UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document

for

EPA ’ s Direct Final Rulemaking

for the California State Implementation Plan

Antelope Valley Air Qualit y Management

Rule 431.1 Sulfur Content o f Gaseous Fuels

Prepared by: Stanley Tong

June 2013− 2

− RULE IDENTIFICATION

-

Agency: Antelope Valley Air Quality Management District ( AV AQMD)

SIP Approved Rule: South Coast Air Quality Management District (SCAQMD)

Rule 43 1.1

– Sulfur Content of Gaseous Fuels

A mended

– May 6, 1983

Submitted

– July 19, 1983 EPA Approved

– October 19, 1984 ( 49 FR 41028)

Superseded Submittal: SCAQMD Rule 431.1

– Sulfur Content of Gaseous Fuels

A mended

– November 17, 1995 (South Coast A QMD)

Submitted

– January 31, 1996

Subject of this TSD: AVAQMD Rule 431.1

– Sulfur Content of Gaseous Fuels

Amended

– August 21

, 2012

Submitted

– April 22, 2013

BACKGROUND

– On July 1, 1997 the Antelope Valley Air Pollution Control District (AVAPC D) was formed and assumed all air pollution control responsibilities from the South Coast Air Quality Management District (SCAQMD) for the areas of Los Angeles County outside the South Coast Air Basin. 1 All SCAQMD rules in effect at the time

, including Rul e 431.1, remain ed in effect under the newly formed AVAPCD. On January 1, 2002, the Antelope Valley Air Quality Management District (AVAQMD) replaced the

AVAPCD.

Rule 431.1, Sulfur Content of Gaseous Fuels, limits the sulfur content of fuels such as

landf ill gases, sewage digester gases

, refinery gases and other gas eous fuels

. On October 19, 1984 (49 FR 41028) w e approved SCAQMD Rule 431.1 into the SIP

. At that time, sulfur limits in SIP approved Rule 431.1 were : 1) 800 parts per million ( ppm ) as hydrogen sulfide for burning or discharge to any fuel gas system/vent gas disposal
system; 2) 250 ppm for selling any landfill or sewage digester gases ; and 3) 80 ppm for selling of all other gases. These SIP approved limits became a part of AVAQMD's SIP

until such time the District amended the rule and those amendments were approved

into the SIP.

SCAQMD amended Rule 431.1 s everal times between 1983 and 1997, p rior to the

formation of AVAQMD, but o nly the 1995 amendments were submitted for SIP approval. Since Antel ope Valley separated from South Coast in 1997 and EPA had not approved the 1995 amendments for Rule 431.1 into the SIP prior to its separation, t he

1983 amendments for Rule 431.1 continue to be the applicable SIP rule for AVAQMD.

1 Antelop e Valley Air Quality Management District, Final Staff Report, Amendment to Rule 431.1

– Sulfur Content of Gaseous Fuels, Adopted on 08/21/2012 , page 1.− 3

− AVAQMD ’s current submitt al updates the rule to more closely match the current version

of SCAQMD Rule 431.1 (amended June 12, 1998) . It amend s rule language , updat es SO 2 limits, and delet es obsolete exemptions . It also adds new sections describing the rule’s purpose, and specifies monitoring, reporting and recordkeeping requirements and

authorized test methods.

AVAQMD's staff report states that some landfill operators have been unable to cost effectively m ee t Rule 431.1's sulfur limit of 40 ppm and have entered into compliance

agr eements with the District

. 2 The current amendment re verts the 40 ppm locally

enforced limit back to the 250 ppm SIP limit for sulfur emissions from landfill gas

.

RULE SUMMARY

- Rule 431.1 limits the sulfur content of gaseous fuels. Its purpose is

to reduc e emissions of sulfur oxides from the combustion of landfill, sewage digester, refinery

, and other gases. W e compared the submitted rule against the SIP approved

rule a mended on May 6 , 1983. The 2012 amended rule:

1. A pplies to the burning, transferring, sel ling, or offering for sale of any gaseous fuel containing sulfur compounds in excess of 16 ppm calculated as hydrogen sulfide in stationary equipment requiring a permit to operate in the AVAQMD

.

2. Adds s ections to specify the purpose, applicability, monitor ing requirements, reporting and recordkeeping requirements, and test methods.

