Rule 217 Staff Report Appendix A

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STAFF REPORT

APPENDIX A

EMISSION REDUCTION ANALYSIS FOR PROPOSED AMENDED 

RULE 217 (Large Confined Animal Facilities Permits Required) 

I. SUMMARY 

This staff report appendix A details the estimated emission reductions generated 

by implementation of Proposed Amended Rule 217, Large Confined Animal 

Facilities Permits Required. Currently there are 26 beef feedlots and 1 dairy

under the Imperial County Air Pollution Control District’s (Air District) jurisdiction.

The Imperial County does not currently house any poultry farms or egg ranches. 

Therefore, this document evaluates only emissions produced by dairy and beef 

feedlot facilities. Table 1 summarizes the results of the detailed calculations, 

which are fully displayed in later sections of this document. Based on the data

analyzed herein, the practices listed within proposed Rule 217 would produce an 

estimated reduction of 452.7 tons of VOC per year. 

Table 1: Summary of Reductions

Pollutant VOC Emissions

Dairy Beef 

Feedlot

Uncontrolled Emissions (tons/day) 0.08 5.39

Controlled Emissions (tons/day) 0.06 4.15

Reductions from Proposed Control 

Requirements (tons/day)

0.02 1.24

Reductions from Proposed Control 

Requirements (tons/year)

6.9 452.7

II. INTRODUCTION 

The proposed amended rule would require dairy and beef feedlot facilities above 

the exemption threshold to implement multiple mitigation measures to offset VOC 

emissions. The California Air Resources Board’s (CARB) definition of a Large 

Confined Animal Facility (LCAF) was used as the applicability threshold to satisfy 

state and federal requirements. Air District staff performed a preliminary VOC 

emissions reduction analysis for proposed amended Rule 217 based on the 

information that is currently readily available. This evaluation is based on San 

Joaquin Valley Unified Air Pollution Control District’s (San Joaquin APCD) 

permitting emission factors for dairy and beef feed lot operations. Table 2 

presents a list of mitigation measures proposed by Rule 217 to reduce VOC 

emission for each emission unit at dairy and beef feedlot facilities.
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Table 2: Amount of Mandatory Mitigation Measures from each Emission 

Unit for Dairy and Beef Feedlot Facilities

Beef Feedlot Dairy

Feed 2 of 4 5 of 8

Silage 1 of 3 1 of 3

Milk Parlor 0 of 0 1 of 2

Freestall Barns 0 of 0 3 of 6

Housing 5 of 7 7 of 10

Solid Manure 1 of 2 1 of 3

Liquid Manure 1 of 5 1 of 5

Land Application 2 of 2 2 of 2

TOTAL 12 of 23 21 of 39

III. EMISSION REDUCTION ANALYSIS

A. Background 

In performing the emission reduction analysis, several assumptions were made 

to reflect conservative emission reduction results. These include: 

• All mitigation measures achieve creditable VOC reductions from all 

facilities that use the mitigation measures. Although many of these 

mitigation measures are currently being implemented, it is assumed a 

future reduction of VOC emissions would be accomplished due to the 

mitigation options regardless of whether or not they were in practice prior 

to rule adoption. This assumption is made due to the fact that without the 

presence of proposed Rule 217, these facilities could cease the usage of 

the mitigation measures at any time. Thus, the rule achieves reductions 

by prohibiting the owner/operator from suspending the implementation of 

VOC mitigation measures. 

• In some cases, no data could be found in the literature search on how to 

base a control efficiency factor for these practices. The Air District has

conservatively assumed a minimal 10% control efficiency. As information 

becomes available, it will be added to this methodology. 

• Based on the information provided by our Technical Advisory Committee

(TAC), an assumption is made to the effect that no single dairy in Imperial 

County has freestalls installed within its facilities. In addition, during the 

workshop, stakeholders mentioned that feedlots and dairies in Imperial 

County feed dry grains which do not include silage. Therefore, emissions 

from the feed from feedlot and calf operations are assumed negligible.
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Based on the three major assumptions above, the Air District analyzed the 

efficiency of the least expensive mitigation measures options that 

owners/operators would more than likely choose for adoption. 

