Perundurai SIPCOT groundwater contamination: 37 sources in 25 villages unfit for drinking

Groundwater contamination around the SIPCOT Industrial Growth Centre at Perundurai in Erode district has returned to the spotlight after the Tamil Nadu Water Supply and Drainage (TWAD) Board found water from 37 sources across 25 villages unfit for drinking. In a letter dated March 7, 2025, the Board told the Chennimalai Block Development Officer that samples drawn from electric motor pumps, hand pumps, open wells and overhead tanks in the Mukasi Pidariyur, Vaipadi, Varapalayam and Ingur village panchayats showed excessive total dissolved solids, nitrate, iron and total hardness. Authorities were asked to install warning boards, stop the operation of electric motors at these sources and direct residents to drinking water supplied through the Combined Water Supply Scheme.

A large and varied industrial cluster

Established in 1991 across 2,700 acres, the Perundurai estate now hosts more than 250 industries, including 52 textile dyeing and processing units. Of these, 43 run individual Effluent Treatment Plants while nine are linked to a common treatment arrangement. The estate also has a tannery history: 23 units operating along the Cauvery and Kalingarayan Canal in Erode were shifted there in 2001, and 14 units were later established under a common effluent treatment arrangement. The tannery units and the common plant were closed in 2021 after pollution complaints.

Long-standing complaints

Farmers and residents have for years alleged that seepage from textile-processing units entered the Nallaa Odai and then reached the 13-acre Odaikattur tank and the nearly 400-acre Punjai Palatholuvu tank. The Perundurai SIPCOT Affected People's Welfare Association, formed in 2018, took up the issue at multiple forums. Its coordinator, S. Chinnasamy, said farmers used local waterbodies for cultivation until around 2005, when they began noticing changes in colour and a foul odour. The association alleges untreated tannery effluents were discharged into oxidation ponds, unused borewells and waterbodies, and that leakage from storage and treatment facilities contaminated groundwater. It claims TDS in groundwater crossed 15,000 mg/l in 2018 and fell to around 8,000 mg/l in 2025 after discharge was stopped. The association says contamination now extends roughly 10 km from the estate, affecting drinking water sources, livestock and agriculture.

Safe water and a new treatment plant

Residents currently receive piped safe drinking water, with groundwater used mainly for other domestic purposes. Following requests for more supply, district Collector S. Kandasamy directed TWAD officials to extend the duration of supply to affected villages. The larger question is whether the contaminated groundwater and waterbodies can be restored.

A State government order dated November 20, 2023 sanctioned a 2,000-KLD Common Seepage Water Treatment Plant based on Zero Liquid Discharge with a hardness-removal facility, initially estimated at ₹40 crore. The proposal was later modified into a Design, Build and Operate ZLD-based Common Effluent Treatment Plant with five years of operation and maintenance. A work order was issued in 2025 for ₹136.76 crore, and construction began in February 2026. The plant is meant to collect and treat contaminated seepage on the estate premises and maximise recovery and reuse, reducing the chance of polluted water entering drains and nearby waterbodies. Its success will depend on proper seepage collection, industry compliance and preventing illegal discharge or bypassing of treatment systems.

Scientific study and the road ahead

The CSIR-National Geophysical Research Institute, Hyderabad, carried out hydrogeological and geophysical investigations in 2019 to map groundwater movement and pollution-affected areas. According to the association, NGRI drilled seven large borewells and 30 smaller ones and used 14 existing open wells for sampling. The association says an interim report was submitted but not made public, and that releasing the full assessment would provide a baseline for future groundwater quality.

Commissioning the treatment plant is the immediate priority, but sustained monitoring will be essential. Industries must keep individual ETPs running and route wastewater through approved systems, while the Tamil Nadu Pollution Control Board must regularly check compliance and act against violations. The 37 identified sources should be tested periodically with results made public. The association has also suggested including 26 waterbodies around SIPCOT left out of the Athikadavu–Avinashi scheme in its second phase, arguing an alternative water source could reduce groundwater dependence and help affected waterbodies recover. Mr. Chinnasamy has further proposed that SIPCOT consider pumping groundwater from affected villages to a treatment facility for reuse in the long term.