SHILLONG: The Meghalaya State Pollution Control Board (MSPCB) has found that organic and bacteria were the main pollutants in the Umkhrah and Umshyrpi rivers mainly due to direct discharge of waste water in an untreated form from the residential and commercial centres.
In its annual report 2016-2017, which was tabled in the state Assembly on Friday, the Board pointed out that the amount of waste received by the two rivers was much beyond their assimilative capacity leading to deterioration of the water quality to the extent it cannot be put to any beneficial use.
The water quality of Ward’s Lake meets the criteria for propagation of wildlife and fisheries. The quality of other water bodies was relatively good and can still be used for various beneficial purposes although it was not recommended for drinking unless treated and disinfected by an organised water supply system.
Further, the dissolved oxygen was found to be very low in Umkhrah and Umshyrpi rivers with the minimum value ‘nil’ recorded in Umshyrpi river (Law college) and Umkhrah river (Demthring, near Slaughter house and Mawpdang) during the dry winter months of February and March, whereas its concentration in other rivers was always above 4mg/l, which is the minimum oxygen requirement for propagation of wildlife, fisheries etc.
As for the water quality of rivers in West Khasi Hills, the MSPCB cited the Nanbah river located in the centre of the district headquarter, which was also subjected to pollution arising out of direct disposal of solid and liquid waste from residential and commercial areas, automobile workshops and servicing centres etc and agricultural runoff. However, the water of this river can be used for propagation of wildlife and fisheries and irrigation purposes.
Pointing to the quality of water in rivers of Ri-Bhoi distirct, the Board informed that the Umiam Lake received the waste generated in Shillong city through two rivers viz Umkhrah and Umshyrpi whereas the Umtrew is subjected to pollution originating from the residential, commercial and industrial areas.
The water of Umiam Lake and Umtrew River can be used for propagation of wildlife and fisheries and irrigation purposes.
In Jaintia Hills, water of four rivers have low pH levels and cannot be used for any beneficial purposes. The pH in Myntdu river at Leshka, Lunar river at Myndihati, Kyrhukhla river at Lad-Rymbai and Lukha at Sunapur was observed to be very low with the minimum value of 2.2 recorded in Lunar river during the dry month of April.
Low pH indicates that water is acidic in nature which is mainly due to acid effluent from coal mines located in the catchment and in the upstream side. The dissolved oxygen in all monitored rivers was always above 4 mg/l which is the minimum requirement for propagation of wildlife and fisheries.
Due to low pH, the water of Myntdu, Lukha , Lunar and Kyrhukhla rivers cannot be put to any beneficial use.
As for Garo Hills, the water quality of all monitored water bodies in the region was relatively good and can still be used for various beneficial purposes although it was not recommended for drinking unless treated and disinfected by an organised water supply system.
