SHILLONG, Aug 27: The Meghalaya State Pollution Control Board (MSPCB) has established a network of water quality monitoring stations in the state.
According to the latest data available with the MSPCB, the present network comprises of 54 stations in the state under the National Water Monitoring Programme (NWMP) and the monitoring network covers 20 rivers, four lakes and seven spring wells.
Out of the 54 stations, few water bodies that have been identified as polluted stretch in the state in respect to the BOD level by the Central Pollution Control Board (CPCB) include Umkhrah and Umshyrpi rivers in East Khasi Hills, Kyrhukhla river and Lunar river (tributary of Lukha river) at Myndihati, East Jaintia Hills, Umtrew Byrnihat rivers, Ri-Bhoi district, Myntdu (Jowai) West Jaintia Hills and Nanbah (Nongstoin) West Khasi Hills.
As per the MSPCB report, the respective Deputy Commissioners have been informed about the status of the water bodies and requested to take necessary action and steps to formulate action plans to control the pollution source.
It was informed that the DCs have taken it up with line departments and also issued prohibitory orders against dumping of solid waste and liquid waste in streams and rivers.
Seventeen sampling stations were located in East Khasi Hills.
In all the monitored locations the pH (potential of hydrogen) level was observed to be in the normal range of 6.5 to 8.5.
“The dissolved oxygen level was found to be very low in some sampling location of Umkhrah and Umshyrpi rivers with the minimum value of 1.4 mg/L recorded at Umshyrpi River (Law College) and 0.8 mg/L at Umkhrah river at Mawlai abattoir, whereas its concentration in other rivers was always above 4 mg/L, which was the minimum oxygen requirement for propagation of wildlife fisheries,” the report said.
The monitoring results indicated that organic and bacteria were the main pollutants in the water bodies.
This was mainly due to direct discharge of waste water in an untreated form from the residential and commercial centres, it said.
The amount of waste received by two rivers Umkhrah and Umshyrpi rivers was much beyond their assimilative capacity, and thus the water quality had deteriorated to the extent that the water of these two rivers could not be put to any beneficial uses.
The water quality of Wards’ Lake meets the criteria for propagation of wildlife and fisheries, the pollution control board’s report said, adding that the water quality of other water bodies was satisfactory.
In the sampling stations in West Khasi Hills, Ri-Bhoi as well as Garo Hills districts, the pH level in monitored water bodies was in the normal range.
In Jaintia Hills, however, the pH level in Myntdu River at Leshka (Lunar river) in Lad-Rymbai was found to be very low.
The report said that the low pH indicates that water was acidic in nature which was mainly due to acid effluent from coal mines located on the catchment and in the upstream side the dissolved oxygen in all monitored rivers were always above 4 mg/L — the minimum oxygen requirement for propagation of wildlife fisheries.
