Welcome to CGWB

Water Quality Analysis

Objectives :
	Evaluate composition of water for quality assessment
	Study GW relationship with natural/artificial events and processes
	Study temporal variations in Ground Water quality
	Devise measures against pollution of ground water

Activities :
	Collection of water samples under various programmes
	Water sample analysis - Inorganic, Organic & Hydrocarbon
	On the spot analysis in the fields
	Interpretation of water quality data
	Preparation of hydro-chemical maps/reports
	Ground Water pollution and evaluation studies
	R & D activities

Achievements :
	Ground water quality is being monitored by analysing water samples from statewise distributed Hydrograph station.
	Ground water in Northern district is less mineralised with the specific conductance values ranging from 100-600 mmho/cm at 250C and Cl values less than 200 mg/l.
	In hard rock terrain of Bankura, Birbhum & Purulia district, it is similarly less mineralised and specific conductance values ranging from 150-1000 mmho/cm at 250C and Cl value varies from 20-150 mg/l.
	In South 24 Parganas, Medinipur (E&W) and Haora districts specific conductance of ground water from deeper aquifers ranges between 1000-2000 mmho/cm at 250C and Cl value varies 50-300 mg/l.
	The important chemical types of water in the state are ca-Mg-HCO3 type for low mineralised water, Na-CO3 type in South 24 Parganas district and Ca-Mg-Cl type in Kolkata and some isolated patches.
	In the coastal tract of Medinipur, South 24 Parganas and Haora districts the ground water is in general high chloride content in upper aquifer in Subarnarekha basin 8-100m, in Haldia area, Kasai basin 40-115m, in South 24 Parganas and Haora districts 20-150m depth range and higher specific conductance (>1500 mmho/cm at 250C).
	Aquifers occurring in the depth span of 115 to 300m in Digha area, 125-300m in Haldia area and 170-350m in South 24 Parganas district are relatively fresher and chloride content of ground water is within permissible limit.