Cheyenne PCE Plume Orphan Site
Date this web page was last edited: July 19, 2011
Orphan Site Description:
The Cheyenne Perchloroethylene (PCE) Plume orphan site is an area approximately 20 acres in size within a roughly 5 block by 3 block area of downtown Cheyenne, Wyoming. The site is centered 1 block directly west of the Herschler Building, 122 West 25th Street, Cheyenne and consists of a mixture of single and multi-home residential properties, government buildings, and commercial businesses. The chlorinated solvent contamination was first discovered in soil and shallow groundwater (5 to 15 feet below ground surface) following a Limited Subsurface Investigation conducted in December 2002 by ERM on behalf of the former Safeway Store located at 2512 Pioneer Ave, Cheyenne.
Wyoming Department of Environmental Quality (DEQ) Project Manager: Lily R. Barkau, Senior Project Manager, 307-777-7541, lily.barkau@wyo.gov
Public Meetings:
February 17, 2010 held at the Herschler Building, 122 West 25th Street, Cheyenne, WY
Site Investigation Update:
- October 2009: Site investigation began with the sampling of existing groundwater supply wells and sumps
- November -December 2009: The DEQ installed 17 groundwater monitoring wells and 44 permanent soil vapor sampling points throughout the study area
- January 2010: Public notice was initiated using mailings to residents within the study area and newspaper notices
- February 2010: A public meeting was held at the Herschler Building, Cheyenne on the 17th to notify residents of site investigation results
- March 2010: The DEQ began indoor air testing of potentially affected properties (43 locations)
- May 2010: Installation of indoor air mitigation systems began (12 properties)
- July 2010: The site investigation of groundwater and soil gas was expanded along the western edge of the study area, and source investigation into an abandoned underground storage tank was begun
- February - May 2011: DEQ continued indoor air testing of potentially affected properties (27 additional properites)
- February - June 2011: Installation of indoor air mitigation systems continued (10 properites)
- July 2011: Site investigation of soil gas was further expanded along the western edge of the previous expanded area as well as to the south.
Wyoming DEQ Documents
- Field Sampling Plan for Focused Site Inspection - Aug, 2001
- Phase I Environmental Site Assessment - Aug 2002
- Limited Subsurface Investigation, Safeway Store - Jan 2003
- Addendum to the Field Sampling Plan - Jan 2004
- Analytical Results Report for the Site Inspection - Apr 2004
- Cheyenne Orphan Site Sampling and Analysis Plan - Oct 5, 2009
- Change pages to the Sampling and Analysis Plan - Oct 20, 2009
- Cheyenne Orphan Site Frequently Asked Questions - Feb, 2010
- Site Update - Cheyenne Orphan Site - July, 2011
Orphan Site Maps:
- Shallow Groundwater Contour Map - Feb, 2010
- Soil Vapor and Groundwater Contamination Map - Aug, 2010
Orphan Site Fact Sheets:
- Residential Air Testing Procedures - Feb, 2010
- Residential Ventilation Procedures - Feb, 2010
- Commercial Air Testing Procedures - Feb, 2010