Adequate sanitation, together with good hygiene and safe water, are essential to good health and to social and economic development. Sanitation has now become our national agenda. The way in which Swatcha Bharat Abhiyan is being accepted by the Indian community, there would be a time when all the hurdles of public acceptance for underground sewerage schemes will be definitely removed. The self-sustainability of such scheme is generally challenged by the public acceptance and readiness of the users to pay the taxes for the services.
Although, the sanitary numbers of Maharashtra are fairer when compared with other states but there is always a huge scope of improvement. Things would be even better if we change our focus from the Municipal corporations to Municipal councils that are the small municipalities. The major reason behind the lacking of the underground sewerage network and treatment facility in these areas is non-availability or non-compliance of 135 LPCD water supplies which is one of the conditions for the underground sewerage network approval.
Waste water is now being carried out through the open drainages to minor and major nallas and then to some major level water body. There is always a risk of severe health hazards due to these open drainage and chances of water borne and vector borne diseases in the municipality area. This directly affects the medical and financial condition of the local residents of the municipalities. Untreated waste water from these municipalities flows and get mixed with the water bodies which are also the source of water supply for some other cities/towns. Furthermore, ecology of the ponds, lakes and reservoirs is getting badly affected. Considering all these aspects there is a strong need for implementation of the underground sewerage implementation projects.
Design of the sewer network, intermediate pumping stations, capacities & process of treatment of the proposed treatment plant is the key parameter for successful running of the sewerage scheme on ground after commissioning. Decision of the treatment processes and technologies are to be decided appropriately considering the local constrains. Futuristic approach for finalization of the demands and sanitary loading are equally important when we are concerned about the cost optimization and implementation of the plan on the ground. Considering this advanced GIS technologies along with the software able to simulate the sewerage model and recommend the strategy that can help the municipality to successfully lay the network, operate and maintain the network and the treatment plant for the design period.
Ability of the software to simulate the forecasted conditions enables the designer to try the alternatives and decide the best run possible. We can prepare the estimates from the results of the software and those results are pragmatic. As the model is based on the GIS the lengths of the conduits, depth of the structures and all other parameters can be directly exported from the model.
Though, we have modern software, technologies and expertise in terms of manpower, we need to have a precise data collected from ground. Elevation data of the area of interest, details of existing drainage arrangements and input data for sanitary loadings should be collected from the ground. We use ETS for elevation survey; tab based mapping tools for surveys and Sewer Gems for sewer modeling.
Demands are finalized as per the population projections. Population is projected using various statistical methods and trends as per historical data of the decadal populations. Demands are finalized as per population of the proposed stages and demand for floating population, Industrial, Institutional and commercial usage is worked out. Infiltration of 10 to 15% is considered as per ground water availability and final load of the system is calculated. Sewer network is designed considering the various parameters and norms as per CPHEEO manual.