Access to quality drinking water and safe disposal of sewage have become everyday problems, especially in the city’s peripheral areas.
Taking matters into their own hands, residents of several large apartment complexes have set up recycling and treatment plants to tide over the crises.
But even as the demand for water and waste-water treatment plants rises, such systems have their share of problems.
Environmentalists say, over the past five years, the cost of such systems, on the domestic front, has decreased. But, operation and maintenance are still a problem for many.
While it is mandatory for large apartment complexes in suburbs to install sewage treatment facilities, flat owners’ associations are losing sleep trying to find a maintenance contractor.
Residents of DABC Mithilam, Nolambur, for instance, have faced health hazards due to the continuous failure of their sewage treatment facility and spent exorbitant sums to remove sewage through tankers.
D. Naveenson of W&WW Technologies, a company that offers services to maintain sewage treatment units, says, “A dedicated team and water experts are essential to maintain such facilities. We have restarted the plant at DABC Mithilam and operated it for the past few months, enabling residents to reuse waste water and save money. On an average, 40 sewage loads used to be removed from the apartment complex, now it has been reduced to four tankers, that too due to flaws in design.”
Manufacturers of water and waste-water treatment plants say there has been a 30 per cent increase in awareness of recycling facilities over the past five years.
R. Kcannan, chief executive officer, MORF India, says several apartment complexes on East Coast Road and Rajiv Gandhi Salai, and in Maduravoyal, have turned to waste-water recycling to water garden plants, thus saving fresh water.
The treatment capacity of such units ranges from 20,000 litres a day to one million litres a day. With indigenous manufacturers of the components on the rise, costs have also dipped by 20 per cent.
Similarly, demand for water purification systems too goes up by 40 per cent, every year, bringing down the price range between Rs. 10,000 and Rs. 17,500. However, residents also point to problems in water purifiers. However, Mr. Kcannan says reject water can be collected and used for washing and gardening.
Environmentalists demand the government step in to review the operation of sewage treatment plants and water purification systems, on the lines of rainwater harvesting systems.
According to N.K. Kuttiappan, an environmental consultant, few complexes have operational water and waste-water treatment facilities. This is due to the lack of certified sewage treatment plant operators, he says.
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OPTIMUM UTILISATION
Every drop of waste water can be reused with the right kind of processing
> Waste water from apartments gets accumulated in the collection (equalisation) tank
> Collected waste water is pumped in to aeration tank for the first process in sludge removal and then passed on to the second process for removing excess sludge in the clarifier tank
> Aeration tank (together with the settling/clarifier tank that follows) is at the heart of sewage treatment system. Bulk of the treatment happens here as microbes/bacteria are employed
> The water is then sent through two filters called the pressure sand filter (PSF) and activated carbon filter (ACF)
> Once, water is treated with the filters, it is pumped into the tank, to be used in the toilet or for gardening
> Outflow of excess sludge from the clarifier tank is processed as manure for gardening
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> For every litre of waste water treated, 25% can be reused in the toilet and the remaining 75% in the garden
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KEEP IN MIND
> Keep air-mixing on, in the plant, at all times
> Ensure air flow/mixing is uniform over the entire floor of the tank. Adjust placement of diffusers and air-flow rate as needed
> Keep equalisation tank nearly empty before expected peak load hours (else, it will overflow)
> Check and clean clogged diffusers at regular intervals
> Manually evacuate settled muck/sediments, at least once a year
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