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Fact Sheet
July 2008
Proposed Decision to Renew Existing Exemption to Hazardous Waste Land Disposal Restrictions, Occidental Chemical Corporation, Wichita, Kansas
INTRODUCTION
The U.S. Environmental Protection Agency (EPA), Region 7, proposes to renew an existing exemption from the Land Disposal Restrictions (LDR) of the Hazardous and Solid Waste Amendments of 1984 (HSWA) to the Resource Conservation Recovery Act (RCRA).
The existing exemption applies to the operation of five hazardous waste disposal wells at the Occidental Chemical Corporation plant located at 6200 South Ridge Road, Wichita, Kansas.
Background
Under Title 40 of the Code of Federal Regulations (40 CFR §148.20), any person seeking an exemption from the LDR in order to dispose of restricted hazardous waste via deep-well injection must submit a petition to EPA demonstrating to a reasonable degree of certainty that there will be no migration of hazardous constituents from the injection zone for as long as the waste remains hazardous. The goal of this regulation is to prevent contamination of underground sources of drinking water.
Occidental operates six Class I hazardous waste disposal wells at the Wichita plant site. Five of the injection wells (No. 3, 4, 7, 8 and 9) are authorized to dispose of hazardous waste under an existing LDR exemption that was approved by EPA on August 7, 1990, to the former owner, Vulcan Chemicals. The newer sixth well (No. 10) operates under a separate LDR exemption that was approved by EPA on May 2, 2007.
The original computer modeling designed to determine the boundary of the underground waste plume was initially based on an estimated 17-year operational life of the five injection wells, that is, through 2007. Given that Occidental is continuing injection operations past 2007, EPA therefore requested that Occidental submit a new petition and supporting documentation to update and support renewal of the existing LDR exemption for the five injection wells before December 31, 2007. Occidental submitted a revised petition to EPA on November 29, 2007.
Mathematical models predicting fluid flow under various geologic conditions were used to demonstrate physical containment of the waste within the injection zone. The modeling submitted to EPA by Occidental has projected maximum lateral and vertical waste movement to be confined to the injection zone for a period of 10,000 years, which satisfies the no-migration demonstration requirements at 40 CFR 148.20.
Development of the proposed decision by EPA Region 7 is based on a detailed technical review of the revised petition and its supporting documents, and consultation with the Kansas Department of Health and Environment and EPA Region 6.
Opportunity for Public Comment
EPA is soliciting written comments on the Agency's proposed decision to approve this petition. The public comment period opens July 21, 2008, and closes September 3, 2008.
Copies of the petition application, supporting documentation, and Administrative Record are available for review between 8 a.m. and 5 p.m. at the following locations:
Kansas Department of Health and Environment
South Central District Office
130 S. Market, Sixth Floor
Wichita, KS 67202
Regional Records Center
EPA Region 7
901 N. 5th Street
Kansas City, KS 66101
If it is determined that there is a significant degree of public interest, based on requests, EPA will hold a formal public hearing. Any request for a public hearing must be in writing and must state the nature of the issues that the requestor proposes to raise at the hearing.
Where to Send Comments
All written comments regarding the proposed decision must be postmarked by September 3, 2008, and sent to:
Patrick Costello
EPA Region 7
Drinking Water Management Branch
901 N. 5th St.
Kansas City, KS 66101
A final decision to approve or deny the petition will be made after the close of the public comment period, and published in the Federal Register. EPA Region 7 will notify each person who submitted written comments of the final exemption decision.
Additional Information
For more information, or to request copies of a more detailed fact sheet describing EPA's basis for its proposed decision, please contact Patrick Costello at the mailing address above, or by phone or e-mail, as follows:
Toll-free: (800) 223-0425
E-mail: costello.pat@epa.gov
