Narayani Pollution

Twenty years ago this week Nepali Times exposed toxic effluent being discharged into the Narayani River by a paper mill which was threatening the ecology of Chitwan National Park downstream.

Twenty years ago this week Nepali Times exposed toxic effluent being discharged into the Narayani River by a paper mill which was threatening the ecology of Chitwan National Park downstream.

The Chinese-aided Bhrikuti Paper Mill in Gaidakot was set up by Nepal government in 1984 and was later privatised. It eventually shut down in 2011 after workers went on strike.

But many more factories have sprung up along the Narayani since then. Excerpts of the report published on issue #139 4-10 April 2003:

Over the years, Bhrikuti’s discharge has been analysed and tested. One toxicity analysis of samples of Narayani water by independent researchers last year showed just how serious the problem is. One indicator of pollution is Chemical Oxygen Demand (COD), and according to Nepali law, COD content in industrial discharge cannot exceed 250 mg/l. A sample of Bhrikuti’s effluent showed a whopping 979.6 mg/l. Even 1 km below the mill, the river had COD of 58.14 mg/l, whereas the international threshold for drinking water is in the 5-10 mg/l range.

Another indicator of pollution is Biological Oxygen Demand (BOD) which measures the amount of biologically usable oxygen in the water. A low BOD value implies a lot of micro-organisms present in the water (which is a healthy sign). Bhrikuti’s effluent water had a BOD count of 74 mgO2/l, and 1 km downstream it was 6.4 mg O2/l. Narayani water above the mill was measured at only 3.6 mg O2/l.

Measuring the pH value of discharge is an indicator of alkaline content, and the paper mill’s effluent was 11.5 on the pH scale, whereas this value is not supposed to exceed pH 9 in industrial discharges. Since the pH scale is logarithmic, this means that the alkalinity of Bhrikuti’s effluent was almost 1,000 times more than permissible standards. The researchers also detected high concentrations of ammonium nitrate and nitrite.

All this is poisoning wildlife like gharial, tiger, rhino and other animals, birds and plants in the national park.

From archive material of Nepali Times of the past 20 years, site search: www.nepalitimes.com

  • Most read