This document provides guidelines for the design and construction of water and wastewater systems in Trinidad and Tobago. It outlines the administrative approval process, which involves obtaining outline approval, final approval, and a completion certificate. It provides design guidelines for water pipelines and related infrastructure, including estimating water demand, allowable pipeline velocities, head losses, and material specifications. Guidelines are also provided for wastewater sewers, pumping stations, and on-site wastewater disposal systems. The document aims to assist practitioners in meeting statutory requirements for water and wastewater facilities in a safe and efficient manner.
WASA Wastewater and Potable Water Design RequirementsJeffrey James
This document provides a summary of revisions made to the Water and Sewerage Authority (WASA) of Trinidad and Tobago Water and Wastewater Design Guideline Manual. Key changes include: adding minimum flood level requirements; changing the minimum fire duration criteria; revising PVC pipe specifications; adding a new section on polyurethane coating; revising fence height requirements; adding new sections on impoundment reservoirs and trenchless technologies; and adding criteria for as-built drawings and standards. The document contains a table of contents outlining the various sections and topics covered in the design guideline manual.
Wasa guidelines for design and construction -boett-2003Jeffrey James
This document provides guidelines for the design and construction of water and wastewater systems in Trinidad and Tobago. It discusses the scope, submission requirements, and design factors for water pipelines, storage tanks, pump stations, and related infrastructure. Key points covered include estimating water demand, allowable pipeline velocities and head losses, placement of valves, air release valves, and other appurtenances. Material specifications and construction standards are also outlined to ensure system quality and reliability.
Wasa new services plumbing inspectorate processJeffrey James
The document outlines the plumbing inspectorate process for licensed sanitary constructors in Trinidad and Tobago. It involves several key steps: 1) Application submission with required documents; 2) Design review and approval or defect identification by inspectors; 3) Roughin and final inspections to check conformity with codes; 4) Testing of plumbing systems; 5) Obtaining a completion certificate once inspections are passed. Re-inspection fees apply if initial inspections or tests fail to meet code standards.
Sanitary engineering-1-Water treatment and water supply Ahmed Salem Seaf
This document provides an overview of water supply engineering and sanitary engineering. It discusses environmental engineering and its focus on managing natural resources and protecting the environment. Sanitary engineering is defined as supplying communities with potable water and treating wastewater. The document then covers various water sources, their characteristics, water treatment processes, and the components and design of water intake and collection works.
The document outlines procedures for determining various types of solids in water samples, including total solids, fixed solids, volatile solids, total dissolved solids, suspended solids, and settleable solids. Total solids include all materials retained after evaporation and drying of a sample. Fixed solids are the residues remaining after ignition, while volatile solids are lost during ignition. The procedures involve filtering samples, evaporating filtrates to determine dissolved fractions, and weighing residues to calculate concentrations.
This document discusses the design of open channels. It describes the process of designing channels to prevent silting and scouring. The key steps are determining the depth, bed width, side slopes, and longitudinal slope of the channel based on the discharge and sediment load. It also discusses different channel types and design methods for rigid and erodible channels. The main design methods covered are the permissible velocity method and tractive force method for erodible channels. Design procedures and examples are provided for rectangular and trapezoidal channel sections.
This document provides a list of 50 potential water resource engineering projects for BE/BTech and ME/MTech students. The projects cover a wide range of topics related to water such as groundwater potential and quality studies, water treatment plant design, rainwater harvesting, river training works, and interlinking of rivers. Contact information is provided for Sree Samarth Project Solution in Aurangabad for students interested in pursuing one of the projects.
This document discusses water demand forecasting for urban water supply systems. It covers key factors in determining water demands, including population projections, per capita water usage rates that vary by location and usage type, and factors that affect demand like climate, income levels, development patterns and water conservation efforts. The document provides guidance on estimating average day, maximum day and peak hour water demands that systems are designed for, as well as common methods for population forecasting.
WASA Wastewater and Potable Water Design RequirementsJeffrey James
This document provides a summary of revisions made to the Water and Sewerage Authority (WASA) of Trinidad and Tobago Water and Wastewater Design Guideline Manual. Key changes include: adding minimum flood level requirements; changing the minimum fire duration criteria; revising PVC pipe specifications; adding a new section on polyurethane coating; revising fence height requirements; adding new sections on impoundment reservoirs and trenchless technologies; and adding criteria for as-built drawings and standards. The document contains a table of contents outlining the various sections and topics covered in the design guideline manual.
Wasa guidelines for design and construction -boett-2003Jeffrey James
This document provides guidelines for the design and construction of water and wastewater systems in Trinidad and Tobago. It discusses the scope, submission requirements, and design factors for water pipelines, storage tanks, pump stations, and related infrastructure. Key points covered include estimating water demand, allowable pipeline velocities and head losses, placement of valves, air release valves, and other appurtenances. Material specifications and construction standards are also outlined to ensure system quality and reliability.
Wasa new services plumbing inspectorate processJeffrey James
The document outlines the plumbing inspectorate process for licensed sanitary constructors in Trinidad and Tobago. It involves several key steps: 1) Application submission with required documents; 2) Design review and approval or defect identification by inspectors; 3) Roughin and final inspections to check conformity with codes; 4) Testing of plumbing systems; 5) Obtaining a completion certificate once inspections are passed. Re-inspection fees apply if initial inspections or tests fail to meet code standards.
Sanitary engineering-1-Water treatment and water supply Ahmed Salem Seaf
This document provides an overview of water supply engineering and sanitary engineering. It discusses environmental engineering and its focus on managing natural resources and protecting the environment. Sanitary engineering is defined as supplying communities with potable water and treating wastewater. The document then covers various water sources, their characteristics, water treatment processes, and the components and design of water intake and collection works.
The document outlines procedures for determining various types of solids in water samples, including total solids, fixed solids, volatile solids, total dissolved solids, suspended solids, and settleable solids. Total solids include all materials retained after evaporation and drying of a sample. Fixed solids are the residues remaining after ignition, while volatile solids are lost during ignition. The procedures involve filtering samples, evaporating filtrates to determine dissolved fractions, and weighing residues to calculate concentrations.
This document discusses the design of open channels. It describes the process of designing channels to prevent silting and scouring. The key steps are determining the depth, bed width, side slopes, and longitudinal slope of the channel based on the discharge and sediment load. It also discusses different channel types and design methods for rigid and erodible channels. The main design methods covered are the permissible velocity method and tractive force method for erodible channels. Design procedures and examples are provided for rectangular and trapezoidal channel sections.
This document provides a list of 50 potential water resource engineering projects for BE/BTech and ME/MTech students. The projects cover a wide range of topics related to water such as groundwater potential and quality studies, water treatment plant design, rainwater harvesting, river training works, and interlinking of rivers. Contact information is provided for Sree Samarth Project Solution in Aurangabad for students interested in pursuing one of the projects.
This document discusses water demand forecasting for urban water supply systems. It covers key factors in determining water demands, including population projections, per capita water usage rates that vary by location and usage type, and factors that affect demand like climate, income levels, development patterns and water conservation efforts. The document provides guidance on estimating average day, maximum day and peak hour water demands that systems are designed for, as well as common methods for population forecasting.
The document discusses the use of low impact development (LID) approaches to manage stormwater and mitigate flooding issues. It provides background on LID concepts like bioretention cells, permeable pavements, green roofs, and rain gardens. It then details how the Storm Water Management Model (SWMM) software can be used to simulate the hydrologic performance of different LID controls. The document provides design parameter values for various LID types and guides the user through setting up a SWMM model with LID controls applied to subcatchments to analyze flooding impacts.
Drainage Engineering (Drainage and design of drainage systems)Latif Hyder Wadho
This document provides information on drainage and the design of drainage systems. It discusses the following key points in 3 sentences:
Land drainage and field drainage are the two main types of drainage, with field drainage focusing on removing excess water from the root zone of crops. The main goals of field drainage are to bring soil moisture below saturation to allow for optimal plant growth and to improve soil structure and hydraulic conductivity. The different methods of field drainage include horizontal drainage methods like surface drainage and sub-surface drainage, as well as vertical drainage through tube wells.
The document discusses different types of dams classified by structure and materials, including gravity dams, arch dams, embankment dams, and barrages. Embankment dams, the most common type worldwide, are simple compacted earth structures that rely on their mass to resist forces. The document also describes various embankment dam types such as rock fill dams, concrete-face rock fill dams, and earth fill dams.
internship report on performance of sewage treatment plantAshok Devasani
the report presents a clear description about the performance of 30 MLD sewage treatment plant located in the vicinity of Hyderabad. it also provides a general information of the different sewage treatment process
WEIRS VERSUS BERRAGE
TYPES OF WEIRS
COMPONENT PARTS OF A WEIR
CAUSES OF FAILURE OF WEIRS & THEIR REMEDIES
DESIGN CONSIDERATIONS
DESIGN FOR SURFACE FLOW
DESIGN OF BARRAGE OR WEIR
Design mannual for small scale irrigation scheme bookSurendra Maharjan
This document provides an overview and guidelines for designing small-scale irrigation schemes in Nepal. It was published by the Ministry of Federal Affairs and Local Development in association with HELVETAS Swiss Intercooperation Nepal. The document defines key terms related to irrigation, describes various irrigation techniques like surface, subsurface and sprinkle irrigation. It also outlines the steps involved in project identification, feasibility study, surveys and hydrological analysis. Design guidelines are provided for headworks, canals, sediment control structures, canal structures and cross drainage works. Micro irrigation techniques like pond irrigation, sprinkle irrigation and drip irrigation are also covered. The document aims to provide practical design guidance for small irrigation projects tailored to the local context in Nepal.
