PENDLETON — Algae blooms in Oregon’s waterways hamper recreation and cause crises when found in sources for drinking water. To keep people and their pets safe, federal and state agencies work together to inform the public and test for potentially deadly toxins.
Two suspected algae blooms were tested in the last two years on the Umatilla National Forest — Penland Lake east of Ukiah in 2017 and a stock pond near a popular dispersed campsite south of Forest Service Road 5412 on the North Fork John Day Ranger District.
“We ended up testing the water both times,” said Umatilla National Forest Public Affairs Officer Darcy Weseman.
Weseman said the Penland sample was low enough that there were no concerns for recreational use of the water. At the cattle pond, she said they found a single filament of cyanobacteria in the sample, but no toxins.
According to the U.S. Forest Service Pacific Northwest Implementation Plan for Recreational Waters on Forest Service Lands in Oregon 2019, water bodies in Oregon with histories of harmful algae blooms and areas with suspected blooms are posted with signs from the Oregon Health Authority. As time permits, forest field staff will monitor for reduced water clarity, changes in color or the presence of surface scum on the water, and sample water quality to test for toxins.
If tests come back indicating a high level of toxins, the Implementation Plan said the forest will share the information with state and county health agencies responsible for harmful algae bloom guidance.
“If a potential harmful algae bloom is located by someone — Forest Service staff or a forest user — our hydrologist or someone else in the watershed group will confirm that it could be an algae bloom, and if it is, post the signs,” Weseman said. “If it’s at Bull Prairie, Twin Ponds or Olive Lake, we’ll also test the water.”
Cyanobacteria are naturally occurring, but warmer temperatures increase blooms and toxic chemical compounds can be released.
According to Laura Gleim, public affairs specialist at Oregon Department of Environmental Quality, blooms are most common in the summertime since warm water and sunlight lead to blooms.
Gleim said a variety of agencies are involved when a bloom is suspected.
“It is one of those big complex problems — there is not one kind of agency that can address all the problems,” she said.
A lot of times it is Oregon Health Authority that issues the advisories on swimming, other recreation and drinking water concerns, Gleim said. If the suspected bloom is in drinking water, the local municipality would oversee the testing and work with the health authority.
Testing an algae bloom is triggered by a complaint, Gleim said, and not all algae is harmful — so the tests determine whether there is a need for concern.
“If someone sees something developing, sampling is done,” Gleim said.
Two heavily used reservoirs bordering Oregon and Idaho have historically high levels of harmful algae blooms — Hells Canyon and Brownlee reservoirs on the Snake River. Those two problem areas are managed by the state of Idaho.
In July, the Southwest District Health and Idaho Department of Environmental Quality issued an amended health advisory for Brownlee Reservoir from the area of Canyon Creek on the Oregon side to Brownlee Dam, urging residents to use caution when recreating in or near the water. Recent samples indicate high concentrations of toxin-producing cyanobacteria, which can be harmful to people, pets, and livestock. Those with liver or kidney damage are at an increased risk of illness.
A month later the agencies issued a similar health advisory for Hells Canyon Reservoir from Copper Creek down to Hells Canyon Dam.
Blooms vary in appearance and may look like mats, foam, spilled paint or surface scum and have a foul odor, according to the Idaho advisories.
To avoid contact with potential toxins, the Idaho advisory said to avoid swimming and wading and ensure children, pets and livestock are not exposed to the water; do not drink or cook with water — boiling and filtering the water can increase the risk of exposure to toxins. Eating fish out of the reservoirs is discouraged. Symptoms of cyanotoxin exposure include rashes, hives, diarrhea, vomiting, coughing, and/or wheezing. More severe symptoms affecting the liver and nervous system may result from ingesting water.