MISSOULA - The Missoula City-County Health Department (MCCHD) reports that following additional testing by state agencies, no significant presence of algal blooms in the Clark Fork River has been found.
MCCHD and Missoula Valley Water Quality District received numerous calls earlier this month stemming from social media posts that reported dogs dying after swimming in the Clark Fork River. The social media posts indicated the area of concern was the Jacob’s Island Dog Park in Missoula.
After an initial news report stated the owner or veterinarian could not be reached to confirm the social media posts, a dog owner reached out to the health department to report that one of their dogs had passed away and their other dog was ill. The dogs had recently been to the Harper’s Bridge Fishing Access site off Mullan Road.
Staff visually inspected the Harper’s Bridge Fishing Access site and did not find any indication of an algal bloom.
"However, due to heightened public interest and out of an abundance of caution, health department officials worked with the Montana Department of Environmental Quality (DEQ) and the Environmental Protection Agency (EPA) to sample for cyanobacteria and toxins," a news release states.
The results show there were no detectable toxins and that organisms common in slow-moving water — including zooplankton and algae and very low levels of a cyanobacteria species — were detected.
The EPA samples also did not detect toxins.
MCCHD reports that water samples were further corroborated by veterinary results that did not indicate the dogs’ death and illness were associated with toxins from harmful algal blooms.
The health department advises that any water that looks like green paint — or has an unusual smell — should be avoided. People should contact their doctor or veterinarian if they or their pet have been exposed to toxic water.
