According to the Indian Constitution, water supply and sanitation are state subjects, and states are responsible for the planning, implementation, and cost recovery of water supply and sanitation projects. This function will be transferred to urban local governments under the 74th amendment. The Indian government, on the other hand, supports state efforts in a variety of ways, including funding for project implementation, technical assistance, and capacity building.The Ministry has adopted service level benchmarks for the water and sanitation sector with a view to shift the focus of urban development projects from infrastructure creation to improvement of service levels.
Sewage Collection System
The practice of conventional centralized sewerage system with deep sewers and manholes in middle of roads is an inheritance from advanced countries with high water usages. Due to high capital and O&M costs and large quantity of water usage, such technologies, though technically feasible are not economically viable especially in O&M under Indian conditions. Almost all local bodies are not financially self-sustainable and look up to the State & Central Governments for financial assistance. Also, in the initial years, the emerging urban layouts are predominantly served with septic tanks and the partly treated sewage flows uncontrolled onto streets or kutcha drains, meandering aimlessly and even stagnates here and there causing many avoidable environmental hazards.Some of the alternative technologies for collection system are proposed as under-
Small Bore Sewers / Shallow Sewers / Simplified Sewerage / Twin Drains
Smaller bore shallow sewers with chambers are installed along property lines, encouraging community participation, and eventually connected to interceptor sewers and treatment, avoiding road cuts and deep manholes.
Pipe Material in Centralized Collection System
The collection system implies that sufficient liquid is available in order to achieve its targeted performance by transferring solids and liquids at the same time.The existing handbook specifies the needed pipeline slopes as well as the minimum per capita lpcd required to maintain the pipeline's requisite velocities.
EMERGING SEWAGE TREATMENT TECHNOLOGIES
Traditional sewage treatment technologies, such as the Activated Sludge Process (ASP), Waste Stabilization Pond (WSP), Up-flow Anaerobic Sludge Blanket (UASB) Reactor, and others, are routinely used in sewerage systems to treat wastewater up to secondary levels in accordance with effluent requirements.
There are a number of innovative treatment methods that have recently come into use, and they each deserve consideration in their own right, as shown below, but the challenge is the design base, which must be standardised for acceptance in government-funded programmes.
Recently, JNNURM projects have authorised the following technologies: Sequencing Batch Reactor (SBR) and Moving Bed Biofilm Reactor (MBBR)/ Fluidized Aerobic Bioreactor due to its advantages such as minimal land requirements, good effluent quality, and so on. MBR technology has been used to put up small scale plants at Bangalore and the Commonwealth Village Complex, as well as Akshardham in New Delhi. Some of the recent treatment processes involve:
1. Sequencing Batch Reactor (SBR)
2. Moving Bed Bio Reactor (MBBR) / Fluidized Aerobic Bioreactor (FAB)
3. Membrane Bio Reactor (MBR)
