduction of participants 09:20 Welcome remarks: PMA Representatives 09:25 Official opening by Guest of Honour (Mr. Edward Zulu) 09:30 Introduction and background to the study 10:00 Methodology, data collection and analysis 10:30 Tea/Coffee Break 10:45 Study Analysis and Results 11:20 Conclusions and recommendations 11:40 Reviewer’s critique 11:55 Plenary Discussion 12:30 Meeting Recommendations 12:45 Rapporteur’s Remarks 12:50 Vote of thanks 12:55 Closing Remarks 13:00 Lunch 14:00 Departure 101
  • 123. Annex II: Opening SpeechOPENING SPEECH BY THE GUEST OF HONOUR AT THE OFFICIAL OPENING OF THEDISSEMINATION WORKSHOP AT PAMODZI HOTEL ON USE OF WASTEWATER FORIRRIGATION IN VEGETABLE GROWING IN THE KAFUE LAGOON AREAS AND ALONGNGWERERE RIVER HELD AT PAMODZI HOTEL, LUSAKA ON 2ND NOVEMBER 2004THE CHAIMAN, DIRECTORS OF GOVERNMENT MINISTRIESMINISTRY OF ENERGY AND WATER DEVELOPMENTMINISTRYF OF AGRICULTURE AND COOPERATIVESENVIRONMENTAL COUNCIL OF ZAMBIA, NGOS AND COOPERATING PARTNERS SUCH ASDANIDA AND WATERAID ZAMBIATHE POVERTY MONITORING ANALYSIS (PMA) REPRESENTATIVESMAY I SIMPLY SAY DISTINGUISHED LADIES AND GENTLEMENIT IS INDEED MY HONOUR AND PRIVILEGE TO BE INVITED TO OFFICIATE AT THISDISSEMINATION WORKSHOP ON THE STUDY ENTITLED ‘‘EFFECTS OF USING WASTEWATERON VEGETABLE GROWING AND THE ASSOCIATED SOCIO-ECONOMIC IMPACTS ON FARMERSIN THE KAFUE LAGOON AREAS AND ALONG NGWERERE RIVER’ WHICH WAS UNDERTAKENUNDER THE POVERTY MONITORING ANALYSIS OF ZAMBIA SOCIAL INVESTMENT FUND. I AMINFORMED THAT THE RESEARCHERS OF THIS SMALL STUDY ARE ALL MEMBERS OF THEWATER AND SANITATION ASSOCIATION OF ZAMBIA (WASAZA) FOR THE WATER ANDSANITATION ASSOCIATION OF ZAMBIA (WASAZA). INDEED I FEEL HONOURED BECAUSE THISWORKSHOP COULD NOT HAVE COME AT A BETTER DATE THAN WHEN COMMUNITIESELSEWHERE ARE REUSING WASTEWATER TO GROW HIGH VALUE CROPS WHICH ENHANCETHEIR INCOME AND LIVELIHOOD.I AM INFORMED THAT THE REUSE OF WASTEWATER FOR AGRICULTURE IS “THE CHALLENGEOF WATER RESOURCES MANAGEMENT IN THE 21ST CENTURY”. IN VIEW OF THEPREDICATION BY THE UNITED NATIONS THAT THE WARS OF THE 21ST CENTURY WILL BE ONWATER. I CANNOT AGREE WITH YOU MORE, SEEING THAT WE AS ZAMBIANS SHOULDADDRESS THE CHALLENGES FACING OUR COUNTRY IN THE DEVELOPMENT ANDMANAGEMENT OF THE WATER RESOURCES FOR IRRIGATION AND INDEED OTHER USES INTHIS CENTURY. WITH OUR PERCULIAR SOCIAL, POLITICAL, ECONOMIC AND ENVIRONMENTALCONDITIONS WE SHALL DRAW ON THE KNOWLEDGE OF OUR COLLEAGUES FROM THE SMALLSTUDY ON HOW WE CAN ADDRESS THE ISSUES OF REUSING WASTEWATER FORAGRICULTURE. YOU WILL AGREE WITH ME THAT THOUGH ZAMBIA IS ENDOWED WITHABUNDANT WATER RESOURCES, THE POPULATION INCREASE AND THE DEMANDS FROMAROUND THE COUNTRY AND THE REGION ON THE WATER RESOURCES ARE ENORMOUS.THE ZAMBIAN NATIONAL WATER POLICY OF 1994 SPECIFIES THAT WATER FOR IRRIGATIONSHOULD BE FIT FOR HUMAN CONSUMPTION AND NOT CAUSE SOIL DEGRADATION BUTENHANCE HIGH CROP YIELD. WITHIN THE BROAD OBJECTIVE FOR AGRICULTURE, THE PRSPPAPER INDICATES THAT SINCE THE POOR RELY OFTEN ON THE ENVIRONMENT FOR THEIRLIVELIHOOD, ATTACKING POVERTY IN RURAL AND PERI-URBAN AREAS IS NECESSARY INIMPROVING PEOPLE’S ABILITY TO DERIVE LIVELIHOOD FROM NATURAL RESOURCES. ON THEOTHER HAND, THE ZAMBIAN HEALTH POLICY EMPHASISES THAT IN ORDER TO HAVE A WELL-NOURISHED AND HEALTH POPULATION THAT CAN CONTRIBUTE TO THE NATIONAL 102
