MPCA releases draft WLSSD wastewater permit

Contact: Anne Moore, 218-302-6605 or Ralph Pribble, 612-757-2657

Duluth, Minn.— The Minnesota Pollution Control Agency has released a draft of the wastewater permit for the Western Lake Sanitary Sewer District. The action is a five-year reissuance of the facility’s permit to discharge treated wastewater to the St. Louis River Bay. MPCA is inviting the public to review and comment on the permit through Dec. 5, 2014.

The draft permit includes changes for two important regulated pollutants — mercury and fecal coliform. MPCA Wastewater Manager Wendy Turri said that the agency wants to make sure the public is well aware of this draft permit, especially since the issue of mercury in the St. Louis River is a sensitive topic. She also praised the facility for the work it has done to protect Lake Superior and the bay.

“Lake Superior is protected by some of the strictest discharge standards for mercury in the state,” Turri said. “The district has worked very hard to get the mercury levels in their discharge down to extremely low levels. Despite that, they can’t quite meet the current mercury standard,” she said. 

Therefore the draft permit includes a provision that authorizes the district to discharge mercury at a level higher than current standards allow, while requiring them to work toward full compliance.

Installing the technology to fully control for mercury is not yet feasible for the district, and attempting to do so at this time would mean unacceptably high increases for the district’s rate payers.  So the draft permit contains a variance with a five-year schedule for compliance. 

“They’ve made great progress, but they need some more time,” Turri said.

The draft permit also recognizes the district’s success in controlling fecal coliform levels by allowing them to cease winter disinfection of the discharge.

State rules require dischargers to disinfect year-round if they are within 25 miles of drinking-water intakes. But the district is well within the coliform standard, particularly in the winter. Because chlorination creates potentially toxic byproducts, the MPCA prefers not to have dischargers chlorinating needlessly if they are meeting standards. 

The district’s discharge is within 25 miles of drinking water intakes, so “a variance is the only legal way to release them from that obligation,” Turri said.

Turri said the draft permit contains additional monitoring and intervention requirements to ensure protection of downstream drinking water intakes and any potential risk to humans from fecal coliform exposure.

“Especially with all the interest in the St. Louis River and mercury in fish, we encourage people to become informed about this draft permit and the district’s efforts to protect Lake Superior and the St. Louis River,” she said. “There’s a lot going on to try to control mercury in our state’s waters, and we welcome the public’s comments on the draft permit during the public notice period.”

The draft permit is available at http://www.pca.state.mn.us/yrwc6a9. The MPCA will accept public comments through Dec. 5, 2014. Comments should be sent to the attention of Nancy Drach at the MPCA, nancy.drach@state.mn.us or 651-757-2317.