AQ-2023-005-RULE327-REPORT TO THE BOARD OF SUPERVISORS.PDF

Maricopa County — Formal (2024-11-06)

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Air Quality Department 
301 W. Jefferson St., Suite 410  
Phoenix, Arizona 85003 
 
P: 602-506-6010 
E: AQMail@maricopa.gov 
 
 
 
 
 
 
 
 
Executive Summary of the Report to the Board of Supervisors 
Prepared by Maricopa County Air Quality Department 
Board Hearing Date: 
December 11, 2024  
Case Number/Title:  
AQ-2023-005- Rule 327 (Organic Material Processing) 
Agenda Item:  
 
(Pending) 
Supervisor Districts:  
All Districts 
The Maricopa County Air Quality Department (MCAQD) complied with all statutory and county 
policies throughout this rulemaking process. Per the Enhanced Regulatory Outreach Program 
(EROP) Policy: “In addition to the required staff report, an executive summary of the report 
including an overview of stakeholder input and staff responses will be provided to the Board 
of Supervisors at least one week prior to any Board of Supervisors’ public hearing.” 
Overview of the Report to the Board of Supervisors: 
On November 7, 2022, the U.S. Environmental Protection Agency (EPA) reclassified portions 
of Maricopa County from “marginal” to “moderate” nonattainment with respect to the 2015 
National Ambient Air Quality Standard (NAAQS) for ozone. Sections 172(c) and 182(b) of the 
Clean Air Act (CAA) require jurisdictions that are classified as moderate or higher 
nonattainment to submit a state implementation plan (SIP) revision to provide for volatile 
organic compound (VOC) emission reductions to attain the ozone NAAQS by the applicable 
attainment date.  The SIP revision must include provisions addressing reasonable further 
progress, an attainment demonstration, and contingency measures amongst other provisions. 
In response to the reclassification, MCAQD identified organic material processing as an 
activity where potential emission reductions of volatile organic compounds could be made to 
assist towards attainment of the ozone NAAQS. Organic material processing includes organic 
material composting, stockpiling of small organic material, or any combination thereof. These 
processes are known to produce VOC emissions through controlled or inadvertent biological 
decomposition of organic materials that contribute to ground-level ozone formation.

Page 2 of 47 
On February 7, 2024, EPA revised the annual fine particulate matter (PM2.5) NAAQS from 12.0 
micrograms per cubic meter (µg/m3) to 9.0 µg/m3. As a proactive response to this lower 
standard, Rule 327 is also proposing to limit ammonia emissions, which are a precursor to the 
formation of PM2.5. Maricopa County has not yet been designated nonattainment for the 2024 
PM2.5 standard, but it is anticipated a portion of the County will be designated nonattainment. 
In addition to production of ammonia and ozone forming precursors, organic material 
processing operations are also a source of air pollutant emissions from spontaneous 
combustion due to internal organic material pile heating. Biological processes produce a 
temperature high enough to initiate and sustain exothermic chemical reactions. Mismanaged 
and poorly monitored large organic material piles can lead to, at a minimum, smoldering piles, 
or in more severe cases a large flaming fire. Emissions from this type of spontaneous 
combustion include NAAQS criteria pollutants nitrogen oxides (NOx) and PM2.5. The proposed 
rule provides organic material processing management provisions to mitigate air pollutant 
emissions produced by the spontaneous combustion of large piles of organic material. 
Rule 327 will be considered a contingency measure for achieving the 2015 ozone NAAQS as 
required by Section 172(c)(9) of the CAA. As such, it will become effective subsequent to the 
EPA making a determination that either the Phoenix-Mesa nonattainment area failed to attain 
the 2015 ozone NAAQS by the attainment date or failed to make reasonable further progress. 
Due to the proposed rule containing a compliance schedule of 180 days after rule adoption, 
provisions of the rule will become effective 180 days after local rule adoption or an EPA 
determination, whichever occurs last. 
Overview of Stakeholder Input and Staff Responses: 
During the rulemaking process, MCAQD has received written comments from three (3) 
stakeholders. One (1) stakeholder expressed opposition and two (2) stakeholders expressed 
neither support nor opposition to the rulemaking.

Maricopa County 
Air Quality Department 
Planning and Analysis Division 
Report to the 
Board of 
Supervisors 
 
Rule 327 (Organic 
Material Processing) 
December 2024

Board of Health Meeting Date: 
October 28, 2024 
Board Hearing Date: 
December 11, 2024 
Case Number/Title:  
AQ-2023-005-Rule 327 (Organic Material Processing) 
Agenda Item: 
(Pending) 
Supervisor Districts: 
All Districts 
Applicant:  
Staff 
Request: 
Approve creation of Maricopa County Air Pollution Control 
Regulations, Rule 327 (Organic Material Processing) and 
approve submission of the rule as a revision to the Arizona 
State Implementation Plan (SIP). 
 
On November 7, 2022, the U.S. Environmental Protection 
Agency (EPA) reclassified portions of Maricopa County from 
“marginal” to “moderate” nonattainment with respect to the 
2015 National Ambient Air Quality Standard (NAAQS) for 
ozone. Sections 172(c) and 182(b) of the Clean Air Act 
(CAA) require jurisdictions that are classified as moderate or 
higher nonattainment to submit a state implementation plan 
(SIP) revision to provide for volatile organic compound 
(VOC) emission reductions to attain the ozone NAAQS by the 
applicable attainment date.  The SIP revision must include 
provisions addressing reasonable further progress, an 
attainment demonstration, and contingency measures 
amongst other provisions. 
 
In response to the reclassification, MCAQD identified organic 
material processing as an activity where potential emission 
reductions of volatile organic compounds could be made to 
assist towards attainment of the ozone NAAQS. Organic 
material processing includes organic material composting, 
stockpiling of small organic material, or any combination 
thereof. These processes are known to produce VOC 
emissions through controlled or inadvertent biological 
decomposition of organic materials that contribute to 
ground-level ozone formation.   
 
On February 7, 2024, EPA revised the annual fine particulate 
matter (PM2.5) NAAQS from 12.0 micrograms per cubic 
meter (µg/m3) to 9.0 µg/m3. As a proactive response to this 
lower standard, Rule 327 is also proposing to limit ammonia 
emissions, which are a precursor to the formation of PM2.5. 
Maricopa County has not yet been designated 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 4 of 68

nonattainment for the 2024 PM2.5 standard, but it is 
anticipated a portion of the County will be designated 
nonattainment. 
 
In addition to production of ammonia and ozone forming 
precursors, organic material processing operations are also 
a source of air pollutant emissions from spontaneous 
combustion due to internal organic material pile heating. 
Biological processes produce a temperature high enough to 
initiate and sustain exothermic chemical reactions. 
Mismanaged and poorly monitored large organic material 
piles can lead to, at a minimum, smoldering piles, or in more 
severe cases a large flaming fire. Emissions from this type 
of spontaneous combustion include NAAQS criteria 
pollutants nitrogen oxides (NOx) and PM2.5. The proposed 
rule provides organic material processing management 
provisions to mitigate air pollutant emissions produced by 
the spontaneous combustion of large piles of organic 
material. 
 
Rule 327 will be considered a contingency measure for 
achieving the 2015 ozone NAAQS as required by Section 
172(c)(9) of the CAA. As such, it will become effective 
subsequent to the EPA making a determination that either 
the Phoenix-Mesa nonattainment area failed to attain the 
2015 ozone NAAQS by the attainment date or failed to make 
reasonable further progress. Due to the proposed rule 
containing a compliance schedule of 180 days after rule 
adoption, provisions of the rule will become effective 180 
days after local rule adoption or an EPA determination, 
whichever occurs last. 
Support/Opposition: 
During the rulemaking process, MCAQD has received written 
comments from three (3) stakeholders. One (1) stakeholder 
expressed opposition and two (2) stakeholders expressed 
neither support nor opposition to the rulemaking.  
Staff 
Recommendation:  
 
Approve 
 
Board of Health 
Recommendation: 
Approve 
Additional Comments: 
This regulatory change is following the Enhanced Regulatory 
Outreach Program (EROP) Policy and workflow process. The 
County Manager briefed the Board of Supervisors regarding 
this rulemaking in July 2023. Stakeholder Workshops were 
held on March 12, 2024, and August 28, 2024. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 5 of 68

The Board of Health approved initiation of regulatory change 
on April 22, 2024, and a Notice of Proposed Rulemaking was 
posted on the EROP website on September 20, 2024. On 
October 28, 2024, the Board of Health made a 
recommendation to the Board of Supervisors to approve the 
creation of Rule 327. 
 
A newspaper notice of the Board of Supervisors public 
hearing will be published in the Arizona Business Gazette on 
November 7, 2024, and November 11, 2024. This regulatory 
change will take effect immediately upon approval by the 
Board of Supervisors. 
Presented By: 
Philip A. McNeely, R.G., Director 
Prepared By: 
Planning and Analysis Division 
Attachments: 
Preamble required by Arizona Revised Statutes (A.R.S.) § 
49-471.07 (See the Draft Notice of Final Rulemaking) 
Summary of the proposed regulatory change (See Item 4 of 
the Draft Notice of Final Rulemaking) 
Analysis of input received during the process and how that 
input was responded to (See Item 9 of the Draft Notice of 
Final Rulemaking) 
Language of proposed regulatory change or amendment 
(See the Draft Notice of Final Rulemaking) 
Minutes from Board of Health meeting 
Copies of all written and electronic Stakeholder input 
 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 6 of 68

Maricopa County 
Air Quality Department 
Planning and Analysis Division 
Draft Notice of 
Final 
Rulemaking 
Rule 327 (Organic 
Material Processing) 
December 2024

Draft Notice of Final Rulemaking 
Maricopa County Air Pollution Control Regulations 
Regulation III – Control of Air Contaminants 
Rule 327 (Organic Material Processing) 
The Maricopa County Air Quality Department (MCAQD) is proposing to create Rule 327 
(Organic Material Processing). The Control Officer is posting this Draft Notice of Final 
Rulemaking on the Maricopa County Enhanced Regulatory Outreach Program (EROP) website 
as part of the Report to the Board of Supervisors, in accordance with the Maricopa County 
EROP Policy. This notice includes the preamble, as prescribed in Arizona Revised Statutes 
(A.R.S.) § 49-471.05, and the full text of the rule. This notice also includes a list of all previous 
notices posted on the Maricopa County EROP website addressing the proposed rule and the 
concise explanatory statement prescribed in A.R.S. § 49-471.07(B). 
Preamble 
1.
Statutory authority for the rulemaking (A.R.S. § 49-471.05(1)):
A.R.S. §§ 49-112, 49-474, 49-479 and 49-480
2.
Name and address of department personnel with whom persons may communicate
regarding the rulemaking (A.R.S. § 49-471.05(2)):
Name:
Will Adrian or Kimberly Butler 
Maricopa County Air Quality Department 
Planning and Analysis Division 
Address: 
301 W. Jefferson St., Suite 410 
Phoenix, AZ 85003 
Telephone: 
602-506-6010 
Fax: 
602-506-6179 
Email: 
AQPlanning@maricopa.gov 
Online: 
Submit a Comment 
3.
Rulemaking process (A.R.S. § 49-471.05(3)):
This rulemaking is following procedures identified in state statutes and the Maricopa
County EROP Policy.
County Manager Briefing:
July 21, 2023 
Stakeholder Workshops:
March 12, 2024 
Return to list of attachments
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 8 of 68

August 28, 2024 
Board of Health Meeting to Initiate Regulatory 
Change: 
April 22, 2024 
Notice of Proposed Rulemaking: 
September 20, 2024 
Board of Health Meeting to Recommend Approval 
to the Board of Supervisors: 
October 28, 2024 
Board of Supervisors Formal Meeting to Set 
the Public Hearing:  
November 6, 2024 
Board of Supervisors Public Hearing: 
December 11, 2024 
4.
Explanation of the rule, including the control officer's reasons for initiating the
rulemaking (A.R.S. § 49-471.05(4)):
On November 7, 2022, the U.S. Environmental Protection Agency (EPA) reclassified
portions of Maricopa County from “marginal” to “moderate” nonattainment with respect
to the 2015 National Ambient Air Quality Standard (NAAQS) for ozone. Sections 172(c)
and 182(b) of the Clean Air Act (CAA) require jurisdictions that are classified as
moderate or higher nonattainment to submit a state implementation plan (SIP) revision
to provide for volatile organic compound (VOC) emission reductions to attain the ozone
NAAQS by the applicable attainment date.  The SIP revision must include provisions
addressing reasonable further progress, an attainment demonstration, and contingency
measures amongst other provisions.
In response to the reclassification, MCAQD identified organic material processing as an
activity where potential emission reductions of volatile organic compounds could be
made to assist towards attainment of the ozone NAAQS. Organic material processing
includes organic material composting, stockpiling of small organic material, or any
combination thereof. These processes are known to produce VOC emissions through
controlled or inadvertent biological decomposition of organic materials that contribute
to ground-level ozone formation.
On February 7, 2024, EPA revised the annual fine particulate matter (PM2.5) NAAQS from
12.0 micrograms per cubic meter (µg/m3) to 9.0 µg/m3. As a proactive response to this
lower standard, Rule 327 is also proposing to limit ammonia emissions, which are a
precursor to the formation of PM2.5. Maricopa County has not yet been designated
nonattainment for the 2024 PM2.5 standard, but it is anticipated a portion of the County
will be designated nonattainment.
In addition to production of ammonia and ozone forming precursors, organic material
processing operations are also a source of air pollutant emissions from spontaneous
combustion due to internal organic material pile heating. Biological processes produce
a temperature high enough to initiate and sustain exothermic chemical reactions.
Mismanaged and poorly monitored large organic material piles can lead to, at a
minimum, smoldering piles, or in more severe cases a large flaming fire. Emissions
Return to list of attachments
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 9 of 68

from this type of spontaneous combustion include NAAQS criteria pollutants nitrogen 
oxides (NOx) and PM2.5. The proposed rule provides organic material processing 
management provisions to mitigate air pollutant emissions produced by the 
spontaneous combustion of large piles of organic material. 
Rule 327 will be considered a contingency measure for achieving the 2015 ozone 
NAAQS as required by Section 172(c)(9) of the CAA. As such, it will become effective 
subsequent to the EPA making a determination that either the Phoenix-Mesa 
nonattainment area failed to attain the 2015 ozone NAAQS by the attainment date or 
failed to make reasonable further progress. Due to the proposed rule containing a 
compliance schedule of 180 days after rule adoption, provisions of the rule will become 
effective 180 days after local rule adoption or an EPA determination, whichever occurs 
last. 
5. 
Studies relied on in the control officer's evaluation of or justification for the rule and 
where the public may obtain or review the studies, all data underlying the studies, any 
analysis of the studies and other supporting material (A.R.S. § 49-471.05(5)). 
2018 International Fire Code as Amended by the City of Phoenix. 
 
https://codes.iccsafe.org/content/PHXFC2018P1 
California Integrated Waste Management Board. (2008). Emissions Testing of Volatile 
Organic Compounds from Greenwaste Composting at the Modesto Compost 
Facility in the San Joaquin Valley. Report prepared for the California Integrated 
Waste Management Board, Contract IWM04072. 
Organic Waste Processing Facilities Recommended Management Guidelines. (n.d.). 
https://sustainability-innovation.asu.edu/resourceinnovation/wp-
content/uploads/sites/18/2017/01/OrganicWasteProcessingFacilities-RMGs-
FINAL.pdf  
San Joaquin Valley Air Pollution Control District. (2010, Rev. 2023). Compost VOC 
Emission Factors. 
https://ww2.valleyair.org/media/hdsoobtp/criteria-compost-emission-factors-
report-final-voc-nh3-3-21-23.pdf 
San Joaquin Valley Air Pollution Control District. (2009). Comparison of Mitigation 
Measures for Reduction of Emissions Resulting from Greenwaste Composting. 
 
