Portland switches to groundwater supply after Cryptosporidium found in Bull Run water

The Portland Water Bureau has switched to using 100 percent groundwater from the Columbia South Shore Well Field after Cryptosporidium was found in the Bull Run watershed.

The bureau says the action wasn't required and is being made out of an abundance of caution. Low-level detections of Cryptosporidium in the Bull Run watershed were reported several times during the past month.

"The recent detections do not pose an increased health risk. After a series of very low level detections, we are proactively activating our secondary source while we collect more data," Water Bureau Administrator Michael Stuhr said in a news release. "The city continues to be in compliance with the treatment variance issued by the Oregon Health Authority."

As for where the microorganisms are originating, officials haven’t found a specific source, but say it is likely from wildlife scat that has washed into the reservoirs because of the recent storms.

Portland doesn’t treat for the parasite, as it has a variance from the Oregon Health Authority. But it is required to test for the parasite twice a week and notify the public when the microorganisms are detected. The city said since the most recent detections, it has increased testing to at least four times a week.

The city reported six parasites were found in the Bull Run watershed in January. Earlier this month, it reported that another one was found in a water sample. In the latest sampling last week, three were found.

While the health risk is low, officials advise those with severely weakened immune systems to seek advice from a doctor.

The symptoms of cryptosporidiosis, the disease caused by Cryptosporidium, include diarrhea, nausea, vomiting, stomach cramps and fever.

According to Multnomah County Deputy Health Officer Dr. Jennifer Vines, there have so far been no increase in Cryptosporidium cases.

close video ad
Unmutetoggle ad audio on off