EMISSION INVENTORY SOURCE CATEGORY

METHOD SUMMARY

This category is used to estimate the total organic gas (TOG) emissions from petroleum gas and oil seeps. Some major seeps are located off the coast of Santa Barbara County. Other seeps occur throughout the state, primarily in those regions of oil and gas production. The most famous seep is located in Los Angeles County, the La Brea Tar Pits. A seep is an area where water and/or petroleum liquid trickles out of the ground and forms a pool, or a spot where gas escapes from the ground.

ACTIVITY DATA SOURCE: Estimates of seeps were based on several reports including: the California Department of Conservation, Division of Oil and Gas report "Onshore Oil and Gas Seeps in California," 1980, 1987; the State Lands Commission's report "California Offshore Gas, Oil and Tar Seeps" 1978; and the Santa Barbara County Air Pollution Control District's report "Area Source Methodologies" April 1992. Where there was only a qualitative description of a seep, flow rate estimations were made based on the qualitative and quantitative estimation of other seeps in the reports and engineering judgement. For example, the California Division of Oil & Gas Report stated that "several trickles" total to one gallon/day. From this description, "trickles" were assigned a value of one gallon/day or 365 gallons/year.

EMISSION FACTOR SOURCE: The emission factors for TOG in the methodology were based on the emission factor used from the California State Lands Commission, County of Santa Barbara & U.S. Army Corps of Engineer, L.A. District report entitled "Draft EIR/EIS Proposed ARCO Coal Oil Point Project Volume 1, Appendix 4 - Air Quality," 1986. Therefore, the emission factors used in this methodology apply to seeps statewide. In reality, emission factors for seeps would vary from one seep to another.

TEMPORAL DATA: For both categories, the annual, weekly, and daily activities are uniform throughout the year, seven days a week, and twenty-four hours a day.

DATE OF THE LAST UPDATE: April 1993

GROWTH PARAMETER: This category is updated each year. This is not grown.

STATEWIDE EMISSIONS SUMMARY (1991 - ANNUAL AVERAGE TONS/DAY)

CES No.	TOG	CO	NOX	SOX	PM
82206	16.48	0.00	0.00	0.00	0.00
82297	54.35	0.00	0.00	0.00	0.00
Total	70.83	0.00	0.00	0.00	0.00

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