08-16-2017, 09:16 PM
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A POLICY FOR SUSTAINABLE WASTE-WATER MANAGEMENT
Mrs Almitra H Patel, MS MIT (USA) 50 Kothnur, Bagalur Rd, Bangalore 560077 Member, Supreme Court Committee for Solid Waste Management in Class 1 Cities
Consultant, Ganga ICDP Kanpur, and Convener, INTACH Waste Network
ABSTRACT:
India needs to evolve its own set of criteria and policies for natural, low-cost, low-maintenance waste-water treatment systems that do not fail when there are daily and unscheduled power cuts, and do not incur prohibitive power bills, as conventional sewage-treatment plants do. This paper suggests a list of alternative options, arranged in order of priority. These include Waste-water minimization and Decentralised Sewage Treatment options like individual-site or neighbourhood solutions and natural waste-water treatment within storm-drains, which is by far the most desirable choice because it also provides citizens with beautiful recreational spaces at little additional cost, as at Pune. Duckweed aquaculture is an option for perennially flowing drains. Waste-water treatment in lakes via aerated floating gardens can also desilt them over time at no additional monetary or environmental cost. Seasonal rivers receiving polluted waters can have constructed wetlands or non-monsoon seasonal bunds that create a series of riverbed oxidation ponds to improve water quality. Waste-water agriculture through grass-farms, and silviculture through high-rate-transpiration plantations are described. Finally, fiscal incentives and monetary policies necessary for the success of natural waste-water systems are outlined as a guide for policy-makers.
India has begun to address the problem of cleaning up its major Rivers, one by one, and the Courts have given added impetus to this effort. The immediate response of State or city governments is usually to plan for and install conventional Sewage Treatment Plants (STPs) for all, or major, riverside cities and towns. Yet all over India, despite massive investments, conventional waste-water treatment has largely failed. The cost of leading waste-water via Under-Ground Drainage (UGD) to centralized plants is prohibitive, costing upto 80% of the total cost of waste-water treatment facilities. UGD maintenance is rarely budgeted for, very expensive, and very disruptive of other infrastructure like roads or structures constructed over the UGD. Centralised plants themselves are highly capital-intensive, energy-intensive and easily disrupted by power fluctuations.
Most such waste-water plants in India are regularly bypassing their equipment partially or entirely, because they cannot afford to pay their electricity bills or because they cannot cope with daily and unscheduled power cuts and power fluctuations which disrupt biological processes by turning aerobic ponds into anaerobic ones. In the 87 Municipalities I have visited so far during the last 8 years, in conventional Sewage Treatment Plants (STPs), the clarifier is mostly not working or not being operated because of high electricity costs or intermittent power supply, the oxidation ponds are choked with water-hyacinth (which is not harvested or composted so there may perhaps be little fresh uptake of sewage nutrients) and, where there are no grass farms, the foul-smelling almost-raw sewage is fed to sugarcane or paddy farmers downstream or released into a creek or river.