South Dakota lake closed to swimming due to harmful bacteria
District Park Supervisor Jason Baumann says that routine water testing at the Lake Alvin Recreation Area near Harrisburg showed that the bacteria could pose a health problem for people submerging and ingesting the water.
He says runoff from heavy rains picked up the contaminants. Baumann adds that the bacteria usually dissipates quickly because of natural filtration provided by the lake.
The Argus Leader reports that the lake remains safe for fishing.