Douglas Corp. plans to install underground tanks to prevent chemicals from running from its St. Louis Park facility into Lake Calhoun.
The Minnesota Pollution Control Agency traced contamination in the Minneapolis lake to the metal plating company, according to the agency.
University of Minnesota researchers found perfluorooctane sulfonate, or PFOS, in Lake Calhoun in 2004, leading the pollution control agency to test fish and storm water samples. The Minnesota Department of Health issued a fish consumption advisory for Lake Calhoun that is still in effect.
The agency traced the chemicals to the company in 2008, according to St. Louis Park Planner Jennifer Monson.
“From 2008 to 2017, the Douglas Corp. has worked with the Minnesota Pollution Control Agency to stop this pollution and establish a monitoring program,” Monson told the St. Louis Park City Council March 20.
During the council meeting, the city council approved a plan to excavate enough soil to fill 180 trucks, allowing Douglas Corp. to install two tanks that will collect rainwater captured from the roof of the facility at 3520 Xenwood Ave. The rainwater will be pumped into the facility for treatment and reused in the industrial process, according to a city staff report.
The MPCA approved the plan aimed at protecting surface water and groundwater in the area last year.
The company used chemicals in the manufacturing process that contaminated storm water until 2010, according to the agency.
“Once the company realized their potential harm, they ceased using the products and found alternatives; however, the chemicals accumulated on the roof,” a city document states. “Since 2010, Douglas Corp. has worked with the MPCA to replace the roof, roof vents, tanks and other structures, but there are still traces of pollution on the property contaminating storm water runoff.”
Douglas Corp. used the chemicals to comply with the Clean Air Act by reducing chromium air emissions, said John Fudala, who manages the St. Louis Park facility for Douglas Corp.
“They reduce surface tension,” Fudala explained to the City Council. “They’re extremely stable in a very harsh chemical environment, and that’s one of the reasons why they are substances of concern because they are so stable they last forever.”
A statement from the MPCA last year concluded that fumes vented to the roof caused PFOS and chromium, another contaminant found in Lake Calhoun, to accumulate on the Douglas Corp. facility’s roof. The high levels on the roof then contaminated storm water as a result of rain and melting snow.
Groundwater at the facility and nearby is contaminated with PFOS and chromium at levels that exceed the state health department’s health risk levels for drinking water, the pollution control agency said in its statement.
“However, PFOS has not been detected in nearby municipal drinking-water supply wells,” it adds.
While Fudala said PFOS can be found in products like firefighting foams and microwave popcorn packaging, Councilmember Tim Brausen observed that the solution for air emissions that Douglas Corp. used became part of another problem – a sentiment with which Fudala agreed.
The company that sold Douglas Corp. the product used at the facility had not been obligated to inform Douglas Corp. that it contained PFOS because they had not been considered hazardous at the time, Fudala said.
Once Douglas Corp. learned of the problem, Fudala said managers of the St. Louis Park facility found a substitute. While he said that the company replaced the facility’s roof and every plumbing fixture that water runoff containing the chemicals had touched, Fudala said that reducing the chemical content to the level the pollution control agency expected would not have been feasible.
“The only way we could think to eliminate the release was to reuse the water in our process, treat it in our waste treatment process and then discharge it down the sanitary sewer,” Fudala said.
Doing so will bring the company into full compliance with the pollution control agency’s requirements, he said.
While the chemicals have impacted shallow groundwater near the facility, he said they have not extended lower than the bedrock in the area.
“We put a bedrock well in this past fall right at the facility, and it was non-detect for all substances of concern,” Fudala said.
A legally binding agreement Douglas Corp. reached with the MPCA last year called for the company to continue monitoring storm water leaving its facility. Douglas Corp. must either capture storm water before it can leave the facility or treat PFOS in storm water to a level that is below the pollution control agency’s limit for Lake Calhoun. The agreement also required the company to investigate the extent of groundwater contamination and begin cleanup efforts if necessary.
The company would have to pay daily fines of $500 per violation if it fails to stop the problem.
The underground tanks will be installed beneath an existing parking lot, Monson said. Construction will begin in May or June and last about a month. Douglas Corp. is working with other property owners to find parking for employees during the construction.
About 135 employees work at the facility. Douglas Corp., which is based in Eden Prairie, employs about 600 people across the metro area.
Because Douglas Corp. does not meet St. Louis Park’s current zoning rules for the number of parking stalls and landscaping, the city will require the company to add three trees to the site to bring it closer to compliance. While the city code would require the addition of 17 trees to the site, a city staff report states, “Adding more trees than proposed is not feasible due to the location of existing canopy trees and overhead utility lines.”
City code would generally require 61 vehicle parking spaces instead of the existing 33 spaces, but the city staff report states, “It is not feasible or necessary to require additional vehicular parking facilities.” The city will require the company to add parking for six bicycles.
The city will limit the hours when trucks can move soil during the construction period to 8 a.m.-5 p.m. weekdays except if special circumstances arise. Trucks will primarily use Xenwood Avenue, West 36th Street, Wooddale Avenue and Highway 100. Monson said she did not anticipate the trucks would cause significant traffic impacts.
Councilmember Anne Mavity said the Elmwood Neighborhood “has certainly been hit over the years” as a result of industry in the area.
Mavity said, “I appreciate that these changes are being made.”
In nearby Lake Calhoun, the state’s fish advisory recommends restricting consumption of the lake’s largemouth bass to one meal per month as a result of mercury and PFOS contamination. The guidelines are less strict for other species. The recommend suggests limiting consumption of bluegill sunfish, crappie and northern pike to one meal per week. Walleye consumption is also restricted based solely on mercury contamination, according to the guidelines. They call for fishers to limit consumption of walleye larger than 20 inches to one meal per month and smaller walleye to one meal per week.
The guidelines recommend that women who are pregnant or may become pregnant and children under age 15 eat largemouth bass, northern pike and walleye 15 inches or longer in Lake Calhoun no more often than once per month as a result of PFOS and mercury contamination in the lake. People in the population category should also eat white sucker no more than once per week, according to the guidelines.
Contact Seth Rowe at [email protected]