Reissuance of the NPDES General Permit for the Territorial Seas Off Texas
The Regional Administrator of EPA Region 6 has issued the final National Pollutant Discharge Elimination System (NPDES) “General Permit for the Territorial Seas off Texas” (No. TXG260000) for discharges from existing and new dischargers and New Sources in the Offshore Subcategory of the Oil and Gas Extraction Point Source Category (40 CFR part 435, subpart A) as authorized by section 402 of the Clean Water Act, 33 U.S.C. 1342. The permit supersedes the previous general permit (TX0085651) issued on September 15, 1983 and published in the Federal Register at 48 FR 41494. That permit authorized discharges from exploration, development, and production facilities located in and discharging to the territorial seas off Texas. Through this reissuance, EPA includes current technology and water quality based effluent limitations consistent with National Effluent Limitations Guidelines, Federal Ocean Discharge Criteria, and State Water Quality Standards.
EPA made the following changes to the proposed permit. Ambient density stratification data were examined and the critical dilutions required for the produced water toxicity limits were recalculated. The proposed 48-hour acute toxicity limit was replaced with a seven day chronic toxicity limit. An exemption for toxicity caused by total dissolved solids was included for the 24-hour acute toxicity limits. The permit allows collection of a single grab sample for toxicity testing. The State lease and well numbers are required to be reported on the notice of intent to be covered. Unmeasurable de-minimis discharges of drilling fluids such as wind blown splatters from pipe racks are authorized. A number of minor typographical changes and clarifications were also made to the permit’s language.
A copy of the Region’s responses to comments and the final permit may be obtained from the EPA Region 6 Internet site: