August 11, 1995
South Coast Air Quality
Management District Board
Introduction
The purpose of Rule 431.1, Sulfur Content of Gaseous Fuels, is to reduce Sulfur Oxides (SOx) emissions from combustion of gaseous fuels. SOx emissions result in, or contribute to, the formation of air pollutants such as sulfur dioxide (SO2), sulfates (SO4) and particulate matters (PM10), for which ambient air quality standards have been adopted. SOx emission reductions from this rule support the South Coast Air Quality Management District's (AQMD's) efforts in demonstrating progress towards attainment or maintenance of ambient air quality standards for these pollutants.
Facilities subject to Rule 431.1 generally include refineries, utilities, oil and gas production facilities, sewage treatment plants and landfills. Rule 431.1, sets limits for sulfur in gaseous fuels burned in stationary combustion equipment operated at these facilities. Rule 431.1 was originally adopted in November 1977 and has subsequently been amended a number of times to implement additional Air Quality Management Plan (AQMP) control measures reflecting advances in control technology and to extend compliance deadlines, when necessary. Prior to a January 1982 amendment, the rule had limits for total sulfur of 80 parts per million (ppm) for all gaseous fuels to be sold for use in AQMD and 800 ppm for all gaseous fuels to be burned on-site. In January 1982 Rule 431.1 was amended to expand the coverage of the rule to limit total sulfur for resource recovery gases (sewage digester and landfill) to 250 ppm to be sold for use in AQMD and 800 ppm to be burned on-site.
In May 1990, Rule 431.1 was amended to implement additional AQMP control measures by providing a single total sulfur limit of 40 ppm for all gaseous fuels to be burned or to be sold for use in the AQMD, with a final compliance date of May 4, 1992. The amendment also included a requirement to install and properly operate a continuous monitor to measure total sulfur in the fuel or SOx emissions at the stack, by the compliance date. Because of the unavailability of the continuous total sulfur monitors, the rule was once more amended in October 1992, to extend the compliance date until May 4, 1994. Also, because of the economic impact that the 40 ppm limit would impose on small refiners, the amendment included an extension of the final compliance date for small refiners until May 4, 1996.
All of the facilities subject to Rule 431.1 comply with the sulfur limit requirements in effect prior to the final compliance date of May 1994. With the adoption of the Regional Clean Air Incentives Market (RECLAIM) program in October of 1993, facilities subject to RECLAIM did not have to comply with certain command and control regulations, such as Rule 431.1. This mainly included refineries. In general, with the exception of some landfills and POTWs, all other non-RECLAIM sources are presently in compliance with the existing requirements of Rule 431.1.
Proposed Amendments
A number of concerns have arisen in the course of implementing the most recent amendments to Rule 431.1. First, as the May 1994 final compliance date approached, cost-effective control technologies to remove sulfur compounds from landfill gas were not available. Thus, landfills could not comply with the 40 ppm total sulfur limit. Landfill facilities requested additional time to investigate the feasibility and cost effectiveness of various control technologies to remove or to control sulfur compounds present in landfill gas. This resulted in variance proceedings for several of the landfill facilities. These variances were granted and are due to expire at the end of this year.
Second, with refineries now under RECLAIM, they are no longer subject to certain command-and-control rules, such as Rule 431.1. However, some refineries sell gaseous fuels to non-RECLAIM SOx facilities. Although the seller is not prohibited from selling its fuel gas, Rule 431.1 does not allow the non-RECLAIM facility to buy and/or to burn this non-compliant gas in its equipment. Both the RECLAIM and non-RECLAIM sources have requested an exemption to allow the non-RECLAIM source to continue to purchase and burn such non-compliant gas.
Third, the POTWs and landfills requested additional flexibility to comply with the rule by increasing the averaging period for total sulfur limit. This allows these facilities to better handle process upsets and could result in additional cost savings.
Finally, the October 1992 amendment included an extension of the compliance date for small refiners from May 1994 to May 1996. During this amendment, however, an interim limit was inadvertently omitted, which is now addressed in this proposal.
These issues prompted staff to revisit the rule once more. From the comments received during or after the public workshops, staff has addressed a number of issues and incorporated specific changes in this proposal. The main changes include:
_ extension of final compliance date for landfill facilities until July 1997 and incorporation of an interim daily limit of 150 ppm sulfur in landfill gas,
_ increased averaging period for resource recovery gases from 4 hours to daily,
_ option to comply with a monthly averaging period for resource recovery gases with a total sulfur cap of 200 ppm for landfill gas and 500 ppm for sewage digester along with continuous monitoring to determine the total sulfur in the fuel gas, or SOx from the stack,
_ option to allow facilities which burn gaseous fuels in two or more different pieces of equipment, to comply with the sulfur limit on the aggregate within the facility, rather than for individual equipment in which the fuel is burned,
_ an extended compliance schedule for facilities that were previously exempt or were previously in compliance, but because of the change in gas production rate or gas quality, would have to control sulfur compounds in the gaseous fuel in order to comply with the rule requirements. To avoid immediate violation, these facilities are given 18 months from the date of non-compliance, or July 1997, whichever is later, to comply with the total sulfur limit,
_ quality assurance/quality control requirements for continuous monitors in order for these monitors to be used to implement and enforce the rule,
_ an exemption for facilities subject to the requirements of this rule to allow them to buy and burn such non-compliant fuel gas from a SOx RECLAIM facility. This is provided that all of the SOx emissions generated from the burning of the subject fuel shall be reported as SOx emissions from the SOx RECLAIM facility, and
_ a guideline for approval of an alternative monitoring plan by the Executive Officer.
Other proposed changes are mainly for the purposes of clarification and improved enforceability.
Conclusions
Pursuant to the California Environmental Quality Act (CEQA), the AQMD has prepared a Draft Supplemental Enviromental Assessment (EA) for the proposed amendments to Rule 431.1. The Draft Supplemental EA is currently circulated for a 45-day public review and comment period, which ends September 1, 1995. All written comments received will be included in the Final Supplemental EA.
In addition, the AQMD has prepared a draft Socioeconomic Assessment, which addresses the socioeconomic impacts of the proposed amendments to Rule 431.1. The draft Socioeconomic Assessment is included as part of the draft staff report.
Two public workshops were held for the proposed amendments to Rule 431.1 on April 28, 1995 and July 5, 1995. The Public Hearing is scheduled for October 13, 1995. As per the Notice of Public Hearing, written comments will be accepted through August 29, 1995. All written comments received by this date will be reviewed and responded to by staff in the final Public Hearing Staff Report for the rule.
As a result of either the CEQA or rule comments, staff may propose additional changes to Proposed Amended Rule 431.1.
THEREFORE, IT IS RECOMMENDED THAT YOUR BOARD
Set a Public Hearing for October 13, 1995 to certify the Environmental Assessment and adopt Proposed Amended Rule 431.1 - Sulfur Content of Gaseous Fuels.
Respectfully,
James M. Lents, Ph.D.
Executive Officer
PL:LL:MN:LB
Attachments
(blt4311)
ATTACHMENT A
Summary of Proposed Amendments to Rule 431.1 - Sulfur Content of Gaseous Fuels Provide a three (3) year extension of the final compliance date for landfill gas until July 1997. Provide an interim daily limit of 150 ppm for total sulfur in landfill gas until the final compliance date. Change the sulfur limit averaging period for resource recovery gases from four hours to: daily with daily, or continuous monitoring, or monthly with continuous monitoring and peak total sulfur limits of 200 and 500 ppm (at 15 minute average) for landfill gas and digester gas, respectively. Allow additional flexibility for resource recovery gases to comply with the final total sulfur limit on the aggregate within a facility rather than for individual equipment. Provide compliance schedule and additional time to comply for facilities that were previously exempted from the rule or previously in compliance without added control. Provide an interim limit for small refiners (which was inadvertently omitted during the last amendment) until the final compliance of May 1996. Add an exemption for non-RECLAIM SOx facilities to be able to sell or to buy from RECLAIM facilities a non-compliant gaseous fuel (and burn) provided that the resulting SOx emissions are included in the SOx RECLAIM facility's emissions allocations. Clarify some provisions and add definitions of terms for improved compliance and enforceability.
attacha.doc
ATTACHMENT B
RULE DEVELOPMENT PROCESS
ATTACHMENT C
KEY CONTACTS LIST
_ Environmental Agencies
Environmental Protection Agency, Region IX
California Air Resources Board
_ Public Agencies
City of Los Angeles, Bureau of Sanitation
City of Palm Springs, Wastewater Treatment Plant
County of Orange Integrated Waste Management Department
Eastern Municipal Water District
Sanitation Districts of Los Angeles County
Sanitation Districts of Orange County
_ Organization
Western States Petroleum Association
_ Companies
Bradley Landfill & Recycling Center
Carnot
Chevron U.S.A.
Mobil Oil Corporation
Laidlaw Environmental Services
Pacific Energy
Southern California Edison
Waste Mangaement Recycling and Disposal Services of Southern California
(ATTACH.DOC)
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
Draft Staff Report for
Proposed Amended Rule 431.1 - Sulfur Content of Gaseous Fuels
Dated: July 1995
Office of Stationary Source Compliance
Deputy Executive Officer
Pat Leyden, A.I.C.P.
Assistant Deputy Executive Officer
Lee Lockie
Senior Manager
Mohsen Nazemi, P.E.
Authors: Linda Basilio - Air Quality Engineer
Robert Kneisel - Staff Specialist
Reviewed by: Mohsen Nazemi, P.E. - Senior Manager
William Wong - Senior Deputy District Counsel
Cindy Greenwald - Planning and Rules Manager
Technical Assistance: George Ames John Higuchi
Robert N. Kwong Sue Lieu
Rod Millican Tara Sheehy
Steve Smith William Thompson
Gary Turner Hubert Wilson
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
GOVERNING BOARD
Chairman: JON D. MIKELS
San Bernardino County Representative
Vice Chairman: WILLIAM A. BURKE, Ed.D.
Speaker of the Assembly Appointee
MEMBERS:
MICHAEL D. ANTONOVICH
Los Angeles County Representative
MARVIN BRAUDE
Cities Representative, Los Angeles County, Western Region
CANDACE HAGGARD
Cities Representative, Orange County
HUGH HEWITT, Esq.
Governor's Appointee
MEE HAE LEE
Senate Rules Committee Appointee
RONALD O. LOVERIDGE
Cities Representative, Riverside County
LEONARD PAULITZ
Cities Representative, San Bernardino County
JAMES SILVA
Orange County Representative
NELL SOTO
Cities Representative, Los Angeles County, Eastern Region
S. ROY WILSON, Ed.D.
Riverside County Representative
EXECUTIVE OFFICER
JAMES M. LENTS, Ph.D.
T A B L E O F C O N T E N T S
CHAPTER I - SUMMARY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I-1
A. Executive Summary
B. Draft Findings
C. Background
CHAPTER II - PROPOSED AMENDMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . II-1
A. Definitions
B. Rule Requirements
C. Exemptions
D. Monitoring Criteria
CHAPTER III - CONTROL TECHNOLOGY ASSESSMENT. . . . . . . . . . . . . III-1
CHAPTER IV - EMISSION IMPACTS. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . IV-1
CHAPTER V - COMMENTS AND RESPONSES. . . . . . . . . . . . . . .. .. . . . . . . V-1
A. EPA Comments
B. Public Comments
CHAPTER VI - DRAFT SOCIOECONOMIC ASSESSMENT. . . . . . . . . . . . . .VI-1
APPENDIX I - Time Schedule for Gas Desulfurization
Technology Review . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . .AI-1
APPENDIX II - List of Gas Desulfurization Technologies
Considered . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . AII-1
APPENDIX III - Survey of SCAQMD Landfills List. . . . . . . . . . . . . . . . . . . . . AIII-1
APPENDIX IV - Survey of SCAQMD POTWs List. . . . . . . . . . . . . . . . . . .. . .AIV-1
APPENDIX V - Proposed Language for Amended Rule 431.1 . . . . . . . . . . . . . . AV-1
CHAPTER I
S U M M A R Y
A. EXECUTIVE SUMMARY
The purpose of Rule 431.1, Sulfur Content of Gaseous Fuels, is to reduce sulfur oxides (SOx) emissions from burning of gaseous fuels in stationary combustion equipment. Rule 431.1 sets a limit for total sulfur compounds in gaseous fuels at 40 parts per million (ppm), calculated as hydrogen sulfide. The existing rule has a final compliance date of May 4, 1994. In order to monitor the concentration of sulfur in the fuel, the rule also requires installation and proper operation of a continuous monitor to determine the sulfur content in the fuel gas or to determine the SOx emissions in the stack after combustion of the fuel. The proposed amendments are intended to provide a three year extension of time for landfills and additional flexibility for other affected facilities to comply with the rule requirements. No new Air Quality Management Plan (AQMP) control measures are being implemented through the proposed amendments
Facilities subject to Rule 431.1 generally include refineries, utilities, oil and gas production facilities, and Publicly Owned Treatment Works (POTWs) and landfill facilities which produce sewage digester and landfill gases, respectively. The refineries are subject to Regional Clean Air Incentives Market (RECLAIM), and thus are not now required to comply with the existing 40 ppm total sulfur limit. The refineries are also in the process of having their respective monitoring systems certified by the South Coast Air Quality Management District (AQMD) in compliance with Rule 431.1 and/ or RECLAIM requirements.
POTWs and landfill facilities are still subject to Rule 431.1 since they are not included in the RECLAIM program. Sewage digester and landfill gases, or biogases, also differ from refinery and produced gases in terms of chemical composition. While refinery gas is virtually dry and consists of heavier hydrocarbons, such as ethane, propane, etc, with heat content usually more than 1100 Btu per cubic foot, biogases consist of moisture, carbon dioxide and light hydrocarbon, mainly methane, with heat content about half as high as that of the refinery gas. Because of the intervening reaction of carbon dioxide with the reagents for removal of sulfur compound from the fuel gas, the sulfur removal technologies that are now available in refineries cannot be directly transferred to biogases. Also, because of the presence of moisture in the biogases, any continuous monitor applicable to refinery gas cannot be directly applicable to biogases. Several of these landfills and sewage digesters have obtained regular variances from the AQMD Hearing Board. Landfill operators requested, and this proposed rule amendment contains, an extension of the 40-ppm final compliance date until 1997, to allow completion of a comprehensive study on the feasibility and cost of sulfur removal technology.
Incidentally, facilities which are subject to RECLAIM, such as the refineries, will no longer be subject to Rule 431.1, once their monitoring systems are certified by the AQMD. While under RECLAIM, these refineries may burn on-site or sell to another facility gaseous fuels which exceed Rule 431.1 sulfur limit. Although the RECLAIM facilities can sell their non-compliant fuel gas, a buyer has to be subject to RECLAIM or in compliance with Rule 431.1 requirement. One refinery is presently selling non-compliant gaseous fuel to a non-RECLAIM utility company. As claimed by the seller, this fuel gas is in excess of the refinery's demand, and if the sale is not allowed, the gas would be flared without energy recovery. While the refinery is flaring its excess gas, the prospective buyer will be purchasing and burning natural gas equivalent to the amount not received from the refinery. An exemption has been requested in Rule 431.1 to allow for such a sale to take place. Also a variance has been petitioned by both the seller and the buyer and granted by the AQMD Hearing Board to allow such a sale.
During the October 1992 amendment of the rule, the final compliance date for small refiners was extended from May 1994 to May 1996. With the extension, however, the interim limit was inadvertently omitted.
During the present rulemaking process, POTWs and landfill operators have requested to increase the averaging period from 4 hours to a longer period to accommodate for any uncontrolled upsets in the system. Also, one POTW has requested an optional compliance plan which will allow them to achieve the same SOx emission reduction within the facility using a different scenario with greater operational flexibility and cost savings.
A concern has also been expressed regarding facilities that have previously been exempted due to having low emissions (5 lbs per day sulfur as hydrogen sulfide) or that have previously been in compliance without any control technology applied. However, due to changes in gas quality, such facilities may become subject to the rule and will be obligated to install control systems. The POTWs and landfill operators requested a compliance schedule be incorporated in the rule to avoid immediate violation.
The issues with biogases and the non-RECLAIM facilities gas purchase from the RECLAIM facilities prompted staff to revisit the rule once more. All of the above changes have been incorporated in the proposed amendments to Rule 431.1.
The proposed amendments will result in a delay of SOx emission reductions, as well as potential SOx emission increases. There have already been emission reductions foregone between May 4, 1994 and the present, as a result of certain landfill facilities currently not complying with the 40 ppm total sulfur limit while operating under Hearing Board variances. The expected foregone SOx emission reductions are estimated to be an average of 0.25 ton per day, and under hypothetical worst case could be as high as 1.39 tons per day.
Additional emission increases may be expected as a result of the new monthly averaging period proposed in these amendments. The worst case SOx emission increases from the sewage treatment facilities due to the monthly averaging provision is estimated to be about 0.8 ton on a single day in any month.
Therefore, the combined worst case emission impacts as a result of the proposed amendments could be as high as 2.19 tons per day of SOx. However, a more likely scenario would result in much lower excess SOx emissions in any one day. The air quality impacts associated with the proposed amendments are above the AQMD SOx significance threshold, and thus they are considered to be significant. However, the proposed amendments facilitate development of feasible and cost-effective gas desulfurization technologies, while providing increased flexibility and possible cost savings to the affected sources. No new AQMP control measure is being implemented through these amendments.
B. DRAFT FINDINGS
Health and Safety Code Section 40727 requires that prior to adopting, amending or repealing a rule or regulation, the District Board shall make findings of necessity, authority, clarity, consistency, nonduplication, and reference based on relevant information presented at the hearing.
Necessity - The AQMD Governing Board finds and determines that the proposed amendments to Rule 431.1 - Sulfur Content of Gaseous Fuels, is necessary for the following reasons:
a. To provide a 3 year extension to the final compliance date for landfill gas in order to allow for investigation of feasibile and cost-effective control technologies and to provide an interim total sulfur limit until final compliance date.
b. To increase the sulfur limit averaging period for resource recovery gases to facilitate compliance during upset connditions.
c. To allow additional flexibility for the exchange of gaseous fuels between gas producers and gas users.
d. To provide a compliance schedule for subject facilities that are previously exempted or previously in compliance without added controls to facilitate compliance due to changes in the quality or quantity of gases produced.
