SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Significant Comments and District Responses October 21, 2010 

APPENDIX A 

SIGNIFICANT COMMENTS AND DISTRICT RESPONSES TO 

REVISED PROPOSED AMENDMENTS TO RULE 4570 

(CONFINED ANIMAL FACILITIES) 

October 21, 2010 

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Appendix A: Significant Comments and District Responses October 21, 2010 

APPENDIX A 

SIGNIFICANT COMMENTS AND DISTRICT RESPONSES FOR 

OCTOBER 2010 REVISED PROPOSED RULE 

US EPA REGION IX STAFF COMMENTS 

1. Comment: We strongly support the District's efforts to remove less effective 

compliance options in the proposed rule revisions. We are still reviewing the 

extensive additional analysis that the District released in late September with 

respect to the Clean Air Act requirement for all economically and technically 

feasible controls. However, it is clear that the rule and technical support has been 

substantially improved. Thank you again for the extensive time and effort that you 

and many others at the District have dedicated to this effort. 

Response: Comment noted. 

ARB STAFF COMMENTS 

No comments were received. 

STAKEHOLDER COMMENTS

Stakeholders submitting written comments: 

Dairy Cares (DC) 

Center on Race, Poverty and the Environment (CRPE) 

2. Comment: Even if the economic picture were better, Proposed Rule 4570 

would add significant operating costs to dairies that would be cause for concern. 

Additional costs – especially when not borne by our competitors outside 

California – hamper the ability of our state’s dairies to compete in national and 

global markets. We have examined the District’s economic analysis and find it 

fundamentally sound. These increased costs come at a time when the dairy 

industry has not fully absorbed the costs of other significant environmental 

regulations adopted recently. In summary, California dairies operate in a more 

regulated and expensive environment than their competitors in other states. 

Although Rule 4570 will significantly reduce emissions from dairies, these 

reductions are only expected to improve air quality very slightly. That is because 

the VOC emissions from dairies have only a limited role in producing valley 

ozone. In other words, while Rule 4570 will have a definite and visible impact on 

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Appendix A: Significant Comments and District Responses October 21, 2010 

the business costs of dairy families, it will have a barely discernible impact on air 

quality and only in a few places in the valley and only on a few days a year. (DC) 

Response: District staff has worked closely with the dairy industry and other 

stakeholders to balance the impact of emission reductions against the economic 

impact to affected operators. 

3. Comment: Some critics of the District’s approach have charged that the 

proposed rule only encodes practices that are reflective of the status quo in the 

industry. Based on a review of permitted Large Confined Animal Facilities 

(LCAFs) already under the District’s purview, Appendix C specifically identifies 

several practices that are used on fewer than half of LCAFs, and in at least one 

case, a practice that is used on fewer than one in ten LCAFs. Further, while no 

comprehensive survey of air quality practices utilized by smaller dairies exists, it 

is reasonable to assume that many of these much smaller, often older, resourcelimited facilities likely did not voluntarily take on many of the air quality mitigation 

practices utilized by their larger neighbors. As such, the rule can be expected to 

provide substantial emission reductions from dairies in a manner that is about as 

cost-effective as can reasonably be expected. Though the rule is costly and will 

have only small benefits to regional ozone levels, the District has made a good 

faith effort to consider costs and reject technically or economically infeasible 

proposals. (DC) 

Response: District staff’s emission reduction analysis and cost analysis 

included a query of the permits database to assess what fraction of current 

facilities have implemented a given mitigation measure. The fraction was applied 

to the costs and estimated emission reductions to more accurately reflect current 

dairy practices. 

4. Comment: While the proposed rule is based on a combination of improved data 

and reasonable assumptions, more information is still needed to assess the realworld effects of the various parts of the proposed rule. It should be recognized 

that Rule 4570 was designed to be applicable in general to dairies. Once applied 

to real-world dairies, unforeseen situations will arise that will require flexibility 

during implementation, especially at atypical dairy operations. This flexibility is 

needed in ongoing interactions with District staff and individual dairy operators, 

but also may be needed in the future as we learn more about the effectiveness of 

the various measures in the rule; future revisions to the rule may be needed. 

(DC) 

Response: The District remains committed to implementing the latest research 

in a practical way at dairies and other CAFs and will work with operators as 

issues may arise. The rule does allow for an alternative measure to be 

substituted for a measure if approved by the District. 

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Appendix A: Significant Comments and District Responses October 21, 2010 

In light of the fact that Rule 4570 will also now apply to more operations and that 

those operations will be smaller than those currently regulated, the District is 

committed to providing multiple resources and tools to minimize costs and 

administrative burden associated with the implementation of this rule. District 

staff plans to review required records to minimize paperwork burden and provide 

outreach to the medium-sized CAFs throughout the Valley. 

5. Comment: Overall the District clearly identified numerous measures that are 

technically and economically feasible. Not a single measure that was found by 

District staff to be technically and economically feasible was left out of the rule. 

Every important management unit of the dairy was examined and the mitigation 

practices extend into all of these areas and virtually all facets of the dairy 

operation, with perhaps only the dairy employee break room and the 

bookkeeping office being the only parts of the dairy facility that are unregulated 

for their air emissions. 

