ACCESS NUMBER: 30856 

STUDY TITLE: Emission Inventories of OCS Production and Development Activities in 

the Gulf of Mexico 

REPORT TITLE: User's Guide for the Breton Offshore Activities Data System (BOADS) 

for Air Quality, Interim Report, User's Guide for the Breton Offshore Activities Data 

System (BOADS) for Air Quality, Final Report, and Emission Inventories of OCS 

Production and Development Activities in the Gulf of Mexico, Final Report

CONTRACT NUMBER: 1435-01-98-CT-30856 

SPONSORING OCS REGION: Gulf of Mexico 

APPLICABLE PLANNING AREA(S): Western, Central, Eastern 

FISCAL YEAR(S) OF PROJECT FUNDING: 1998, 1999, 2000, 2001, 2002 

COMPLETION DATE OF REPORT: February 2003 

COST(S): FY 2002: $23,248 

CUMULATIVE PROJECT COST: $522,308 

PROJECT MANAGER(S): D. Coe and L. Chinkin 

AFFILIATION: Sonoma Technology, Inc. 

ADDRESS: 1360 Redwood Way, Suite C, Petaluma, California 94954 

PRINCIPAL INVESTIGATOR(S): D. Coe, L. Chinkin, M. Yocke 

KEY WORDS: Breton National Wildlife Area; outer continental shelf; emission 

inventories; Gulf of Mexico 

BACKGROUND: The region east of the Mississippi Delta contains the Breton National 

Wildlife Area (BNWA), which is protected under the Clean Air Act as a Class I air quality 

area. Air pollutant emissions from sources within 100 km of all Class I areas are 

regulated to prevent significant deterioration of air quality (through the prevention of 

significant deterioration [PSD] permitting process). For regulatory purposes, significant 

air quality deterioration is defined as an increase in an air pollutant's concentration 

(determined through air quality modeling) that exceeds an increment defined for each 

pollutant (sulfur dioxide [SO2], nitrogen dioxide [NO2]). A large number of oil and gas 

producing platforms, numerous onshore industrial sources, and several urbanized areas 

are located within 100 km of the BNWA. 

OBJECTIVES: (1) To provide technical support for the development of the BNWA 

current year OCS emission inventory; (2) to estimate historical OCS gulf-wide emissions 
ACCESS NUMBER: 30856 

for 1977 and 1988 for primary air pollutants (carbon monoxide [CO], oxides of nitrogen 

[NOx], sulfur oxides [SOx], total suspended particulates [TSP], particulate matter less 

than 10 microns [PM10], particulate matter less than 2.5 microns [PM2.5], total 

hydrocarbons [THC], and volatile organic compounds [VOC]); (3) to spatially resolve 

area and mobile sources to the grid-cell level, and point sources to specific coordinates; 

and (4) to develop computer software tools to assist the MMS in collecting and 

managing the OCS emission inventory in the future. 

DESCRIPTION: Historical inventories for the entire Gulf of Mexico were prepared for 

1977 and 1988 for oil and gas platform sources (e.g., flares and storage tanks), 

platform-associated sources (e.g., crew and supply boats), pipeline construction 

equipment, and exploration and drilling equipment. A current-year (2000) emission 

inventory was compiled from monthly surveys of platform operators for approximately 

510 facilities within 100 km of the BNWA. The inventory covered platform equipment 

and processes for surveyed facilities. Specialized data collection software was 

developed (the Breton Offshore Activities Data System for Air Quality [BOADS]) for use 

by MMS to collect and perform end-user QA/QC of the current-year emissions activity 

data. The BOADS software incorporated automated QA/QC including checks of (1) 

parameter ranges and magnitudes by source categories and (2) data formats and units 

to ensure data integrity. A relational Oracle-based DBMS was developed and delivered 

to the MMS that facilitates data input, rapid data access, automated data reports, and 

efficient data queries. The DBMS also computes and provides error warnings, range 

checks, and outlier flags. 

SIGNIFICANT CONCLUSIONS: No single source category is responsible for most of 

the emissions in the OCS. Overall, platform source emissions are greater than 

platform-related mobile source emissions. Among platform sources, platform 

equipment (e.g., engines, turbines, and boilers) are the predominant source of 

combustion-related emissions (e.g., NOx, CO, and PM); venting is the predominant 

source of THC and VOC, followed closely by glycol dehydrator units. Flares are the 

predominant source of SOx. Among mobile sources, crew and supply boats are the 

single largest source category of all pollutants. There are no consistent trends among 

pollutants in the historical emissions estimates. 

STUDY RESULTS: Oil and gas development and production are subject to economic 

cycles and technological limitations. Historical activity data compiled in this study 

reveals several observable trends: (1) within 100 km of the BNWA the number of 

platforms approximately doubled from 1990 to 2000; (2) the average platform depth was 

relatively unchanged at approximately 100 feet during the period from 1977 to 1990, but 

the average depth more than doubled after 1998 through the current year (since more 

energy is needed to construct and drill in deeper waters, more emissions are 

generated); and (3) while the number of wells drilled per year is decreasing due to 

better detection equipment and past exploration, the depth of wells drilled is increasing 

over time.
ACCESS NUMBER: 30856 

Thus, from 1977 to 1990, the amount of gas released to vent or flare equipment 

declined, but the amount released after 1990 increased in concert with increasing 

production levels (gulf-wide oil production has almost doubled since 1990). Emissions 

from diesel engines also reflect a doubling of diesel engine use from 1990 to 2000. A 

reduction in flaring activity from 1977 to 1990 was also noted. As the amount of flaring 

decreases, the emissions from other platform equipment contribute a greater share of 

the inventory. 

STUDY PRODUCTS: Coe, D.L., C.A. Gorin, L.R. Chinkin, M. Yocke, and D. Scalfano. 

2002. Emission Inventories of OCS Production and Development Activities in the Gulf of 

Mexico. Prepared by Sonoma Technology, Inc., ENVIRON International, Inc., and 

Northlake Engineers and Surveyors, Inc. OCS Study MMS 2002-073. U.S. Department 

of the Interior, Minerals Management Service, Gulf of Mexico OCS region, New 

Orleans, LA. 190 pp. 

Coe, D.L., D.J. Ladner, J.D. Prouty, L.R. Chinkin, M. Yocke, and D. Scalfano. 2000. 

User’s Guide for the Breton Offshore Activities Data System (BOADS) for Air Quality. 

Prepared for Minerals Management Service under MMS Contract 1435-01-98-CT30856 by Sonoma Technology, Inc., Petaluma, CA, ENVIRON International, Inc., 

Novato, CA, and Northlake Engineers and Surveyors, Inc., Mandeville, LA, OCS Study 

MMS 2000-081 78 pp. 

SOFTWARE PRODUCTS: 

BOADS: Breton Offshore Activities Data System for Air Quality [BOADS]) for use by 

MMS to collect and perform end-user QA/QC of the current-year emissions activity data. 

DBMS: Relational Oracle-based data base management system developed to facilitate 

data input, rapid data access, automated data reports, and efficient data queries.