Authority - The AQMD Governing Board obtains its authority to adopt, amend or repeal rules and regulations from California Health and Safety Code Sections 39002, 39650 et seq., 40000, 40001, 40440, 41508, 41700, 40702, and 42300.
Clarity - The AQMD Governing determines that Rule 431.1 has been amended in response to public comments from persons affected by the rule, and as a result, its meaning can be easily understood by the persons directly affected by it.
Consistency - The AQMD Governing Board determines that Proposed Amended Rule 431.1 is in harmony, and not in confllict with or contradictory to, existing federal or state statutes, court decisions or regulations.
Non Duplication - Proposed Amended Rule 431.1 does not impose the same requirements as any existing state or federal regulations, and is necessary and proper to execute the powers and duties granted to, and imposed upon the District.
Reference - In adopting the Proposed Amended Rule 431.1, the AQMD Governing Board references the following statutes which the AQMD hereby implements, interprets or makes specific: Health and Safety Code Sections 40001 (rules to achieve ambient air quality standards), 40440(a) (rules to carry out the Air Quality Management Plan), and 40910 et.seq. (California Clean Air Act).
The proposed amendments to Rule 431.1 are a "project" as defined by the California Environmental Quallity Act (CEQA) (California Public Resources Code Section 21000 et seq.). The AQMD is the lead agency for the project and has prepared a Draft Supplemental Environmental Assessment (EA) pursuant to its certified regulatory program (California Public Resources Code Section 21080.5). AQMD's regulatory program, Rule 110, was certified by the Secretary of the Resources Agency on March 1, 1989. The Draft Supplemental EA analyzes the potential environmental impacts of the proposed amendments to Rule 431.1, and is currently being circulated for a 45-day public comment period. All written comments received on the Draft Supplemental EA will be included in the Final Supplemental EA.
C. BACKGROUND
Rule 431.1 - Sulfur Content of Gaseous Fuels, was first adopted in November 1977 and was subsequently amended eight different times, with the most recent amendment in October 1992. The purpose of the rule is to reduce SOx emissions from burning of gaseous fuels in stationary combustion equipment. In order to achieve that, Rule 431.1 imposes limits on total sulfur content of gaseous fuels.
Until January 1982, Rule 431.1 had limits for sulfur compounds in gaseous fuels, except sewage digester gas (landfill gas was not subject to the rule at that time), sold at 80 parts per million by volume (ppmv) and burned on-site at 800 ppmv. The 1982 amendment set limit for sulfur in sewage digester and landfill gas at 250 ppmv to sell and 800 ppmv to burn on site.
At the January 1982 public hearing, the Board instructed staff to investigate whether or not a single limit would be possible for all fuel gases either sold or burned on-site. Staff's investigation indicated that, at the time, refineries experienced excursions in their make-gas sulfur content, which approached the 800 ppm level. The May 1983 amendment, therefore, maintained the three different limits: 250 ppmv for landfill and sewage digester gases for sale; 80 ppmv for other gaseous fuels for sale; and 800 ppmv for all gaseous fuels for on-site burning.
The rule was revisited in 1990 to review the sulfur removal technology and associated costs to implement Control Measure 88-F-2 of the 1989 Air Quality Management Plan. The measure recommended a uniform sulfur limit for both off-site sales and on-site burning. As a result of the investigation, the 1990 amendment was adopted with a uniform sulfur limit of 40 ppm by volume for off-site sales or on-site burning, with a final compliance date of May 4, 1992. The amendment also required a continuous sulfur fuel monitor to be installed by May 4, 1992. Because a continuous total sulfur monitor was not available in the market and staff investigation showed that appropriate continuous total sulfur monitor could not be developed in time for the 1992 compliance date, the rule was amended in April 1992 to extend the continuous sulfur monitor requirement for another year. Subsequent amendments were adopted to provide additional time extensions to develop sulfur removal technology and a continuous total sulfur monitoring system, with a final compliance date of May 4, 1994.
The October 1992 amendment also included an extension of the 40-ppm final compliance for small refiners from May 1994 to May 1996. This extension was consistent with California Air Resources Board's (CARB's) two-year extension for small refiners to comply with the Phase II Reformulated Gasoline requirements.
PROPOSED AMENDMENTS
Rule 431.1 presently sets the total sulfur limit at 40 ppmv averaged over a consecutive 4-hour period effective May 4, 1994. With the rule now in effect, several compliance issues are of concern, especially for landfill and POTWs facilities that have triggered this rule amendment. Another issue addressed in this amendment is the consideration of an exemption for certain facilities that are not subject to RECLAIM, and as such, are subject to the command-and-control limits of Rule 431.1, but which purchase and burn gaseous fuels from a RECLAIM facility.
A. DEFINITION
As a result of the proposed amendments a few new definitions have been added to the rule. Below is a brief discussion of some of the new definitions.
1. Daily average
The term is defined for landfills and sewage digester facilities who seek alternative fuel gas monitoring system (AFGMS) for sulfur instead of continuous fuel gas monitoring system (CFGMS) or continuous emission monitoring system (CEMS). Some refineries have already installed CFGMS for their refinery gas. Landfill gas and sewage digester gas differ from refinery gas in terms of constituents. Both biogases contain significant amount of moisture and carbon dioxide which could interfere with the sulfur monitoring process. Staff allowed an alternative system of monitoring sulfur compounds in the fuel gas by obtaining multiple samples within the averaging period. As approved by the AQMD, these samples have to be taken at certain time intervals to obtain a representative reading for the given period. Also, a test for total sulfur according to AQMD Test Method 307-91 requires a detailed analytical testing of samples in the laboratory by gas chromatography. Staff may allow operators to establish a correlation between hydrogen sulfide and total sulfur compounds. Once a correlation is established, colorimetric testing can be conducted to determine the total sulfur compounds in the fuel gas using hydrogen sulfide as a surrogate . In order to have a consistent methodology of approving these alternative monitoring plans, a guideline is prepared as an addendum to this proposed amendment. These alternative monitoring plans require daily averaging of test data. A definition of "daily average" is then incorporated in this proposal as referenced in the guideline for AFGMS approval.
2. Monthly Weighted Average Sulfur Content
Rule 431.1 requires electric power plants and refineries to submit monthly report to the AQMD on the daily fuel consumption and the average sulfur content of the fuel burned for the month. In order to obtain a more accurate accounting of SOx emitted from the burning of such fuel, a weighted average sulfur value would be appropriate. Fuel gas production rates or gas consumption at each of the Rule 431.1-affected facilities vary from day to day. Also, the sulfur loading in the gas fluctuates with the operating parameters, or with the ambient conditions. An arithmetic mean of the sulfur values would not yield a representative quantification of SOx emissions. Staff is proposing the use of weighted average in calculating SOx emissions for refineries and utility generating plants. A definition of "weighted average" is added for reference.
Landfill and POTWs facilities have relatively constant fuel gas production rates from one day to another. Although the gas production rates may change monthly or yearly, using the weighted average sulfur content in the fuel gas will not make a significant difference in calculating the actual SOx emissions, compared to using an arithmetic mean. The weighted average requirement, therefore, does not apply to landfills and POTWs.
3. RECLAIM SOx Facility
Certain facilities are now subject to RECLAIM SOx Regulations. These facilities are no longer subject to Rule 431.1, once they comply with RECLAIM's monitoring and reporting requirements as specified in Rule 2001 - "Existing Rule Provisions Not Applicable to RECLAIM Facilities for SOx". An exemption is now proposed to allow non-RECLAIM facilities to purchase and burn gaseous fuels from these RECLAIM facilities. For reference, a definition of "RECLAIM SOx Facility" is then added in the proposed amendment.
4. Others
The terms "CEMS", "emergency vent gas", "refinery gas", "standard conditions", and "stream day" are already in the existing rule. Definitions of these terms are also proposed along with other terms, such as, "CFGMS", and are incorporated in this proposed amendment for reference and clarification purposes only.
B. RULE REQUIREMENTS
In an effort to simplify the rule requirements and for easy reference of the different sulfur limits and corresponding compliance dates, the sulfur limits and corresponding compliance dates are tabulated in the proposed version of the rule. Table 1 below shows specific sulfur limits, along with the averaging periods and final compliance dates for various types of gaseous fuels.
TABLE 1
Fuel Type Sulfur Limits Averaging Compliance Date
ppmv Period On or After
Refinery Gas
Small Refiners 40 4 hrs May 4, 1996
Other Refiners 40 4 hrs May 4, 1994
Landfill Gas 150 Daily Adoption Date
40 or Daily or July 1, 1997
40/200 Monthly/
15-minutes July 1, 1997
Sewage Digester Gas 40 or Daily or May 4, 1994
40/500 Monthly/- Adoption
15 minutes date
Other Gases 40 4 hrs May 4, 1994
The following is a discussion of the sulfur limits and other compliance requirements described in the proposed amendments.
1. Small Refiners
The October 1992 amendment of the rule included an extension for small refiners to comply with the final sulfur limitation starting May 1996, that is, a two-year delay from large refiners' compliance date. During that amendment, however, an interim limit from May 1994 to May 1996 was inadvertently omitted. Prior to the last amendment, small refiners were subject to the 80 ppm limit to sell and 800 ppm limit to burn on-site. Staff now proposes to re-instate for small refiners the 80 ppmv and 800 ppmv limits for "sales" and for "own-use" gases, respectively, until final compliance on May 4, 1996. Likewise, the continuous emissions monitoring system requirement is extended until the new final compliance date of May 4, 1996.
2. Sewage Digester Gas
The City of Los Angeles's Hyperion Treatment Plant is presently using a chemical, ferrous chloride (as do other sewage treatment facilities), to keep the sulfur compounds soluble in the liquid, thus minimizing the sulfur compounds in the produced gas. The addition of chemical upstream of the digester reduces the sulfur compounds in the digester gas from as high as 2500 ppm to about 500 ppm. This gas is charged into the Lo-cat unit. The City initially constructed a Stretford unit about 10 years ago to reduce sulfur. The Stretford unit, however, did not operate as expected, which caused the unit to be shut down. This unit was modified to a Lo-Cat unit, which has been in operation for the past couple of years, to remove the sulfur compounds from the fuel gas by 96 percent, or to a concentration of 20 ppm. The Lo-Cat unit operates smoothly with the desired results, but occasionally experiences mechanical breakdowns or chemical imbalances. The City obtained a variance from the AQMD Hearing Board from the requirements of Rule 431.1 for these upset conditions, which expired in February 1995.
To comply with the variance conditions, the City submits a monthly report of the daily hydrogen sulfide content of sewage digester gas produced from the Hyperion facility. The report shows that as long as the control unit - the Lo-Cat unit, is operating smoothly the sulfur content of the gas is well below the 40 ppm limit (10 to 30 ppm). The Lo-Cat unit is expected to reduce sulfur in the gas stream by 96 percent, except during breakdowns or chemical imbalances. Since presently the inlet sulfur concentration to the unit is at 500 ppm, during upset conditions the outlet sulfur concentration could also reach levels up to 500 ppm. The City, in the past, has doubled the chemical injection, with an additional cost of $250,000/yr for chemicals, to reduce the sulfur concentration at the inlet of the Lo-Cat unit to about 200 ppm and to increase the reliability of the unit's performance. The additional cost, however, still does not comply with the sulfur limit of 40 ppm during upsets, but would only reduce the peak concentrations from 500 to 200 ppm . Staff, therefore, proposes to change the averaging time from 4 hours to daily with an option to have a monthly averaging and a maximum peak of 500 ppm provided that a continuous monitor is installed in the system and properly operated. In order to comply with the 40 ppm monthly average limit, however, the City cannot operate at 500 ppm levels for extended periods of time (less than two days).
As indicated above, POTWs and landfill facilities have difficulty applying the CFGMS that are now used in refineries due to having different gas compositions. Refinery gases are typically dry and have higher hydrocarbon content. Landfill and sewage digester gases have relatively higher moisture, nitrogen and carbon dioxide contents, and lower hydrocarbon content. In most cases, carbon dioxide present in the fuel gas competes with hydrogen sulfide in its reaction with reagents. This competing reaction results in a higher operating cost and increased waste disposal problem. The interference of carbon dioxide in the reaction is one of the major factors to be considered in selecting a control technology for sulfur removal. The chemical characteristics of these biogases are a major reason any CFGMS used in refineries cannot be directly transferred to biogases.
Where a CFGMS is not available, periodic testing within a specified averaging period can be allowed as an alternative to continuous monitoring. This could mean multiple testing spread over the specified averaging period. Where a CFGMS is not available, the guideline provided in the proposed amendment will be used to review and approve the alternative monitoring plan.
3. Landfill Gas
Presently, landfill facilities are conducting studies to remove sulfur compounds from landfill gases in an efficient and cost effective manner. To allow landfill facilities to continue with the study and run a pilot plant for sulfur removal technologies, staff is proposing an extension of final compliance date for landfills to July 1, 1997. An interim daily limit of 150 ppmv is proposed, which will be effective upon adoption of the proposed amendments and until final compliance date of July 1997. Because landfill operating parameters are solely dependent on ambient conditions, the sulfur content of landfill gas is generally beyond the operator's control. Due to the wide fluctuations of the sulfur content in landfill gases, especially during rainfalls, staff proposed to change the averaging period from 4 hours to daily. For enforcement purposes, a daily averaging is proposed, which could be complied with via daily sampling. Consistent with sewage digester gas limitation, a monthly averaging is also proposed with a maximum peak of 200 ppm, provided that a continuous monitor is installed and properly operated.
Although most landfills have average sulfur concentrations lower than the 40-ppmv limit, some landfills have average sulfur content well above the limit. Several landfill facilities, such as the County Sanitation Districts of Los Angeles, Laidlaw, BKK Landfill, and BFI Waste Systems, are now under regular variance from Rule 431.1, most of which expire at the end of this year.
The Sanitation Districts of Los Angeles County is acting as the lead agency which, in cooperation with other landfill operators, is conducting an investigation of the cost-effective technologies to control or remove sulfur compounds from landfill gas. The Sanitation Districts of Los Angeles County prepared a time table, shown in Appendix I, indicating an anticipated completion of the study (with recommendations) sometime in November, 1995. Based on the recommendations, a pilot project can be run before a full-size unit can be constructed and operated, and be in compliance by July 1997. The Sanitation Districts of Los Angeles County requested to delay final compliance until July 1997 to allow research and application of control technology. Staff, therefore, recommends a July 1997 final compliance with interim limit of 150 ppmv until such final compliance date.
4. Other Gases
This requirement applies to other gaseous fuels, such as gases produced in oil and gas production facilities. The requirements for these gases are the same and have not changed in the proposed amendments.
5. Optional Facility Compliance Plan (OFCP)
The Sanitation District of Los Angeles County operates forty-one digesters at the Joint Water Pollution Control Plant (JWPCP) in Carson, with a total gas production of about 9 million cubic feet per day (MMCFD). About 80% of the gas produced is burned at its combined cycle power plant. The other 20% is burned in its utility equipment, such as, standby power generator, boiler, pump-drive engines, etc., and any excess gas is flared. The Sanitation District of Los Angeles County requested to allow a facility-wide averaging as an option to comply with the rule limit. Under this proposal, some of the sulfur in the gas is controlled by cheaper technologies, such as chemical addition upstream of the digesters to levels greater than 40 ppm. Then the remainder of the gas is over-controlled by "post-control" systems to levels below the 40 ppm. The resulting facility-wide SOx emissions would be the same as if all the gas produced were at 40 ppm.
The goal of Rule 431.1 is to reduce SOx emissions from the burning of gaseous fuels. The proposed alternative compliance plan will provide flexibility for facilities, such as POTWs, to comply with the requirements with less financial burdens. This flexibility is proposed primarily for rule compliance and not for new source review (NSR) purposes. This facility-wide averaging provides the same emission reductions and does not result in any adverse impact on the net SOx emissions.
6. Previously Exempt or Previously Compliant Facilities
This provision is for facilities that are exempted from the present requirements of Rule 431.1 due to being a small source of SOx emissions (less than 5 lb/day as hydrogen sulfide). The provision also applies to facilities which are in compliance with sulfur limits but the gas quality changes such that in the near future a sulfur removal system is needed to comply with the limits. Without a compliance schedule in the rule, these facilities would be in violation the moment their SOx emissions exceed the exemption level or the gaseous sulfur levels exceed the compliance limit. The landfill and POTW operators requested an 18-month grace period from the date a facility is subject to the rule, to achieve compliance. The eighteen month period is estimated to be long enough to conduct engineering studies, budget/material procurement, construction, and compliance attainment. Staff, therefore, is incorporating this comment in the proposed amendment. Accordingly, monitoring, and reporting and recordkeeping requirements are also added consistent with the 18-month compliance period.
C. EXEMPTIONS
Facilities subject to the recently adopted SOx RECLAIM Rules which have their monitoring systems certified by AQMD, are no longer subject to the command-and-control rules, such as Rule 431.1. Refineries which produce refinery process gas as a by-product of the refining process, can burn or sell non-compliant fuel gas. In the case of sales gas, as long as the buyer is also subject to the RECLAIM rules, Rule 431.1 requirements do not apply. However, where a seller or a buyer of the non-compliant fuel gas is not subject to RECLAIM rules and therefore is subject to Rule 431.1, any transaction of non-compliant fuel gas would cause a violation. This is the case of Chevron, USA, a RECLAIM SOx facility, that sells non-compliant fuel gas to Southern California Edison, a non-RECLAIM SOx facility. According to the requirements of Rule 431.1, Edison cannot buy and burn refinery gas containing sulfur compounds in excess of the 40 ppm limit. Chevron claimed the sales gas as excess, which the refinery could not use; and if the gas is not allowed to be sold, Chevron would resort to flaring the gas without heat recovery, at the same time Edison would burn an equivalent amount of commercial natural gas.
Both Chevron and Edison have requested the AQMD to allow the sale of the non-compliant refinery gas to avoid flaring of the gas by Chevron and to provide Edison with cost savings which could be passed on the customers. The seller, in this case, Chevron, will account for any SOx emissions resulting from the burning of the sales gas as part of it's RECLAIM SOx emissions. Staff is now proposing to add an exemption to allow a non-RECLAIM SOx facility subject to Rule 431.1 to buy from or sell to a RECLAIM SOx facility any non-compliant fuel gas, provided that any increase in SOx emissions shall be accounted for in the RECLAIM facility's SOx allocations. No increase in SOx emissions is expected from this exemption, but rather, a net reduction in SOx emissions since all SOx emitted (not only that in excess of 40 ppm) from the burning of the sales gas shall be deducted from the RECLAIM facility's SOx allocation.
