Water management involves various human activities like irrigation, agricultural / industrial development, use of water resources for hydroelectric generation etc. For management of water quality of a water body one has to define the water quality requirements or water quality objectives for that water body. The main uses of water are public water supply, outdoor bathing & recreation, fisheries, wildlife propagation, irrigation and agriculture uses, cooling in power plants, navigation, etc.
Increase of urbanisation and industrialisation is one of the important factors causing pollution of water resources. Therefore determining the quality of water is essential to meet a given purpose and to find practical methods for achieving the quality has become essential part of water quality assessment.
Water quality monitoring:
The water quality monitoring is a must for rational development and management of water resources. It has a direct relation with chemistry, biology, statistics and also economics.
During the 1st phase of implementation of Water Act, 1974 the CPCB has defined the wholesomeness in terms of water quality requirement for protection of human uses and accordingly, it has set water quality objectives for different water bodies. If a water body or its part is being used for more than one use, then the use which demands highest quality of water was termed as “Designated Best Use” (DBU) and accordingly the water body or its parts are designated. All the major riverine systems of the country were classified in 5 categories on the basis of DBU concept.
Water Quality Monitoring Objectives:
The water quality monitoring is performed with the following main objectives. To ensure that the water quality is being maintained or restored at desired level, it is important that the Pollution Control Boards regularly monitor the water quality.
- For rational planning of pollution control strategies and their prioritization.
- To assess nature and extent of pollution control needed in different water bodies or their part.
- To evaluate effectiveness of pollution control measures already in existence.
- To evaluate water quality trend over a period of time.
- To assess assimilative capacity of a water body there by reducing cost on pollution control measures.
- To understand the environmental fate of different pollutants.
- To assess the fitness of water for different uses.