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.