A small vacant lot on Lowry Ave. could be a big source of pollution, says the Minnesota Pollution Control Agency (MPCA). Blame it on a dry cleaning operation that closed in 1981.
Once known as the only place in Northeast that could meet the exacting specifications of the U.S. Navy for dry cleaning and folding naval uniforms, Waldorf Cleaners operated at 942 Lowry Ave. for 40 years. During that time, it used tetrachloroethylene, also known as perchloroethylene (PCE, or “perc”) to clean winter coats and woolen suits. In low exposure rates, it’s thought to be harmless.
Perc, unfortunately, has a tendency to hang around and cause breathing problems. The Environmental Protect Agency classifies it as a “likely carcinogen.” The Minnesota Department of Health says perc can affect vision and delay reaction time. Studies have indicated that it may increase bladder cancer, non-Hodgkins lymphoma and multiple myeloma. Minneapolis banned the use of perc earlier this year, becoming the first city in the U.S. to do so.
When perc gets into groundwater, it can migrate from its source to other locations. It creates a vapor in the soil that can sneak its way through the foundations of homes and into the air the homeowners breathe. Tom Higgins, Superfund supervisor for the MPCA, speaking at the at the May 15 meeting of Windom Park Citizens for Action (WPCIA), said perc can enter a home through cracks in the cement, floor drains, the drain tile line and through unfinished crawl spaces. Unfortunately, you can’t smell or taste it.
The Minneapolis Community Development Agency (MCDA) began investigating the former Waldorf site in 2003 when city and county planners were looking at widening Lowry Ave. That’s when they found perc in groundwater samples. At that time, they did not find any volatile organic compounds (VOCs) in the soil. Last year, Hennepin County decided to prepare the property for handover to the City of Minneapolis for re-development. It contacted the MPCA and had the site tested.
The MPCA hired a state contractor to collect soil vapor samples from beneath the foundations of three properties closest to the site — 938 Lowry Ave. NE (Tom’s Style & Tanning), 946 Lowry Ave., a commercial property currently owned and operated for residential housing, and 952 Lowry Ave., a residential property. Perc was found in the soil and groundwater.
Investigators find perc vapor intrusion by drilling a small hole in a building’s foundation. The samples are collected in special canisters. If the sample finds more than 33 micrograms of perc per cubic meter, the department recommends taking action to mitigate the vapor intrusion. (By contrast, the regulatory occupational exposure for dry cleaner or other workers – perc was also used as a degreaser in factories – is 170,000 micrograms per cubic meter.)
Perc can be mitigated by installing a fairly simple pipe that reaches down below a building’s foundation and passively conducts the vapors out through the roof, where they disperse. This is similar to
radon mitigation.
The rental home at 946 Lowry has installed vapor mitigation equipment, but the results of its post-installation sample have not yet been received. Tom’s Style & Tanning has not committed to installing vapor mitigation. The home at 952 Lowry has been purchased by the city, which will tear it down.
There are other locations that have tested positive for perc. In 2016, the Columbia Heights City Council approved tax increment financing to help Hy-Vee clean up the old Rainbow Foods/Slumberland site at 4300 Central Ave., where dry cleaning chemicals and asbestos were found. In St. Anthony, the former Lowry Grove mobile home park is polluted with perc, and the Bremer Bank building sits upon the “hot spot.” Remediation will be performed before construction of The Village begins.
The MPCA will expand its search for perc to the Subway restaurant at 2501 Central and Expresate Beauty/Paolita’s at 2415 Central. The homeowner at 954 Lowry has been contacted, but has not yet responded to the agency’s request to test.
“We’ll keep going,” Higgins said, “until we don’t find perc anymore.”
Below: The site of the former Waldorf Cleaners is sandwiched in between a rental home and Tom’s Style & Tanning. (Photo by Cynthia Sowden)
In the graphic: The orange dotted line shows the area MPCA is testing. The tan rectangle is the former Waldorf Cleaners lot, the source of contamination. The blue-striped rental home next to the site has installed mitigation equipment. Tom’s Style & Tanning on Central Ave. and the home at 952 Lowry Ave. (in orange) have not. MPCA wants to investigate the purple buildings next.
