Highway 7 and Wooddale Avenue Vapor Intrusion Investigation

 
Site Contact:
Sonia R. Vega
OSC

(vega.sonia@epa.gov)

Site Location:
6528 W. Lake Street
Suite F
St. Louis Park, MN 55416
response.epa.gov/highway7andwooddaleavenue

The EPA Command Post is located at 6528 W. Lake Street, Suite F (enter next to Monte’s Barbers and follow hallway to Suite F). The phone number for the Command Post is 952-922-2375.

The US EPA, MPCA, MDH, and the City of St. Louis Park (partnering agencies) are conducting an investigation of vapor intrusion (PCE and TCE) at an estimated 300 properties in two areas (see attached site map) near Highway 7 and Wooddale Ave. in St Louis Park, Minnesota. In June 2007, the MPCA requested US EPA assistance in the investigation after MPCA found PCE and TCE in soil vapor collected in the residential neighborhood at concentrations up to 2,680 and 833 ppb respectively. PCE in groundwater was detected at concentrations up to 13,000 ppb. Benzene and 1,2,4-trimethylbenzene were also detected at the site.

On November 30, 2007, the partnering agencies mailed letters to affected property owners informing them of the investigation and requesting access to their property (see attached letter). On December 4, 2007, US EPA issued a news release (attached) announcing the investigation and held a press availability session with the partnering agencies. Public meetings to discuss the study and obtain access agreements were held on December 13 and 15, 2007 at the St. Louis Park Recreation Center (an online replay of the meeting is available at http://www.stlouispark.org). US EPA and its partners continued to sign up property owners for the study throughout late December and early January.

US EPA's Environmental Response Team (ERT) installed sample probes at properties participating in the study during the weeks of January 14 and January 21, 2008 (see link to 1/14/08 news clip for more information). On January 28, 2008, EPA began collecting sub-slab air samples and analyzing them in their mobile laboratory, the Trace Atmospheric Gas Analyzer (TAGA) bus, that was mobilized to St. Louis Park for this study (see TAGA video and links to 1/28/08 news clips for more information). Indoor air samples were collected in early February, 2008 at properties with sub-slab levels of PCE and/or TCE above screening levels established by MDH.

Based on the results of the sampling described above, EPA and its partners expanded the study area as indicated in the site map above. Sampling in the expanded area was conducted by ERT in mid-March, 2008.

Also in mid-March, EPA began designing and installing vapor abatement systems for residences with elevated TCE and/or PCE concentrations in the indoor air and/or exceedances to the sub slab screening levels at the property. EPA is repeating the sub-slab and indoor air sampling at these residences 30 and 90 days after abatement system installation to ensure proper performance of the system.

A public meeting was held on March 19, 2008 at the St. Louis Park Recreation Center to update the community on the project (an online replay of the meeting is available at http://www.stlouispark.org).

Concurrent with property sampling and abatement system installation, EPA is conducting an investigation to determine the extent of groundwater contamination and to identify the party responsible for the contamination. Toward that end, soil gas samples were collected at select outdoor locations in both Area A and B during the week of April 28, 2008 (see images) to augment the sub-slab air sample data previously conducted for this Site. EPA will begin installing additional groundwater wells at Center Park (Zarthan & Oxford) and along the City of St. Louis Park Right-of-Way at the corner of Dakota & Oxford on May 19, 2008.


For additional information, visit the Pollution Report (POLREPS) section.