Edison is also buying refinery gas from its neighboring refineries, such as Mobil (for Edison's Redondo Beach facility) and Shell (for its Huntington Beach facility). These refinery gases, however, comply with the 40 ppm sulfur limit of Rules 431.1 and therefore will not be, at this time, subject to this exemption.
CONTROL TECHNOLOGY
The Los Angeles County Sanitation Districts, in cooperation with the members of the landfill industry, are conducting a study as part of the variance requirements, to determine cost-effective technologies to reduce sulfur contents in landfill gas. The study is focused on the commercial availability and applicability, process selectivity for H2S versus CO2, type of waste generated, and potential transfer of technology to landfill and/or sewage digester gases and cost effectiveness. The study is designed to control sulfur compounds in both landfill and sewage digester gases, and the sources of sulfur in the landfill environment. The Sanitation Districts had investigated the available sulfur control technologies world-wide. The study had identified seventy-eight (78) sulfur removal processes, of which eight (8) are considered for further investigation and pilot testing.
This study is required of the landfill facilities as part of the conditions provided with the variances. A complete listing of the available sulfur control technologies considered are listed in Appendix II.
A more detailed discussion of the control technologies that are being considered for further study are addressed below.
1. Liquid-phase Irreversible Reaction.
The process has several commercial names, such as, Enviro-Scrub, Sulfa Guard, Gas Treat 114, Sulfu-Rid, etc. The process consists of a reaction of an alkanolamine triazine, which selectively removes H2S from a gas stream containing CO2. The reaction products are in liquid form. The spent triazine is not regeneratable, but is analyzed to be nonhazardous and low in toxicity, which can be disposed in sewer. This process has been used in refineries and chemical plants, and as a gas sweetening agent at well sites.
2. Lo-Cat process
The Lo-Cat process is a liquid oxidation of sulfur in H2S by an iron catalyst (in ferric form) to produce an elemental sulfur. The elemental sulfur settles in the slurry which can be concentrated and removed from the bottom of the absorber. The reduced iron in the catalyst is regenerated by exposing to air, where oxygen oxidizes it back to the ferric form. The chemical reaction is shown below:
Absorption:
H2S(gas) + H2O(liq) <------> H2S(liq) + H2O(liq)
H2S(liq) <Ionization> 2H+ + S=
S= + 2Fe+++ <Oxidation> S + 2Fe++
Catalyst Regeneration:
1/2O2 + H2O + 2Fe++ < AIR > 2OH- + 2Fe+++
Overall Reaction:
H2S(gas) + O2(gas) -----> H2O + S
The LoCat process used at the Los Angeles City's Hyperion Sewage Treatment Plant, reduces sulfur levels to less than the 40 ppm limit. Occasionally, however, process breakdown occurs that would render the unit inoperational and the sulfur in the gas is carried in the gas stream uncontrolled.
3. Hiperion Process
The Hiperion process is a wet scrubbing process using naphthaquinone chelate catalyst. The process consists of a reaction of naphthaquinone with H2S, forming elemental sulfur. The hydroquinone chelate is then air-oxidized back to quinone chelate and water. The elemental sulfur is removed by filtration. The process can operate over a wide range of CO2 concentrations in the gas, however, the presence of CO2 lowers the H2S removal efficiency.
4. Carbon Adsorption Process
The carbon system consists of a catalytic action of activated carbon impregnated with a hydroxide (sodium, or potassium hydroxide), to promote oxidation of H2S to elemental sulfur. The activated carbon provides contact surface for H2S adsorption. The elemental sulfur is removed by solvent extraction and carbon is reused until its removal capacity is exhausted.
5. Iron Sponge
Iron sponge process is a dry bed oxidation using wood chips impregnated with hydrated iron oxide, Fe2O3, and sodium carbonate, Na2CO3, for pH control. The iron oxide reacts with hydrogen sulfide and oxygen in air, forming elemental sulfur, which remains in the sponge. The process, however, causes caking of the bed resulting in high pressure drop across the bed. The process removes hydrogen sulfide but not carbon dioxide. The main draw back in the process is that the used sponge is treated as hazardous and its disposal is tedious and costly. This process is now being used in fuel gas sweetening.
6. Sulfa-Treat
Like in iron sponge process, the process also consists of a reaction with iron oxide, Fe2O3 which, for this process, is coated on a granular material. Iron oxide reacts with hydrogen sulfide to form iron sulfide and water. The process is also used in sweetening of fuel gas.
7. Sulferox
Sulferox is a liquid based reduction-oxidation process using chelate. The process removes hydrogen sulfide and CO2, however, the only CO2 removed are those that are dissolved in the circulating solution. Similar to the Lo-Cat process, hydrogen sulfide is removed in the form of elemental sulfur. The spent solution is regenerated by exposing it to the air. This process has been used in the amine off-gas treatment, refinery process stream treatment, and Claus tail gas cleanup units.
8. Biofiltration
The process consists of a reaction of micro-organisms that convert hydrogen sulfide to sulfur compounds of higher oxidation state. Water is recirculated through the bioreactor to maintain proper moisture levels to provide nutrients and control the accumulation of metabolic products. Air is required for the biological oxidation reaction. The pH of the bioreactor is controlled by purging the circulation liquid with clean water.
EMISSION IMPACTS
The proposed amendments will result in a delay of SOx emission reductions, as well as potential SOx emission increases. There have already been emission reductions estimated to average about 0.25 ton per day foregone between May 4, 1994 and the present as a result of certain landfill facilities currently not complying with the 40 ppm total sulfur limit while operating under Hearing Board variances. These emission reductions will continue to be goregone through June 1997. Also, additional emission increases maybe expected as a result of the new monthly averaging period proposed in these amendments. The following is a more detailed discussion and quantification of the emission impacts.
A. Landfills
The significant issue in the proposed amendment which causes a delay in SOx emission reductions is the extension of the 40-ppm final compliance date for landfill gas to July 1997, with an interim limit of 150 ppm until final compliance. This proposal will allow landfill gas to be burned uncontrolled while facilities continue their study on the control technologies which have not been fully developed for landfill gas (and possibly for sewage digester gas).
There are 31 landfills identified in the AQMD survey, thirteen of which generate less than 5 lbs of sulfur as hydrogen sulfide, and as such, are exempted from the rule. A list of these landfills is included in Appendix III. The remaining 18 facilities generate about 150 million cubic feet of gas with sulfur levels ranging from 15 to 82 ppm. Ten of these facilities generate 81.5 MMCFD of fuel gas with sulfur levels above 40 ppm. These landfills are now operating under variance, until the end of 1995. The proposed extension of the compliance date for landfill gas could result in a maximum (theoretical) unattained SO2 emission reductions from these ten facilities of about 1.39 tons/day. This value is the difference between the existing limit of 40 ppm and the interim sulfur limit of 150 ppm until 1997. Based on the actual gas production and sulfur loading, however, the interim limit can result in an unattained actual SOx emissions of 504 lbs/day (0.25 ton/day) until final compliance date of July 1997. (It should be noted that the 0.25 ton/day SOx emission reductions foregone was based on hydrogen sulfide only and not total sulfur. For landfill gas, a correlation between H2S and total sulfur has not been established. Actual SOx emission reductions foregone would then be slightly higher than 0.25 ton/day). The interim limit of 150 ppmv is not expected to be exceeded and thus should also not achieve any interim emission reductions. The limit is added simply to provide a cap on the sulfur level until certain control technology is developed and applied for a particular facility.
The 200-ppm peak allowed for landfills choosing to use the monthly averaging also serves as a cap that, though possible, is not expected to be exceeded. Historical data show that the highest hydrogen sulfide concentration has been 112 ppm even during heavy rainfall. The total sulfur compound level, therefore, is not likely to reach the 200 ppm limit. The cap is proposed for landfill gas only to be consistent with the sewage digester gas, but is not expected to occur. Since there are no exceedances anticipated, thus, no SOx emissions increase is expected from this proposal.
B. Digester Gas
The extension of the averaging period for sewage digester facilities from 4 hours to daily is not expected to result in an increase in daily SOx emissions, but would provide operating flexibility and accommodate minor sulfur fluctuations during unit upsets. The peak concentrations of 500 ppm for digesters (with monthly averaging), will have a maximum potential single day SOx emission increase of 0.8 ton/day from the three POTWs. The 500-ppm peak, however, will only benefit facilities with post-gas generation control, such as the City of Los Angeles's Hyperion Unit, which has the Lo-cat unit to remove sulfur compounds from the gas stream. The Sanitation Districts of Los Angeles and Orange Counties are solely relying on the chemical additions upstream of and/or in the digesters. Any upsets in the system can be corrected by increasing or reducing the chemical injection, for which the response time is for several days. For POTWs, any upsets of more than two days with a peak of 500 ppm will result in a violation to the 40-ppm limit. For POTWs, therefore, the 500-ppm peak is only applicable to the Hyperion facility with the maximum potential single day SOx emission increase of 0.29 ton/day. Included in Appendix IV is a list of POTWs along with estimated capacities, gas production rates and H2S concentrations.
C. Small Refiners
The interim sulfur limit for small refiners was once incorporated in the rule requirements, but was inadvertently left out during the last amendment. The addition of the interim limit is to clarify enforceability and is not expected to result in any SOx emission reductions nor any emission increases.
D. Non-RECLAIM Facility Exemption
Based on the 1994 data on the subject fuel gas sold to Edison by Chevron El Segundo refinery, the proposed exemption to allow SOx RECLAIM facility to sell non-compliant fuel gas to non-RECLAIM facility, could result in a total increase in SOx emissions of 80 lbs/day (or 24.4 lbs SOx/day in excess of 40 ppm) at the non-RECLAIM facility. These increases, however, will be deducted from the seller's or buyer's RECLAIM allocation, as the case may be. Therefore, no net increase in SOx emissions is expected from the proposed exemption, but rather an emission reduction since the RECLAIM SOx facility is required to offset all (not only in excess of the 40 ppm) SOx emissions resulting from the burning of the fuel gas sold to a non-RECLAIM facility. Based on the 1994 data, the amount of gas subject to this exemption is averaged at 8.9 million cubic feet per day. At the current limit of 40 ppm sulfur, the net amount of SOx emissions that would be deducted from the seller's RECLAIM SOX allocation is about 60 lbs (0.03 ton) per day.
At this time it is not possible to anticipate the number of other non-RECLAIM facilities which may take advantage of this exemption. In order be able to sell this non-compliant gas, a pipeline transporting the gas from a seller to a buyer needs to be established, and applicable permitting and construction costs need to be considered.
E. Others
Other proposed changes are for formatting, clarification, and housekeeping purposes only, and no additional emissions increase or decrease is expected.
In summary the expected SOx emission reductions foregone due to certain landfills not complying with the 40 ppm total sulfur limit is estimated to be about 0.25 ton per day, and under hypothetical worst case scenario could be as high as 1.39 tons per day. The worst case SOx emission increases from the sewage treatment facilities due to monthly averaging provisions is estimated to be no more than 0.8 ton per day.
Therefore, the combined worst case emission impacts as a result of the proposed amendments could be as high as 2.19 tons per day of SOx. However, a more likely scenario would result in much lower excess SOx emissions in any one day. The air quality impacts associated with the proposed amendments are above the AQMD SOx significance threshold, and thus are considered to be significant. However, the proposed amendments facilitate the development of feasible and cost-effective gas desulfurization technologies, while providing increased flexibility and possible cost savings to the affected sources.
COMMENTS AND RESPONSES
The following summarizes comments received to date and AQMD staff's response to the comments. Responses to additional comments that maybe received on the proposed amendments, and the draft staff report will be included in the final staff report. Also all comments received on the Draft Supplemental Environmental Assessment (EA) will be responded to in the Final Supplemental EA.
A. EPA Region IX Comments
1. Comment: It is not clear whether CEMs will also be used to demonstrate compliance with the requirements of Section (c). This ambiguity is created by the language in Section (f) that reads, "The following test methods shall be used to determine compliance with the provisions of this rule." This language suggests that only the test methods will be used to satisfy the requirements of 40 CFR 60, Appendix F, when they are used for compliance determinations.
Response: The AQMD intends to use CEMS data for compliance, whenever such requirement is put into a regulation. AQMD does not consider CEMS to be a test method, but once certified as accurate and reliable against a "reference test method", the data derived from the CEMS is assumed to be as enforceable as that of the reference test method itself. A reference method is specified to determine compliance, however, the provision also allows for "any other method demonstrated by the applicant and approved in writing by the Executive Officers of the AQMD, and the ARB, and the Regional Administrator of the EPA". The CEMS, once approved and certified by the AQMD can be used as a tool to determine compliance. Rule language has been added to Section (d) to clarify this.
2. Comment: Sections (e)(1), (e)(2), and (g)(9). References are made to Sections (c)(4) and (c)(5), which are not in the rule. Also, in Sections (e)(3), should references be made to Sections (e)(1) and (e)(2) as opposed to Sections (d)(1) and (d)(2)?
Response: This appeared to be a typographical error in the proposed rule. The discrepancies have been corrected.
3. Comment: "Standard Conditions" should be defined.
Response: The term "standard conditions" had been in the rule for sometime, without being defined. Staff presumed that the term had been understood by the regulated public. To avoid presumption, however, the definition of the term is added.
4. Comment: Test Method 307-91 has not yet been deemed an acceptable method by EPA.
Response: Effective July 5, 1995 U.S. EPA Region IX has approved the March 1994 version of AQMD's Test Method 307-91 as an acceptable, alternative, California test method..
B. Public Comments
1. Comment: The definition of "monthly weighted average sulfur content" is confusing. The definition could also have a profound impact on the Sanitation Districts alternative monitoring plan submitted in 1992. It would require the Sanitation Districts and other POTW and landfill operators to monitor fuel sulfur at least daily.
Response: The weighted average value for sulfur is necessary to determine a more accurate SOx emissions over time where gas production rate is not constant. For landfills and sewage digesters, however, production rates are virtually constant, considering a slow and steady bacterial action. Where gas production rate is constant, the weighted average is the same as the average (arithmetic mean) sulfur content of the gas. To minimize any unnecessary burdens and to avoid confusion about the term, facilities subject to the rule other than refineries and electric utility generating outfits, may use the arithmetic mean in calculating SOx emissions.
2. Comment: As subparagraph (c) and (d) are written, landfills currently exempt from the requirements of Rule 431.1 could find themselves immediately in violation of the rule if fuel sulfur increases uncharacteristically above rule requirements or an annual source test indicates Rule 431.1 applicability. Commenter asked for a compliance schedule to allow time for these new facilities to achieve compliance.
Response: To accommodate cases where facilities that used to be exempt from the rule and eventually exceed the exemption category, staff proposes to add a provision to provide time for such facilities to achieve compliance. The eighteen-month compliance period is proposed to allow for engineering, procurement, installation, and operation to achieve compliance.
3. Comment: Subparagraph (d)(1) requires that facilities "...install gaseous fuel monitor to determine the sulfur content of the gaseous fuel ..." The requirement implies that facilities shall install continuous monitors immediately upon rule amendment. There must be an interim period to accommodate the purchasing and installation of such a unit.
Response: Facilities that expand or upgrade operation, or merge smaller operations can fall under this situation. Considering that these landfill and sewage digester facilities are owned and operated by local agencies, procurement and installation could pose a problem. Staff, therefore, proposes to allow 18 months of procurement and installation prior to compliance.
4. Comment: With respect to annual reporting, all facilities currently submit annual emission inventories to the AQMD including the total oxides of sulfur emissions. Landfill operators also submit quarterly Rule 1150.1 reports detailing the sulfur content of the landfill gas. For facilities choosing continuous monitors operating under requirements of Rule 218, monthly reports of the sulfur content must be submitted. The need to submit another report describing information already provided to the AQMD is an inefficient use of resources.
Response: The requirement was added to the rule to make any reporting an official requirement. AQMD does not intend to duplicate any reporting that is already in practice. If a facility is already submitting the report which includes all of the required information to the AQMD, no additional reporting is expected to comply with the rule requirement.
5. Comment: The Sanitation Districts are currently complying with Rule 431.1 at the Joint Water Pollution Control Plant (JWPCP) by increasing the quantity of ferrous chloride added to the digesters. However, long term effects of such high doses of ferrous chloride on digester performance are still unknown. High doses of ferrous chloride could lower the alkalinity of the digesters or negatively impact the final sludge compost product because of a higher iron salt content in the sludge.
Response: There are several other sulfur removal technologies that are considered for biogas application. If increased dosage of ferrous chloride poses an adverse impact on the process or the by-product, the pilot study may lead to another alternative sulfur control method.
6. Comment: In search for cost-effectiveness, the Sanitation Districts request allowance of emissions averaging option for a facility with multiple fuel gas usage points as a means of complying with Rule 431.1. It is more cost effective for the facility to reduce sulfur in 80% of total gas production down to 25 ppm and the 20% to 100 ppm, than to reduce 100% to 40 ppm. The averaging method is expected to result in the same emission reductions as the centralized system.
Response: The County Sanitation Districts of Los Angeles burns all sewage digester gas it produces in one facility, but its fuel gas system is not distributed from one central point. Staff agrees that the two scenarios cited above are equivalent to each other by which, allowing the County Sanitation Districts to apply a facility-wide averaging system would result in the same SOx emission reductions. A provision is incorporated in the proposed rule amendment to address the issue.
7. Comment: Subparagraph (c)(3) indicates that landfill gas (LFG) sulfur averaging period is daily. Does this mean that a sample has to be collected over a one day period for analysis of total sulfur content in the LFG?
Response: The requirement for daily averaging can be interpreted that an integrated sample for the entire period is needed. For landfills and POTWs, however, a continuous sulfur monitor is yet to be developed. In the mean time, AQMD may consider an alternative monitoring system to be acceptable. A guideline for approval of alternative fuel monitoring system (CFMS) has been included as an addendum to the proposed amendment of the rule. The proposed daily averaging provides additional flexibility to the plant operators, compared to the existing 4-hour averaging requirement. If sampling to comply with the existing requirement has been complied with, there should be no reason not to be able to comply with the daily average.
