State of California AIR RESOURCES BOARD Crystal Ballroom Hotel San Franciscan 1231 Market Street San Francisco, CA April 26, 1978 10:00 a.m. AGENDA Page 78-7-1 Consideration of Model Control Strategy for 1 Hydrogen Sulfide Emissions at The Geysers. 78-7-2 Consideration of a Proposed Model Rule for the 64 Control of Emissions of Sulfur Oxides and Oxides of Nitrogen from Steam Generators in the San Joaquin Valley Air Basin. 78-7-3 Other Business - a. Executive Session - Personnel & Litigation b. Research Proposals ITEM NO.: 78-7-1 Public Hearing to Consider a Model Control Strategy and Model Rules for the Control of Hydrogen Sulfide Emissions from Activities Associated with Electric Power Development at "The Geysers". RECOMMENDATION In view of the essentially clean nature of geothermal power and its desirability as an alternative energy source to broaden our domestic energy base and as a substitute for some fossil-fuel electric power, 1. The Air Resources Board staff recommends that the Board transmit to the Northern Sonoma and Lake County Air Pollution Control Districts the following set of performance standards for the control of H2S emissions from geothermal sources at "The Geysers": A. "Effective January 1, 1979, 1) power plant Units 3, 4, 5, 6, 11, and 12 (equipped with direct contact condensers and the iron catalyst H2S control system) shall emit at a rate of not more than 200 gm H2S per MwHr; 2) all power plant Units constructed after January 1, 1979, except Unit 12 shall emit at a rate of not more than 175 gm H2S per MwHr"; B. "Effective January 1, 1980, 1) all power plant Units constructed after January 1, 1980, except Unit 12 shall emit at a rate of not more than 100 gm H2S per MwHr; 2) H2S emissions from steam supply operations, including well drilling, cleaning, reworking, and testing, well bleeds, valves, and meters, and pipeline vents, shall not exceed 5 kilograms (kg) per 1000 Mw of electric power production (5 gm/MwHr); 3) H2S emissions for any single well shall not exceed 2.5 Kg per hour during any conditions; 4) H2S emissions associated with steam vented during power plant shutdowns or outages ("steam stacking") shall be reduced to not more than 35 percent of the H2S in the supplied steam at full power plant load within 15 minutes of shutdown or outage; 5) all power plant Units constructed before January 1, 1979 and Unit 12 (Units 1 through 12) shall reduce their total H2S emissions to not more than 75 Kg per hour during "episode alerts"; C. "Effective January 1, 1982, H2S emissions from Thermal 4 well ("Wild Well") shall be reduced to not more than 1.5 Kg per hour"; D. "Effective January 1, 1984, all power plant Units constructed before January 1, 1979 and Unit 12 (Units 1, 2, 7, 8, 9, and 10; Units 2, 4, 5, 6, 11, and 12 equipped with the iron catalyst system) shall emit at a rate of not more than 200 gm of H2S per MwHr"; E. "Effective January 1, 1986; 1) all new power plant units shall emit not more than 50 gm of H2S per MwHr; 2) H2S emissions associated with steam vented during power plant shutdowns or outages ("steam stacking") shall be reduced to not more than 10 percent of the H2S in the steam supplied at full power plant load within 15 minutes of the shutdown or outage"; F. "Effective January 1, 1990, all power plant Units completed after January 1, 1979, except for Unit 12 shall emit at a rate of not more than 50 gm of H2S per MwHr"; G. "Effective January 1, 2000, all power plant Units constructed before January 1, 1979 and Unit 12 shall emit at a rate of not more than 100 gm of H2S per"; 2. The Air Resources Board staff recommends that the Board request both the Lake and Northern Sonoma County Air Pollution Control Districts to adopt these performance standards or similar identical performance standards and schedules approved by the ARB and enforce them. 3. The Air Resources Board staff recommends that the Board request both the Lake and Northern Sonoma Air Pollution Control Districts to adopt procedures and requirements for the review and evaluation of geothermal projects which direct that: A. developmental geothermal wells and power plants be considered as a single project for an authority or permit to construct and/or operate, and B. in evaluating a geothermal project for an authority or permit to construct and/or operate that all elements of the project meet the requisite performance standards and that the H2S emissions from the project will not cause a violation of the California ambient air quality standard for H2S (0.03 ppm for 1 hour) where and when receptors are likely to be present. 4. The Air Resources Board staff recommends that the Board request that both Lake and Sonoma counties; A. add a "geothermal element" to their County General Plans setting forth, (1) the criteria for identifying land uses which are incompatible with geothermal developments, and (2) those areas where geothermal activities are permitted such that neighboring areas with receptors will not suffer adverse H2S air quality impacts; B. zone such land appropriately with respect to the "geothermal element" and enforce the land uses accordingly. SUMMARY California possesses much of the nation's known high temperature geothermal resources. Geothermal energy is attractive because it does not present some of the environmental hazards associated with fossil fuel and nuclear power. However, there are some environmental problems specific to geothermal developments and the greatest of these is air pollution by hydrogen sulfide (H2S). In September 1977, the staff presented the Board a report (77-21-3, September 30, 1977) discussing the nature of geothermal energy, its quantity and distribution in California, the air pollution problems resulting from its development, the H2S control technology in use and under development, and the current local regulations then used to meet these problems. After