B. Emission Factors for Dairies and Beef Feedlots

The Air Resources Board has developed emission factors to estimate TOG and 

ROG emission from dairy and beef feedlot facilities. These emission factors are 

not based on recent numbers or California specific test data. Therefore, the Air 

District has opted to use for this evaluation the current emission factors used in 

San Joaquin APCD. The Air District chose to use San Joaquin’s APCD emission 

factors due to the following reasons: (a) they are accepted by the Air Resources 

Board, and (b) they are divided into emission units which facilitates VOC 

emission evaluation. The values in Table 3 for: manure & feed in housing; enteric 

emissions in housing; enteric emissions in milking center; manure emissions in 

milking center; liquid manure handling; and land application subtotal the current

emission factors used for permitting purposes in San Joaquin APCD. According 

to the Emission Reduction Analysis for Proposed Rule 4570 (Confined Animal 

Facilities), Appendix B, the emission factors used by San Joaquin APCD did not 

include all emission sources. Two sources in which emissions were not counted 

were the solid bedding storage piles and the feed piles outside of the animal 

housing. Since there is research documenting emissions these sources and the 

various VOC control options, San Joaquin APCD staff estimated the emissions 

from these sources by using data from Schmidt's research. These emission 

factors are only used for calculating reductions from mitigation measures that 

control VOC emissions from solid bedding or feed storage piles. 

According to the information obtained from our Technical Advisory Committee, 

none of the dairies in Imperial County have installed freestalls. Therefore, within 

this evaluation it is assumed that dairies operate without the usage of freestalls.

In addition, during the workshop, stakeholders mentioned that feedlots and 

dairies in Imperial County feed dry grains which do not include silage. Therefore, 

emissions from the feed from feedlot and calf operations are assumed negligible. 

Emissions for dairies are shown in the subsequent chart below, Table 3. These 

factors were used to calculate the control factors for dairy control measures. 

The Air District also used San Joaquin APCD permitting emission factors to 

evaluate emissions from dairy and beef feedlots. Based on American Society of 

Agricultural and Biological Engineers (ASAE) Publication D384.1, manure from 

beef cattle in confinement (adult and growing cattle) contains 68% of the amount 

of volatile solids found in a mature dairy cow (lactating and dry cattle). Since the 

amount of volatile solids in the manure is a function of diet and amount of 

manure, emission factors for dairy cattle were multiplied by 0.68 to estimate the 

emissions for beef cattle and are shown in Table 3. These factors were used to 

calculate the control factors for beef feedlot control measures.
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The calculations for dairies and beef feedlots are based on the following 

breakdown of the emission factor by source category:

Table 3: Emission Factors for Dairies and Beef Feedlots

Emission Unit Dairy Emission 

Factors (Dairies 

without 

Freestalls)

Beef Feedlots 

Emission 

Factors

Enteric Emissions in Housing 4.1 lb/hd-yr 5.2 lb/hd-yr

Milk Parlor(s) 0.03 lb/hd-yr 0.0 lb/hd-yr

Corral/Pens 6.6 lb/hd-yr 3.3 lb/hd-yr

Lagoons, Storage Ponds 1.3 lb/hd-yr 0.0 lb/hd-yr

Liquid Manure Land Application 1.4 lb/hd-yr 0.0 lb/hd-yr

Solid Manure Land Application 0.3 lb/hd-yr 0.0 lb/hd-yr

Separated Solid Piles 0.06 lb/hd-yr 0.0 lb/hd-yr

Solid Manure Storage 0.15 lb/hd-yr 2.5 lb/hd-yr

Total 13.94 lb/hd-yr 11.0 lb/hd-yr

C. Control Efficiency Calculation for Dairies

1. ENTERIC EMISSIONS

Option 1: Feeding according to NRC guidelines 

This practice is intended to minimize the excess nutrients fed to the animals at 

the site. Based on research suggesting that nitrogen content in feed is directly 

proportional to nitrogen content in manure, the Air District believes that feeding 