SEWAGE TREATMENT PLANT mini project reportNitesh Dubey
This document provides information about a research project analyzing the quality of treated sewage water from shipboard sewage treatment plants. Water samples were taken from 32 ships and analyzed for parameters like coliform bacteria, suspended solids, and biological oxygen demand. The results showed that none of the treated sewage water samples met standards in the MARPOL Annex IV regulations. The document also describes regulations for sewage discharge, potential health and environmental risks of untreated sewage, and common types of sewage treatment systems used on ships.
This document discusses various types of drainage infrastructure used for roads, including culverts, catch basins, gutters, ditches, and drop inlets. It notes that proper road drainage is important for flood control, protecting infrastructure, and environmental impacts. The document is authored by group members Matala Mayambi Tresor, Waseem Akram, and Kanonga Munyungu Arthur.
The document discusses open channel design for both rigid boundary and erodible channels. It describes the key steps in designing trapezoidal channels including determining depth, bed width, side slopes, and longitudinal slope. For rigid boundary channels, the most common design approach is to use Manning's equation to select dimensions that produce non-silting, non-scouring velocities. For erodible channels, two common methods are discussed: the permissible velocity method, which ensures the mean flow velocity is below erosion thresholds; and the tractive force method, which involves equating tractive forces to critical shear stresses of the channel material.
This document summarizes different types of tube wells based on various classification criteria. It describes tube wells as holes bored into the ground to tap groundwater from deep aquifers. Tube wells are classified based on their entry of water, construction method, depth, and type of aquifer tapped. Shallow tube wells are usually less than 60m deep while deep tube wells range from 60-300m deep. Tube wells can be screen wells, cavity wells, drilled wells, driven wells, or jetted wells depending on their construction method. They can tap water table aquifers, semi-artesian aquifers, or artesian aquifers based on the aquifer type.
This document discusses the design of irrigation channels. It covers several key points:
1) The design of irrigation channels involves selecting the channel alignment, shape, size, bottom slope, and whether lining is needed. The design determines the cross-sectional area, depth, width, side slopes, and longitudinal slope.
2) Non-alluvial channels are excavated in soils with little silt, like clay or hard loam. They are designed based on maximum permissible velocity to prevent erosion. Manning's equation or Chezy's equation are used.
3) An example problem demonstrates designing a trapezoidal channel in non-erodible material to carry a discharge of 15 cubic meters per second with a
This document is a graduate report on urban infrastructure prepared by two students for a course at the Sardar Vallabhbhai National Institute of Technology in Surat, India. It discusses various components of a water supply network including collection of water from sources, transmission to a water treatment plant, purification processes at the plant, and distribution of treated water. Diagrams illustrate the flow of water from an intake well drawing from the Tapi River through various treatment units to pumping stations.
This document provides design considerations for a sewerage system for a small township. Key assumptions are made about sewage generation rates and peak flows. Manning's formula and the rational method are used to size sewer pipes and drainage channels. Population calculations are made to determine sewage flows from different areas. Pipes with a diameter of 15cm and slope of 1:85 are designed to collect sewage from individual units. A 22.5cm pipe with slope of 1:100 is designed to collect the total sewage flow. A rectangular concrete channel with 30cm width and depth is designed to collect rainfall runoff and discharge it based on calculations using Manning's formula.
This document discusses the design considerations for sewer systems. It outlines the different types of sewers based on wastewater flow, and specifies design requirements like pipe sizing, slopes, depths, and velocities. Factors like population equivalent calculations, peak flows, hydraulic properties, and manhole levels are also summarized. The document provides guidance on planning and laying out sewer networks in accordance with relevant codes and standards.
Chapter 9 gravity flow water supply systemGokul Saud
This document provides an overview of gravity flow water supply systems that are commonly used in rural, hilly areas of Nepal. It describes the key components of these systems including various types of intakes, collection chambers, reservoirs, pipelines, and tap stands. It also discusses the feasibility and design process, including assessing community need, conducting surveys, and applying hydraulic principles. Design considerations like avoiding U-profiles in pipelines and using break pressure tanks are also covered.
The objective of our capstone project is to design of storm water management facilities and storage alternatives for a new subdivision. The study area is a 120 hectares land located south of Windsor airport and it is going to be developed into a residential subdivision consist of single houses as well as townhouses. Stormwater management is crucial for both environment and human habitats and it aims to minimize the amount of surface runoff, water pollution, as well as the likelihood of soil erosion. The primary goal of this project is to develop a stormwater management plan for the new subdivision to alleviate the effects of urbanization to storm water and avoid flooding. This can be done by redirecting the stormwater to a nearby natural or artificial wetland, such as ponds, streams, or lakes..
This document lists 50 water resource engineering projects available for students in BE/B.Tech and ME/M.Tech programs through Sree Samarth Project Solution located in Aurangabad, India. The projects cover a wide range of topics related to groundwater analysis, rainwater harvesting, water quality studies, irrigation systems, watershed management, and wastewater treatment. Contact information is provided for students to learn more about specific projects that interest them.
The document discusses airport drainage systems. It explains that a well-designed drainage system is important for safety, efficiency, and pavement durability. The key aspects covered are: 1) Airport drainage systems use surface ditches, inlets, and underground pipes to remove runoff. 2) Estimating runoff involves calculating factors like rainfall intensity and runoff coefficient. 3) Drainage channels and underground pipes are designed using equations like Manning's, with velocities above 2.5 ft/sec to prevent deposits. Inlets are placed at low points with spacings depending on the airport type.
This document discusses the maintenance of water supply mains. It outlines the necessity of maintaining water mains to minimize leakages and ensure sufficient water supply. It describes various leakage detection techniques like direct observation, sounding rods, hydraulic gradient lines, and using waste water meters. It also discusses methods to prevent leaks like proper design, installation of fittings and joints, inspection, and installing water meters. Finally, it presents measures for water conservation like educating the public, installing meters, and inspection.
Draft policy on the regulation of the plumbing sector in Trinidad and Tobago ...Jeffrey James
The document discusses the need for a National Plumbing Policy in Trinidad and Tobago to regulate the plumbing industry and protect public health. It outlines several issues with the current system, including inconsistent practices, training, and lack of licensing and regulation. The proposed policy would establish a regulatory framework through legislation, a dedicated governing body, licensing of plumbers, enforcement of standards, inspections, and public education. It aims to standardize training, qualifications and practices to ensure proper plumbing installation and prevent health and environmental issues.
The study assessed the impact of diamond mining on water quality in the Save and Odzi Rivers in Zimbabwe. Water quality was tested at 10 sites, including reference sites upstream of mining. Results showed high levels of turbidity, total solids, pH, fluoride, heavy metals like iron, chromium and nickel, and bacterial contamination downstream of mines. This pollution poses health and environmental risks and has likely impacted livelihoods by reducing access to potable water and fishing. The water quality declined significantly after mining discharges, classified as "bad" compared to the medium quality at reference sites. Mines need to improve waste management to address the ongoing pollution problems.
The document discusses the use of low impact development (LID) approaches to manage stormwater and mitigate flooding issues. It provides background on LID concepts like bioretention cells, permeable pavements, green roofs, and rain gardens. It then details how the Storm Water Management Model (SWMM) software can be used to simulate the hydrologic performance of different LID controls. The document provides design parameter values for various LID types and guides the user through setting up a SWMM model with LID controls applied to subcatchments to analyze flooding impacts.
Drainage Engineering (Drainage and design of drainage systems)Latif Hyder Wadho
This document provides information on drainage and the design of drainage systems. It discusses the following key points in 3 sentences:
Land drainage and field drainage are the two main types of drainage, with field drainage focusing on removing excess water from the root zone of crops. The main goals of field drainage are to bring soil moisture below saturation to allow for optimal plant growth and to improve soil structure and hydraulic conductivity. The different methods of field drainage include horizontal drainage methods like surface drainage and sub-surface drainage, as well as vertical drainage through tube wells.
The document discusses different types of dams classified by structure and materials, including gravity dams, arch dams, embankment dams, and barrages. Embankment dams, the most common type worldwide, are simple compacted earth structures that rely on their mass to resist forces. The document also describes various embankment dam types such as rock fill dams, concrete-face rock fill dams, and earth fill dams.
internship report on performance of sewage treatment plantAshok Devasani
the report presents a clear description about the performance of 30 MLD sewage treatment plant located in the vicinity of Hyderabad. it also provides a general information of the different sewage treatment process
WEIRS VERSUS BERRAGE
TYPES OF WEIRS
COMPONENT PARTS OF A WEIR
CAUSES OF FAILURE OF WEIRS & THEIR REMEDIES
DESIGN CONSIDERATIONS
DESIGN FOR SURFACE FLOW
DESIGN OF BARRAGE OR WEIR
Design mannual for small scale irrigation scheme bookSurendra Maharjan
This document provides an overview and guidelines for designing small-scale irrigation schemes in Nepal. It was published by the Ministry of Federal Affairs and Local Development in association with HELVETAS Swiss Intercooperation Nepal. The document defines key terms related to irrigation, describes various irrigation techniques like surface, subsurface and sprinkle irrigation. It also outlines the steps involved in project identification, feasibility study, surveys and hydrological analysis. Design guidelines are provided for headworks, canals, sediment control structures, canal structures and cross drainage works. Micro irrigation techniques like pond irrigation, sprinkle irrigation and drip irrigation are also covered. The document aims to provide practical design guidance for small irrigation projects tailored to the local context in Nepal.
