Hydrochemical appraisal of groundwater quality for drinking and irrigation: a case study in parts of southwest coast of Tamil Nadu, India

Abstract The quality of groundwater standards in Muttom–Mandaikkadu coastal stretch is the focus present study, whose aquifers are particularly at risk due to intrusion marine water. Thirty samples were scrutinized for assessment physical and chemical parameters during January June. Hydrochemical characteristics spatially depicted understand spatial variations such as (pH, EC, TDS, Na + , K Ca 2+ Mg SO 4 2− HCO 3− Cl − ). Drinking water index based on those 11 irrigation Na%, sodium adsorption ratio permeability was used assess drinking irrigation, respectively. These results demonstrate that dominant hydrochemical facies both months Na-K-Cl-SO type Ca-Mg-Cl-SO type. USSL diagram endorses most belong low-medium salinity with low hazards. /HCO 3 indicates majority show moderate seawater study area. Additionally, six vertical electrical sounding measuring points (Schlumberger array) carried out order determine number underlying layers, aquifer depths their thicknesses well its influence by geophysical self-potential measurements suggest Manavalakurichi area prone contamination intrusion, confirmed use Schlumberger sounding. For better understanding, subsurface layers shown a 2D model using constructed geoelectrical cross section.