Role of geophysical and hydrogeological techniques in EIA studies to identify TSDF site for industrial waste management

This paper deals with the importance of integrated hydrogeological, geological and geophysical applications in identifying suitable site for treatment, storage and disposal facility (TDSF) for industrial waste management. The pollution control authorities (Civic body) have a mandate to provide proper TSDF for the industrial zones. One such zone of 2800 acres, established by State Industries Promotion Corporation of Tamil Nadu (SIPCOT) at Perundurai in southern India, is selected to identify suitable TSDF site. The zone is envisaged to cater 22500 MTA (metric tones per annum) of industrial waste generated by 565 units. Hydrogeological and geological setup forms an important criterion in the process of environmental impact assessment (EIA) to establish proposed activity. Hydrogeological, geophysical and socio-economic/ecological studies were carried out to identify suitable TSDF site. Vertical electrical sounding (VES), multi-electrode resistivity imaging (MERI), ground penetrating radar (GPR) scanning, and infiltration tests were performed within the proposed TSDF site of 50 acres land. An inventory of 54 key wells includes depth to water level (varies from 9.7 to 15 m, below ground level) and water chemistry (pH, TDS, Ca²⁺, Mg²⁺, Na⁺, K⁺, Cl^?, HCO ₃ ^? , SO ₄ ^2? , NO ₃ ^? and F^?) helped in identifying physical environment around (5 km radius) proposed TSDF site. Geophysical and hydrogeological investigations verified with drillings (at 5 locations) within the proposed TSDF site resulted, shallow hard rock at 4.5 m depth, the absence of groundwater, and low infiltration rate (4.3 cm/hour) of soil in the western side (45 acres) of proposed 50 acres land reveals suitability of TSDF site.