Notice of Final NPDES General Permit for New and Existing Sources and New Dischargers in the Offshore Subcategory of the Oil and Gas Extraction Category for the Western Portion of the Outer Continental Shelf of the Gulf of Mexico (GMG290000)

SUMMARY:

EPA Region 6 today issues a final National Pollutant Discharge Elimination System (NPDES) general permit for the Western Portion of the Outer Continental Shelf of the Gulf of Mexico (No. GMG290000). The general permit authorizes discharges from new sources, existing sources, and new dischargers in the Offshore Subcategory of the Oil and Gas Extraction Point Source Category (40 CFR part 435, subpart A). The reissued permit will become effective November 8, 2004. The existing permit published in the Federal Register, at 64 FR 19156 on April 19, 1999 and modified on January 22, 2001 (66 FR 6850), authorizes discharges from exploration, development, and production facilities located in and discharging to Federal waters of the Gulf of Mexico seaward of the outer boundary of the territorial seas offshore of Louisiana and Texas. Today's action reissues the permit which expired on November 3, 2003.

A copy of the Region's responses to comments and the final permit may be obtained from the EPA Region 6 Internet site: http://www.epa.gov/earth1r6/6wq/6wq.htm.

A Record of Decision which completes the Environmental Assessment process required by the National Environmental Policy Act is also available at the above Internet address.

FOR FURTHER INFORMATION CONTACT:

Ms. Diane Smith, EPA Region 6, 1445 Ross Avenue, Dallas, Texas 75202, Telephone: (214) 665 7191, or via e-mail to the following address: smith.diane@epa.gov.

SUPPLEMENTARY INFORMATION:

Regulated Entities. Entities potentially regulated by this action are those which operate offshore oil and gas extraction facilities located in the Outer Continental Shelf Offshore of Louisiana and Texas.

This table lists the types of entities that EPA is now aware could potentially be regulated by this action. Other types of entities not listed in the table could also be regulated. To determine whether your (facility, company, business, organization, etc.) is regulated by this action, you should carefully examine the applicability criteria in Part I. Section A.1. of the general permit. If you have questions regarding the applicability of this action to a particular entity, consult the person listed in the preceding FOR FURTHER INFORMATION CONTACT section.

Pursuant to section 402 of the Clean Water Act (CWA), 33 U.S.C. section 1342, EPA proposed and solicited comments on NPDES general permit GMG290000 at 69 FR 39478 (June 30, 2004). Notice of this proposed permit modification was also published in the New Orleans Times Picayune, Lafayette Daily Advertiser, and Houston Chronicle on July 2, 2004. The comment period closed on July 30, 2004.

Region 6 received comments from the Offshore Operators Committee, Petroleum Equipment Suppliers Association, Cognis Oilfield Chemicals, Minerals Management Service, Murphy Exploration and Development Company, and W&T Offshore, Inc.

EPA Region 6 has considered all comments received. In response to those comments the following changes were made to the proposed permit. The effective date was changed to be 30 days after the publication date in the Federal Register. Produced water monitoring requirements are included for facilities located in the hypoxic zone. The analytical method for analysis of cadmium in barite is included. A new allowance is included for blending of compliant synthetic base fluids in drilling fluids. The discharge of hydrate control fluids was added to the list of miscellaneous discharges which are authorized. The toxicity limit for sub-sea fluids was decreased from 200 mg/l to 50 mg/l. Non-lethal effects are required to be reported for chronic toxicity testing and the dilution series required for testing was clarified. A number of minor typographical errors and clarifications were also made to the permit's language.