3. Revises the sulfur limits as follows:

4. Add s requirements for : continuous emission monitoring system s (CE MS) used to

determine SOx emissions after burning a fuel ; and for continuous fuel gas monitoring system s (CFGMS) used to monitor the sulfur content of a fuel prior to burning it . Add s an option for landfills and sewage digesters to use an alternative

2 AVAQMD Final Staff Report, Amendment to Rule 431.1

– Sulfur Content of Gaseous Fuels, Adopted on

8/21/ 12, page 2. 5/6/1983 SIP Rule 8/21/ 20 12 Amendments

Selling gaseous fuels other than landfill/sewage digester

gases 80 ppm 40 ppm 4

- hr average

Sellin g landfill gas 250 ppm 250 ppm daily average Selling s ewage digester gas 250 ppm 40 ppm daily average OR 40 ppm monthly average and 500 ppm 15

- minute average
Burn ing or discharg ing to any fuel gas system/vent gas disposal system 800 ppm Refinery gas: 4 0 ppm 4

- hr average Landfill gas : 250 ppm daily avg. Sewage Digester gas: 40 ppm daily average OR 40 ppm monthly average and 500 ppm 15

- minute average Other gases 40ppm 4

- hr average− 4

− monit oring method provided the alternative monitoring method has been approved by the District, California Air Resources Board and US EPA.

5. Lower s the sulfur emissions threshold for facilities to be considered exempt. The previous SIP approved rule exempted fa cilities with emissions less than 30 pounds per day. The current submittal reduces this to 5 pounds per day of total sulfur compounds calculated as hydrogen sulfide.

6. R emov e s exemptions for:

a. Fluid catalytic cr acking unit regeneration gases ( Rule 1105 re scinded 4/21/98)

.

b. Combined unit gases from an air pollution control s ystem for steam drive oil

wells (Rule 1148 rescinded 1/20/98 ).

c . Gase s vented duri ng refinery turnaround (Rule 1123 rescinded 11/1 7 /97)

d . Gases vented to a control system ( Rule 46 6 rescinded 6/17/08)

e . Gaseous fuels from which the gaseous products of combustion are used as raw materials for other processes.

f . Vent gas streams, excluding coker blowdown, which have been connected to fuel gas or vent gas disposal systems.

EVALUA TION CRITERIA

- The following document was used to evaluate the submitted

rule

.

1

. SO 2 Guideline Document EPA

- 452/R

- 94

- 008, February 1994.

EPA EVALUATION

- A summary of our evaluation follows.

1. The submitted rule was evaluated for consistency with th e Clean Air Act and US EPA rulemaking policy as outlined in SO 2 Guideline Document EPA

- 452/R

- 94

- 008, February 1994.

2. AVAQMD , which is within the Mojave Desert Air Basin and Los Angeles County

, is in attainment 3 for the 19 71 140 ppb SO 2 24

- hour primary s tandard and 30 ppb

annual standard. Th e primary standard was revised on June 22, 2010 ( 75 FR

35520 ) t o 75 ppb for 1

- hour daily maximum conce ntrations averaged over 3

years

. 4

3 40 CFR 81 .305, July 1, 2012 edition.

4 1

- hour standard is the 3

- year average of the 99th percentile of the yearly distribution of 1

- hour daily

maximum SO 2 concentrations. ( http://www.epa.gov/ttnnaaqs/standards/so2/s_so2_history.html )− 5

− 3. On June 20, 2011, California submitted its recommendation that the Mojave Desert Air Basin, including Antelope Valley, be designated "attainment" for the

2010 SO 2 1

- hour primary standard. California's submittal states that ambient air quality monitoring i n the Mojave Desert Air Basin shows a 2009 1

- hour SO 2 design value of 10 ppb, well below the federal standard of 75 ppb.

The California Air Resources Board ( CARB ) also states there have been no

violations of the federal 1

- hour SO 2 standard measured over the last two decades, and violations are not expected to occur in the future. 5

4

. A review of the air quality statistic s report s 6 for 2009

– 2012 indicates ambient

SO 2 concentrations of 12

– 25 ppb for Los Angeles C ounty . These concentrations

are below the 19 71 and 2010 primary SO 2 federal standard s

.