https://valleyair.org/busind/pto/emission_factors/Criteria/Criteria/Composting/
FINAL-COMPOST-STUDY-REPORT.pdf 
6. 
An economic, small business and consumer impact statement (A.R.S. § 49-
471.05(6)): 
The following discussion addresses each of the elements required for an economic, 
small business and consumer impact statement, as prescribed by A.R.S. §§ 41-1055, 
subsections A, B and C, and 41-1035: 
An identification of the proposed rulemaking, including all of the following (A.R.S. § 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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41-1055(A)(1)): 
This rulemaking is proposing to create Rule 327. 
(a) The conduct and its frequency of occurrence that the rule is designed to change 
(A.R.S. § 41-1055(A)(1)(a)). 
MCAQD is proposing the creation of Rule 327 to limit emissions of VOCs and 
ammonia from organic material processing operations and prevent emissions of 
PM2.5 and NOx from combustion of organic material processing operations. 
More specifically, VOC and ammonia emissions are proposed to be controlled from 
the stockpiling and composting of organic material. Several requirements are 
proposed as compliance options for stockpiling of organic material in order to 
prevent inadvertent decomposition of organic material. Composting requirements 
include watering and applying a finished compost cover to organic material piles. In 
addition, a composting compliance option for the use of an aerated static pile 
system (ASP) has been proposed which includes a requirement to apply a finished 
compost cover upon initial pile formation. 
Fire prevention provisions are proposed in order to prevent the spontaneous 
combustion of large piles of organic material due to internal pile heating. Rule 
provisions help ensure fire prevention through requirements for pile layout and 
management, as well as access to material-handling equipment to aid in the event of 
an emergency. 
(b) The harm resulting from the conduct the rule is designed to change and the 
likelihood it will continue to occur if the rule is not changed (A.R.S. § 41-
1055(A)(1)(b)). 
Rule 327 will provide a dedicated rule to limit emissions of VOCs and ammonia from 
organic material processing operations and prevent emissions of PM2.5 and NOx 
from combustion of organic material processing operations. The requirements 
proposed in Rule 327 will improve the control of these emissions. In the absence of 
these requirements, it will be more difficult for Maricopa County to attain applicable 
federal air quality standards and prevent emissions of PM2.5 and NOx from 
combustion of organic material processing operations.  
(c) The estimated change in frequency of the targeted conduct expected from the rule 
change (A.R.S. § 41-1055(A)(1)(c)).  
Rule 327 is based upon best management practices for organic material processing 
operations, with the intent of implementing requirements already in use or easily 
adopted if not already used. The majority of stakeholders who have provided input 
have communicated current compliance with a significant portion of the proposed 
rule requirements, mainly emission control requirements under stockpiling and 
composting, as well as fire prevention. Through stakeholder feedback and site-visits 
MCAQD does not anticipate a significant change in operations for the majority of 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 11 of 68