receiving and discussing this report, the Board directed the staff to analyze the problem further and to prepare a plan for controlling air pollution associated with the use of geothermal energy at "The Geysers" in Sonoma and Lake Counties. The staff has sought additional information concerning air pollution from geothermal operations and has conferred with the principal geothermal operators and other knowledgeable sources to obtain as much current data as possible concerning H2S production, emissions, and up-to-date information on proposed developments and control plans. The major known geothermal air pollution problem is from the use of geothermal steam at "The Geysers" to generate electrical energy and the associated releases of H2S emissions. "The Geysers" is the most rapidly developing geothermal resource in California. The staff summarized the available data on H2S emissions and sources, current air quality and H2S controls and conducted a workshop on February 17, 1978; various members of the industry, principal state and local agencies, and the public concerned with geothermal energy at "The Geysers" participated. Information from the workshop has been incorporated into an analysis of the possible growth of electric power at "The Geysers" and the H2S control strategy necessary to attain and maintain the state ambient air quality standard under the projected development. The proposed strategy was determined by: a) relating current H2S emissions to recently monitored atmospheric H2S concentrations; b) estimating the rate of development of electric power at "The Geysers"; c) using the range of measured concentrations of H2S in the steam to forecast future H2S emissions at "The Geysers"; d) assessing the future technological capability to reduce H2S emissions and the expected availability of the control technologies; and e) estimating the degree of control which needs to be met by future developments. The resulting strategy is a set of performance standards and schedule for their application that should allow 4000 Mw of electric power to be generated at "The Geysers" by the year 2000 while attaining and maintaining the H2S air quality standard. The strategy is based upon a direct relationship between ambient H2S levels and H2S emissions and upon the assumption that the future expansion will be essentially a progressive outward growth from the present locus of development. This analysis assumes that incidents where the air quality standard has been exceeded were the result of the production and use of geothermal steam and were not the result of the production and use of the geothermal steam and were not the result of local natural sources of H2S. The present information on emissions and control of H2S indicates that although the air quality standard is exceeded at "The Geysers", technology now available or under development can achieve major reductions in H2S emissions. The analysis of this information supports the following conclusions: 1. At the level of present development (502 Mw), emissions from geothermal operations at "The Geysers" cause the H2S standard to be exceeded by a factor of nearly 3. 2. A high degree of H2S control is possible in new generating units designed to minimize H2S emissions and an even higher degree of control will be possible by 1985. 3. Existing uncontrolled units can be partially controlled during critical meteorological conditions by cost effective means by December 31, 1978. 4. Existing units can be continuously controlled by upstream removal of H2S by 1984. 5. Despite wide application of highly efficient H2S control technology it is probable that some detectable odor of H2S will exist from time to time in the vicinity of wells and power plants. Development of geothermal power cannot be made compatible with all uses of neighboring land. ITEM NO.: 78-7-2 Public Hearing to Consider a Proposed Model Rule to Control the Emissions of Sulfur Oxides and Oxides of Nitrogen from Steam Generators in the San Joaquin Valley Air Basin. RECOMMENDATION Approve the model rule for the control of emissions of sulfur oxides (SOx) and oxides of nitrogen (NOx) from steam generators in the San Joaquin Valley Air Basin. SUMMARY Thermally enhanced oil recovery operations result in the emission of about 250 tons per day of sulfur oxides and about 110 tons per day of oxides of nitrogen in the Kern County portion of the San Joaquin Valley Air Basin. These emissions are partially converted to sulfate and nitrate aerosols that are not readily dispersed during stagnant wintertime atmospheric conditions. The California 24-hour standards for sulfur dioxide and sulfates have been exceeded by as much as 100 percent in the Kern County portion of the Basin. In addition, the California standards for total suspended particulate and oxidant have been exceeded by even greater margins. A model rule is proposed which would 1) limit the concentration of sulfur compounds in emissions from existing steam generators to 200 parts per million; 2) limit the concentration of sulfur compounds in emissions from new steam generators to 60 parts per million; 3) limit the concentration of oxides of nitrogen from existing steam generators to 150 parts per million; 4) limit the concentration of oxides of nitrogen from new steam generators to 100 parts per million; 5) require existing steam generators to be in compliance by September 1, 1980 and new steam generators to be in compliance at the time of installation; and 6) allow averaging of emissions from existing steam generators that are within one quarter mile of another existing steam generator when determining compliance. The rule would reduce current emissions of SOx and NOx to levels where their respective ambient standards should not be exceeded and move toward attainment of the State ambient standards for oxidant, total suspended particulate, and visibility.