Because not all potential mitigation measures have been tested on real dairies, 

the District wisely focused its emissions reduction strategy on identifying 

measures that are already in use on at least some dairies. This approach 

ensures that while the proposed measures have not been “road-tested” at all 

dairies, they have been used at least enough dairies to ensure their adoption 

should not cause significant, widespread industry problems. (DC) 

Response: Comment noted. 

6. Comment: Few real “options” exist in the Rule. Where options exist, it is 

precisely because the District has made a finding – correctly – that the mitigation 

practice in question is not economically and technically feasible for all dairies. It’s 

often not practical (and sometime not even possible) to accomplish all options. 

One must do one measure exclusive of the others. In some cases a choice is 

provided because it is economically or technically feasible for some but not all 

dairies. By combining practices that are not – when considered singularly – 

technically or economically feasible – into a limited list of options, their overall 

chances of being technically and economically feasible increases greatly. The 

District’s approach of adding such options to a rule that also includes many 

obligatory mitigation measures has the overall effect of producing additional 

emissions reductions. Without the “menu” approach, some of these measures 

that have been included in the rule would have to be eliminated because they 

would not be feasible for most dairies. (DC) 

Response: Comment noted. 

7. Comment: Dairy Cares supports adoption of Rule 4570 as proposed. Although 

the Rule is imperfect and relies on limited data about emissions and emissions 

reductions, and although it will impose significant costs on San Joaquin Valley 

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Appendix A: Significant Comments and District Responses October 21, 2010 

dairies, and although it will result only in very small reductions in ambient ozone 

levels, we believe the District has nevertheless made a good faith and diligent 

effort to formulate the rule appropriately, based on the best available scientific 

research, socioeconomic analysis and known data on technical feasibility issues. 

(DC) 

Response: Comment noted. 

8. Comment: In its comment letters to the District, EPA stated that every measure 

that is economically and technically feasible must be made mandatory to 

demonstrate that the Rule meets RACT. While the current proposed Rule 

includes more mandatory measures than the previous draft, many of those 

measures are already practiced by the regulated entities and the Rule still follows 

a menu approach. The Rule continues to violate RACT because it permits 

operators to bypass emission reduction measures that are economically and 

technologically feasible in favor of other measures that achieve less, or zero, 

reductions. The menu approach continues to allow operators to pick and choose 

from a group of measures that should be implemented together to realize a 

comprehensive emission reduction strategy. (CRPE) 

Response: Rule 4570 affects a wide variety of operations with differing sizes 

and management practices. Based on the many variations between operators 

subject to Rule 4570, a somewhat flexible approach is necessary since not all 

dairies can implement each mitigation measure. The mitigation measures were 

evaluated to determine which measures would achieve the most reductions, 

namely in feed, silage and housing, and if each measure would be 

technologically and economically feasible to require every operator to implement. 

The mitigation measures in the proposed rule have been amended to provide 

more requirements, as well as make many of the measures mandatory. All 

measures were also evaluated for technological and economic feasibility (see 

Appendices C and E). A RACT analysis was prepared as a separate document 

and demonstrates Rule 5470 satisfies RACT. Furthermore, a menu approach 

has already been upheld as BACM for agricultural sources by the 9th Circuit and 

BACM is presumably more stringent than RACT (Latino Issues Forum v. 

U.S.E.P.A., 558 F.3d 936, 9th Cir. 2009). 

9. Comment: The revised Rule 4570 violates RACT because it fails to fully 

analyze the cost-effectiveness of enclosed freestall barns that vent emissions 

through biofiltration systems. Given that this technology holds great potential for 

VOC reductions, the cost effectiveness analysis should be full and accurate. The 

current Staff Report includes increased milk production, using the lowest price, 

but does not account for increased birthing rates. Milk prices are currently rising 

and staff should have calculated potential income using the full spectrum of 

current prices. The District should account for increased birthing rates in its 

calculations of cost effectiveness. 

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Appendix A: Significant Comments and District Responses October 21, 2010 

It is puzzling how previous District calculations on the cost effectiveness of barnto-biofilter technology fell below the $17,500/ton of VOC emissions reduced 

threshold in previous analyses, and now it is estimated between $205,098 - 

$4,172,332/ton of VOC reduced. It is also disheartening to see that the option to 

enclose barns and parlors has been eliminated from the Phase II mitigation 

measures. (CRPE) 

Response: The District performed a detailed analysis for this measure using the 

latest information, which is included in Appendix E of the Final Draft Staff Report. 

Previous analyses showing lower cost effectiveness for this measure were used 

to determine BACT. Therefore, District staff looked only at the cost of certain 

aspects and concluded the measure was too costly once the cost effectiveness 

reached a certain point. The cost effectiveness determined in Appendix E is more 

accurate and appropriate because it takes a comprehensive approach, including 

all factors. This measure has been determined to not be economically feasible for 

Valley operations and therefore it has been removed as an option in the Rule. 

The District was not able to find a strong basis demonstrating that there would be 

an increase in birthing rates with such a measure. Even with an increase in 

birthing rates, the additional calves would need to be sold as they would not be 

allowed to remain onsite unless changes in capacity and permit limitations were 

undertaken. The profit generated from the sale of additional calves would be 

insignificant relative to the total cost of implementing this measure. 