stakeholders applicable to the proposed rulemaking, however if any change were to 
result MCAQD would anticipate it to be of the nature of monitoring, reporting, and 
recordkeeping in order to demonstrate compliance with the rule. 
A brief summary of the information included in the economic, small business and 
consumer impact statement (A.R.S. § 41-1055(A)(2)). 
This proposed rulemaking should not have a significant economic impact on small 
businesses or consumers in Maricopa County. The proposed provisions of the rule are 
based upon stakeholder feedback and cost-effective measures using best management 
practices. The proposed requirements include a tiered approach for emission controls 
based on throughput of organic material at affected businesses. The proposed fire 
prevention requirements contain provisions most affected businesses currently 
implement, for example an approved fire prevention plan and access to firefighting 
equipment. 
Name and address of agency employees who may be contacted to submit or request 
additional data on the information included in the economic, small business and 
consumer impact statement (A.R.S. § 41-1055(A)(3)). 
Name: 
Will Adrian or Kimberly Butler 
Maricopa County Air Quality Department 
Planning and Analysis Division 
Address: 
301 W. Jefferson St., Suite 410 
Phoenix, AZ 85003 
Telephone: 
602-506-6010 
Fax: 
602-506-6179 
Email: 
AQPlanning@maricopa.gov 
Online: 
Submit a Comment 
An identification of the persons who will be directly affected by, bear the costs of or 
directly benefit from the proposed rulemaking (A.R.S. § 41-1055(B)(2)). 
This proposed rulemaking will directly affect new and existing owners or operators of 
organic material processing operations in Maricopa County that produce or receive 200 
or more wet tons per year of any combination of green material, food material, and less 
than or equal to 75 percent animal manure or poultry litter. Backyard and community 
composting are exempt from the proposed requirements, as well as operations that 
satisfy all of the of the following: organic material is processed on-site, used on-site, 
and no financial transaction occurs for receipt of processed organic material. 
This proposed rulemaking will benefit the people of Maricopa County in that it will result 
in the reduction of ground-level ozone and PM2.5. The rulemaking will also benefit the 
people of Maricopa County in that it will prevent the spontaneous combustion of 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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organic material processing operations, thereby preventing the release of air pollutants 
as well as the expenditure of resources to mitigate and put out fires. 
A cost benefit analysis of the following: 
(a) The probable costs and benefits to the implementing agency and other agencies 
directly affected by the implementation and enforcement of the proposed 
rulemaking (A.R.S. § 41-1055(B)(3)(a)). 
MCAQD anticipates accounting for incurred compliance costs by requiring appliable 
operations to obtain a Non-Title V air quality permit with a cost of $680, which would 
include Rule 327 requirements. Facilities may already currently possess a stationary 
dust-generating general permit, with a cost of $360. 
(b) The probable costs and benefits to a political subdivision of this state directly 
affected by the implementation and enforcement of the proposed rulemaking 
(A.R.S. § 41-1055(B)(3)(b)). 
This rulemaking should not impose any significant new costs on any political 
subdivision of this state. 
(c) The probable costs and benefits to businesses directly affected by the proposed 
rulemaking, including any anticipated effect on the revenues or payroll 
expenditures of employers who are subject to the proposed rulemaking (A.R.S. § 
41-1055(B)(3)(c)). 
This proposed rulemaking should not have a significant economic impact on organic 
material processing businesses in Maricopa County. The proposed provisions of the 
rule are based upon stakeholder feedback and cost effective measures using best 
management practices. The proposed requirements include a tiered approach for 
emission controls based on throughput of organic material at affected businesses. 
The proposed fire prevention requirements contain provisions most affected 
businesses currently implement, for example an approved fire prevention plan and 
access to firefighting equipment.  
The anticipated cost applicable to businesses directly affected is $680, for obtaining 
a Non-Title V air quality permit which would include Rule 327 requirements. Facilities 
may already currently possess a stationary dust-generating general permit, with a 
cost of $360. 
A general description of the probable impact on private and public employment in 
businesses, agencies and political subdivisions of this state directly affected by the 
proposed rulemaking (A.R.S. § 41-1055(B)(4)). 
This proposed rulemaking should have no impact on private or public employment in 
businesses, agencies, and political subdivisions of this state. 
A statement of the probable impact of the proposed rulemaking on small businesses. 
The statement shall include: 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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(a) An identification of the small businesses subject to the proposed rulemaking 
(A.R.S. § 41-1055(B)(5)(a)). 
This proposed rulemaking will directly affect new and existing small business 
owners or operators of organic material processing operations in Maricopa County 
that produce or receive 200 or more wet tons per year of any combination of green 
material, food material, and less than or equal to 75 percent animal manure or 
poultry litter. Backyard and community composting, as defined by the rule, as well as 
operations that satisfy all of the of the following: organic material is processed on-
site, used on-site, and no financial transaction occurs for receipt of processed 
organic material, are all exempt from compliance with the rule. 
(b) The administrative and other costs required for compliance with the proposed 
rulemaking (A.R.S. § 41-1055(B)(5)(b)). 
This proposed rulemaking should not have a significant cost impact for compliance. 
The proposed provisions of the rule are based upon stakeholder feedback and cost 
effective measures using best management practices. As these proposed 
requirements consist of existing best management practices, there should be little 
to no additional administrative or other cost required to implement for compliance. 
Significant emission control techniques of application of water and a finished 
compost cover should already be present on-site and in use. The proposed fire 
prevention requirements contain provisions most affected businesses currently 
implement, for example an approved fire prevention plan and access to firefighting 
equipment.  
The anticipated cost applicable to businesses directly affected is $680 for obtaining 
a Non-Title V air quality permit which would include Rule 327 requirements. Facilities 
may already currently possess a stationary dust-generating general permit, with a 
cost of $360. 
(c) A description of the methods that the agency may use to reduce the impact on 
small businesses (A.R.S. § 41-1055(B)(5)(c)). 
i. Establish less stringent compliance or reporting requirements in the rule for 
small businesses (A.R.S. § 41-1035(1)). 
Rule 327 contains less stringent organic material composting requirements than 
were originally proposed to address stakeholder feedback including the 
development of a tiered approach for emission controls based on throughput of 
organic material at affected businesses. Smaller businesses, those with a 
smaller throughput, have less stringent compliance requirements. 
Additionally, the proposed rule does not apply to organic material processing 
operations in Maricopa County that produce or receive less than 200 wet tons 
per year of any combination of green material, food material, and less than or 
equal to 75 percent animal manure or poultry litter. Backyard and community 
composting, as defined by the rule, as well as operations that satisfy all of the of 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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the following: organic material is processed on-site, used on-site, and no financial 
transaction occurs for receipt of processed organic material are also exempt 
from compliance with the rule. 
ii. Establish less stringent schedules or deadlines in the rule for compliance or 
reporting requirements for small businesses (A.R.S. § 41-1035(2)). 
The requirements of the rule will become effective 180 days following a 
determination by the U.S. Environmental Protection Agency that either of the 
following triggering events has occurred in a. or b.: 
a. The Phoenix-Mesa 2015 ozone NAAQS nonattainment area failed to attain the 
2015 ozone NAAQS by the Moderate area attainment date; 
b. The Phoenix-Mesa 2015 ozone NAAQS nonattainment area failed to make 
reasonable further progress under the 2015 ozone NAAQS. 
c. If EPA makes such a determination as described in a. or b. prior to adoption 
of the rule, the requirements of the rule will become effective 180 days 
following adoption.  
Essentially, the rule provides a 6 month compliance timeframe after it becomes 
effective. 
iii. Consolidate or simplify the rule's compliance or reporting requirements for 
small businesses (A.R.S. § 41-1035(3)). 
MCAQD’s Business Assistance Unit provides a collection of recordkeeping 
templates, handbooks, field guides, flyers, and other resources to consolidate 
and simplify compliance and reporting requirements, particularly for small 
businesses with limited resources. The Business Assistance Unit also provides 
information and technical assistance to business owners related to air quality 
rules and regulations, courtesy site visits and on-site training, and rule 
interpretation and education if needed to ensure compliance. MCAQD anticipates 
resources and services as the aforementioned to be developed by the Business 
Assistance Unit in order to consolidate and simplify the proposed rule’s 
compliance and reporting. 
iv. Establish performance standards for small businesses to replace design or 
operational standards in the rule (A.R.S. § 41-1035(4)). 
No performance standards for small businesses have been established to 
replace design or operational standards in the rule. 
v. Exempt small businesses from any or all requirements of the rule (A.R.S. § 41-
1035(5)). 
This proposed rule does not apply to small business owners or operators of 
organic material processing operations in Maricopa County that produce or 
receive less than 200 wet tons per year of any combination of green material, 
food material, and more than 75 percent animal manure or poultry litter. In 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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addition, backyard and community composting, as defined by the rule, as well as 
operations that satisfy all of the of the following: organic material is processed 
on-site, used on-site, and receive no financial gain from sale of the organic 
processed material, are exempt from compliance with the rule. 
(d) The probable cost and benefit to private persons and consumers who are directly 
affected by the proposed rulemaking (A.R.S. § 41-1055(B)(5)(d)). 
This rulemaking should not result in any significant costs for private persons and 
consumers. 
A statement of the probable effect on state revenues (A.R.S. § 41-1055(B)(6)). 
There is no projected change in consumer purchase patterns and, thus, no projected 
impact on state revenues from sales taxes. 
A description of any less intrusive or less costly alternative methods of achieving the 
purpose of the proposed rulemaking, including the monetizing of the costs and 
benefits for each option and providing the rationale for not using nonselected 
alternatives (A.R.S. § 41-1055(B)(7)). 
The purpose of this rulemaking is to create Rule 327 in order to obtain emission 
reductions of VOCs to assist in achieving attainment of the ozone NAAQS. Due to 
Maricopa County being reclassified as a moderate nonattainment area with respect to 
the 2015 8-hour ozone NAAQS, Sections 172(c) and 182(b) of the CAA require 
jurisdictions that are classified as moderate or higher nonattainment to submit a SIP 
revision to provide for VOC emission reductions to attain the ozone NAAQS by the 
applicable attainment date. Failure to do so could result in sanctions and imposition of 
a FIP under the CAA which could adversely affect Maricopa County. 
A description of any data on which a rule is based with a detailed explanation of how 
the data was obtained and why the data is acceptable data (A.R.S. § 41-1055(B)(8)). 
See Section 5 for a description and links from where the data was obtained. 
7. 
The proposed effective date of the rule (A.R.S. § 49-471.05(7)): 
The proposed adoption date of Rule 327 is December 11, 2024. Due to this rule being 
adopted as a contingency measure for achieving the 2015 ozone NAAQS, the proposed 
effective date of this rulemaking will be one of the following: 
• If the proposed rule is adopted by the Maricopa County Board of Supervisors on 
the proposed adoption date of December 11, 2024, and before determination of 
the EPA as described in section 102.2, then the requirements of Rule 327 shall 
not become effective until 180 days after a determination of the EPA as 
described in section 102.2. 
• If the proposed rule is adopted by the Maricopa County Board of Supervisors 
after determination of the EPA as described in section 102.2, then the 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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requirements of the rule will become effective 180 days after the proposed 
effective date of December 11, 2024.  
8. 
Such other matters as are prescribed by statute and that are applicable to the county 
or to any specific rule or class of rules (A.R.S. § 49-471.05(8)): 
Under A.R.S. § 49-479(C), a county may not adopt a rule or ordinance that is more 
stringent than the rules adopted by the Director of the Arizona Department of 
Environmental Quality (ADEQ) for similar sources unless it demonstrates compliance 
with the applicable requirements of A.R.S. §49-112. 
§ 49-112 County regulation; standards 
§ 49-112(A) 
When authorized by law, a county may adopt a rule, ordinance or regulation that is more 
stringent than or in addition to a provision of this title or rule adopted by the director or 
any board or commission authorized to adopt rules pursuant to this title if all of the 
following requirements are met: 
1. The rule, ordinance or regulation is necessary to address a peculiar local condition. 
2. There is credible evidence that the rule, ordinance or regulation is either; 
(a) Necessary to prevent a significant threat to public health or the environment that 
results from a peculiar local condition and is technically and economically 
feasible. 
(b) Required under a federal statute or regulation, or authorized pursuant to an 
intergovernmental agreement with the federal government to enforce federal 
statutes or regulations if the county rule, ordinance or regulation is equivalent to 
federal statutes or regulation. 
3. Any fee or tax adopted under the rule, ordinance or regulation does not exceed the 
reasonable costs of the county to issue and administer the permit or plan approval 
program. 
§ 49-112(B) 
When authorized by law, a county may adopt rules, ordinances or regulations in lieu of a 
state program that are as stringent as a provision of this title or rule adopted by the 
director or any board or commission authorized to adopt rules pursuant to this title if 
the county demonstrates that the cost of obtaining permits or other approvals from the 
county will approximately equal or be less than the fee or cost of obtaining similar 
permits or approvals under this title or any rule adopted pursuant to this title. If the state 
has not adopted a fee or tax for similar permits or approvals, the county may adopt a 
fee when authorized by law in the rule, ordinance or regulation that does not exceed the 
reasonable costs of the county to issue and administer that permit or plan approval 
program. 
MCAQD is in compliance with A.R.S. §§ 49-112(A) and (B). Rule 327 is a rule creation 
and there is no previous version of the rule. This new rulemaking is considered to be in 
addition to provisions of A.R.S. Title 49 or rules adopted by the Director of ADEQ or any 
Board or Commission authorized to adopt rules pursuant to A.R.S. Title 49.  
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In accordance with A.R.S. §§ 49-112(A) and (B), MCAQD is authorized to adopt Rule 327 
because the following requirements have been met:  
1. Rule 327 is necessary to address a peculiar local condition, in that Maricopa County
fails to meet the 2015 8-hour NAAQS for ozone. (§ 49-112(A)(1)) 
2. The adoption of Rule 327 is required by federal law (Section 172(c)(9) of the Clean Air
Act) to address contingency measures for state implementation nonattainment plans. 
(§ 49-112(A)(2)(b))  
3. The new fee associated with this proposed rulemaking is $680 and does not exceed
reasonable costs as described above. (A.R.S. § 49-112 (A)(3) and A.R.S § 49-112 (B)) 
9.
List of all previous notices posted to the Maricopa County EROP website addressing
the proposed rule and a concise explanatory statement, as prescribed by A.R.S. § 49-
471.07(B):
(a)  List of all previous notices posted to the Maricopa County EROP website
addressing the proposed rule: 
Notice 
Date of Posting 
Briefing Notification to County Manager: 
August 15, 2023 
Notices of Stakeholder Workshops: 
February 27, 2024 
August 13, 2024 
Notice of Board of Health Meeting to Initiate 
Regulatory Change: 
April 8, 2024  
Notice of Proposed Rulemaking: 
September 20, 2024 
Notice of Board of Health Meeting to Recommend 
Approval to the Board of Supervisors: 
October 14, 2024 
(b) The following discussion addresses each of the elements required for a concise 
explanatory statement, as prescribed by A.R.S. § 49-471.07(B): 
i.
A description of any change between the proposed rule or ordinance, the final
rule or ordinance or notice of final supplemental rule or ordinance.
The following changes were made after the Notice of Proposed Rulemaking was 
published on September 20, 2024.
•
Added operation and maintenance language to § 303.2. The added language
reads as follows:
“Operate and maintain the ASP in accordance with the manufacturer’s
specifications or written procedures developed by the owner or operator
based on good air pollution control practices for minimizing emissions, and
comply with either of the following:”
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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•
Added phrase “as required in § 303.1 b.” to § 304.2 to improve rule clarity.
This section now reads:
“An owner or operator shall cover the surface area of at least the top third of
each pile with finished compost cover so that there is at least six inches in
height of finished compost cover as measured at the peak of each pile. An
owner or operator shall cover the surface area of each pile as described
within three hours of initial pile formation and, as required in § 303.1 b., within
three hours after each turning of the pile for at least three turns of each pile.
For any piles that are mechanically turned after 2:00 pm, an exception to the
three-hour limit can be made, which allows the owner or operator to cover the
surface area of at least the top third of each pile with finished compost cover
within three hours of the start of organic material composting operations the
following calendar day.”
•
Added recordkeeping language to § 503.3 associated with the added
operation and maintenance language in § 303.2. The added language reads
as follows:
“c. Record the date, time, and pressure drop of the duct system vented to the
biofilter, at least once per week.”
“d. Maintain a copy of the manufacturer’s specifications or written
procedures developed by the owner or operator based on good air pollution
control practices for minimizing emissions, used to comply with § 303.2, on
site and available to the Control Officer upon request.”
ii. A summary of the comments and arguments for and against the notice and the
county’s response to the comments and arguments.
The following discussion evaluates the arguments for and against the rule and
includes responses to comments received on the proposed rule or the preamble
in the Notice of Proposed Rulemaking. MCAQD received written comments from
three stakeholders. All comments were reviewed and evaluated by MCAQD. A
link to a copy of the stakeholder comments is provided.
Stakeholder #1: Comment #1 submitted on September 6, 2023.
Comment #1:
I am a teacher and looking for someone to come to my school to explain
Aquaponics through vector control.
Response #1:
Comment does not pertain to the rulemaking. No revisions were made to the rule
in response.
Stakeholder #2: Comments #2 through #11 submitted on March 12, 2024.
Return to list of attachments
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I have provided a series of specific comments on the proposed rules. However, I 
would like to express opposition (and, frankly, dismay) over this rule. This will 
have the impact of either reducing the amount of compost my farm is able to 
reduce or dramatically increasing the amount of fossil fuel I have to burn to 
comply with the rules. Princeton University's Project Drawdown reports "that 
composting organic waste versus landfilling it can reduce more than 50% of 
carbon dioxide-equivalent greenhouse gas emissions", but the emission savings 
from landfill diversion is only one benefit of composting. 
What is not as talked about nor accounted for in the analysis on composting by 
Project Drawdown, is the benefit of applying compost to soil. When the end-use 
of compost is considered, composting is indirectly tied to a dozen or more 
solutions presented in Project Drawdown from green roofs and conservation 
agriculture, to plant-based diets. 
Compost is a natural way to provide nutrients to plants to enhance productivity 
while storing carbon in soils. As such, compost not only reduces carbon 
emissions by the aforementioned amount, but shares emissions savings through 
many of the other climate solutions in Project Drawdown by acting as a carbon 
sink or “sponge” that can soak up emissions currently in the atmosphere and 
limit the impacts of climate change which is already causing devastating 
wildfires, flooding, and droughts to name a few. 
A regulation which reduces composting or, even worse, requires the extensive 
use of fossil fuel, is counter-productive. 
The science this rule is based on is decades old and not rigorous. The net impact 
is highly likely to be to release more Methane gas and do much more harm than 
good. 
Response #2:  
The primary reason for this rulemaking is to limit the emissions of VOCs from 
organic material processing operations. VOCs contribute to the formation of 
ozone and portions of Maricopa County are currently designated as a moderate 
nonattainment area with respect to the 2015 NAAQS for ozone. As such, 
Maricopa County must implement measures to reduce VOCs to assist towards 
attainment of the ozone NAAQS. Organic material processing operations such as 
composting are known to emit VOCs; therefore, MCAQD is proposing a rule to 
limit those emissions. MCAQD recognizes the benefits of composting but must 
also implement measures to limit the formation of ozone.  
Additionally, the science relied upon in this rulemaking includes, as cited in 
section 5 of the preamble, the Compost Emission Factors Report published by 
San Joaquin Valley Air Pollution Control District. This report was recently revised 
on March 21, 2023 making the science behind this rule current. 
Comment #2:
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Overall: This rule is based on measurements and assessments that are almost 
20 years old and not widely replicated. They seek to manage primarily CO2 
emissions. Two important points: First, the overall greenhouse gases released 
from food and green waste are at least 50% lower from composting than from 
burying that waste in a landfill. If this rule has the effect of reducing composting, 
the impact on the overall quality of air in Maricopa County gets worse. Second, 
many of the rules will require significantly more “loader time” to make compost. 
My loaders burn diesel fuel – so a rule that requires 6 hours of loader time per 
windrow per turn, will burn approximately 40 gallons of fossil fuel. The EPA 
reports that every gallon of diesel fuel burned creates about 8,887 grams of CO2 
or almost 36 Kilos of CO2 (based on CA study California Air Resources Board). 
They estimated of process emissions from composting are 0.007 MTCO2/ton (7 
KG per ton) or between 300 – 400 KG per row (of which the target is 50% - 60% 
reduction). The rule is asking us to spend significant cost and 36 KG of CO2 to 
save 150 KG, which seems inefficient. 
Plus, the reduction ignores the widely accepted recognition of the following 
benefits from the USE of compost: 
• Decreased water use for similar growing results
• Decreased Soil Erosion
• Reduced Fertilizer Use
• Reduced Herbicide Use
Response #3:  
The science relied upon in this rulemaking includes, as cited in section 5 of the 
preamble, the Compost Emission Factors Report published by San Joaquin 
Valley Air Pollution Control District. This report was recently revised on March 21, 
2023 making the science behind this rule current.  
The purpose of the rulemaking is to limit emissions of VOC and ammonia, as well 
as prevent the emissions of NOx and PM2.5. Greenhouse gases are not regulated 
by this rule. As mentioned in Response #2, the primary reason for this rulemaking 
is to limit VOC emissions from organic material processing operations to assist 
towards attainment of the ozone NAAQS and thereby improve overall air quality 
in Maricopa County. 
Additionally, many proposed requirements in the rule were revised during the 
rulemaking process to address stakeholder feedback. For example, facilities with 
an organic material throughput below 10,000 tons per year (Section 302) are only 
required to apply finished compost cover upon initial pile formation, instead of 
the previously proposed requirement to apply finished compost cover upon initial 
pile formation and after each pile turning for the duration of the active 
composting phase. This revised requirement will reduce “loader time” and 
thereby reduce fuel use. 
Comment #3:
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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Comment #4:  
102 Applicability: This rule applies to very small operations. An operation 
processing 201 tons is going to product about 70 -90 yards of compost. This will 
force very small operations to comply with complex rules and reporting 
regulations. We recommend this be revised to operations larger than 10 acres or 
that the rule be bifurcated into rules for large commercial operations (10 acres or 
larger) and small operations. 
Response #4:  
The rule applicability is in part based upon MCAQD's permitting threshold for 
VOCs, 0.5 tpy. Based upon organic material stockpiling and composting VOC 
emission factors (0.2 lbs/wet ton/day and 3.58 lbs/wet ton, respectively) 
provided in the Compost Emission Factors Report published by San Joaquin 
Valley Air Pollution Control District (link in section 5 of the preamble), an 
operation with a throughput of approximately 200 tpy would emit approximately 
0.5 tpy of VOCs. 
Additionally, Rule 327 contains less stringent organic material composting 
requirements than were originally proposed to address stakeholder feedback 
including the development of a tiered approach for emission controls based on 
throughput of organic material at affected businesses. Smaller businesses, those 
with a smaller throughput, have less stringent compliance requirements. 
Comment #5:  
301.3 Cover: This rule seems aimed at an environment where rain is a concern. 
The average number of rainy days in Phoenix is 33. This rule asks us to perform a 
rather difficult task 100% of the time, when it is only relevant less 10% of time. 
We recommend this be replaced with “cover only material that will begin active 
composting if hydrated, prior to and during a predicted rain event” 
Response #5: 
Section 301 is intended to reduce emissions from inadvertent decomposition of 
organic material. Compliance with the requirements for use of a waterproof 
cover under section 301.3 is only required if the owner or operator chooses this 
compliance option. This compliance option prevents inadvertent decomposition 
by mitigating excess water accumulation in the stockpile. 
Section 301 has been revised to allow for an extended stockpiling timeframe of 
organic material. Specifically, Section 301.4 allows an owner or operator to 
stockpile organic material beyond 10 days as long as they can demonstrate the 
material has a moisture content of less than 40% using a moisture test described 
in the rule. This demonstration must be measured at least once per calendar 
week. This provision was added in acknowledgement of the surrounding dry, arid 
climate and ability of facilities to maintain relatively dry material given low annual 
rainfall.  
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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Comment #6:  
302.1 b. Composting Requirement: This rule restricts my ability to manage my 
piles based on my expert experience and consultants. We frequently turn piles at 
day 4. And, while rare, we occasionally do not turn pile more than twice. 
Response #6: 
The requirement that piles be turned at a specific frequency has been removed 
from the rule. The frequency with which piles must be turned is no longer 
specified, but requirements remain, i.e. moisture content, whenever the owner or 
operator does turn a pile. 
Comment #7:  
302.1 c. Composting Requirement: Adding six inches of finished compost after 
every turn is impractical with our footprint. Our windrows are set far enough 
apart for a tractor with a turner, but not far enough apart for a loader to apply the 
finished compost after each turn. We could add the finished compost when the 
row was initially established, but on subsequent turns. We estimate the cost of 
this rule to be $4.61 per yard of compost (incremental cost) 
Response #7: 
The requirement to apply finished compost cover upon initial pile formation and 
after each pile turning for the duration of the active phase has been revised for 
facilities with an organic material throughput below 10,000 tons per year (Section 
302). Facilities with an organic material throughput below 10,000 tons per year 
are only required to apply finished compost cover upon initial pile formation. 
Comment #8:  
303.2 Composting Requirement: Again, adding six inches of finished compost 
after every turn is impractical with our footprint. Our windrows are set far enough 
apart for a tractor with a turner, but not far enough apart for a loader to apply the 
finished compost after each turn. We could add the finished compost when the 
row was initially established, but on subsequent turns. We estimate the cost of 
this rule to be $4.61 per yard of compost (incremental cost). 
Response #8: 
The requirement to apply finished compost cover upon initial pile formation and 
after each pile turning for the duration of the active phase has been revised for 
facilities with an organic material throughput below 10,000 tons per year (Section 
302). Facilities with an organic material throughput below 10,000 tons per year 
are only required to apply finished compost cover upon initial pile formation. 
Comment #9:  
304.2 Pile Layout: It is not clear if this applies just to inputs or to compost as 
well. It should not apply to active compost piles – if they meet the hydration 
requirements, it is impossible for them to catch fire. The other requirements are 
covered by the rules for a Fire Prevention Plan – they are site specific and should 
be reviewed as such. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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Response #9: 
An owner or operator of an organic material process operation with an approved 
Fire Prevention Plan as described in Section 305 does not have to comply the pile 
layout requirements in Section 305.2 (previously Section 304.2). Only owners and 
operators without an approved Fire Prevention Plan must comply with this 
section. The pile layout requirements in Section 305.2 were developed using fire 
prevention guidelines recommended by the Resource Innovation and Solutions 
Network (RISN). RISN is a program of the Rob and Melani Walton Sustainability 
Solutions Services at Arizona State University, in partnership with the city of 
Phoenix’s Reimagine Phoenix initiative.  
Comment #10:  
501.3 Records: This one makes me very nervous. I can’t see how my proprietary 
logs should be made available to the general public. 
Response #10: 
Recordkeeping and reporting by a facility used to verify compliance are made 
available to the public through public records request, to ensure the public 
maintains the ability to independently verify air quality regulation compliance. 
However, records and information may be made confidential by compliance with 
confidentiality of information and trade secret requirements of Rule 100 (General 
Provisions and Definitions) of the Maricopa County Air Pollution Control 
Regulations. 
Comment #11:  
502 Records: Much of our stockpile feedstock comes in a continuous flow (we 
get daily drops from various suppliers). We don’t have the manpower or 
processes to record each delivery and the stockpiles are not discrete entities – 
we are actively receiving and using the material. This should be re-written to 
reflect how these processes actually work. 
Response #11: 
Section 502 requires records of when each stockpile was initially formed and the 
date and action taken on each stockpile to satisfy the stockpiling requirements in 
the rule. This information is needed to determine compliance with the stockpiling 
rule requirements. 
Stakeholder #3: Comments #12 through #23 submitted on August 5, 2024. 
Comment #12:  
202 Alternative Mitigation Measure: Please clarify what the expectation is for 
demonstrating reduction in VOC. If source testing is required to demonstrate the 
reduction of VOCs, that would be cost prohibitive to the composting industry in 
Maricopa County resulting in increased landfilling of organics rather than 
production of nutrient rich compost. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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Response #12: 
Per feedback from the EPA, the option to implement an alternative mitigation 
measure to comply with the stockpiling and/or composting requirements was 
removed from the rule because Rule 327 will be considered a contingency 
measure as discussed in Section 4 of the Preamble. As such, per 172(c)(9) of the 
CAA, all provisions in the rule must take effect without further action by the 
County or the Administrator.  
In response to removal of alternative mitigation measures from the rule, MCAQD 
added an additional composting compliance option in Section 303 allowing for 
the use of an Aerated Static Pile System. 
Comment #13:  
301 – 301.4 Stockpiling: The City agrees that inbound material should be 
processed as soon as possible and that stockpiles need to be effectively 
managed to reduce the risk of fire. If the stockpiles of green material are 
managed in compliance with fire code requirements, the risk of fire and odors 
can be reduced. There are operational conditions that may require unground and 
ground green material be stockpiled longer than 10 days including stockpiling 
feedstock for optimal biofilter media production and biofilter replacement 
(porous woody waste and logs), seasonal increases in inbound green material 
volumes including from monsoon storms, and equipment downtimes. Optimal 
feedstock and size of the biofilter media is essential for the biofilter’s optimal 
lifespan and operation of negative aeration in advanced compost technology 
systems. Depending on the size of the biofilter, it takes time to accumulate the 
necessary volume of the specific green materials needed for the biofilter 
replacement. If there are restrictions on stockpiling biofilter media, aerated pile 
facilities may be restricted to operate only positive aeration which is not always 
optimal to maintain ideal composting temperatures. Additionally, facilities may 
need to consider landfilling some of the inbound green material or using as 
alternative daily cover, resulting in increased emissions with transportation and 
landfilling compared to composting. 
Section 301.3 states, “Cover the organic material with a waterproof cover,” if the 
unground and ground green material stockpiles are covered for extended periods 
of time. If the waterproof cover is secured 
around the pile, restricting airflow and oxygen in the pile, there is a risk of 
creating anaerobic conditions and increased temperatures of the piles, resulting 
in associated odors and fire risk. 
We recommend updating the stockpiling requirements to focus on the facility’s 
demonstrated management and monitoring of the green material stockpiles 
instead of imposing a 10-day limit. The City supports consecutive day limits on 
food waste stockpiling for odor control. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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Response #13: 
Section 301 has been revised to allow for an extended stockpiling timeframe of 
organic material. Specifically, Section 301.4 allows an owner or operator to 
stockpile organic material beyond 10 days as long as they can demonstrate the 
material has a moisture content of less than 40% using a moisture test described 
in the rule. This demonstration must be measured at least once per calendar 
week. 
Comment #14:  
302.1 b and c Organic Material Composting Requirements: 
b. A minimum of five consecutive days apart for each turning of the pile may not 
always be optimal due to operations and environmental conditions. Maybe 
consider regulating the minimum turns required for active composting or provide 
a range in the number of days between each turn. 
c. Please see comment on section 303.2. If a six-inch finished compost cover is 
required, it should be limited to the first zone or pile in active composting only. 
Requiring biocover application with each turn of piles or zones in active 
composting would significantly reduce the processing capacity of the facility and 
increase operational costs. 
Applying a six-inch biocover in the first zone or pile of active composting only 
should also be sufficient to control VOCs. During the 2023 United States 
Composting Council Conference session on Research to Improve Compost 
Facility Air Emissions Permitting, Engineered Compost Systems staff presented 
that VOCs are the highest within the first five days of the active composting 
process and then drop off significantly for the duration of the active composting 
process. 
Response #14: 
The requirement that piles be turned at a specific frequency has been removed 
from the rule. The frequency with which piles must be turned is no longer 
specified, but requirements remain, i.e. moisture content, whenever the owner or 
operator does turn a pile. 
The draft rule has been revised to limit the application of a finished compost 
cover, under certain circumstances, to only when the initial pile is formed. More 
specifically, Section 303.2 requires the application of a finished compost cover 
only upon initial pile formation when using an Aerated Static Pile System under 
noncontinuous negative pressure. 
Comment #15:  
302.2 Implement a Control Officer and EPA approved alternative mitigation 
measure that demonstrates at least a 60% reduction, by weight, in VOC 
emissions. 
Can the standard be clarified as to the basis of the 60% reduction? 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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Response #15: 
Per feedback from the EPA, the option to implement an alternative mitigation 
measure to comply with the composting requirements was removed from the 
rule because Rule 327 will be considered a contingency measure as discussed in 
Section 4 of the Preamble. As such, per 172(c)(9) of the CAA, all provisions in the 
rule must take effect without further action by the County or the Administrator.  
In response to removal of alternative mitigation measures from the rule, MCAQD 
added an additional composting compliance option in Section 303 allowing for 
the use of an Aerated Static Pile System. 
Comment #16:  
303.1 Watering Systems: This section of the rule is excessively detailed as to the 
watering methods. Recommend simplifying this section that 40% moisture 
should be maintained and demonstrated with a compliant moisture test 
conducted as described in 303.3 before each turn. 
Response #16: 
The watering systems requirements of Section 304 (previously Section 303) are 
intended to provide sequential steps for the application of water and when to use 
the compliant moisture test within Section 304.3. This is important to the rule as 
compliance moisture tests conducted at the wrong time may yield inaccurate 
results, or if the results show insufficient water then there must be a requirement 
to add water, as present in 304.1a. and b.(2). 
Comment #17:  
303.2 Finished Compost Cover: Researchers at Washington State University 
(WSU) and at Engineered Compost System have air emissions data that indicate 
that surface irrigation can be at least as effective as applying a biocover to 
reducing VOC emissions from positively aerated piles. WSU will be conducting 
another round of compost air emissions trials later this year to further test the 
validity of the existing data sets. The work is funded by the Washington State 
Department of Ecology. It is recommended to wait for the results of this research 
before requiring the application of a finished compost cover in this rule. Please 
also see comment on section 302.1 c. 
Response #17: 
Rule 327 will be considered a contingency measure for achieving the 2015 ozone 
NAAQS as required by Section 172(c)(9) of the CAA. It will be included in the 
Maricopa 2015 Ozone Moderate Area Plan that must be submitted to the EPA by 
May 17, 2025, to avoid sanctions by the EPA.  
Comment #18:  
303.3 Compliant Moisture Test: The methods listed as a and b are the most 
common field tests for moisture levels. Maintaining at least 40% moisture is 
important during active composting, but moisture levels can temporarily adjust 
when the piles are ready for screening to reduce clogging within the screen. It is 
recommended that that the 40% moisture requirement is specific to the active 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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composting and curing phases. If moisture levels reduce for screening, water 
needs to be applied around the screening process to prevent opacity and fire 
risk. 
Response #18: 
Organic material composting requirements in Sections 302 and 303, including 
moisture content requirements, apply to the active phase of composting as 
specified in the rule. 
Comment #19:  
Section 500: Monitoring and Records 
Will there be templates or assistance provided by Maricopa County on the 
required monitoring and records to ensure compliance prior to official 
implementation of this new rule? 
Response #19: 
MCAQD’s Business Assistance (BA) Unit will be available to provide assistance 
on rule requirements prior to official implementation of the rule.  
The BA Unit provides resources to consolidate and simplify compliance and 
reporting requirements, particularly for small businesses with limited resources. 
The BA Unit also provides information and technical assistance to business 
owners related to air quality rules and regulations, courtesy site visits and on-site 
training, and rule interpretation and education if needed to ensure compliance. 
MCAQD anticipates resources and services will be developed by the BA Unit in 
order to consolidate and simplify the proposed rule’s compliance and reporting. 
Comment #20:  
502 Stockpiling Recordkeeping: Please see comments on 301-301.4 
Response #20: 
Section 301 has been revised to allow for an extended stockpiling timeframe of 
organic material. Specifically, Section 301.4 allows an owner or operator to 
stockpile organic material beyond 10 days as long as they can demonstrate the 
material has a moisture content of less than 40% using a moisture test described 
in the rule. This demonstration must be measured at least once per calendar 
week. 
Comment #21:  
503.2 Organic Material Composting Operations Records: Please see comments 
on 302.1 b and c, and 303.2. 
Response #21: 
See Responses #14 and #17 of this section. 
Comment #22:  
503.3 Alternative Mitigation Measure Records: Please see comments on 202 and 
302.2. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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Response #22: 
See Responses #12 and #15 of this section. 
Comment #23:  
504.2 Smoldering and/or Smoke Self-Inspection Log: The twice daily requirement 
seems excessive. It is recommended that the requirement be daily. Please clarify 
that this log would need to be maintained daily and only presented upon 
inspection or at the request of Maricopa County 
Response #23: 
Spontaneous combustion of organic material may occur quickly and may not be 
easily visible as it can originate deep within the pile. Self-inspection should occur 
on a frequent enough basis so that smoldering or smoking does not increase in 
severity, and therefore act to prevent possible fires from developing. 
Stakeholder #3: Comments #24 through #31 submitted on September 10, 
2024. 
Comment #24:  
Denali appreciates the opportunity to comment on the proposed regulations as 
well as the lengths staff has gone to involve stakeholders through the rule 
development process. Unfortunately, we have significant questions regarding the 
potential regulations described in your latest draft of Rule 327. We have concerns 
over this proposed regulatory package and its impacts on compost facilities 
throughout the District’s jurisdiction. Indeed, should these regulations be adopted 
in their current draft form, they will create an economic burden on our industry 
that will hamper numerous composting operations throughout the County. While 
our industry members are ardent supporters of environmental protection and the 
implementation of sustainable practices that will benefit the citizens of the state, 
we believe the control measures and management practices described in Rule 
327 do not reflect real world conditions at facilities, will be burdensome in their 
application, and may hamper the ability of many cities and counties to continue 
landfill diversion activities. 
Response #24: 
The proposed provisions of the rule are based upon stakeholder feedback and 
cost effective measures using best management practices. The proposed rule 
has been revised many times to incorporate stakeholder feedback. These 
revisions include adding an aerated static pile system as a compliance option for 
composting operations. 
Comment #25:  
Scope 
The scope of emissions reductions required under this Rule includes both ozone 
precursor volatile organic compounds (VOCs) and particulate matter resulting 
from fire events. While Denali supports reasonable rules which protect the 
environment – and understand the current responsibilities the Department has in 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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meeting Clean Air Act compliance – the current rule language, as written, is in 
part not able to be implemented at certain types of operations, placing a 
significant economic burden on the facilities within the affected sector. 
Response #25: 
The proposed provisions of the rule are based upon stakeholder feedback and 
cost effective measures using best management practices. The proposed rule 
has been revised many times to incorporate stakeholder feedback. These 
revisions include adding an aerated static pile system as a compliance option for 
composting operations. 
Comment #26:  
Denali – along with our experienced consultant team – is happy to meet with 
District staff to discuss the significant challenges with the current rule language 
and the impractical nature of applying it at the City of Phoenix’s facility that we 
operate. 
Response #26: 
MCAQD met with commenter and made several revisions to draft rule language 
to address their concerns. 
Comment #27:  
Policy Recommendations 
In its current form, draft Rule 327 seeks to implement control measures that are 
tailored for windrow composting – both with proven compost cap and irrigation 
methods that have demonstrated emissions reductions at facilities in California 
where regulatory conditions have existed for over a decade – they do not appear 
to consider the type of turned aerated static pile (TASP) technology at our facility 
that is specifically designed to control VOC emissions and odors, requiring a 
significant investment in the control technologies and operations currently 
employed. 
Response #27: 
The proposed rule has been revised to incorporate provisions for aerated static 
pile systems under Section 303.2 Aerated Static Pile System (ASP). These 
provisions include requirements for both negative and positive pressure settings, 
use of a biofilter, and application of a finished compost cover. 
Comment #28:  
Technical Concerns 
While we understand the District’s desire to achieve the highest feasible 
emissions reductions, the economic burden placed on composting operators by 
use of a Finished Compost Cover is both excessive and uncertain. The excessive 
costs lie in the loss of revenue caused by reducing throughput and sales of 
finished product at the facilities, as 20% to over 50% of site capacity will be 
occupied by finished compost; the required volume of finished compost for the 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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“cap” would represent a one-time loss of sales, but the loss of processing 
capacity would be permanent. The operational and capital costs of a Finished 
Compost Cover are largely uncertain – given the lack of any available, proven 
technology with which to apply the cover or an assessment of the corresponding 
increased capital costs for equipment, operation and maintenance costs, or 
additional labor costs. 
Current technology use for installation of the Finished Compost Cover will cause 
an additional impact on facility capacity and throughput. Absent the development 
of any new technological advancement in compost application, current use of 
front loaders would be the sole functional option for delivery of the finished 
compost to the tops of the windrows. Commercial composting facilities typically 
maximize use of their available space by maintaining aisles of no more than ten 
feet between windrows. Use of a front loader for compost application of a cap 
will necessitate using aisles of twenty feet or more to allow a turning radius for 
the loader to attain a proper angle of address for efficiently and effectively 
dumping their load on the top of the windrow. The additional spacing between 
windrows will reduce the available composting space by approximately 40%, 
limiting throughput volume,revenues and overall, the amount of organic residuals 
that should be recycled vs going to landfill. 
At the City of Phoenix operations, given the current use of a negatively-aerated, 
turned windrow system, will be forced to apply a compost cap eight times (every 
three days for each of the eight separate piles created) as the active composting 
material is turned from aeration-zone to aeration-zone, adding a significant 
volume of materials across the full process. 
Response #28: 
The proposed rule has been revised to incorporate provisions for aerated static 
pile systems under Section 303.2 Aerated Static Pile System (ASP). Incorporated 
revisions include reducing the number of times a finished compost cover must 
be applied when using an ASP. Section 303.2 b.(2) states that "upon initial pile 
formation cover the piles with a finished compost cover as described in § 304.2". 
After covering the initial pile with a finished compost cover the owner or operator 
does not have to cover subsequent piles as they are turned. 
Comment #29:  
We fully support the current recommendations on assessing moisture content, 
as our experienced operators can readily attain accurate results with reasonable 
success (within 5%) by use of the manual squeeze ball test. 
Response #29: 
MCAQD appreciates your support of the rule requirement. 
Comment #30:  
We do not believe that the requirement of section 304.3 (c) for corrective action 
at 160⁰F is a well-reasoned approach to fire mitigation. This temperature is 
common in composting piles and is far from a fire-critical level. Actively aerated 
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composting piles have no demonstrated threat of fire generation (as stated 
previously regarding spontaneous combustion potential) and there is no 
evidence that, even at 180⁰F, fires from active composting have occurred. While 
temperatures above 180⁰F can reasonably be expected to limit microbial activity 
and lead to diminished composting activity, the fire risk is still significantly low. A 
reasonable approach may be to provide an exception for facilities using forced 
aeration and turning, as the buildup of low flash point gases will only represent a 
spontaneous combustion threat if they are allowed to build up over several 
weeks. 
Response #30: 
The corrective action temperature points of 160 and 180 degrees Fahrenheit are 
recommended by local fire department personnel and are based on the pile 
management temperatures found within the Organic Waste Processing Facilities 
Recommended Management Guidelines. A link to the guidelines can be found in 
section 5 of the Preamble.   
Comment #31:  
Denali believes that the Department needs to take prudent steps to reassess the 
current language in Rule 327, while also taking into account the potential future 
management of green and food waste materials in agricultural land application, 
and/or disposed of in landfills, should composting operations become non-
existent or prohibitively costly. We have not seen where the Department, to date, 
has estimated the increased NOx and Particulate Matter emissions created by 
the need to apply the compost cap repeatedly. 
Denali has a commitment to effective recycling and environmental protection 
that is unwavering. The continued success of green and food waste recycling 
programs is dependent upon the development of cost-effective, practical 
regulations that will protect the environment in balance with the substantial 
benefits of composting operations to the sustainable future of our state and 
nation. We look forward to continued participation in the development of this 
regulatory package, with an eye on results that are responsive to the need for 
landfill diversion—as provided by composting operators—while simultaneously 
improving the air quality of the state. 
In closing, we believe that the Department’s proposed timeline for adoption of 
Rule 327 (by the end of this year) may need to be delayed, given the very short 
period of time available for review and comment on the highly complex draft Rule 
and, given that there are numerous technical questions related to proper 
implementation of a compost cap and irrigation system, required sampling and 
testing protocols, and time needed to review potential revisions that may result in 
response to comments from stakeholders. If you have any questions please do 
not hesitate to contact [us]. 
Response #31: 
The proposed provisions of the rule are based upon stakeholder feedback and 
cost effective measures using best management practices. The proposed rule 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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has been revised many times to incorporate stakeholder feedback. These 
revisions include reducing the number of times a finished compost cover must 
be applied under certain circumstances.  
Rule 327 will be considered a contingency measure for achieving the 2015 ozone 
NAAQS as required by Section 172(c)(9) of the CAA. It will be included in the 
Maricopa 2015 Ozone Moderate Area Plan that must be submitted to the EPA by 
May 17, 2025, to avoid sanctions by EPA. 
Exact Wording of the Rule 
MARICOPA COUNTY AIR POLLUTION CONTROL REGULATIONS 
REGULATION III – CONTROL OF AIR CONTAMINANTS 
RULE 327 (ORGANIC MATERIAL PROCESSING) 
INDEX 
SECTION 100 – GENERAL 
101 
PURPOSE 
102 
APPLICABILITY 
103 
EXEMPTIONS 
SECTION 200 – DEFINITIONS 
201 
ACTIVE PHASE 
202 
AERATED STATIC PILE SYSTEM (ASP) 
203 
ANIMAL MANURE 
204 
AUTHORITY HAVING JURISDICTION FOR FIRE PREVENTION AND LIFE SAFETY 
205 
BACKYARD COMPOSTING 
206 
BIOFILTER 
207 
COMMUNITY COMPOSTING 
208 
COMPOST 
209 
COMPOSTING 
210 
CURING PHASE 
211 
FINISHED COMPOST 
212 
FINISHED COMPOST COVER 
213 
FOOD MATERIAL 
Return to list of attachments
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214 
GREEN MATERIAL 
215 
INDEPENDENT WATERING SYSTEM 
216 
INTEGRATED WATERING SYSTEM 
217 
ORGANIC MATERIAL 
218 
ORGANIC MATERIAL COMPOSTING 
219 
ORGANIC MATERIAL PROCESSING 
220 
PEAK 
221 
PILE 
222 
POULTRY LITTER 
223 
PUSHOUT OR CLEAR AREA 
224 
SHREDDED WOOD 
225 
SOLVITA® MATURITY INDEX 
226 
STOCKPILE 
227 
STOCKPILING OF SMALL ORGANIC MATERIAL 
228 
THROUGHPUT 
229 
WINDROW 
230 
WOOD CHIP 
SECTION 300 – STANDARDS 
301 
STOCKPILING REQUIREMENTS 
302 
ORGANIC MATERIAL COMPOSTING REQUIREMENTS 
303 
ORGANIC MATERIAL COMPOSTING CONTROL MEASURES 
304 
FIRE PREVENTION 
305 
BASIC TRAINING FOR ORGANIC MATERIAL PROCESSING OPERATIONS 
SECTION 400 – ADMINISTRATIVE REQUIREMENTS 
401 
COMPLIANCE SCHEDULE 
SECTION 500 – MONITORING AND RECORDS 
501 
RECORDKEEPING AND RECORDS RETENTION 
502 
STOCKPILING RECORDKEEPING 
503 
ORGANIC MATERIAL COMPOSTING RECORDKEEPING AND REPORTING 
504 
FIRE PREVENTION RECORDKEEPING AND REPORTING 
505 
TEST METHODS AND PROTOCOLS  
 
