Sources of bacteriological contamination of shallow groundwater and health effects in Ndop plain, Northwest Cameroon

Shallow groundwater of unknown bacteriological quality is a vital source of drinking-water to about 70 % of ca. 200,000 people in the semi-urban community of the Ndop plain, Northwest Cameroon. Seventeen drinking-water sources were investigated, in March 2010, for bacteriological quality by a multiple tube/MPN technique. Temperature, pH, electrical conductivity (EC) and total dissolved solids (TDS) were also determined. The objectives were to determine the potential sources of bacterial contamination, suitability of water for drinking and effects on the population. Microbial analysis indicated high total coliform (TC) counts from 23 to >1,100 MPN/100 ml, with 94 % of the samples being grossly polluted. The major source of microbial contamination was cattle grazing. The groundwater, which was less mineralised (mean TDS of 45 mg/l), had a mean pH (5.89) below the WHO minimum value of 6.5. Based on WHO standards, the water sources were not suitable for human consumption as further established by the high prevalence of water-borne infections from health centre data in the area. The most vulnerable were children below the age of 10, mostly suffering from diarrhoea.