8. Comment: Subparagraph (c)(3): An eighteen months transition period, without requiring costly rule variance, should be allowed for facilities that, in the past, showed sulfur limits below those listed in Table 1 but have exceeded them since then. This period should be used for evaluation of various sulfur-reducing technologies available, selection of a particular process, procurement, delivery, installation, and trouble-shooting prior to bringing on-line.
Response: Facilities that are now under the 5 lbs/day exemption, may increase their gas production or change the operating parameters to alter fuel gas quality such that the total sulfur compounds in the gas produced exceeds the exemption level. These facilities are then subject to the sulfur limits of the proposed rule. To bring into compliance, these facilities need to have engineering design, procurement, installation, normalizing operation prior to compliance. Staff proposes to add a provision to address the issue.
9. Comment: Subparagraph (d)(1): Will the Executive Officer of the AQMD approve alternative monitoring methods on a case-by-case basis, or SCAQMD pursues CARB and EPA Region IX's approval.
Response: AQMD staff has reviewed POTWs' alternative monitoring system. In this case, the alternative system was submitted to the AQMD by the group of POTWs. When deemed approvable, the AQMD endorsed the system to ARB and EPA for approval. AQMD plans to do the same for any other POTW or landfill facilities. In order to have a consistent methodology for reviewing these alternative plans, a guideline is incorporated as an attachment in the proposal.
10. Comment: Subparagraph (d)(1): As a public agency, Orange County Integrated Waste Management Department has to publicly advertise "Invitation to Bid" for analytical services lab contracts. We understand that ATMAA, Inc. in Chatsworth is the only SCAQMD-certified lab to perform Method 307-91. Contracting with ATMAA labs is not a practical option to the Department, given the fact that some of our landfills are located as far south as San Clemente/San Juan Capistrano area.
Response: The AQMD has the capability to conduct Test Method 307-91 for a fee specified in Rule 304. AATMA has applied for an equivalent method to 307-91, but still awaiting approval by the AQMD. AQMD understands that CORE Labs in Long Beach also intends to pursue AQMD approval for Method 307-91.
11. Comment: Attachment A(1): Does a continuous monitor have to monitor and record all sulfur compounds that may be present in the gaseous fuel? Please clarify.
Response: Rule 431.1 requires a maximum concentration of total sulfur compounds in the gaseous fuel, which includes hydrogen sulfide, all mercaptans, carbonyl sulfide, organic sulfides, and disulfides. The continuous fuel monitoring system is expected to monitor and record the total sulfur in the fuel gas, however, no such monitor has yet been developed for biogases, which have high moisture and carbon dioxide contents.
12. Comment: How often should the calibration drift test be performed? Please clarify 6 out of 7 test days.
Response: The requirement for calibration drift has been removed from the proposal.
13. Comment: The definition of "stream day" is confusing and should be clarified. For example, should a facility calculate sulfur content if a process unit (digester) works? What if the facility operation does not burn its produced digester gas but stores it instead?
Response: The term "stream day" is used in Rule 431.1 definition of "small refiner". The term does not apply to sewage digester or landfill facilities.
14. Comment: (e)(1) County Sanitation Districts of Orange County (CSDOC), as well as other facilities, submit annual emission inventory reports containing information about sulfur oxide (SOx) emissions. It is not understood why the duplication of this information is necessary and required in this section.
Response: If the facilities are already reporting to the AQMD information specified in Rule 431.1, such reporting should suffice for compliance with the rule. No additional reporting will be necessary.
15. Comment: (g)(10) A facility that burns gaseous fuel purchased from RECLAIM facility within SCAQMD's jurisdiction, should not have to obtain or submit any information regarding compliance or non-compliance of the purchased fuel. It should be assumed that the facility selling the gaseous fuel would be responsible for violating Rule 431.1 if non-compliance was found. CSDOC buys natural gas from the Gas Company for our engines and we assume that the sulfur content of the gas does not exceed 16 ppm.
Response: Rule 431.1's requirement for natural gas is not the same as for other gaseous fuels. For natural gas, the burden of proof is from the utility company that supplies the gas. Section (c)(1) of the rule states that "a person shall not sell or offer for sale for use in the AQMD natural gas containing sulfur....". Natural gas is virtually free of any sulfur compounds, with a trace of mercaptans added only for odor detection. Natural gas consumers do not have control over the quality of gas they receive from the utility company. For other gaseous fuels, such as, refinery gas, landfill gas, sewage digester gas, and process gas which are produced with inherently higher sulfur compounds, the sulfur level of gas dePacific Energyds on the efficiency of the sulfur removal system employed. Gas consumers should be aware of the quality of the gas they burn other than pipeline quality natural gas. These gaseous fuels are alternative to natural gas. Gas consumers have to choose these gases over natural gas, and gas quality should be a factor to consider in addition to cost and availability.
16. Comment: CSDOC incurred extremely high cost to comply with Rule 431.1 requirements. Since 1994, when the 40 ppm sulfur limit was effective, CSDOC achieved compliance with the new requirement by increasing the amount of iron salt (ferrous chloride) added to the digester by four times. Besides the unknown effect of such high doses on long term digester performance and both sludge and digester gas quality, the high price of chemicals alone (not counting additional monitoring requirement) doubled CSDOC's cost of compliance to $16,000/ton of sulfur removed. Taking into consideration that the total amount of SOx emitted by our plants and by all POTWs in the basin is insignificant, we suggest SCAQMD staff to once more consider the possibility of increasing the sulfur concentration limit in digester gas to 60 ppm, as we proposed in 1990 when the current 40 ppm limit was established.
Response: Rule 431.1 is one of the technology-forcing rules of the AQMD. Current practice already proved technology to be available and feasible. Staff, therefore, cannot raise the sulfur limit, instead a monthly averaging is proposed as an option, as long as a continuous monitor is installed and operating.
17. Comment: The City of Los Angeles' Hyperion Treatment Plant has submitted a hydrogen sulfide monitoring plan which was approved by the South Coast Air Quality Management District. The plan calls for daily samples to be collected and the City has shown that hydrogen sulfide concentrations do not vary significantly during the day.
Beginning in 1985 with the Stretford process and followed in 1994 by the LoCat process, the City of Los Angeles' Hyperion Treatment Plant has invested significant capital in hydrogen sulfide removal technologies. Given a $250,000/yr credit for reductions in upstream ferrous chloride additions, this equates to a cost of $3556 per ton of sulfur removed (based on 500 ppmv inlet hydrogen sulfide concentration, 95% removal efficiency, and 12 MMCFD digester gas flow). The Lo-Cat process resulted in a cost effectiveness of "$3556 per ton of sulfur removed". The chemical (ferrous chloride) addition translates to an incremental cost of "$2877 per ton of sulfur removed". For the present gas production of 7.5 MMCFD, the overall cost effectiveness becomes $8568/ton. The initial staff report prepared by the SCAQMD estimated such cost at around $900/ton.
Response: Staff's cost analysis in 1990 showed that iron sponge process used by Eastern Municipal Water District (EMWD) had a total capital investment of $33,000. The facility's gas production was 130,000 CFD at 1400 ppm H2S with a removal efficiency of 90%. The iron sponge process was calculated to have a cost effectiveness of $920/ton of SOx removed. Staff's cost information was provided by the facility, and was based on actual values. The City of Los Angeles' Hyperion facility produces 7.5 MMCFD with an initial sulfur loading of 500 ppm. The City should not expect to translate the same cost effectiveness directly into its own facility, as its digester operation is an order of magnitude bigger than the EMWD. Besides, the cost effectiveness is expressed in $ per ton of SO2 removed and not $ per ton of sulfur. The cost effectiveness of the former is half as much as the latter. So, if the City has determined that the cost is $8568 per ton of sulfur removed, the cost effectiveness should be $4284 per ton of SO2. This value is within the range of cost effectiveness reported in 1990.
18. Comment: The City of Los Angeles requested that the averaging period be changed from 4 hours to monthly. "A longer averaging period strikes a balance between the District's requirements to cut SOx emissions in the basin and the City's need to control the very slow moving anaerobic digestion process in a cost effective manner."
Response: Staff realized that the City's Lo-Cat unit is efficient in removing sulfur compounds from the fuel gas so long as it is operating normally. On some occasions, however, the unit was found to be less effective, causing the sulfur level to exceed the limit. Also, if the unit breaks down, the sulfur level remains uncontrolled at about 500 ppm. To minimize the chances of violating the sulfur limit, staff proposes as an alternative, a monthly averaging of the same 40 ppm level provided a continuous monitor is installed and operating.
19. Comment: Considering the current state of the technology, Waste Management Recycling and Disposal Services of Southern California (WMRDSC) do not feel that an adequate amount of time is given for compliance with the final limit. "Extending the final compliance date for landfills to July 1, 1998, will give more time for the technology to catch up, and for the budgeting, design, permitting, and installation of the required sulfur control equipment. We would also like to see language added to the rule which would provide facilities relief from the final compliance limit if a viable control technology is not identified within 6 months of the final compliance date."
Response: The proposed July 1, 1997 final compliance date was coordinated by AQMD staff with the group of landfill operators led by the Sanitation Districts of Los Angeles County. Staff suggest that WMRDSC should work with the Sanitation Districts regarding final compliance date.
20. Comment: A continuous monitoring system for total sulfur in gaseous fuel is not yet available in the market. If the Rule is amended now, landfills would not be able to comply with the monitoring requirement. "Any monitoring method other than a continuous fuel gas monitor capable of measuring total sulfur would require approval by the CARB and EPA. District staff does not have a commitment from either agency to issue decisions on the alternative methods within a given time frame. The current rule language forces the landfills into a position of indefinite noncompliance. Facilities would be required to have variance coverage for the period of time needed to obtain CARB and EPA approval." The company requested that CARB and EPA shall not be involved in the monitoring system approval.
Response: AQMD staff reviews the monitoring system submitted by the industry. When the system is deemed acceptable, staff will endorse it to CARB and EPA for approval. AQMD staff, however, cannot guarantee a timely response from the two agencies. Either ARB or EPA cannot be excluded from the review and approval process of the alternative monitoring system. Since this provides for an alternative means to comply with the requirements of the rule subject to the AQMD Executive Officer approval, CARB and EPA have in the past requested to be involved in such approval process. However, the AQMD staff will attempt to expedite these approvals, as we have already received CARB approval on one alternative monitoring plan.
21. Comment: Staff proposes to exempt non-RECLAIM SOx facility burning noncompliant gas purchased from a RECLAIM SOx facility provided that both the RECLAIM SOx and the non-RECLAIM SOx facilities report to the AQMD the amount of subject gas burned. Concerned of double counting emissions, SCE requests amendment of paragraph (g)(10)(A) such that reporting and SOx emission accounting would be attributed only to the RECLAIM SOx facility.
Response: Staff now propose that non-RECLAIM SOx facility reports the quantities and daily averages of the sulfur contents of the gaseous fuel sold or purchased and burned. Pursuant to the present Rule 431.1(c)(2), SCE is required to report monthly to the AQMD its daily fuel gas consumption along with the information stated above. The RECLAIM SOx facility, on the other hand, is proposed to report all the SOx generated from the burning of the subject fuel as part of its overall SOx emissions. The non-RECLAIM SOx facility does not have to report any SOx emissions generated from the subject fuel, so any double counting is not expected to hapPacific Energy.
22. Comment: The term "instantaneous" that is inserted in the table needs to be defined. Some recording devices can provide a 15-minute average, while others 1-minute.
Response: The term "instantaneous" as used in the rule means that the sulfur analysis is done from a grab sample obtained according to the sampling procedure. For example, if the procedure calls for a 15-minute sampling, "instantaneous" would mean 15 minutes. If a continuous monitor is used, any peak reading on the chart will be considered instantaneous. The language has been changed accordingly.
23. Comment: The rule specifies a 4-hour averaging period. Is this a 4-hour block as in 6 averages per day, or a rolling average? In the case of a rolling average, does the clock start at the top of every hour, or every 15-minutes as implied by Rule 218?
Response: Any monitoring requirement in Rule 431.1 shall be consistent, as much as possible, to Rule 218.
24. Comment: The rule states that compliance is determined by utilizing SCAQMD Method 307-91. It is believed that this method is a source test methodology, not suitable for a continuous fuel gas monitor (CFGM) or CEMS. In any event, there is no appropriate language in the proposal to designate the CFGM or CEMS data as enforceable.
Response: A language is added to the rule proposal to the effect that the continuous monitoring data shall be used for compliance after the continuous monitor is certified by the AQMD.
25. Comment: As amended during the April 28 workshop, the span value of the CFGM shall be so that all readings fall between 20 and 95% of scale. Table 1 has an instantaneous limit of 800 ppm, and a 4-hr average of 40 ppm, and 20% of 800 or 160 ppm, is four times the 40 ppm limit.
Response: The CFGM or CEMS requirement was intended for enforcement of the 40 ppm limit and not the 800 ppm.
26. Comment: There was discussion at the April 28 Workshop covering the reporting requirements of Rule 431.1 versus Rule 218. Considering that Rule 431.1 has its own set of performance standards for CFGM and CEMS, shouldn't there be a direct link between the two?
Response: A language referencing Rule 218 requirements was added in Section II of Attachment I to this effect.
27. Comment: The averaging period for the 40 ppm limit should be changed to weekly. As required by the Hearing Board during the variance hearing, Pacific Energy submitted extensive data between May 1994 and February 1995 of the daily colorimetric and monthly analytical data. The data show that the composition of the landfill gas does not change radically over a short period of time. Rather, the gas composition is very stable. Any changes in gas composition occur slowly. Based on this data, the Hearing Board granted the company's request to conduct weekly colorimetric and monthly analytical testing. A weekly averaging period should be sufficient to determine compliance with the rule.
Response: Due to a number of requests to change the averaging period, staff proposed an alternative to daily averaging, that is, a monthly averaging provided that a continuous monitor is used to determine compliance. Also a different frequency of sampling other than daily could be approved on a case-by-case basis.
28. Comment: Pacific Energy believes that the 40 ppm limit is an inordinate burden that landfill operators are facing. "Landfill gas recovery operations are performing an essential public service. Further, these operations are mandated by other District rules to control gas emissions from the landfill. Since landfill gas represents less than 1% of the total fuels burned in the District, Pacific Energy does not understand the need for such strict controls. A compliance limit of 100 ppm would allow the District to realize emission reductions while relieving landfill operators from some of the enormous capital expenditure we face."
Response: Staff realized that the landfill industry, headed by the Sanitation Districts, is still looking at a technology to control sulfur dioxide emissions from the burning (or disposal) of landfill gas. Because of this ongoing study, staff proposed a compliance extension until July 1997, and provide an interim limit of 150 ppm averaged daily. In addition, an optional monthly averaging provision has been added to provide additional flexibility to the facility operators.
DRAFT SOCIOECONOMIC ASSESSMENT
Proposed Amended Rule 431.1 contains four amendments with potential socioeconomic effects. First, an interim sulfur content limit is proposed for small refiners. The interim limit would take effect upon rule adoption and would last until May 4, 1996, the compliance date of the permanent limit in existing Rule 431.1. The interim limit was in the previous rule version, but was inadvertently omitted during the last rule amendment. This interim limit is not expected to result in any SOx emission reductions, since the small refiners already meet the interim limit. The interim limit is also not expected to cause a cost impact on small refiners. The interim limit is needed to clarify rule enforceability.
Second, an extension in the compliance deadline for landfill facilities from May 4, 1994 to July 1, 1997 is proposed. The extension will allow time for the development of control technologies for sulfur removal in landfill gas.
Third, an exemption is proposed to allow SOx facilities in the Regional Clean Air Incentives Market (RECLAIM) program to sell non-compliant fuel gas to non-RECLAIM facilities, or to purchase non-compliant fuel gas from the non-RECLAIM facilities, so long as the excess SOx emissions are reported by the RECLAIM facility and accounted for under the RECLAIM program. The excess SOx emissions are calculated based on PAR 431.1's SOx limits. This amendment will allow more flexibility to these sources and, thus, is expected to provide an economic benefit to them.
Fourth, it is proposed that the averaging period for sulfur compound limits be increased for landfill and sewage digester gases from 4 hours to daily. In addition, an option to choose monthly averaging and/or to demonstrate compliance in the aggregate within a facility, rather than at each piece of equipment is proposed for landfills and sewage treatment, ("Publicly Owned Treatment Works" (POTWs)) plants . These changes provide increased flexibility to facility operators in responding to upset conditions, and are expected to reduce the cost of control.
A. Affected Industries
There are 31 landfills (Standard Industrial Classification (SIC) 4957) and 22 POTWs (SIC 4952) in the district. All of these facilities are subject to existing Rule 431.1 and would be subject to the proposed amendments to Rule 431.1. Refineries are in SIC 2911, Petroleum Refining . Small refineries, which are generally those with a crude oil capacity of not more than 55,000 barrels per day, are subject to Rule 431.1. Large refineries (generally ones which have a crude oil capacity over 55,000 barrels per day), which are in the RECLAIM program, are generally not subject to Rule 431.1, once they have compiled with their RECLAIM monitoring requirements. They are, however, subject to section (g) of Rule 431.1 if they sell or purchase non-compliant fuel gas.
B. Impact on Employment and the Economy
The proposed amendments to Rule 431.1 are not expected to impact the economy and employment negatively. As described in the "Range of Costs" section below, the amendments are not expected to increase control costs, but could result in cost savings to affected facilities.
C. Range of Costs
The proposed amendments to Rule 431.1 are not expected to increase control costs compared to the existing rule. PAR 431.1's interim sulfur content limit for small refineries can be met using control equipment presently in place, with no additional operational expenditures. The extended compliance deadline for landfills will provide additional time for the development and operation of pilot plants for demonstrating and testing candidate control technologies. The proposed exemption to allow Sox RECLAIM faciliities to sell non-compliant fuel gas to or buy non-compliant fuel gas from non-RECLAIM facilities is expected to provide an economic benefit otherwise not available to these facilities.
The proposed changes in the averaging periods for measuring sulfur compounds are expected to provide potential economic benefits to landfills and POTWs, through reduced operational costs for controls already in place. The first of these changes increases the allowable averaging period for sulfur compound limits for landfill and sewage digester gases from 4 hours to daily. It is also proposed that landfills and POTWs be provided the option of further lengthening the averaging period for sulfur compound limits to one month. A "bubbling" provision which would allow facilities to demonstrate compliance with the sulfur limits of Rule 431.1 in the aggregate within a facility, rather than at each piece of equipment, is also being proposed. The "bubbling" provision could result in a cost savings to facilities who choose to apply for its use and approval.