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Adopted XX/XX/XXXX 
MARICOPA COUNTY AIR POLLUTION CONTROL REGULATIONS 
REGULATION III – CONTROL OF AIR CONTAMINANTS 
RULE 327 (ORGANIC MATERIAL PROCESSING) 
SECTION 100 – GENERAL 
101 
PURPOSE:  
101.1 The purpose of this rule is to limit the emissions of volatile organic compounds 
(VOC) and ammonia from organic material processing operations and prevent 
emissions of fine particulate matter (PM2.5) and nitrogen oxides (NOx) from 
combustion of organic material processing operations. 
101.2 This rule is created as a contingency measure for the 2015 National Ambient Air 
Quality Standard (NAAQS) for ozone as required by Section 172(c)(9) of the Act. 
102 
APPLICABILITY:  
102.1 This rule applies to the owner or operator of all new and existing organic material 
processing operations that produce or receive 200 or more wet tons per year of 
any of the following, or a combination thereof: 
a. Green material; 
b. Food material; 
c. Less than or equal to 75 percent animal manure or poultry litter, by volume. 
102.2 The requirements of this rule shall become effective 180 days following a 
determination by the U.S. Environmental Protection Agency (EPA) that either of 
the following triggering events has occurred in a. or b.: 
a. The Phoenix-Mesa 2015 ozone NAAQS nonattainment area failed to attain the 
2015 ozone NAAQS by the Moderate area attainment date; 
b. The Phoenix-Mesa 2015 ozone NAAQS nonattainment area failed to make 
reasonable further progress under the 2015 ozone NAAQS. 
c. If EPA makes such a determination as described in §§ 102.2 a. or b. prior to 
adoption of this rule, the requirements of this rule shall become effective 180 
days following adoption.  
103 
EXEMPTIONS: The provisions of this rule shall not apply to the following: 
103.1 Organic material processing operations at any site owned, leased, operated, 
controlled, or supervised by the same owner or operator that satisfy all of the 
following conditions: 
a. All organic material processing is conducted on site; 
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b. All organic material processed on site is used on site; and 
c. No financial transaction occurs for receipt of organic material used in organic 
material processing. 
103.2 Backyard composting. 
103.3 Community composting. 
SECTION 200 – DEFINITIONS: For the purpose of this rule, the following definitions 
shall apply. See Rule 100-General Provisions and Definitions of the Maricopa County Air 
Pollution Control Regulations for definitions of terms that are used but not specifically defined 
in this rule. In the event of any inconsistency between any of the rules within the Maricopa 
County Air Pollution Control Regulations, the definitions in this rule take precedence.  
201 
ACTIVE PHASE: The phase of the composting process that begins when organic 
materials are mixed or piled together for composting and ends when the organic 
material has been composted for a period of 22 consecutive days or when any of the 
following conditions is met as measured by the applicable test method in § 505.2: 
201.1 The organic material respiration rate is no more than 20 milligrams of oxygen 
consumed per gram of volatile solids per day; or 
201.2 The organic material emits no more than seven mg carbon dioxide per gram of 
organic material (CO2 – C) per day; or 
201.3 The organic material has a Solvita® Maturity Index of five or greater. 
202 
AERATED STATIC PILE SYSTEM (ASP): A self-contained system that produces forced 
air via a motor or blower either in a positive direction towards one or more organic 
material piles or a negative direction towards a biofilter. 
203 
ANIMAL MANURE: Non-human animal excretions and waste, including, but not limited 
to, solids and urine from cows, cattle, or swine. 
204 
AUTHORITY HAVING JURISDICTION FOR FIRE PREVENTION AND LIFE SAFETY: An 
entity responsible for enforcing regulations, including but not limited to building or fire 
codes, in a given jurisdictional boundary. 
205 
BACKYARD COMPOSTING: Composting conducted by a household including, but not 
limited to, single family residences, condominiums, duplexes, or apartment buildings for 
noncommercial uses. 
206 
BIOFILTER: Any combination of finished compost, shredded wood, and wood chips, that 
is connected to an ASP and reduces VOCs from organic material compost pile 
emissions. 
207 
COMMUNITY COMPOSTING: Composting conducted by a residential neighborhood 
association using feedstock generated within the residential neighborhood to produce 
compost for the neighborhood’s use. 
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208 
COMPOST: A product resulting from the controlled biological decomposition of organic 
materials. 
209 
COMPOSTING: A process in which solid organic waste materials are decomposed in 
the presence of oxygen through the action of bacteria and other microorganisms. 
210 
CURING PHASE: The phase of the composting process that begins immediately after 
the active phase and ends when the organic material has been composted for a period 
of 40 consecutive days after the active phase, or when any of the following conditions is 
met as measured by the applicable test method in § 505.2: 
210.1 The organic material respiration rate is no more than 10 milligrams of oxygen 
consumed per gram of volatile solids per day; or 
210.2 The organic material emits no more than four mg carbon dioxide per gram of 
organic material (CO2-C) per day; or 
210.3 The organic material has a Solvita® Maturity Index of seven or greater.  
211 
FINISHED COMPOST: A humus-like material that has completed both the active phase 
and curing phase of composting. 
212 
FINISHED COMPOST COVER: Pre-screened finished compost, or a mixture of screened 
finished compost or overs, that is applied to a windrow or pile as a cover to reduce VOC 
emissions. 
213 
FOOD MATERIAL: Food scraps collected from the food processing industry, food 
service industry, grocery stores, or residential food scrap collection. Food material also 
includes food material that is chipped or ground. 
214 
GREEN MATERIAL: Vegetative material generated from gardening, agriculture, or 
landscaping activities including, but not limited to, a mixture of grass clippings, leaves, 
tree and shrub trimmings, and plant remains. 
215 
INDEPENDENT WATERING SYSTEM: a system connected to a water source that 
uniformly applies water by means of nozzles operated under pressure and may include, 
but is not limited to, portable sprinkler system, non-portable sprinkler system, or water 
truck. 
216 
INTEGRATED WATERING SYSTEM: a system connected to a water source that 
uniformly applies water by means of nozzles operated under pressure which are 
installed in front of or simultaneously with the mechanical turner blades. 
217 
ORGANIC MATERIAL: Food material, green material, animal manure, poultry litter, or 
any mixture thereof. 
218 
ORGANIC MATERIAL COMPOSTING: A process in which green material by itself, food 
material by itself, or a mixture of green material, food material, or up to 75 percent 
animal manure or poultry litter, by volume, are decomposed in the presence of oxygen 
through the action of bacteria and other microorganisms. 
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219 
ORGANIC MATERIAL PROCESSING: Organic material composting, stockpiling of small 
organic material, or any combination thereof. 
220 
PEAK: The highest point along the ridge of the pile. 
221 
PILE: Organic material that is heaped together. 
222 
POULTRY LITTER: Poultry excretions and waste, including, but not limited to, dried 
solids and urine from chickens, turkeys, geese, or ducks. 
223 
PUSHOUT OR CLEAR AREA: A designated area provided for temporary pile storage and 
to allow for the spreading of piles and to move unburned material away from a pile in 
the event of fire or hotspot within the pile. Water should be immediately available to aid 
in cooling. 
224 
SHREDDED WOOD: Any wood material or woodwaste that has been mechanically 
reduced in size to less than twelve inches in any dimension. 
225 
SOLVITA® MATURITY INDEX: an index that defines the stage where compost exhibits 
resistance to further decomposition, in accordance with the TMECC Method 05-08-E – 
Solvita® Maturity Test (April 7, 2002). 
226 
STOCKPILE: Organic material, which may or may not be chipped or ground, that is 
temporarily stored in a pile. 
227 
STOCKPILING OF SMALL ORGANIC MATERIAL: Storage of organic material less than 6 
inches in any dimension in a pile. 
228 
THROUGHPUT: The amount of organic material received. 
229 
WINDROW: Organic material that is placed in an elongated pile for organic material 
processing. 
230 
WOOD CHIP: Any wood material or woodwaste, less than 2 inches in any dimension. 
SECTION 300 – STANDARDS 
301 
STOCKPILING REQUIREMENTS: The owner or operator of an organic material 
processing operation shall comply with one of the following within 10 consecutive days 
of receipt of the organic material at the facility: 
301.1 Remove the organic material from the facility. 
301.2 Start the active phase of composting. 
301.3 Cover the organic material with a waterproof cover such that there is at least a 
six-foot overlap of adjacent covers and the cover is secured in place. 
301.4 Demonstration of compliance with § 304.3 a.(1) or maintenance of moisture 
content of less than 40% through a Moisture Test as described in § 304.3 b. or c., 
and including the following: 
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a. A demonstration must be measured at least once per calendar week. 
b. If compliance is not demonstrated through § 304.3 a.(1) or a Moisture Test 
as described in §§ 304.3 b. or c. demonstrates a moisture content of greater 
than 40% then the owner or operator shall implement one of the stockpiling 
requirements in §§ 301.1 through 301.3. 
302 
ORGANIC MATERIAL COMPOSTING REQUIREMENTS FOR ORGANIC MATERIAL 
COMPOSTING OPERATIONS THAT RECEIVE LESS THAN OR EQUAL TO 10,000 TONS 
PER YEAR OF ORGANIC MATERIAL: The owner or operator of an organic material 
composting operation with an organic material throughput of less than or equal to 
10,000 tons per year shall comply with all of the following during the active phase of 
composting: 
302.1 Apply water to each pile prior to turning pursuant one of the watering system 
control measures in § 304.1, unless the pile yields a compliant moisture test per 
§§ 304.3 a.(2), b., or c. within three hours prior to turning. 
302.2 Cover the piles with a finished compost cover upon initial pile formation as 
described in § 304.2. 
303 
ORGANIC MATERIAL COMPOSTING REQUIREMENTS FOR ORGANIC MATERIAL 
COMPOSTING OPERATIONS THAT RECEIVE GREATER THAN 10,000 TONS PER YEAR 
OF ORGANIC MATERIAL: The owner or operator of an organic material composting 
operation with an organic material throughput of greater than 10,000 tons per year shall 
comply with 303.1 or 303.2 during the active phase of composting: 
303.1 Application of Water and Finished Compost Cover: Implement all of the 
following: 
a. Apply water to each pile prior to turning pursuant one of the watering system 
control measures in § 304.1, unless the pile yields a compliant moisture test 
per §§ 304.3 a.(2), b., or c. within three hours prior to turning. 
b. Cover the piles with a finished compost cover upon initial pile formation and 
within three hours after each turning as described in § 304.2. 
303.2 Aerated Static Pile System (ASP): Operate and maintain the ASP in accordance 
with the manufacturer’s specifications or written procedures developed by the 
owner or operator based on good air pollution control practices for minimizing 
emissions, and comply with either of the following: 
a. Operate the ASP under continuous 24-hour negative pressure and vent 
emissions to a biofilter; or 
b. Operate the ASP under noncontinuous negative pressure and meet the 
following requirements: 
(1) Vent emissions to a biofilter, when operating under negative pressure; and 
(2) Upon initial pile formation cover the piles with a finished compost cover as 
described in § 304.2. 
304 
ORGANIC MATERIAL COMPOSTING CONTROL MEASURES 
304.1 Watering Systems 
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a. Independent Watering System 
(1) Apply water to the surface area of each pile prior to turning in order to 
yield a compliant moisture test.  
(a) A compliant moisture test for each pile must be demonstrated within 
three hours before turning.  
(b) A compliant moisture test shall be demonstrated as specified in §§ 
304.3 a.(2), b., or c. 
(2) If the pile does not yield a compliant moisture test, apply additional water 
to the pile until the pile yields a compliant moisture test prior to turning. 
b. Integrated Watering System 
(1) Mechanically turn the first pile while operating the integrated watering 
system. 
(a) A compliant moisture test for each pile must be demonstrated within 
three hours after turning. 
(b) A compliant moisture test shall be demonstrated as specified in §§ 
304.3 a.(2), b., or c. 
(2) If the pile does not yield a compliant moisture test, then perform the 
following: 
(a) Apply additional water and mechanically turn the same pile; 
(b) Retest for moisture until the pile yields a compliant moisture test.  
(c) Subsequent piles shall not be turned until the initial pile yields a 
compliant moisture test.   
c. Existing Moisture Compliance: For either the independent or integrated 
watering systems, a moisture test as specified in §§ 304.3 a.(2), b., or c. may 
be demonstrated within three hours prior to the turning of a pile. If the pile 
yields a compliant moisture test then water does not need to be added to the 
pile within three hours prior to the subsequent turn. 
304.2 Finished Compost Cover: An owner or operator shall cover the surface area of 
at least the top third of each pile with finished compost cover so that there is at 
least six inches in height of finished compost cover as measured at the peak of 
each pile. An owner or operator shall cover the surface area of each pile as 
described within three hours of initial pile formation and, as required in § 303.1 
b., within three hours after each turning of the pile for at least three turns of each 
pile. For any piles that are mechanically turned after 2:00 pm, an exception to the 
three-hour limit can be made, which allows the owner or operator to cover the 
surface area of at least the top third of each pile with finished compost cover 
within three hours of the start of organic material composting operations the 
following calendar day. 
304.3 Moisture Test: A compliant moisture test shall be demonstrated via the 
applicable Squeeze Ball Test or demonstrating a minimum 40% moisture content 
with ASTM Method D2216-05 or the Speedy Moisture Meter. 
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a. Squeeze Ball Test: The squeeze ball test shall be conducted by taking a 
sample of the compostable material from the top half of the pile, at least 
three inches below the outer surface. The material should be squeezed into a 
ball using hand pressure and wearing a protective glove.  
(1) Compliant Stockpiling Squeeze Ball Test: The organic material should be 
dry enough so that it does not form a ball under hand pressure, and does 
not continuously hold shape when hand compression is released. 
(2) Compliant Composting Squeeze Ball Test: There should be at least 
enough water to form a ball when compressed, but the ball may break 
when tapped. If the ball crumbles upon release of the hand pressure, apply 
additional water to the pile prior to turning until the material does not 
crumble upon release of hand pressure. 
b. ASTM Method D2216-05: Moisture testing shall be conducted in accordance 
with the requirements of ASTM Method D2216-05 ("Standard Test Method for 
Laboratory Determination of Water (Moisture) Content of Soil and Rock by 
Mass"). 
c. Speedy Moisture Meter: As an alternative to § 304.3 b. of this rule, the 
Speedy Moisture Meter may be used upon receiving written approval from the 
Control Officer and after submitting to the Control Officer a written request 
that includes the following information: 
(1) A description of the alternative testing equipment, including the display 
range, maintenance requirements, and any limitations; 
(2) A correlation analysis conducted using 20 samples from the Speedy 
Moisture Meter and the results using ASTM Method D2216-05. A separate 
correlation analysis shall be done for each unit (serial number shall be 
specified); 
(3) A description of the calibration procedures that includes the following 
information: 
(a) Calibration of each Speedy Moisture Meter (serial number shall be 
specified) on at least a biweekly basis against ASTM Method D2216-
05 as a standard; 
(b) Identification of at least three sampling points per pile to be used for 
calibration. The three sampling points shall be as distinctly separated 
as reasonably possible. 
(4) An agreement to revert to ASTM Method D2216-05 if the Speedy Moisture 
Meter results do not correlate with ASTM Method D2216-05. 
305 
FIRE PREVENTION: The owner or operator of an organic material processing operation 
shall submit to the Control Officer a Fire Prevention Plan approved by an authority 
having jurisdiction for fire prevention and life safety and comply with §§ 305.3 through 
305.5. An owner or operator of an organic material processing operation without an 
approved Fire Prevention Plan by an authority having jurisdiction for fire prevention and 
life safety shall comply with §§ 305.1 through 305.5: 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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305.1 Fire Department Access and Safety Equipment: 
a. Fire Department Access: The owner or operator shall ensure that the local 
fire department has access to the facility as follows: 
(1) The Fire Department shall have full 24/7 access to the facility through the 
use of a fire department keyed lock or through having the facility 
continually staffed 24 hours a day, 7 days a week. If the facility does not 
have a gate, it must be staffed 24 hours a day, 7 days a week. 
(2) Facility name, address, and 24-hour emergency contact telephone 
numbers shall be posted at the main entrance and main fire department 
entrance and clearly visible from the street. 
(3) Access roads at the facility must provide access to within 150 feet of all 
areas of the property so that a fire truck can drive close enough to deploy 
lines to fight a fire. 
(4) Access roads must be 20 feet wide and maintained so that in inclement 
weather fire trucks can drive on them. 
(5) Access roads shall be marked with signage. 
b. Fire Extinguishers: Portable fire extinguishers with a minimum rating of 4-A: 
60-B: C shall be provided on all vehicles and equipment operating on piles and 
at all processing equipment. 
c. Conveyor Systems: Conveyor systems carrying combustible materials and 
enclosed conveyor systems shall be equipped with an approved automatic 
sprinkler system. 
305.2 Pile Layout: 
a. Storage Site: Sites shall be level and on solid ground, elevated soil lifts or 
other all-weather surface. Sites shall be thoroughly cleaned before 
transferring organic material to the site. 
b. Pile Dimensions: Piles shall not exceed 25 feet (7.62 meters) in height, 150 
feet (45.72 meters) in width, and 250 feet (76.2 meters) in length unless 
approved by an authority having jurisdiction for fire prevention and life safety. 
c. Pile Separation: 
(1) Piles shall be separated from adjacent piles by fire apparatus access 
roads. 
(2) Pushout or clear areas shall be provided for temporary pile storage. 
(3) Any pile or row in place exceeding 30 days or over 100 cubic yards (76.5 
cubic meters) in size shall have a pushout or clear area. 
(4) The pushout or clear area(s) shall be located not more than 250 feet (76.2 
meters) from all pile(s) and shall not be located within 20 feet (6.096 
meters) of any building. 
(5) Water sufficient for fire suppression shall be made immediately available 
at all designated pushout or clear areas. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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(6) Pushout or clear areas shall be sized to hold no less than roughly a 
quarter of the size of the single largest pile or row it serves at a maximum 
depth of three feet. 
305.3 Regular Internal Temperature Monitoring 
a. Rows Only: The internal temperature of each row shall be measured using a 
compost thermometer or soil temperature probe, at a depth of three feet. 
Each row shall be temperature sampled every 50 horizontal feet or less along 
the length of the row, starting at the end with the least aged (most recently 
added) organic material, and at the heights and time intervals specified in § 
304.3.b. 
b. Piles and Rows: Internal temperature shall be taken at the following heights 
and time intervals: 
(1) Organic material piles or rows equal to or under 6 feet high: 
(a) Internal temperature samples shall be taken once every 7 calendar 
days and recorded as required in § 504. 
(b) Each pile or row shall be sampled between 3 and 4 feet from the 
bottom of the pile or row. 
(2) Organic material piles or rows more than 6 feet high: 
(a) Internal temperature samples shall be taken on every calendar day and 
recorded as required in § 504. 
(b) Each pile or row shall be sampled every 5 vertical feet starting from the 
bottom of the pile or row. No temperature sample need be taken at 
less than 2 feet from the top of the pile or row. 
c. Corrective Action: If any part of the pile or row being sampled for 
temperature is found to have an internal temperature of 160 °F (71 °C) or 
greater, immediate action must be taken to reduce the temperature. If at any 
time the temperature, at any location, is found to have an internal temperature 
of 180 °F (82 °C) or greater, the following procedures must immediately be 
performed: 
(1) The area with the high temperature shall be dug out of the main pile and 
the overheated organic material shall be pushed out into a designated 
pushout or clear area; 
(2) Water shall be stationed closely to the affected area, prior to digging out 
the hotspot to immediately douse any flare ups that may occur when air is 
added to overheated area; 
(3) Continual temperature probing and removal of organic material greater 
than 180 °F shall be conducted until all overheated material is separated 
into the pushout or clear area and the temperature is below 180 °F. 
305.4 Material-Handling Equipment: The owner or operator shall ensure material 
handling equipment to aid in the event of emergency is available on site or by 
contract. Equipment shall include: 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 43 of 68