10. Comment: Dairies will be able to comply with the mitigation measures without 

making any changes whatsoever. This will result in little to no VOC reductions 

from these measures. While the District contends that not all dairies are currently 

complying, there is no basis for differentiating where reductions are real and 

where they merely appear on paper. Because the San Joaquin Valley is an 

extreme non-attainment area for ozone, federal law requires RACT and state law 

requires that the Air District use best available retrofit control technology 

(BARCT) to achieve actual reductions in emissions. Emission controls that 

merely codify the status quo fall short of these standards. (CRPE) 

Response: Prior to Rule 4570, dairies managed their facilities based on 

management practices that the dairy was accustomed to and based on costs 

associated with each management technique. Changes in cost would allow the 

dairy operator to shift management methods that may have not always been in 

favor of air emissions. However, Rule 4570, adopted in 2006, for the first time, 

required dairy operators to invest in management practices specifically to reduce 

emissions at their dairies. These changes not only required these measures to 

become permanent regardless of external factors but were also enforceable. 

Dairies simply could not change those measures without replacing a measure 

with a similar or better measure. Due to the investment made from the initial 

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Appendix A: Significant Comments and District Responses October 21, 2010 

Rule 4570, more mitigation measures have become common on dairies, 

specifically the larger dairies subject to Rule 4570. However, a District query of 

the mitigation measures showed that not all of the dairies had selected each 

mitigation measure. In fact some of the mitigation measures were only being 

implemented by a very small percentage of dairies. The proposed rule would 

also incorporate additional mitigation measures reflecting new research and 

mandate measures in categories with high emissions, such as silage, feed, and 

housing. Therefore, the mitigation measures being required by Rule 4570 have 

and will continue to result in real emissions reductions. 

11. Comment: The assumption that a six-inch reduction in the placement of feed 

would reduce the surface area of the feed fails to account for the movement of 

the pile. Dairy cows are constantly moving the feed around with their snouts as 

they eat, continuously exposing the TMR to the air and releasing VOCs. There is 

no monitoring or infallible procedure by which the feed will remain within 3 feet of 

the stanchion or ensure that the public or EPA has access to such information in 

order to enforce the requirement against violators. Given that this measure 

appears to be the most important VOC control measure in the Valley, the District 

needs to make major changes to ensure that such measure is both enforceable 

and does not double count reductions. (CRPE) 

Response: This measure reduces emissions by reducing the surface area of 

the feed placed in the feed lanes. Reducing the surface area would result in a 

decrease in overall VOC emissions. Studies have shown that the VOC flux 

rapidly declines after placement of feed. Although dairy cows may push some of 

the feed back from stanchions, the proposed rule will require that the feed be 

pushed up soon after it has been placed to reduce the area when the flux rate is 

high. In addition, pushing the feed near the fence line places the feed within 

reach of the cows so it can be consumed rather than remaining in the feed lane 

where it can continue to emit VOCs. 

12. Comment: The Board should not accept the massive assumption, without a 

scientific basis, that the various measures each achieve a 10% reduction. Most 

of the measures for dairies are assumed to have a 10% reduction. The District 

should have to clearly show how Rule 4570’s control measures achieve the 

expected reductions. (CRPE) 

Response: There has been a great deal of emissions research conducted over 

the last decade on dairies alone, with millions of dollars spent on this research. 

The latest research has significantly improved the understanding of emissions 

from all the sources at dairies which has also resulted in a better understanding 

of the biological factors and conditions that create VOC emissions from the 

various sources. This understanding has allowed the District to develop 

mitigation measures by changing the biological process or condition of the 

sources to reduce emissions. These mitigation measures are expected to 

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Appendix A: Significant Comments and District Responses October 21, 2010 

reduce emissions by well over 10%, however, the District has taken a 

conservative approach of estimating the reductions from the rule and uses the 

lower end of the control effectiveness range cited in the studies. While this may 

underestimate the actual reductions, the 10% control efficiency better accounts 

for normal variations in the organic processes at CAFs. Therefore, until more 

definitive research data becomes available, the District will continue to 

conservatively estimate the reductions from the rule. Where research indicated 

a higher control efficiency was appropriate, the information was cited for that 

finding. 

SIGNIFICANT GOVERNING BOARD MEMBER COMMENTS RECEIVED 

AT THE OCTOBER 21, 2010 PUBLIC HEARING 

13. Comment: We commend stakeholders and District staff for all of the time and 

effort that went into this rule. Though the rule will be incredibly expensive to 

implement, it will have long term benefits. It may be a real problem for medium 

size dairies to implement. How will the District monitor the cost and effects 

throughout implementation? 

Response: District staff has planned many outreach sessions in October and 

November of 2010 as well as continuing dialog with all industry representatives 

and individual operators through the Small Business Assistance program. 

SIGNIFICANT STAKEHOLDER COMMENTS RECEIVED AT THE 

OCTOBER 21, 2010 PUBLIC HEARING 

14. Comment: By adopting this rule, the District will miss an opportunity to shift 

from corn-based feed to grass-fed and open range dairies. This type of shift 

would be more sustainable and result in fewer emissions. 

Response: District staff has not found any studies showing air quality benefits 

for shifting from corn-based to grass-fed only. In addition, the impact on milk 

production is not known. It could result in lower milk production and therefore a 

need to increase the number of cows to maintain the same amount of milk 

production. 

