Evaluation of physico-chemical quality of groundwater in the surroundings of Valiathura sewage farm in Thiruvananthapuram District, Kerala, South India

Abstract

The present study was conducted to determine the changes in the physico-chemical characteristics of the groundwater in the surroundings of the sewage farm in Valiathura, Thiruvananthpuram district, Kerala. For this, 42 groundwater samples (29 dug wells and 13 bore wells) were collected bimonthly from the study area during the period January to December 2010 covering pre-monsoon, monsoon and post-monsoon seasons and the major physico-chemical parameters were analysed. The values recorded for parameters such as total alkalinity (330 mg/l), potassium (63.40 mg/l), magnesium (52.39 mg/l) and phosphates (4.71 mg/l in dug wells at some stations exceeded the desirable limits for drinking water quality prescribed by WHO and BIS standards. The Sodium Adsorption Ratio (0.20 - 6.33), Percent sodium (8.54 - 71.83) and Permeability Index values (48.07 - 119.35) showed that all the groundwater samples in the study area were suitable for irrigation purposes. The study revealed that about 31% of the dug wells adjacent to the sewage farm and Parvathy Puthen Ar canal were moderately contaminated and consumption of water from these wells may lead to various health problems in residents. As nutrients like phosphates, sodium, potassium, magnesium were high in well water samples and prolonged consumption of nutrients enriched well water may cause health problems such as high blood pressure, bowel cancer (due to phosphates), cardiovascular diseases (due to sodium and magnesium), renal diseases (due to sodium and potassium).Therefore effective management measures should be taken to protect the groundwater sources in Valiathura area.

Keywords

• correlation analysis
• groundwater quality
• irrigational quality
• physico-chemical parameter
• sewage farm