State of California
AIR RESOURCES BOARD
The Beverly Garland Motor Lodge
Ballroom
1780 Tribute Road
Sacramento, CA
March 25, 1981
10:00 a.m.
AGENDA
Page
81-4-1 Public Meeting to Discuss a Proposed Air 001
Resources Board Policy Regarding Incineration
as an Acceptable Technology for PCB Disposal.
81-4-2 CONTINUATION OF Public Meeting to Consider 176
Suggested Control Measure for the Control of
Oxides of Nitrogen Emissions from Electric
Utility Gas Turbines.
81-4-3 Other Business
a. Executive Session
Personnel
Litigation
b. Research Proposals
c. Delegations to Executive Officer
- Request for Delegation of Authority to Adopt
Amendments to Motorcycle Emission Regulations (13
CAC Section 1958(f)).
ITEM NO.: 81-4-1
Public Meeting to Discuss a Proposed Air Resources Board Policy
Regarding Incineration as an Acceptable Technology for PCB
Disposal.
SUMMARY
Polychlorinated biphenyls (PCBs) are a class of chlorinated
hydrocarbon compounds which have been manufactured for
approximately 50 years in this country for use chiefly in the
electrical industry. In only the last 10 years, however, has
public attention focused on the human toxicity of PCBs. PCBs are
moderately toxic on an acute basis and fairly low levels of
chronic exposure can cause symptoms of intoxication. Some of the
suspected toxic effects produced by exposure to PCBs and their
incomplete combustion by-products are liver injury, teratogenic
effects, tumors, and reduced immunity to diseases.
Approximately 1 billion pounds of PCBs are in use or in storage
nationwide. In California, it is expected that over 1 million
pounds per year of PCBs will require disposal over the next ten
years. PCBs are already a universal atmospheric contaminant,
having a global distribution over even the remote ocean islands.
Vaporization of PCBs which were not kept in air tight containers
has resulted in ambient concentrations of PCBs as high as 50
nanograms per cubic meter. Increases in ambient concentrations
are anticipated to occur as large quantities of PCBs are removed
from service and stored. Both atmospheric and aquatic transports
of PCBs contribute to significant concentrations of PCBs in food.
Eggs, cow's mild, fish, and poultry tested contain traces of
PCBs, in the parts per million (ppm) range. A recent study in
Michigan showed that human mother's mil contains 0.3 to 5.1 ppm
PCBs; the Federal FDA limit for cow's mil is only 1.5 ppm.
Because the practice of toxic waste burial in the United States
has been fraught with long term containment problems, EPA has
promulgated regulations which prohibit the disposal, in
landfills, of PCBs at concentrations above 500 ppm. since the
ban on burying high concentration of PCBs, there has been
considerable interest in the destruction of PCBs through various
chemical treatment techniques and combustion.
Because the combustion of PCBs creates a potential air pollution
problem associated with incomplete combustion, or the formation
of toxic by-products of combustion, the ARB staff has been
developing criteria for PCB incineration devices. At present,
proper cement kiln incineration appears to the staff to be the
best way of eliminating the threat which PCBs now pose to our
air, land, and water environments. The staff is recommending
that the Board approve criteria which the staff has developed for
the combustion of PCBs in cement kilns. Following the criteria
proposed by the ARB staff, PCBs can be destroyed in cement kilns
with such high efficiency that the maximum ambient air
concentrations of PCBs and PCB by-products are estimated to be
significantly below the concentrations to which people are
routinely exposed.
Cement kilns operate at very high temperatures (1200-1700øC) and
with relatively long residence times for the combustion process
(1.7 to 10.0 seconds). They have been shown in test burns to
destroy PCBs o the limits of analytical detectability (99.99998
percent destruction). Many cement kilns in California are
located in remote areas with low population densities. Cement
kilns also have an intrinsic safety factor; the conditions for
making cement are such that the kiln must maintain operational
temperatures, dwell, and O2 parameters which far exceed those
required for PCB destruction. The basic criteria which the staff
believes should be met to ensure a safe PCB incineration
operation at a cement kiln are:
1. The kiln operator is required to collect baseline data,
including PCB blood levels of employees and background
ambient monitoring before any test burn;
2. A comprehensive kiln emission measurement evaluation (source
test) must be performed during the test burn using the fuel
(or fuels) to be used during the commercial burns. Using
methods approved by the APCO, this test must analyze for
PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), and
polychlorinated dibenzo-p-furans (PCDFs);
3. The kiln must be equipped with safety features including:
- failsafe PCB feed shut off system controlled by kiln
parameters;
- PCB storage and unloading facilities must be designed
to avoid spills and accidents; and
4. PCB fluids may not be mixed or significantly contaminated
with other hazardous chemicals.
The ARB staff has performed an assessment of health risks from
any airborne PCBs and their toxic by-products resulting from
cement kiln incineration of PCBs. Due to limits of anlaysis, it
cannot be predicted that absolutely no PCBs, PCDDs (dioxins), or
PCDFs (furans), will be emitted. However, using worst-case
analyses, predicted emission levels are extra-ordinarily small.
The predicted values for PCBs range from 0.013 to 0.45 nanograms
per cubic meter (ng/m3) over 24 hours, which are values well
below background (0.5 to 14 ng/m3) and home 39 to 620 ng/m3)
levels. The complete range is summarized in Table 11 of the
report. As shown on Table II, the predicted worst-case ambient
exposures to PCBs from cement kiln PCB incineration is lower than
background and the air concentrations found in homes or offices.
