Coimbatore Groundwater Crisis: Vellalore Dumpyard Contamination Exceeds Limits
Recent investigations by the Tamil Nadu Pollution Control Board (TNPCB) and a private laboratory have uncovered alarming levels of groundwater contamination in residential areas surrounding the Vellalore dumpyard in Coimbatore. The findings indicate a severe public health risk due to pollutants exceeding permissible standards.
TNPCB Report Highlights Extreme Contamination
In February, a TNPCB team collected 20 water samples from the Vellalore dumpyard and nearby borewells in residential zones. The samples included those from the leachate treatment plant inlet and outlet, as well as the leachate pit of the sanitary landfill. According to the TNPCB report, the total dissolved substance (TDS) in the groundwater was measured at 3,600 mg/l, significantly surpassing the permissible level of 500 mg/L to 2,000 mg/L maximum.
Even more concerning, the TDS levels in leachate samples reached nearly 19,000 mg/l, indicating extreme contamination from waste seepage. This high TDS concentration suggests the presence of salts, minerals, and other dissolved solids that can render water unsafe for consumption and domestic use.
Private Lab Confirms Health Hazards
Further tests conducted by the private laboratory SITARC in the first fortnight of March identified the presence of E. coli and coliform bacteria in the groundwater. These pathogens pose a severe health risk, potentially leading to water-borne diseases. The private lab report recorded a total hardness of 1300 mg/L, more than double the acceptable limit, and chloride levels at 1806 mg/L, confirming extremely high contamination.
K S Mohan, secretary of the Kurichi-Vellalore Pollution Prevention Action Committee, emphasized the dangers, stating, "The E. coli and coliform confirm sewage contamination, making the water completely unsafe for human use and the residents vulnerable to water-borne diseases like diarrhoea, typhoid, and cholera. These reports clearly prove the leachate seepage from the dumpyard, mixing of garbage waste and sewage into groundwater."
Corporation's Mitigation Efforts
In response to the crisis, Coimbatore Corporation commissioner M Sivaguru Prabakaran outlined measures to address the contamination. He explained that a scientific storage system for leachate has been established using a lagoon constructed with bentonite clay, a chemical clay material designed to prevent leachate seepage into the soil. Prabakaran asserted that this initiative would help prevent further groundwater contamination.
The lagoon spans approximately 50 cents of land on the dumpyard premises, with dimensions of 30 metres in length, 90 metres in width, and one metre in depth. It is capable of storing around 2.7 million litres of leachate water. The base of the lagoon involves soil stabilisation, prepared by laying a layer of sand, over which bentonite is placed along with protective layers before leachate is directed into the lagoon.
Despite these efforts, the contamination reports underscore ongoing challenges in managing waste disposal and protecting groundwater resources in Coimbatore. Residents continue to face health risks, highlighting the need for sustained monitoring and stricter enforcement of environmental regulations to ensure safe water access.