SEWAGE TREATMENT PLANT mini project reportNitesh Dubey
This document provides information about a research project analyzing the quality of treated sewage water from shipboard sewage treatment plants. Water samples were taken from 32 ships and analyzed for parameters like coliform bacteria, suspended solids, and biological oxygen demand. The results showed that none of the treated sewage water samples met standards in the MARPOL Annex IV regulations. The document also describes regulations for sewage discharge, potential health and environmental risks of untreated sewage, and common types of sewage treatment systems used on ships.
This document discusses various types of drainage infrastructure used for roads, including culverts, catch basins, gutters, ditches, and drop inlets. It notes that proper road drainage is important for flood control, protecting infrastructure, and environmental impacts. The document is authored by group members Matala Mayambi Tresor, Waseem Akram, and Kanonga Munyungu Arthur.
The document discusses open channel design for both rigid boundary and erodible channels. It describes the key steps in designing trapezoidal channels including determining depth, bed width, side slopes, and longitudinal slope. For rigid boundary channels, the most common design approach is to use Manning's equation to select dimensions that produce non-silting, non-scouring velocities. For erodible channels, two common methods are discussed: the permissible velocity method, which ensures the mean flow velocity is below erosion thresholds; and the tractive force method, which involves equating tractive forces to critical shear stresses of the channel material.
This document summarizes different types of tube wells based on various classification criteria. It describes tube wells as holes bored into the ground to tap groundwater from deep aquifers. Tube wells are classified based on their entry of water, construction method, depth, and type of aquifer tapped. Shallow tube wells are usually less than 60m deep while deep tube wells range from 60-300m deep. Tube wells can be screen wells, cavity wells, drilled wells, driven wells, or jetted wells depending on their construction method. They can tap water table aquifers, semi-artesian aquifers, or artesian aquifers based on the aquifer type.
This document discusses the design of irrigation channels. It covers several key points:
1) The design of irrigation channels involves selecting the channel alignment, shape, size, bottom slope, and whether lining is needed. The design determines the cross-sectional area, depth, width, side slopes, and longitudinal slope.
2) Non-alluvial channels are excavated in soils with little silt, like clay or hard loam. They are designed based on maximum permissible velocity to prevent erosion. Manning's equation or Chezy's equation are used.
3) An example problem demonstrates designing a trapezoidal channel in non-erodible material to carry a discharge of 15 cubic meters per second with a
This document is a graduate report on urban infrastructure prepared by two students for a course at the Sardar Vallabhbhai National Institute of Technology in Surat, India. It discusses various components of a water supply network including collection of water from sources, transmission to a water treatment plant, purification processes at the plant, and distribution of treated water. Diagrams illustrate the flow of water from an intake well drawing from the Tapi River through various treatment units to pumping stations.
This document provides design considerations for a sewerage system for a small township. Key assumptions are made about sewage generation rates and peak flows. Manning's formula and the rational method are used to size sewer pipes and drainage channels. Population calculations are made to determine sewage flows from different areas. Pipes with a diameter of 15cm and slope of 1:85 are designed to collect sewage from individual units. A 22.5cm pipe with slope of 1:100 is designed to collect the total sewage flow. A rectangular concrete channel with 30cm width and depth is designed to collect rainfall runoff and discharge it based on calculations using Manning's formula.
This document discusses the design considerations for sewer systems. It outlines the different types of sewers based on wastewater flow, and specifies design requirements like pipe sizing, slopes, depths, and velocities. Factors like population equivalent calculations, peak flows, hydraulic properties, and manhole levels are also summarized. The document provides guidance on planning and laying out sewer networks in accordance with relevant codes and standards.
Chapter 9 gravity flow water supply systemGokul Saud
This document provides an overview of gravity flow water supply systems that are commonly used in rural, hilly areas of Nepal. It describes the key components of these systems including various types of intakes, collection chambers, reservoirs, pipelines, and tap stands. It also discusses the feasibility and design process, including assessing community need, conducting surveys, and applying hydraulic principles. Design considerations like avoiding U-profiles in pipelines and using break pressure tanks are also covered.
The objective of our capstone project is to design of storm water management facilities and storage alternatives for a new subdivision. The study area is a 120 hectares land located south of Windsor airport and it is going to be developed into a residential subdivision consist of single houses as well as townhouses. Stormwater management is crucial for both environment and human habitats and it aims to minimize the amount of surface runoff, water pollution, as well as the likelihood of soil erosion. The primary goal of this project is to develop a stormwater management plan for the new subdivision to alleviate the effects of urbanization to storm water and avoid flooding. This can be done by redirecting the stormwater to a nearby natural or artificial wetland, such as ponds, streams, or lakes..
This document lists 50 water resource engineering projects available for students in BE/B.Tech and ME/M.Tech programs through Sree Samarth Project Solution located in Aurangabad, India. The projects cover a wide range of topics related to groundwater analysis, rainwater harvesting, water quality studies, irrigation systems, watershed management, and wastewater treatment. Contact information is provided for students to learn more about specific projects that interest them.
The document discusses airport drainage systems. It explains that a well-designed drainage system is important for safety, efficiency, and pavement durability. The key aspects covered are: 1) Airport drainage systems use surface ditches, inlets, and underground pipes to remove runoff. 2) Estimating runoff involves calculating factors like rainfall intensity and runoff coefficient. 3) Drainage channels and underground pipes are designed using equations like Manning's, with velocities above 2.5 ft/sec to prevent deposits. Inlets are placed at low points with spacings depending on the airport type.
This document discusses the maintenance of water supply mains. It outlines the necessity of maintaining water mains to minimize leakages and ensure sufficient water supply. It describes various leakage detection techniques like direct observation, sounding rods, hydraulic gradient lines, and using waste water meters. It also discusses methods to prevent leaks like proper design, installation of fittings and joints, inspection, and installing water meters. Finally, it presents measures for water conservation like educating the public, installing meters, and inspection.
Draft policy on the regulation of the plumbing sector in Trinidad and Tobago ...Jeffrey James
The document discusses the need for a National Plumbing Policy in Trinidad and Tobago to regulate the plumbing industry and protect public health. It outlines several issues with the current system, including inconsistent practices, training, and lack of licensing and regulation. The proposed policy would establish a regulatory framework through legislation, a dedicated governing body, licensing of plumbers, enforcement of standards, inspections, and public education. It aims to standardize training, qualifications and practices to ensure proper plumbing installation and prevent health and environmental issues.
The study assessed the impact of diamond mining on water quality in the Save and Odzi Rivers in Zimbabwe. Water quality was tested at 10 sites, including reference sites upstream of mining. Results showed high levels of turbidity, total solids, pH, fluoride, heavy metals like iron, chromium and nickel, and bacterial contamination downstream of mines. This pollution poses health and environmental risks and has likely impacted livelihoods by reducing access to potable water and fishing. The water quality declined significantly after mining discharges, classified as "bad" compared to the medium quality at reference sites. Mines need to improve waste management to address the ongoing pollution problems.
The document summarizes a study on the public health risks of operations at the Zango Abattoir in Zaria, Kaduna State Nigeria. The following key points were observed:
1) Slow moving abattoir effluent and waste in open drainage systems encouraged bacterial growth and fly proliferation, posing health risks.
2) Lettuce farms near soakaway pits containing decomposing animal remains exposed produce and groundwater to pathogen contamination.
3) Most abattoir workers lacked protective equipment and knowledge of health risks, and medical facilities were insufficient. Unhygienic conditions risked contaminating meat and exposing the public to diseases.
3) Improved waste management, hy
The document proposes a wastewater management system for a new multi-building church complex in Trinidad. It will utilize three independent systems: two Conder Environmental Solutions Techflo SAF 35 packaged sewage treatment plants and one septic tank/soakaway system. The Techflo SAF systems are designed to biologically treat wastewater from the main hall and hostel buildings to surpass local effluent standards. A septic tank and soakaway pit will manage wastewater from the smaller minimart building. Grease traps will pre-treat wastewater from kitchen sinks before discharge.
Hydra Re-Gen is a product that fabricate three performance to your septic system. The product is effecient in clearing blocked drains, removes bad septic smells and effectively meet the expense of aerobic bacteria fight in system. Get more details here: http://septo-air.com/clearing-blocked-drains.html
This document discusses water supply and drainage systems. It covers the types of water supply sources and drainage systems, including public mains, private wells, and different types of private drainage like surface water drainage, greywater drainage, and foul water drainage. It also discusses best practices for drainage pipe installation, materials, sewage treatment, and regulations.
This document provides information about a public information center regarding an investigation into basement flooding and stormwater runoff quality control in Study Area 38. The meeting introduces the project background, study area, potential causes of flooding, possible solutions that will be evaluated, and next steps. Attendees can view displays, ask questions, and provide comment sheets. Potential solutions that will be evaluated include source controls on private property, conveyance controls like road retrofits and local bioretention, and end-of-pipe controls such as wetlands, dry ponds, and underground storage tanks. Criteria for evaluating solutions include environmental, technical, social, and economic factors. The project team will consider public comments received by June 1st and
The document discusses integrating rainwater harvesting (RWH) and stormwater management (SWM) infrastructure. It covers topics such as the need for water harvesting in India due to increasing water stress, the concepts of RWH and SWM, methods of RWH including storage and groundwater recharging, types of SWM techniques, benefits and challenges of an integrated approach, and a case study of New Delhi. The presentation contains 24 slides and references several additional resources on the topics.
