SHILLONG, July 1: Encroachment and pollution are dealing a double blow to a few of the once-pristine rivers in Meghalaya.
Verbal assurances and symbolic actions have done little to rejuvenate these rivers.
The Meghalaya State Pollution Control Board (MSPCB) has often warned people about the acidic level of the rivers and how they are becoming too toxic for the survival of aquatic lifeforms. But little seems to have been done beyond period tests conducted to assess the water quality.
The MSPCB has set up 54 water quality monitoring stations across the state under the National Water Monitoring Programme (NWMP). The monitoring network covers 20 rivers, four lakes, and seven springs or wells.
MSPCB officials said the Central Pollution Control Board identified some stretches of several rivers in the state as polluted.
These rivers include the Umkhrah and Umshyrpi (East Khasi Hills), Kyrhukhla, Lunar (tributaries of Lukha) at Myndihati, East Jaintia Hills, Umtrew Byrnihat (Ri-Bhoi), Myntdu (Jowai) in West Jaintia Hills, and Nanbah (Nongstoin) in West Khasi Hills district.
The state board informed the respective deputy commissioners of the districts regarding the status of the water bodies with a request to take necessary steps to formulate an action plan to check the sources of pollution.
The DCs took up the matter with the line departments. Prohibitory orders against the dumping of solid and liquid waste in the rivers and streams were subsequently issued.
According to an MSPCB report, the pH level (a measure of how acidic/basic water is) was observed to be in the normal range of 6.5 to 8.5 at all the monitored locations in East Khasi Hills.
The dissolved oxygen was found to be very low in the Umkhrah and Umshyrpi rivers with a minimum value of 0.5 mg/litre recorded near the Law College in Umshyrpi and at Mawlaw Abattoir in Umkhrah during February and March.
The concentration in the other rivers has always been above 4 mg/litre, the minimum oxygen required for the survival of fish, the report said.
The monitoring results indicated that organic matter and bacteria were the main pollutants in the water bodies. This was mainly due to the direct discharge of untreated wastewater from the residential and commercial centres.
According to the report, the volume of waste received by the Umkhrah and Umshyrpi rivers was much above their assimilative capacity, leading to the deterioration in the water quality.
In Ri-Bhoi, the bio-chemical oxygen demand was observed to be above 3mg/litre in Umiam Lake and Umtrew river at Byrnihat. The total coliform count in these water bodies was also observed to be high.
The well-known Umiam Lake received waste that was generated in Shillong through the two rivers viz. Umkhrah and Umshyrpi rivers whereas the Umtrew river was 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. The water quality of other water bodies was relatively good and can still be put for various beneficial purposes although it was not recommended to use directly for drinking purposes unless treated and disinfected by an organised water supply system.