a. Equipment to move stored organic material during fire; 
b. Water trucks; 
c. Water pumps if using pond for any piece of water source. 
305.5 Monitoring and Recordkeeping: The owner or operator shall monitor and 
perform recordkeeping as described in § 504 (Fire Prevention Recordkeeping and 
Reporting). 
306 
BASIC TRAINING FOR ORGANIC MATERIAL PROCESSING OPERATIONS: The owner or 
operator of an organic material processing operation shall provide training on the 
compliance requirements of § 300 to all organic material processing operations 
personnel upon initial hire.  
SECTION 400 – ADMINISTRATIVE REQUIREMENTS 
401 
COMPLIANCE SCHEDULE: Unless the EPA makes a determination as described in 
Section 102.2 after rule adoption, the provisions of the rule shall become effective 180 
days after the adoption date of the rule. 
SECTION 500 – MONITORING AND RECORDS 
501 
RECORDKEEPING AND RECORDS RETENTION: An owner or operator of an organic 
material processing operation shall comply with the following requirements set forth in 
this section. Any records and data required by this section shall be kept on site at all 
times in a consistent and complete manner. 
501.1 Records shall be retained for a period of five years. 
501.2 Records shall be made available to the Control Officer upon written request, no 
later than five business days after the request. 
501.3 Records shall be made available to the Control Officer upon request by members 
of the public using the County’s public records request process. 
502 
STOCKPILE RECORDKEEPING: An owner or operator of an organic material processing 
operation shall maintain and report the following stockpiling records: 
502.1 The date of which each stockpile was initially formed; 
502.2 The date and action taken on each stockpile to satisfy the stockpile requirements 
in § 301; and 
502.3 Other information necessary to determine compliance with the requirements. 
503 
ORGANIC MATERIAL COMPOSTING RECORDKEEPING AND REPORTING: An owner or 
operator of an organic material composting operation shall maintain and report the 
following composting records: 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 44 of 68

