Water Quality Monitoring of the Rivers
A river is polluted to a varying degree, depending upon the amount of discharge of wastes, sewage, and industrial effluents, in the catchment area. The quantum and quality of water received from tributaries and degree of self-purification are also factors for variation in the degree of pollution. To monitor the quality of water systems regularly the 'Central Pollution Control Board' (CPCB) has initiated two programmes, 'Global Environmental Monitoring Systems' (GEMS) and 'Monitoring of Indian National Aquatic Resources' (MINARS) in our State. The objective of the programmes is to strengthen the existing system of water monitoring and improve the validity and compatibility of water quality data. Under GEMS programme five surface water stations and four ground water stations in the Godavari and Krishna basin have been identified. Under MINARS programme 19 monitoring stations have been established on rivers Godavari, Krishna, Pennar and their tributaries.
Analysis of data collected by APPCB shows the following results:* Presence of TDS is observed in the entire Godavari and Krishna river belts.
* High Electrical conductivity of 740 us/cm is observed upstream of Godavari
at Mancherial and about 512 us/cm is observed at Vijayawada in Krishna
river.
* High values of turbidity indicate heavy soil erosion in the catchment areas. The World Health Organisation guidelines for potable waters in terms of turbidity is five NTU as permissible and 25 NTU as excessive. In all the rivers in AP at almost all the monitoring
stations, the turbidity value exceeds permissible limits. During rainy season it exceeds the excessive limits. The values are within the satisfactory limits in other seasons. * The pH range is 6.5 to 8.5 for all classes of water and 6.0 to 9.0 for 'C' class water as per Water Quality Criteria Standards. The observation ranges from 7.2 to 8.5 along Godavari and Krishna belts. Hence the water is slightly alkaline in nature. Alkalinity values are higher upstream of the Godavari river.
* Osmotic pressure in all monitoring stations of Godavari and Krishna rivers is satisfactory.
