City Sanitation Plan, Uttarakhand Detailed Plan report, Muni Ki Reti 1

City Sanitation Plan, Uttarakhand
Design of effluent disposal facilities for the collection, treatment and disposal of wastes is dictated
primarily by the estimated organic loadings to be handled. In developing such estimates, it is
necessary to determine on a unit basis not only the flow or volume of waste but its strength and
composition too. With respect to flow, peak flow rates must be known in order to determine the
required hydraulic capacities of sewer, pumping stations, treatment plants and effluent disposal
facilities. Similarly, strength and composition must be known in order to determine the degree and
type of treatment required to produce effluent of acceptable quality. A study of waste volumes and
its characteristic are a preliminary necessity to the development of Design Criteria.
As a preface to a detailed discussion of flow determine, attention must be directed to the three
important components of waste water volume. Of these, the first consists of sanitary sewage, the
second industrial waste, and the third consists both, the sub surface water which enters
through manhole openings and unauthorized drain connections. The third component is termed
seepage, depending on the means of access, either infiltration or storm inflow. It is necessary to
consider the total sewage volume in terms of peak, average non peak flow in accordance with the
rate of water supply, in order to determine in normal loading to be imposed on major units of a
treatment plant, hydraulic capacity required for sewage, pumping stations & rising mains etc. Unit or
per capita sewage flow are conventionally determined from a study of a recorded flow data and
population served. Then with the basic data of present flow at hand future changes are to be
projected and suitable future design allowance are determined.
A reliable figure regarding per capita flow of sewage to the population served cannot be
arrived at from field tests only, however efforts have been made to assess the sewage flow
considering other connected factors, they indicated that the per capita sewage quantities within
India are estimated to be between 70% to 90% of the established per capita water supply
allowance. Hence for design purpose the quantity of sewage expected to be obtained from
residential areas within the Corporations, is estimated to be 80% of the established per capita water
allowance and has been adopted for design purposes. It is very desirable, for promotion of the
economy and welfare of the town, that the municipal sewerage system be capable of receiving
all liquid industrial wastes, which would otherwise create a health hazard or public nuisance.
Certain type of industrial wastage, however, will require pretreatment up to certain standard as
specified by the Indian Standard Institutions & Public Health Engineering Manual (Govt. of India) in
order to provide protection to the sewerage System. In area to be provided with separate
sanitary sewer, it is neither necessary nor desirable that hydraulic capacity be provided in the
sanitary sewer for all of the water consumed and wasted by the industries.
Detailed Plan report, Muni Ki Reti
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