503.1 Organic Material Throughput: 
a. Record the organic material throughput each month by the end of the 
following month.  
b. Record a 12-month rolling average annual throughput. The 12-month rolling 
average may exclude any non-putrescible materials, including, but not limited 
to paper, woody, other low-water, high cellulose materials, and non-
compostable contaminants and green waste that are separated either before 
or after composting and shipped off-site for disposal provided they are 
quantified and appropriate records are maintained. 
503.2 Organic Material Composting Operations Records: Record the date and time for 
each of the following: 
a. When each pile was initially formed for the active phase and when finished 
compost cover, which satisfied the minimum six inches finished compost 
cover requirement, was applied to each pile. 
b. When the organic material from each pile was tested for compliance with the 
moisture test prior to turning. Indicate whether each pile passes the moisture 
test and, if applicable, all corrective actions taken. 
c. When each pile was turned. 
d. Record other information necessary to determine compliance with the 
requirements. 
503.3 ASP Operation Records:  
a. Record the date and time when the ASP is operating under negative pressure. 
b. Record the date and time the biofilter media is replaced. 
c. Record the date, time, and pressure drop of the duct system vented to the 
biofilter, at least once per week. 
d. Maintain a copy of the manufacturer’s specifications or written procedures 
developed by the owner or operator based on good air pollution control 
practices for minimizing emissions, used to comply with § 303.2, on site and 
available to the Control Officer upon request. 
503.4 Organic Material Composting Training Records: Records that demonstrate 
training requirements were provided to all organic material composting 
operations personnel that perform duties related to compliance with 
requirements of § 300. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 45 of 68

504 
FIRE PREVENTION RECORDKEEPING AND REPORTING: An owner or operator of an 
organic material processing operation shall maintain and report the following fire 
prevention records: 
504.1 Internal Temperature Sample Log: A written or electronic record of internal pile 
or row internal temperature sample(s). 
504.2 Smoldering and/or Smoke Self-Inspection Log: A written or electronic record of 
self-inspection that includes an inspection of the entire facility for signs of 
smoldering or smoke conducted twice daily. 
504.3 Fire Report: Submit a quarterly report to the Control Officer within 30 days after 
the end of each quarterly time period. Upon four successive quarterly fire reports 
which include zero incidents of fire, the fire report may be submitted on an 
annual basis. Annual fire reports shall be submitted before January 31 of each 
year. Upon the occurrence of a subsequent fire incident, the fire report shall be 
submitted quarterly until four more successive fire reports of zero fire incidents. 
The report shall include the following: 
a. The time and day that a fire occurred. 
b. Explanation of the incident and suspected cause. If the cause is unknown, the 
report shall indicate that the cause is unknown. 
c. The corrective action taken. If no corrective action was taken, the report shall 
indicate that no corrective action was taken. 
505 
TEST METHODS AND PROTOCOLS: The following test methods are approved for use 
for the purpose of determining compliance with this rule. Other EPA-approved test 
methods may be used upon prior written approval from the Control Officer.  
505.1 Compliance Determination for Moisture Test Methods Incorporated by 
Reference: ASTM Method D2216-05 ("Standard Test Method for Laboratory 
Determination of Water (Moisture) Content of Soil and Rock by Mass"), 2005 
edition. 
505.2 Compliance Determination for Compost Maturity/Stability Test Methods 
Incorporated by Reference: 
a. TMECC Method 05-08-A – Specific Oxygen Uptake Rate (April 7, 2002); 
b. TMECC Method 05-08-B – Carbon Dioxide Evolution Rate (April 7, 2002); 
c. TMECC Method 05-08-E – Solvita® Maturity Test (April 7, 2002). 
505.3 Multiple Test Methods: When more than one test method or set of test methods 
is specified for testing, failure to comply with a requirement of this rule 
established by one of the specified test methods or set of test methods shall 
constitute noncompliance with this rule. 
 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 46 of 68

NOTICE OF ACCOMMODATIONS: Individuals with disabilities. Assistive listening devices, large-printed materials, special parking 
arrangements, and other accommodations are available with 72 hours advance notice. If you require accommodations to participate 
in the above meeting, please contact Nicole Harden (PHS) at (480) 271-8374.    
1 
BOARD OF HEALTH MEETING MINUTES 
April 22, 2024 | 3:00-5:00 pm 
4041 N. Central Avenue, 14th Floor, Phoenix, AZ 
Legal Advice - A.R.S. §38-431.03(A)(3) 
The Board may vote to go into Executive Session for the purpose of discussion or consultation for legal advice with the attorney or 
attorneys of the Board on any matter listed on the agenda pursuant to A.R.S. §38-431.03 (A)(3). Board of Health members will attend 
in person or by telephone conference call. Members attending telephonically will be announced at the meeting. Agendas are available 
within 24 hours of each meeting in the Public Health Administration office at 4041 N. Central Ave., 14th floor, Monday through Friday 
between 8:00 a.m. and 5:00 p.m. 
ITEM 
TOPIC/ACTION 
TYPE 
PRESENTER 
1. 
Call to Order: The meeting was called to order at 3:08 pm. 
A. Roll Call 
Members Present: Supervisor Bill Gates, Cynthia Hardy, Robert 
MacMillan, Veronica Oros, Joanne Osborne, Mary Schraven, 
Stefanie Schroeder 
Members Absent: Debra Baldauff, Matthew Farber, Lorenzo 
Sierra 
•
A quorum of (6) members was confirmed.
B.    Call to the public: Unite Here, Local 11 Union, representative 
Jordan Greenslade, spoke to inform the Board of Health of a 
potential compliance issue with Maricopa County Environmental 
Health Code regulations by SSP America. 
Blanca Caballero, Environmental Services Executive Director, met 
with all representatives from Unite Here to set up a meeting. 
Action 
President 
Osborne 
2. 
Approval of Minutes 
President Osborne asked the Board for a motion to approve the 
January 22, 2024 minutes. 
Motion: Robert MacMillan 
Second: Stefanie Schroder 
Motion status: Approved unanimously 
Action 
President 
Osborne 
Return to list of attachments
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 47 of 68

2 
 
 
NOTICE OF ACCOMMODATIONS: Individuals with disabilities. Assistive listening devices, large-printed materials, special parking 
arrangements, and other accommodations are available with 72 hours advance notice. If you require accommodations to participate 
in the above meeting, please contact Nicole Harden (PHS) at (480) 281-8374. 
3. 
Appointment of Dr. Stefanie Schroeder 
 
Overview: Jeanene Fowler introduced and read Stefanie’s bio. 
• 
Graduated from Medical school in 1990 
• 
Board Certified in Emergency Medicine 
• 
10 years as a Physician at Banner Baywood Medical Center 
• 
16 years as ASU Chief of Medical Staff 
Discuss 
Jeanene Fowler 
4. 
Public Health Finance 
 
Make a recommendation to the Board of Supervisors to approve the 
Public Health Fiscal Year 2025 budget request as recommended by 
the Maricopa County Budget Office. 
 
• 
Ms. Osborne requested clarification on the Special Revenue 
Fee Fund. Jeanene explained the process to which Public 
Health bills health plans for vaccinations and that often it 
can take upwards of a year to receive reimbursement. Next 
year’s budget is the best projection on how much we may be 
reimbursed based on historical billing.  
• 
Ms. Schroder asked for clarification on “ARPA.” Jeanene 
explained these are American Recue Plan Funds used for 
projects related to the pandemic.  
• 
Ms. Osborne mentioned ARPA Fund needing to be used for 
hiring. Jeanene confirmed the ARPA fund will end December 
2026, but no jobs lost because of it. 
 
Motion: Stefanie Schroder 
Second: Mary Schraven 
Motion status: Approved unanimously 
Discuss/
Action 
Ray Farrish 
5. 
Environmental Services Finance 
 
Make a recommendation to the Board of Supervisors to approve the 
Environmental Services Fiscal Year 2025 budget request as 
recommended by the Maricopa County Budget Office 
 
• 
Ms. Donaldson called out a change to Fund 100 (since 
budget letter was sent out to Board) – Expenditures dropped 
from $13,523,785 to $10,897,837 due to risk management 
lowering the assessment for the closed landfills Maricopa 
County has. 
• 
Ms. Osborne asked for clarification on Fund 100. Ms. 
Donaldson clarified $463,100 is all revenue from multiple 
sources and then allocated out. $10,897,837 is spending 
authority.  
Discuss/
Action 
Sylvie 
Donaldson 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 48 of 68

3 
 
 
NOTICE OF ACCOMMODATIONS: Individuals with disabilities. Assistive listening devices, large-printed materials, special parking 
arrangements, and other accommodations are available with 72 hours advance notice. If you require accommodations to participate 
in the above meeting, please contact Nicole Harden (PHS) at (480) 281-8374. 
• 
Fund 290: Mr. MacMillan commented on current state of tire 
sales. Ms. Donaldson stated tire sales are expected to 
increase. There is a delayed revenue on tire sales. Won’t 
come until following year. 
• 
Fund 506: Ms. Donaldson stated the entire budget is 
reflected in the $26,317,620 that includes an increase of 
county wide allocations that have gone up and assessments 
from Central Services Cost Allocation. 
 
