UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document 

for

EPA’s Notice of Proposed Rulemaking 

for the

California State Implementation Plan

South Coast Air Quality Management District, 

Rule 1127, Emission Reduction from Livestock Waste

Prepared by: La Weeda Ward

January 16, 2013
2

Agency: South Coast Air Quality Management District (SCAQMD)

Submitted Rule: Rule 1127 - Emission Reductions from Livestock Wastes

Submitted – October 5, 2006

Completeness Determination: October 24, 2006

SIP Approved Rule: N/A

I. RULE SUMMARY

South Coast Air Quality Management District (SCAQMD) Rule 1127 was adopted on August 6, 

2004. The purpose of the rule is to reduce emissions of ammonia, volatile organic compounds 

(VOC) and particulate matter under 10 microns (PM10) from dairy livestock waste. Applicable 

operations include dairies, heifer, and calf farms within the SCAQMD’s jurisdiction. The rule

also applies to manure processing operations, such as composting operations and anaerobic 

digesters. 

Rule 1127 was designed to implement the 2003 Air Quality Management Plan (AQMP) control 

measure, WST-01 and establish Best Available Control Measure (BACM) requirements for 

dairies pursuant to Senate Bill 700 (Florez) signed by California governor Gray Davis on 

September 22, 2003, which required applicable non-attainment areas to remove exemptions for 

certain agricultural operations from permitting requirements. EPA is evaluating the rule 

provisions for conformance with reasonable available control technology (RACT) requirements

pursuant to Clean Air Act (CAA) Section 182(b)(2). 

Rule 1127 applies to applicable dairy farms with 50 or more cows, heifers and/or calves and 

includes Best Management Practices (BMPs) for manure disposal and manure processing. Table 

1 summarizes the dairy cow population according to the most recent information from the 

district. There has been a continual decline in both the number of dairies and total number of 

dairy cows since 2002. Table 1 lists base year (2002) and future year dairy cow population, 

based on a district-projected 2% per year decrease.

1

The district also bases the estimated 

emission reductions from these projected dairy cow population figures. The rule evaluation that 

follows assesses the rule effectiveness without regard to decrease and relocation of the dairy cow 

population or the impact of manure disposal requirements pursuant to water quality regulations.

 

1

Reproduced Rule 1127 Staff Report inventory in email communication between Tuyet-Le Pham and La Weeda Ward, 

November 30, 2012. Also see estimated decline in milk production from 1999 to 2009, Technology Assessment – 2007 AQMP 

CM# MCS-05, “Updated Emissions Inventory and Recommendations Regarding Implementation of 2007 AQMP Control 

Measures MCS-05-Emission Reductions from Livestock Waste”, South Coast Air Quality Management District, October 2011

(2011 Technology Assessment), Industry Trends and Projections, pages 6-7.
3

Table 1 – Dairy Cow Population and Projected Decrease

in the South Coast Air Management District Jurisdiction

20022

2004 2006 2008 2010

Milking 

Cows 204,846 196,652 188,458 180,264 172,071 

Dry Cows 36,201 34,753 33,305 31,857 30,409 

Heifers 75,582 72,559 69,535 66,512 63,489 

Calves 77,320 74,227 71,134 68,042 64,949 

Total Cows 393,949 380,195 364,438 348,683 332,928

Following are the major requirements of Rule 1127.

Best Management Practices (BMP)

1. Implement at least one of the following manure harvesting protocols to minimize fugitive 

dust emissions: 

a) Scrape or harrow before 9 a.m. unless the moisture content is greater than 20% (as 

determined by specified test method); OR

b) Clear corrals of manure such that an even surface of compacted manure remains on 

top of the soil. Do not scrape down to soil level; OR

c) Water corral before manure harvesting to reduce dust through increased surface 

moisture. This measure is not required for lactating cows.

2. Minimize excess water in corrals by:

a) Identifying and eliminating water leaks from trough and trough piping: and 

b) Complying with corral drainage standards in the Engineered Waste Management 

Plan.

3. Pave feedlanes at least 8 feet on the corral side of the feedlane fence.

4. Clear corrals of accumulated manure in excess of 3 inches in height at least 4 times per 

year with at least 60 days between clearings.

5. Remove all on-dairy stockpiles within 3 months of the last corral clearing day and no 

more than 3 months after the date that the previous stockpiles were last completely 

cleared. 

