Evaluation of groundwater quality in an untreated wastewater irrigated region and mapping—a case study of Avaniyapuram sewage farm, Madurai

Abstract

The present study focused on evaluation of groundwater quality in Avaniyapuram Sewage Farm, Madurai. Totally, 45 groundwater samples were collected with different zones during pre-monsoon (PRM) and post-monsoon (POM) seasons, respectively. All the samples were analyzed as well as the various physical and chemical parameters like pH, electrical conductivity, total dissolved solids, total hardness, total alkalinity, and major cations such as, Ca2+, Mg2+, Na+, major anions such as NO3 −, SO4 2−, F−, and Cl−, and were compared with the standard guideline limits by WHO, ICMR, and BIS. Results indicated that the pH, EC, TDS, hardness as CaCO3, alkalinity as CaCO3, Ca2+, Mg2+, Na+, and Cl−, level in groundwater samples were above critical limits and it was found to be very high in the first 1–3-km range with epicenter of ASF. Box plot illustrates that seasonal effect slightly changes the order of abundance of both cation and anion. Hydrogeochemistry is studied to determine the ionic interaction for evaluating the hydrochemical processes. The correlation coefficient results illustrate that Cl− is strongly correlated with major cations and anions cause salinity. The geochemical data was interpreted using WQI in relation to drinking water quality proved that all the water samples were found to be poor and 60% of the samples are not suitable for drinking purposes and SAR, %Na, and MH shows that 50–60% of the groundwater samples were found suitable for irrigation. The results concluded that groundwater quality is 60% suitable for irrigation and poor for drinking; this may due to long-term use of wastewater irrigation.