15. Comment: Dairies want to do their part to clean up the air but the menu is 

needed due to the variability from dairy to dairy. We request flexibility to work 

with staff during the permitting process to address and facility-specific issues. 

Response: See Comment 4. 

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Appendix A: Significant Comments and District Responses October 21, 2010 

SIGNIFICANT COMMENTS AND DISTRICT RESPONSES FOR 

JUNE 2010 REVISED PROPOSED RULE 

US EPA REGION IX STAFF COMMENTS 

16. Comment: The District needs to demonstrate that Rule 4570 implements RACT 

by requiring those measures that are economically and technically feasible. 

Where individual measures or sets of measures are feasible, please make them 

mandatory. For any measures that remain as optional after the District's 

changes, please provide a detailed analysis of economic and technical feasibility. 

In general, EPA believes that all measures determined to be economically and 

technically feasible should be mandatory elements. Justifications related to 

economic feasibility should be supported by quantitative analysis. 

The District agreed to provide a more expansive feasibility analysis of biofilters 

that considers dairies larger than 500 head. The District should complete this 

analysis so EPA and other stakeholders can review it and provide comments. 

Response: Please refer to the Incremental Analysis in Appendix C for a 

quantitative analysis of additional measures. The biofilter analysis is available in 

Appendix E of the Staff Report. 

17. Comment: Large dairy CAFs are required to feed according to National 

Research Council (NRC) guidelines, which are said to reduce starch in manure 

which lowers VOC emissions. However, the NRC guidelines are extremely 

complex and it is unclear which sections reduce starch. To clarify, please add a 

reference to the section in the NRC guidelines that reduces starch. Also, please 

further describe the relationship between reduced starch in manure and VOC 

emissions in the staff report. 

Response: The NRC guidelines do not address starch specifically, since it is not 

a nutrient, but feeding according to the guidelines will guarantee excess starch 

will not be excreted. Several studies have shown excess starch can leads to 

increased volatile fatty acids and VOC emissions. The Staff Report has been 

revised to explain this connection and to cite these studies. 

18. Comment: Several measures are designed to reduce emissions by removing 

uneaten feed from various areas within one to 14 days. However, these 

measures may be relatively ineffective because VOC emissions from silage are 

mostly emitted within 12 hours of removal from the silage pile. 

Other measures are intended to reduce VOC emissions by minimizing spoilage 

in feed wet by rain. These measures may also be ineffective in areas that get 

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Appendix A: Significant Comments and District Responses October 21, 2010 

little rain. In light of the large estimated emissions from dairy feed, please 

consider whether the mitigation measures can be revised to further reduce VOC 

emissions by revising or eliminating potentially low-effective measures. 

Response: The requirements have either been revised or removed from the 

rule. See the Final Draft Staff Report, beginning in Section X.F., for detailed 

explanations. 

19. Comment: Please consider whether it would be feasible to require partially 

enclosed feedbunks to reduce VOC emission losses from total mixed rations. 

Response: This technology does not exist at this time and may be infeasible for 

most facilities due to the nature of feed management on dairies. 

20. Comment: Please define the following terms "high moisture corn," "steamflaked corn," "steam-flaked cereal grains," "dry rolled corn," "hard kernel," and 

"soft kernel" in the rule. 

Response: Appropriate definitions have been added under Section 3.0 of the 

rule. The terms “soft kernel” and “hard kernel” have been removed entirely from 

the rule because at the level of plant maturity when corn is harvested for silage, 

the difference between hard kernel and soft kernel corn is negligible and, 

therefore, these terms do not need to be included or defined in the rule. 

21. Comment: Please evaluate whether having silage piles that can be completely 

driven over with a tractor or having silage piles with side walls are economically 

and technically feasible and could be added as required or additional mitigation 

measures will help improve pile compaction. 

Response: The proposed rule includes the option for direct measurement of the 

density of silage piles and practices that will achieve the required density. 

District believes that the majority of the surface of silage piles will be driven over 

to some extent to adequately compact and preserve the silage. The District does 

not have sufficient information to determine that silage piles with side walls have 

significantly higher density than piles without side walls. In addition, space 

constraints at existing facilities may make it difficult to construct drive-over silage 

piles or walled silage structures; therefore, these requirements were not included 

in the proposed rule. If more information becomes available, these measures 

may be re-evaluated under future rule amendments. 

While these particular pile types are not common in the Valley, the Phase II 

silage section does not prohibit their use. The rule instead focuses on pile 

properties that retain nutrients and minimize conditions that enhance VOC 

emissions. In this way, the rule does not specify any particular pile configuration, 

allowing for operational flexibility while minimizing VOC emissions. 

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Appendix A: Significant Comments and District Responses October 21, 2010 

22. Comment: Dairies electing silage Mitigation Measure 1 must cover silage piles 

with a plastic tarp. Please consider also requiring that the tarp be weighed down 

to ensure close contact with the pile, thus minimizing silage exposure to air. 

Response: Weighing down the silage cover is standard practice and is in the 

best interest of the owner to reduce spoilage. However, the ways to weigh down 

the cover can vary greatly, so the language has not been specified in the rule. 

