Cheyenne PCE Plume

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:   

Jaymee Binion, Project Manager, 307-777-7541, jaymee.binion@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 properties)
  • February - June 2011: Installation of indoor air mitigation systems continued (10 properties)
  • 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.
  • November 2011:  Completion of indoor air testing of potentially affected properties (4 additional properties)
  • March 2012:  Site Investigation Report completed.  Initial site investigation activities completed.  DEQ begins evaluation for additional investigation requirements and/or remediation of groundwater.
  • Spring 2017: Anticipate development of a Remedial Alternatives Evaluation, including additional data collection as needed

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