Near the beginning of the popular Airport Dike Trail, a big pipe juts into the Mendenhall River. Ducks quack and do laps near the gurgling pipe, which is exposed when the river is low. If the ducks could read the sign up on the river bank, they’d know they’re swimming around in water straight from Juneau’s biggest sewage treatment plant.
“I would not let my dog play in that water,” said Guy Archibald, a wastewater expert and staff scientist with the Southeast Alaska Conservation Council.
Most of Juneau relies on the Mendenhall Wastewater Treatment Plant to process sewage. But the facility has struggled in recent years to keep the treated water it pipes into the Mendenhall River clean enough for environmental regulators.
City-hired wastewater experts figured out some of the problems. But one mystery is why a system that serves roughly 20,000 people is producing sewage they’d expect from about 50,000.
There are several regulated pollutants the plant isn’t consistently meeting its discharge limits on. The one that’s a direct concern for people’s health is a bacteria called fecal coliform.
“Fecal coliform in and of itself can cause illness,” Archibald said. “But the fecal coliform test is actually — they call it an indicator organism.”
Meaning, if there’s fecal coliform in the water, that’s a strong indication that other, more harmful bacteria and viruses are, too.
On some days in recent years, the plant has piped water into the river with fecal coliform levels two, three and four times the permitted limit. On one day in December 2018, it was 156 times its permitted limit.
Archibald said he isn’t necessarily worried his dog would get sick — our canine companions are pretty resilient to stomach bugs that harm people.
“But again, that dog comes out, then it jumps into the backseat of your car, maybe next to where you have your child strapped down in the car seat, you know?” he said.
Public health officials track outbreaks of many illnesses, including those associated with fecal coliform. Fortunately, Alaska Department of Health and Social Services spokesperson Clinton Bennett said none have been identified or reported in Juneau over the last several years associated with what’s coming out of that pipe.
Juneau wastewater engineer Lori Sowa said the fecal coliform discharge violations occurred when the plant was in an “upset.” That could mean the amount of sewage coming into the plant ramped up abruptly. If there’s too much, too fast, the plant has to spend less time treating wastewater…