Parasite found in Portland drinking water

PORTLAND, Ore. (AP) — Officials say a trace amount of cryptosporidium parasite has been found in a test of Portland drinking water for the fourth time this year.

The Oregonian/OregonLive reports ( ) the parasite was found Monday in the Bull Run watershed, Oregon's largest source of drinking water.

The Portland Water Bureau says the finding doesn't raise immediate alarms for human health but recommends that people with weak immune systems consult their doctors.

The water bureau's quality manager Yone Akagi says it "is the most cryptosporidium we've detected in more than a decade."

Unlike in most cities, Portland's water bureau doesn't treat its water for cryptosporidium, a parasite found in animal and human waste. says "this bug's also called 'crypto,' and it affects your intestines. It’s spread by contact with the stool of an infected person or animal. People tend to catch it from pool water, especially kids. The diarrhea it causes can last a long time, but it usually goes away on its own without treatment."

Officials say the bureau received an exemption in 2012 but more positive tests could force the construction of an at least $89 million treatment plant.