D. Alternatives, Emission Reduction Potential, and Necessity of Rule Amendment
A discussion of alternatives to the proposed amendments is contained in the Environmental Assessment. There is no emission reduction potential associated with the proposed amendments as discussed in the Staff Report. As a result, the proposed amendments are not needed to attain ambient air quality standards.
E. Rule Adoption Relative to the Cost-effectiveness Schedule
On October 14, 1994, the SCAQMD Governing Board adopted a resolution that requires staff to address whether proposed rules being considered for adoption are in order of cost-effectiveness as defined in the 1994 AQMP. Cost-effectiveness is analyzed with respect to cost per mass of emissions reduced. PAR 431.1 is not scheduled for amendment in the 1994 Air Quality Management Plan. The proposed revisions to Rule 431.1 also involve no emissions reductions. PAR 431.1, therefore, is not ranked by cost-effectiveness.
CHAPTER II
P R O P O S E D A M E N D M E N T S
CHAPTER III
C O N T R O L T E C H N O L O G Y A S S E S S M E N T
CHAPTER IV
E M I S S I O N I M P A C T S
CHAPTER V
C O M M E N T S a n d R E S P O N S E S
CHAPTER VI
D R A F T S O C I O E C O N O M I C A S S E S S M E N T
A P P E N D I X I
T I M E S C H E D U L E F O R G A S
D E S U L F U R I Z A T I O N T E C H N O L O G Y R E V I E W
A P P E N D I X II
L I S T O F G A S D E S U L F U R I Z A T I O N
T E C H N O L O G I E S C O N S I D E R E D
A P P E N D I X III
S U R V E Y O F S C A Q M D L A N D F I L L S L I S T
A P P E N D I X IV
S U R V E Y O F S C A Q M D P O T W S L I S T
A P P E N D I X V
P R O P O S E D L A N G U A G E F O R A M E N D E D
RULE 431.1
(Adopted November 4, 1977)(Amended September 1, 1978)
(Amended February 2, 1979)(Amended January 8, 1982)(Amended May
6, 1983)
(Amended May 4, 1990)(Amended April 5, 1991)
(September 11, 1992)(October 2, 1992)
(PAR4311H - July 27, 1995)
PROPOSED AMENDED RULE 431.1. SULFUR CONTENT OF GASEOUS FUELS
(a) Purpose and Applicability
The purpose of this rule is to reduce sulfur oxides (SOx) emissions from the burning of gaseous fuels in stationary equipment requiring a permit to operate by the South Coast Air Quality Management District (District).
(b) Definitions
(1) BURN means to combust any gaseous fuel, whether for useful heat or by incineration without heat recovery, except for flaring of emergency vent gases.
(2) CONTINUOUS EMISSION MONITORING SYSTEM (CEMS) is a system of equipment that continuously measures and records all parameters necessary to directly determine mass emissions of pollutants, and which meets all the requirements of Attachment A, Section II.
(3) CONTINUOUS FUEL GAS MONITORING SYSTEM (CFGMS) is a system of equipment that continuously measures and records total sulfur concentration in the gaseous fuel prior to burning, and which meets all the requirements of Attachment A, Section I.
(4) DAILY AVERAGE is an arithmetic mean of all the sulfur compounds readings within a calendar day obtained according to the guideline specified in Attachment A.
(5) EMERGENCY VENT GAS is any gas released from a process unit as a result of any process upset or breakdown.
(2 6) GASEOUS FUELS is
any gaseous material which releases heat when burned include
including, but are not limited to, any
natural, refinery, process, synthetic,
landfill, sewage digester, or waste gases with
a gross heating value of 2670 kilogram calories per cubic meter
(300 BTU per cubic foot) or higher, at standard conditions.
(3 7) LANDFILL GAS is any gas derived
through any biological process from the decomposition of organic
waste buried within a waste disposal site.
(8) MONTHLY WEIGHTED AVERAGE SULFUR CONTENT is the result of the summation of average daily sulfur contents of the fuel(s) consumed multiplied by the average daily consumption rates of the fuel(s) consumed in any month divided by the total gaseous fuel consumption rate for that month.
(4 9) NATURAL GAS is a mixture of gaseous
hydrocarbons, with at least 80 percent methane (by volume), and
of pipeline quality, such as the gas sold or distributed by any
utility company regulated by the California Public Utilities Commission.
(10) RECLAIM SOx FACILITY is a facility that has been included in the RECLAIM (Regional Clean Air Incentives Market) program in accordance with the requirements of Rule 2001 "Applicability", and/or which has been issued a RECLAIM Facility Permit and is subject to the requirements of Rule 2011, "Requirements for Monitoring, Reporting, and Recordkeeping for Oxides of Sulfur (SOx) Emissions".
(11) REFINERY GAS is any combustible gaseous by-product generated from a petroleum refinery process unit operation, with a gross heating value of 2670 kilogram calories per cubic meter (300 BTU per cubic foot) or higher, at standard conditions.
(5 12) SEWAGE DIGESTER GAS is any
gas derived from an anaerobic decomposition of
organic sewage within its containment.
(6 13) SMALL REFINER means any refiner
who owns or operates a refinery person
owning or operating a facility in California that produces
materials from processing of petroleum crude provided
such facility:
(A) has and at all times had since January 1, 1978, a crude oil capacity of not more than 55,000 barrels per stream day; and
(B) has not been, at any time since September 1, 1988, owned or controlled by any refiner that at the same time owned or controlled refineries in California with a total combined crude oil capacity of more than 55,000 barrels per stream day; and
(C) has not been at any time since September 1, 1988, owned or controlled by any refiner that at the same time owned or controlled refineries in the United States with a total combined crude oil capacity of more than 137,500 barrels per stream day; and
(D) has received a two-year extension for compliance with California Air Resources Board's Phase II Reformulated Gasoline Requirements.
(14) STANDARD CONDITIONS is the atmospheric state where the temperature is 60oF and barometric pressure is 14.7 pounds per square inch absolute.
(15) STREAM DAY is any day or part of a day when a facility or a process unit is in operation.
(b c) Sulfur Content Requirements
(1) Until May 4, 1994:
(A) A person shall not sell any gaseous
fuel containing sulfur compounds in excess of 80 ppm (parts per
million) calculated as hydrogen sulfide except landfill gas or
sewage digester gas.
(B) A person shall not sell landfill
gas or sewage digester gas containing sulfur compounds in excess
of 250 ppm calculated as hydrogen sulfide.
(C) A person shall not burn or discharge
to any fuel gas system or vent gas disposal system, gaseous fuel
containing sulfur compounds in excess of 800 ppm calculated as
hydrogen sulfide, unless sulfur compounds in the stack gases are
reduced to a level below that which would be emitted when using
a fuel which complies with the requirements of this subparagraph.
For purposes of this subparagraph, the 800 ppm limit shall
apply to the gaseous fuel as vented from a process unit or, if
applicable, as vented from a sulfur removal unit.
(1) Natural gas
(2) On and after May 4, 1993, a
A person shall not sell or offer for sale for use in
the jurisdiction covered by the District natural gas containing
sulfur compounds in excess of 16 ppm calculated
as parts per million by volume (ppmv) calculated as
hydrogen sulfide.
(2) Small Refiners Refinery gas
Before May 4, 1996, a small refiner shall not burn or discharge to any fuel gas system or vent gas disposal system, refinery gas containing sulfur compounds in excess of 800 ppmv calculated as hydrogen sulfide, unless sulfur compounds in the stack gases are reduced to a level below that which would be emitted when using a fuel which complies with the requirements of this paragraph. For purposes of this paragraph, the 800 ppmv limit shall apply to any gaseous fuel vented from a process unit or, if applicable, as vented from a sulfur removal unit.
On or after May 4, 1996 the applicable sulfur compounds content limit for small refiners refinery gas is as specified in paragraph (c)(3) of this rule.
(3) Other Gaseous Fuels
On and after May 4, 1994, except for small refiners,
On or after the applicable compliance dates specified in Table
1, a person shall not burn, purchase, sell,
or offer for sale for use in the jurisdiction of the District,
any gaseous fuel containing sulfur compounds calculated as
ppmv hydrogen sulfide, in excess of the concentration limits
as measured over the averaging periods for various gaseous fuels
as specified in Table 1 40 0ppm, averaged over any
consecutive 4-hour period, and calculated as
parts per million by volume hydrogen sulfide.
TABLE 1
Fuel Type Sulfur Limits Averaging Compliance Date
ppmv Period On or After
Refinery Gas
Small Refiners 40 4 hrs May 4, 1996
Other Refiners 40 4 hrs May 4, 1994
Landfill Gas 150 Daily Adoption Date
40 or Daily or July 1, 1997
40/200 Monthly/
15-minutes July 1, 1997
Sewage Digester Gas 40 or Daily or May 4, 1994
40/500 Monthly/- Adoption
15-minutes date
Other Gases 40 4 hrs May 4, 1994
(A) Landfill gas and sewage digester gas
(i) A person who complies through monthly averaging shall install and properly operate a continuous monitor that complies with the requirements specified in subdivision (d) of this rule. An instantaneous reading shall be that reading obtained from the approved CFGMS or as calculated from the approved CEMS reading.
(B) Optional Facility Compliance Plan (OFCP)
A person may achieve compliance with paragraph (c)(3) by achieving equivalent sulfur dioxide (SOx) emission reductions within the facility, provided that the applicant submits and complies with an Optional Facility Compliance Plan (OFCP) approved in writing by the Executive Officer. The OFCP shall:
(i) Contain, at a minimum, all data, records, and other information necessary to determine eligibility for alternative emission control, including but not limited to:
(I) A list of equipment and a description of the equipment where the gaseous fuel is being produced and/or burned;
(II) Amount of fuel produced by and/or to be burned in each of the equipment listed above;
(III) The estimated emission of sulfur dioxide from each equipment;
(IV) Historical and projected information on fuel usage;
(ii) Demonstrate that daily total SOx emissions under the OFCP from all sources within the facility regulated under Rule 431.1 would be less than or equal to SOx emissions that would have been emitted based on actual total SOx emissions from each source, or the sulfur content limits of this rule, whichever results in lower SOx emissions. The total SOx emissions generated from the subject fuel shall be determined using a continuous emission monitoring system (CEMS) specified in subdivision (d). The total emissions may be determined by monitoring the sulfur dioxide emissions from at least 80 percent of the total fuel gas consumed as obtained from a totalizing meter, and calculating the total emissions using the CEMS data;
(iii) Demonstrate that the permit units subject to the specified rule emission limitations are in compliance with all applicable District rules or are on an approved schedule of compliance; and
(iv) Demonstrate that continuous monitoring requirements of SOx emissions specified in subdivision (d) of this rule are complied with.
(4) Regardless of the provisions of subparagraph
(b)(1) or (b)(2) of this rule, a person may sell any gaseous fuel
provided that:
(A) The gaseous fuel is delivered directly
to a sulfur removal unit which reduces the sulfur content to no
greater than the limits specified in subparagraph (b)(1) or (b)(2),
as applicable; and
(B) The seller notifies the Executive
Officer prior to any such sale of the quantity, heat value, and
composition of the gaseous fuel to be sold; and
(C) The buyer has an approved Permit
to Construct and/or Permit to Operate for the sulfur removal unit
that will be used to treat the purchased gas.
(5) No later than May 4, 1994, a person
burning gaseous fuel other than natural gas in permitted stationary
equipment shall install a continuous emission monitor as approved
by the Executive Officer, or provide an alternative method that
is demonstrated to be equivalent to the satisfaction of the Executive
Officer and the Air Resources Board (ARB) and the Regional Administrator
of the Environmental Protection Agency (EPA), Region IX, to determine
the sulfur content of the gaseous fuel prior to its use in a combustion
process. An application for approval of such a device or an alternative
method shall be submitted to the Executive Officer no later than
May 4, 1992.
(6) No later than May 4, 1994, except
for small refiners, a person burning petroleum refinery gases
in District permitted stationary equipment shall install a continuous
gaseous fuel monitor or a stack continuous emission monitoring
system (CEMS), as approved by the Executive Officer, to determine
the sulfur content of the gaseous fuel prior to burning. If a
stack CEMS is installed, a person shall:
(i) Not mix petroleum refinery gases
with natural gas, propane or other gaseous fuels upstream of the
monitoring location;
(ii) Meet all criteria specified by the
Executive Officer including, but not limited to, those in Attachment
A of this rule for stack CEMS no later than May 4, 1993.
(iii) Apply for Executive Officer approval
of a stack CEMS no later than May 4, 1993.
(7) The person burning gaseous fuel or
petroleum refinery gas is exempt from the requirements of paragraphs
(b)(5) and (b)(6) if such person demonstrates to the satisfaction
of the Executive Officer that the supplier of the gaseous fuel
or petroleum refinery gas has complied with the requirements of
paragraph (b)(5) and (b)(6) for such fuel.
(8) No later than May 4, 1996, a small
refiner shall comply with the provisions specified in paragraphs
(b)(3) and (b)(6).
(4) Previously Exempt or Non-compliant Facilities
A person burning gaseous fuel containing sulfur compounds in excess of the limits specified in Table 1 and whose facility had been previously exempt from this rule pursuant to paragraph (g)(8) or who without the use of any sulfur removal or control system, has been in compliance with the limits specified in Table 1, shall:
(A) submit for approval by the Executive Officer within 30 days from the time of exceedance or non-compliance, a plan to demonstrate compliance with the requirements of the rule;
(B) submit to the Executive Officer an application for a fuel gas control system within six months of the time of exceedance of the exemption criteria specified in paragraph (g)(8), or non-compliance with the limit;
(C) Demonstrate compliance with the limit specified in Table 1 no later than eighteen (18) months after the time of exceedance, or by July 1, 1997, whichever is later; and
(D) Comply with paragraph (d)(3).
(d) Monitoring Requirements
(1) Prior to the final compliance date specified in Table 1, a person burning landfill gas or sewage digester gas in stationary equipment requiring a permit to operate by the District shall install and properly operate a continuous fuel gas monitoring system (CFGMS) to determine the sulfur content of the fuel gas prior to burning, or a continuous emission monitoring system (CEMS) to determine SOx emissions after burning. Such continuous monitor shall be approved according to the requirements set forth in Attachment A. An alternative method that ensures adequate compliance with the daily total sulfur content limitation of paragraphs (c)(1), (2) and (3) of this rule may be used upon written approval by the Executive Officers of the District, the California Air Resources Board (CARB), and the Regional Administrator of the Environmental Protection Agency (EPA), Region IX. At a minimum, the alternative method shall meet the specifications of Attachment A, Section III.
(2) A person burning gaseous fuels other than natural gas, landfill gas, or sewage digester gas in stationary equipment requiring a District permit to operate shall install and properly operate a CFGMS to determine the total sulfur content of the gaseous fuel prior to burning, or a CEMS to determine the sulfur oxides (SOx) emissions after burning according to the applicable requirements set forth in Attachment A.
A person shall not mix refinery gases with natural gas, propane or other fuels upstream of the monitoring device.
(3) A person subject to (c)(4) of this rule shall install and properly operate a CFGMS to determine the sulfur content in the fuel gas prior to combustion, or CEMS to determine the sulfur oxide emissions after burning, twelve months from the date a Permit to Construct a sulfur removal system is issued. Such monitor shall be approved according to the requirements of Attachment A, or an alternative method may be used upon approval by the Executive Officers of the District, California Air Resources Board (CARB), and the Regional Administrator of the Environmental Protection Agency, Region IX.
(4) A person installing a continuous monitor shall submit to the District for approval, a quality assurance procedure specified in EPA 40 CFR 60, Appendix F, Procedure 1.
(A) The quality assurance procedure specified above shall be approved in writing by the Executive Officer before the CFGMS (when applicable) or CEMS final certification.
(B) Any CFGMS or CEMS deemed to be out of control, as specified in Attachment A, according to the facility quality assurance procedure approved by the Executive Officer shall be corrected within 72 hours, as demonstrated by meeting the performance specification for which it was deemed out of control.
(i) The person operating the CFGMS or CEMS shall notify the Executive Officer by telephone or facsimile of any breakdown of the monitoring systems within 24 hours of such breakdown. Such report shall identify the time, location, equipment involved, and contact person.
(ii) The person shall keep a record of any breakdown of the monitors and shall maintain such record for at least two years, and make it available to the District staff upon request.
(iii) The person who complies with the provisions of clauses (d)(4)(B)(i) and (ii) shall not be considered in violation of this rule for the 72 hour period of breakdown.The person burning any gaseous fuel subject to paragraph (c)(2), (c)(3), or (c)(4) is exempt from the requirements of paragraphs (d)(1) through (d)(5) if such person demonstrates to the satisfaction of the Executive Officer that the supplier of the gaseous fuel or petroleum refinery gas has complied with the requirements of paragraphs (d)(1) through (d)(5) for such fuel.
(c e) Reporting and Recordkeeping Requirements
(1) Except at electric utility generating facilities and refineries,
A a person burning gaseous fuel other
than natural gas in permitted stationary equipment
requiring a District permit to operate, except
at electric power plants and refineries, shall submit
to the Executive Officer annual reports of the monthly fuel consumption,
and the monthly average sulfur
content, and the maximum 4-hour average total
sulfur content of the fuel consumed. Such report shall be submitted
30 days following the end of the reporting year, and shall consist
of the amount of any gaseous fuel consumed monthly, the
monthly average sulfur content as determined by the device
specified in paragraph (b)(5) (d)(1), (d)(2),
or (b)(6) (d)(3) of this rule, and
total SOx emissions.
(2) A person burning gaseous fuel other than natural gas
in stationary equipment located at electric power
plants utility generating facilities and
or refineries shall submit to the Executive Officer monthly
reports of the daily fuel consumption, the daily
monthly weighted average sulfur content (except for
natural gas), and the maximum 4-hour average sulfur content
of the fuel consumed, as determined by the device specified in
paragraph (b)(5) or (b)(6)
(d)(2) of this rule and the total SOx emissions. The
report shall be submitted within 30 days following the end of
the reporting month.
