UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document 

for

EPA’s Direct Final Rulemaking

for the

California State Implementation Plan

YOLO-SOLANO AIR QUALITY MANAGEMENT DISTRICT

Rule 1.1, General Provisions and Definitions 

Prepared by: Arnold Lazarus

Reviewed by: Andy Steckel

October 2014
RULE IDENTIFICATION 

Agency: Yolo-Solano Air Quality Management District 

(YSAQMD)

SIP Approved Rule: Rule 1.1 - General Provisions and Definitions

Adopted – August 13, 1997

Submitted - July 26, 2000

EPA Approved - March 22, 2004 (69 FR 13234)

Subject of this TSD: Rule 1.1 - General Provisions and Definitions

Amended - May 8, 2013

Submitted - February 10, 2014

Background

Yolo-Solano Air Quality Management District (YSAQMD) Rule 1.1 - General 

Provisions and Definitions, contains definitions for specific terms applicable to all 

District rules. EPA most recently approved a version of Rule 1.1 in 2004. 

Revisions incorporated in the submitted 2013 version include:

1. Administrative and formatting changes. 

2. Addition of exempt organic compounds to coincide with those that EPA 

has determined to have negligible photochemical reactivity as listed in Title 

40 of the Code of Federal Regulations Part 51.100 (40 CFR 51.100). 

EPA Evaluation

These revisions do not have a direct effect on air pollution emissions, but they 

improve clarity and enforceability of other YSAQMD Rules which do reduce 

emissions. 

EPA’s criteria for rule approval are satisfied by the following:

1. The definitions are clear and help make other provisions enforceable so it 

is consistent with enforceability requirements of the federal Clean Air Act 

(CAA) §110(a)(2)(A). Further discussion of one enforceability concern is 

provided below in the section titled, “Public Access to Records, reports and 

information.” 

2. Because these definitions do not establish emission controls but provide 

clarification to requirements found elsewhere, we have determined that 

they will not interfere with any applicable requirement concerning 

attainment and reasonable further progress (RFP) or any other applicable 

requirement of the Act (CAA §110(l)) or modify, in a nonattainment area, 

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

(CAA §193).

3. The rule does not directly establish emission controls, so it is not relevant 

to evaluate it regarding stringency.

Recommended Action

EPA staff recommends approval of YSAQMD Rule 1.1 under CAA §110(k) as 

meeting the requirements of CAA §110(a) and Part D. Approval of the definitions 

should not be interpreted as EPA approval of the other rules in which these 

definitions are used.

Public Access to records, reports and information

As currently written, we believe YSAQMD Rule 1.1 Section 232.4 “Public 

Records” could lead to different interpretations on whether emissions data and the 

information used to calculate emissions data are public records and whether 

Section 232.4 is consistent with CAA Section 114(c) on the availability of records, 

reports and information to the public. Section 232.4 mirrors California Government 

Code 6254.7(e) and states:

232.4 Notwithstanding any other provision of law, all air pollution 

emission data, including those emission data which 

constitute trade secrets as defined in Section 237 of this 

rule, are public records. Data used to calculate emission 

data are not emission data for the purposes of this rule 

and data which constitute trade secrets and which are 

used to calculate emission data are not public records.

CAA Section 114(c) “Availability of records, reports, and information to public; 

disclosure of trade secrets” stipulates that any records, reports or information 

obtained by the EPA shall be available to the public. The Act further states that 

with the exception of “emissions data”1, records, reports or information which are 

entitled to protection as a trade secret are to be considered confidential. We 

interpret this section to mean that emissions data, including information used to 

calculate emissions data (i.e., the final aggregate emissions value) shall be 

available to the public. Other records, reports or information that are not 

considered emissions data but are likely to cause substantial competitive harm if 

publically disclosed, could be considered confidential and would not be a public 

record. 

YSAQMD indicates it interprets Rule 1.1 Section 232.4 to be consistent with the 

CAA and states that it considers information such as product formulations or 

1 EPA defines emissions data at 40 CFR 2.301(a)(2)(i).

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actual throughputs as protected data.2 YSAQMD’s interpretation is also consistent 

with a 1993 California Attorney General opinion3 on public access to permit 

information.

Therefore, with YSAQMD’s clarification and California Attorney General’s opinion, 

it is our understanding that YSAQMD interprets the handling of emissions data 

consistent with the CAA. We also note that Rule 1.1 Section 232.4 was previously 

approved into the SIP and was not changed in the current rule amendments. 

While we recommend removal of the second sentence of paragraph 232.4 to 

more clearly conform to the CAA, this sentence does not justify less than full 

approval of this rule at this time.

Recommendations

Definition 223: Multiple-Chamber Incinerator. The ASTM method is missing the 

applicable year. EPA recommends it be updated to ASTM C-24-09 (2013).

References

1. District Draft Staff Report for the proposed revisions to Rule 1.1, General 

Provisions and Definitions, October 22, 2013.

2. District Rule 1.1 General Provisions and Definitions, Clean Copy, 

Submitted - February 10, 2014.

3. District Rule 1.1 General Provisions and Definitions, Struck Copy, 

Submitted - February 10, 2014.

4. California Government Code Section 6254.7 (d).

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2 September 19, 2014 email from YSAQMD (Paul Hensleigh) to EPA Region IX (Andrew Steckel), 

“RE: Yolo-Solano Rule 1.1. YSAQMD states product formulation or actual throughputs as 

examples that warrant protection as a trade secret.

3 California’s Authority to Implement Title V (Operating Permits) of the Clean Air Act, State of 

California, Office of the Attorney General, November 12, 1993.

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