United States Environmental Protection Agency

Region IX

75 Hawthorne Street

San Francisco, CA 94105-3901

October 06, 2010

Transmittal of EPA Rule Review Comments

To: Koshoua Thao, San Joaquin Valley Air Pollution Control District

koshoua.thao@valleyair.org

Mike Guzzetta, California Air Resources Board

mguzzett@arb.ca.gov

From: Andrew Steckel, Rulemaking Office Chief

steckel.andrew@epa.gov

Re: SJVUAPCD Rule 4566, Composting and Related Operations, September 22, 2010 draft

We are providing comments based on our preliminary review of the draft rule identified above. Please 

direct any questions to me at (415) 947-4115.

General

1. The staff report should explain the basis for the various thresholds and limits in the rule such as, for 

example, three days and six inches of compost cover in section 5.1.1.2, three inches moist compost in 

section 5.2.2.1, and six inches cover at the pile peak in section 5.2.3.1. 

2. The draft staff report and attachments rely on several studies in designing Rule 4566, but omits 

important information, such as temperature, C:N ratio, moisture content and feedstock details of the 

studied compost piles. Please add this information to better support the rule design. More detail is 

particularly important for the heavily-cited Tulare County Composting study by San Diego State University.

3. We recommend that the environmental impact analysis cited in Section VIII of the draft staff report 

include consideration of: (1) groundwater impacts where sprinkler irrigation is used; and (2) NOx 

emissions from equipment used to control VOC.

4. In response to our previous request for a demonstration that this rule implements RACT, page 2 in 

Appendix A of the draft staff report refers to Appendix C. However, we see no discussion of RACT in 

Appendix C. 

Specific Provisions

1.0 - While we recognize that Rule 4566 is primarily designed to control VOC, some provisions may also 

help address other air pollution issues in the Valley. Please consider mentioning particulate matter and 

ammonia emission reductions as part of the purpose statement.

3.1.1 & 3.22.1 - Please remove or better justify the 22 and 40-day limits in the definitions of active and 

curing composting. California, for example, defines active compost only by temperature generation, CO2

release rate and Oxygen uptake. See CCR Title 14 Section 17852(a)(1). 

3.19 - The definition of composting includes anaerobic processes, but the rule otherwise targets aerobic 
composting. Please clarify how SJVUAPCD intends to address anaerobic processes within this rule or

elsewhere. 

3.9, 5.1.1.3, 5.1.2.3, 5.2.2.2, 5.2.3.2 and elsewhere allow the APCO to approve equivalent alternate 

mitigation measures as described in paragraph 6.3. National policy discourages SIP provisions that allow 

APCO discretion to independently modify SIP requirements (e.g., the Little Bluebook and 52 FR 45109, 

11/24/87.) However, some discretion may be appropriate for activities, like composting, with little 

regulatory history. Such discretion should be limited by defining procedures that the APCO must use in 

exercising discretion. Paragraph 6.3 and elsewhere include reasonable limitations given composting's 

limited regulatory history. Nonetheless, this discretion should be further limited in the future as 

SJVUAPCD and other agencies gain experience with the industry. 

3.52, 6.2, 6.2.6 and elsewhere reference test methods developed by the Composting Council Research 

and Education Foundation and allow the APCO to approve alternative methods and procedures. National 

policy encourages use of EPA-approved test methods in SIP rules and discourages SIP provisions that 

allow APCO discretion to independently modify SIP requirements (see, e.g., the Little Bluebook and 52 FR 

45109, 11/24/87.) However, some deviation from this policy may be appropriate for activities, like 

composting, with little regulatory history and without EPA-approved methods for all relevant parameters. 

Testing and other procedures should be further standardized in Rule 4566 in the future as SJVUAPCD 

and other agencies gain experience with the industry. 

4.1 and 4.3 - Please consider adding size thresholds to these exemptions. It may be appropriate to apply 

some or all of Rule 4566 requirements to facilities addressed here that are very large. 

4.2 could be read to mean, for example, that facilities both composting greenwaste and stockpiling wood 

chips are exempt from all rule requirements. One way to address this would be to revise 4.2 to read, 

"Facilities that only stockpile organic materials from the following operations are exempt from all 

requirements of this rule."

