Water Supply, Drainage and Sanitation

 In urban areas, where their are large sections of populations that live in informal settlements or in poor quality housing, people do not have clean water or sanitation. Municipal authorities are unable to provide water and sanitation services too all and many access these informally/illegally. The lack of the basic services results in malnutrition and poor health, loss of lives and livelihoods, and has devastating consequences on public health and environment. 

All buildings are planned taking into consideration their requirements with regard to adequate water supply, drainage and sanitation. Plumbing drawings are prepared showing piping systems that supply water and carry waste water to the sewer. Must of the residential plumbing is standardized by the local authorities. The details and brief of this specification is given in IS 1172:1993. 

But before telling something about this code, water supply or sanitation is required in all over commercial areas and buildings. Such as office, malls, airports, seaports etc. The water supply, drainage and sanitation requirement specified for railway stations, bus stations, bus terminals, seaports, airports include provisions for waiting rooms, waiting halls etc. 

Water Supply Requirements 

Residential requirements :- The requirements regarding water supply, drainage and sanitation for residence should assume that a minimum water supply of 135 liters per head per day is assured, together with a full flushing system.   

Other buildings :- The requirements for water supply in other buildings are given in the following table  

For railway stations, bus stations, sea ports etc. ranges from 45 - 70 liters per capita, where bathing facilities are provided. And where its not provided, it requires less than that. For any intermediate stations, junction stations or for terminal stations water capacity is required day to day, that much. And where airports (any domestic or residential airports) it requires 70 liters per capita both for bathing facilities and drinking water facilities. 

Drainage 

Adequate arrangements shall be made for satisfactory drainage for all sewage and waste water. The drainage shall be so designed as to cause no stagnation at maximum discharge rate for which the different units are designed. The different types and systems used for drainage purposes are : 

1. A two pipe system should be used in which one pipe collects the foul soil and lavatory wastes, whereas the second pipe collects the unfoul water from the kitchen, bathrooms, house washings etc. 
2. Sewage pipes should be connected to sewers. All soil pipes should be carried direct to the man holes without gully traps. This is because waste pipes are connected through the trapped gully. 
3. All pipes should be laid in straight lines as far as possible in both the vertical and horizontal planes. 
4. No bends and junctions are to be permitted in sewers except at manholes and inspection chambers. 
5. All junctions of pipes should be oblique and the contained angle should be not more than 45 degrees. 
6. If it is necessary to lay a drain under a building, pipes should be cast iron/RCC and drains should be laid in a straight line at uniform gradient. 
7. Manholes should be provided outside the building. As well as drains should be provided under a staircase area or at the passage side. 
8. All vertical soil waste ventilating and anti-siphonage pipes should be covered on the top with a copper or heavily galvanized iron wire dome. 
9. Waste pipes - Every pipe in a building for carrying waste or overflow from water bath, wash basin or sink to a drain should be of 32-50 mm diameter. 
10. Ventilating pipes - This ventilating pipe or shaft should be carried to a height of at least 600mm above the water covering of the roof, 1200mm above the parapet wall or in case of flat roof. 
11. Anti siphonage pipes - The minimum diameter for these pipes, for soil pipe should be 50 mm and for waste pipes 40 mm. 
12. Manhole and inspection chamber - At every change of alignment, gradient or diameter of a drain, there should be a manhole or inspection chamber. 
13. Inspection chambers of suitable size, min 600 X 450 mm should be provided at the junction of pipes, change in direction and at intervals for maintenance purpose. 
14. Rain water pipes - A rain water pipe, carrying rain water should be discharged through a channel to the surface drain. 
15. Roof gutters - The gutter should be semi-circular in section, with a width at top twice the diameter of the downtake pipe. The gutter should be fixed 25 mm below the edge of the roof. 

Design of Drainage System 

Drainage system should be designed with reference to the following data: 

1. Site plan - A plan to scale 1:400 or 1:800 with reduced levels of ground, lowest floor level, position and diameter of public drain. Water supply main on the road and invert level of public drain or sewer. 
2. Detailed drawings - Plans and sections of the proposed building showing the positions and types of all sanitary fittings with positions and types of rain water down pipes. 
3. Use - Use for which the building is intended, periods of occupation and peak hour discharge. 
4. Bye-laws - The requirement of local bye-laws is regard to the drainage and sewerage. 
5. Sub-soil conditions - These conditions govern the choice of design of the sewer or drain and method of excavation. 

Sanitation 

Sanitation refers to public health conditions related to clean drinking water and treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as with hand washing with soaps. Sanitation system aims to protect human health by providing a clean environment that will stop the transmission of diseases. There are many other diseases which are easily transmitted in communities that have low level of sanitation, such as ascariasis, cholera, hepatitis, polio, trachoma etc. 

The Human Rights to Water and Sanitation (HRWS) was recognized by the United Nations General Assembly (UNGA) in 2010. Sanitation is a global development priority and subject of Sustainable Development Goal. The estimate in 2017 by JMP states that 4.5 billion people currently do not have safely managed sanitation. Lack of access of sanitation has an impact not only on public health but also on human dignity and personal safety.