1 / 42

TECHNICAL OPTIONS

TECHNICAL OPTIONS. For SUSTAINABLE WATER SUPPLY SCHEMES. Drinking water for Human Needs.

belle
Download Presentation

TECHNICAL OPTIONS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. TECHNICAL OPTIONS For SUSTAINABLE WATER SUPPLY SCHEMES

  2. Drinking water for Human Needs. • Drinking water has always been the lifeline of sustainable human residence or inhabitations. Ever since the presence of man and animal on earth, the development of habitations has taken place along or near the water bodies like rivers, lakes, ponds and the like. There are evidences of the human populations having shifted away to alternative settlements in case of the drying up of the near by water bodies/sources for one reason or the other. It is therefore important to see that sustainable drinking water options are available to the communities for sustenance of life, and more so far sustainable development.

  3. How much water do we need ? • The need of water has varied with the development and it may be reasonable to say that small communities like those in villages and suburban areas would need less water than those in large community areas like the urban and even bigger areas of metros, mega cities.

  4. The minimum needsDrinking water needs – without Sewerage • The minimum needs of drinking water for rural areas with only spot sources like hands pumps is considered to be limited to 40 liters per capita per day (40 lpcd). • Rural areas served with pipeline are estimated to use at least 70 litres per capita per day. An average 15% wastage is also added to the above to work out the gross requirement of water.

  5. The minimum needs (Contd.)With provision for Sewerage • In the urban areas with sewerage or contemplated sewerage the above figures would escalate to 135 lpcd or 150 lpcd plus 15% wastage. The detailed standards regarding the volumes of supply could be seen in the manual on water supply issued by the Govt of India.

  6. The various options for water supplyHand pumps and Dug wells  Hand pumps (India mark-II, fitted over deep bore tubewells)  Sanitary wells  Sanitary wells fitted with Hand pumps (India mark-II)

  7. The various options for water supply (Contd.)Piped water supply options  Piped water supply with Public stand posts only  Piped water supply with public stand posts & Private connections.  Piped water supply with Private connections and limited public stand post facility and Hand pumps for public use.

  8. DETAILED DESCRIPTIONOF VARIOUS OPTIONS

  9. Deep Bore India Mark-II Hand PumpsSafe drinking water • Ground water drawn from the second and deeper strata would generally need no treatment except for periodical disinfection of the bore-well. This is done by pouring a bleaching powder solution and then withdrawing and wasting the discharge after the minimum contact period. It is generally adequate to pour the solution late in the evening after usage and then shut down until next morning. Withdrawing and Wasting adequate water next morning visibly until no smell is felt, and as soon as usual clear water is obtained, it would complete the process of disinfection.

  10. Deep Bore well India Mark-II Hand PumpsInstallation and Maintenance • Detailed instructions for installation, maintenance and disinfection may be seen in the Manual on water supply O & M, recently published by Govt. of India.

  11. Sanitary wellsThe Only option in particular Hydro-geographical-conditions • Sanitary wells are required in some areas where small bores would not be feasible for the reason of rocky terrain and relatively small yields that would require larger diameters for infiltration of the required volumes of water. Sanitary wells would generally take water from the second and deeper strata, and should be covered at top, with raised platforms to prevent any contamination from finding way into the wells. • Water drawn from sanitary wells is generally free from impurities and would not require any treatment. But periodical disinfection of the sanitary wells would be necessary.

  12. Sanitary wells fitted with Hand-pumpsfor convenient drawl of water • Sanitary wells fitted with Hand-pumps are same as described above but with RCC rooftop at platform level, to facilitate fixing of hand-pump pedestal, with riser pipe of galvanized iron (32mm dia) in case of India Mark II hand-pump with its piston - cylinder submerged in well water.

  13. Deep Bore India Mark-II Hand PumpsEasy to install and maintainSafe Drinking water • Deep-bore India mark-II Hand-pumps are easy to install, operate and maintain in rural areas. The maintenance of these hand-pumps would generally require only periodical cleaning and greasing. This can be done by village community itself with routine training. • Deep-bore hand-pumps are generally installed to draw water from the second and deeper strata where ground water is safe and free from any surface contamination.