Manure Disposal Requirements

Remove or contract to remove manure from the dairy only to:

 

2 Baseline data from Rule 1127 Staff Report, page 9.
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1) A manure processing operation designed to reduce ammonia and VOC emissions from 

unprocessed manure (according to approval requirements as specified in the rule which 

allow one or a combination of anaerobic digester, a composting operated in compliance 

with Rule 1133 and Rule 1133.2; or an alternative composting operation according to 

specific provisions); or 

2) Agricultural land within the SCAQMD approved for the spreading of manure; or 

3) A combination of the above options.

Reporting, Recordkeeping and Test Methods

Reporting and recordkeeping requirements include initial notifications and annual reports to 

include the amount of annual manure removed to various destinations. Test methods for 

measurement of moisture content in manure shall be determined with an electrical conductivity 

or microwave moisture meter, or other method approved by the SCAQMD, California Air 

Resources Board and U.S. EPA. 

II. RULE EVALUATION

Rule 1127 was evaluated on basis of enforceability, stringency, and relaxation.

A. Enforceability - The Bluebook (Issues Relating to VOC Regulation Cutpoints, Deficiencies, 

and Deviations, EPA, May 25, 1988) and the Little Bluebook (Guidance Document for 

Correcting Common VOC & Other Rule Deficiencies, EPA Region 9, August 21, 2001) 

were used to help evaluate compliance with the CAA §110(a)(2)(A) requirement for 

enforceability. Rule 1127 contains provisions that provide for clear, unambiguous and 

measurable testing, monitoring and recordkeeping requirements such that the rule is 

enforceable in practice.

B. Stringency – RACT – CAA Section 182(b)(2) requires moderate areas (and higher level 

non-attainment areas) like SCAQMD to adopt and submit SIP provisions implementing 

Reasonably Available Control Technology (RACT) for all stationary sources of VOC that 

emit more than 10 tons per year of VOC. According to the district, there is at least one dairy

that meets this threshold.

3 RACT is defined as “the lowest emission limitation that a 

particular source can meet using control technology that is reasonably available, considering 

technological and economic feasibility (44 FR 53762, September 17, 1979).” Additionally, 

CAA Section 172(c)(1) requires nonattainment areas to implement all reasonably available 

control measures (RACM), including such reductions in emissions from existing sources in 

the area as may be obtained through the adoption, at a minimum, of RACT, as expeditiously 

as practicable.

There is no federal policy or guidance (e.g., EPA Control Technique or Alternative Control 

Technology Guidelines) describing reasonably available controls for livestock waste. In 

 

3 Email communication between Tracy Goss (SCAQMD) and Wienke Tax, (USEPA Region 9), May 3, 2011. 
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absence of guidance or policy, an evaluation for RACT compliance was done in part by 

comparing Rule 1127 with the level of stringency achieved by the San Joaquin Valley 

Unified Air Pollution Control District (SJVUAPCD) Rule 4570, Confined Animal Facilities,

for control measures that pertain to manure management. EPA approved Rule 4570 as 

meeting RACT in January 2012.4 While such an evaluation is relevant, we note that the 

source operations and District rules have significant differences that make a strict limitationby-limitation comparison difficult. For instance, SJVUAPCD Rule 4570 applies to all types 

of confined animal facilities, while Rule 1127 applies only to dairies. In addition, dairies in 

South Coast are largely dry feed lot operations, 5in contrast with larger diaries in the San 

Joaquin Valley that use flushing and lagoon operations.6 Another difference is the specific 

focus on corral waste control in SCAQMD versus other categories of dairy emissions (e.g.

feed and silage operations, milk parlor, etc.) in SJVUAPCD Rule 4570.

7

In particular, while 

silage is a major dairy VOC source in the San Joaquin Valley, most South Coast dairies do 

not use silage.8Still another major difference is the significantly lower applicability 

threshold for SCAQMD Rule 1127. 

As part of our consideration of RACT, we have compared Rule 1127 with the subset of Rule 

4570 provisions that relate to corral livestock waste.9 Rule 1127 is less stringent than Rule 

4570 where Rule 4570 requires seven measures for managing corral livestock waste while

Rule 1127 requires four of the seven measures. However, that is partly mitigated by 

SCAQMD Rule 223, Emission Reductions for Large Confined Animal Facilities, which 

contains a menu from which operators must select among six options that include the 

remaining three measures.

10 In addition, Rule 1127 is significantly more stringent than Rule 

4570 in its minimum regulatory threshold of 50 cows, heifers and/or calves compared to 

Rule 1127’s threshold of 500 milk cows or 7,500 heifers, calves and/or other support 

stock.

