Skip to Main Content View Text-Only

The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Ave, Suite 613, Portland, OR 97204

More Contact Info

Subscribe to RSS feed

Most Recent

View Less

Health advisory lifted September 1 for Willamette River's Ross Island Lagoon

Media contact: Oregon Health Authority, Jonathan Modie, 971-246-9139,

Health advisory lifted September 1 for Willamette River’s Ross Island Lagoon

Reduced blue-green algae cell counts and toxin levels confirmed

The Oregon Health Authority has lifted the health advisory issued August 19 for the Willamette River’s Ross Island Lagoon. Ross Island Lagoon is located about one mile south of downtown Portland in Multnomah County.

Water monitoring has confirmed that the number of blue-green algae cells as well as levels of associated toxins are below guideline values for human exposure.

Oregon health officials advise recreational visitors to always be alert to signs of algae blooms in Oregon waters. People and their pets should avoid areas where the water is foamy, scummy, thick like paint, pea-green, blue-green or brownish red in color, if a thick mat of blue-green algae is visible in the water, or bright green cells are suspended in the water column. If you observe these signs in the water, you are encouraged to avoid activities that cause you to swallow water or inhale droplets, such as swimming or high-speed water activities.

For health information, to report human or pet illnesses due to blooms, or to ask questions about a news release, contact the Oregon Health Authority at 971-673-0400. For information about advisories issued or lifted for the season, contact the Oregon Public Health toll-free information line at 1-877-290-6767 or visit the Harmful Algae Blooms website and select “Algae Bloom Advisories.”

# # #