  14. Sanitary wells fitted with Hand-pumpsInspection and maintenance of well • An inspection-cum-manhole cover is given in the RCC slab top in this case. The sanitary well fitted with hand-pumps have the advantage of meeting the need in two ways-adequacy of a sanitary well and the facility of pumping by hand.

  15. Piped water supplyDrinking and Sanitation needs • Piped water supply Schemes have the advantage of giving water for domestic use and storage at required levels for every house hold use including that of sanitation and flushing. But the piped water supply schemes would involve more capital cost and maintenance.

  16. Piped water supplyDistribution Network and adequate pressures • Distribution network for piped water supply schemes is designed to carry adequate water for the design population so as to give a minimum terminal pressure at the farthest distribution ends. Contd.

  17. Piped water supply • The minimum terminal pressures required for different schemes are as follows: i. Rural Schemes- 7 m ii. Urban Schemes with double storey houses- 12 m iii. Urban schemes with more than two stories- 17 m

  18. Storage in piped water supply schemes 1) Overhead Tanks on columns 2) Over head reservoirs over Hill tops 3) Ground Water Reservoirs/Clear Water Reservoirs. Storage in piped water supply schemes may be as follows:

  19. Sources of water The source of water in piped water supply schemes may be: 1. Ground water a) Tubewells 2. Surface water a) River water b) Canal water 3. Impounded water a) Lakes b) Impounded reservoirs

  20. Water Treatment A. Ground Water • Ground water would generally need no treatment except for the disinfection usually by chlorination. B. Surface water • Surface water would need elaborate treatment depending on the quality of raw water. This could involve any or all of the following: (i) Pre-Chlorination (ii) Flocculation and sedimentation, in appropriately designed Flocculation and settling tanks. (iii) Filtration a. Slow sand filtration b. Rapid gravity filtration (iv) Post Chlorination

  21. Mini Water Supply Schemes Rural Areas • Some Water Supply Schemes implemented in the Swajal Project in Uttar Pradesh, were designed to contain only small dia deep bore wells like those done for hand pumps and fitted with small submersible pumps. This type of small dia bore-wells are economical to construct and maintain. Besides the communities find it easy to share responsibility to construct and maintain such small works. The storage reservoirs in such schemes are also correspondingly small and could be constructed with much more ease, in view of the design and land requirements for such small overhead tanks. In some cases these were reduced to tank type stand posts.

  22. Mini Water Supply Schemes (contd.) • There could be one or more small bore tubewells fitted with submersible pumps to cater the total requirement of a village depending on the total population, number of families and the number of families opting for the facility of mini water supply scheme.

  23. Preparation of DPRsUrban Water Supply Schemes under UIDSSMT The usual contents of a DPR • Salient Features • Report • Financial Statement • Economics • Technical Statements • Estimates of Works • Drawings

  24. Water Supply DPRs (Contd.) • DPRs would also preferably contain: • Unit Estimates of standardized work units. • Schedule of Rates • Annexures of reference material (If any) • Type Designs and Drawings.

  25. Water Supply DPRsDistribution Network Designs • Well designed distribution networks showing all existing lines and proposed pipelines will be essentially required for DPRs

  26. Water Supply DPRsTechnical Statement • Projected population for design period of 30 years with middle stage population (that after 15 years) • Beginning year to be taken as the year of likely commissioning of scheme say after 2-3 years from the present year 2006.

  27. Water Supply DPRsTechnical Statement-Water Source • Water demand for the design period, middle stage and in the beginning to be assessed and checked for adequacy of source. • Adequacy of source provisions to be ensured and discussed in Technical Statement and Report.

  28. Water Supply DPRsEconomics • Expenses on staff, electricity, chemicals and repairs to be given in the Economics. • Income from tariff and water charges. • Profit and/or Loss account will form main stay of the scheme.