This document discusses the key concepts and structures involved in project finance. It outlines the creation of a special purpose vehicle (SPV) as an independent economic entity to complete infrastructure projects. The SPV uses non-recourse debt, equity contributions, and viability gap funding. Risks are allocated between promoters, lenders, contractors and other stakeholders through contractual agreements. The document also covers project evaluation, risk assessment, structuring of financing, and monitoring throughout the development, construction and operations phases.
Guideline for the Preparation of a Concept NoteEEP Mekong
Presentation for the Concept Note Preparation Workshop by EEP Mekong Programme. The workshop was held on the following dates and cities:
19 August 2015 - Yangon
26 August 2015 - Vientiane
8 September 2015 - Hanoi
10 September 2015 - Bangkok
11 September 2015 - Phnom Penh
More information about EEP Mekong and Call for Proposals, please visit www.eepmekong.org
WATER DISTRIBUTION SYSTEM DESIGN REPORT UET LAHORE by envianMuhammad Usman
The report summarizes the design of a water distribution system for a housing society located near Upper Chanab Canal. It describes the study area, land use analysis, basics of water distribution systems, methodology using Hardy Cross and loop software, and design of the water distribution network for the housing society. The design considers grid iron layout, pumping with storage, and continuous water supply. Pipes of 225mm, 100mm and 75mm are proposed for the primary, secondary and tertiary networks respectively. The minimum residual head is set at 14m based on local criteria.
This document discusses the key stages in project formulation and development, including feasibility analysis, design, and analysis. It outlines 10 types of feasibility that should be considered: technical, managerial, economic, financial, cultural, social, safety, political, environmental, and market. The stages of project formulation are described in detail, from initial feasibility analysis through to pre-investment analysis. Developing a detailed project design involves determining the purpose, activities, methods, roles, location, timeline, and presenting a formal proposal. A comprehensive feasibility study evaluates all relevant factors to determine if a project should proceed.
This document discusses excreta and sewage management. It describes that 15% of rural areas lack access to safe excreta facilities, with 75% using pit latrines and 60% discharging waste directly into the environment. Sewage refers to liquid waste containing excreta, bathing, and kitchen waste water. Improper sewage disposal can spread diseases like typhoid, hepatitis A, and cholera. Common rural sewage disposal methods include pit latrines, while water-based systems in other areas use septic tanks connected to soakaways. Proper sanitary sewage disposal prevents contact of feces with vectors and promotes environmental health.
The document discusses various aspects of drainage systems, including:
1) It defines key terms like soil pipe, waste pipe, vent pipe, and rainwater pipe and lists common pipe sizes.
2) It outlines the aims of drainage systems like maintaining healthy conditions and removing waste quickly.
3) It describes traps, their purposes, types, and qualities like being self-cleaning. It also discusses causes of trap seal loss.
4) It provides an overview of drainage pipework systems like two-pipe, one-pipe, single stack, and modified single stack systems.
5) It provides details on septic tanks, including their purpose for areas without main drainage, components, sizing
Separation distances and containment requirements for tanks nfpa 30 2008zaheer sajid
This document summarizes requirements from NFPA 30 2008 for storage of Class I and Class II liquids in aboveground tanks. It provides tables outlining minimum safe distances and containment requirements based on tank type, size, pressure, and protection methods. It also describes controls for spills, requirements for remote impounding and diking of tanks, secondary containment, and fire protection.
Building Services :Drainage, Rain Water Disposal and HarvestingSumit Ranjan
Drainage- Sub- drains, Culverts, Ditches, Gutters, Drop inlets and Catch Basins,Rain Water Disposal for individual buildings, Rain Water Harvesting with examples and illustration for 4th sem.archi. ,P.T.U
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Wasa guidelines for design of water and wastewater systems
1. Reproduction in process by WSSM for Internal Use -Feb 2014
GUIDELINES
FOR
DESIGN AND CONSTRUCTION
OF
WATER AND WASTEWATER
SYSTEMS
IN
TRINIDAD AND TOBAGO
PREPARED BY:-
COMMITTEE OF THE BOARD OF
ENGINEERING OF TRINIDAD AND
TOBACO AND THE WATER AND
SEWERAGE AUTHORITY
JUNE 1995
2. PREFACE
These Guidelines are intended to assist practitioners in the Water and Wastewater
industry in the Design and Construction of these facilities, and in meeting related
statutory requirements in a simple and efficient manner while safeguarding the
health and sanitation of the citizens of Trinidad and Tobago.
They were compiled and revised by a Committee of the Board of Engineering of
Trinidad and Tobago comprising the following members:
Messrs.:
Carl De Four Committee Chairman
Hamilton St. George
Elton Asson
Paul Taylor
Harry Phelps
Amna Sadeek-Tota
John Comacho
The Committee recognizes the invaluable contribution of the Water and Sewerage
Authority and the several persons who participated in developing these guidelines.
3. Part I - Administrative Procedures
Part II - Water
Part III - Wastewater
Part IV - Appendices
4. TABLE OF CONTENTS
DEFINITIONS
PART I - Administrative Procedures
1.1 INTRODUCTION
1.2 OUTLINE APPROVAL
1.2.1 Submission requirements for Outline Approval
1.2.2 Investigations into the availability of water supply and
method of wastewater disposal.
1.3 FINAL APPROVAL
1.3.1 Submission requirements for Final Approval.
1.4 INSPECTION AND COMPLETION CERTIFICATE FOR WATER AND
WASTEWATER SYSTEMS.
1.4.1 Procedure for inspection and issuance of completion
certificate.
1.5 CONNECTION TO WATER AND WASTEWATER SYSTEMS.
1.5.1 Water system
1.5.2 Wastewater system.
PART II - DESIGN GUIDELINES FOR WATER SYSTEMS.
2.1 SCOPE
2.2 GUIDELINES FOR DESIGN OF PIPELINES AND RELATED STRUCTURES
2.2.1 Pipeline
2.2.2 Pipeline Appurtenances
2.2.3 Storage Facilities
2.2.4 Swimming Pool
PART III - DESIGN GUIDELINES - WASTEWATER
3.1 SEWERS AND APPURTENANCES
3.2 SMALL DIAMETER GRAVITY SEWERS
3.3 FORCE MAINS
3.4 WASTEWATER PUMPING STATIONS
3.5 WASTEWATER TREATMENT PLANTS
3.6 ON-LOT WASTEWATER DISPOSAL SYSTEMS
3.7 PROCEDURES FOR CONDUCTING PERCOLATION TEST
3.8 OTHER ON-LOT SYSTEMS
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6. 1
1.1 INTRODUCTION
Under the Water and Sewerage Act Chapter 54 : 40 of the Laws of Trinidad and
Tobago, the approval of the Authority is required for the proposed water
reticulation and wastewater collection, treatment and disposal syst ems for all
developments which involve the sub-division of land and large scale building
developments.
The process of approving applications for building developments by the
Authority is designed to ensure that all building sites are provided with an
adequate supply of potable water, as well as an efficient system of wastewater
collection, treatment and disposal.
Applications submitted are considered in the following stages:
i) Outline Approval
This is approval in principle which indicates the quantity of water
which can be made available to the site and makes
recommendations on the type of wastewater collection, treatment
and disposal system to be installed.
ii) Final Approval
This involves the approval of detailed designs of the water supply
system and wastewater collection, treatment and disposal system
to be installed. This approval must be obtained prior to the
installation of any such facilities.
iii) Inspection and Completion Certificate
All water and wastewater treatment works must be inspected by
the Authority during construction. This will also involve the
conducting and/or witnessing of all tests. On satisfactory
completion, the Authority will issue a Completion Certificate
permitting the use of the wastewater system and the connection
to the water supply system.
7. 2
1.2 OUTLINE APPROVAL
1.2.1 SUBMISSION REQUIREMENT FOR OUTLINE APPROVAL
Applications shall be submitted to the Authority for Outline Approval by a
registered Engineer and must be accompanied by a completed application form
(see Appendix 3 for recommended forms) as well as the following documents:
i) Two (2) copies of the notice of Outline Planning Permission issued
by the Town and Country Planning Division.
ii) Two (2) copies of a Location Plan and Vicinity Map, which would
enable the site to be clearly identified in the field. The Location
Plan should be extracted from the Ward Sheet.
iii) Two (2) copies of a plan of the area showing topographical
information acceptable to WASA.
iv) The estimated water demand for each type of occupancy i.e.
residential, commercial, industrial etc.
v) The proposed method of wastewater collection, treatment and
disposal.
vi) Where the coast, river, swamp, spring and wells are within 30m
from the nearest lot, details of their use are required.
vii) Information on seasonal flooding, flood levels are required.
viii) Where it is proposed that the wastewater be treated at an existing
wastewater treatment plant not owned by WASA, the existing and
proposed load on the plant shall be provided.
ix) Where on-site wastewater treatment with sub-soil disposal is
proposed, the percolation test results will be required by WASA.
8. 3
1.2.2 INVESTIGATIONS INTO AVAILABILITY OF WATER SUPPLY AND METHOD OF
WASTEWATER DISPOSAL.
1.2.2.1 Water Supply
In determining the feasibility of supplying potable water to a development,
the Authority will consider the following:
i) The source of supply
ii) The existing and projected water demand in the area.
iii) The existing and operating conditions and schedules.
iv) The possible alternatives for providing the development with a
potable water supply.
A schematic of the proposed water supply connection will be prepared to
assist the applicant with final design drawings.
1.2.2.2 Method of Wastewater Collection, Treatment and Disposal
The proposed method of wastewater collection, treatment and disposal may
include:
I) Provision of on-lot treatment plant or septic tanks and appropriate
effluent disposal systems.
II) Connection to the public/private sewers.
III) Construction of conventional central collection, treatment and
disposal.
Some of the considerations for determining the appropriate method of
wastewater disposal include:
I) Percolation test results where on-lot sub-soil systems are being
considered.
II) Physical factors - A site visit is necessary to determine physical
factors including location of coast, beaches, river, swamp, the quality
of the receiving waters and well field in relation to the proposed
development.
9. 4
III) Information on seasonal flooding.
IV) Technical feasibility of connection to the public wastewater system.
V) Advice from the Institute of Marine Affairs where developments are in
close proximity to the coast.
VI) Hydrology data from the Water Resources Agency when there is the
possibility of contamination of groundwater supply and surface water
within catchments in use.
VII) Developers should submit their proposals for projects in their entirety
for Outline Approval providing the phasing of the development.
VIII) Operation and maintenance requirements.
IX) Soil conditions.
X) Topography.
XI) Population density in the vicinity of the development .
XII) Size of the development.
1.3 FINAL APPROVAL
1.3.1 SUBMISSION FOR FINAL APPROVAL
Submission for Final Approval should include the following:
1.3.1.1 Water Supply
i) Four (4) copies of plans A - size of proposed water reticulation system
showing lot layout, principal drains, all roads, walkways and reserves,
the location, size of all water supply lines, house connections, sluice
valves, fire hydrants and caps, anchor blocks and other special
fittings.
10. 5
ii) Four (4) copies of Plans A - size showing sections and elevations of all
communal storage tanks and pumping stations. Performance curves of
all pumps must also be submitted.
iii) Four (4) copies of Plans A - size showing details of river, drain, culvert
and sewer crossings; service connections, sluice valves, air valves,
washouts, fire hydrants, valve chambers, anchor blocks, thrust blocks,
and details of connection from the building development to public
water supply.
iv) Data on class of pipes and materials and depth of cover.
v) Calculation sheets, showing design flows, pressures, head losses
systems curves etc.
vi) Structural designs and calculations;
vii) Electrical and mechanical details;
viii) Any other design information, which WASA may require.
1.3.1.2 Wastewater
i) Four (4) copies of plans A - size showing lot layout, principal drains,
all roads, walkways and reserves and layout of the wastewater
collection system showing connections, sizes, gradient of sewers and
distance between manholes invert and top elevations of all manholes
and other appurtenances.
ii) Four (4) copies of plans A - size showing profiles along sewer, showing
ground elevation, invert elevations, manholes, cleanouts, drain
crossings, encasement and special bedding where necessary.
iii) Four (4) copies of plans A - size showing details of all manholes,
cleanouts, house connections, encasement, manhole covers, steps,
supports etc.
iv) Calculation sheets showing depth of flow in sewer at minimum,
average and peak flows, minimum and peak velocities, capacity of
sewer and length, slope and diameter of each section.
11. 6
v) Where a wastewater treatment plant is to be provided, a process
design should be submitted prior to commencement of detailed
design.
vi) Four (4) copies of plans A - size showing detailed designs of
wastewater treatment plant including plans and sections of all process
units, air supply piping, sludge/wastewater piping, electrical and
mechanical details.
vii) Layout of plant on site showing location of pumping facilities, sludge
drying beds, operations building, fence, road reserve, drains, distance
of plant from nearest habitable plot, point of full discharge of effluent
and other pertinent details.
viii) Four (4) copies of plans A - size showing detailed designs of lift
station, sludge drying beds, equipment room, operator’s facilities,
operations building, pumping apparatus, chlorine contact chamber.
ix) Work sheets showing hydraulic and biological designs, computations
for sizing of treatment units and electrical and mechanical equipment
as well as structural design calculations.
x) Detailed manufacturers specifications for all equipment such as
pumps, blowers, chlorinators and other equipment.
xi) Where on-lot disposal systems are proposed:
a. A copy of percolation test certificate issued by the Authority.
b. Four (4) copies of plans A - size of typical lot, showing maximum
building coverage, location of treatment plant or septic tank and
effluent disposal system and outfall effluent drain where
applicable.
c. Four (4) copies of plans A - size showing plans and sections of
septic tank and effluent disposal system including disinfection
facilities where required.
12. 7
d. Work sheet showing design computation for sizing of septic tank
and effluent disposal system.
1.4 INSPECTION AND COMPLETION CERTIFICATE FOR WATER AND WASTEWATER
SYSTEMS
1.4.1 PROCEDURE FOR INSPECTION AND ISSUANCE OF COMPLETION CERTIFICATE
i) Prior to commencement of construction of the water and wastewater
infrastructural works, the applicant submits a work schedule and pays the
relevant inspection fees to the Authority.
ii) These works shall be inspected during construction by a Registered
Engineer who shall be required to certify in writing the quality of the
works. The Engineers Certificate of works will generally be accepted by
the Authority as a basis for granting the necessary approvals.
iii) The role of the Authority will involve occasional inspection of the works
and witnessing and approval of prescribed tests.
iv) A Completion Certificate for the development will be issued by the
Authority upon successful completion of all tests.
1.5 CONNECTIONS TO THE WATER AND WASTEWATER SYSTEMS
1.5.1 Water System
i) Connections to the water system will normally be done by the Authority
at the cost of the developer.
ii) Subject to the approval of the Authority, the developer can make
alternative arrangements for the connections to be made.
13. 8
1.5.2 Wastewater System
All the connections to the public wastewater system must be done by a
licensed sanitary constructor under the supervision of the Authority.
15. 10
DESIGN GUIDELINES FOR WATER SYSTEM
2.1 SCOPE
Design guidelines for the following are included in this section:
2.1 Design factors for pipelines, storage tanks and pump stations.
2.2 Material specifications to ensure that quality requirements are
met.
2.3 Typical details of appurtenances and other related structures.
2.4 Power requirements for pumpsets, identification of acceptable
type of pumps with considerations to quality, reliability,
maintenance, spares etc.
2.2 GUIDELINES FOR DESIGN OF PIPELINES AND RELATED STRUCTURES
2.2.1 PIPELINE
2.2.1.1 General
Pipeline sizes should be determined from estimates of water consumption
and allowable velocity.
2.2.1.2 Water Consumption
Table 2.1 provides estimates of the average daily demand for potable water.
16. 11
Table 2.1
Water Consumption
NO. USER UNIT
TYPICAL (LPD)
CONSUMPTION
1.0 Residential Person 350
2.0 Commercial
2.1 Airport Passengers 11
2.2 Apartment House Person 455
2.3 Automobile Service Station Employee 49
Vehicle Served 38
2.4 Boarding House Person 152
2.5 Department Store Toilet Room 2083
Employee 38
2.6 Hotel Guest 189
Employee 38
2.7 Lodging House & Tourist Home Guest 152
2.8 Motel Guest 111
2.9 Motel with Kitchen Guest 152
2.10 Laundry (Self Service) Machine 2083
Wash 158
2.11 Office Employee 57
2.12 Public Lavatory User 19
2.13 Restaurant (including toilet) Customer 57
Conventional Customer 34
Short Order Customer 23
Bar & Cocktail Lounge Seat 76
2.14 Shopping Centre Parking Space 8
Employees 375
2.15 Theater
Indoor Seat 12
Outdoor Car 15
17. 12
NO. USER UNIT
TYPICAL (LPD)
CONSUMPTION
3.0 Industrial
4.0 Fire Fighting lpm 2275
5.0 Institutional User
5.1 Assembly Hall Seat 12
5.2 Hospital (Medical) Bed 568
Employee 38
5.3 Hospital (Mental) Bed 455
Employee 38
5.4 Prison Inmate 455
Employee 341
5.5 Rest Home Resident 341
Employee 38
5.6 School (Day with Cafeteria)
Gym & Showers Student 95
Cafeteria only Student 57
Cafeteria & Gym Student 38
School (Boarding) Student 284
5.7 Hotels (lcd) 350
Source: (i) Water & Sewerage Authority
(ii) Metcalf and Eddy, Wastewater Engineering, Treatment, Disposal &
Reuse (3rd Edition)
18. 13
Pipelines shall be designed to accommodate a peak flow rate of twice (2) the
average demand for residential, commercial and industrial usage plus the
value estimated for firefighting purposes plus 20% of the total which is
considered as unaccounted for water in the system.
2.2.1.3 Velocity
The velocity of flow in any pipeline whether for the average or the peak
value shall normally be between 0.91 m/s to 1.52 m/s.
2.2.1.4 Head Losses
(a) Friction Loss
Friction loss can be computed using either Hazen Williams formula or
Darcy’s equation.
(b) Minor losses in bends, valves and other fittings should be computed
and included.
For network analysis the Hardy Cross method of design can be utilized to
determine the required pipe sizes.
The minimum size of any distribution pipe line shall be 100mm.
A residual pressure of not less than 170Pa (25psi) should be considered in
the design.
