Washburn sewage back in complianceAfter 30 months of violating Wisconsin standards for sewage discharge into Lake Superior, the city of Washburn finally might have brought its sewage treatment plant back into compliance.
By: John Myers, Duluth News Tribune
After 30 months of violating Wisconsin standards for sewage discharge into Lake Superior, the city of Washburn finally might have brought its sewage treatment plant back into compliance.
It appears a complete shutdown, cleaning, inspection and restart of the plant in March might have been the solution to a problem that had vexed city and state officials for more than two years.
The plant remained in violation through May, but a lab report issued last week showed the plant’s wastewater finally below state limits for most pollutants.
Phosphorus levels dropped from 4.5 milligrams per liter in April to 0.3; total suspended solids dropped from 69 milligrams per liter to 15; and biochemical oxygen demand dropped from 60 milligrams per liter to 20 — all within state limits, said Lonn Franson, the Wisconsin Department of Natural Resources wastewater engineer in Hayward.
Fecal coliform levels — bacteria from human waste — also have declined markedly, from counts routinely as high as 30,000 to 60,000 colonies per 100 milliliters in past months to about 500 recently. State law requires a monthly average below 400, and Franson said he’s confident Washburn will get there for June.
“That’s outstanding progress, and it looks like they have finally turned the corner,’’ Franson said.
But the city isn’t out of the woods yet. Wisconsin rules require the city to meet all standards for nine months out of the last 12, so it will be another eight months until the state completely lifts a moratorium on new sewer connections in Washburn.
“The enforcement action is still ongoing,” Franson said. “We do have some leeway after four months of compliance to offer some exceptions, but this is a long road they have to go down.”
In addition to meeting state marks for pollutants, the DNR will require Washburn to form an action plan on how it will prevent the treatment plant from failing in the future.
The 15-year-old plant suddenly stopped working properly in December 2009, sending as much as 300,000 gallons of partially treated sewage into Lake Superior’s Chequamegon Bay every day. The DNR issued a notice of noncompliance to the city after four months of violations and, in June 2010, slapped a moratorium on new sewage mains or extensions or commercial hookups until the problem is solved.
There is no indication that the long-term violation caused any human health or environmental issues. County health officials say they will double the number of water samples taken and tested at Thompson’s West End Beach this summer, near where the city’s sewage is discharged, just to make sure there are no issues with increased bacteria that could make people sick.
DNR experts and private consultants were summoned to help solve the riddle of why the once-functional plant stopped working.
In essence, the bacteria that normally break down human and industrial waste and remove dangerous pathogens simply died off. Several efforts to import active sewage from Ashland and Bayfield to kick-start the Washburn plant failed.
In March, the city shut down the plant entirely, storing incoming sewage in a lagoon while the plant was cleaned and inspected. All equipment was checked by the manufacturers and technical malfunctions were eliminated as a cause. The city then brought in another round of active sewage sludge to kick-start the plant.
“That appears to be what eventually solved the problem,” Franson said. “It just took a few months for their activated sludge system to get activated again. We still don’t know what caused the problem in the first place.”
In an open letter e-mailed Wednesday to several people connected with the issue, Washburn Mayor Scott Griffiths said the city kept details of the plant malfunction mostly quiet for more than two years because authorities suspected that possible criminal activity had led to a toxic shock that killed the plant’s organisms used to break down waste.
“It is true that the issue was not widely publicized, but the reason for this is important to understand,’’ Griffiths wrote. The city’s efforts to find the source of the problem “included an investigation into the possibility that the contamination source may be an illegal methamphetamine lab. The city did not want to jeopardize that investigation by publicizing these suspicions."
Griffiths was critical of a News Tribune story June 3 that outlined the scope of the sewage plant malfunction and the effort to get the plant into compliance. He said it wrongly implied that Washburn’s waterfront was unfit for swimming because of the sewage problem, when no such connection has been made.