The Gulf Of Mexico Air Quality Study: An Industry Perspective

Abstract

ABSTRACT Section 328 of the Clean Air Act Amendments of 1990 required the EPA to promulgate a rule establishing air pollution control requirements for Outer Continental Shelf (OCS) sources. Congress exempted Gulf of Mexico OCS sources west of 87.5 degrees longitude (near the border of Alabama and Florida) pending the results of a "three year" study conducted by the Department of Interior (DOI) - Minerals Management Service (MMS). The study required an examination of the impacts of emissions from OCS activities in such areas that fail to meet the National Ambient Air Quality Standard (NAA 0S) for either ozone or nitrogen dioxide. This paper reviews the MMS Gulf of Mexico Air Quality Study's (GMA OS) emission inventory development, historical ozone episode modeling, field sampling, and preliminary photochemical modeling results. Industry has developed a standardized spreadsheet to calculate emissions and a software package to allow operators to figure out the cost to control OCS sources for NOX and VOCS under the EPA's OCS Air Regulations (40 CFR Part 55). Cost estimates are provided for various regulatory scenarios currently being reviewed by the EPA and MMS. CONGRESSIONAL MANDATE Oil and gas exploration and production operations conducted on the OCS are regulated by the MMS, U.S. Coast Guard (USCG), Environmental Protection Agency (EPA), and the Department of Transportation (DOT). Air emission from OCS sources have historically been regulated by MMS until passage of the Clean Air Act Amendments of 1990 (CAAA)1. Title Ill, Section 328 of the CAAA - Air Pollution from OCS Activities (42 U.S.C. 7627), mandated that EPA develop regulations to control air pollution from OCS sources located offshore the States along the Pacific, Arctic and Atlantic Coasts, and along the United States Gulf Coast off the State of Florida eastward of longitude 87 degrees and 30 minutes. These regulations have been codified at 40 CFR Part 55- Outer Continental Shelf Air Regulations2. For portions of the United States Gulf Coast OCS that are adjacent to the States of Texas, Louisiana, Mississippi, and Alabama, 40 CFR Part 55 does not apply and air pollution regulatory authority remains with MMS3. This congressional exemption, for the central and western Gulf of Mexico, from EPA OCS air regulations was passed pending a MMS research study which will examine the impacts of emissions from OCS activities in such areas that fail to meet the NAAQS for either ozone (O3) or nitrogen dioxide (NOx). Since Los Angeles, California is the only NOx non-attainment area in the United States the GMAQS will focus on O3 non-attainment areas along the Gulf Coast. The primary and secondary standard for O3 is 0.120 parts per million (ppm) (or 120 parts per billion (ppb))4. An area is designated as non-attainment when one maximum hourly average O3 concentration is above 120 ppb. For the GMAQS these areas include Houston, Texas and its surrounding counties; Beaumont - Port Arthur, Texas; Baton Rouge and Lake Charles, Louisiana, with their surrounding parishes.