2.2.1.5 Vertical Alignment
Water mains shall follow the general contour of the land.
2.2.1.6 Horizontal Alignment
Water mains shall be laid within the road reserve at a depth of not less than
0.76m below the road surface.
Dual water mains may be installed to avoid water services from crossing the
carriageway.
19. 14
2.2.1.7 Right of Way
A right of way of at least 3.0 metres wide shall be provided for water mains
not located within a road reserve.
2.2.1.8 Location in Relation to Sewers
All water mains shall be placed above sewers so as to ensure a minimum
clearance of 0.45m above the top of the sewer.
2.2.2 PIPELINE APPURTENANCES
2.2.2.1 Gate valves shall be located to ensure that sections of the pipelines and the
development can be locked off without disruption of the total water supply
to other areas. Valves shall be provided for control and isolation purposes in
accordance to:
(a) Pipeline sizes less than 200mm, valves shall be placed at intervals of
500m.
(b) Pipeline sizes greater than 200mm, valves shall be placed at intervals of
1000m.
(c) In all situations valves shall be placed at connection points to the existing
system, at street intersections to facilitate isolations and at dead ends.
2.2.2.2 Air release and vacuum valves shall be located at the highest points. Other
air valves shall be placed at other high points. The size of air valves shall be
in accordance with the relevant AWWA Standards or Approved Equivalent .
2.2.2.3 Washout and pumpouts shall be provided at all low points. In cases where
the ground level is flat a 0.002 grade on the pipeline is required to facilitate
adequate drainage.
2.2.2.4 Fire hydrants spacing shall be located so as to not exceed 90m apart or as
approved by the fire services department.
20. 15
2.2.2.5 Thrust Restraints
All tees, bends, cape, reducers, wyes, valves and hydrants shall be restrained
by either concrete thrust blocks or thrust rods where applicable. Thrust
restraining structures shall be designed in accordance to the relevant AWWA
Standards or approved equivalent.
2.2.2.6 Service Connections
Each plot shall have an individual water service connection not less than
20mm in diameter. Double service connection shall not be permitted.
All water service pipes shall be connected to the water main by means of a
ferrule or corporation valve and shall be laid at a depth of not less than
450mm.
2.2.2.7 Kerb Valves
Kerb valves shall be installed on water service connections outside the
property boundary.
Meter Box
All water service pipes shall terminate just inside the boundary line or
property line with a typical meter box as approved by the Authority.
2.2.2.8 Testing
Testing of water mains and appurtenances shall conform to AWWA Standards
C 600-82. The test pressure shall equal 1.5 times the operating pressure at
the point of testing for two (2) hours.
2.2.3 STORAGE FACILITIES
Central water storage facilities shall be provided for all public, commercial
and industrial buildings and other building developments as stipulated by the
Water and Sewerage Authority.
The water storage tank shall have the capacity equivalent to the average daily
requirement of the establishment.
21. 16
Where applicable central storage facilities are provided they shall be
adequately fenced, illuminated and accessible to vehicular traffic.
2.2.4 SWIMMING POOL
2.2.4.1 General considerations
Design of a swimming pool involves the following factors:
a. capacity of pool
b. daily water requirement
c. estimated evaporation losses
d. change of water
e. total water requirement
f. filter rate and area
g. capacity of recirculation pump
h. turnover duration/recirculation period
i. method of disinfection
2.2.4.2 Detailed Considerations
These include:
a. All for potable use must be obtained from a source approved by the
Authority
b. Fresh water should be introduced into the suction side of the
recirculaton pump, preferably through a make-up water tank. An air
gap not less than 100mm shall be provided.
c. Chlorine residual should be 0.6ppm on the suction side of the
recirculation pump.
d. The recirculaton pump shall be capable of recycling or dewatering the
pool at least once every 6 hours for commercial pools and once every
8 hours for domestic pools.
22. 17
e. Daily partial renewal of clear water should be on average one
twentieth of the total volume of swimming pool water.
f. Pool water shall not be drained into a private or public wastewater
collection system.
g. Swimming pools should not be located less than 3.0m from any
building sewer or septic tank and 7.5m from subsurface wastewater
absorption unit.
DESIGN GUIDELINES - WASTEWATER
3.1 Sewers & Appurtenances
Factors that must be considered in determining the required capacities of
sanitary sewers include:
3.1.1 Sewers shall be designed for the estimated ultimate tributary population.
3.1.2 Sewers are not to be designed for maximum flow i.e. peak flow and
infiltration.
3.1.3 Total contribution population for residential developments shall be 4.5
person per dwelling unit. Population densities for other establishments
as obtained from the Town and Country Planning Division would be
admissible.
3.1.4 Per capita daily contribution of wastewater should be in accordance with
Table 3.1.
3.1.5 The peak flow should be calculated based on the peak factor times the
dry weather flow plus infiltration.
The peak factor shall be calculated based on the formula, peak factor =
where P is population in thousands.
3.1.6 Ground water infiltration should be at 5000 l/ha/day, or based on actual
investigation or established data, if available, in case of existing systems.
23. 18
Table 3.1
Wastewater Consumption
NO. USER UNIT
TYPICAL (LPD)
CONSUMPTION
1.0 Residential Person 280 (170 GPD)
2.0 Commercial (working)
2.1 Airport Passengers 10
2.2 Automobile Service Station Vehicle Served 40
Employee 50
2.3 Bar Customer 8
Employee 50
2.4 Hotel Guest 190
Employee 4
2.5
Industrial Building
(excluding industry & cafeteria)
Employee 55
2.6 Laundry (self service) Machine 2198
Wash 190
2.7 Motel Person 120
2.8 Motel with Kitchen Person 200
2.9 Office Employee 55
2.10 Restaurant Meal 10
2.11 Rooming House Resident 150
2.12 Store (department) Toilet Room 2000
Employee 40
2.13 Shopping Centre Parking Space 4
Employees 40
24. 19
NO. USER UNIT
TYPICAL (LPD)
CONSUMPTION
3.0 Institutional
3.1 Hospital, Medical Bed 78.2
Employee 48
3.2 Hospital, Mental Bed 482
Employee 48
3.3 Prison Inmate 541
Employee 48
3.4 Institutional (school)
School (Day with Cafeteria), Gym &
Showers
Student 96
Cafeteria only Student 72
Cafeteria & Gym Student 48
School (Boarding) Student 336
3.5 Rest Home Resident 421
Employee 48
3.6 Apartment, resort, recreational Person 264
Cabin, resort, cafeteria Person 192
Customer 7
Employee 48
3.7 Campground (development) Person 144
Cocktail Lounge Seat 90
Coffee Shop Customer 24
Employee 48
3.8 Day Camp (No meals) Person 60
Dining Hall Meal Served 36
Dormitory, Bunkhouse Person 180
Hotel, Resort Person 240
Laundromat Machine 2641
Store Resort Customer 12
Employee 48
3.9 Swimming Pool Customer 48
Employee 48
3.10 Theater Seat 12
Visitor Centre Visitor 24
Country Club Member Present 482
Employee 60
25. 20
3.1.7 No public sewers shall be less than 20mm in diameter except where
permitted by the Authority.
3.1.8 All sewers shall be so designed and constructed to give self cleansing
velocities, when flowing full, or not less than 0.6m/s.
3.1.9 Velocities in sewers should not normally exceed 3.00 m/s. Where greater
velocities are attained special provision shall be made to project against
displacement be erosion, abrasion and movement.
3.1.10 Table 3.2 shows the maximum lengths between manholes and absolut e
minimum slopes that should be provided for various pipe sizes. However,
slopes greater than these are desirable:
Table 3.2
Sewer Size
Maximum
Distances/Lengths
Minimum Slope
mm ins m ft. ft./100 ft.-m/100m
200 8 90 300 0.4
250 10 110 350 0.28
300 12 110 350 0.22
350 14 110 350 0.17
375 15 110 350 0.15
400 16 120 400 0.14
450 18 120 400 0.12
525 21 120 400 0.1
600 24 150 400 0.08
3.1.11 Sewers 600mm or less shall be laid with straight alignment between
manholes.
3.1.12 When a sewer joins a larger one, the invert of the larger sewer should be
lowered sufficiently to maintain the same energy gradient.
3.1.13 Pipe material shall be of PVC or concrete or any other material as
approved by the Authority.
a) PVC - All PVC pipe shall be manufactured according to BS 5481 or
approved equivalent international standard;
26. 21
b) Concrete - concrete pipes shall be manufactured to meet the
requirements of BS 556 or approved equivalent international
standard.
3.1.14 Manholes shall be installed at the upper end of each line, at all changes
in grade, size or alignment, at all inter-sections and in accordance with
distances at Table 3.2. A drop manhole should be provided for a sewer
entering a manhole at an elevation of 0.6m or more, above the manhole
invert. Where the difference in the elevation between the incoming and
the manhole invert is less than 0.6m, the invert should be filleted to
prevent solids deposition. The minimum diameter of manholes should be
1.2m. Solid and watertight manhole covers are to be used in all cases.
Manhole covers shall be fitted with a gasket to the approval of the
Authority. Manholes should be constructed of precast reinforced
concrete cylinders. The base of the manhole shall be such as to permit
the flushing of solids. Sulphate resistant cement shall be used in the
construction and installation of the manhole bases. The design, spacing
and materials for manhole steps shall be approved by the Authority.
