Assessment of Groundwater Decontamination Processes around a Dismantled Septic Tank Using GIS and Statistical Analysis

Septic tanks without proper construction and insulation entail a significant risk to the environment. In this study, environmental impacts of permeably designed septic tank on shallow groundwater contamination are investigated, changes in water quality period after its elimination 2014 assessed. For purpose evaluating pollution level site, 10 monitoring wells were installed around 2012 long-term was carried out. Analytical measurements revealed operational tank. Extremely high concentrations NH4+ (>90 mg/L) observed closest wells, most exceeded relevant limit. δD δ18O isotopic ratios within 1 m from indicate continuous recharge sewage originating deeper aquifers. The dome resulting wastewater discharge 1.1 m, distance 25 m. Statistical analyses also depending well location elimination, considerable have been detected. Following cessation discharge, disappeared; therefore, differences levels decreased more than few cm. Significant positive detected parameters investigated dismantling Five years pollutant supply, still limit indicating slow decontamination processes with permanently pollution.