Though there are many inlets to the water body, only when these inlets are cleared there would a steady flow of rainwater during the monsoon. During the rest of the days, only the contaminated water from the residential areas flows into the lake.
“When the contaminated water directly gets discharged into the lake, we won’t be able to save the water body. So, before desilting the lake, it is important to eliminate this polluting factor, only after which we can maintain the lake water for domestic use. To address the problem, we have planned to set up a wetland treatment system,” said Darwin Annadurai, Environmental Scientist associated with the NGO Eco Society India.
Apart from the sewage discharge from the residential area, the lake is polluted with suspended particles and dissolved substances. These suspended particles can be separated by a sedimentation tank, he said adding the major cause of pollution is nitrate, nitrogen, and phosphorus.
“When there is a steady inflow of water with dissolved substances, the algae growth will be more compared to invasive plants. To avoid this, we are designing a wetland treatment system, which is a square tank-like structure. Through this, the contaminated water can be treated. When the water gets discharged through this tank, it will absorb the dissolved substances,” said a volunteer from the Eco Society of India.
Only after this treatment system is set up, the team wants to go ahead with the desilting work. The team has sent the design and proposal to the Tambaram Municipality and district administration a month ago but is yet to get a go-ahead, if the permission is granted, the work will be started within two months.
Speaking to DT Next, a senior official at Tambaram municipality said, “The place is under Revenue Department. Only after getting the NOC from the department concerned, the approval will be given to the NGO.”