23. Comment: The dairy silage mitigation measures require that corn silage be 

harvested at 65% moisture, which we believe means that dry matter must be 

35%. However, the table under this item currently allows 34-37% dry matter 

content for processed corn. For clarity, please either adjust the percent moisture 

at harvest or the range of dry matter content for processed corn. 

Response: The percent dry matter has been adjusted to be consistent with the 

preceding language. 

24. Comment: Because of the large emissions estimated from silage, please 

consider limiting selection of limiting total exposed silage faces for multiple 

uncovered silage piles to facilities above a certain geographic size. Please also 

consider whether editorial revisions are appropriate to prevent a source from 

claiming compliance while having one silage pile with 4,300 square feet exposed 

surface area and a second fully closed pile. 

Response: The District evaluated whether size of piles should be established 

based on geographic sizes of the facility and has determined that there is no 

direct relationship between the size of the silage pile and the physical area a 

dairy occupies. Land availability and CAF design plays a critical role in 

determining the size of a silage pile. Where CAF operators have land area 

limitations will tend to have taller piles (with the most likely consequence of 

having a larger open face) when compared to operators of dairies who have 

more land for silage storage and can build longer or wider piles to store the same 

amount of silage. 

District staff has revised the wording of the mitigation measure to make clear that 

it is the total uncovered face that is counted. 

25. Comment: Please consider if it is feasible to revise dairy silage Mitigation 

Measure 2 to require covering the open face of Ag-bags when not removing 

silage. Please also consider whether it is feasible to require inspecting Ag-bags 

periodically for holes, with appropriate action taken to patch them. 

Response: The size of these Ag-bags is significantly smaller compared to 

standard silage piles. Unlike the tarps used on standard silage piles, the Ag-

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Appendix A: Significant Comments and District Responses October 21, 2010 

bags are not reusable. These bags are torn as needed when removing silage. 

Therefore, it is not practical to require that the operator re-cover the open face of 

the bag between the times when silage is being removed. The costs for Ag-bags 

are already significant, requiring additional measures may prevent facilities from 

installing these bags.

26. Comment: To improve clarity, please specify how frequently sources need to 

vacuum manure if selecting dairy corral Mitigation Measure 9. 

Response: This measure has been removed from this section because it applies 

to land application, not to corrals. The land application section is the more 

appropriate location for this mitigation measure. 

27. Comment: The swine, layer, and the broiler/turkey measures have requirements 

for removing or disposing of feed during time frames that range from 48 hours to 

14 days. It is our understanding that poultry and swine feed do not contain 

fermented components like silage that could be a source of VOC emissions. 

Please justify how removing or disposing of feed reduce emissions for poultry 

and swine facilities. 

Response: The feeds used for these types of facilities are predominantly grainbased. The overall emissions from grains are considered to be negligible based 

on information provided by a report by Dr. Mitloehener. All feed measures 

related to dry grains have been removed from this section of the rule. Further 

information is included in Sections X.I and X.J of the Final Draft Staff Report. 

28. Comment: The beef feedlot and other cattle sections all have measures for 

removing or disposing of feed during time frames that range from 48 hours to 14 

days. We understand that feed for feedlots and other cattle may contain silage. 

Please assess whether the feedlot or other cattle feed could be a source of VOC 

emissions. If the District decides to keep these measures for the beef and cattle 

sections, please consider adjusting the timeframes in these measures to 

correspond with recent research which suggests VOC emissions from silage are 

mostly emitted within 12 hours of removal from the silage pile. 

Response: There may be some “other cattle” facilities that feed silage, for that 

reason, a silage mitigation measure category has been included to ensure 

reductions from silage are achieved. However, the majority of facilities, 

specifically feedlots will feed cattle largely with a grain based feed. As discussed 

in more detail in the staff report, based on information provided by Dr. Mitloehner 

(see letter in Appendix J), grain base emissions will be assumed to have 

negligible emissions. Therefore, all measures related to grain-based feed have 

been removed from this section of the rule. 

 

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Appendix A: Significant Comments and District Responses October 21, 2010 

29. Comment: The feedlot, other cattle, layer, and the broiler sections allow sources 

to comply by feeding animals according to National Research Council (NRC) 

guidelines. The NRC guidelines that apply to different livestock types are 

extremely complex and we are unclear which sections of the guidelines lead to 

reduced VOC emissions. Please consider specifying these sections in the rule, 

or explain why it is not appropriate to do so. Please further describe the 

relationship between following the NRC guidelines and reducing VOC emissions 

in the staff report. 

Response: The NRC guidelines are geared to supply the exact blend and 

quantity of nutrients needed by the animals with the minimum being excreted and 

lost to the environment. Therefore, referencing certain sections would not be 

beneficial as the complete guidelines are needed. The relationship between NRC 

guidelines and VOC reduction is described in Section X. of the Staff Report. 

30. Comment: Several measures in the rule refer to specifications or definitions in 

NRCS standards. Please consider including the date of the NRCS standard in 

the rule language. It is our understanding that these standards are revised over 

time, and neither EPA nor the District provides input for the revision of these 

standards. 

Response: At this time, the reference dates will not be added. The standards 

are revised over time and it would be conflicting for the District to require a 

standard that has been outdated. Changing the rule references as the standards 

are revised would require the rule to be reopened each time the standard is 

revised. It is expected that facilities will comply with the most recent standard. 