(3) The information specified in paragraphs (c)(1)
(e)(1) and (c)(2) (e)(2) shall
be maintained at the facility for at least two years, and be
made available to the District staff upon request.
(d) Exemptions
The provisions of this rule shall not apply to the following
cases where the person seeking the exemption shall supply the
proof of the applicable criteria to the satisfaction of the Executive
Officer:
(1) Gaseous fuels containing sulfur used
in the production of sulfur or sulfur compounds.
(2) Burning of waste gases provided that:
(A) The gross heating value of such gases
is less than 2670 kilogram calories per cubic meter (300 British
Thermal Units per cubic foot) at standard conditions; and
(B) Any supplemental fuel used to burn
such waste gases does not contain sulfur or sulfur compounds in
excess of the amount specified in this rule.
(3) Burning of gases from FCCU regenerators
subject to District Rule 1105.
(4) Gases vented during refinery turnaround
pursuant to District Rule 1123.
(5) Gases vented to a control system
pursuant to District Rules 466 and 1173.
(6) Gases vented intermittently to fuel
gas or waste gas disposal systems from pressure control valves,
sight glasses, compressor bottles, sampling systems, and pump
and compressor case vents.
(7) Any facility which emits less than
5 pounds per day total sulfur compounds from gaseous fuels except
natural gas, calculated as hydrogen sulfide. Emissions of total
sulfur compounds shall be measured based on fuel analysis, using
the test method specified in paragraph (e)(1), and the maximum
daily gaseous fuel consumption.
(e f) Test Methods
The following test methods shall may be
used by the Executive Officer to verify compliance with
the provisions of this rule:
(1) For determination of compliance with sulfur content requirements of subdivision (c):
(1)(A) The reference method for determining
the concentration of sulfur compounds in a gaseous fuel, calculated
as hydrogen sulfide, shall be SCAQMD District
Method 307-91 - Determination of Sulfur in a Gaseous Matrix, or
any other method demonstrated by the applicant to be equivalent
and approved in writing by the Executive Officers of the
District, the CARB, and the Regional Administrator of the
EPA, Region IX, or
(B) Data obtained from a continuous monitor, which is installed and properly operated according to subdivision (d) and as approved by the Executive Officer pursuant to the guidelines specified in Attachment A.
(2) The gross heating value of gaseous fuels shall be determined
by ASTM Method D 3588-91 or, if applicable ASTM Method
D 4891-89 where applicable.
(3) The methane content of gaseous fuels shall be determined by ASTM Method D 1945-81.
(g) Exemptions
Unless otherwise specified, all of the provisions of this rule shall not apply to the following cases provided, that the person seeking the exemption supplies proof of applicable criteria to the satisfaction of the Executive Officer:
(1) A person selling, for use in the jurisdiction of the District, any gaseous fuel not complying with paragraphs (c)(1) through (c)(3) provided that:
(A) The gaseous fuel is delivered directly to a sulfur removal unit which reduces the sulfur content to the limits specified in paragraphs (c)(1) through (c)(3); and
(B) The seller notifies the Executive Officer prior to any such sale of the quantity, heating value, and composition of the gaseous fuel to be sold; and
(C) The buyer has an approved Permit to Construct and/or Operate for the sulfur removal unit that will be used to treat the purchased gas.
(2) Gaseous fuels containing sulfur used in the production of sulfur or sulfur compounds.
(3) Waste gases being burned provided that:
(A) The gross heating value of such gases is less than 2670 kilogram calories per cubic meter (300 British Thermal Units per cubic foot) at standard conditions; and
(B) Any supplemental fuel used to burn such waste gases does not contain sulfur or sulfur compounds in excess of the amount specified in this rule.
(4) Gases being burned from fluidized catalytic cracking unit (FCCU) regenerators subject to District Rule 1105 or Regulation XX.
(5) Gases vented during refinery turnaround pursuant to District Rule 1123 or Regulation XX.
(6) Gases vented to a control system pursuant to District Rule 466 and 1173 or Regulation XX.
(7) Gases vented intermittently to fuel gas or waste disposal system from pressure control valves, sight glasses, compressor bottles, sampling systems, and pump and compressor case vents.
(8) Any facility which emits less than 5 pounds per day total sulfur compounds, calculated as hydrogen sulfide, from the burning of gaseous fuels other than natural gas. Emissions of total sulfur compounds shall be measured based on fuel analysis, using the test method specified in paragraph (f)(1), and the maximum daily gaseous fuel consumption.
(9) A person is exempt from the requirements of paragraph (d)(1) and (d)(2) if the person demonstrates to the satisfaction of the Executive Officer that the supplier of the gaseous fuel has complied with the requirements of subdivision (d) for such fuel.
(10) Any gaseous fuel sold or purchased by a RECLAIM SOx facility is exempt from the sulfur content requirements specified in paragraphs (c)(1), (2) and (3), provided that:
(A) both the buyer and seller of the gaseous fuel submit to the Executive Officer monthly written report of the quantities and daily averages of the total sulfur contents of the gaseous fuel sold to the buyer or purchased from the seller. The daily average of total sulfur contents of gaseous fuels shall be monitored and reported to the District in a manner and format specified by the Executive Officer. Such report shall be submitted within 30 calendar days following the end of the reporting month; and
(B) the RECLAIM SOx facility reports to the District and includes all SOx emissions generated from the burning of such gaseous fuel, as part of the facility's total SOx emissions pursuant to Rule 2004.
ATTACHMENT A
SECTION I
REQUIREMENTS FOR
CONTINUOUS FUEL GAS MONITORING SYSTEM (CFGMS)
A continuous fuel gas monitor used for determining the sulfur content of any gaseous fuel shall:
(1) Continuously monitor and record the concentration by volume (dry basis) of sulfur compounds in the gaseous fuel.
(2) Have the span value of the monitor set so that all readings fall between 20 and 95 percent of scale.
(3) Check for calibration drift of the monitoring system at least once daily (approximately 24-hr interval) at two concentrations, one high level and one low level. Whenever the daily high level or low level calibration drift exceeds 5% of analyzer full scale span, the monitoring system shall be deemed to be out of control and subject to the requirements of subparagraph (d)(4)(B) of this rule.
(4) Determine the relative accuracy of the monitor which shall be no greater than 20 percent of the mean value of the reference method test data.
(5) Be able to record negative values of zero drift.
(6) Report the concentration of the sulfur compounds calculated as hydrogen sulfide.
SECTION II
REQUIREMENTS FOR
CONTINUOUS EMISSIONS MONITORING SYSTEMS (CEMS)
A stack CEMS used for monitoring the sulfur dioxide emissions from the burning of any gaseous fuel shall:
(1) Continuously monitor and record the concentration by volume (dry basis, zero percent excess air) of sulfur compounds into the atmosphere;
(2) Include an oxygen monitor for correcting the data for excess air;
(3) Have span ranges of 20 ppm sulfur and 10 percent oxygen;
(4) Be able to measure a sulfur compound concentration emission
limit of 5 ppm (dry basis, zero percent excess air), which is
stoichiometrically equivalent to the limit of sulfur compound
content of 40 ppm calculated as hydrogen sulfide in the gaseous
fuels; and
(5) Use District Methods 307-91 or 6.1 (as applicable
for sulfur compound analysis) and District Method 3.1 (for oxygen
content analysis), or any other methods demonstrated by the applicant
to be equivalent and approved in writing by the Executive Officers
of the District, and the CARB,
and the Regional Administrator of the EPA, Region IX, for conducting
the relative accuracy evaluations. The relative accuracy limit
shall be 1 ppm and zero drift (2-hour and 24-hour) and calibration
drift (2-hour and 24-hour) limits for sulfur compounds monitor
shall be 5 percent of the span range.; and
(6) Check for calibration drift of the monitoring system at least once daily (approximately 24-hr interval) at two concentrations, one high level and one low level. Whenever the daily high level or low level calibration drift exceeds 5% of analyzer full scale span, the monitoring system shall be deemed to be out of control and subject to the requirements of subparagraph (d)(4)(B) of this rule.
(7) Facilities burning fuel gas subject to this rule shall comply with the requirements of Rule 218 except where specific requirements have been incorporated into this rule.
SECTION III
GUIDELINES FOR APPROVAL OF
ALTERNATIVE MONITORING PLAN
BY THE EXECUTIVE OFFICER
An alternative monitoring plan shall be submitted to the Executive Officer for approval in lieu of a continuous fuel gas monitoring system (CFGMS) or a continuous emission monitoring system (CEMS), which contains:
(1) A test program to determine the relationship of hydrogen sulfide and total sulfur in the fuel gas using District Method 307-91. When a correlation is established, a colorimetric test, or other alternative method approved by the Executive Officer as being equivalent or better in establishing such correlation, may be conducted regularly to determine total sulfur using hydrogen sulfide as a surrogate.
(2) An error analysis between colorimetric, or other approved alternative method readings and the total reduced sulfur analysis obtained from District Method 307-91. To demonstrate equivalency, a correlation between the two methods of analyses shall not exceed + 4 ppm.
(3) A schedule for a daily or more frequent analysis of the fuel gas for hydrogen sulfide (H2S) using the colorimetric test, or other approved alternative method, and a minimum weekly analysis of the fuel gas using District Method 307-91. A different frequency of analysis may be used if the Executive Officer determines that such frequency is adequate to ensure compliance with the daily total sulfur limits of this rule.
(4) When the sulfur level is suspected to be
at or above the 40 ppm level as determined by the colorimetric
or other alternative method, a procedure to obtain at minimum
a daily sample to be tested according to District Method 307-91
until three consecutive daily samples show that total sulfur is
below the 40 ppm limit.
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
Draft Supplemental Environmental Assessment for:
Proposed Amended Rule 431.1 - Sulfur Content of Gaseous Fuels
July 1995
Deputy Executive Officer
Barry R. Wallerstein, D.Env.
Director of Planning
Jack P. Broadbent
Planning Manager
Cindy S. Greenwald, J.D.
AUTHOR: TARA SHEEHY - TECHNICAL WRITER
REVIEWED BY: ROBERT N. KWONG - SENIOR DEPUTY DISTRICT COUNSEL
MOHSEN NAZEMI - SENIOR MANAGER
JONATHAN NADLER - AIR QUALITY SPECIALIST
LINDA BASILIO - AIR QUALITY ENGINEER
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
GOVERNING BOARD
Chairman: JON D. MIKELS
San Bernardino County Representative
Vice Chairman: WILLIAM A. BURKE, Ed.D.
Speaker of the Assembly Appointee
MEMBERS:
MICHAEL D. ANTONOVICH
Los Angeles County Representative
MARVIN BRAUDE
Cities Representative, Los Angeles County, Western Region
CANDACE HAGGARD
Cities Representative, Orange County
HUGH HEWITT, Esq.
Governor's Appointee
MEE HAE LEE
Senate Rules Committee Appointee
RONALD O. LOVERIDGE
Cities Representative, Riverside County
LEONARD PAULITZ
Cities Representative, San Bernardino County
JAMES SILVA
Orange County Representative
NELL SOTO
Cities Representative, Los Angeles County, Eastern Region
S. ROY WILSON, Ed.D.
Riverside County Representative
EXECUTIVE OFFICER
JAMES M. LENTS, Ph.D.
TABLE OF CONTENTS
Executive Summary 1-1
Legislative Authority 1-2
Existing Setting 2-1
Appendix A - Environmental Checklist Form
Appendix B - Proposed Rule 431.1 - Sulfur Content of Gaseous Fuels
Executive Summary
Legislative Authority
Preparation of a Supplemental Environmental Assessment
CEQA Documentation for Rule 431.1
Project Description
Control Method
Emission Impact
Conclusion
EXECUTIVE SUMMARY
Pursuant to the California Environmental Quality Act (CEQA) (California Public Resources Code Section 21000 et seq.), this document analyzes the potential environmental impacts of the proposed amendments to Rule 431.1 - Sulfur Content of Gaseous Fuels. This environmental assessment (EA) is a supplement to the Final Environmental Assessment for Rule 431.1, which was certified by the South Coast Air Quality Management District's (SCAQMD) Governing Board on May 4, 1990.
The proposed amendments to Rule 431.1 seek to extend the date for compliance with the sulfur limit of 40 parts per million (ppm) for landfill facilities to July 1, 1997 from the prior date of May 4, 1994. The amendments would allow landfill operations to emit a daily average sulfur limit of 150 ppm. The extension of the final compliance date for landfills is intended to allow for the continuation of ongoing research into the development of sulfur removal technology. The amendments provide for an interim compliance limit for small refiners of 800 ppm sulfur until the final compliance with the 40 ppm limit in May 1996. The amendments would allow landfills and sewage treatment facilities to meet the 40 ppm final compliance limit for sulfur content as a daily average rather than as a four hour average as currently required. The amendments also propose to provide a monthly averaging option for digester and landfill gases, for those facilities which install continuous total sulfur emission monitors. A maximum instantaneous limit of 500 ppm for digesters and 200 ppm for landfills who choose monthly averaging is also proposed. Use of an Optional Facility Compliance Plan (OFCP) is also being proposed. The OFCP would, among other things, allow a facility with more than one emission source to bubble the sulfur emissions from the facility as a whole.
Additional amendments to Rule 431.1 would allow for the sale of refinery gas between a facility subject to the Regional Clean Air Incentives Market (RECLAIM) program and a non-RECLAIM facility subject to Rule 431.1 and other command-and-control regulations. The amendments allow for the sale of fuel gas in excess of the 40 ppm sulfur limit as long as the RECLAIM facility reports all oxides of sulfur (SOx) emissions generated from the burning of such gaseous fuel, as part of the overall SOx emissions for the RECLAIM SOx facility. Changes and definition additions were also incorporated into the proposed amendments along with additional reporting and monitoring requirements.
Air quality is the only area identified as having potentially significant adverse environmental impacts as a result of the proposed amendments. The proposed amendments have the potential to result in increased emissions from digesters at sewage treatment plants as well as a loss of future emission reductions due to delay of the final compliance date for landfills. The air quality impacts are significant, therefore, a Statement of Findings and a Statement of Overriding Considerations will be prepared and included in the final Board package for the Governing Board's consideration.
LEGISLATIVE AUTHORITY
Rule Development
The California Legislature created the SCAQMD in 1977 as the agency responsible for developing and enforcing air pollution control rules and regulations in the South Coast Air Basin (Basin). By statute, the SCAQMD is required to adopt an air quality management plan (AQMP) demonstrating compliance with all state and federal ambient air quality standards for the District.2 Furthermore, the SCAQMD must adopt rules and regulations that carry out the AQMP.3 Rule 431.1 - Sulfur Content of Gaseous Fuels, was originally adopted and is currently being amended, pursuant to these mandates.
Environmental Impact Analysis
The proposed amendments to Rule 431.1 - Sulfur Content of Gaseous Fuels, are a "project" as defined by CEQA. SCAQMD is the lead agency for the project and has prepared the appropriate environmental analysis pursuant to its certified regulatory program (California Public Resources Code Section 21080.5). California Public Resources Code Section 21080.5 allows public agencies with regulatory programs to prepare a plan or other written document in lieu of an environmental impact report once the Secretary of the Resources Agency has certified the regulatory program. SCAQMD's regulatory program, Rule 110, was certified by the Secretary of the Resources Agency on March 1, 1989. Pursuant to Rule 110, SCAQMD has prepared this Supplemental Environmental Assessment (EA).
CEQA requires that the potential environmental impacts of proposed projects be evaluated and that feasible methods to reduce or avoid adverse environmental impacts be identified. To fulfill the purpose and intent of CEQA, the SCAQMD has prepared this Supplemental EA to address the potential environmental impacts associated with the proposed amendments to Rule 431.1. Prior to making a decision on the proposed amendments, the SCAQMD Governing Board must review and certify the Supplemental EA as providing adequate information on the potential adverse environmental impacts of the proposed amendments to the rule.
PREPARATION OF A SUPPLEMENTAL ENVIRONMENTAL ASSESSMENT
State CEQA Guidelines (Title 14, California Code of Regulations, Section 15000 et seq.), require additional analysis to a previously prepared and certified CEQA document if subsequent changes are proposed to the project which involve potential environmental impacts not previously considered (CEQA Guidelines Sections 15153 and 15162). Where only minor additions or changes would be necessary to make the previous environmental analysis adequately apply to the project in the changed situation, a supplement to the previous document may be prepared (CEQA Guidelines Section 15163). A supplemental CEQA document need only contain the information necessary to make the previous document adequate for the project as revised, and may be circulated by itself without recirculating the previous draft or final CEQA document (CEQA Guidelines Section 15163).
The SCAQMD has evaluated the proposed amendments to Rule 431.1 to determine if they raise new information of substantial importance relative to the Final EA prepared for Rule 431.1 - Sulfur Content of Gaseous Fuels in May 1990. Since only minor changes are required in the previous EA to account for the proposed amendments, a supplement is the appropriate document. This Supplemental EA focuses solely on the currently proposed amendments to Rule 431.1, and not on the entire rule itself as was done in the May 1990 EA prepared for Rule 431.1. Any environmental topics that were addressed in the previously prepared and certified Final EA for Rule 431.1 that are not affected by the proposed amendments will not be included in this Supplemental EA.
CEQA DOCUMENTATION FOR RULE 431.1
SCAQMD rules, as ongoing regulatory programs, have the potential to be revised over time due to a variety of factors. Environmental analyses of subsequent amendments to SCAQMD rules or regulations are performed to supplement the original analysis. Consequently, as discussed below, several CEQA documents have been prepared to analyze Rule 431.1 - Sulfur Content of Gaseous Fuels and its various amendments over the years.
This document constitutes a supplement to the May 1990 Final Environmental Assessment for Rule 431.1 - Sulfur Content of Gaseous Fuels. In addition, several other documents were prepared subsequent to the May 1990 amendments. These documents can all be obtained by contacting SCAQMD's Public Information Center at (909) 396-3600.
Notice of Preparation and Initial Study - A Notice of Preparation was prepared for the proposed amendments to Rule 431.1. The NOP was circulated for public review and comment from February 27, 1990, to March 23, 1990.
Final Environmental Assessment - Sulfur Content of Gaseous Fuels (5/90): This document analyzed the incorporation of Control Measure 88-F-2 from the 1989 Air Quality Management Plan into Rule 431.1. The environmental impact areas examined in the EA included the following: air quality, water quality, natural resources, risk of upset, solid waste, and energy. The EA found no significant impacts to remain after mitigation.
