Investigation of Groundwater Contamination from Septic Tank Siting in Umungasi/Abayi, Abia State

Abstract

The investigation of groundwater contamination from septic tank siting was done in Umungasi/Abayi, Abia State. The aim of this study was to investigate the effect of siting septic systems on the quality of groundwater in Umungasi, Abayi, Aba. Twenty (20) water samples were randomly collected from boreholes located less than 30 m away from septic systems in Umungasi, Abayi Aba, Nigeria to determine their physico-chemical and heavy metals characteristics. While three (3) water samples at distances ranging from 60 m from the nearest septic system were sampled for analyses as controls. Standard analytical techniques were employed in the investigation. The result showed that most of the physicochemical parameters analysed in the borehole water samples were within the WHO/SON/NAFDAC recommended limits except for pH in BH4 and BH7 which had values of 6.3 respectively and were not within the WHO/SON/NAFDAC standard limit of 6.5-8.5. Some of the heavy metals analysed during the period of study were within the permissible limits except for iron in BH5 (0.443 mg/L), BH7 (0.367 mg/L), BH8 (0.511 mg/L), BH9 (0.31 mg/L), BH15 (0.41 mg/L), BH16 (0.327 mg/L), BH17 (0.337 mg/L) and BH18 (0.315 mg/L) that were above the permissible limits of WHO standards of 0.3 mg/l. There was no influence of septic tank siting to the boreholes on groundwater quality during the period of study even though the distance of septic tanks from boreholes in the areas investigated did not conform with that recommended by WHO of 30 – 40 m. The contamination is from the general unhygienic condition of the environment.