TGPCB confirms severe pollution of Domadugu village lake by Hetero Drugs

In Nalla Cheruvu lake of Domadugu village in Sangareddy district where villagers are protesting against the pollution of the lake by Hetero Drugs manufacturing unit, the Chemical Oxygen Demand (COD) rose from 64 milligrams per litre (mg/l) in June, 2021 to 1,676 mg/l by August, 2025. Dissolved Oxygen during the same period reduced from 5.2 mg/l to 1.2 mg/l.

COD is the measure of the oxygen needed to chemically oxidise organic pollutants in water. The higher the measure, the more pollution it indicates. Dissolved oxygen measure indicates the contrary: the higher the measure, the better the health of the water.

The figures were mentioned by the Telangana Pollution Control Board (TGPCB) which issued directions to the Hetero Drugs at the beginning of the year, directing it to get its act together or face penal action. Residents of Domadugu village have been protesting for months against the pollution they alleged was being caused by the company, with the latter refusing to take responsibility.

Around September last year, the water of the lake turned pink, causing anxiety among the villagers, who had witnessed a similar phenomenon 13 years ago due to the pollutants being let into the lake water by the company.

After the latest instance, the TGPCB issued directions to the company seeking it to get the water samples analysed by IIT-Hyderabad. The study was done by an assistant professor from the institution’s Civil Engineering wing.

The IIT-H report, cited in TGPCB order, concluded that the pink coloration is a symptom of severe ecological imbalance, driven primarily by nutrient overloading, and subsequent development of “anoxic, microbially active” conditions. The physiochemical data shows elevated turbidity and significant nutrient enrichment from nitrogen and phosphorus. Under these oxygen-poor conditions, sulfate-reducing bacteria became active, generating hydrogen sulfide and providing the chemical environment necessary for proliferation of specialised pigmented microbial communities, the report read.

Task Force Committee of the Board, during its inspection, noted poor functioning of the industry’s Zero Liquid Discharge system and non-compliance with the consent conditions of the Board.

Chemical fingerprinting analysis of the water samples revealed uniformity in the chemicals found in water samples from the lake, stagnated water outside the compound wall of the unit, and rainwater storage tanks of the industry, which confirms that the effluents discharged by the industry were the cause of pollution in Nallakunta lake.

The committee also noted repeated non-compliance of consent conditions and Board directions during seven inspections over the past three years.

While not imposing any penalty on Hetero Drugs, whose founder and chairman is Rajya Sabha MP B. Parthasaradhi Reddy, the TGPCB merely asked it to furnish bank guarantee worth ₹64 lakh, in addition to the existing ₹32 lakh. It also issued directions for compliance with the conditions of Consent for Operation and Hazardous Waste Authorisation, and Board’s earlier directions, among others.