The Hospital Linen Superfund site is located at 740 7th Street East in St. Paul, at the intersection of 7th and Maple Street, about a mile east of downtown St. Paul. It's adjacent to both residences and commercial properties. Hospital Linen Services, a commercial laundry, operated at the site from the 1920s to the early 2000s. From the 1950s to the 1980s, the operation included industrial dry cleaning.
As part of a redevelopment project through the agency's Voluntary Investigation and Cleanup Program, tetrachloroethane (PCE) contaminated soil was uncovered after the building on the Hospital Linen Site was razed in 2005. Under the oversight of the VIC Program, soil cleanup was completed at the Site in 2008.
Also as part of the redevelopment, soil vapor samples were collected and concentrations of PCE greater than 100-times the industrial Intrusion Screening Value (ISV) were present in the samples. As a result, the Site was referred to the Site Assessment Program for follow up and was subsequently listed on the State Superfund Permanent List of Priorities in 2016.
The contamination originated at the former location of the Hospital Linen site. The extent of the vapor intrusion area needs to be further defined using groundwater monitoring wells and soil borings so that testing and mitigation, if needed, of the buildings can be undertaken.
What's the problem?
Elevated levels of PCE have been found in soil vapor at the Hospital Linen site and some nearby properties. The PCE in soil vapor does not pose a risk to people. However, under certain circumstances, soil vapor can intrude into nearby buildings and pose health risks to the people living and working in them.
Possible health effects
Vapor intrusion is chemical vapors seeping from contaminated groundwater through the soil and into buildings. The vapors can degrade indoor air, sometimes to the point of affecting human health. Recent research shows that volatile organic compounds (VOCs) entering homes as vapor may be more harmful than previously thought. As a result, the MDH has recommended lowered intrusion screening values (ISVs) for several VOCs, including PCE. Long-term inhalation exposure to PCE may cause symptoms such as impaired cognitive performance and adverse effects to the kidney, liver, and immune system. Sensitive populations including pregnant women, infants and young children, elderly people, or those with chronic diseases.
- Hospital Linen operated at this location from the 1920s to the early 2000s.
- From the 1950s to the 1980s, operations included industrial dry cleaning.
- In 2005, demolition of the on-site building led to the discovery of tetrachloroethane (PCE) contamination beneath a portion of the Site.
- Soil cleanup of PCE-contaminated soil plus a buried layer of ash was completed at the Site in 2008 with the oversight of the MPCA's VIC program.
- Pre-construction soil vapor samples collected in 2014 detected concentrations of PCE greater than 100-times the industrial Intrusion Screening Value (ISV) in the soil vapor — the Site was referred to the MPCA Site Assessment Program for follow up.
- In 2014, the MPCA contracted with Bay West to investigate the vapor intrusion in the area surrounding the Hospital Line Site.
- In 2014 and 2015, 16 residential and two commercial buildings were sampled.
- Four of these residences required mitigation systems, which were installed in 2015.
- Four additional residential homes require mitigation, which is planned for 2016-17.
- Vapor intrusion testing is planned at 32 homes and four commercial buildings in 2016-17.