A recreational use health advisory has been issued for higher-than-normal levels of bacteria in ocean waters Wednesday morning for Cannon Beach.
Water samples show levels of fecal bacteria at 262 mpn, or most probable number, a testing method used to estimate the number of colony forming units of bacteria. Anything above 130 mpn is considered unsafe, according to the Oregon Beach Monitoring Program.
High readings in ocean waters can come from sources such as stormwater runoff, sewer overflows, failing septic systems, and animal waste from livestock, pets and wildlife, according to the Oregon Health Authority. Officials advise people to avoid contact with the ocean, as well as nearby creeks and contaminated water runoff, as waterborne bacteria can cause diarrhea, stomach cramps, skin rashes, upper respiratory infections and other illnesses.
Even if there is no advisory in effect, officials recommend avoiding swimming in the ocean within 48 hours after a rainstorm.
The advisory — the first of the year — comes weeks after the city decided to reinstate a water testing program following high bacteria readings at the Chisana Creek and Gower Street outfalls. While the city has seen high readings on-and-off throughout the summer at these outfalls, advisories are only issued for contaminated marine waters.
City Manager Bruce St. Denis said water samples have shown a few high readings at the outfalls after rain events but can’t confirm whether or not this is a contributing factor to the current advisory in marine waters.
The city is unaware of any specific events that would trigger the reading, St. Denis said.