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Notice of Public Comment Period
Proposed Decision to Renew Existing Exemption to Hazardous Waste Land Disposal Restrictions
Occidental Chemical Corporation, Wichita, Kansas
This public notice is issued by the U.S. Environmental Protection Agency (EPA), Region 7. EPA 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 and Recovery Act (RCRA). This existing exemption applies to the operation of five hazardous waste disposal wells at the Occidental Chemical Corporation plant located at 6200 S. Ridge Road, Wichita, Kansas. EPA is seeking written comments regarding this proposed decision.
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 injected fluids will not migrate vertically or laterally out of the injection zone within 10,000 years, or will no longer be hazardous due to natural processes before migrating out of the injection zone or into an underground source of drinking water.
Occidental operates six Class I hazardous waste injection wells at the Wichita plant site to dispose of on-site wastewater consisting primarily of constituents from the production of organic chemicals used in the manufacturing of polymers and detergents, along with stormwater runoff. Five of these deep wells are authorized to inject hazardous waste under an existing LDR exemption approved by EPA on August 7, 1990, to the former owner, Vulcan Chemicals. In 1990, Vulcan Chemicals demonstrated to EPA’s satisfaction that there would be no migration of hazardous constituents from the injection zone into an underground source of drinking water. The newer sixth well operates under a separate LDR exemption that was approved by EPA on May 2, 2007.
The original computer modeling done for the EPA-approved 1990 no-migration demonstration determined the boundary of the underground waste plume 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 before December 31, 2007 to update and support renewal of the existing LDR exemption for the five injection wells. Occidental submitted a revised no-migration petition to EPA on November 29, 2007.
To support their revised no-migration petition, Occidental used mathematical models to predict fluid flow in various settings and show 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. The proposed decision by EPA Region 7 to renew the existing LDR exemption is based on a detailed technical review of the revised no-migration petition and its supporting documents, and consultation with the Kansas Department of Health and Environment and EPA Region 6, based in Dallas.
HOW TO PROVIDE COMMENTS: Copies of the petition application, supporting documentation and Administrative Record, which includes all relevant documents and correspondence for this petition action, are available for review from 8 a.m. to 5 p.m. at the South Central District Office of the Kansas Department of Health and Environment, 130 S. Market, Sixth Floor, Wichita, KS 67202; and the Regional Records Center, EPA Region 7, 901 N. 5th Street, Kansas City, KS 66101.
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. 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 Street, Kansas City, KS 66101. Copies of a detailed fact sheet describing EPA's basis for its proposed decision can be requested from Patrick Costello at the mailing address above, by phone (toll-free) at 1-800-223-0425, or by e-mail at costello.pat@epa.gov. A final decision to approve or deny renewal of the existing LDR exemption for the five injection wells will be made after the close of the public comment period. EPA Region 7 will notify each person who submitted written comments of the final decision. The final decision will be published in the Federal Register.
EPA will also hold a formal public hearing if it is determined that there is a significant degree of public interest in the no-migration petition, based on requests. 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.