according to the NRC guidelines, which minimizes excess nutrients in the diet, 

would reduce VOC emissions. Following San Joaquin’s APCD rule evaluation, a 

5% reduction is assumed. Given that this practice reduces the content of VOC 

precursors fed to the animal (entering the animal), it will reduce the VOC 

precursors exiting the animal and those being treated in each animal waste 

system. In addition, reductions will occur from feed in the housing and stockpiles 

because there will be less VOC precursors in the feed, which could eventually 

decompose. As a result, the 5% reduction figure again was applied to the facility 

wide emission factors. This is expected to be used by all facilities since 

reductions in excess nutrients in feed, such as protein, would not increase costs 

significantly. Any further labor employed to determine what feed formulations 

would meet NRC guidelines would likely be offset by lower costs for feed due to 

lower nutrient content. The reduction calculations are: 

The baseline is 4.1 lb/hr/yr. yet there are fewer emissions due to the use of the 

NRC feed guidelines. The reduction per measure is: 

Reductions = 4.1 lb/hd-yr x 95% (emissions remaining after implementing Option 
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1) = 3.90 lb/hd-yr 

Option 2, 3 and 4: Three mitigation measures for cleaning feed from housing 

These measures are intended to minimize moisture, surface area for VOCs to 

move from the feed to the atmosphere, and anaerobic digestion due to wet 

conditions and thick depths of animal waste. Data suggests that these practices 

would minimize VOC emissions; however there are no peer-reviewed articles 

that quantify this. Therefore, the Air District assumed a default reduction of 5% 

for each measure. Yet, this assumption only affects the emissions from feed and

these emissions were already reduced by Option 1. 

2. MILK PARLOR PRACTICES 

Flush/clean milk parlor after each milking 

Within the studies performed for the determination of the emission factor for this 

option, this practice was already being carried out. Therefore, the baseline 

assumes that all facilities implement this practice. Thus, no reduction from the 

baseline is anticipated. This measure was included to ensure all current and 

future facilities implement practices accounted for in the baseline emission 

estimate. Following San Joaquin APCD rule evaluation, the baseline is 0.03 

lb/hd-yr.

Reductions = 0.03 lb/hd-yr x 95% (emissions remaining after implementing 

Option 1) = 0.03 lb/hd-yr

3. FREESTALL PRACTICES 

None of the dairies in Imperial County is constructed with feestalls; consequently, 

no reductions are anticipated by freestall practices. However, Rule 217 includes 

mitigation measures for facilities constructed with feestalls with the anticipation

that future facilities may construct feestalls at their site.

4. CORRAL PRACTICES 

Option 1 through 6: All housing measures to clean corals, manage manure 

depth, and minimize moisture are now mandatory. These measures are intended 

to minimize moisture and anaerobic digestion due to wet conditions or thick 

depths of manure that prevents the manure from drying completely and oxygen 

continuing to come in contact with all animal waste in the pens and corrals. Data 

suggests that this would minimize VOC emissions. Following San Joaquin’s 

APCD rule evaluation, a baseline emissions factor of 6.6 lb/hd-yr and a 27.3% 

reduction is assumed (Corrals 22.3% + 5% Feed NRC). The reduction per these 
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measures is: 

Corral emissions = 6.6 lb/hd-yr x 27.3% (emissions from corrals)

= 4.8 lb/hd-yr from corrals 

5. LIQUID MANURE PRACTICES 

All of the lagoon control options 

AEM, 3/03, Vol 69, pg 1710-1720, indicates a 80-93% decrease in emissions 

from swine phototrophic lagoons; ILOC, 1995, pg 80-85, DiSpirito, found the 

same in swine lagoons; and JFB, 70:39-44, Hiraishi, found the same in sewage 

wastewater lagoons. The loading rate contributing to a phototrophic are typically 

found in lagoons utilizing a solid separator, NRCS guidelines for anaerobic 

lagoon design, and microaerobic nutrient management. However, these studies 

were for swine and not cattle. Based on AP42 by U.S. EPA, swine emit 63.5% of 

the volatile solids that cattle do. Therefore, in order to be conservative, staff 

assumed that cattle lagoons are 63.5% as efficient as swine lagoons (63.5% x 

80% = 50%). According to San Joaquin APCD rule evaluation, the baseline is 1.3

lb/hr/yr. yet there are fewer emissions due to the use of the NRC feed guidelines. 

