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Water supply, sanitation and rainwater harvesting

  2. 2. WATER SUPPLY A water supply system or water supply network is a system of engineered hydrologic and hydraulic components which provide water supply.
  3. 3. A water supply system typically includes:  A drainage basin  A raw water collection point (above or below ground) where the water accumulates, such as a lake, a river, or groundwater from an underground aquifer.  Water purification facilities.Treated water is transferred using water pipes (usually underground).  Water storage facilities such as reservoirs, water tanks, or water towers.Tall buildings may also need to store water locally in pressure vessels in order for the water to reach the upper floors.  Additional water pressurizing components such as pumping stations .  A pipe network for distribution of water to the consumers.  Connections to the sewers (underground pipes, or aboveground ditches).
  5. 5. DIRECT PUMPING SYSTEM  Tanks must be sufficiently elevated to achieve required pressure. For proper operation of the system, the gravity tank is located at least 30 ft or 10 m above the highest outlet or consumer. In tall buildings it's necessary to use pressure reducing valves in the lowest floors before the fittings.
  6. 6. ADVANTAGES  Extreme simplicity : There are no complicated or sophisticated controls  Most Reliable : It is the only system which has a available in the event of the power or water supply failure  Economical: Operating costs are much less and capital is usually no higher than other systems.  Minimum maintenance: Only requirement beyond terms is periodic cleaning and possible repainting of the tank.  Fewer pressure regulating valves are required for the control system  Provides additional reserve capacity for fire protection while domestic water is available in addition to the fire reserve.  Use less energy
  7. 7. DISADVANTAGES  The tank must be elevated. Provision must be made on the roof of the building to support the tank. A tank on the roof is unslightly and if it is enclosed and dressed up, there is additional architectural expense.  The weight of the water and the tank can increase the structural costs.  Tanks require maintenance, periodic cleaning and painting Is required.  If the tank ruptures. A large quantity of water is released which may cause damage.
  8. 8. OVERHEAD TANK SYSTEM  Overhead tanks ensure both water pressure and water supply in case of power failure.  This solution requires pressure reduction valves on each floor in order to avoid undesired high static pressures at the tap, which creates unacceptable noise while tapping.  In this model the upper six floors require a separate booster system in order to create sufficient pressure.  The static pressure there is too low due to the insufficient geometric height to the roof tank.
  9. 9. ADVANTAGES  Mature technology  Only one discharge from booster set to top  Space saving  Less sensitive to electricity fall-outs DISADVANTAGES  Water is pumped past where it’s required  Insufficient pressure on the uppermost floors  Excessive pressure on the lowest floors  Pressure reduction valves have to be fitted  Need for higher pressure grade of pipe work  Space requirement for tank  Risk of microbiological growth in roof tank
  10. 10. HYDRO PNEUMATIC SYSTEM  Is a modernization of the older gravity tank method of water supply. Its main purpose is to control or boost a limited supply pressure to a higher or more uniform value so that a continuous and satisfactory water supply will be available at all fixtures within the system.
  11. 11. ADVANTAGES  Does not have to be elevated  Can be located anywhere in the building.  Can save valuable space by being located outside the building  It is not exposed to the outer elements. DISADVANTAGES  Inside corrosion of tank and piping is danger due to addition of air in the tank.  A pressure variation of 20 psi is normal in the system pressure.  Pumps of higher head are required.  Higher initial and operating costs than gravity system due to pressure vessel type tank, higher head pumps and more sophisticated controls.  May take valuable space in the basement or other area.
  12. 12. Hot water System Solar Heating System Local Heating System
  14. 14. "Sanitation generally refers to the provision of facilities and services for the safe disposal of human urine and feces.The word 'sanitation' also refers to the maintenance of hygienic conditions, through services such as garbage collection and wastewater disposal.“ WHAT IS SANITATION?
  15. 15. DESIGN CONSIDERARTIONS To achieve this aim a drainage system shall satisfy the following requirements: a) rapid and efficient removal of liquid wastes without leakage; b) prevention of access of foul gases to the building and provision for their escape from the system. c) adequate and easy access for clearing obstructions; d) prevention of undue external or internal corrosion, or erosion of joints and protection of materials of construction; e) avoidance of air locks, proneness to obstruction, deposit and damage.