5.1 - Draft South Coast Air Quality Management District (SCAQMD) Rule 1133.3(d)(1) includes additional 

requirements for stockpiling. Please consider adding similar requirements for stockpiling foodwaste 

(1133.3(d)(1)(B) and (C)) to reduce VOC, odor and nuisance, as well as the other draft SCAQMD 

requirements regarding stockpile height (1133.3(d)(1)(D)), temperature (1133.3(d)(1)(E) and (F)), and 

recordkeeping (1133.3(d)(1)(G)).

5.1.1.1 & 5.1.1.2 - These paragraphs could be read to mean that stockpiles can remain uncovered for 

unlimited days, as long as they are eventually covered by six inches of finished compost. For clarity, we 

suggest revising these sections to: "Process or use the organic material within three (3) days of receipt; 

and or cover each of the stockpiles, that is not processed within three (3) days of receipt with at least six 

(6) inches of finished compost within three (3) days of receipt; or."

5.1.2.1 & 5.1.2.2 should also be revised as described in the previous comment regarding 5.1.1.1 and 

5.1.1.2.

5.2.1 - Draft SCAQMD Rule 1133.3(d)(2) and (3) include additional general requirements for compost 

facilities. Please consider similarly requiring turned windrows (1133.3(d)(2)(A) and (3)(B)), 

scraping/sweeping mixing and other areas (1133.3(d)(2)(B)), carbon/nitrogen ratios when composting 

foodwaste (1133.3(d)(3)(D)), and a temperature range (1133.3(d)(3)(E)).

5.2.1.2 - Please consider revising the draft moisture content limit of 40-70% consistent with the 50-60% 

limit in draft SCAQMD Rule 1133.3(d)(3)(F).

5.2.1.3 requires weekly testing unless the APCO establishes a different frequency. Draft SCAQMD Rule 

1133.3(d)(3)(H) requires daily testing and does not allow alternate frequencies. Please consider more 

frequent testing consistent with draft Rule 1133.3 and, if alternates are truly necessary, clarify that the 

APCO cannot establish an alternate frequency beyond a specified appropriate outer bound.
5.2.1.4 - Please specify that records should be kept of parameters found to be outside applicable limits 

and all corrective action.

5.2.2 requires facilities with 10,000 - 25,000 tons/year thoughput to water compost piles within three hours 

before turning and until three inches in depth is wet. SJVUAPCD projects significant emissions from a 

10,000 ton/year facility, and draft SCAQMD 1133.3 does not set a similar 10,000 ton or other minimum 

size threshold. Please consider: (1) applying Rule 4566 requirements to smaller facilities; (2) establishing 

a minimum frequency for pile turning (e.g., once/X-days); and (3) editorial revisions to clarify that this 

requirement should not lead to excess moisture in the pile causing anaerobic conditions. Please also 

clarify in the staff report how this measure reduces emissions.

5.2.3 requires facilities above 25,000 ton/year to cover piles within three hours of turning with six inches of 

finished compost at the peak. Please analyze: (1) applying it to smaller facilities similar to draft SCAQMD 

1133.3(d)(3)(C); (2) requiring cover within one hour of turning instead of three hours similar to 

1133(d)(3)(C); (3) establishing a minimum frequency for pile turning (e.g., once/X-days); and (4) 

establishing a second level of minimum cover near the base of the pile (e.g., X-inches of cover Y-feet from 

the base) in addition to the requirement of six inches at the peak. We appreciate that it is difficult to 

evenly cover piles and note that appendix C page 4 of the draft staff report projects that six inches at the 

peak equates to two inches at the base. However: (1) there is no assurance that six inches at the peak 

leads to two inches at the base; (2) there's no demonstration that two inches at the base effectively 

reduces emissions, and (3) a requirement near the base will be easier to monitor than six inches at the 

peak. 

Section 5.3 - Please analyze more aggressive requirements, particularly for large operations that process 

foodwaste which can generate high VOC, ammonia and odors. Draft SCAQMD 1133.3(d)(4), for example, 

requires 80% control using aeration or other systems for greenwaste operations with more than 25% 

foodwaste.

7.1.3, 7.1.4 & 7.1.5 use the undefined term "windrow." Please define this in section 3.