UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document

for

EPA ’ s Rulemaking

for the
California State Implementation Plan

El Dorado Air Quality Management District
Ozone Emergency Episode Plan

Prepared by: Vanessa Graham
Reviewed by: Andrew Steckel

May 20161

RULE IDENTIFICATION

- Agency EL Dorado County Air Quality Management District ( EDCAQMD )

S IP Approved

Plan None

Subject of this

TSD Ozone Emergency Episode Plan

Adopted

– January 12 , 201 6

Submitted

– April 6, 2016

Completeness
Finding Determination of Completeness letter : April 21, 2016

BACKGROUND

– Section 110(a) of Clean Air Act (CAA) require s each state to develop
and submit to the EPA a plan that provides for the implementation, maintenance, and
enforcement of the national ambient air quality standards (NAAQS). Section 110(a)(1)

also requires that each state make a new State Imp lementation Plan (SIP) submission
within 3 years after the promulgation of a new or revised primary or secondary NAAQS,
for approval into the existing SIP to assure that the SIP meets the applicable requirements
for the new or revised NAAQS. This type of S IP submission is commonly referred to as

an “infrastructure SIP”.

To fac ilitate planning efforts, the state of California is divided into air quality control
regions (AQCR). Each AQCR is assigned Priority I, II or III with respe ct to emergency episode classification, based on threshold levels specified in the Code of Federal
Regulations (CFR) at 40 CFR Part 51, Subpart H . Priority I and II areas have specific
emergency episode plan requirements designed to prevent ambient concentrations from
reaching sp ecified significant harm levels (SHL)

. Priority III areas have no emergency plan requirements.

SUMMARY

– AQCRs with ozone concentrations greater than 0.10 ppm must be
classified Priority I. Review of EDCAQMD 2011

- 201 4 air quality data revealed that

EDCAQMD exceeded the 0.10 threshold on numerous occasions 1 and recorded high one

hour ambient levels of 0. 117 ppm. 2 Therefore, EDCAQMD is considered a Priority I
region and is required to prepare an ozone emergency episode plan. 3 EDCAQMD’ s Ozone
Emergency Plan, adopted on January 12, 2016 , and submitted on April 6, 2016

, was developed to fulfill the Infrastructure SIP emergency episode requirements as outlined in

40 CFR Part 51

, Subpart H

.

E ach Priority I contingency plan must

, at a minimum 4 :

1. Specify two or more stages of episode criteria ;

1 El Dorado County Ozone Emergency Episode Plan , September 2015; page 1 Table 1

. 2 California Infrastructure SIP Emergency Episode Planning Technical Support Document, EPA, Region 9,

September 2014, pages 8

- 9.

3 Ibid.

4 40 CFR part 51, subpart H ( 51.153 ).2

2. Provide for public announcement whenever any episode stage has been determined

to exist;

3. Specify adequate emission control actions to be taken at each episode stage ;

4. P rovide for p rompt acquisition of forecasts of atmospheric stagnation conditions
and forecast updates as frequently as they are issue d by the National Weather

Service ;

5. Provide for i nspect ion of sources to ascertain compliance with applicable control
action requirements ;

6. Provide communication procedures for transmitting status reports and orders as to
emission control action to be taken during an episode stage, including contact with
public officials, major emission sources, public health, safety, and emergency
agencies and news media

.

EVALUATION AND AC TION

– EPA previously approved an analogous contingency
plan for Placer County

. 5 The El Dorado County Ozone Emergency Plan was largely

modelled after the April 15, 2015 Placer County Air Pollution Control District Ozone
Emergency Episode Plan . The El Dorado plan was tailor ed to meet the specific ozone

emission s generated within El Dorado County. Our evaluation of the El Dorado County
Ozone Emergency Episode P lan finds the plan to be sufficiently clear and enforceable
consistent with the general SIP enforceab ility requirement s of CAA Section 110(a)(2)

. This plan is specifically intended to address CAA Section 110(a)(2)(G) requirements for
an emergency episode plan or rule

, which is summarized in the list of six items above and
described in greater det ail in 40 CFR part 51, subpa rt H (40 CFR 51.150 through 51. 153 )

. The six requirements above are fulfilled by requirements o n pages seven thru eleven of the
plan. There were no deficiencies found

, and the addition of the Ozone Emergency Episode

P lan strengthens the SIP. Nothing in the EDCAQMD plan, or EPA’s approval of this plan

, interferes with EPA’s independent federal authority in CAA Section 303.

EPA RECOMMENDED ACTIONS

– EPA staff recommends full approval of the plan
as adopted on January 12, 2016 and submitted on April 6, 2016

.

ADDITIONAL RECOMMENDATIONS FOR THE NEXT RULE REVISION

– EPA

staff have no additional recommendations.

REFERENCES

1. California Infrastructure SIP prepared by ARB; Report Release December 23,

2013

. 2. California Infrastructure SIP Emergency Episode Planning Technical Support
Document September 2014; prepared by USEPA, Region 9

. 3. 40 CFR Part 51

, Subpart H

- Prevention of Air Pollution Emergency Episodes

. 4. USEPA Guidance on Infrastructure State Implementation Plan (SI P) Elements

under Clean Air Act Sections 110(a)(1) and 110(a)(2)

, Stephen D. Page (EPA)

, September 13, 2013.

5 80 FR 76230 January 7, 20163

5. Placer County Ozone Emergency Episode Plan (80 FR 76230, January 7, 2016)

6. 65 FR 53602

, September 5, 2000 (EPA approval of SMAQMD Rule 701).