Motion: Robert MacMillan 
Second: Mary Schraven 
Motion status: Approved unanimously 
6. 
Environmental Services Dept. Fee Waiver Applications  
 
Request for Board of Health approval of Twenty-three (23) fee 
waiver applicants – P1-P22 & C1 
 
• 
Ms. Osborne asked what the fee for Valley Life was for. 
Supervisor Gates confirmed that the Fee Waiver for Valley 
Life are start up fees for a new location. 
 
Motion: Mary Schraven 
Second: Stefanie Schroder 
Motion status: Approved unanimously 
Discuss/
Action 
Robert 
Stratman 
7. 
Air Quality Department   
Approve initiation of regulatory change for the following rule: 
 
A. AQ-2023-005 
Rule 327 (Organic Material Processing) 
 
The Maricopa County Air Quality Department (MCAQD) is proposing 
to create Rule 327 to limit the emissions of volatile organic 
compounds (VOCs) and ammonia from organic material processing 
operations and prevent emissions of fine particulate matter (PM2.5) 
and nitrogen oxides (NOx) from combustion of organic material 
processing operations. 
 
• 
Mr. MacMillan asked if EPA is requiring this rule. Mr. 
Verkamp stated they are seeking approval to begin the 
process of revising the rule to gain more reductions of 
ozone precursors. They are reviewing all kinds of measures 
of hosting. Organic material processing is just one area to 
comply with the National Ambient Air Quality. 
Discuss/
Action 
Gregory 
Verkamp 
Kimberly Butler 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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4 
 
 
NOTICE OF ACCOMMODATIONS: Individuals with disabilities. Assistive listening devices, large-printed materials, special parking 
arrangements, and other accommodations are available with 72 hours advance notice. If you require accommodations to participate 
in the above meeting, please contact Nicole Harden (PHS) at (480) 281-8374. 
• 
This rule will limit the emissions of volatile organic 
compounds along with ammonia from organic material 
processing operations and prevent emissions of fine particle 
matter and nitrogen oxides as well. 
• 
Stakeholder workshop has been held March 2024. Feedback 
was received and meetings have been held to get process in 
motion. Plans are to have another Stakeholder workshop. 
• 
Exemptions that will be built into the rule: 
- Farmers who use manure for composting and not selling it  
- Residential neighborhoods gardening that are doing 
composting  
- There will be an applicability level built into the rule for  
businesses that are selling compost  
• 
The rule will also include permitting thresholds – 
example would be if a business emits a certain amount 
of a particular pollution. 
• 
Rule will help reduce emissions by 60-70%. Reduction will 
continue as industry grows. 
• 
Rule will only affect large businesses. No residential areas 
will be affected. 
• 
Mr. MacMillan asked what the cost benefit would be. Ms. 
Butler stated the Cost benefit has not been completed at 
this time. It is estimated that there will be minimal cost to 
the businesses verses 100’s of tons per year saved in VOC 
emissions. Seeking to put fire management systems into 
place as well as part of this rule.  
• 
Ms. Osborne asked if businesses would incur new fees 
because of the new rule. Mr. Verkamp & Ms. Butler shared 
that they are seeking to make it a general permit to avoid 
additional new fees. Many businesses already have the Dust 
Prevention Permit. Still working with the Permit group. This 
would add provisions into an existing permit – 
approximately $350/year.  
• 
Ms. Osborne asked if a business does have a fire, would 
they get fined. Ms. Butler responded should a business have 
a fire/situation, each incident is looked at individually and 
reviewed under same permit. All paperwork is under same 
Dust permit.  
• 
Ms. Osborne asked how many fires a year do we see from 
this happening. Ms. Butler stated there is approximately one 
major fire from composting every 18 months but cannot 
state for sure. 
• 
Ms. Osborne asked how many businesses this will affect. 
Ms. Butler stated as of right now the number of businesses 
affected is still unknown as it is too early to tell.  
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
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5 
 
 
NOTICE OF ACCOMMODATIONS: Individuals with disabilities. Assistive listening devices, large-printed materials, special parking 
arrangements, and other accommodations are available with 72 hours advance notice. If you require accommodations to participate 
in the above meeting, please contact Nicole Harden (PHS) at (480) 281-8374. 
• 
Ms. Osborne asked if Air Quality will be reaching out to the 
Stakeholders. Mr. Verkamp stated, yes. They have sent out 
emails to create a contact list. They reach out to the 
stakeholders at each step of their process. They have one-
on-one meetings with them all the time to figure out proper 
language, what is working and what isn’t. 
• 
Ms. Osborne asked for an example of what this rule affects 
and how it will help. Ms. Butler responded that this rule will 
directly affect the moderate ozone nonattainment we are 
currently in. Within the next approximate year, we could 
potentially be in serious nonattainment ozone. It will help 
reduce precursors which in turn will help reduce the ozone. 
 
Motion: Robert MacMillan 
Second: Stefanie Schroder 
Motion status: Approved unanimously 
 
B. AQ-2024-002 
Rule 335 (Architectural Coatings) 
 
MCAQD is proposing to revise Rule 335 to assist towards 
attainment of the ozone National Ambient Air Quality Standards by 
lowering many of the architectural coating VOC content limitations 
in the rule and adding additional coating VOC content limitations to 
the rule to reflect standards in the Ozone Transport Commission 
Model Rule “Architectural and Industrial Maintenance (AIM) 
Coatings”. 
 
• 
Seeking emission reductions of volatile organic compounds 
that lead to the creation of ozone. 
• 
Seeking to lower VOC content limitations in the rule and to 
add additional VOC content limitations to the rule based off 
the Ozone Transport Commission Model Rule. 
• 
Ms. Osborne asked what government level holds the Ozone 
Transport Commission Model Rule. Mr. Verkamp stated it is 
an organization created by the EPA to address ozone issues 
in Northeast Ohio and other small eastern states. They have 
already created rules that other parts of the country have 
used. AQD would like to incorporate these standards into 
other rule proposals. 
• 
Ms. Osborne asked for clarification on what ‘Architectural 
Coating’ is. Mr. Verkamp confirmed it is paint. The strategy 
of the rule is to go to paint manufacturers and require them 
to change their blends, so the vault organic compound 
content meets the rule. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 51 of 68

6 
 
 
NOTICE OF ACCOMMODATIONS: Individuals with disabilities. Assistive listening devices, large-printed materials, special parking 
arrangements, and other accommodations are available with 72 hours advance notice. If you require accommodations to participate 
in the above meeting, please contact Nicole Harden (PHS) at (480) 281-8374. 
• 
Ms. Osborne asked if such a product is already available or 
would this rule cause a problem or cause an increase in the 
product. Mr. Verkamp responded to say they are currently 
looking into it by working with consultants to gauge what is 
currently being sold in stores and to ensure they are meeting 
OTC standards. 
• 
Mr. Verkamp stated if rule is adopted, it would give 
manufacturers and sellers a year to come into compliance 
by changing blends, labels, etc. 
• 
Ms. Osborne asked if any paint manufacturers are local. Mr. 
Verkamp stated they are reaching to the American Coding 
Association, who represents the businesses that attended 
the workshop.  
 
Motion: Mary Schraven 
Second: Stefanie Schroder 
Motion status: Approved unanimously 
 
Air Quality Department   
Approve expedited process rulemaking for the following rule: 
 
C. AQ-2024-003  
Ordinance P-21 (Vehicle Idling Restriction) 
 
MCAQD is proposing to revise Ordinance P-21 to add provisions to 
require all persons currently required to complete basic or 
comprehensive dust control training to complete idle reduction 
training. The training will be incorporated into existing training 
programs that operators are already required to complete due to 
fugitive dust training requirements in Rule 310 (Fugitive Dust from 
Dust-Generating Operations) and Rule 316 (Nonmetallic Mineral 
Processing). 
 
• 
Proposing to require those who already take the Dust 
Control Training to also take an Idle Reduction Training.  
• 
This only calls for additional slides to be added to the 
current PowerPoint presentation training slide deck for Dust 
Control Training.  
• 
Ms. Osborne asked if public transportation is involved. Mr. 
Verkamp confirmed this does not include public 
transportation, only for heavy equipment vehicles. 
 
Motion: Robert MacMillan 
Second: Stefanie Schroder 
Motion status: Approved unanimously 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 52 of 68

7 
 
 
NOTICE OF ACCOMMODATIONS: Individuals with disabilities. Assistive listening devices, large-printed materials, special parking 
arrangements, and other accommodations are available with 72 hours advance notice. If you require accommodations to participate 
in the above meeting, please contact Nicole Harden (PHS) at (480) 281-8374. 
8. 
Air Quality Department   
 
Revisions to Air Quality Enhanced Regulatory Outreach Program 
Process Flow Charts 
• 
Ms. Osborne asked if any points in time are being taken 
away from the public. Mr. Verkamp stated they over 90 
days and can provide input until taken to the Board of 
Supervisors. They are also allowed to attend the 
workshop as well. 
• 
Mr. MacMillan suggested to add in an email verification 
step of the EROP process informing businesses and 
stakeholders of an upcoming change to a rule to keep 
them more informed. 
Discuss 
Gregory 
Verkamp 
Kimberly Butler 
9. 
Maricopa County Department of Public Health 
 
Heat Relief Update (PPT Presentation) 
 
• 
Goal 1 is to secure appropriate transportation and call 
center support utilizing existing Promotora Program that 
also provide call center services through Solari 211 
• 
Goal 2 is to increase awareness with signage for heat relief 
locations 
• 
Goal 3 is to expand cooling center hours. Seeking to have a 
minimum of one cooling/respite center open until 7pm 
• 
The question was posed what the transportation is going to 
look like. Ms. Fowler responded that there is a contract with 
Lyft, which is plan A. Working with Solari for a plan B. 
• 
Ms. Osborne asked if Opioid settlement funds can be used 
for the cooling and respite centers. Ms. Fowler stated they 
will be using the opioid settlements funds by putting 
naloxone at all cooling centers. 
• 
Please see presentation for additional information 
Discuss 
Jeanene Fowler 
10. 
 
Adjournment:  
• 
Ms. Osborne requested an agenda item be added to the next 
meeting to add an Executive Committee 
• 
The meeting adjourned at 4:53 pm 
• 
Motion to adjourn: Mary Schraven 
• 
Second: Stefanie Schroder 
• 
Motion status: Approved unanimously 
 
Action 
President 
Osborne 
 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 53 of 68

Sent: Wednesday, September 6, 2023 10:29 PM
To: PND Regulatory <PNDRegulatory@maricopa.gov>; Kathy Semder (HSD)
<Kathy.Semder@Maricopa.Gov>; Andy Linton (ENV) <Andy.Linton@Maricopa.Gov>; Bill Leal (DOT)
<Bill.Leal@Maricopa.Gov>; Kathryn Garcia (PND) <Kathryn.Garcia@Maricopa.Gov>; Blanca Caballero
(ENV) <Blanca.Caballero@Maricopa.gov>; Michele Ross (COA) <Michele.Ross@maricopa.gov>
Subject: Online Form Submittal: Citizen Comments
Citizen Comments
Each Regulatory Department is committed to providing opportunities for
stakeholder input regarding the adoption and amendment of all regulatory
requirements. Your input will be collected and forwarded to the appropriate
department. You will receive a written response from the applicable department
within two business days. We appreciate your comments and your time.
Case Number/Rule
AQ-2023-005-Rule 327 (Organic Material Composting)
Department
Environmental Services
I would like to
Other
First Name
Patrice
Last Name
Whalen
Organization
AAEC South Mountain High School
City
Phoenix
Zip
85042
Email
pwhalen@aaechs.com
Phone Number
602-323-9890
Phone Type
Work
Would you like someone to
contact you?
Yes
Comments
I am a teacher and looking for someone to come to my school to
explain Aquaponics through vector control
If applicable, attach
supporting documentation
associated with your
Field not completed.
Copies of all written and electronic Stakeholder input
Return to Stakeholder #1: Comment #1
Return to list of attachments
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 54 of 68

comment. The only file
types supported are MS
Office and Adobe Acrobat.
 
Email not displaying correctly? View it in your browser.
 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 55 of 68

This Message Is From an External Sender
This message came from outside your organization. Please use caution when corresponding outside the
county.
ZjQcmQRYFpfptBannerEnd
Citizen Comments
Each Regulatory Department is committed to providing opportunities for
stakeholder input regarding the adoption and amendment of all regulatory
requirements. Your input will be collected and forwarded to the appropriate
department. You will receive a written response from the applicable department
within two business days. We appreciate your comments and your time.
Case Number/Rule
AQ-2023-005-Rule 327 (Organic Material Processing)
Department
Environmental Services
I would like to
Express opposition
First Name
Zachary
Last Name
Brooks
Organization
Arizona Worm Farm
City
Phoenix
Zip
85020
Email
zach@zbrooks.com
Phone Number
6024186704
Phone Type
Mobile
Would you like someone to
contact you?
Field not completed.
Comments
I have provided a series of specific comments on the proposed
rules. However, I would like to express opposition (and, frankly,
dismay) over this rule. This will have the impact of either
reducing the amount of compost my farm is able to reduce or
dramatically increasing the amount of fossil fuel I have to burn to
comply with the rules. Princeton University's Project Drawdown
reports "that composting organic waste versus landfilling it can
reduce more than 50% of carbon dioxide-equivalent greenhouse
Return to Stakeholder #2: Comments #2 through #11
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 56 of 68

gas emissions", but the emission savings from landfill diversion is
only one benefit of composting.
What is not as talked about nor accounted for in the analysis on
composting by Project Drawdown, is the benefit of applying
compost to soil. When the end-use of compost is considered,
composting is indirectly tied to a dozen or more solutions
presented in Project Drawdown from green roofs and
conservation agriculture, to plant-based diets.
Compost is a natural way to provide nutrients to plants to
enhance productivity while storing carbon in soils. As such,
compost not only reduces carbon emissions by the
aforementioned amount, but shares emissions savings through
many of the other climate solutions in Project Drawdown by
acting as a carbon sink or “sponge” that can soak up emissions
currently in the atmosphere and limit the impacts of climate
change which is already causing devastating wildfires, flooding,
and droughts to name a few. 
A regulation which reduces composting or, even worse, requires
the extensive use of fossil fuel, is counter-productive.
The science this rule is based on is decades old and not
rigorous. The net impact is highly likely to be to release more
Methane gas and do much more harm than good.
If applicable, attach
supporting documentation
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Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 57 of 68

Rule 327 Comments and Issues 
 
Overall: This rule is based on measurements and assessments that are almost 20 years old and not 
widely replicated.  They seek to manage primarily CO2 emissions.  Two important points: First, the 
overall greenhouse gases released from food and green waste are at least 50% lower from composting 
than from burying that waste in a landfill.  If this rule has the effect of reducing composting, the impact 
on the overall quality of air in Maricopa County gets worse.  Second, many of the rules will require 
significantly more “loader time” to make compost.  My loaders burn diesel fuel – so a rule that requires 6 
hours of loader time per windrow per turn, will burn approximately 40 gallons of fossil fuel.  The EPA 
reports that every gallon of diesel fuel burned creates about 8,887 grams of CO2 or almost 36 Kilos of 
CO2 (based on CA study California Air Resources Board).  They estimated of process emissions from 
composting are 0.007 MTCO2/ton (7 KG per ton) or between 300 – 400 KG per row (of which the target 
is 50% - 60% reduction).  The rule is asking us to spend significant cost and 36 KG of CO2 to save 150 KG, 
which seems inefficient. 
Plus, the reduction ignores the widely accepted recognition of the following benefits from the USE of 
compost: 
• 
Decreased water use for similar growing results 
• 
Decreased Soil Erosion  
• 
Reduced Fertilizer Use  
• 
Reduced Herbicide Use  
102 Applicability: This rule applies to very small operations.  An operation processing 201 tons is 
going to product about 70 -90 yards of compost.  This will force very small operations to comply with 
complex rules and reporting regulations.  We recommend this be revised to operations larger than 10 
acres or that the rule be bifurcated into rules for large commercial operations (10 acres or larger) and 
small operations. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 58 of 68

301.3 Cover: This rule seems aimed at an environment where rain is a concern.  The average number 
of rainy days in Phoenix is 33.  This rule asks us to perform a rather difficult task 100% of the time, when 
it is only relevant less 10% of time.  We recommend this be replaced with “cover only material that will 
begin active composting if hydrated, prior to and during a predicted rain event” 
 
302.1 b. Composting Requirement: This rule restricts my ability to manage my piles based on 
my expert experience and consultants.  We frequently turn piles at day 4.  And, while rare, we 
occasionally do not turn pile more than twice. 
 
