Fact Sheet
September 2015
Public Comment Period for Statement of Basis and Proposed Final Remedy for Cleanup, West Sidney Gas Plant, Sidney, Nebraska
INTRODUCTION
The U.S. Environmental Protection Agency (EPA) Region 7 invites the public to comment on the Resource Conservation and Recovery Act (RCRA) Statement of Basis and the proposed final remedy for the Former West Sidney Gas Plant (WSGP) facility (EPA ID # NER000008276) in Sidney, Neb. The comment period runs from August 27 through September 25, 2015.
Written comments should be mailed or emailed no later than September 25, 2015, and should be sent to:
Robert Aston
EPA Region 7 (AWMD/ RCAP)
11201 Renner Blvd.
Lenexa, KS 66219
Phone: 913-551-7329
Email: aston.robert@epa.gov
BACKGROUND
Marathon Oil Co. began operating the WSGP as a natural gas processing plant in 1954. Processes included separation of water and liquid hydrocarbons from natural gas wells. The water and liquid hydrocarbons had to be removed before the natural gas could be used.
Marathon Oil Co. operated surface impoundments at the facility from 1964 to 1982. Wastes placed in the surface impoundments include waste products that were created during the removal of the water and liquid hydrocarbons from the raw natural gas. In 1997, Marathon excavated these surface impoundments and treated the soils on-site. Currently no structures exist from the original gas processing facility and the site is used to raise agricultural crops using natural precipitation.
ENVIRONMENTAL CONDITIONS AT WSGP
The historical waste handling practices resulted in contamination of groundwater and subsurface soils in the area. In September 2003, EPA issued a unilateral order to Marathon to investigate the extent of contamination. During these investigations, a groundwater contaminant plume was identified along with an oily layer, known as a light non-aqueous phase liquid layer (LNAPL), on top of the groundwater. In 2010, EPA negotiated an Administrative Order on Consent with Marathon to propose and implement a plan for cleanup of the WSGP.
PROPOSED FINAL REMEDY
EPA is proposing the following corrective measures to address contamination at the WSGP:
WSGP Groundwater Contamination
- Implement a monitored natural attenuation (MNA) program to remediate groundwater contamination on- and off-site until concentrations of all groundwater contaminants are below final cleanup standards.
- Implement a groundwater monitoring program to document contaminant plume containment and reduction in contaminant concentrations.
- Routinely sample an adjacent residential well and any new residential wells, which could be potentially impacted by site related contaminants.
- As a contingency, Marathon Oil Co. may implement non-aqueous phase liquid recovery in the event that LNAPL thicknesses increase within the contaminant plume.
Institutional Controls
- Implement and maintain institutional controls to restrict property use to agricultural crop production; prohibit the installation of groundwater wells for uses other than environmental investigation and cleanup; and prevent disturbance of subsurface soils in the disposal pit area.
- Marathon Oil Co. will routinely monitor the surrounding area for newly installed wells at residential construction.
FOR MORE INFORMATION
EPA encourages the public to review the Administrative Record file and provide comments. Comments should be submitted by September 25 2015.
Guidelines for Commenting:- Explain your views.
- Tell us if you support or disagree with the recommendation. Please be specific.
- Provide alternatives.
The Administrative Record file is available at the following locations during normal business hours:
EPA Region 7 Records Center
11201 Renner Blvd.
Lenexa, KS 66219
Phone: 913-551-7166
Sidney Public Library
1112 12th Street
Sidney, NE 69162
Phone: 308-254-3110
A public availability session has not been scheduled, but will be held if a written request for a session is made to the EPA contact listed on Page 1 within the first 10 days of the comment period. The written request must state the nature of the issues to be raised at the public availability session. EPA will evaluate any request and hold a public availability session if EPA determines that a session will contribute to the decision-making process by clarifying significant issues affecting the remedy.
EPA will make the final remedy selection only after the public comment period ends and all comments are reviewed and responded to. EPA may modify the remedy based on any new information and comments from the public.
Individuals may write to the EPA contact below to join the mailing list. Joining the mailing list will allow an individual to receive any updated information directly. If you have questions or want to receive further information about the mailing list, please contact:
Brendan Corazzin
Community Engagement Specialist
EPA Region 7
11201 Renner Blvd.
Lenexa, KS 66219
Phone: 913-551-7429
Toll-free: 1-800-223-0425