District staff may review the standards as they are changed to ensure no conflicts 

with the requirements of this rule or detriment to air quality. 

31. Comment: For other cattle, the draft rule requires that sources select seven 

measures from the housing options that combine measures for freestalls and 

corrals. Dairies have separate sections for freestalls and corrals that require 

large CAFs to select a total of nine measures. Please analyze whether it is 

appropriate to have separate freestall and corral sections for other cattle, and to 

require a similar number of measures as dairies from these sections. 

Response: The housing section for other cattle has been separated into two 

separate sections covering freestalls and corrals. Three measures and six 

measures are now required in the new freestalls and corrals sections, 

respectively, making it more consistent with the dairy sections. 

32. Comment: Several options in the feedlot housing and the other cattle housing 

section require sources to ensure that manure in the corrals does not exceed 12 

inches. Please analyze whether it is appropriate to require a lower corral manure 

depth. 

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Appendix A: Significant Comments and District Responses October 21, 2010 

Response: The corral manure depth for cattle has already been reduced from 

18 inches down to 12 inches, which is a 33% reduction is manure depth. Based 

on discussions with industry, decreasing the depth below 12 inches would 

require significantly more frequent cleaning and cause greater disruption to the 

animals which are not accustomed to such equipment operations. The District 

has not found any evidence that would support lowering this requirement to a 

lower depth.

33. Comment: Specific measures in the beef feedlot housing and the other cattle 

housing sections require sources to inspect water pipes and troughs and repair 

leaks at least once every 14 days. Please provide analysis for why inspecting 

and repairing pipes and troughs at this interval reduce VOC emissions. 

Response: See Staff Report Sections X.G and X.H for details. The District 

believes that this is a proper frequency to control potential leaks and to not cause 

moist conditions in open corrals. In open corrals, moist conditions lead to 

anaerobic decomposition of manure. Emissions of gaseous compounds can be 

reduced by faster drying of manure and minimization of moisture. Minimizing the 

moisture in the manure reduces the moisture needed by the microbes that 

decompose the manure to form VOC. 

34. Comment: Please remove the option from the beef feedlot housing section that 

requires feedlots to use a dry manure handling system or explain why this 

measure reduces VOC emissions. It is our understanding that affected feedlots 

already overwhelmingly use dry systems. 

Response: This measure has been removed. Further information is included in 

the Section X.G of the Staff Report. 

35. Comment: Measures in the layer and the broiler/turkey sections require sources 

to use a dry housing cleaning method except when a wet cleaning method is 

required for animal health or biosecurity issues. Please clarify how sources can 

obtain this exemption by referencing Section 5.4, temporary suspension of 

mitigation measures, or inserting other rule language. 

Response: The appropriate reference has been made. See Section X.J of the 

staff report for details. 

36. Comment: A mitigation measure in the broiler/turkey section requires that 

sources use a litter/manure drying system such as a flat bed drying system. If 

this system requires belts under the animals, it may not be applicable to 

broiler/turkey houses where animals are directly on the ground. Please consider 

whether this measure applies to broiler/turkey houses 

 A-16 Final Staff Report with Appendices For 

Revised Proposed Amendments to Rule 4570 
SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Significant Comments and District Responses October 21, 2010 

Response: This measure has been removed from the broiler/duck/turkey section 

because it is not applicable to broiler houses. 

37. Comment: Please explain in the staff report why certain mitigation measures 

reduce VOC emissions, and provide any supporting references. 

Response: The explanations have been included in the staff report Section X. 

for each CAF type. 

38. Comment: Based on currently available information, manure may be one of the 

largest sources of VOC emissions at poultry facilities. Please explain the basis 

for allowing litter removal from poultry facilities within 72 hours of removal from 

housing. 

Response: The District has re-examined the information that is currently 

available for VOC emissions from California poultry operations and determined 

that litter at these facilities is not a significant source of VOC emissions. 

Additionally, it is necessary to allow facilities sufficient time to remove the litter. 

Facilities that remove litter entirely from the facility intend to remove it as soon as 

the litter is removed from the housing. However, there are several factors that 

may prevent the litter from being removed earlier than 72 hours. Due to possible 

planning constraints, operators may not be able to ensure litter is removed 

immediately. Depending on how much litter is removed, this process can take 

quite some time. In addition, there are times when a truck is delayed or breaks 

down. In those cases, other arrangements need to be made immediately to 

ensure that the litter is removed in a timely fashion. Due to these factors, 72 

hours have been allowed for the litter removal. 

ARB STAFF COMMENTS 

No comments were received. 

 A-17 Final Staff Report with Appendices For 

Revised Proposed Amendments to Rule 4570 
SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Significant Comments and District Responses October 21, 2010 

STAKEHOLDER COMMENTS RECEIVED AT THE JUNE 17, 2010 

PUBLIC HEARING 

Center on Race, Poverty and the Environment (CRPE) 

39. Comment: Emerging science has pointed to huge sources of VOC pollution 

from Valley dairies that have not been regulated. The proposed amendments fail 

to adequately respond to this new science. We are encouraged by the 

continuation of the hearing in response to EPA’s request for more time to study 

and respond to the science. 