  • 124. ECONOMIC DEVELOPMENT THERE IS NEED TO ACHIEVE SUSTAINABLE FOOD AND NUTRITIONSECURITY.THESE CHALLENGES OF ALLEVIATING POVERTY CANNOT BE ADDRESSED BY THEGOVERNMENT ALONE. WE THEREFORE NEED TO HOLD HANDS AS PUBLIC, PRIVATE SECTOR,NGOs AND ALL COOPERATING PARTNERS IN THE WATER AND SANITATION SECTOR TOADDRESS THE CHALLENGES AHEAD OF US. IT IS FOR THIS REASON THAT ZAMSIF THROUGHTHE MINISTRY OF FINANCE AND NATIONAL PANNING ALLOCATED MONEY TO THE PMA FORSMALL STUDIES WITH FOCUS ON POVERTY ALLEVIATION.MR CHAIRMAN, KNOWLEDGE IS POWER. WE ARE HERE TO SHARE KNOWLEDGE. THE WORLDTODAY WITH THE INFORMATION TECHNOLOGY ADVANCES HAS BECOME A GLOBAL VILLAGEIN WHICH YOU CAN SHARE INFORMATION AT THE TOUCH OF A BUTTON. LOCALLY WE HAVENOT DONE TOO WELL TO SHARE THE MANY GOOD PRACTICES THAT HAVE BEENDEVELOPED OVER THE YEARS. WE HAVE FOR TOO LONG OPERATED AS INDIVIDUALORGANISATIONS WITH THE VERY NARROW BRIDGE BETWEEN THE INITIATIVES OFGOVERNMENT AND THE PRIVATE SECTOR. IT IS MY SINCERE HOPE THAT COLLABORATIVERESEARCH THROUGH ASSOCIATIONS SUCH AS WASAZA WILL BE THE BRIDGE THROUGHWHICH WE WILL PUT OUR HEADS TOGETHER TO SHARE THESE CHALLENGES AND FORGEAHEAD AS A UNITED FRONT FOR THE BENEFIT OF ALL WATER USERS AND THE GOOD OFOUR ENVIRONMENT.THE ISSUES OF WATER RESOURCES DEVELOPMENT AND MANAGEMENT ARE CROSSCUTTING AND NO SINGLE INDIVIDUAL OR INSTITUTION CAN CLAIM TO KNOW IT ALL, MR.CHAIRMAN, WE JUST HAVE TO COME TOGETHER AND DIALOGUE ON POLICY ISSUES ASRAISED IN THE SMALL STUDY ON REUSE OF WASTEWATER AND ITS INPLICATIONS ANDBEGIN NETWORKING WITH EVERYONE.THE GOVERNMENT OF THE REPUBLIC OF ZAMBIA HAS PUT IN PLACE A POLICY AND LEGALFRAMEWORK IN WHICH TO OPERATE AND FOR ALL THE ACTORS TO BE EFFECTIVE IN THEEXECUTION OF THEIR RESPONSIBILITY AND IT IS OPEN TO ANY SUGGESTIONS ON THEREFINEMENT OF THESE ARTICLES FOR THE BETTERMENT OF THE WATER SECTOR. FORTHIS REASON VARIOUS OPPORTUNITIES HAVE BEEN PROVIDEDTHROUGH WORKSHOPS ANDCONSULTATIVE MEETINGS.IN CONCLUSION I WISH TO URGE YOU TO BE REALISTIC IN YOUR RECOMMENDATIONS ANDCOME UP WITH ACHIEVABLE SOLUTIONS WITHIN THE CONTEXT OF REUSING WASTEWATERAS AN ALTERNATIVE SOURCE OF IRRIGATION WATER AND NUTRIENTS FOR CROPPRODUCTION. YOU SHOULD NOT ONLY LOOK AT THE NEGATIVE IMPACTS OF REUSINGWASTEWATER ENVIRONMENT AND HEALTH OF COMMUNITIES BUT BE MINDFUL OF THEPEOPLE IN THE RURAL AND PERI-URBAN AREAS WHERE THIS ACTIVITY IS TAKING PLACE.IT IS NOW MY HONOUR AND PRIVILEGE TO DECLARE THIS DISSEMINATION WORKSHOPOFFICIALLY OPEN.THANK YOU. 103
  • 125. Annex III List of Workshop Participants NAMES ORGANISATION TELEPHONE E-MAIL1 Ms Mainess Maninga Chainama College 097 715318 Lifegate Disaster2 K. M Kowa Relief MGT Program 095 817920 mwakapa@yahoo.com Lifegate Disaster3 A. L. Sikazwe Relief MGT Program 095 764214 lifegatedrmp@yahoo.com4 A. Sichlombe Lusaka WSC 095 792758 asichilombe@yahoo.com5 O. Katooka Lusaka WSC 095 790655 okatooka@lwsc.com.zm6 M. Kabwe ECZ 254023/59 mkabwe@necz.org.zm Box 50291, Lusaka:7 Mwase Phiri MACO/TSB tel: 255346 mwasephiri@yahoo.com Box 50062, Lusaka;8 Getrude Bwalya Zamsif tel: 096769383 getrudebwalya@yahoo.com9 Lemmy Namayanga ECZ 096 92535410 E. H. Zulu ECZ ezulu@necz.org.zm11 Evelyn M./ Mbulo Zamsif Box 31559, Lusaka evelyn@zamsif.org.zm12 H. N. Sichingabula Zamsif Box 31559, Lusaka13 Astridah Lombe WASAZA Box 31980, Lusaka Dr. Kavwanga14 Yambayamba UNZA Box 32379, Lusaka15 Mr. Silanda MFNP-PMA Lifegate Disaster16 Ms Wamulume Relief MGT Program Mr. Charles17 Chisanga WASAZA Box 33493, Lusaka chisanga@lycos.com18 Edward Zulu ECZ 254023/5919 Mr. Oscar Silembo WASAZA/DWA sils4@yahoo.com 104