  16. 16. Efficient and an economical plumbing system can be achieved by planning the toilets in compact grouping with the layout of the bathrooms and observing the following guidelines: a) Placing of plumbing fixtures around an easily accessible pipe shaft; in high rise buildings the pipe shafts may have to be within the building envelope and easy provision for access panels and doors should be planned in advance, in such cases. b) Adopting repetitive layout of toilets in the horizontal and vertical directions. c) Avoiding any conflict with the reinforced cement concrete structure by avoiding embedding pipes in it, avoiding pipe crossings in beams, columns and major structural elements. d) Identifying open terraces and areas subject to ingress of rainwater directly or indirectly and providing for location of inlets at each level for down takes for disposal at ground levels. e) Avoiding crossing of services of individual property through property of other owners. f) Planning to avoid accumulation of rain water or any backflow from sewers particularly in planned low elevation areas in a building.
  17. 17. g) Soil and waste stacks in a building having more than 10 branch intervals shall be provided with a relief vent at each tenth interval counting from the top floor.
  18. 18. TYPES OF DRAINAGE SYSTEMS i. single stack system, ii. one‐pipe system, iii. two‐pipe system.
  19. 19. SINGLE STACK SYSTEM 1)The single stack system (without any vent pipe) is ideal when the toilet layouts are repetitive and there is less space for pipes on the wall. 2) In any system so selected there should be not more than two toilet connections per floor. 3)The system requires minimum 100 mm diameter stack for a maximum of five floors in a building.
  20. 20. SAFEGAURD OF SINGLE STACK SYSTEM a) as far as practicable, the fixtures on a floor shall be connected to stack in order of increasing discharge rate in the downward direction; b) the vertical distance between the waste branch (from floor trap or from the individual appliance) and the soil branch connection, when soil pipe is connected to stack above the waste pipe, shall be not less than 200 mm; c) depth of water seal traps from different fixtures shall be as follows: Water closets 50 mm Floor traps 50 mm Other fixtures directly connected to the stack. 1) Where attached to branch 40 mm waste pipes of 75 mm dia or more 2)Where attached to branch 75 mm waste pipes of less than 75 mm dia
  21. 21. d) branches and stacks which receive discharges fromWC pans should not be less than 100 mm, except where the outlet from the siphonic water closet is 80 mm, in which case a branch pipe of 80 mm may be used. For outlet of floor traps 75 mm dia pipes may be used; e) the horizontal branch distance for fixtures from stack, bend(s) at the foot of stack to avoid back pressure as well as vertical distance between the lowest connection and the invert of drain f) for tall buildings, ground floor appliances are recommended to be connected directly to manhole/inspection chamber.
  22. 22. ONE-PIPE SYSTEM 1)This system is suitable for buildings where the toilet layouts and the shafts are repetitive. It requires less space, and is economical. 2) Continuous flow of water in the pipe from waste appliances makes it less prone to blockage and makes the system more efficient. 3)The system eliminates the need for a gully trap which requires constant cleaning. 4)The system is ideal when the main pipes run at the ceiling of the lowest floor or in a service floor.Two-pipe system may present space and crossing problems which this system eliminates.
  23. 23. TWO-PIPE SYSTEM 1)This system is ideal when the location of toilets and stacks for the WCs and waste fittings is not uniform or repetitive. 2) In large buildings and houses with open ground and gardens the sullage water from the waste system can be usefully utilized for gardening and agriculture. 3) In larger and multi-storied buildings, the sullage is treated within the building for re-use as makeup water for cooling towers for air conditioning system and is also used for flushing water-closets provided it has absolutely no connection with any water supply line, tank or system used for domestic and drinking supply.
  24. 24. SEPTIC TANKS Septic tank(s) discharging into either a subsurface disposal field or one or more seepage pits shall be required for the approval of drainage and sanitation plans for the places where public sewers are not available.
  25. 25. Pre- Treatment Primary Treatment Secondary Treatment Tertiary Treatment Pre-treatment removes materials that can be easily collected from the raw waste water before they damage or clog the pumps and skimmers of primary treatment clarifiers (trash, tree limbs, leaves, etc.). It Includes  Screening  Grit removal  Flow equalization  Fat and grease removal Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. The settled and floating materials are removed and the remaining liquid may be discharged or subjected to secondary treatment. Secondary treatment removes dissolved and suspended biological matter. Secondary treatment is typically performed by indigineous, water- borne micro- organisms in a managed habitat. Tertiary treatment provides a final treatment stage to the effluent quality to the desired level . SewageTreatment Plant Treated Water Tank Non Potable water Tank for Fishing & Irrigation Over Flow to Municipal Sewer
  26. 26. Rainwater Harvesting  Rainwater harvesting is the accumulation and deposition of rainwater for reuse on- site, rather than allowing it to run off.  The rainwater collected can be stored for direct use or can be recharged into the underground aquifers its uses include water for gardens, livestock, domestic use with proper treatment, and indoor heating for houses etc.  The harvested water can also be used as drinking water, longer-term storage and for other purposes such as groundwater recharge.  The Central Ground Water Authority (CGWA) has made rainwater harvesting mandatory in all institutions and residential colonies in notified areas (South and southwest Delhi and adjoining areas like Faridabad, Gurgaon and Ghaziabad). This is also applicable to all the buildings in notified areas that have tube wells. The CGWA has also banned drilling of tube wells in notified areas.
