Microcystin algal toxins in Source and Finished Drinking Water

Abstract

The number and intensity of reported blue‐green algae (cyanobacteria) blooms in reservoirs, lakes, ponds, and rivers have increased worldwide. Some species of cyanobacteria are capable of producing microcystins, hepatotoxins that can cause liver damage, shock, and in some cases, death to mammals ingesting contaminated water. In 1998 and 1999, studies were conducted to elucidate the occurrence of microcystin toxins in raw and finished water from five drinking water treatment facilities in Wisconsin. Samples were collected and analyzed for microcystins using an enzyme‐linked immunosorbent assay. Microcystin toxins were repeatedly found in the raw water. Conventional water treatment practices used by the facilities effectively removed microcystins by 1‐3 logs. The data collected suggest that microcystin toxin removal occurs incrementally at several points in the drinking water treatment train.