3.1.15 There shall be no physical connection between a public or private potable
water supply system and a sewer. Sewers should be laid at least 3.0m
horizontally from any existing or proposed water main. Whenever sewers
cross under water mains, the sewer shall be laid at least 3.0m
horizontally from any existing or proposed water main. Whenever sewers
cross under water mains, the sewer shall be laid at such elevation that
the top of the sewer is at least 0.45m below the bottom of the water
main.
3.1.16 In roadways where cover is less than 1.2m or in open areas where cover
is less than 0.9m, the pipe shall be structurally reinforced to perform as a
rigid pipe system.
3.1.17 The top of a sewer shall be at least 0.6m below the bottom of any drain it
crosses. Where this distance is less than 0.6m, the sewer shall be encased
in concrete.
3.1.18 A right-of-way at least 3.0m wide shall be provided for sewer mains not
located within a road reserve.
27. 22
3.2 SEWER DIAMETER GRAVITY SEWERS
3.2.1 Where small diameter gravity sewers are permitted the EPA Manual
Alternative Wastewater Collection Systems, the design of small bore
sewer systems by R. J. Otis and D. Duncan Mara, or any other standard
acceptable to the Authority shall be used.
3.2.2 The minimum pipe diameter shall not be less than 100mm.
3.2.3 The minimum design velocity of 0.46 m/s at half full pipe shall be used.
3.3 FORCE MAINS
Considerations for velocity and friction losses in the Design of Force
Mains shall be similar to those applied to the design of water mains. The
minimum size of force main is 100mm.
3.4 WASTEWATER PUMPING STATIONS
3.4.1 Pumping stations shall be designed to handle peak flows with 100%
standby capacity.
3.4.2 The wetwell shall provide a minimum holding period of 10 minutes for
the design flow.
3.4.3 Pumps should be sized and operated so that their rate of discharge is
nearly equal to the rate of flow into the wetwell.
3.4.4 A coarse screen shall be provided before the wetwell. Adequate
provisions must be made for the removal and disposal of screenings.
3.4.5 Pumping stations must be provided with standby power generating units.
3.4.5 In areas affected by seasonal flooding, precautionary measures shall be
taken to guard against flooding of the wetwell.
3.4.7 Safe access shall be provided for dry and wet wells to allow for
inspection and maintenance.
28. 23
3.4.8 Adequate ventilation must be provided.
3.4.9 The distance between the compound of a pumping station and a
residential building shall not be less than 50m.
3.4.10 The installation shall have paved vehicular access, surface drainage,
security lights and shall be adequately fenced.
3.4.11 A potable water supply must be provided including a 4000 litre storage
tank with a pump capable of delivering a minimum of 90 lpm at convert
to in head 30m head.
3.5 WASTEWATER TREATMENT PLANTS
3.5.1 The standard for domestic effluent shall be the Trinidad and T obago
Bureau of Standards (TTBS - 417 : 1993) - “Specifications for Liquid
Effluent from Domestic Wastewater Treatment Plants into the
Environment”. This standard has been compulsory status. Appendix 3
refers.
3.5.2 The standard for all other wastewater effluents (Municipal, commercial,
agricultural etc.) shall be the World Health Organization (WHO)
Standards, or any other standards acceptable to the Authority.
3.5.3 Table 3.3 provides tolerance limits for industrial effluent discharged into
public sewers.
29. 24
TABLE 3.3
TOLERANCE LIMITS FOR INDUSTRIAL EFFLUENTS BEING DISCHARGED INTO PUBLIC
SEWERS.
ITEM
NUMBER
CHARACTERISTIC
TOLERANCE LIMITS
INTO PUBLIC SEWERS
1 Colour & Odour -
2 Suspended Solids, mg/l, max. 350
3 Particle size of suspended solids, mm 3
4 Dissolved Solids (inorganic), mg/l max. 2100
5 pH value 5.5 to 9.0
6 Temperature, O
C, max.
4.5 at the point of
discharge
7 Oil, grease, mg/l, max. 20
8 Total residual chlorine, mg/l, max. -
9 Ammoniacal nitrogen, (as N), mg/l, max. 50
10 Total nitrogen (as N), mg/l, max. -
11 Free ammonia (as NH3 ), mg/l, max. -
12 Biochemical oxygen demand (5 days at 20O
, max.) -
13 Chemical oxygen demand, mg/l, max. 300
14 Arsenic (as As), mg/l, max. 0.2
15 Mercury (as Hg) mg/l, max. 0.01
16 Lead (as Pb), mg/l, max. 1
17 Cadmin (as Cd), mg/l, max. 1
31. 26
3.5.4 The Authority may consider any technically feasible method of
wastewater treatment providing it can produce effluent of the required
quality and which can satisfy the Authority’s other requirements such as
location. All relevant references must be provided.
3.5.5 Treatment plants are to be located downwind of all residential premises.
Treatment tanks shall not be located less than 50m from habitable
premises. Where treatment is done at waste stabilization ponds the
distance from the pond to any habitable premises shall not be less than
100m. A thick green belt (for example, tall pine trees) shall be provided
between the pond and the habitable premises.
3.5.6 Fencing and lighting of Wastewater Treatment Plants shall be provided.
3.5.7 Adequate land shall be provided for the treatment facilities including
additional land area for future plant expansion.
3.5.8 The treatment facilities shall be made accessible to vehicular traffic.
Paved roadways, including on-site vehicular parking and paved walkways
between treatment units and buildings must be provided.
All treatment units shall be provided with service access - steps/ladders,
cat walks and handrails. All works must be painted.
3.5.9 Adequate accommodation by means of a room equipped with storage
cupboards, lavatory
3.5.10 A potable water supply must be provided, including- a 4000 litre water
storage tank with a pump capable of delivering a minimum of 90 lpm at
30 m pressure.
32. 27
3.5.11 Treatment plants shall be provided with laboratory facilities.
3.6 ON-LOT WASTEWATER DISPOSAL SYSTEMS
3.6.1 Where on lot wastewater disposal systems are permitted the following
manual may be used:-
(a) EPA Design Manual ‘On-Site Wastewater Treatment and Disposal
System’
(b) the Trinidad and Tobago Bureau of Standards - T.T.S 16 80 400
(c) or any other standard acceptable to Water and Sewerage Authority
shall be used.
3.6.2 On-Lot systems shall be constructed in accordance with approvals of the
Authorities (Local Health, WASA) and may be used where no public or
private sewerage system is:
i. available within 50m (150 ft.) or
ii. likely to become available within a reasonable time.
3.6.3 The on-lot disposal system shall be designed to receive all domestic
wastewater from the building.
3.6.4 Storm-water, wastewater from a commercial water softener, water filter,
or other commercial water treatment device or commercial or industrial
process, wastes shall not be discharged into an on-lot system designed to
receive sanitary sewage.
3.6.5 Sewage or sewage effluent shall not be discharged into:
i. a drilled, bored or dug well
ii. an aquifer
iii. an excavation, seepage pit or cesspool deeper than 3.66m (12 ft.)
from the surface; or
iv. an abandoned water well
3.6.6 An absorption system shall not normally be located under
i. a roadway or driveway
33. 28
ii. a paved road
iii. a vehicle parking lot
iv. any building
TABLE 3.4
Minimum distance for location of
On-Site/Lot Wastewater Systems
FEATURE
SEPTIC
TANK
METRE
ABSORPTION
UNIT METRE
Building 1.50 3.00
Property Boundary 1.50 1.50
Wells, Springs or any water source 30.00 30.00
Potable Water Pipes 7.50 3.00
* Cuts or Embankments 3.00 30.00
Paths 7.50 1.50
Swimming Pools 1.50 7.50
Shore line / high-water mark 3.00 30.00
Underground Water Storage Tank 30.00 15.00
Large trees 7.50 1.50
Septic Tank 1.50 1.50
Soakaway 1.50
Note
* Ground Water Level 1.20 1.20
Notes:
* These distances should be increased to 60
meters, if the installation is on a water
supply watershed.
* The minimum clearance between the
bottom of an absorption unit and the ground
water level.
34. 29
3.6.7 Table 3.4 gives details of minimum distances for location of On -Lot
Wastewater Systems from various features
3.7 PROCEEDURE FOR MAKING PERCOLATION TEST
3.7.1 Where the effluent of an on-lot system is to be disposed of in a sub-
surface system, the design of the system shall be based on the results of
a Percolation Test performed in keeping with the building procedures
Percolation tests shall be conducted under the supervision of the Water
and Sewerage Authority. A test certificate shall be issued following these
tests.
These tests ascertain the suitability of a receiving soil to, absorb effluent
from an on-lot: system.
Prior to the percolation tests, a subdivision/site plan for the proposed
development showing contours at 1m or 2m intervals should if required,
be submitted to the Water and Sewerage Authority and/or the Approving
Authority for locating test points
3.7.2 Location and Number of test holes
The test shall be conducted at points where the disposal units (soakaway
pit and or absorption trenches) are to be located.
A minimum of three shall be bored or dug across the test area.
At least one hole shall be bored or dug to a depth of about 3m at the
lowest site elevation in order to determine the existence of ground water
or impervious strata.
3.7.3 Preparation of test holes
Each hole shall have a diameter or side width respectively of 150 to
300mm and vertical sides to a depth of the proposed soakaway pit or
absorption trench (min. depth 1.3m)
35. 30
The bottom and sides of the holes shall be carefully scratched in order to
remove any smeared soil surface and to provide a natural soil/water
interface into which water may percolate.
