Minneapolis: Universal Plating Facility site

The Universal Plating property (SR0001398) consists of four separate parcels of land covering approximately 1.6 acres located at the northwest corner of the intersection of Monroe Street NE and 19th Street NE in Minneapolis. An electroplating and mechanical plating facility operated on the property from 1944 through 2009. The site is currently vacant.

Map showing the vapor intrusion area of concern for the Universal Plating site including sample results and mitigation statuses of buildings.

What's the problem?

Site investigations at the Universal Plating facility found metals and chlorinated volatile organic compounds (VOCs) in the site’s soils at concentrations that exceed the MPCA’s soil reference values for residential land use. The metals present in concentrations above the soil reference values included arsenic, cadmium, chromium, copper, cyanide, lead, nickel, selenium, and zinc and the chlorinated VOCs cis-1,2-dichloroethylene (cis-1,2-DCE), tetrachloroethylene (PCE) and trichloroethylene (TCE). The investigations also found per- and polyfluoroalkyl substances and chlorinated VOCs in groundwater underneath the site at concentrations above the regulatory limits set by the MPCA. The primary chlorinated VOC contaminants of concern are PCE and TCE, which are solvents used for metal cleaning and other industrial processes. These chemicals can end up in the groundwater because of past leaks and spills.

Groundwater contaminated with PCE and TCE can release vapors back into the soil, which can enter nearby buildings and pose health risks to the people living and working in them. This is commonly referred to as vapor intrusion. The MPCA wants to take steps to reduce or eliminate vapor intrusion where possible.

An initial soil vapor investigation conducted in 2016 indicated soil vapor levels exceeding the MPCA’s residential 33x intrusion screening value (ISV) for TCE along the southern and eastern borders of the site, prompting an off-site investigation.

Additional investigations

Soil vapor samples were collected at eight boring locations in August 2017 to evaluate the potential for soil vapor migration north, east, and west of the Site.  TCE concentrations exceeded the criteria in one of the locations adjacent to a residential area, located northeast of the Site in the right-of-way on Monroe St NE. Vapor migration was confirmed to be present both south and east of the site based on the 2016 and 2017 sampling.  Off-site investigation continued when soil vapor samples collected at ten boring locations in March 2018 revealed both TCE and PCE exceeding MPCA’s residential 33x ISVs. 

Additional sub-slab sampling in 2018-2020 conducted at seven residential properties, located north and northeast of the Site on 20th Ave, 19th Ave NE, and Monroe St NE, revealed three of the properties having PCE and/or TCE exceeding MPCA’s residential ISVs.  MPCA is planning on repairing incompetent basement slabs at all three properties, conduct additional sampling, and assess them for vapor intrusion risk. 

Health information

When chemical vapors enter buildings through the foundation, the amount in indoor air is usually not high enough to affect most people’s health. The possible health effects from breathing chlorinated VOCs depends on the amount in indoor air and how long people breathe it.

Long-term exposures to chlorinated VOCs may increase the risk of certain types of cancer based on studies in workers or animals breathing very high levels of these contaminants (thousands of times greater than what may be found at vapor intrusion sites). The Minnesota Department of Health is most concerned about women in the first trimester of pregnancy because one chlorinated VOC, TCE, may increase the risk of heart defects to the baby.

For more information regarding health and vapor intrusion, please go to the Minnesota Department of Health website.

What's being done?

Vapor intrusion investigations in the area are currently ongoing. In the coming year, the MPCA Superfund Program is continuing to conduct an investigation to define the extent and magnitude of the PCE and TCE release to soil vapor. The MPCA continues to seek access to residential and commercial properties in areas of potential concern to sample soil vapor to determine whether TCE or PCE present in the soil vapor could make its way inside, creating exposure for occupants. The MPCA needs the cooperation of property owners to compete this work.

If the sample results indicate elevated PCE or TCE vapor levels, the property and its occupants can be protected by installing a vapor mitigation system. This system is similar to a typical “radon system” installed in homes and buildings in areas where radon is naturally present in the soil. Such systems consist of a hole in the building floor with a sealed pipe that leads to a low-wattage fan in the attic or on the outside of the building. The fan pulls vapors from beneath the floor and discharges them to the atmosphere through a stack on the roof.

Visit the MPCA’s vapor intrusion webpage to learn about how these investigations take place.

Staff contact

Doree Husnik
651-757-2374
doree.husnik@state.mn.us

Michael Ginsbach
651-757-2329
michael.ginsbach@state.mn.us