Response: The District committed to adopting amendments to Rule 4570 in the 

2007 Ozone Plan in order to reduce VOC emissions which form ozone. Multiple 

new requirements were added to Rule 4570 to address new data citing silage, 

TMR, and corrals as the largest sources of emissions on a dairy and ensure 

emission reductions from them. The amendments to Rule 4570 will exceed the 

reductions committed to in the 2007 Ozone Plan at 31.8 tpd in 2023. New 

research that has led to these changes is discussed in the Staff Report. The 

ozone situation in the Valley results from a variety of sources, all of which are 

targeted in the 2007 Ozone Plan to reduce emissions and collectively reach 

attainment. 

40. Comment: Rule 4570’s menu approach violates RACT because it permits 

operators to bypass emission reduction measures that are economically and 

technologically feasible in favor of other measures that achieve less, or zero, 

reductions. In the District’s effort to provide flexibility to operators, it has created 

a loophole that simply allows operators to select the least expensive emission 

reduction option. As structured, Rule 4570’s approach cedes the District’s role as 

environmental regulator to the operator, and will inevitably result in missed 

emission reductions. 

Response: Rule 4570 affects a wide variety of operations with differing sizes 

and management practices. Based on the many variations between operators 

subject to Rule 4570, a somewhat flexible requirements approach is necessary. 

The mitigation measures were evaluated to determine which measures would 

achieve the most reductions, namely in feed, silage and housing, and if each 

measure would be technologically and economically feasible to require every 

operator to implement. The mitigation measures in the proposed rule have been 

amended to provide more requirements, as well as make many of the measures 

mandatory. All measures were also evaluated for technological and economic 

feasibility (see Appendices C and E). 

 A-18 Final Staff Report with Appendices For 

Revised Proposed Amendments to Rule 4570 
SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Significant Comments and District Responses October 21, 2010 

41. Comment: Exposed silage piles and leachate are both significant sources of 

VOC emissions and leachate is released from both covered and uncovered piles. 

As such, Table 3.1(B) in the proposed rule requires that one important measure 

be implemented, but allows another separate and necessary measure to be 

ignored. The two options in for silage in Phase I of the rule are clearly not 

redundant. It is a violation of RACT to allow operators to opt out of feasible 

emission controls that are necessary to reduce emissions from a known source. 

Response: To date, no emissions data exists from leachate off of silage piles; 

however, due to the high affinity of ethanol to aqueous solution, emissions from 

leachate are expected to be small. Regardless, the leachate measure has been 

removed from the rule as it is a requirement that is enforced by the Regional 

Water Quality Board. 

The mitigation measures in the proposed rule have been amended to provide 

more requirements, as well as make many of the measures mandatory. All 

measures were also evaluated for technological and economic feasibility (see 

Appendices C and E). 

42. Comment: The District has completed several cost-effectiveness calculations 

for VOC emission control systems using barn-to-biofilter technology with results 

that have ranged widely, from $5,857/ton/year to $84,918/ton/year. A full 

analysis should be conducted on dairies of various sizes to capture the 

efficiencies that might be gained in larger operations. Given that this technology 

holds the most potential for VOC reduction, it is critical that a full and accurate 

analysis be conducted before the Board approves a Revised Rule 4570. 

Response: The District performed a detailed analysis for this measure, which is 

included in Appendix E of the Final Draft Staff Report. 

43. Comment: The Staff Report for the Proposed Amendments to Rule 4570 notes 

that the emission factor is based on a staff review of emerging science. Staff 

admits that the emission factor is still in draft form, and notes that the factor will 

be revised later in 2010. New information identifies silage piles and feed as the 

primary sources of VOC emissions at dairies, making corn silage alone the 

largest source of VOC in the entire Valley. The District should hold back on a 

vote until its recalibration of the emission factor is final. 

Response: Although the emission factor has not been finalized, the report is the 

latest emissions information available for the purposes of rule development. The 

draft emission factor includes all the latest studies performed in California, which 

contains the latest emissions data from silage, feed and multiple other sources at 

a dairy. The emissions data in the report has been critical in tailoring the 

mitigation measures for those sources with the highest emissions (i.e., feed, 

silage, corrals). 

 A-19 Final Staff Report with Appendices For 

Revised Proposed Amendments to Rule 4570 
SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Significant Comments and District Responses October 21, 2010 

44. Comment: The source of data for determination of the flux rates for feed and 

silage are problematic. The Staff Report notes that calculations of exposed 

surface area at dairies are based on reports from dairy industry representatives. 

Such an important data point should be collected based on measurements taken 

by District staff, not regulated entities. 

Response: District staff has reviewed the scientific studies for silage flux and 

believes that the estimations in these studies are valid. As for the face area, staff 

has received additional information from university researchers on actual face 

measurements of 23 Valley dairies which support stakeholders’ initial estimates. 

45. Comment: The claimed emission reductions from Rule 4570 are 

unsubstantiated and should not be claimed until solid science establishes its 

validity. Most of the emission reductions achieved from implementation of the 

mitigation measures are based on a blanket 10% assumed control efficiency 

number. 

Response: There has been a great deal of emissions research conducted over 

the last decade on dairies alone, with millions of dollars spent on this research. 

