UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document 

for

EPA’s Direct Final Rulemaking

for the

California State Implementation Plan

Placer County Air Pollution Control District Rule 247

Natural Gas-Fired Water Heaters, Small Boilers and Process Heaters

Prepared by: Nicole Law

August 2014
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Agency: Placer County Air Pollution Control District (PCAPCD)

SIP Approved Rule: none

Superseded Submittals: none

Subject of this TSD: Rule 247 – Natural Gas-Fired Water Heaters, Small 

Boilers and Process Heaters

Amended – February 13, 2014

Submitted – May 13, 2014

BACKGROUND – Placer County APCD is nonattainment for the 8 hour Ozone 

standard. As a part of the State Implementation Plan, PCAPCD committed to 

adopt a new rule to regulate oxides of nitrogen (NOx). Rule 247 was adopted to 

fulfill that commitment as it regulates water heaters and boilers with rated heat 

capacity greater than 75,000 BTU/hr and less than 5 million BTU/hr. 

RULE SUMMARY -

Rule 247 establishes NOx limits and certification requirements for natural gasfired water heaters, boilers, and process heaters. It also describes related 

recordkeeping, labelling, and test methods. Rule 247 does not apply to existing

units, as it is a point of sale rule. Rule provisions include:

1. Limits on NOx emissions to 20 ppmv at 30% oxygen for natural gas-fired 

water heaters, boilers, or process heaters.

2. The rule effective date is January 1, 2015 when no person is allowed to 

offer for sale, sell or install a natural gas-fired water heater, boiler or 

process heater which does not comply with the emission limit.

3. Manufacturers of water heaters, boilers or process heaters subject to the 

rule are required to submit to the Air Pollution Control Officer 30 days prior 

to sale a statement that the unit is in compliance with the emission units. 

Another option is for manufacturers to submit to the District certifications 

approved by either the South Coast Air Quality Management District 

(SCAQMD) or the San Joaquin Valley Air Pollution Control District 

(SJVAPCD).

4. Labelling requirements for manufacturers describe what information should 

be included on the units as well as the carton.

5. Manufacturers are responsible for keeping certification reports, test reports, 

and certification statements for as long at the unit is offered for sale or five 

years, whichever is longer.
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6. Various allowable test methods are listed for determining certification and 

compliance with the rule.

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 - EPA’s Alternative Control Techniques Document (ACT) titled, 

“NOx Emissions from Industrial/Commercial/Institutional (ICI) Boilers” (EPA453/R-94-022-1994/03, March 1994), CARB’s RACT/BARCT guidance 

titled, “Industrial, Institutional, and Commercial Boilers, Steam Generators, 

and Process Heaters” (July 18, 1991), and other state and local rules for 

this category were used to help evaluate the stringency of the rule’s control

requirements. 

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 SIPapproved 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. The rule requirements and applicability are clear, and the recordkeeping, 

reporting and other provisions sufficiently ensure that affected sources and 

regulators can evaluate and determine compliance with Rule 247 

consistently. 

2. The submitted rule is more stringent than CARB’s RACT/BARCT guidance,

and the controls are comparable to those in EPA’s ACT and other California 

District rules for this category, including Sacramento Metropolitan Air Quality 

Management District Rule 411 and 414. Accordingly, we find that the 

control requirements in this rule represent RACT-level control for this source 

category. 

3. 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 on-going process for ensuring that requirements for 

RFP and attainment of the NAAQS are met, and (2) no previous version of 
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this rule is in the SIP, so approval of this version only improves the SIP and 

does not modify any existing SIP control requirement.

RULE DEFICIENCIES – We have identified no deficiencies with Rule 247 

sufficient for EPA to propose less than full approval.

ADDITIONAL RECOMMENDATIONS FOR THE NEXT RULE REVISION - The 

following revisions are not currently the basis for rule disapproval, but are 

recommended for the next time the rule is amended.

1. Section 103.2 provides an exemption for water heaters used to heat 

pools/spas with a rated heat input capacity less than or equal to 400,000 

Btu/hr. Consider adopting limits for these units as in San Joaquin Valley

APCD Rule 4308 Section 5.0 Table 1 (for instantaneous water heaters and 

pool heaters between 75,000 and 400,000 btu/hr the limit is 55 ppmv NOx 

at 3% O2) and Sacramento Metropolitan AQMD Rule 414 Section 301 (for 

pool/spa heaters between 75,000 and 400,000 Btu/hr the limit is 55 ppmv 

at 3% O2). 

2. Section 402.2 allows submittal of certification as approved by the San 

Joaquin Valley APCD. The rule language states “A certification of a model 

to San Joaquin Qir Management District Rule 4307...” but should state “A 

certification of a model to San Joaquin Valley Air Pollution Control District

Rule 4307....”

3. Section 502.3 references a South Coast AQMD test method by number. 

Consider including the title of the test method in this section as is 

recommended on page 13 of EPA’s Guidance Document for Correcting 

Common VOC & Other Rule Deficiencies.

EPA ACTION -

The submitted Rule 247 strengthens the SIP, and the associated District staff 

report projects it will reduce NOx emissions by 1.01 tons/day in 2025. The rule 

satisfies the applicable CAA §110 requirements. Therefore, EPA staff 

recommends a full approval of Rule 247 pursuant to CAA §110(k)(3). 

REFERENCES -

1. PCAPCD Rule 247, Natural Gas-Fired Water Heaters, Small Boilers and 

Process Heaters, as amended February 13, 2014 and submitted to EPA on 

May 13, 2014.

2. PCAPCD Rule 247, Natural Gas-Fired Water Heaters, Small Boilers and 

Process Heaters, as adopted October 10, 2013.
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3. “Alternative Control Techniques Document- NOx Emissions from 

Industrial/Commercial/Institutional (ICI) Boilers” EPA-453/R-94-022-

1994/03, March 1994. 

http://www.epa.gov/groundlevelozone/SIPToolkit/ctg_act/199403_nox_epa

453_r-94-022_ici_boilers.pdf

4. “Determination of Reasonably Available Control Technology and Best 

Available Retrofit Control Technology for Industrial, Institutional, and 

Commercial Boilers, Steam Generators, and Process Heaters,” CARB, July 

18, 1991.

5. “Issues Relating to VOC Regulation Cutpoints, Deficiencies, and 

Deviations,” (a.k.a., Bluebook) EPA OAQPS, May 25, 1988 (web citation).

6. “Guidance Document for Correcting Common VOC & Other Rule 

Deficiencies,” (a.k.a., Little Bluebook), EPA Region 9, August 21, 2001 

(http://www.epa.gov/region09/air/sips/littlebluebook2001.pdf).