Similarly, based on available data, dioxin and furan emission
rates and concentrations are also predicted to be so low as to be
without adverse effects to the public health.
An apparent economic incentive exists for cement manufacturers to
burn PCBs. Not only would cement kiln operators be paid for
destroying PCBs, but they would gain a modest fuel savings as
well because the PCBs have heating value.
The staff recognizes that cement kiln operators might have
certain reservations about using kilns for PCB destruction. One
fear is the liability associated with potential personal injury
suits. Another problem may be with public acceptance. Even
though the process would reduce rather than increase the health
risks associated with PCBs, the public may object to PCB
incineration out of a fear of the unknown.
To minimize both the public and the cement kiln owner's concerns
over the risk associated with handling and burning PCBs, it may
be desirable for an independent organization of experts in toxic
waste management to be responsible for all aspects of the PCB
disposal operation. A private firm could literally "rent" the
cement kiln flame from the operator. This firm would be, of
course, heavily insured and would take all responsibility for
every step of the collection, transportation, and destruction
process. The staff is aware of at least one such firm that has
already shown interest in this possibility.
Included in this staff report is a review of alternative methods
for destroying PCBs. Many intriguing possibilities exist,
including other types of incinerators and some chemical methods.
At present, however, none of these methods can match the cement
kiln's advantages, including energy conservation, ability to
accept PCB liquid waste in various strengths, proven destruction
efficiency, and economic incentives.
For the reasons which have been summarized above, the staff
recommends that the Air Resources Board approve the criteria for
cement kiln incineration of PCBs which the staff has proposed and
find that PCB incineration done in compliance with these criteria
is safe from an air pollution perspective. By taking such
action, the Board can facilitate the review and approval of
future proposals for incinerating PCBs in cement kilns thereby
encouraging an environmentally sound approach to one of the
State's most serious hazardous waste disposal problems.
ITEM NO.: 81-4-2
Public meeting to Consider Suggested Control Measure for the
Control of Oxides of Nitrogen Emissions from Electric Utility Gas
Turbines.
SUMMARY AND STATEMENT OF REASONS FOR SUGGESTED CONTROL MEASURE
The staff of the Air Resources Board (ARB) have identified the
need to reduce emissions of oxides of nitrogen (NOx) from
stationary sources in the South Coast Air Basin (SCAB). This
need exists because the state and national ambient air quality
standards for nitrogen dioxide (NO2) are consistently violated in
this air basin. Additionally, emissions of NOx from electric
utility gas turbines contribute to violations of state and/or
national ambient air quality standards for total suspended
particulate, oxidant (ozone) and visibility in the south Coast
Air Basin, the San Diego Air Basin and the San Francisco Bay Area
Air Basin. NOx emissions from electric utility gas turbines,
which have been estimated at 4.6 tons per day in the SCAB during
peak periods of electrical demand, contribute to these
violations. Statewide emissions of NOx from electric utility gas
turbines are estimated by staff to be approximately 3170 tons per
year.
The staff has determined that reducing NOx emissions from
electric utility gas turbines is feasible and cost effective.
Water injection is an abailable emission control technique which
would enable gasturbines to comply with the January 1, 1983
emissions level of the suggested control measure. Water
injection retrofit systems have been developed by most turbine
manufacturers. NOx reductions of about 75 percent of
uncontrolled emissions are achievalble through implementation of
this contro technique. Other control techniques such as
catalytic combustion and selective catalytic reduction are
anticipated to be commercially available to enable gas turbines
to meet the January 1, 1987-1988 rates. Emission reductions from
these control techniques are estimated at 90 percent.
The emission limits contained in the proposed suggested control
measure require an emission reduction of approximately 75 percent
of uncontrolled wxisting gas turbine NOx emissions by January 1,
1983. By January 1, 1988, the emission limits in the proposed
measure will require further reductions so that total emissions
reductions will approach 90 percent of uncontrolled existing gas
turbine emissions. It should be noted that approximately 87
percent of the existing electric utility gas turbines in the SCAB
which are affected by the January 1, 1983 compliance date, are
equipped with either water or steam injection and/or designed for
combined cycle. Of these gas turbines, 90 percent are currently
in compliance with the January 1, 1983 emission level.
The proposed suggested control measure provides that on January
1, 1983, NOx emissions from existing electric utility gas
turbines (those installed before January 1, 1987) shall not
exceed 0.18 microgram per joule output (ug/J) when fired on
methanol or natural gas and 0.28 ug/J for distillate or other
fuels. The measure also provides that on January 1, 1988, NOx
emissions from existing electric utility gas turbines will be
further limited to not more than 0.10 ug/J for methanol or
natural gas and 0.16 ug/J for distillate or other fuels. An
exemption from the January 1, 1983 compliance date only is
provided for existing electric utility gas turbines operated less
than 200 hours per year. For new electric utility gas turbines
(those installed on or after 1987) NOx emissions will be limited
to 0.10 ug/J for methanol or natural gas and 0.16 ug/J for
distillate or other fuels.
The staff estimates the cost-effectiveness of this suggested
control measure to range from $0.23 to $3.80 per pound of NOx
removed. Also, the staff has not identified any potentially
significant adverse environmental impacts associated with the
implementation of this suggested control measure.
The staff report contains detailed discussions of the need for
control of this source, the control technology, and the economic
and environmental impacts of the proposed measure. Also,
included is a copy of the suggested control measure, appendices
regarding testing procedures and a proposed equivalent emission
standards and a list of references to studies reviewed for the
preparation of the staff report.