11

Rules 4570 and 1127 are similar in terms of projected percent of emission reductions 

achieved related to manure management in corrals, with SCAQMD projecting a slightly 

greater percent reduction. Table 2 lists the actual and projected future-year emissions 

 

4

SJVUAPCD Rule 4570 Confined Animal Facilities (Adopted June 15, 2006; Readopted June 18, 2009; Amended October 21, 

2010) Approved January 17, 2012, 77 FR 2228.

5

SCAQMD Rule 1127 Staff Report, page 9.

6

 Rule 4570 Staff Report, VII, A. page 9.

7

SCAQMD Rule 223 Emission Reduction Permits for Large Confined Animal Facilities is similar to SJVUAPCD Rule 4570 in 

this regard. Rule 223 is currently in effect in the district and was submitted to EPA for approval on March 17, 2009. 

8

“...In the Basin, much of the feed is dried, bailed, and shipped to local dairies, as opposed to adjacent farming. This feed, 

including grains, has extremely low moisture content, and thus negligible VOC emissions from the feed itself. In addition, 

according to a Milk Producers Council representative, approximately 10% of the dairy farms in the Basin grow their own silage, 

which is stored in bags to prevent fermentation and retain nutrients. The silage bags are kept on-site for only a few days at a time. 

Dairymen who purchase feed (silage, alfalfa, corn, grain, etc.) on an as-needed-basis also store it on-site for only few days at a 

time, thus minimizing VOC emissions from the facility,” SCAQMD Board Meeting, Agenda No. 22, October 7, 2011, Rule and 

Control Measure Forecast, Attachment E, South Coast Air Quality Management District Technology Assessment– 2007 AQMP 

CM# MCS-05, Updated Emissions Inventory and Recommendations Regarding Implementation of 2007 AQMP Control Measure 

MCS-05 – Emission Reductions from Livestock Waste, page 18, October 2011.

9

See Rule 4570, Table 4.1, E. Corrals.

10 Rule 223, Table 1, D. Corrals.

11 Rule 4570, Section 4.0, Table 2 – CAF Thresholds for Regulation, October 21, 2010. 
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estimates derived by multiplying an emissions factor of 12.8 lb/head/year12,13 by the dairy 

cow population figures. Table 3 lists the emission estimates without the implementation of 

Rule 1127 (e.g., due to the implementation of water quality regulations). Table 4 describes 

the emissions reduction that is due to implementation of Rule 1127 alone (e.g., without the 

impact of relocation and water quality regulations). Emissions reductions from Rule 1127 

implementation alone are only considered when they achieve reductions above and beyond 

the waste disposal requirements required by the Santa Ana Regional Water Quality Control 

Board, and not due to relocation or movement of dairies out of the SCAQMD jurisdiction.14

Table 5 contains a list of baseline and emission reduction rates that SJVUAPCD estimates 

are achieved by Rule 4570 manure management measures also applicable to dairies. As 

described in Table 5, SJVUAPCD achieves 32.3% (which we determined previously met the 

RACT criteria)

15 compared to 34.8% emissions reduction projected for Rule 1127. 

Table 2 - Estimated Emissions Associated with SCAQMD Rule 1127 (tons/day)16

2002 2004 2006 2008 2010

Emissions 6.91 6.63 6.35 6.08 5.80

Table 3 – Emission Estimates from Current Practices in SCAQMD (tons/day) 17,18

2002 2006 2010

Local land application 0.51 0.56 0.49

Out of region 0.66 0.66 0.66

Windrow composting 0.44 ___ ___

Rule 1133.2 Composting ___ 0.02 0.02

Digester ___ 0.14 0.14

VOC Reduction 1.61 1.38 1.31

 

12 The district uses a VOC emission factor of 12.8 lb/head/yr across the board for all types of cows based on a metabolism study 

conducted by Ritzman and Benedict, Rule 1127 Staff Report, page 12.

13 The district justifies the use of this emissions factor in a 2011 Technology Assessment as follows: “District staff believes that 

12.8 lb/head/yr for milking cows is still relevant to the SCAB for the following reasons: (1) there are no known “freestall barn” 

dairies in the SCAB; instead dairies in the Basin are mostly “dry lot corral” facilities; (2) land application of liquid manure is not 

a known practice in the Basin. Without those two sources of emissions, the adjusted SJVAPCD would be 12.6 lbs/head/yr; 

therefore, the 12.8 lbs/head/yr factor that staff is using remains relevant for sources in the District.” 2011 Technology 

Assessment, page 12.

