Assessment of Domestic Water Quality of Dams in Chepalungu Sub-county, Bomet County, Kenya

Abstract

An assessment of domestic water quality for six selected dams in Chepalungu sub county, Bomet County was carried out by determining the levels of pH, total dissolve solids, total suspended solids, nitrates, ammonia, fluoride, phosphorous, copper, lead, zinc, cadmium and chromium in the 6 selected dams, and their concentrations was compared with the World Health Organization (WHO) and National Environmental Management Authority (NEMA) Kenya water quality guidelines for sources of domestic water.  These dams are the alternative source of household water since the appreciably large neighboring population is unable to get access to chlorinated drinking water supply, for safer use. Water samples were therefore taken from 6 selected dams. Three sampling points was identified in each of these dams and the samples were subsequently collected during the day. The sampling exercise was carried out during the dry season in September 2016 and the wet season April, 2017. Quantitative determination of each parameter was carried out using standard procedures. This report shows that pH level was within the recommended range by WHO and NEMA, Total dissolve solids were below the maximum recommended value with a range of between 87.9mg/L and 184.9mg/L, Total suspended solids ranged between 8.91mg/L and175.9mg/L which was higher than the maximum allowable level of 30mg/L, Nitrates ranged between 2.71mg/L and 11.50mg/L which was lower than the maximum recommended value by WHO (50mg/L) but slightly higher than that of NEMA (10mg/L), Phosphorous ranged between 0.61mg/L and 6.26mg/L, Ammonium ranged between 0.13mg/L and 0.55mg/L, Copper ranged between nil and 0.96mg/L which was lower than maximum recommended value by WHO (2mg/l) but slightly higher than that of NEMA (0.05mg/L), Zinc ranged from 0.07mg/L to 4.99mg/L which is higher than maximum recommended value by WHO (3mg/L), while lead were not detected in all dams except Kapewot during dry season with a concentration of 0.87mg/L which was higher than the maximum recommended value by WHO, Lead was detected during dry season in two dams only Cheboloigo and Kapewot with concentration of 0.46mg/L and 1.98mg/L respectively, Fluoride was higher than the recommended level of 1.5mg/L by both NEMA and WHO it ranged from 1.25mg/L to 5.33mg/L which indicates high fluorides in the area. According to analysis high fluoride originates from soil in the area, soil from this area has high concentration of fluorides with a range of between 125mg/L to 683mg/L. Water treatment is recommended to avoid long term adverse effect of high fluoride concentration alternatively local population can use rain water since according to analysis of rain water, these pollutants are below the detection limit except zinc which originate from iron sheets which is coated with aluminum and zinc.