302.1 c. Composting Requirement: Adding six inches of finished compost after every turn is 
impractical with our footprint.  Our windrows are set far enough apart for a tractor with a turner, but not 
far enough apart for a loader to apply the finished compost after each turn.  We could add the finished 
compost when the row was initially established, but on subsequent turns.  We estimate the cost of this 
rule to be $4.61 per yard of compost (incremental cost). 
 
303.2  Composting Requirement: Again, adding six inches of finished compost after every turn 
is impractical with our footprint.  Our windrows are set far enough apart for a tractor with a turner, but 
not far enough apart for a loader to apply the finished compost after each turn.  We could add the 
finished compost when the row was initially established, but on subsequent turns.  We estimate the cost 
of this rule to be $4.61 per yard of compost (incremental cost). 
304.2 Pile Layout: It is not clear if this applies just to inputs or to compost as well.  It should not 
apply to active compost piles – if they meet the hydration requirements, it is impossible for them to 
catch fire.  The other requirements are covered by the rules for a Fire Prevention Plan – they are site 
specific and should be reviewed as such. 
501.3 Records: This one makes me very nervous.  I can’t see how my proprietary logs should be 
made available to the general public. 
502 Records: Much of our stockpile feedstock comes in a continuous flow (we get daily drops from 
various suppliers).  We don’t have the manpower or processes to record each delivery and the stockpiles 
are not discrete entities – we are actively receiving and using the material.  This should be re-written to 
reflect how these processes actually work. 
 
 
 
 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 59 of 68

Each Regulatory Department is committed to providing opportunities for
stakeholder input regarding the adoption and amendment of all regulatory
requirements. Your input will be collected and forwarded to the appropriate
department. You will receive a written response from the applicable department
within two business days. We appreciate your comments and your time.
Case Number/Rule
AQ-2023-005-Rule 327 (Organic Material Processing)
Department
Air Quality
I would like to
Other
First Name
Stacy
Last Name
Hettmansperger
Organization
City of Phoenix Public Works Department
City
Phoenix
Zip
85003
Email
stacy.hettmansperger@phoenix.gov
Phone Number
602-495-2496
Phone Type
Work
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contact you?
Yes
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Citizen Comments
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 60 of 68

August 2, 2024 
To: Maricopa County Air Quality Department 
Re: Maricopa County Proposed Rule 327 Request for Comments 
Dear Maricopa County Air Quality Department, 
The City of Phoenix values protecting human health and the environment in our services and operations, 
including composting. We welcome regulations that support optimal composting operations while 
reducing emissions. With these goals in mind, the City of Phoenix Public Works Department has the 
following comments related to Maricopa County’s Rule 327.  
202 Alternative Mitigation Measure: Please clarify what the expectation is for demonstrating reduction 
in VOC.  If source testing is required to demonstrate the reduction of VOCs, that would be cost 
prohibitive to the composting industry in Maricopa County resulting in increased landfilling of organics 
rather than production of nutrient rich compost.  
301 – 301.4 Stockpiling: The City agrees that inbound material should be processed as soon as possible 
and that stockpiles need to be effectively managed to reduce the risk of fire. If the stockpiles of green 
material are managed in compliance with fire code requirements, the risk of fire and odors can be 
reduced. There are operational conditions that may require unground and ground green material be 
stockpiled longer than 10 days including stockpiling feedstock for optimal biofilter media production and 
biofilter replacement (porous woody waste and logs), seasonal increases in inbound green material 
volumes including from monsoon storms, and equipment downtimes. Optimal feedstock and size of the 
biofilter media is essential for the biofilter’s optimal lifespan and operation of negative aeration in 
advanced compost technology systems. Depending on the size of the biofilter, it takes time to 
accumulate the necessary volume of the specific green materials needed for the biofilter replacement. If 
there are restrictions on stockpiling biofilter media, aerated pile facilities may be restricted to operate 
only positive aeration which is not always optimal to maintain ideal composting temperatures. 
Additionally, facilities may need to consider landfilling some of the inbound green material or using as 
alternative daily cover, resulting in increased emissions with transportation and landfilling compared to 
composting.  
Section 301.3 states, “Cover the organic material with a waterproof cover,” if the unground and ground 
green material stockpiles are covered for extended periods of time. If the waterproof cover is secured 
Return to Stakeholder #3: Comments #12 through #23
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 61 of 68

around the pile, restricting airflow and oxygen in the pile, there is a risk of creating anaerobic conditions 
and increased temperatures of the piles, resulting in associated odors and fire risk.  
We recommend updating the stockpiling requirements to focus on the facility’s demonstrated 
management and monitoring of the green material stockpiles instead of imposing a 10-day limit. The 
City supports consecutive day limits on food waste stockpiling for odor control.  
302.1 b and c Organic Material Composting Requirements:  
b. A minimum of five consecutive days apart for each turning of the pile may not always be optimal due 
to operations and environmental conditions. Maybe consider regulating the minimum turns required for 
active composting or provide a range in the number of days between each turn.  
c. Please see comment on section 303.2. If a six-inch finished compost cover is required, it should be 
limited to the first zone or pile in active composting only. Requiring biocover application with each turn 
of piles or zones in active composting would significantly reduce the processing capacity of the facility 
and increase operational costs.  
Applying a six-inch biocover in the first zone or pile of active composting only should also be sufficient to 
control VOCs. During the 2023 United States Composting Council Conference session on Research to 
Improve Compost Facility Air Emissions Permitting, Engineered Compost Systems staff presented that 
VOCs are the highest within the first five days of the active composting process and then drop off 
significantly for the duration of the active composting process.  
302.2 Implement a Control Officer and EPA approved alternative mitigation measure that 
demonstrates at least a 60% reduction, by weight, in VOC emissions.  
Can the standard be clarified as to the basis of the 60% reduction?   
303.1 Watering Systems: This section of the rule is excessively detailed as to the watering methods. 
Recommend simplifying this section that 40% moisture should be maintained and demonstrated with a 
compliant moisture test conducted as described in 303.3 before each turn.  
303.2 Finished Compost Cover: Researchers at Washington State University (WSU) and at Engineered 
Compost System have air emissions data that indicate that surface irrigation can be at least as effective 
as applying a biocover to reducing VOC emissions from positively aerated piles. WSU will be conducting 
another round of compost air emissions trials later this year to further test the validity of the existing 
data sets. The work is funded by the Washington State Department of Ecology.  It is recommended to 
wait for the results of this research before requiring the application of a finished compost cover in this 
rule.  Please also see comment on section 302.1 c. 
303.3 Compliant Moisture Test: The methods listed as a and b are the most common field tests for 
moisture levels.  Maintaining at least 40% moisture is important during active composting, but moisture 
levels can temporarily adjust when the piles are ready for screening to reduce clogging within the 
screen. It is recommended that that the 40% moisture requirement is specific to the active composting 
and curing phases. If moisture levels reduce for screening, water needs to be applied around the 
screening process to prevent opacity and fire risk.  
Section 500: Monitoring and Records 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 62 of 68

Will there be templates or assistance provided by Maricopa County on the required monitoring and 
records to ensure compliance prior to official implementation of this new rule?  
502 Stockpiling Recordkeeping: Please see comments on 301-301.4 
503.2 Organic Material Composting Operations Records: Please see comments on 302.1 b and c, and 
303.2. 
503.3 Alternative Mitigation Measure Records: Please see comments on 202 and 302.2.  
504.2 Smoldering and/or Smoke Self-Inspection Log: The twice daily requirement seems excessive. It is 
recommended that the requirement be daily. Please clarify that this log would need to be maintained 
daily and only presented upon inspection or at the request of Maricopa County. 
 
Sincerely, 
 
Pat Tapia 
Assistant Public Works Director 
 
 
City of Phoenix Public Works Department 
200 W. Washington St. 7th Floor, Phoenix, AZ 85003 
 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 63 of 68

This Message Is From an Untrusted Sender
You have not previously corresponded with this sender. Please use caution when you receive messages from new
senders. Always validate the sender first.
From:
Sarah Harrison
To:
William.Adrian@Maricopa.Gov; Gregory.Verkamp@Maricopa.Gov; Kimberly.Butler@Maricopa.Gov
Cc:
Jason Browne; Brian Fleury; Enrique Peralta; Alexis Camberos
Subject:
Denali Water Solutions-Comment for Rule 327
Date:
Tuesday, September 10, 2024 2:22:01 PM
Attachments:
Outlook-signature_.png
Denali Rule 327 Comment Letter FInal.pdf
Good afternoon, 
I am the Director of Environmental Compliance for Denali Water Solutions' facilities, and I participated in
the Webinar focused on the Draft Rule 327 a few weeks ago. Denali operates the composting facility for
the City of Pheonix located at 3060 S 27th Ave. I found the webinar very informative and was
appreciative to the fact that the staff at Maricopa County was willing to accept further comment on this
rule. As a leader in the composting industry, Denali would like to submit the attached letter for your
consideration. I understand that the District wants to announce the final draft of this regulation in the
coming weeks, so please reach out to me with any questions. We look foward to working with you. 
-Sarah 
Sarah Harrison • Environmental Director/Facility
Compliance
C: 229-326-1149
sarah.harrison@denaliwater.com
Return to Stakeholder #3: Comments #24 through #31
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 64 of 68

3308 Bernice Avenue, Russellville, Arkansas 72802 
479-498-0500  |  www.DenaliWater.com 
 
 
 
 
 
 
September 10, 2024 
 
Maricopa County Air Quality Department 
301 W. Jefferson St., Suite 410  
Phoenix, Arizona 85003 
 
Re:  
Comments on the Draft Rule 327 – Organic Material Processing   
 
Dear Air Quality Department Staff –  
 
Denali is an innovative organics diversion company that is committed to repurposing waste to 
create value added products.  Our work is essential to keeping water clean, building soil 
fertility with minimizing greenhouse gas emissions, and reducing reliance on landfills.  We are 
a leader in the composting industry with operations through various technologies that span 
the Country. 
 
Denali appreciates the opportunity to comment on the proposed regulations as well as the 
lengths staff has gone to involve stakeholders through the rule development process. 
Unfortunately, we have significant questions regarding the potential regulations described in 
your latest draft of Rule 327. We have concerns over this proposed regulatory package and its 
impacts on compost facilities throughout the District’s jurisdiction. Indeed, should these 
regulations be adopted in their current draft form, they will create an economic burden on our 
industry that will hamper numerous composting operations throughout the County. While our 
industry members are ardent supporters of environmental protection and the implementation 
of sustainable practices that will benefit the citizens of the state, we believe the control measures 
and management practices described in Rule 327 do not reflect real world conditions at facilities, 
will be burdensome in their application, and may hamper the ability of many cities and counties 
to continue landfill diversion activities.  
 
Scope 
The scope of emissions reductions required under this Rule includes both ozone precursor 
volatile organic compounds (VOCs) and particulate matter resulting from fire events. While 
Denali supports reasonable rules which protect the environment – and understand the current 
responsibilities the Department has in meeting Clean Air Act compliance – the current rule 
language, as written, is in part not able to be implemented at certain types of operations, placing 
a significant economic burden on the facilities within the affected sector. 
 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 65 of 68

Denali – along with our experienced consultant team – is happy to meet with District staff to 
discuss the significant challenges with the current rule language and the impractical nature of 
applying it at the City of Phoenix’s facility that we operate. 
 
Policy Recommendations 
In its current form, draft Rule 327 seeks to implement control measures that are tailored for 
windrow composting – both with proven compost cap and irrigation methods that have 
demonstrated emissions reductions at facilities in California where regulatory conditions have 
existed for over a decade – they do not appear to consider the type of turned aerated static pile 
(TASP) technology at our facility that is specifically designed to control VOC emissions and odors, 
requiring a significant investment in the control technologies and operations currently employed. 
 
Technical Concerns 
While we understand the District’s desire to achieve the highest feasible emissions reductions, 
the economic burden placed on composting operators by use of a Finished Compost Cover is both 
excessive and uncertain. The excessive costs lie in the loss of revenue caused by reducing 
throughput and sales of finished product at the facilities, as 20% to over 50% of site capacity will 
be occupied by finished compost; the required volume of finished compost for the “cap” would 
represent a one-time loss of sales, but the loss of processing capacity would be permanent. The 
operational and capital costs of a Finished Compost Cover are largely uncertain – given the lack 
of any available, proven technology with which to apply the cover or an assessment of the 
corresponding increased capital costs for equipment, operation and maintenance costs, or 
additional labor costs.  
 
Current technology use for installation of the Finished Compost Cover will cause an additional 
impact on facility capacity and throughput. Absent the development of any new technological 
advancement in compost application, current use of front loaders would be the sole functional 
option for delivery of the finished compost to the tops of the windrows. Commercial composting 
facilities typically maximize use of their available space by maintaining aisles of no more than ten 
feet between windrows. Use of a front loader for compost application of a cap will necessitate 
using aisles of twenty feet or more to allow a turning radius for the loader to attain a proper 
angle of address for efficiently and effectively dumping their load on the top of the windrow. The 
additional spacing between windrows will reduce the available composting space by 
approximately 40%, limiting throughput volume,revenues and overall, the amount of organic 
residuals that should be recycled vs going to landfill. 
 
At the City of Phoenix operations, given the current use of a negatively-aerated, turned windrow 
system, will be forced to apply a compost cap eight times (every three days for each of the eight 
separate piles created) as the active composting material is turned from aeration-zone to 
aeration-zone, adding a significant volume of materials across the full process.  
 
We fully support the current recommendations on assessing moisture content, as our 
experienced operators can readily attain accurate results with reasonable success (within 5%) by 
use of the manual squeeze ball test. 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 66 of 68

3308 Bernice Avenue, Russellville, Arkansas 72802 
479-498-0500  |  www.DenaliWater.com 
 
 
We do not believe that the requirement of section 304.3 (c) for corrective action at 160⁰F is a 
well-reasoned approach to fire mitigation. This temperature is common in composting piles and 
is far from a fire-critical level. Actively aerated composting piles have no demonstrated threat of 
fire generation (as stated previously regarding spontaneous combustion potential) and there is 
no evidence that, even at 180⁰F, fires from active composting have occurred. While temperatures 
above 180⁰F can reasonably be expected to limit microbial activity and lead to diminished 
composting activity, the fire risk is still significantly low. A reasonable approach may be to provide 
an exception for facilities using forced aeration and turning, as the buildup of low flash point 
gases will only represent a spontaneous combustion threat if they are allowed to build up over 
several weeks. 
  
Conclusions 
Denali believes that the Department needs to take prudent steps to reassess the current 
language in Rule 327, while also taking into account the potential future management of green 
and food waste materials in agricultural land application, and/or disposed of in landfills, should 
composting operations become non-existent or prohibitively costly. We have not seen where the 
Department, to date, has estimated the increased NOx and Particulate Matter emissions created 
by the need to apply the compost cap repeatedly. 
 
Denali has a commitment to effective recycling and environmental protection that is unwavering. 
The continued success of green and food waste recycling programs is dependent upon the 
development of cost-effective, practical regulations that will protect the environment in balance 
with the substantial benefits of composting operations to the sustainable future of our state and 
nation.  We look forward to continued participation in the development of this regulatory 
package, with an eye on results that are responsive to the need for landfill diversion—as provided 
by composting operators—while simultaneously improving the air quality of the state. 
 
In closing,  we believe that the Department’s proposed timeline for adoption of Rule 327 (by the 
end of this year) may need to be delayed, given the very short period of time available for review 
and comment on the highly complex draft Rule and, given that there are numerous technical 
questions related to proper implementation of a compost cap and irrigation system, required 
sampling and testing protocols, and time needed to review potential revisions that may result in 
response to comments from stakeholders. If you have any questions please do not hesitate to 
contact at sarah.harrison@denaliwater.com or 229-326-1149.  
 
Sincerely,  
 
Sarah Harrison 
Sarah Harrison 
Environmental Director of Facility Compliance, Denali Water Solutions 
 
Maricopa County • Air Quality Department • Rule 327 Report to the Board of Supervisors
Page 67 of 68

Maricopa County 
Air Quality Department 
Planning and Analysis Division 
Maricopa.gov/AQ