14 On August 20, 1999, the Santa Ana Regional Water Quality Control Board (SARWQCB), re-evaluated the dairy and other 

animal feeding operations and developed Order No. 99-11, which prohibits stockpiling of manure at a dairy for more than 180 

days. SCAQMD Rule 1127 requires four coral cleanings per year which exceeds the two cleanings per year required by 

SARWQCB regulations.

15 EPA approved SJVUAPCD Rule 4570 into the California SIP on January 17, 2012 (77 FR 2228).

16 Reproduced Rule 1127 Staff Report inventory in email communication between Tuyet-Le Pham and La Weeda Ward, 

November 30, 2012.

17 Rule 1127 Staff Report, pages 18-20.

18 Reproduced Rule 1127 Staff Report inventory in email communication between Tuyet-Le Pham and La Weeda Ward, 

November 30, 2012.
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Remaining VOC 5.30 4.97 4.49

Baseline VOC 6.91 6.35 5.80

% Reduction 23.3 21.7 22.6

Table 4 – Emission Estimates from Rule 1127 Implementation Alone (tons/day) 10, 11

2006 2010

Local land application 0.64 0.54

Out of region 0.99 0.99

Windrow composting

Alternative Composting 0.77 0.77

Rule 1133.2 Composting 0.03 0.03

Digester 0.14 0.14

VOC reduction with Rule 1127 2.57 2.47

VOC Remaining with Rule 1127 3.79 3.33 

VOC reduction from Rule 1127 Alone 1.19 1.16

% Reduction from R 1127 Alone 31.3 34.8

Table 5 – Baseline and Emissions Reduction Estimates for SJV Rule 4570

SJ Rule 4570 Manure Management Corral Measures for Dairies Estimated 

Emissions 

Reductions19

1. Pave feedlanes for a width of 8 feet (milk & dry cows) or 6 feet (heifers). ___

2. Clean manure from corrals at least 4 times per year with at least 60 days 

between cleanings or clean corrals at least once between April and July and 

once between September and December. 

___

3. Inspect water pipes and troughs and repair leaks at least once every 7 days. 5%

4. Slope the surface of the corrals a specified percentage or maintain proper 

drainage so as to prevent water from standing more than 48 hours or scrape 

corrals to maintain a dry surface.

___

5. Scrape, vacuum or flush concrete lanes in corrals at least once every day 

(mature cows) or once every 7 days (support stock) or clean concrete lanes so 

manure does not exceed 12 inches at any point or time.

10%

6. For facilities with shade structures, install structures with permeable 

roofing, or uphill of any slope, or with a North/South orientation, or clean 

manure from under shades at least once every 14 days. 

2.3%

7. Managing corrals such that manure depth does not exceed 12 inches. 5%

8. Cover dry manure piles during certain periods 10%

Total % of Emissions Achieved 32.3%

 

19 SJVUAPCD Rule 4570 Staff Report (Appendix B, Table 14), October 21, 2010.
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Based on the foregoing comparison to SJV Rule 4570, SCAQMD’s analysis in support of 

Rule 4570 and consideration of general national RACT policy and precedent, as well as the 

lack of specific state or national guidance regarding RACT for CAFs (e.g., a national 

Control Techniques Guidance or a California Suggested Control Measure), and the lack of 

other more stringent SIP requirements or other evidence demonstrating widely available 

more stringent controls, we conclude that Rule 1127 fulfills the RACT criteria by 

implementing control technology that is reasonably available, considering technological and 

economic feasibility.

C. SIP Relaxation - We have evaluated this SIP revision to determine whether it would 

interfere with any applicable requirement concerning attainment and reasonable further 

progress (RFP) or any other applicable requirement of the Act (CAA §110(l)) or modify, in 

a nonattainment area, any SIP-approved control requirement in effect before November 15, 

1990 (CAA §193). Rule 1127 reduces emissions and strengthens the SIP because there is no 

previous version of the rule in the SIP. Furthermore, it does not undermine other existing 

SIP provisions. Therefore, we propose to determine that an approval of the submittal would 

comply with CAA sections 110(l) and 193 because (1) the proposed SIP revision would not 

interfere with the on-going process for ensuring that requirements for RFP and attainment of 

the National Ambient Air Quality Standards are met, and (2) the submitted SIP revision is 

more stringent than the existing SIP requirements. 