In a February 6, 2013 letter from EPA Region 9 to California, we state that “EPA’s review of the most recent monitored air quality data from 2009

– 2011 shows no

violations of the 2010 SO 2 standard in any areas in California.” At this time, EPA is not designating areas of California for the 2010 primary SO 2 National Ambient Air Quality Standard s

.

5

. AVAQMD 's staff report states the 2012 amendment s re vert s Rule 431.1's 40 ppm landfill gas sulfur limit back to 250 ppm for the sale of landfill gas

. The District

states this is not a relaxation of the SIP because the current SIP limit is 250 ppm and the amendment contains similar requirements as found in SCAQMD Rule
431.1 amended June 12, 1998

. 7

As shown und er the Rule Summary section above, the current SIP approved

limits for sulfur compounds is 80

- 250 ppm for the selling of gaseo us fuel and up to 800 ppm sulfur for burning or discharge of fuel. AVAQMD's 40 ppm limit is a locally adopted limit that ha d not b een submitted by AVAQMD for SIP approval

.

T he amended rule reduces the sulfur limit for selling sewage digester gas from 250 ppm down to (1) 40 ppm (daily average) or (2) 40 ppm (monthly average) and

u p to 5 00 ppm averaged over 15 minute s

. The first opt ion, a 40 ppm daily average, is clearly more stringent than the existing 250 ppm SIP limit. The second option, a 40 ppm monthly average combined with a 500 ppm 15

- minute average allows short term intermittent emissions to exceed the existing 250 ppm SIP li mit. We do not believe the short term 500 ppm 15

- minute average would adversely impact the District's ability to maintain the SO 2 National Ambient Air Quality Standard ( NAAQS ) for the following reasons:

5 Letter from CARB (James Goldsten e ) to US EPA Region 9 (Jared Blumenfeld) dated June 20, 2011, page A

- 32

6 http:/ /www.epa.gov/airquality/airdata/ad_rep_con.html

7 AVAQMD Final Staff Report, Amendment to Rule 431.1

– Sulfur Content of Gaseous Fuels, Adopted on 8/21/12, page 13.− 6

− 1) a 40 ppm monthly average effectively limits a facility from emitting 500

ppm more than two days per month before it will exceed the 40 ppm monthly average limit;

2) District staff indicated there are two publicly owned treatment works and to their knowledge, the sewage digester gases are burne d or flared (800 ppm existing SIP limit) and are not sold (250 ppm existing SIP limit) 8 ; and

3) AVAQMD is in attainment for the 1971 primary SO 2 NAAQS, and California points out that for the 2010 SO 2 primary standard, ambient air quality monitoring in the Mojave Desert Air Basin shows a 2009 1

- hour SO 2 design value of 10 ppb, well below the 2010 federal standard of 75 ppb

and that there have been no violations of the federal 1

- hour SO 2 standard
measured over the last two decades, and violations ar e not expected in the

future. 9 Since AVAQMD is in attainment for the SO 2 NAAQS, Rule 431.1 is not a required SIP submittal.

6. Our r eview of Rule s 431.1 for SCAQMD and AVAQMD indicates the other sulfur

limits are identical between the two air districts except for the landfill gas
category. AVAQMD 's amendment limits the daily average landfill sulfur gas eous
emissions to 250 ppm compared to SCAQMD's 150 ppm limit

. AVAQMD's staff
report includes an analysis demonstrating it i s not cost effective to install controls

to reduce emissions to below 150 ppm. 10 Other sulfur limits were strengthened from the previous SIP approved rule.

7. AVAQMD estimates a maximum SOx emissions shortfall of approximately 10 pounds per day (~2 tons per year) when reverting the local ly adopted 40 ppm limit

back to 2 50 ppm. Since the existing SIP limit is 250 ppm, we do not consider this

a SIP relaxation.

8

. On O ctober 14, 2011 and April 26, 2012 EPA submitted comments to AVAQMD 's

draft amendments to Rule 431.1. We generally accept A VAQMD's re sponses and clarifications to our comments and highlight two areas below for further

discussion.

a. Our October 14, 2011 letter recommended including language to limit the number

of allowed breakdowns for CEMS and CFGMS

.