  29. APPROPRIATE OPTIONSFORTOTAL SANITATION

  30. Meaning & Scope of Works • Development, re-organization and up-gradation of various options for household, and public sanitation has become necessary in view of the growing population pressures and consequent environmental problems, involving the social and Technical ills arising out of the continuing open defecation in rural areas.

  31. Meaning & Scope of Works • It may be assumed here that the problem of in-sanitary/conservancy toilets is negligible, and there are either some kinds of sanitary toilets present or the same have yet to come in some places. It has been observed that once the trend and technology of sanitary toilets has reached the common man in the villages the problem of in-sanitary toilets will no more exist because of the reason that the sanitary toilets devised are much more convenient to use and the cost factor is also quite manageable.

  32. Various Options for Sanitary Latrines 1. Two pit Sanitary Latrines. 2. Latrines with Single pit partitioned in two parts, alternating use. 3. Latrines with Septic tank and soak pit 4. Sewer lines with treatment units 5. Small dia sewer lines with appropriate treatment and disposal units. 6. Same as 4 & 5 above but with sewage utilization units.

  33. Applicability of Different Options at Different Places Plain areas • Plain areas with modest slopes are ideally suitable for almost all kinds of sewerage & sewage treatment works, where the population load and housing pattern would create substantial waste water load on sewers, thereby allowing the proper flow of sewage with self cleansing velocities or near self cleansing velocities. The sewers should also be laid at appropriate slopes at least to achieve self cleansing velocities during the half/full flow with flushing waters.

  34. Applicability of Different Options at Different Places • But in rural areas or such areas where the density of population is not adequate to cause sufficient flow and the system would also cause unnecessary burden of capital and maintenance costs. it would be best to use the on-site-sanitation methods and devices. Plain areas

  35. Applicability of Different Options at Different Places • Drainage is not much of the problem in hill areas. Similarly if sewers are laid in hill areas, they do not pose any problems of flow but it would generally be difficult to do excavation in rocky areas and also to find sufficient plain space for treatment works. Hill Areas

  36. Applicability of Different Options at Different Places Hill Areas • As such the sewers are laid only where this kind of sanitary works are required in view of the importance of the place. In other areas where population loads are not significant or adequate like in rural parts on site sanitation works like the leach pit latrines or latrines with septic tanks may be constructed and maintained economically.

  37. Applicability of Different Options at Different Places Hill Areas • Leach pit latrines/septic tanks would also be required to be constructed with due care to see that ground water streams which could generally be encountered in hilly terrain are not contaminated. It would also be necessary to take care of any faults, cracks or creeks in the ground terrain across the sanitary works to properly check percolation of fowl leacheates through them into water streams.

  38. Plain Areas with High Subsoil Water • Areas with high subsoil water would require special measures to be taken to save the sub-soil water from being contaminated by leach pits or septic tank effluents. Where the subsoil water could rise within 2 metres of the lowest part of the leach pit, the leach pits are sealed with impervious clayey or such other material at bottom and enveloped all around vertically with adequate thickness of filter media like sand. This would save the subsoil water from being contaminated by leacheates.

  39. On site SanitationMethods and Devices • The on-site sanitation mainly devises the waste matter to be passed into an underground dry/wet, pit/ chamber from where the liquid content is either absorbed into the surrounding ground or made to overflow into a soak pit. The former is the example of honeycombed pit type lined leach pit latrines and the latter is the example of septic tanks, with accompanying soak pits.

  40. Different types of Sanitary pit Latrines • Two pit sanitary latrines. • Single pit latrines. • Combined two pit latrine with central divide wall.

  41. Septic Tanks. • Domestic type of septic tanks with soak pit. • Community type septic tanks with arrangement for proper disposal of effluent. • Industrial type of septic tank with arrangement for proper disposal of effluent.

  42. Detailed Designs and Standards • Details of various on site sanitation devices , construction methods and various standards relating to size, and other requirements are given in chapter 21 of the manual on sewerage and sewage Treatment works published by the Government of India. Some important abstracts may be seen in the Annexure A.

More Related