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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document 

for

EPA’s Rulemaking

for the

Arizona State Implementation Plan

Arizona Revised Statutes §49-424

Prepared by: Nancy Levin

October 31, 2016
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RULE IDENTIFICATION 

Agency Arizona Department of Environmental Quality

SIP Approved 

Rule

A.R.S. Title 49-424. Duties of the department.

Effective: August 24, 2012

Submitted: August 24, 2012

EPA Approved: November 5, 2012 (77 FR 66398)

Subject of this 

TSD

A.R.S. Title 49-424. Duties of the department.

Effective: April 18, 2014

Submitted: December 21, 2015

Completeness 

Finding

Determination of Completeness letter: March 21, 2016

 

BACKGROUND 

The previous SIP-approved version of ARS §49-424 established requirements for the Arizona 

Department of Environmental Quality to conduct activities to regulate air pollution in the state. 

RULE SUMMARY 

A.R.S. Title 49-424 Duties of the department

This Statute requires the Arizona Department of Environmental Quality (ADEQ) to establish and run an 

air pollution control program, including establishing air pollution control districts (APCD). 

A summary of the duties of the department are as follows:

1. Determine whether air sheds can be reasonably identified and whether air pollution can be 

controlled by establishing air pollution control districts within well-defined geographical areas.

2. Make continuing determinations of the quantity and nature of emissions of air contaminants, 

topography, wind, temperature conditions, possible atmospheric chemical reactions, economic 

development, the use, feasibility and economic impact of air control devices, the effect on human 

health and property, the effect on industry and other matters to better understand air pollution 

and control.

3. Establish exceptional event policies with the planning agency (per 49-406(A)) and the APCD,

taking into account the state’s unique circumstances. 

4. Determine health based standards, transmit minimum standards to county boards of supervisors. 

5. Conduct investigations, inspections and tests to carry out the duties of this section.

6. Hold hearing and compel the attendance of witnesses and production of records (per 49-432).

7. Develop air pollution control plans.

8. Encourage voluntary cooperation with persons, groups or other states.

9. Encourage political subdivisions to handle air pollution problems in their jurisdictions, and 

provide technical and consultative assistance as necessary.

10. Compile and publish reports, data and statistics related to this section.

11. Develop and disseminate air quality dust forecasts for PM10 nonattainment or maintenance areas.
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Changes from prior SIP-approved rule (Additions in CAPS; deletions in strikeout)

 Section 2. Make continuing determinations of the quantity and nature of emissions of air contaminants, 

topography, wind and temperature conditions, possible chemical reactions in the atmosphere, the 

character of development of the various areas of the state, the economic effect of remedial measures on 

the various areas of the state, the availability, use and economic feasibility of air-cleaning devices, the 

effect on human health and danger to property from air contaminants, the effect on industrial operations 

of remedial measures and other matters necessary to arrive at a better understanding of air pollution and 

its control. In a county with a population in excess of one million two hundred thousand persons 

according to the most recent United States decennial census, the department shall locate a monitoring 

system in at least two remote geographic sites.

 Section 11. Develop and disseminate air quality dust forecasts for the Maricopa county PM10

nonattainment OR MAINTENANCE area AND ANY OTHER PM10 NONATTAINMENT OR 

MAINTENANCE AREAS THAT ARE DESIGNATED IN THIS STATE FROM AND AFTER 

DECEMBER 31, 2011. Each forecast shall identify a low, moderate or high risk of dust generation for 

the next five consecutive days and shall be issued by noon on each day the forecast is generated. At a 

minimum, the forecasts shall be posted on the department's website and distributed electronically. When 

developing these forecasts, the department shall consider all of the following: (a) Projected 

meteorological conditions for the Maricopa county PM10 NONATTAINMENT OR MAINTENANCE

area, including all of the following...

EVALUATION CRITERIA

The following criteria were used to evaluate the submitted rule. 

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

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

Common VOC & Other Rule Deficiencies, EPA Region 9, August 21, 2001) were used to help 

evaluate compliance with the CAA §110(a)(2)(A) requirement for enforceability.

2. Stringency –Nonattainment areas are required to demonstrate reasonably available control 

measures (RACM), including reasonably available control technology (RACT). CAA Section 

172(c)(1) requires that each attainment plan “provide for the implementation of all reasonably 

available control measures as expeditiously as practicable (including such reductions in 

emissions from existing sources in the area as may be obtained through the adoption, at a 

minimum, of reasonably available control technology), and shall provide for the attainment of 

the national primary ambient air quality standards.” RACM findings are generally made in 

context of an overall attainment demonstration. RACT finding are generally made for rules that 

contain control measures or limits. 

3. SIP Relaxation - CAA §110(l) prohibits EPA from approving any SIP revision that would 

interfere with any applicable requirement concerning attainment and reasonable further progress 

(RFP) or any other applicable requirement of the CAA. In addition, CAA §193 prohibits the 

modification of any SIP-approved control requirement in effect before November 15, 1990, in a 

nonattainment area.

EPA EVALUATION 

A summary of our evaluation of the three criteria follows.

1. Enforceability - The rule revisions regarding development of air quality dust forecasts are clear 

and specific. The revision extends the current requirement to prepare a forecast for the Maricopa 

county PM10 nonattainment area, by adding “or Maintenance area.” It also extends the 

requirement to include any other nonattainment areas designated after December 31, 2015. These 
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and other provisions sufficiently ensure that affected sources and regulators can evaluate and 

determine compliance with ARS §49-424 consistently as required by CAA §110(a). 

2. Stringency – This is an administrative rule. Therefore, we are not evaluating it for RACM or 

RACT. 

3. SIP Relaxation: We propose to determine that our approval of the submittal would comply with 

CAA §§110(l) and 193 because (1) the proposed SIP revision would not interfere with the ongoing process for ensuring that requirements for RFP and attainment of the NAAQS are met, and 

(2) the requirements in the submitted rule are more stringent than the existing SIP-approved 

requirements that they would replace.

EPA ACTION

The submitted ARS 49-424 strengthens the SIP. The rule largely fulfils the relevant CAA §110 and part 

D requirements. Therefore, EPA staff recommends approval of ARS 49-424 pursuant to CAA 

§110(k)(3) and §301(a). 

REFERENCES

1. “Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations,” (a.k.a., Bluebook) 

EPA OAQPS, May 25, 1988.

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

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

3. Arizona Department of Environmental Quality 2015 West Pinal Moderate PM10 Nonattainment 

Area SIP, Appendix G, Air Quality Division, December 21, 2015 Final.