The reduction per measure is: 

Reductions = 1.3 lb/hd-yr x 95% (emissions remaining after implementing Option 

1) = 1.24 lb/hd-yr 

6. SOLID MANURE STORAGE/SEPARATED SOLIDS PRACTICES 

Cover piles outside the pens 

This measure is intended to minimize moisture and anaerobic digestion due to 

wet conditions. There is no data regarding the amount of emissions from the 

manure storage piles, therefore staff conservatively estimated the separated 

solids and the manure piles emit approximately the same amount of VOC. Since 

there is little data regarding reductions, staff assumed a default reduction of 10% 

for cover piles mitigation measure. The reduction per measure is: 

Separated solid Practice Piles = 0.06 lb/hd-yr x 95% (emissions remaining after 

implementing Option 1) = 0.06 lb/hd-yr

Solid Manure Storage = 0.15 lb/hd-yr (piles) x 85% (10% emissions remaining 

after implementing Cover Piles Measure + 5% Option 1) = 0.13 lb/hd-yr 

reductions. 

7. SOLID MANURE LAND APPLICATION PRACTICES 

These practices are intended to rapidly land incorporate the manure or waste 
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water. The soil is expected to act as a biofilter since it is an organic media with 

significant microbial populations and airflow. Research suggests biofilters range 

in efficiency from 10% to 90% depending on how they are maintained. 

Conservatively staff assumed 50% control. The baseline emissions from crop 

application are 0.3 lb/hd-yr. 

The reduction per measure is = 0.3 lb/hd/year x 95% (emissions remaining after 

implementing Option 1) = 0.3 lb/hd-yr

8. TOTAL REDUCTIONS 

The total percent reductions can be calculated by assuming the percent 

reductions for each mitigation measure above.

Controlled Emission Factor = 10.46 lb/hd-yr

The total percent reduction = ((13.94 – 10.46)/13.94) x 100

The total percent reduction = 25 %

D. Control Efficiency Calculation for Beef Feedlots

1. ENTERIC EMISSIONS

Option 1: Feeding according to NRC guidelines 

This practice is intended to minimize the excess nutrients fed to the animals at 

the site. Based on research suggesting that nitrogen content in feed is directly 

proportional to nitrogen content in manure, the Air District believes that feeding 

according to the NRC guidelines, which minimizes excess nutrients in the diet, 

would reduce VOC emissions. Following San Joaquin APCD rule evaluation, a 

5% reduction is assumed. Given that this practice reduces the content of VOC 

precursors fed to the animal (entering the animal), it will reduce the VOC 

precursors exiting the animal and those being treated in each animal waste 

system. In addition, reductions will occur from feed in the housing and stockpiles 

because there will be less VOC precursors in the feed, which could eventually 

decompose. As a result, the 5% reduction figure again was applied to the facility 

wide emission factors. This is expected to be used by all facilities since 

reductions in excess nutrients in feed, such as protein, would not increase costs 

significantly. Any further labor employed to determine what feed formulations 

would meet NRC guidelines would likely be offset by lower costs for feed due to 

lower nutrient content. The reduction calculations are: 

The baseline is 5.2 lb/hr/yr. yet there are fewer emissions due to the use of the 

NRC feed guidelines. The reduction per measure is: 
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Reductions = 5.2 lb/hd-yr x 95% (emissions remaining after implementing Option 

1) = 4.94 lb/hd-yr 

Option 2, 3 and 4: Three mitigation measures for cleaning feed from housing 

These measures are intended to minimize moisture, surface area for VOCs to 

move from the feed to the atmosphere, and anaerobic digestion due to wet 

conditions and thick depths of animal waste. Data suggests that these practices 

would minimize VOC emissions; however there are no peer-reviewed articles 

that quantify this. Therefore, the Air District assumed a default reduction of 5% 

for each measure. Yet, this assumption only affects the emissions from feed and 

these emissions were already reduced by Option 1. 

