Siruthuli recommends solutions for effective treatment of sewage water

A city-based NGO Siruthuli has recommended four sustainable solutions to the city corporation for effective treatment of sewage water.
The organization has been carrying out water conservation and environmental initiatives. It highlighted the outcomes of projects executed using these solutions under its ‘Nalla Thanni’ initiative.
Speaking to reporters on Wednesday, Vanitha Mohan, managing trustee of Siruthuli said, they have done lot of water conservation and water-body restoration works in the district for over two decades, and they were shocked to see sewage entering almost all the water bodies.
"As time progressed, the sewage from the city started entering water bodies. Rainwater only gets into water bodies on a minimum level because of excess of sewage present in the lakes. Since the lakes are deep, the water that is mixed with sewage enters the ground, affecting borewells. Most of the reports from samples taken from bore wells give shocking results," she said.
The organization has spent the last four to five years studying viable sewage treatment solutions, which led to the launch of the ‘Nalla Thanni’ project last year, she said, adding that the initiative focuses on treating wastewater so that it can be reused efficiently.
Sathish, Trustee of Siruthuli, emphasized that water should not be viewed as a single-use resource. He said that, with proper treatment, used-water could be recycled for various non-potable purposes including construction, agriculture, gardening, industrial processes, and road work.
Krishnaswamy, a member of Siruthuli’s steering committee and the head of its waste water treatment projects, presented four key solutions. These include the installation of Decentralised Sewage Treatment Plants (DSTPs) at locations where sewage enters the water system, and the use of phyto-remediation through constructed and floating wetlands, technologies like phyco-remediation, which uses algae, and bioremediation, which employs microbes, were also among the proposed solutions. In addition to this Siruthuli also recommended setting up small-scale Sewage Treatment Plants (STPs) with capacities of up to 2 million litres per day.
Krishnaswamy shared that the Urumandampalayam pond is already being treated using an algae-based solution called Nualgi under the phyco-remediation method, and that the results have been promising.
Constructed wetlands using Vetiver grass have been introduced in Sundapalayam and the Periapallam stream, with noticeable improvement in water quality. Trials with floating wetlands have also shown effective results in smaller areas. At the event, they also exhibited the results of water treatment made on sewage. The treated water was crystal clear and it had no foul smell.
The NGO also announced that it will begin its next sewage treatment project on Friday at the desilted Vellakinar South Solai pond in Ward 14 of the Coimbatore Corporation, using bioremediation techniques involving microbes. These initiatives are part of a long-term effort to tackle the ongoing issue of water pollution in Coimbatore.
They stressed that with Coimbatore’s population likely to cross 50 lakhs by 2041, sustainable water management practices including recycling and reuse will be critical to the city’s future.