All loose material shall be removed from the bottom of the holes and
coarse sand or fine gravel shall be added for a depth of about 50mm to
protect the bottom of the holes from scouring and sediment
3.7.4 Soaking Period
Carefully fill the holes with at least 300mm of clear water above the
Gravel or sand or to a height where the water surface is visible and leave
overnight to allow ample opportunity for soil swelling and saturation.
The percolation test shall be determined 24 hours after the water is
added
3.7.5 Measurement of Percolation Rate
Adjust the water level to 300mm above the gravel or sand. From a fixed
reference point the drop in water level is noted over a 120 minutes
period at intervals 30 minutes.
After each measurement the water level is adjusted to the 300mm level.
The last water level drop is used to calculate the percolation rate.
In sand/porous soils with little or no clay, soaking may not be necessary.
If after filling the holes twice with 300mm of water, water seeps
completely away in less than 10 minutes, the test can proceed
immediately.
From a fixed, reference point the drop in water level shall be noted over
a 60 minutes period at intervals of 10 minutes adjusting the water level
to 300mm after each measurement. The last water level drop is used to
calculate the percolation rate.
36. 31
3.7.6 Calculation of Percolation Rate
The percolation rate is the time taken, in minutes, for the water level in a
test hole to fall 25mm. To determine the percolation rate for the area,
the rates obtained for each hole are averaged. If the rates in area vary by
more than 20 minutes/25mm, variations in the soil type are indicated.
Under these circumstances percolation rates should not be averaged.
3.7.7 Interpretation of Results Absorption System Percolation Rate
Slower than 30 min./25mm Unsuitable for soakaway
Slower than 60 min./25mm Unsuitable for absorption
trenches
3.7.8 The final choice of which wastewater disposal system is adopted in a
particular case will depend on many factors.
3.7.9 Absorption - Area Requirements
For Private Residences
PERCOLATION RATE (TIME
REQUIRED TO FALL 25MM IN
MINUTES)
REQUIRED ABSORPTION AREA
SQUARE METERS PER BEDROOM FOR
BOTTOM ABSORPTION TRENCHES OR
SIDE WALL FOR SOAKAWAY PITS
1 or less 6.5
2 7.9
3 9.3
4 10.7
5 11.6
10 15.3
15 17.6
30 23.2
45 27.9
60 30.7
37. 32
3.7.10 Table 3.4 provides details of minimum distances for location of on -lot
Wastewater systems
3.8 Other On-Lot Systems
Where percolation rates do not permit sub-soil disposal of wastewater
effluent the following on-lot systems may be used. These include:
(a.) Evapo-transpiration system including use of the mound system
(b.) Use of separate dual system
38. Guidelines for Design and Construction of
Water and Wastewater Systems in Trinidad and Tobago Page 1
APENDIX I
39. Guidelines for Design and Construction of
Water and Wastewater Systems in Trinidad and Tobago Page 2
APPENDIX 1
4.0 MECHANICAL & ELECTRICAL GUIDELINES
4.1 GENERAL
4.1.1 The installations shall have paved vehicular access, surface drainage,
security lights and shall be adequately fenced.
4.1.2 A minimum of one (1) metre working space is to be provided around blowers,
Iift pumps, sludge pumps and standby generators.
4.1.3 Adequate lifting equipment is to be provided for all pumps as well as
blowers rated at 15 Hp and larger.
4.1.4 Wastewater pump stations and treatment plants shall be designed to handle
peak flows with 100% standby capacity including blowers, lift pumps and
sludge/recirculating pumps.
4.1.5 All installations shall be designed to allow for unmanned operations
4.2 ELECTRICAL POWER/LIGHTING REQUIREMENT FOR WATER AND WASTEWATER
INSTALLATION
4.2.1 GENERAL
4.2.1.1 The character for the electrical power supply to these installations shall be
400V, 3 phase, 60Hz, 4 wire or 230 V, 1 pH, 60 Hz.
4.2.1.2 These installations shall conform to the requirements of the Trinidad and
Tobago National Electrical code as administered by the Electrical
Inspectorate of the Trinidad and Tobago Electricity Commission.
4.2.1.3 A single phase step down 230V/115V transformer shall be installed to
115Vfor socket outlets and possible lighting.
40. Guidelines for Design and Construction of
Water and Wastewater Systems in Trinidad and Tobago Page 3
4.2.1.4 Adequate layout lighting shall be provided where a starter house is used
adequate internal fluorescent lighting shall be provided and at least two
(120V/115V) electrical outlets.
4.2.1.5 External lights shall be controlled by photo electric sensors.
4.2.2 WASTEWATER PLANTS - ELECTRICAL POWER
4.2.2.2 A standby generator shall be provided for at least fifty percent (50%)
pumping capacity, surface aerators/blower capacity recirculating pu mps as
well as emergency lighting equipped with auto transfer switches
4.3 MOTOR REQUIREMENTS
4.3.1 Motors shall operate at the above power supply and shall be vertical or horizontal,
weather proof and vermin proof.
4.3.2 Motors shall be rated to drive pumps for the full range of flows and heads.
4.3.3 Motors shall be rated to be able to operate in tropical countries.
4.3.4 Motor thrust bearings shall have capacity to carry the weight of all the rotating
parts plus the hydraulic thrust of the pump impellers and have ample safety factor.
The factor shall be based the average life expectancy of five years’ operating at 24
hours per day.
4.3.5 The motor shall be of the full voltage starting, vertical hollow shaft, squirrel cage
induction type
4.3.6 The motor speed shall not exceed 1800 rpm for motors larger than 30 Hp (no load)
41. Guidelines for Design and Construction of
Water and Wastewater Systems in Trinidad and Tobago Page 4
4.4 MOTOR STARTER/CONTROL REQUIREMENTS
4.4.1 Starters shall conform to the latest HEMA Class II type B standards, the
requirements of the Trinidad and Tobago Electrical Inspectorate, and the
requirements of the Trinidad and Tobago Electricity Commission
4.4.2 Starters shall be of the reduced voltage type unless otherwise approved in writing
by T&TEC.
SUBJECT STANDARD
Storage Tanks
Welded Steel Tanks ANSI/AWWA D100-84
Painting for Welded Steel Tanks ANSI/AWWA D102-78
Factory Coated Tanks ANSI/AWWA D103-80
Disinfection ANSI/AWWA D652-86
Concrete Structures for retaining liquids AS 3735 1991
Pipelines
Polybutylene (PB) AWWA C-902-78
Polyethylene (PET) AWWA C-901-78
Poly Vinyl Chloride (PVC) AWWA C-900-75
Fabricated Steel Pipe and Fittings AWWA C-208-83
Steel Pipe Flanges Class D AWWA C-207-86
Coal tar protection coatings and linings for steel
water pipelines
AWWA C-203-86
Flanged Ductile Iron Pipelines AWWA C-1l5/A21
Rubber Gasket AWWA C-111/A21
Disinfection AWWA C-651-86
Pressure Test AWWA C-600-82
Grey Iron casting BS 1452:1977
Elastomeric Joint Rings for pipework and pipelines BS 2494:1986
Flanges and bolting for pipes valves and fittings
metric series (copper alloy and composite flanges)
BS 4504: Part 2 1974
Metal Washers for General Engineering purposes
metric series
BS 4320:1968
Specifications for Poly Vinyl Chloride (PVC) Solvent
Cement for use with unplastized PVC Pipes and
fittings for cold water applications
TTS 413-1992
Cast Iron Non-pressure pipes and pipe fittings metric
units
AS 1631-1974
42. Guidelines for Design and Construction of
Water and Wastewater Systems in Trinidad and Tobago Page 5
SUBJECT STANDARD
Valves
Balls Valves AWWA C-507-35
Rubber Sealed Butterfly Valves BS 2494:1986
Sluice Valves AWWA C-501-56
a) Water Service Connections
b) Fire Hydrant
c) End Cap
d) Washout
e) Valve Chamber and Assembly
f) Trench Cross Section
g) Culvert Crossing
h) Thrust Block
Predominately key Operated Cast Iron Valve for
waterworks purposes
BS1 5163:1986
Butterfly Valves BS 5155:1984
Copper Alloy Gate Valve and Non-Return Valve
for use in water supply and hot water services
AS 1628: 1917
43. Guidelines for Design and Construction of
Water and Wastewater Systems in Trinidad and Tobago Page 1
ABSORPTION RATES
Percolation Rate
[time taken for water
level to drop 25mm]
(minutes)
Required Absorption Area
m2
per 1000 l per day m3
/m2
/day
2 or less 12.1 0.0830
3 14.6 0.0708
4 17.1 0.0585
5 18.4 0.0543
6 19.5 0.0516
7 20.6 0.0489
8 21.7 0.0462
9 22.8 0.0435
10 24.5 0.0408
11 25.2 0.0397
12 26.0 0.0386
13 26.7 0.0375
14 27.5 0.0364
15 28.2 0.0354
16 28.8 0.0349
17 29.3 0.0343
18 29.8 0.0338
19 30.3 0.0332
20 30.8 0.0327
21 31.3 0.0321
22 31.8 0.0316
23 32.3 0.0310
24 32.8 0.0305
25 33.3 0.0299
26 33.8 0.0294
45. Guidelines for Design and Construction of
Water and Wastewater Systems in Trinidad and Tobago Page 3
57 48 0.0208
58 48.3 0.0207
59 48.6 0.0206
60 48.9 0.0204
over 60 Unsuitable for shallow absorption systems