Studies on well water and possible health risks in Katsina, Nigeria.

Well water was sampled from all four major wards in Katsina town. All 20 samples taken showed high coliform counts. Sixty-five per cent contained greater than or equal to 2400 coliforms per 100 ml while the remainder had counts ranging from 79 to 920. Faecal coliforms and non-cholera vibrios were detected in all samples. There was no significant relationship between the coliform counts and the distances of latrines to wells, water table to ground level, slope relationship between wells and latrines, the pH of water and whether the wells were left permanently open or not. Salmonella sp., Enterobacter sp. and Pseudomonas sp. were each isolated from about 10% of the samples, while Proteus sp. was isolated from 40%, Citrobacter sp. 15%, Alcaligenes sp. 5% and an unidentified Gram-negative rod from 5%. Only 2 (10%) of the sampled households, representing 23 (9.6%) of the 239 people exposed to well-water had pipeborne water in addition. It was concluded that well water in Katsina town could be a human health hazard.