The latest research has significantly improved the understanding of emissions 

from all the sources at dairies which has also resulted in a better understanding 

of the biological factors and conditions that create VOC emissions from the 

various sources. This understanding has allowed the District to develop 

mitigation measures by changing the biological process or condition of the 

sources to reduce emissions. These mitigation measures are expected to 

reduce emissions by well over 10%, however, the District has taken a 

conservative approach of estimating the reductions from the rule and uses the 

lower end of the control effectiveness range cited in the studies. While this may 

underestimate the actual reductions, the 10% control efficiency better accounts 

for normal variations in the organic processes at CAFs. Therefore, until more 

definitive research data becomes available, the District will continue to 

conservatively estimate the reductions from the rule. Where research indicated 

a higher control efficiency was appropriate, the information was cited for that 

finding. 

46. Comment: Many of the emission control measures listed in Rule 4570 are 

standard operating procedure for dairies. In many cases, dairies will be able to 

comply without making any changes whatsoever. While the District contends 

that not all dairies are currently complying, there is no basis for differentiating 

where reductions are real and where they merely appear on paper. 

Response: Some of the mitigation measures listed in Rule 4570 may now be 

standard practice for some of the largest dairies (due the investment made by 

these facilities as required by the initial Rule 4570, adopted in 2006) but they are 

not standard practice for the dairies that would be subject to the rule as a result 

 A-20 Final Staff Report with Appendices For 

Revised Proposed Amendments to Rule 4570 
SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Significant Comments and District Responses October 21, 2010 

of the proposed lowered threshold. In addition, due to the variability of dairies 

and the constant changes in feed and market prices, dairies not subject to the 

requirements of Rule 4570 can instantly stop performing any practice on their 

dairy at any given time. Rule 4570 would require all facilities to continue to 

comply with the requirements of the rule, regardless of any external factors. 

47. Comment: A mandatory feed measure requires that dairies “push up” TMR in 

feed lanes to three feet from the stanchions within two hours of putting out the 

feed. This fails to account for the movement of the pile. Dairy cows are 

constantly moving the feed around with their snouts as they eat, continuously 

exposing the TMR to the air and releasing VOCs. While the measure might 

appear effective on paper, pushing the feed closer every two hours will yield very 

limited improvement in practice. 

Response: This measure reduces emissions by reducing the surface area of 

the feed placed in the feed lanes. Reducing the surface area would result in a 

decrease in overall VOC emissions. Studies have shown that the VOC flux 

rapidly declines after placement of feed. Although dairy cows may push some of 

the feed back from stanchions, the proposed rule will require that the feed be 

pushed up soon after it has been placed to reduce the area when the flux rate is 

high. In addition, pushing the feed near the fence line places the feed within 

reach of the cows so it can be consumed rather than remaining in the feed lane 

where it can continue to emit VOCs. 

48. Comment: District staff has formulated three options to achieve compaction of 

silage piles to reduce VOC reductions. However, staff concedes that they are 

not in possession of, and have not reviewed, any formal study that establishes 

the effectiveness of this method. Instead, they rely on presentations given by a 

scientist at recent Air District conferences. While this method very well might 

prove to be effective upon further analysis, its use as RACT is premature. 

Response: Although the number of studies that have directly measured VOC 

emissions from silage is limited, there is a significant amount of scientific 

information that supports VOC emission reductions from the silage management 

practices that have been included in the proposed rule. Dr. Charles Krauter of 

California State University, Fresno measured VOC emissions from silage and 

feed while performing a study on dairy emissions. He has indicated that 

preliminary information from the completed study has shown that silage with 

higher density resulted in less total VOC emissions from both the silage piles and 

the total mixed ration (TMR) prepared from the silage and placed as feed for 

animals. 

Packing density is important when making silage because it enables the ensiled 

plant forage to quickly move from an aerobic phase to an anaerobic phase and 

achieve a rapid drop in pH that will hinder further microbial decomposition. The 

 A-21 Final Staff Report with Appendices For 

Revised Proposed Amendments to Rule 4570 
SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix A: Significant Comments and District Responses October 21, 2010 

rapid drop in pH is primarily caused by conversion of soluble carbohydrates to 

nonvolatile lactic acid. Sufficient packing creates the conditions that allow lactic 

acid bacteria to dominate the fermentation rather than other organisms that will 

produce greater amounts of VOCs. Sufficient packing followed by covering of 

piles also reduces yeast counts in the silage. Because yeasts are primarily 

responsible for the production of ethanol during fermentation of silage, reducing 

the number of colony forming units of yeast will reduce the amount of ethanol 

generated and the concentration of ethanol in the silage. Ethanol is one of the 

most volatile compounds found in silage; therefore, reducing ethanol 

concentrations will reduce emissions. 

Increased density in silage piles reduces porosity, which will reduce transport of 

emissions to the atmosphere. Reduced porosity also limits the amount of air that 

penetrates the silage piles that causes aerobic decomposition and heating of the 

piles. . It is scientifically established that the rate of volatilization of compounds is 

affected by the concentration of the compounds, the temperature, and the 

porosity of the medium that contains the compounds. Reducing any of these will 

reduce the rate of transport and volatilization. Therefore, both the direct VOC 

measurements by Dr. Krauter and the established principles of chemistry and 

mass transport support VOC reductions from increased compaction of silage. 

 A-22 Final Staff Report with Appendices For 

Revised Proposed Amendments to Rule 4570