The Himachal Pradesh State Pollution Control Board (HPSPCB) has confirmed that the discharge of untreated effluent and sewage into the Ratti rivulet in Mandi district caused a fish mortality incident on June 12. Laboratory analysis of water samples collected on June 12 and 13 revealed alarming pollution levels, leading to a sharp decline in water quality and depletion of dissolved oxygen, making the water body unsuitable for aquatic life.
Pollution indicators show severe contamination
According to Vinay Kumar, Regional Officer of HPSPCB, Mandi, the test results highlighted stark contrasts between upstream and downstream water quality. Downstream samples recorded significantly higher biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and coliform bacteria. On June 12, the downstream sample showed a BOD level of 70 mg/l and coliform counts exceeding 1,600 MPN per 100 ml. A sample from a discharge chamber connected to the industrial area recorded an extremely acidic pH of 3.82, TSS of 164 mg/l, and an exceptionally high COD of 4,400 mg/l.
Legal action and corrective measures
The board issued show-cause notices under the Water (Prevention and Control of Pollution) Act, 1974, and the Environment (Protection) Act, 1986, and shared findings with the General Manager of the District Industries Centre (DIC), Mandi. In response, the DIC informed HPSPCB that immediate corrective measures were undertaken, including repairing the soak pit, removing accumulated sludge, cleaning chambers, and preventing further discharge of untreated wastewater. Long-term solutions such as upgrading infrastructure into a full-fledged Sewage Treatment Plant (STP) or relocating the facility are being explored.
Follow-up inspection shows improvement
A follow-up inspection on June 19 found no active discharge entering the Ratti rivulet from the identified source. Fresh water samples were collected to assess current water quality. The board has directed authorities to ensure strict compliance with pollution control norms and stated that regular inspections and monitoring will continue to prevent recurrence.
