Background1. Rural India has more than 700 million people residing in about 1.42 million habitations spread over 15 diverse ecological regions.2. 85 % of rural population in India is solely depended on ground water, which is depleting at a fast rate.3. India has 16% of the world’s population and 4% of its fresh water resources.4. Ninety 2% groundwater extracted is used in the agricultural sector, five and 3 % respectively for industrial and domestic sector.
Water Quality Problems1. Excessive extraction of ground water make water critical critical during summer months in many parts of the country.2. 70 million people in 20 states are at risk due to excess fluoride and around 10 million people are at risk due to excess arsenic in ground water.3. Ingress of seawater into coastal aquifers as a result of over- extraction of ground water has made water supplies more saline, unsuitable for drinking and irrigation.4. It is estimated that around 37.7 million Indians are affected by waterborne diseases annually, 1.5 million children are estimated to die of diarrhoea alone and 73 million working days are lost due to waterborne disease each year.
Water Pollution Polluting Agents* (Public Health Services)
Water Quality Surveillance Critical Parameters to be tested for assessing water qualityAlkalinity* –Sources – i) salts of weak acids (CO3-2, HCO3-, OH-….) ii) *Algae consuming CO2 *Impact – i) Induces bitter taste, unpalatable ii)Foul pipes and water system appurtenances Acceptable Limit Limit for Rejection Result 200 mg/L 600 mg/L 512 mg/L
Hardness – defined as concentration of multi-valent metallic cation in solnSources – i) dissolved Ca++ & Mg++ and their salts ii) Other ions Fe++, Mn++, Al+3 (in small quantities) iii) Area where top-soil is thick & lime stone formation arepresentImpact – i) Consumes soap* ii) Scale formation in boilers and pipes* Acceptable Limit Limit for Rejection Result 75 mg/L 110 mg/L 20 mg/L
Arsenic –Sources – i) Natural source: volcanic ash, weathering of arsenic containing minerals and ores ii) Artificial source: Smelter emission*, Mining waste Wood preservatives such as Chromated copper arsenate Arsenic bearing fertilizers, Deposition from coal combustionImpact – i) Hinders aquatic life ii) Increases risk of cancer* and other various acute diseases*Cases- High Arsenic contamination in Ground water in West Bengal* and Bangladesh* Acceptable Limit Limit for Rejection 0.05 mg/L 0.05 mg/L
Instrument used Absorption vs. Concentration Spectrophotometer graph
Chloride –Sources – i) Nonpoint source: a) Natural* b) Agriculture* c) Residential and Urban* ii) Point source *Reagent Used for test- Indicator: K2CrO4; Titrant: N/70 AgNO3 solnImpact – i) >250 mg/L the taste is salty ii) Evapotransportation increase salinity makes crops difficult to absorb water *Application- Used as a tracer* Acceptable Limit Limit for Rejection Result 200 mg/L 600 mg/L 36 mg/L
Total Coliform –Sources – i) Contamination of animal feces in soil & ground water ii) Agricultural runoff iii) Effluent from septic systems or sewage dischargesReagent Used for test- Beef Extract, Lactose & PeptoneImpact – Most coliform bacteria do not cause illness however…* i) Positive fecal coliform results fecal pollution ii) Stomach and intestinal illness* iii) Waterborne pathogenic* Acceptable Limit Limit for Rejection Result 0 1 coliform colony 460 per 100 ml (in waster water) per 100 ml 0 per 100 ml (in tap water)
Instrument Used Autoclave- for sterilizing Incubator- for incubation broth for 3hrs of organism at 35oC
pH–Cause of pH change– i) Depletion of CO2 in water increases pH ii) High pH in lake during summer * iii) Increases due to increase of carbon-based mineral molecules suspended in the solution iv) Is decreased by Acid rainImpact – i) corrosive effects of acidity ii) high or low pH harm fish by denaturing cellular membranes. iii) as the pH approaches 5, non-desirable species of plankton and mosses may begin to invade at bottom iv) aesthetic problems dur to low pH* & high pH
Acceptable Limit Limit for Rejection Result 7-8.5 6.5-9.2 7.63 Instrument Used– pH meter
Fluoride –Reagent Used for test- SPANDS solution, Zirconyl-acid reagent, reference solution, sodium ardenate solutionHealth Impact – i) Immediate symptoms include digestive disorders, skin diseases, dental fluorosis. ii) Fluoride in larger quantities (20-80 mg/day) taken over a period of 10-20 years results in crippling and skeletal fluorosis which is severe bone damage.Affected states – Andhra Pradesh, Assam, Bihar, Chattisgarh, Gujarat, Haryana, Jharkhand, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Orissa, Punjab, Rajasthan, Tamil Nadu, Tripura, Uttar Pradesh, West BengalInstrument Used– Spectrophotometer
Iron –Reagent Used for test- Conc HCl, Hydroxylamine solution, Ammoniun acaetate, sod. acetate soln, phenanthroline soln, stock iron solnHealth Impact – i) A dose of 1500 mg/l has a poisoning effect on a child as it can damage blood tissues. ii) Digestive disorders, skin diseases and dental problems.Affected states – Arunachal Pradesh, Assam,Bihar, Chattisgarh, Jharkhand, Jammu and Kashmir, Karnataka, Kerala, Manipur, Meghalaya, Mizoram, Madhya Pradesh, Maharashtra, Nagaland, Orissa, Punjab, Rajasthan, Sikkim, Tripura, Tamil Nadu, Uttar Pradesh, West Bengal, A&N Islands, Pondicherry Acceptable Limit for Result Limit Rejection 0.3 mg/L 1 mg/L 0.3 mg/L
Turbidity –Sources – presence of iron, chlorine, suspended particles.Instrument used for test- NephelometerImpact- 1. Aesthetic value 2. High turbidity may be an indication of Iron and other impuritiesInstrument Used– Nephlometer