The Bull Run Watershed: Now with more poop.
The Bull Run Watershed: Now with more poop. City of Portland

You've now got two new treatment plants potentially coming to your water bill, Portland.

The Portland Water Bureau (PWB) announced this morning it will finally need to treat the city's water supply for a microscopic, poop-loving organism called Cryptosporidium, at a price tag that could well exceed $100 million.

Crypto can cause violent stomach illness if ingested, and can kill people with depleted immune systems. A particularly awful outbreak in Wisconsin in 1993 killed nearly 70 people.

Cities around the country already routinely fry Crypto in their water supplies—they're required to do so under a 2006 federal rule—but Portland's had something of a hall pass for the last five years. By showing the Oregon Health Authority that the Bull Run Watershed where the city sources much of its water maintains acceptably low levels of the parasite, Portland became the only city to get an official variance to the federal rules.

That string of good luck ended this winter, when the parasite popped up more than a dozen times between January 1 and early March. The repeated detections—often attributed to the ultra-hard rains washing more animal feces into the watershed—caused officials to temporarily draw water from a secondary source. But they also led the city to a conclusion: It could no longer qualify for the waiver.

Officials revealed today that the PWB sent a letter to the state on March 8, saying that the repeat detections of Crypto had made it "infeasible" that the city could prove the parasite was no longer a problem.

"We said that our water untreated was safer than systems that treated their water," says City Commissioner Nick Fish, who oversees the PWB. "It became hard for us to say that this winter. That’s what changed."

In order to even try to prove by January 2018 that the parasite was sufficiently dilute in the water supply, the PWB letter said, officials would need to test thousands of more liters of water per week than they already were. "This volume is infeasible to sample and test over the remaining period of demonstration monitoring due to logistics, personnel resources and laboratory capacities," the letter read.

Fish wasn't clear on what such testing might cost. The upshot is that, instead of trying to beat the rule, the city's now facing down a treatment project that will cost tens of millions. On May 19, the Oregon Health Authority sent formal word that the city's variance to the Crypto rule had been revoked. The city has until August 11 to come up with a plan for how to treat its water and eliminate the threat.

Officials have had that conversation before. Prior to applying for a variance in 2011, the city had extensive conversations about how to treat for Crypto. It's preferred option at the time: A treatment facility that would use ultraviolet light to kill the parasite, and might cost up to $100 million. That price tag has likely increased in the years since.

"I was on the council when we fought for that variance," says Fish. "I oppose spending money unnecessarily."

But he notes: "If we were to have Crypto health outbreak that resulted in significant health problems like death, people would wonder why we were slicing this so thin."

It's not clear that the current city council will decide ultraviolet treatment is the way to go again—or even that a majority of council won't just opt to flout federal rules. Expect that conversation to play out in relatively rapid fashion in order to satisfy state deadlines.

And also count on your water bill increasing. The city is already talking about spending something like $15 million on a water treatment facility to help contain lead exposure in the city. Any plant to treat for Crypto would be separate.