  27. 27. Importance of Rainwater Harvesting The importance of developing rainwater harvesting system are briefly given below in points:-  The gathered rainwater can be used for agricultural purposes. The environment may be helped to get rid of the tendency to drought.  The requirement of water for feeding the live-stocks can be met.  The ever-increasing demand for water can be satisfied.  The quantity of the subterranean water can be increased.  Wastage of water flowing through drain, gutter, or any water-cause can be stopped and damage to water-course of any type may be stopped.  Water-logging on roads and thoroughfares can be checked and localities can be saved from being inundated.  The quantity of water can be raised and soil erosion can be checked.
  28. 28. Formula for calculating amount of water collected Total quantity of water to be collected (cuM) = [Roof Top Area (sqM) x Average Monsoon Rainfall (M) x 0.8]
  29. 29. Rainwater Harvesting Techniques  Surface runoff harvesting  Roof top rainwater harvesting
  30. 30. Surface Runoff Harvesting:- In this method the rainwater is accumulated in a small constricted area like pits, wells, trenches, shafts etc. and infiltrated under the soil through them. This is the indirect method of rainwater harvesting so there is no direct gain but in long-term this is the best method of making water available sufficient under the ground. This method of rainwater harvesting is also called recharging ground water aquifer.  There are different methods of recharging ground water aquifers. Some of them are:-  Recharging of bore holes  Recharging through wells  Recharging through pits  Recharging through trenches  Recharging through shafts  Recharging making percolation tanks
  31. 31. Process of Surface Runoff Harvesting:-  Well is constructed in such a place that maximum rainwater accumulate to that area or it can be chosen among the abandoned wells for the recharging or even wells can be constructed to recharge the drainage (storm) water i.e. connecting the drainage pipes to the wells.  But before water enters to the well it is very necessary to filter the water so that clean water gets recharged and no more sediments will settle inside the well. For this near the well the filter media is constructed and then the filtered water is only allowed to enter into the well.
  32. 32. Roof Top Rain Water Harvesting  Rooftop Rain Water Harvesting is the technique through which rain water is captured from the roof catchments and stored in reservoirs.  Harvested rain water can be stored in sub-surface ground water reservoir by adopting artificial recharge techniques to meet the household needs through storage in tanks.  The Main Objective of rooftop rain water harvesting is to make water available for future use. Capturing and storing rain water for use is particularly important in dryland, hilly, urban and coastal areas.  This method is less expensive and very effective and if implemented properly helps in augmenting the ground water level of the area.
  33. 33. Components of Rooftop Rainwater Harvesting A roof top rainwater harvesting system consists of:  Roof Catchment  Gutters  Down pipes  Rain water/ Storm water drains  Filter Chamber  Storage Tanks/ Pits/ Sumps.  Ground Water recharge structures like pit, trench, tube well or combination of above structure.
  34. 34. ADVANTAGES OF RWH  Simple Construction - The construction of rainwater collection systems is not complicated and most people can easily build their own system with readily available materials.  Ease of Maintenance - The operation and maintenance of a household rainwater collection system is controlled by the individual without having to rely upon the maintenance practices of a municipally controlled water system  Water Quality - Rainwater is generally one of the better sources of an alternate water supply when compared with other sources of water that may be available.  Convenience - Rainwater collection provides a convenient source of water at the immediate place where it will be used or consumed.  Systems are Flexible and Adaptable - Rainwater collection systems can be adapted to suit most individual circumstances and to fit most any household’s budget.
  35. 35. DISADVANTAGES OF RWH  High Initial investment Costs - The main cost of a rainwater collection system generally occurs during the initial construction phase and no benefit is derived until the system is completed.  Regular Maintenance - Regular maintenance, cleaning and repair will be required for the operation of a successful rainwater collection system.  Vulnerable Water Quality - The quality of rainwater can be affected by air pollution, insects, and dirt or organic matter. The type and kind of construction materials used can also adversely affect water quality.  Water Supply is Climate Dependent - Droughts or long periods of time with little or no rain can cause serious problems with your supply of water.  Storage Capacity Limits Supply - The supply of water from a rainwater collection system is not only limited by the amount of rainfall but also by the size of the collection area and your storage facilities.