November 17, 1995

South Coast Air Quality

Management District Board

Introduction

The purpose of Rule 1134 - Emissions of Oxides of Nitrogen from Stationary Gas Turbines, is to provide emission reductions of nitrogen oxides (NOX), which are necessary to attain and/or maintain state and federal ambient air quality standards for nitrogen dioxide (NO2), particulate matter (PM10) and visibility. In order to achieve this, Rule 1134 requires various categories of stationary gas turbines operating in the South Coast Air Quality Management District (AQMD) to meet specific NOX concentration limits. The rule has a final compliance date of December 31, 1995, and applies to all existing stationary gas turbines rated at 0.3 megawatts (MW) or greater which are located within the AQMD jurisdiction.

The origin of the rule can be traced to a 1979 United States Environmental Protection Agency (EPA) New Source Performance Standard for Stationary Gas Turbines. In 1981, the California Air Resources Board (CARB) adopted a Suggested Control Measure for this same equipment. Following this, the AQMD incorporated into the 1982 revision of the Air Quality Management Plan (AQMP), Measure E-1, titled Electric Utility Gas Turbines NOX Control. This led to the adoption of Rule 1134 in 1989 which encompasses various NOX emission limits for a wide range of gas turbine applications.

Facilities subject to Rule 1134 generally include those which utilize gas turbine units to generate electricity. These units add power to the regional electrical power grid directly or displace utility-supplied power by on-site power generation with the surplus power, if any, going to the grid. The electrical energy supply market can be categorized into three segments: utilities, on-site generators and third-party-owned cogenerators. Exclusive on-site power units are typically less than 10 MW in size. The third-party-owned cogenerator units generally range in size from 20 to 40 MW, though some are less than 10 MW or greater than 40 MW. Utility units, both simple and combined cycle, range in size from about 20 to greater than 130 MW. At the time of the rule's adoption in 1989, it was estimated that the gas turbine capacity in the AQMD was 2,473 MW, with 1,985 MW in operation and 488 MW of new units to be completed. The AQMD-wide NOX emissions as a result of the rule were expected to be reduced from 18.9 tons per day to 8.9 tons per day for a net reduction of 10 tons per day.

Proposed Amendments

Rule 1134 presently requires all stationary gas turbines in the AQMD to meet specified NOX concentration limits by December 31, 1995. The limits are dependent upon the size (MW rating) of the unit and type of control technology utilized. Exemptions apply to certain types of turbines such as emergency standby and peaking units which operate less than 200 hours per year; laboratory units used in research and testing; units used exclusively for firefighting and/or flood control; or existing chemical processing units.

Beginning in 1994, a large number of utilities and third-party-owned cogenerators were included in the Regional Clean Air Incentives Market (RECLAIM) program and as such are not required to meet the NOX concentration limits imposed by Rule 1134. However, gas turbines used at publicly-owned treatment works (POTWs), landfills, hospitals and other public facilities, and smaller sources which were not covered under RECLAIM, are still required to meet the concentration limits in Rule 1134 through application of various control technologies.

Of those non-RECLAIM sources required to meet the NOX concentration limits, some have raised concerns indicating that the application of available technology is not suitable for a number of reasons. Some of these units are operated so infrequently and in such remote areas of the AQMD that add-on controls, or combustion modifications, if available, are not cost-effective. The gas turbines located in the Southeast Desert Air Basin (SEDAB) are in a geographical area where NOX, ozone and some of the PM10 concerns are transient and as a direct result of emissions generated within the South Coast Air Basin (SCAB). The SEDAB includes specific desert portions of Los Angeles, Riverside and San Bernardino Counties within the jurisdiction of the AQMD. Also, the gas turbines located on San Clemente Island (SCI) are in such location that any NOX emissions generated from the island do not impact the air quality in SCAB. The only facility on SCI was recently removed from the RECLAIM program for the same reason.

This proposed rule amendment will provide an exemption to specified existing gas turbines located in SEDAB, and all existing gas turbines on SCI. The main factors which provided the basis for this proposed amendment are listed below:

• The number of gas turbine sources located in SEDAB are few; a total of 23 units have been identified in SEDAB, 17 of which have an equivalent rating below 2.0 MW.

• The number of gas turbine sources located on SCI are few; a total of 4 units have been identified, all of which have an equivalent rating below 1.0 MW.

• The contribution to AQMD-wide emissions from all SEDAB and SCI gas turbines combined is minimal in comparison to other SCAB sources.

• NOX Control Measures for both the Antelope Valley and Riverside County SEDAB are not compromised by exempting all sources from the rule requirements. The 1994 AQMP does not emphasize any further NOX control measures to be implemented in SEDAB.

• The total amount of reductions possible as a result of successfully applying controls to both SEDAB and SCI sources is not expected to create a significant cumulative impact to the overall air quality in the AQMD. Control of these sources combined would yield only one percent of the total NOX emission reductions which were expected when the rule was adopted in August, 1989.

• The sources identified in SEDAB and SCI either cannot physically retrofit or apply add-on controls, or cannot implement cost effective controls to meet rule requirements.

• The sources in SEDAB and SCI which are proposed to be exempted historically have low annual usage rates in comparison to their maximum possible operations. Specifically, Gas Company units (SEDAB) have operated an average of less than 20 percent of the time over the last four years. The Rockwell (SEDAB) and SCI units have operated less than one percent of the year on average for the last three years.

A Public Workshop was held for this rule on August 18, 1995. The Public Hearing is scheduled for December 8, 1995. As per the Notice of Public Hearing, written comments will be accepted through November 28, 1995.

Pursuant to the AQMD's Certified Regulatory Program (Rule 110) the AQMD has prepared appropriate California Environmental Quality Act (CEQA) documentation consisting of a Draft Supplemental Envirommental Assessment (SEA). The Draft SEA has been circulated for a 45-day public review and comment period and is included as part of this package. A Final SEA will be prepared which will include response to comments received on the Draft SEA.

THEREFORE, IT IS RECOMMENDED THAT YOUR BOARD

--Set a public hearing for the December 8, 1995 Board meeting to amend Rule 1134 - Emissions of Oxides of Nitrogen from Stationary Gas Turbines

Respectfully,

James M. Lents, Ph.D.

Executive Officer

Attachments

PL:CC:MN:CHJ

(1134bl.doc)