ASSESSMENT OF GROUNDWATER QUALITY FOR IRRIGATION

Abstract

Groundwater is frequently used for drinking, irrigation and industrial supplies. The quality of ground-, water depends on the nature of recharge water and sub-surface geochemical processes such as leaching, precipitation and hydrolysis. There are factors, namely quantity and quality of the water which decide its use with or without treatment. For any project concerning water, it is therefore, necessary to assess its quality. Recently, under the Indo-US Collaboration, the U.S. Government has undertaken a project to develop Heritage Area of Agra and National Park in the vicinity .of Taj Mahal. It is a mul.tifacet project. One among these facetes is the exploration of groundwater and its quality assessment for irrigation and human consumption. Keeping this in view water quality of the proposed park site (approximately 2.5 x 2.5 km.) has been estimated to evaluate its suitability for irrigation. Water samples from sixteen different sources which include open wells, tubewells, hand pumps and India Mark-II pumps were collected in Oct., Nov. and Dec., 1990. The physical, chemical and bacteriological qualities were estimated. The results obtained were analysed and compared with standards for irrigation. Soil samples at different depths from a bore hole in the vicinity of a sampling site were collected and analysed to obtain (v) an idea about thc properLtes of surface and subsurface soil. The surface soil samples were analysed for judging the fertility of soil and subsurface analysed to study soil profile. The results indicate that the depends on the location of the sampling with reference to the river bed, depth station and human activities in properties were quality of water site particularly of the sampling sampling the vicinity of the location. The suitability of water for irrigation use assessed by parameters like total dissolved solids, salinity potential salinity, sodium adsorption ratio and electrical conductance reveal that the water from two stations can he universally used for all types of crops and soil. A few of them showed a limited suitability while the rest were unsuitable by one or the other criterion. The surface soil has been found to be free from trace elements toxicity hazard. It is rich in iron and silicon with sufficient cation exchange capacity, deficient in phosphorous calcium, soluble magnesium salts, manganese and copper etc. The metal profile of the soil does not indicate significant metal pollution.