TITLE:
Assessment of Physicochemical Properties of Groundwater near Oil Well Pads in Lokichar Basin, Turkana County, Kenya
AUTHORS:
David Mbugua, Mary K. Makokha, Chris A. Shisanya
KEYWORDS:
Groundwater Quality, Produced Water, Salts, Heavy Metals
JOURNAL NAME:
Open Access Library Journal,
Vol.9 No.3,
March
16,
2022
ABSTRACT: Oil mining wastes such as Produced water, drilling muds and cuttings may lead to contamination of groundwater. The study investigated whether Produced water from the oil well pads in south Lokichar basin, Turkana County, Kenya, leads to contamination of the neighboring groundwater resources. The specific objectives of the study were to 1) determine the physicochemical properties of Produced water and 2) determine the physicochemical properties of boreholes water near oil well pads. Produced water was found to be highly contaminated since all the selected physicochemical parameters exceeded the set drinking water quality standards. The computed Water Quality Index of 4030 found for the Produced water indicated that it was unsuitable for drinking purpose. Produced water heavy metals and salts levels that were found to be predominant exceeded acceptable water quality standards as follows: lead by 15,680%, zinc by 22%, iron by 16,567%, chlorides by 8128%, fluorides by 2500%, and nitrates by 480%. This was attributed to the usage of production chemicals to enhance oil recovery through hydraulic fracturing. Out of 11 groundwater samples analysed, eight were found contaminated with high levels of heavy metals and salts exceeding set drinking water quality standards. Nalemsekon borehole iron levels exceeded allowable standards by 250%, chloride 10.4% and fluoride 148%. RCEA borehole lead levels exceeded standards by 1500%, while fluoride 56%. Nakwakipi borehole lead levels exceeded by 5180%, nitrate levels 287%. Nakukulas 10 borehole zinc levels exceeded by 51%, nitrate 111%. Nakwakitela borehole fluoride levels exceeded by 36%, nitrate levels 428%. Nitrates levels at Irir 1, Chinese 1 and Nawoyatira boreholes exceeded standards by 604%, 463% and 322%, respectively. The high levels of heavy metals and salts observed in these boreholes was as a result of oil mining wastes contamination since these boreholes were in close proximity to the oil well pads.