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EPA in Wyoming


Groundwater Investigation

Map of Wyoming showing the Pavillion site Site Type: Non-NPL
City: Pavillion
County: Fremont
ZIP Code: 82523
EPA ID: WYN000802735
Congressional District: At Large

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  • Historical Site Documents: more than 800 reports, presentation, and documents related to quality assurance, monitoring well-drilling information, raw laboratory data, well sampling information, lab standard operating procedures, and lab-produced reports

Site Description

Welcome to Pavillion, Wyoming

Pavillion, Wyoming is located in Fremont County, about 20 miles northwest of Riverton. In 2003, the estimated population was 166 residents. The concern at the site is potential groundwater contamination, based on resident complaints about smells, tastes and adverse changes in water quality of their domestic wells. Community members contacted EPA in spring 2008.

The Pavillion area has approximately 80 domestic wells. The town of Pavillion provides municipal water to residents through eight groundwater wells. Private water wells just outside the town of Pavillion are used for drinking water, irrigation, and stock watering, and are completed at depths from 50 feet to 750 feet or more. Pavillion is within the Wind River Indian Reservation as described by the Northern Arapaho and Eastern Shoshone Tribes in a pending application for treatment in a similar manner as a state under the Clean Air Act. The site is located west of Boysen State Park.

In March 2009 EPA sampled 39 individual wells (37 residential wells and two municipal wells). The purpose of this sampling was to collect data to assess groundwater conditions and evaluate potential threats to human health and the environment. EPA conducted additional sampling in Pavillion in January 2010. This effort included sampling 21 domestic wells within the area of concern, two municipal wells, and sediment and water from a nearby creek. EPA has also sampled groundwater and soil from pit remediation sites, produced water, and condensate from five production wells operated by the primary natural gas operator in the area. EPA installed two monitoring wells in the Pavillion area in 2010. Data collected from these wells helps us build upon prior sampling events and further assess groundwater hydrology and contamination in the aquifer. EPA released the latest data from domestic and monitoring wells at a public meeting on November 9, 2011.

The Pavillion groundwater investigation was conducted by EPA’s regional office in Denver in collaboration with scientists from our Office of Research and Development.

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Richard Mylott
Public Affairs
U.S. Environmental Protection Agency, Region 8
1595 Wynkoop Street (OC)
Denver, CO 80202-1129
800-227-8917 ext. 312-6654 (toll free Region 8 only)

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Links to State Agencies

The following links exit the site Exit

Wyoming Department of Environmental Quality – Investigation of Water Quality Concerns Near Pavillion, WY

Wyoming Oil and Gas Conservation Commission

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Photo/Video Gallery

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Pavillion, Wyoming landscape
January 2010 sampling
January 2010 sampling
Collecting January 2010 samples
Preparing January 2010 samples

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