Final Subsequent Environmental Assessment (10/92): The October 1992 amendments extended the date for final compliance with a 40 ppm sulfur limit for landfill gases to May 4, 1994. In addition, the compliance date for small refiners was extended to May 4, 1996. The Subsequent EA identified air quality as being significantly impacted by the proposed amendments since the compliance delay would result in a delay of previously anticipated emission reductions.
PROJECT DESCRIPTION
Background
Rule 431.1 was originally adopted on November 4, 1977, to control oxides of sulfur (SOx) emissions from gaseous fuels being bought, sold or burned in the south coast air district. Until January 1982, Rule 431.1 had set limits for sulfur compounds in gas sold at 80 parts per million (ppm) and for gas burned on-site at 800 ppm. At the January 1982 public hearing, the SCAQMD Governing Board instructed staff to investigate whether or not a single limit would be applicable to all fuel gases either sold or burned on site. The investigation found that refineries experience occasional peaks in their sulfur content, which could approach the 800 ppm level. Therefore, refineries would be in violation if a lower sulfur limit was imposed.
This investigation led to the May 1983 amendment which maintained three different emission limits: 250 ppm for landfill and sewage digester gases for sale; 80 ppm for other gaseous fuel for sale; and 800 ppm for all gaseous fuel for on-site burning. The rule was revisited in 1990 to review the sulfur removal technology and associated costs to implement Control Measure 88-F-2 of the 1989 AQMP. The measure recommended a uniform sulfur content limit of 100 ppm for both off-site sales and on-site burning. The 1990 amendment reduced the sulfur limit in gaseous fuels to 40 ppm by volume whether sold off-site or burned on-site with a final compliance date of May 4, 1992. The amendment also required a continuous total sulfur fuel monitor to be installed by May 4, 1992. A total sulfur monitor was not available in the market at that time and research showed that it may not be available by the May 4, 1992, deadline. The rule was again amended in April 1992 to extend the continuous monitor requirement for one year. Subsequent amendments were adopted to accommodate the yet-to-be developed control technology and continuous monitoring system.
Proposed Amendments
Rule 431.1 presently sets the sulfur content limit for landfill gas at 40 ppm averaged over a consecutive 4-hour period effective May 4, 1994. Staff is now proposing to allow landfills a compliance limit of 150 ppm averaged daily. If approved the limit would become effective the day that the amendments are adopted by the SCAQMD's Governing Board. While the majority of landfills currently comply with the 40 ppm limit a few landfill facilities within the District are under a variance from the sulfur content limit requirements of Rule 431.1 until the end of 1995. At this time there are no known overt actions which are or can be taken by landfills to directly enable them to comply with the existing sulfur limits. Those landfills which do comply with the 40 ppm limit do so because of the nature of the gas produced and perhaps some particular qualities of the site itself. Members of the landfill industry, in cooperation with the sanitation districts under variance, are conducting a study as part of their variance requirements, to determine the technologies needed to reduce the sulfur content in landfill gas. The final sulfur compliance limit of 40 ppm is being proposed for delay until July 1, 1997. The final 40 ppm compliance limit for landfills is proposed as a daily limit. If a facility installs a continuous emission monitor to measure total sulfur emissions, it could choose to comply with the 40 ppm limit as a monthly average with a maximum instantaneous limit of 200 ppm.
The amendments propose to allow sewage digesters to comply with the 40 ppm limit (effective upon adoption) either through a daily or monthly average. Just as with the landfills in order to qualify for monthly averaging the facility must install a continuous total sulfur monitor. Under the proposed amendments sewage treatment facilities choosing a monthly averaging program will be limited to a 500 ppm instantaneous emission level.
The use of an Optional Facility Compliance Plan (OFCP) is also being proposed. The OFCP would, among other things, allow a facility with more than one emission source to bubble the sulfur emissions from the facility as a whole.
The amendments also include a provision whereby RECLAIM facilities who are not subject to the provisions of Rule 431.1 could sell non-compliant fuel gas to non-RECLAIM facilities (who are subject to the requirements of Rule 431.1). Such transactions would be allowed if the RECLAIM facility incorporates any SOx emissions in excess of 40 ppm into their RECLAIM facility allocation. The provision would allow business transactions to continue for at least one refinery in the South Coast Air Basin and its gas purchasing customer.
The proposed amendments also incorporate language clarifications, definitions, and an extension of the 800 ppm compliance limit for small refiners.
CONTROL METHODS
The main focus of the proposed amendments is the replacement of the current 40 ppm sulfur limit for landfill gas with a 150 ppm limit until July 1, 1997 and the change of the averaging period available to both landfills and sewage digesters. The first will allow the continued study of the control technologies which have not been fully developed for landfill gas. As a condition of their variances the sanitation districts, in cooperation with the members of the landfill industry, have investigated the available sulfur control technologies worldwide to determine potential technologies to reduce sulfur content in landfill gas. The study focused on cost-effectiveness, commercial availability and applicability, process selectivity for hydrogen sulfide (H2S) versus carbon dioxide (CO2), waste generation, the potential transfer of technology to landfill and sewage digester gases, and the sources of sulfur in the landfill environment. The study identified seventy-eight sulfur removal processes, out of which fourteen are being considered for further investigation.
EMISSION IMPACT
The proposed amendments will result in a delay of emission reductions as well as potential emission increases. There have already been emission reductions foregone between May 4, 1994 and the present as a result of landfill facilities currently not complying with the 40 ppm limit. An estimate of the emissions reductions foregone between May 1994, and the present can be calculated by subtracting the average sulfur content recorded from those landfills not in compliance and subtracting that figure from what would have been produced at a 40 ppm level and multiplying the number by the volume of gas produced. Using that formula the sulfur emission reductions foregone were estimated at approximately 500 pounds (0.25 ton) per day. Those same excess emissions are expected to continue until the proposed new final compliance date of July 1, 1997.
For the purpose of the CEQA analysis a worst case assumption was, nevertheless, made assuming that all facilities would rise to the proposed 150 ppm limit until final compliance in 1997. Under such a worst case assumption emissions in excess of the 40 ppm limit could be as high as 1.39 tons per day. As previously stated landfills cannot currently take any specific action to reduce the sulfur emissions from their sites. Conversely neither can they take action or cease taking action which would cause the sulfur content of the landfill gas to increase. The emission reductions foregone due to the proposed delay of the 40 ppm compliance limit are, therefore, expected to remain at approximately 500 pounds (0.25 ton) per day until final compliance with the 40 ppm limit on July 1, 1997.
Additional emission increases may be expected to occur under the proposed amendments as a result of the monthly averaging period that would be made available to sewage treatment facilities. At present only three sewage treatment facilities run by the City of Los Angeles, the County of Los Angeles and the County of Orange could benefit from and are, therefore, likely to choose the monthly averaging option. The amendments propose to allow a maximum instantaneous peak emission limit of 500 ppm. A 500 ppm exceedance for each facility on the same day was assumed to be the worst case operating conditions. The daily volume of gas produced by each facility was determined from SCAQMD records. The daily volume was then multiplied by the excess sulfur content (500 ppm - 40 ppm) and a pound per day excess for each facility was determined. The total worst case single day increase in SOx emissions from sewage treatment facilities was estimated to be 1.6 tons (3200 pounds) per day.
The combined total worst case emission increase could, therefore, be as high as 2.99 tons per day. A more likely scenario would be to see much lower excess emissions on any given day. As noted above landfill operations are expected to remain at approximately 500 pounds per day and the three sewage treatment facilities could only reach a 500 ppm peak on two days out of the month before exceeding the monthly average limit.
Potential localized air pollution impacts could occur from the transfer and sale of non-compliant fuel gas to other facilities in the south coast air district. Increased SOx emissions have the potential to create a localized odor nuisance. SOx emissions also contribute to the creation of PM10 and sulfate emissions. The potential SOx impacts would not be an emission increase, but rather, a shift in emissions from one area in the District to another.
CONCLUSION
The amendments to Rule 431.1 are being proposed in order to allow the sanitation districts time to determine the most feasible, cost-effective, control approach to reduce landfill gas emissions. Extensive research projects have already been undertaken to examine this industry and several possible control methods are being evaluated. The extension in the compliance period will allow the best approach to be selected. The amendments may result in an emission increase, and certainly will result in a delay in emission reductions.
The amendments are also being proposed in order to clarify that SOx RECLAIM facilities may sell non-compliant fuel gas to non-RECLAIM facilities as long as the excess emissions are accounted for in the RECLAIM facilities' Allocation. This will allow business transactions to continue between at least one refinery and its buyer of excess gas.
Existing Setting
Potential Environmental Impacts
Environmental Impacts Found Not To Be Significant
EXISTING SETTING
The SCAQMD has jurisdiction over approximately 12,000 square miles consisting of the four-county South Coast Air Basin and the Los Angeles County and Riverside County portions of the Southeast Desert Air Basin (SEDAB). This combined area is hereafter referred to as the District. The Basin is bounded by the Pacific Ocean to the west and the San Gabriel, San Bernardino, and San Jacinto mountains to the north and east. It includes all of Orange County and the nondesert portions of Los Angeles, Riverside, and San Bernardino counties. The Los Angeles County portion of the SEDAB (known as North county or Antelope Valley) is bounded by the San Gabriel Mountains to the south and west, the Los Angeles/Kern county border to the north, and the Los Angeles/San Bernardino county border to the east. The Riverside County portion of the SEDAB is bounded by the San Jacinto Mountains in the west and spans eastward up to the Palo Verde Valley. The federal nonattainment area (known as the Coachella-San Jacinto Planning Area) is a subregion of the Riverside County and SEDAB that is bounded by the San Jacinto Mountains to the west and the eastern boundary of the Coachella Valley to the east (Figure 2-1). The following discussion of current air quality presents information for the entire District.
Figure 2-1
South Coast Air Quality Management District
The existing air quality setting for the District is presented below. The setting is based on 1993 air quality data. For a complete discussion of current and projected future air quality in the District, with and without additional control measures, please refer to the Final 1994 AQMP, including its Appendices and the 1994 AQMP Final EIR. In addition, the Final 1994 AQMP EIR contains information on the existing setting for other environmental areas (e.g., water resources, energy, land use, etc.). Copies of the above-referenced documents are available from the SCAQMD's Public Information Center by calling (909) 396-3600.
Air Quality
EXISTING SETTING: Air quality in the District has shown substantial improvement over the last two decades. Nevertheless, some federal and state air quality standards are still exceeded frequently and by a wide margin. Ozone, CO, and PM10 continue to be the area's most severe air pollution problems. The following paragraphs briefly summarize the status of the District's air quality in terms of the criteria pollutants identified in Tables 2-1 and 2-2.
The District exceeds the federal ozone standard far more frequently than any other area in the United States. Ozone levels exceeded the federal standard by the widest margin compared to other criteria pollutants, with a maximum concentration that was 250 percent of the standard. Ozone concentrations exceeded the state standard at all monitored locations.
Unlike primary criteria pollutants that are emitted directly from an emission source, ozone is a secondary pollutant. It is formed in the atmosphere through a photochemical reaction of VOC, NOx, oxygen, and other hydrocarbon materials with sunlight. Ozone is a deep lung irritant, causing the passages to become inflamed and swollen. Exposure to ozone produces alterations in respiration, the most characteristic of which is shallow, rapid breathing and a decrease in pulmonary performance. Ozone reduces the respiratory system's ability to fight infection and to remove foreign particles. People who suffer from respiratory diseases such as asthma, emphysema, and chronic bronchitis are more sensitive to ozone's effects. In severe cases, ozone is capable of causing death from pulmonary edema. Early studies suggested that long-term exposure to ozone results in adverse effects on morphology and function of the lung and acceleration of lung-tumor formation and aging. Ozone exposure also increases the sensitivity of the lung to bronchoconstrictive agents such as histamine, acetylcholine, and allergens.
The CO standard was monitored at 20 locations in the District in 1994. The federal and state 8-hour CO standards were exceeded at four locations. Source/Receptor Area No. 12, South Central Los Angeles County, reported by far the greatest number of exceedances of the federal and state standards (22 and 26 days, respectively).
CO is a colorless, odorless gas formed by the incomplete combustion of fuels. CO competes with oxygen, often replacing it in the blood, thus reducing the blood's ability to transport oxygen to vital organs in the body. The ambient air quality standard for carbon monoxide is intended to protect persons whose medical condition already compromises their circulatory system's ability to deliver oxygen. These medical conditions include certain heart ailments, chronic lung diseases, and anemia. Persons with these conditions have reduced exercise capacity even when exposed to relatively low levels of CO. Fetuses are at risk because their blood has an even greater affinity to bind with CO. Smokers are also at risk from ambient CO levels because smoking increases the background level of CO in the blood.
Concentrations of nitrogen dioxide (NO2) declined over the period 1976 to 1994. By 1991, exceedances of the federal standard were limited to one location in Los Angeles County. Los Angeles is the only county in the United States classified as nonattainment for the federal NO2 standard. For the first time in 1992, and again in 1993 and 1994, no District location exceeded the federal standard. 1994 was the first year that the state NO2 standard was not exceeded.
NO2 is a brownish gas that is formed in the atmosphere through a rapid reaction of the colorless gas nitric oxide (NO) with atmospheric oxygen. NO and NO2 are collectively referred to as NOx. NO2 can cause health effects in sensitive population groups such as children and people with chronic lung diseases. It can cause respiratory irritation and constriction of the airways, making breathing more difficult. Asthmatics are especially sensitive to these effects. People with asthma and chronic bronchitis may also experience headaches, wheezing and chest tightness at high ambient levels of NO2. Nitrogen dioxide is suspected to reduce resistance to infection, especially in young children.
In 1994, PM10 was monitored at 19 locations in the District. The federal annual standard was exceeded at four locations and the federal 24-hour standard was exceeded at one location. The state annual standard was exceeded at 15 locations and the state 24-hour standard was exceeded at 18 locations.
PM10 is defined as suspended particulate matter 10 micrometers or less in diameter and includes a complex mixture of man-made and natural substances including sulfates, nitrates, metals, elemental carbon, sea salt, soil, organics and other materials. PM10 may have adverse health impacts because these microscopic particles are able to penetrate deeply into the respiratory system. In some cases, the particulates themselves may cause actual damage to the alveoli of the lungs or they may contain adsorbed substances that are injurious. Children can experience a decline in lung function and an increase in respiratory symptoms from PM10 exposure. People with influenza, chronic respiratory disease and cardiovascular disease can be at risk of aggravated illness from exposure to fine particles. Also, increases in death rates have been statistically linked to corresponding increases in PM10 levels.
Though sulfur dioxide (SO2) concentrations in the District have been reduced to levels well below state and federal standards, further reductions in emissions of SOx are needed to comply with standards for other pollutants (sulfate and PM10).
SO2 is a colorless, pungent gas formed primarily by the combustion of sulfur-containing fossil fuels. Health effects include acute respiratory symptoms and difficulty in breathing for children.
Sulfates are a group of chemical compounds containing the sulfate group, which is a sulfur atom with four oxygen atoms attached. Though not exceeded in 1993, the state sulfate standard was exceeded at three locations in 1994.
Lead concentrations once exceeded the state and federal standards by a wide margin, but have not exceeded state or federal standards at any regular monitoring station since 1982. Special monitoring sites immediately downwind of lead sources have recorded very localized violations of the state standard in 1994.
It should be noted that there are no state or federal ambient air quality standards for VOCs because they are not classified as criteria pollutants. VOCs are regulated, however, because in the presence of sunlight they undergo photochemical reactions with NO2 molecules to form photochemical oxidants, most notably ozone. They are also transformed into organic aerosols in the atmosphere, contributing to higher PM10 levels and lower visibility.
Although health-based standards have not been established for VOCs, health effects can occur from exposures to high concentrations of VOC because of interference with oxygen uptake. In general, ambient VOC concentrations in the atmosphere are suspected to cause coughing, sneezing, headaches, nervousness, weakness, laryngitis, and bronchitis, even at low concentrations. Some hydrocarbon components classified as VOC emissions are thought or known to be hazardous. Benzene, for example, one hydrocarbon component of VOC emissions, is known to be a human carcinogen.
Table 2-1
State and Federal Ambient Air Quality Standards
Table 2-2
1994 Air Quality
Table 2-2 cont.
1994 Air Quality
POTENTIAL ENVIRONMENTAL IMPACTS
CEQA Requirements
CEQA Guidelines require environmental documents to identify and focus on the significant adverse environmental effects that may result from a proposed project (CEQA Guidelines Section 15126(a)). If significant adverse environmental impacts are identified, CEQA requires a discussion of measures that could either avoid or reduce those impacts to the greatest extent feasible (CEQA Guidelines Section 15126(c)).
The CEQA Guidelines recognize that the degree of specificity required in a CEQA document will depend on the type of project being proposed (CEQA Guidelines Section 15146). It is recognized that the detail of the environmental analysis for certain types of projects cannot be as great as for other types of projects. CEQA also recognizes that the identification of potential environmental impacts for proposed projects requires a degree of forecasting. CEQA Guidelines, Section 15144, states "while foreseeing the unforeseeable is not possible, an agency must use its best efforts to find out and disclose all that it reasonably can."
Environmental topics in a CEQA document that are evaluated for adverse impacts from a proposed project are established by the California Environmental Quality Act, Public Resources Code, Section 21000 et seq., and the state CEQA Guidelines as promulgated by the Secretary for Resources. The CEQA Guidelines recommend an analysis of impacts from a project for approximately 15 environmental categories. Projects are evaluated against these environmental impact categories in an Initial Study. Those environmental categories that could be adversely affected by the proposed project, based upon a preliminary analysis in the Initial Study (Environmental Checklist), are carried forward for analysis in the draft and final environmental document.
An environmental checklist for the proposed amendments can be found in Appendix A to this document. Of the 15 potential environmental impact categories, only air quality was initially determined to be potentially affected by the implementation of the proposed amendments. The following sections discuss how air quality may be affected by the proposed amendments.
Significance Criteria for Air Quality
The project will be considered to have a significant impact on the environment if emissions associated with the proposed amendments:
o Are greater than the daily emission significance thresholds established by the SCAQMD in the CEQA Air Quality Handbook (SCAQMD 1993).
o Violate any ambient air quality standard, contribute substantially to an existing or projected air quality violation, or expose sensitive receptors to substantial pollutant concentrations. (State CEQA Guidelines, 1994, page 139).
