Recent Trends in Technologies in Sewerage System

As per Census 2001, 30.66 million urban households which form 35.49% of the urban households suffer inadequate access to sanitation. According to the report of the Central Pollution Control Board (2009), the estimated sewage generation from Class - I Cities and Class - II Towns is 38254.82 million litres per day (MLD) out of which only 17787.38 MLD (35%) is being treated and the remaining is disposed into the water bodies without any treatment due to which three-fourths of surface water resources are polluted. The Ministry of Urban Development conducted a rating of class I cities on sanitation related parameters in 2009-10.Out of 423 cities, only four were in the blue category scoring more than 66 points out of 100. No city achieved the distinction of being a green city i.e. a city scoring more than 90 out of 100.

According to the Constitution of India, water supply and sanitation is a State subject and the States are vested with the responsibility for planning, implementation of water supply and sanitation projects including O&M and cost recovery. The 74th amendment envisages transfer of this function to the urban local bodies. However, the Govt. of India supplements the efforts of the states in various ways – sanction of funds for the implementation of projects, technical guidance, capacity building etc. As on date, 111 sewerage schemes at a total estimated cost of Rs. 14,834.14 crores have been sanctioned under the UIG component of JNUURM. 96 sewerage schemes at an estimated cost of Rs. 2862.29 crore have been approved under UIDSSMT component of JNNURM. In recognition of the need for a special focus on sanitation, the National Urban Sanitation Policy was adopted in October 2008 with a focus on elimination of open defecation, integrated city wide sanitation, proper Operation & Maintenance of all sanitary installations etc. The initiatives under the policy include rating of cities, awareness generation and support to cities for preparation of city sanitation plans.

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. The handbook of service level benchmarks can be accessed at http://www.urbanindia.nic.in/programme/uwss/slb/slbhandbook. The 13th Finance Commission has made it mandatory for all cities having municipalities and municipal corporations to disclose their performance in terms of these benchmarks annually. The Ministry is committed to mainstreaming these benchmarks through its various schemes.

The enclosed note on sewerage and sewerage technologies has been envisaged in the above context. The Manual on Sewerage and Sewage Treatment published by the Ministry in 1993 emphasises conventional sewage treatment technologies such as Activated Sludge Process (ASP), Waste Stabilization pond (WSP), Upflow anaerobic Sludge Blanket (UASB) Reactor etc. Over the last two decades, many new technologies for sewerage and sewage treatment have emerged. These technologies which are being used in other parts of the world have not been deployed in India on a large scale. Therefore, their techno-economic viability under Indian conditions needs to be proven and will depend on prevailing local conditions, urban settings, community acceptability etc. Each of these technologies has its own merits and demerits.

Currently, most sewerage projects are bid out on Engineering Procurement and Construction (EPC) basis and have a limited role for the EPC contractor in operation and maintenance of assets. In many instances, the assets are of relatively poor quality, and are inadequately maintained. In order to ensure optimum utilization of funds deployed and proper creation and maintenance of assets, it is desirable to explore the option of Build-Own-Operate-Transfer (BOOT) contracts wherein there is a likelihood of long-term commitment of the Private Sector Partner. The different PPP models for implementation of these technologies have also been suggested in the Advisory Note.

It is hoped that this advisory will encourage the implementors in the field to innovate and explore new technologies as well as PPP models without compromising on the basic safeguards both technical and financial.