III. Additional Recommendations for Next Rule Revision 

1. Rule 1127 can be improved by adding the following applicable provisions from Rule 223 

(Emission Reduction Permits for Large Confined Animal Facilities)20 directly into Rule 1127 

for large CAFs. These provisions do not affect our determination of RACT for the activities 

addressed by Rule 1127, but would strengthen the rule and clarify requirements for large 

CAFs by including all corral-related waste measures in one rule.

a. Slope the surface of the corrals a specified percentage or maintain proper drainage so 

as to prevent water from standing more than 48 hours or scrape corrals to maintain a 

dry surface.

b. Scrape, vacuum or flush concrete lanes in corrals at least once every day (mature 

cows) or once every 7 days (support stock) or clean concrete lanes so manure does 

not exceed 12 inches at any point or time.

c. For facilities with shade structures, install structures with permeable roofing, or uphill 

of any slope, or with a north/south orientation, or clean manure from under shades at 

least once every 14 days.

d. Manage corrals such that manure depth does not exceed 12 inches or apply lime (or 

similar absorbent material in the corrals or thymol to feedlot soil in accordance with 

the manufacturer’s recommendation.

2. While we understand that VOC emissions from other CAF activities (e.g., feed and silage 

operations, milk parlor, etc.) are addressed in SCAQMD Rule 223, we encourage you to 

 

20 SCAQMD Rule 223 establishes permit requirements for Large CAF dairy and poultry operations.
9

consider moving all controls affecting CAFs into SCAQMD Rule 1127 to simplify and 

streamline requirements for sources, regulators and the public. While we also understand 

that silage is used much less in SCAQMD than in SJVUAPCD, we encourage you to 

consider adopting SJVUAPCD's more stringent silage controls21 in South Coast to the extent 

that silage is used.

3. Section (f)(3)(A)(i) requires the use of in-vessel compost systems but the rule does not define 

this term. SCAQMD should insert a definition for in-vessel compost systems to improve 

enforceability of rule requirements.

IV. EPA Action

Rule 1127 is enforceable, strengthens the SIP, and meets CAA requirements for RACT. 

Therefore, EPA staff recommends approval of Rule 1127. 

V. References 

1. SCAQMD Rule 1127, Emission Reductions from Livestock Waste, adopted August 6, 

2004. 

2. “Draft Final Staff Report, Proposed Rule 1127 – Emission Reductions from Livestock 

Waste,” SCAQMD, August 6, 2004. 

3. Technology Assessment – 2007 AQMP CM# MCS-05, “Updated Emissions Inventory 

and Recommendations Regarding Implementation of 2007 AQMP Control Measures 

MCS-05-Emission Reductions from Livestock Waste”, South Coast Air Quality 

Management District, October 2011.

4. California Senate Bill 700 (Florez), “Air quality: emissions: stationary sources:

agricultural operations,” signed by California Governor Gray Davis, September 22, 2003.

5. “California Regional Water Quality Control Board, Santa Ana Region, “General Waste 

Requirements for Concentrated Animal Feeding Operations (Dairies and Related 

Facilities) within the Santa Ana Region. Order No. 99-11, NPDES No. CAG018001,” 

August 20, 1999.

6. Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations,” (Bluebook) 

EPA OAQPS, May 25, 1988.

7. “Guidance Document for Correcting Common VOC & Other Rule Deficiencies,” (Little 

Bluebook), EPA Region 9, August 21, 2001. 

8. Portions of the proposed post-1987 ozone and carbon monoxide policy that concern 

RACT, 52 FR 45044, November 24, 1987.

9. “State Implementation Plans, General Preamble for the Implementation of Title I of the 

Clean Air Amendments of 1990” 57 FR 13498, April 16, 1992.

10. “Preamble, Final Rule to Implement the 8-hour Ozone National Ambient Air Quality 

Standard” 70 FR 71612; November 29, 2005.

11. “Reasonably Available Control Technology (RACT) Demonstration for Ozone State 

 

21 SJVUAPCD Rule 4570, Confined Animal Facilities, Table 4.1.(B), adopted October 21, 2010.
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Implementation Plans (SIP)” SJVUAPCD, April 16, 2009 (pages 4-99 to 4-169).

12. Letter from William T. Harnett to Regional Air Division Directors, “RACT Qs & As –

Reasonable Available Control Technology (RACT): Questions and Answers,” EPA, May 

18, 2006.

13. SJVUAPCD Rule 4570, Confined Animal Facilities, adopted October 21, 2010. 

14. “Final Staff Report for Revised Proposed Amendments to Rule 4570 - Confined Animal 

Facilities,” SJVUAPCD, October 21, 2010, and its appendices