AVAQMD respon ded tha t excess breakdowns would be prevented by a facility's operating permit because CEMS and CFGMS are required to be maintained in

8 P ersonal communications Chris Anderson (AVAQMD) and Stanley Tong (EPA Reg ion 9) 6/26 / 13.

9 Letter from the California Air Resources Board (James Goldsten e ) to EPA Region 9 (Jared Blumenfeld) dated June 20, 2011, Page A24

- 32.

10 AVAQMD Final Staff Report, Amendment to Rule 431.1

– Sulfur Content of Gaseous Fuels, Adopted on 8/21/12, page 13 and A ppendix C

.− 7

− good operating condition. We also determined that breakdown of CEMS and

CFGMS sh ould be minimized under Rule 431.1 because conti nuous monitoring systems are subject to Rules 218 and 218.1 which require them to have a 95% availability

.

Suggestion for Future Evaluation:

b. Our letter of April 26, 2012 recommended revisiting the Best Available Control Technology (BACT) analysis at a later date to consider whether or not carbon adsorption being tested under Puente Hills Landfill 's Experimental Permit to

Construct is cost effective to meet a 150 ppm limit.

AVAQMD responded that the District may consider carbon adsorption as a possi ble BACT control technology depending on the results of an evaluation of its

use to control H 2 S at the Puente Hills landfill. We are including this discussion as a reminder to evaluate carbon adsorption the next time Rule 431.1 is amended.

EPA ACTION

– T he submitted Rule 431.1 strengthens the SIP by lowering the sulfur emission limits for selling landfill a nd other gases from the 1983 SIP approved rule. It also lowers the sulfur emission limit for the burning of refinery, landfill gas, sewage digester gas and other gases. It slightly increases the limit for s elling sewage digester gases by allowing

a 40 ppm monthly average and 500 ppm 15

- minute average. The District clarifies that sewage digester gases are not sold, but are flared , and that t he limit for t he burning or flaring of these gases is being reduced f rom 800 ppm down to 40 ppm.

AV AQMD states there is a maximum SOx emissions shortfall of approximately 10 pounds per day (~ 2 tons per year ) 11 when changing from a limit of 40 ppm to 250 ppm as Hydrogen Sulfide. The 40 ppm limit, while locally enforceable, is not the SIP approved limit . Th e SIP l imits include 2 50 ppm for selling landfill and sewage digester gases and 800 ppm for burning or discharge of gases , so we do not consider this a SIP

relaxation.

Rule 431.1 is not a required SIP submittal since (a) the District is in attainment for the

19 71 primary SO 2 standard; (b) the ambient SO 2 concentrations from 2009

– 2012 are below the 2010 primary standard; and (c) EPA has not designated areas in Californi a at this time for the 2010 primary SO 2 NAAQS.

The rule largely fulfills the relevant CAA §110 and part D requirements. EPA staff recommends approval of Rule 431.1 pursuant to CAA §110(k)(3) and §301(a).

REFERENCES

- 1

. SO 2 Guideline Document EPA

- 452/ R

- 94

- 008, February 1994. http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=2000H22J.txt

11 AVAQMD Final Staff Report, Amendment to Rule 431.1

– Sulfur Content of Gaseous Fuels, Adopted on 08/21/2012, page C

- 7

.− 8

− 2

. SC AQMD Rule 431.1 Sulfur Content of Gaseous Fuels, amended May 6, 1983

3. AV AQMD Rule 431.1 Su l f ur Content of Gaseous Fuels, amended August 21,

2012.

4

. AVAQMD Final Staff Report, Amendment to Rule 431.1

– Sulfur Content of Gaseous Fuels, Adopted on 8/21/12.

5

. SCAQMD Rule 431.1 Sulfur Content of Gaseous Fuels, amended June 12,

1998.

6

. Letter fr om CARB (James Goldste n e ) to EPA Region 9 (Jared Blumenfeld) dated
June 20, 2011. www.arb. ca .gov/desig/ so2 letr.pdf

7

. Federal Register 75 FR 35520 , Ju ne 22, 2010 Final Rule for SO 2 primary standard of 75 ppb over 1

- hour

.

8. Personal communications Chris Anderson (AVAQMD) and Stanley Tong (EPA Region 9) regarding whether sewage digester gases are sold. 6/26/13.