Domestic and Non-domestic Needs
The recommended values for domestic and non-domestic purposes are given in Table 2.1
Table 2.1
Sl. No. | Classification of towns/cities | Recommended maximum Water Supply Levels (lpcd) |
---|---|---|
1. | Towns provided with piped water supply but without sewerage system | 70 |
2. | Cities provided with piped water supply where sewerage system is existing/ contemplating | 135 |
3. | Metropolitan and Mega cities provided piped water supply where sewerage system is existing /contemplated | 150 |
Note:
- In urban areas, where water is provided through public Standposts, 40 lpcd should be considered;
- Figures exclude “Unaccounted for water (UFW)” which should be limited to 15%
- Figures include requirements of water for commercial, institutional and minor industries. However, the bulk supply to such establishments should be assessed separately with proper justification.
Institutional needs
The water requirements for institutions should be provided in addition to the provisions indicated in (a) above, where required, if they are of considerable magnitude and not covered in the provisions already made. The individual requirements would be as follows:
Sl. No. | Institutions | Litres per head per day |
---|---|---|
1. | Hospital (including laundry) (a). No. of beds exceeding 100 (b). No. of beds not exceeding 100 | 450 (per bed) 340 (per bed) |
2. | Hotels | 180 (per bed) |
3. | Hostels | 135 |
4. | Nurses’ homes and medical quarters | 135 |
5. | Boarding schools/colleges | 135 |
6. | Restaurants | 70 (per seat) |
7. | Air ports and sea ports | 70 |
8. | Junction sta5tions and intermediate stations where mail or express stoppage (both railways or bus stations) is provided | 70 |
9. | Terminal stations | 45 |
10. | Intermediate stations (excluding mail and express stops) | 45 (could be reduced to 25 where bathing facilities are not provided) |
11. | Day schools/colleges | 45 |
12. | Offices | 45 |
13. | Factories | 45 (could be reduced to 30 where no bathrooms are provided) |
14. | Cinema, concert halls and theatre | 15 |
Fire Fighting Demand
It is usual to provide for fire fighting demand as a coincident draft on the distribution system along with the normal supply to the consumers as assumed. A provision in kilometers per day based on the formula of 100vp where, p=population in thousands may be adopt for communities larger than 50,000. It is desirable that one third fire-fighting requirements form part of the service storage. The balance requirement may be distributed in several static tanks at strategic points. These static tanks may be filled from the nearby ponds, streams or canals by water tankers wherever feasible. The high rise buildings should be provided with adequate fire storage from the protected water supply distribution.
Industrial needs
While the per capita rates of supply recommended will ordinarily include the requirement of small industries (other than factories) distributed within a town, separate provisions will have to be included for meeting the demands likely to be made by specific industries within the urban areas. The forecast of this demand will be based on the nature and magnitude of each such industry and the quantity of water required per unit of production. The potential for industrial expansion should be carefully investigated, so that the availability of adequate water supply may attract such industries and add to the economic prosperity of the community. As can be seen from, the tabulation, the quantities of water used by industry vary widely. They are also affected by many factors such as cost and availability of water, waste disposal problems, management and the types of processes involved. Individual studies of the water requirement of a specific industry should, be made for each location, the values given below serving only as guidelines. In the context of reuse of water in several industries, the requirement of fresh water is getting reused considerably.
Industry | Unit of production | Water requirement in Kilometers per unit |
---|---|---|
Automobile | Vehicle | 40 |
Distillery | (Kilolitre Alcohol) | 122-170 |
Fertilizer | Tonne | 80-200 |
Leather | 100Kg (tanned) | 4 |
Paper | Tonne | 200-400 |
Special quality paper | Tonne | 400-1000 |
Straw board | Tonne | 75-100 |
Petroleum refinery | Tonne(crude) | 1-2 |
Steel | Tonne | 200-2580 |
Sugar | Tonne (cane crushed) | 1-2 |
Textile | 100Kg (goods) | 8-14 |
Pressure requirements
Piped water supplies should be designed on continues 24 hours basis to distribute water to consumers at adequate pressure at all points. Intermittent supplies are neither desirable from the public health point of view nor economical. For towns where one-storeyed buildings are common and for supply to the ground level storage tanks in multi storeyed buildings, the minimum residual pressure at ferrule point should be 7m for direct supply. Where two storeyed buildings are common, it may be 12m and where three storeyed buildings are prevalent 17m or as stipulated by locals’ byelaws. The pressure required for fire fighting would have to be boosted by the fire engines.