October 13, 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.
Regulatory History
Prior to a January 1982 amendment, the rule had limits for total sulfur of 80 parts per million (ppm) for some gaseous fuels sold and 800 ppm for gaseous fuels burned on-site. In January 1982, Rule 431.1 was amended to expand the coverage of the rule to limit total sulfur for biogases (sewage digester and landfill gases) sold or burned on-site to 250 ppm and 800 ppm, respectively.
In May 1990, Rule 431.1 was amended to implement an additional AQMP control measure by providing a single total sulfur limit of 40 ppm for all gaseous fuels sold or burned 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 total SOx emissions at the stack. Because of the unavailability of the continuous total sulfur monitors, the rule was once more amended in October 1992, to extend the compliance date for all gaseous fuels to 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 to May 4, 1996.
Not all of the facilities subject to Rule 431.1 complied 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 which were included in RECLAIM SOx universe did not have to comply with certain command-and-control regulations, such as Rule 431.1. The RECLAIM SOx facilities that were no longer subject to Rule 341.1 mainly included refineries. However, with the exception of certain landfills, all other non-RECLAIM SOx facilities 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, not all of the landfills could 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 control sulfur compounds present in landfill gas. This resulted in variance proceedings for several of the landfill facilities. These variances were granted and are in most part due to expire at the end of this year. Staff recommends that Rule 431.1 be amended to provide additional time for affected facilities to meet the 40 ppm total sulfur limit.
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. The seller is not prohibited from selling its fuel gas, but Rule 431.1 does not allow the non-RECLAIM SOx facility to buy and/or burn this non-compliant gas in its equipment. Therefore, both RECLAIM and non-RECLAIM sources have requested an exemption to allow the non-RECLAIM sources to continue to purchase and burn such non-compliant gas. Staff agrees and recommends that Rule 431.1 be amended to allow for this sale, purchase and use of non-compliant gas.
Third, the sewage treatment and landfill facilities requested additional flexibility to comply with the rule by increasing the averaging period for total sulfur limit. Since the existing rule has a four-hour average sulfur limit, short term variations in biogas production could result in non-compliance periods. The increased averaging period will allow the facilities to better handle variations in the sulfur levels in biogases produced during process upsets and could result in potential cost savings. Staff agrees and recommends that Rule 431.1 be amended to increase the sulfur limit averaging period.
Finally, the October 1992 amendment included an extension of the compliance date for small refiners from May 1994 to May 1996. During rule development for that amendment an interim sulfur limit was inadvertently omitted. This current amendment cures that omission by now incorporating it into this proposal.
The main changes to Rule 431.1 are summarized as follows:
Other proposed changes are minor and are added to clarify and improve the enforceability of the rule.
CEQA and Socioeconomic Analyses
Pursuant to the California Environmental Quality Act (CEQA), the AQMD prepared a Draft Supplemental Environmental Assessment (EA) to the March 1990 EA for Rule 431.1 - Sulfur Content of Gaseous Fuels, and Rule 431.2 - Sulfur Content of Liquid Fuels, for the proposed amendments to Rule 431.1. The Draft Supplemental EA was circulated for a 45-day public review and comment period, which ended September 1, 1995. There were no comments received on the Draft Supplemental EA. The Final Supplemental EA is included in this Final Rule Package.
Due to the bulk of the previously prepared CEQA documents for Rule 431.1, the previous CEQA documents have been distributed to Board members only. Those wishing to view the referenced previous CEQA documents may do so by contacting the AQMD's Public Information Center at (909) 396-3600.
In addition, the AQMD prepared a Draft Socioeconomic Assessment as part of the draft staff report, which addresses the socioeconomic impacts of the proposed amendments to Rule 431.1. The Final Socioeconomic Assessment is included as part of the final 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 to amend Rule 431.1 on October 13, 1995, was set on August 11, 1995. As per the Notice of Public Hearing, written comments were accepted through August 29, 1995. All written comments received by that date were reviewed and responded to by staff in the final staff report which is part of this Public Hearing package for the rule amendment. As a result of the comments received on the proposed rule, staff now proposes additional changes to Proposed Amended Rule 431.1. These changes, however, are administrative in nature and do not affect either the CEQA or Socioeconomic Assessment which were done without an assessment of these minor changes.
THEREFORE, IT IS RECOMMENDED THAT YOUR BOARD
--Certify the Final Supplemental Environmental Assessment for the proposed amendments to Rule 431.1 - Sulfur Content of Gaseous Fuels, in accordance with the attached Resolution.
--Amend Rule 431.1 - Sulfur Content of Gaseous Fuels as proposed in accordance with the attached Resolution.
Respectfully,
James M. Lents, Ph.D.
Executive Officer
Attachments
PL:CC:MN:LB
(blt4311)