2. CORRAL PRACTICES 

Option 1 through 4: All housing measures to clean corrals, manage manure 

depth, and minimize moisture. These are intended to minimize moisture and 

anaerobic digestion due to wet conditions or thick depths of manure that prevents 

the manure from drying completely and oxygen continuing to come in contact 

with all animal waste in the pens and corrals. Data suggests that this would 

minimize VOC emissions. A baseline emission factor of 3.3 lb/hd-yr is assumed. 

Following San Joaquin APCD rule evaluation, a 27.3% reduction is assumed 

(Corrals 22.3% + 5% Feed NRC). The reduction per these measures is: 

Corral emissions = 3.3 lb/hd-yr x 27.3% (emissions from corrals) = 3.3 lb/hd-yr x 

(1-0.273) = 2.4 lb/hd-yr

3. SOLID MANURE LAND APPLICATION PRACTICES 

Option 9 & 10: All methods for crop application. 

These practices are intended to rapidly land incorporate the manure or waste 

water. The soil is expected to act as a biofilter, since both biofilters and soil are 

organic media with significant microbial populations and airflow. Research 

suggests biofilters range in efficiency from 10% to 90% depending on how they 

are maintained. Conservatively, staff assumed 50% control. The baseline 

emission from crop application is 2.5 lb/hd-yr. The seven moisture minimization 

practices utilized as mitigation measures for animal housing means there is less 

moisture in the manure and therefore less potential for VOC emissions. There

also lies less potential for VOC emissions due to the implementation of a NRC 

diet. Thus, the baseline emissions should also be reduced by 10%, which is the 

control efficiency of having a diet based on the NRC guidelines. The reduction 

per measure is: 

Options 9 & 10 Reductions = 2.5 lb/hd/year x 90% (emissions remaining after 

implementing Option 1) x 50% (control efficiency) = 1.13 lb/hd-yr 
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5. TOTAL REDUCTIONS 

Controlled Emission Factor = 8.47 lb/hd/year

The total percent reductions can be calculated by summing the percent 

reductions for each mitigation measure above. 

The total percent reduction = ((11 – 8.47)/11) x 100

The total percent reduction = 23 %

E. Rule 217 Emissions and Reductions 

As previously stated, 26 beef feedlots and 1 dairy operate within the jurisdiction 

of the Air District, with a total cattle population, as of 2013, of 361,888 heads. 

This figure, along with San Joaquin APCD emission factors and control 

efficiency, formed the basis for estimating total VOC reductions in Imperial 

County due to the implementation of the various mitigation measures found 

within proposed Rule 217. Based on this information, it is estimated that a VOC 

reduction from dairies will be 6.96 tons per year, whereas beef feedlots will see a 

reduction of 452.7 tons per year. Table 4 summarizes the emission reduction 

calculations from the control measures included in the rule:

Table 4 Cattle-Related VOC Emission Reductions

Source Category Dairy Cattle Beef Feedlot

2013 Cattle Population 4,000 357,888

Uncontrolled Emission Factor 

(lbs VOC/head/year)

13.94 11.0

Uncontrolled VOC Emissions 

(ton/day)

0.08 5.39

Control Efficiency of Mitigation 

Measures 

25% 23%

Controlled Emission Factor 

(lbs VOC/head/day)

10.46 8.47

Controlled VOC Emissions 

(tons/day)

0.06 4.15

VOC Reductions 

(tons/day)

0.02 1.24

VOC Reductions 

(tons/year)

6.9 452.7