Air Quality Impacts
PROJECT-SPECIFIC IMPACT: The proposed amendments to Rule 431.1 would not implement the compliance deadline for the 40 ppm sulfur limit for landfills until July 1, 1997. SOx emission reductions previously anticipated from the existing rule would be foregone for a period of time. The proposed amendments may also result in an increase in SOx emissions beyond current levels. The following sections detail the SOx emission reductions foregone and potential increases as a result of the proposed amendments.
The maximum potential emission reductions foregone as a result of allowing landfill operations to operate at a 150 ppm sulfur limit until July 1, 1997 rather than the current limit of 40 ppm would be approximately 1.39 tons per day. Several landfills have been under variance during the past year. Based upon historical information obtained during the past year, actual excess emissions of hydrogen sulfide (H2S) from those facilities were approximately 500 pounds (0.25 ton) per day. Actual excess emissions may be slightly higher due to the presence of other sulfur compounds not measured. The 500 pounds per day figure was obtained by examining the fuel production at the respective facilities and calculating the H2S emissions in excess of 40 ppm with the corresponding volumes of gas produced. In that landfill operations have yet to develop a procedure by which they can reduce or increase the amount of sulfur in the gas produced it is not expected that those facilities currently operating below 150 ppm would rise to such a level. It is, therefore, expected that emission reductions foregone would remain at approximately 500 pounds (0.25 ton) per day until the 40 ppm limit takes effect in July 1997. SOx emissions of 500 pounds (0.25 ton) per day are considered significant under the SCAQMD's significance criteria of 150 pounds per day of SOx.
Sulfur emissions increases of 1.6 tons (3200 pounds) per day may occur under the proposed amendments as a result of allowing sewage treatment facilities to average their sulfur content over a monthly period with a 500 ppm instantaneous peak. At present three sewage treatment facilities (City of Los Angeles, the County of Los Angeles and the County of Orange) are likely to choose the monthly averaging option. A 500 ppm exceedance for each facility was used as the worst case operating conditions for any single day. The daily volume of gas produced by each facility was determined from SCAQMD records. The daily volume was then multiplied by the excess sulfur content (500 ppm - 40 ppm) and a pounds per day excess was determined. A maximum potential single day increase in SOx emissions of 1.6 tons per day was determined. Given the 40 ppm monthly average, a facility could only hit the 500 ppm peak on two days during any given month before causing the operation to exceed the monthly limit.
Under an absolute worst case scenario the maximum excess emissions on a given day could reach as high as 2.99 tons. A more realistic but still very conservative excess emission estimate is 1.85 tons per day of sulfur dioxide (0.25 + 1.6) as a result of adoption of the proposed amendments. A quarter of a ton of those sulfur emissions are expected to be temporary in nature and will cease once the final compliance limit of 40 ppm sulfur is applied to landfill operations in July 1997. The remaining 1.6 tons are intermittent in nature, at worst occurring on two days per month. The proposed amendments are considered to have a significant impact on air quality due to the increased and delayed sulfur emission reductions.
Localized Odor Impacts
The proposed inclusion of an Optional Facility Compliance Plan (OFCP) could result in a facility having a reportable sulfur content limit equivalent to 40 ppm overall while still having localized emissions of sulfur at such a level as to result in odor impacts on or off site. The potential for odor problems as a result of the OFCP facility bubbling option is not, however, considered significant. The OFCP must be approved by CARB and EPA as well as the Executive Officer of the SCAQMD prior to implementation. As part of the OFCP application process the operator must identify the estimated emission of sulfur expected from each piece of equipment as well as a description of the equipment and its location. The OFCP will not be approved if the sulfur emissions and location indicate the potential for an odor nuisance to occur. Furthermore, all facilities will remain subject to the provisions of SCAQMD Rule 402 - Nuisance.
Localized Sulfur Impact from the Purchase of non-Compliant Fuel
One provision of the rule amendments allows for the purchase of higher sulfur-containing fuel by a non-RECLAIM facility from a RECLAIM facility not subject to the provisions of Rule 431.1. In this transaction the RECLAIM facility must account for any SOx emissions in excess of the 40 ppm limit and include these emissions in their Allocation. This exchange does not generate additional SOx emissions as the fuel would eventually be used regardless. Rather, the provision allows for the transfer of these fuels from one facility in the Basin to another, which could create potential localized impacts.
In order to be able to utilize the provisions of this amendment, a facility would need a pipeline connected from the seller to the buyer. There are only three refineries in the South Coast Air Basin with the potential to use this provision of Rule 431.1, only one of which actually sells fuel gas at a sulfur limit higher than 40 ppm. It is unlikely that the other two facilities would alter their fuel gas production and sell gas of a higher ppm limit than they are currently producing.
Presently, Chevron Refinery in El Segundo has a pipeline set up to transport its excess gas to Southern California Edison, which is also located in El Segundo. The gas in excess of 40 ppm sulfur that Chevron currently sells to Edison is an unusable by-product of its operations. The Chevron and Edison facilities are no more than one mile away from one another. It is not anticipated that Chevron will have any additional buyers in the near future due to the cost of constructing a pipeline to another facility. The Mobil refinery located in Torrance is currently selling its excess fuel gas to Edison's Redondo Beach facility, and Shell Oil in Huntington Beach is currently selling fuel gas to Edison's Huntington Beach facility. The Mobil and Shell gas sold to Edison has never exceeded the 40 ppm limit. Under the provisions of the amendment, however, the sulfur content could be exceeded, thereby causing shift in emissions in the immediate area. Any potential increase in emissions due to the sale of higher sulfur content fuel while shifted slightly would not be transported to a different region. Under the proposed amendments the RECLAIM facilities would have to account for the additional SOx emissions and could risk exceeding their RECLAIM Allocation or not meeting their annual emission reduction. This impact is considered insignificant prior to mitigation.
PROJECT-SPECIFIC MITIGATION: Because the proposed amendments will result in a loss of future SOx emission reductions and potential increases in current SOx emissions that exceed the SCAQMD SOx significance threshold of 150 pounds per day, the air quality impact of the proposed amendments is considered significant.
There are no feasible mitigation measures available for the increase in SOx emissions due to this proposed amendment that would still meet the project objective. The emission reduction requirements outlined in Rule 431.1 in 1990 were considered feasible at the time of adoption. After research was conducted, however, it was determined that the 40 ppm limit could not be met by landfills until technology could be better examined and developed.
CUMULATIVE IMPACTS: There could be cumulative impacts associated with the proposed amendments since the amendments would delay the SOx emission reductions associated with the current rule. This delay could result in the Basin not attaining the NAAQS for SOx in a timely manner. In addition to the rules and regulations currently being enforced to reduce SOx emissions, there are numerous control measures included in the 1994 AQMP which will further reduce SOx emissions in the future. Emission reductions lost or delayed due to the proposed amendments may be obtained through alternative measures and rules which will contribute to the attainment and maintenance of state and federal ambient air quality standards.
CUMULATIVE IMPACTS MITIGATION: None required beyond implementation of the 1994 AQMP.
ENVIRONMENTAL IMPACTS FOUND NOT TO BE SIGNIFICANT
The environmental topics in the following subsections were analyzed in the Environmental Checklist (Appendix A) to determine if proposed Amended Rule 431.1 could create significant adverse impacts in any of these areas. For all environmental topics discussed below, no significant adverse direct or indirect impacts were identified.
Land Use and Planning
The proposed amendments will have no impact on general plan designation or zoning, agricultural resources, environmental plans, or established communities. The amendments seek to extend the deadline for the 40 ppm SOx compliance limit for landfill gas. The amendments apply to existing emission sources and will have no impact on future land use or planning.
Population and Housing
There are no provisions in the amendments that would affect current or anticipated population or housing. The amendments apply to the production, sale and use of gaseous fuel, and will have no bearing on population or housing.
Geophysical
The amendments will not adversely impact any geophysical condition in the south coast air district. The amendments relate to existing facilities and do not require any type of construction or control equipment in order for implementation. There is no potential for the creation of landslides or mudslides, changes in topography, or unstable soil conditions as a result of the amendments.
Water
The amendments to Rule 431.1 will not alter the operating practices of any landfill or refinery in the south coast air district. The amendments extend a compliance deadline and include a provision for the sale of non-compliant fuel gas. There is nothing in the amendments that would affect water quality or consumption.
Transportation/Circulation
There will be no increase in vehicle trips, impacts on parking, or conflicts with adopted policies associated with alternative transportation as a result of the proposed amendments. The amendments will not alter the policies or operating practices at any of the facilities, therefore, there is no potential for additional trip generation or traffic congestion.
Biological Resources
There are no natural communities or migration corridors that could be impacted by the proposed amendments. The amendments apply to existing facilities and will not affect biological resources.
Energy and Mineral Resources
While the amendments pertain to landfill gas, fuel gas, and the transfer of these resources, there is no potential for a conflict with adopted energy conservation plans. Further, the amendments will not use or deplete any non-renewable resources in a wasteful manner.
Hazards
The proposal will not involve a potential risk of explosion or accidental release of a hazardous material nor would it interfere with an emergency response plan or evacuation plan. The amendments apply to gaseous fuels but do not increase the use, transport, or potential explosion of these fuels.
Noise
There are no noise impacts associated with the proposed amendments. The amendments will not increase noise above currently existing levels.
Public Services
The amendments grant an extension of a compliance deadline and provide additional administrative amendments. There will be no public services impacts as a result of the amendments.
Utilities and Service Systems
The amendments will greatly assist utilities and services systems, such as landfills and refineries. The compliance deadline extension will give landfills additional time to research appropriate control methods. The provision for allowing the sale of non-compliant fuel gas to non-RECLAIM facilities will assist those buying and selling the commodity.
Aesthetics
The amendments will not create an aesthetic impact in any manner. There will be no obstruction of a scenic vista, nor will any light or glare be created. The amendments have no potential to impact aesthetics in the District.
Cultural Resources
There will be no land use disruption, construction, or excavation as a result of the proposed amendments. There is no possibility that cultural resources could be impacted as a result of the amendments.
Recreation
There will be no recreation impacts as a result of the proposed amendments for the reason cited above under "Cultural Resources."
Economics
State CEQA Guidelines Section 15064(f) states the following:
"Economic or social changes resulting from a project shall not be treated as significant effects on the environment. Economic or social changes may be used, however, to determine that a physical change shall be regarded as a significant effect on the environment. Where a physical change is caused by economic or social effects of a project, the physical change may be regarded as a significant effect in the same manner as any other physical change resulting from the project."
The proposed amendments are not expected to result in any changes
in economic or social conditions that could have adverse secondary
impacts on the environment.
A P P E N D I X A
E N V I R O N M E N T A L C H E C K L I S T
Introduction
General Information
Potentially Significant Environmental Impacts
Determination
INTRODUCTION
The environmental checklist provides a standard evaluation tool to identify a project's adverse environmental impacts. A sample checklist form is provided in the State CEQA Guidelines, Appendix I. The SCAQMD has slightly modified the Appendix I checklist, but it still addresses all areas identified in the Appendix I checklist. This checklist identifies and evaluates potential adverse environmental impacts that may be created by the proposed project.
GENERAL INFORMATION
Name of Proponent: South Coast Air Quality Management District
Address of Proponent: 21865 E. Copley Drive
Diamond Bar, CA 91765
Lead Agency: South Coast Air Quality Management District
Name of Project: Proposed Amended Rule 431.1
POTENTIALLY SIGNIFICANT IMPACT AREAS
The following environmental impact areas are determined to be affected by the proposed project. As indicated by the checklist on the following pages, environmental topics marked with an "X" may be adversely affected by the proposed project. An explanation relative to the determination of each of the areas checked below can be found in Chapter 2 - Environmental Assessment.
X Air Quality Public Services Utilities
and Service
Systems
Water Land Use and X Mandatory Findings of
Planning Significance
Geophysical Biological Resources Cultural Resources
Hazards Noise Recreation
Transportation Aesthetics Energy and Mineral
Resources
DETERMINATION
On the basis of this initial evaluation:
I find the proposed project, in accordance with those findings made pursuant to CEQA Guideline Section 15252, COULD NOT have a significant effect on the environment, and that a NEGATIVE DECLARATION will be prepared.
I find that although the proposed project could have a significant effect on the environment, there will not be significant effects in this case because the mitigation measures described on an attached sheet have been added to the project. A MITIGATED NEGATIVE DECLARATION will be prepared.
X I find that the project MAY have a significant effect(s) on the environment, and an ENVIRONMENTAL IMPACT REPORT will be prepared.
Date: Signature: Cindy Greenwald, J.D.
Planning Manager
Potentially No
Significant Impact
Impact
I. LAND USE AND PLANNING. Would the proposal:
a) Conflict with general plan designation or zoning? X
b) Conflict with applicable environmental plans or
policies adopted by agencies with jurisdiction over
the project? X
c) Affect agricultural resources or operations (e.g.
impacts to soils or farmlands, or impacts from
incompatible land uses)? X
d) Disrupt or divide the physical arrangements of an
established community (including a low-income or
minority community)? X
II. POPULATION AND HOUSING. Would the proposal:
a) Cumulatively exceed official regional or local
population projections? X
b) Induce substantial growth in an area either
directly or indirectly (e.g. through projects in
an undeveloped area or extension of major
infrastructure)? X
c) Displace existing housing, especially affordable
housing? X
III. GEOPHYSICAL. Would the proposal result in or expose people to potential impacts involving:
a) Seismicity: fault rupture, ground shaking, seiche or
tsunami? X
b) Landslides or mudslides? X
c) Erosion, changes in topography or unstable soil conditions
from excavation, grading or fill? X
d) Subsidence of land? X
Potentially No
Significant Impact
Impact
IV. WATER. Would the proposal result in:
a) Changes in adsorption rates, drainage patterns, or
the rate and amount of surface runoff? X
b) Exposure of people or property to water related
hazards such as flooding? X
c) Discharge into surface waters or other alteration
of surface water quality (e.g. temperature,
dissolved oxygen or turbidity? X
d) Changes in the amount of surface water in any water
body? X
e) Changes in currents, or the course or direction of
water movements? X
f) Change in the quantity of ground waters, either
through direction additions or withdrawals, or
through interception of an aquifer by cuts or
excavations? X
g) Altered direction or rate of flow of groundwater? X
h) Impacts to groundwater quality? X
i) A need for new water treatment, distribution, sewer
or storm water drainage systems? X
V. AIR QUALITY. Would the proposal:
a) Violate any air quality standard or contribute to an
existing or projected air quality violation? X
b) Expose sensitive receptors to pollutants? X
c) Alter air movement, moisture, or temperature, or
cause any change in climate? X
d) Create Objectionable odors? X
e) Diminish an existing air quality rule or future
compliance requirement resulting in a significant
increase in air pollutant(s). X
Potentially No
Significant Impact
Impact
VI. TRANSPORTATION/CIRCULATION. Would the proposal result in:
a) Increased vehicle trips or traffic congestion? X
b) Hazards to safety from design features (e.g. sharp
curves or dangerous intersections) or incompatible
uses (e.g. farm equipment)? X
c) Inadequate emergency access or access to nearby uses? X
d) Insufficient parking capacity on-site or off-site? X
e) Hazards or barriers for pedestrians or bicyclists? X
f) Conflicts with adopted policies supporting alternative
transportation (e.g. bus turnouts, bicycle racks)? X
g) Rail, waterborne or air traffic impacts? X
VII. BIOLOGICAL RESOURCES. Would the proposal result in impacts to:
a) Locally designated natural communities (e.g. oak
forest, coastal habitat, etc.)? X
b) Wildlife dispersal or migration corridors? X
VIII. ENERGY AND MINERAL RESOURCES. Would the proposal:
a) Conflict with adopted energy conservation plans? X
b) Use non-renewable resources in a wasteful and
inefficient manner? X
IX. HAZARDS. Would the proposal involve:
a) A risk of accidental explosion or release of
hazardous substances (including, but not limited to:
oil, pesticides, chemicals or radiation)? X
b) Possible interference with an emergency response
plan or emergency evacuation plan? X
c) The creation of any health hazards or potential
health hazard? X
Potentially No
Significant Impact
Impact
d) Exposure of people to existing sources of potential
health hazards? X
e) Increased fire hazard in areas with flammable brush,
grass, or trees? X
X. NOISE. Would the proposal result in:
a) Increases in existing noise levels? X
b) Exposure of people to severe noise levels? X
IX. PUBLIC SERVICES. Would the proposal have an effect upon, or result in a need for new or altered government services in any of the following areas?
a) Fire protection? X
b) Police protection? X
c) Schools? X
d) Maintenance of public facilities, including roads? X
e) Other governmental service? X
XII. UTILITIES AND SERVICE SYSTEMS. Would the proposal result in a need for new systems, or substantial alterations to the following utilities:
a) Power or natural gas? X
b) Communications systems? X
c) Landfills? X
XIII. AESTHETICS. Would the proposal:
a) Affect a scenic vista or scenic highway? X
b) Have a demonstrable negative aesthetic effect? X
c) Create light or glare? X
Potentially No
Significant Impact
Impact
XIV. CULTURAL RESOURCES. Would the proposal:
a) Disturb paleontological resources? X
b) Disturb archaeological resources? X
c) Have the potential to cause a physical change which
would affect unique ethnic cultural values? X
XV. RECREATION. Would the proposal:
a) Increase the demand for neighborhood or regional
parks or other recreational facilities? X
b) Affect existing recreational opportunities? X
XVI. MANDATORY FINDINGS OF SIGNIFICANCE.
a) Does the project have the potential to degrade the
quality of the environment, substantially reduce the
habitat of a fish or wildlife species, cause a fish
or wildlife population to drop below self-sustaining
levels, threaten to eliminate a plant or animal
community, reduce the number or restrict the range of
a rare or endangered plant or animal or eliminate
important examples of the major periods of California
history or prehistory? X
b) Does the project have the potential to achieve short-term,
to the disadvantage of long-term, environmental goals? X
c) Does the project have impacts that are individually
limited, but cumulatively considerable?
("Cumulatively considerable" means that the incremental
effects of a project are considerable when viewed in
connection with the effects of past projects, the effects
of other current projects, and the effects of probable
future projects)
d) Does the project have environmental effects which will
cause substantial adverse effects on human beings,
either directly or indirectly? X