Recreational use advisory downgraded to a precaution for Prineville Reservoir

Prineville, Ore. (KTVZ)-- The Oregon Health Authority downgraded the recreational health advisory for Prineville Reservoir to a precaution today. Water testing confirmed that cyanotoxin levels in the Crook County reservoir have fallen below recreational guideline values for humans.

The initial health advisory for the reservoir was issued on July 27. Although toxin levels no longer exceed threshold guidelines for human recreation, cyanotoxin levels remain above state educational guideline values for dogs. Health officials advise pet owners to keep animals away from any areas showing signs of an active bloom.

Recreational visitors should remain alert for visible signs of cyanobacteria blooms, which can form or disappear rapidly whenever conditions are favorable. People and pets should avoid water that appears foamy, scummy, thick like paint, pea-green or blue-green. Visitors should also stay clear of areas containing thick brownish-red mats or bright green suspended clumps. Activities such as swimming or motorized and non-motorized boating that could cause people to swallow water or inhale droplets should be avoided around these blooms.

State health officials noted that cyanotoxins can exist in clear water surrounding a bloom. When cyanobacteria die, released toxins can spread into adjacent clear water, or wind can push blooms to new areas while leaving toxins behind. Certain species of cyanobacteria also live in sediment, anchor to the bottom of a water body or grow on aquatic plants, releasing toxins into otherwise clear water.

Because officials monitor only a fraction of water bodies across the state for toxins, visitors are encouraged to learn how to identify harmful blooms and recognize exposure symptoms. Health inquiries or reports of illness can be made to the Oregon Health Authority by calling 971-673-0482. Additional educational resources regarding harmful algae blooms are published on the agency's website at http://www.healthoregon.org/hab.