United States Environmental Protection Agency, Region 9 

Air Division 

Technical Support Document 

for 

EPA’s Notice of Proposed Rulemaking 

for the 

California State Implementation Plan 

Sacramento Metro Air Quality Management District’s 

Rule 414, Water Heaters, Boilers and Process Heaters Rated Less Than 1,000,000 BTU per Hour 

Prepared by: Idalia Perez 

September 2011 
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Sacramento Metro Air Quality Management District (SMAQMD) 

Submitted Rule 

SMAQMD Rule 414, Water Heaters, Boilers and Process Heaters Rated Less Than 1,000,000 

BTU per Hour: 

§ Amended: March 25, 2010 

§ Submitted: April 5, 2011 

§ Determined complete: May 6, 2011 

Previous Rule Submittals 

There are no outstanding submittals of Rule 414. 

SIP-Approved Rule 

§ Adopted: August 1, 1996 

§ Approved by EPA: April 20, 1999 (64 FR 19277) 

Rule Summary 

Rule 414 limits NOx and CO emissions from water heaters, boilers and process heaters rated 

below 1,000,000 btu/hour. The rule applies to manufacturers, distributors, sellers and installers 

of these units. 

Changes to the rule

The District amended Rule 414 to extend the applicability to larger units, other fuel types and to 

lower the emission limits. 

Heat Input 

Range 

(Btu/hour) 

Type NOx limit effective 

1/1/11 (ng/joule; 

ppm @ 3% O2) 

NOx limit effective 

1/1/13 (ng/joule; 

ppm @ 3% O2) 

CO limit 

(ppm @ 3% 

O2) 

< 75,000 Mobile Home 40; 55 – – 

< 75,000 All others 10; 15 – – 

75,000 to < 

400,000 

Pool/Spa 40; 55 – – 

75,000 to < 

400,000 

All other 40; 55 14; 20 – 

400,000 to < 1 

million 

All types 14; 20 – 400 

Other changes to the rule include added definitions, monitoring and recordkeeping requirements 

that improve rule clarity and enforceability. 

Effects on Emissions 

According to the staff report, the District estimates a reduction of 0.71 tons of NOx per day by 

the year 2018 due to the implementation of this rule. 

Rule Evaluation 

Generally, SIP rules must be enforceable (see section 110(a) of the Act), must require 

Reasonably Available Control Technology (RACT) for major sources in nonattainment areas 
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(see sections 182(b)(2) and 182(f)), and must not relax existing requirements (see sections 110(l) 

and 193). In addition, Section 172(c)(1) of the Clean Air Act (CAA) requires nonattainment 

areas to implement all reasonably available control measures (RACM), 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 (RACT), as expeditiously as practicable. 

Although the SMAQMD regulates an ozone nonattainment area

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(40 CFR 81), submitted Rule 

414 is not subject to RACT requirements because it is applicable to sources that are too small to 

exceed the major source threshold. Because the SMAQMD regulates an ozone nonattainment 

area (40 CFR 81), submitted Rule 414 must fulfill RACM requirements. 

Guidance and policy documents that we used to define enforceability requirements include the 

following: 

• Issues Relating to VOC Regulation, Cutpoints, Deficiencies, and Deviations (the "Blue 

Book"), US EPA, OAQPS (May 25, 1988). 

• Guidance Document for Correcting Common VOC and Other Rule Deficiencies, EPA 

Region IX (August 21, 2001, the “Little Bluebook”). 

• State Implementation Plans; General Preamble for the Implementation of Title I of the 

Clean Air Act Amendments of 1990, 57 FR 13498 (April 16, 1992); 57 FR 18070 (April 

28, 1992). 

• State Implementation Plans; Nitrogen Oxides Supplement to the General Preamble for 

the Implementation of Title I of the Clean Air Act Amendments of 1990 (the "NOX

Supplement to the General Preamble"), US EPA, 57 FR 55620 (November 25, 1992). 

• Clean Air Fine Particle Implementation Rule, 72 FR 20586 (April 25, 2007) 

• 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). 

http://www.arb.ca.gov/ractbarc/boilers.pdf

• Alternative Control Techniques Document-- NOx Emissions from 

Industrial/Commercial/Institutional (ICI) Boilers, US EPA 453/R-94-022 (March 1994). 

http://www.epa.gov/ttn/catc/dir1/icboiler.pdf 

Although submitted Rule 414 is not subject to RACT and at this time we are not making a 

determination of its ability to implement RACT, we note that this rule requires controls that 

appear to be "reasonably available" considering technological and economic feasibility, for the 

reasons cited below: 

- Emission limits in Rule 414 are comparable to emission limits in South Coast Air Quality 

Management District’s Rules 1121 and 1146.2 and to limits in San Joaquin Valley 

Unified Air Pollution Control District’s Rules 4902 and 4308, the other large California 

 

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SMAQMD also regulates a nonattainment area under the 2006 24-Hour PM2.5 National Ambient Air Quality 

Standard (NAAQS). 40 C.F.R. § 81.305 (2010). By December 14, 2012, California must submit a revision to the 

State Implementation Plan (SIP) for this nonattainment area that provides for, among other things, implementation 

of all RACM as expeditiously as practicable (including RACT for existing sources). CAA § 172(a)(2)(A), (b) & 

(c)(1), 74 FR 58689 (Nov. 13, 2009). EPA will take action on this RACM demonstration in a separate rulemaking. 
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ozone nonattainment agencies. These generally have among the most stringent stationary 

source requirements nationwide, and we are not aware of other reasonably available 

technological or operational controls likely to significantly reduce additional emissions 

from this activity. 

- The submitted rule is as stringent as CARB’s RACT/BARCT guidance for the largest 

units subject to this rule. 

CAA §172(c)(1) requires nonattainment areas to implement all reasonably available control 

measures, including such reductions in emissions from existing sources in the area as may be 

obtained through the adoption, at a minimum, of RACT, as expeditiously as practicable. The 

Sacramento Metro area is designated as nonattainment for the 2006 fine particulate matter 

(PM2.5) National Ambient Air Quality Standards (NAAQS) and designated and classified as 

severe nonattainment for the 1-hour and 8-hour ozone NAAQS (see 40 CFR part 81). Small 

boilers can emit direct PM2.5, as well as NOx, which is a precursor to both PM2.5 and ozone. 

Therefore, SMAQMD must implement RACM for boilers if those measures will advance 

attainment of the NAAQS for PM2.5 or ozone, when considered collectively with other 

reasonable measures. Additional control measures for small boilers may be required pursuant to 

CAA §172(c)(1) if both: (1) additional measures are reasonably available; and (2) these 

additional reasonably available measures will advance attainment in the area when considered 

collectively. In separate rulemakings, EPA will take action on the State’s RACM demonstration 

for PM2.5 and ozone based on an evaluation of the control measures submitted as a whole and 

their overall potential to advance the applicable attainment dates in the District. See 40 CFR §§ 

51.1010, 51.912(d). 

Recordkeeping and other compliance provisions in the rule ensure that the requirements are 

adequately enforceable. Lastly, since the limits in the submitted are more stringent than those in 

the SIP-approve rule, the submitted rule strengthens the SIP. We propose to determine that our 

approval of the submittal would comply with CAA sections 110(l) and 193, because 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 the submittal strengthens the 

SIP as there is no rule for this category currently in the SIP and would insure equivalent or 

greater emission reductions of NOx. 

Suggested Rule Improvements 

Although not currently basis for rule disapproval, EPA recommends that the SMAQMD 

eliminate the reference to the California Health and Safety Code in the definition of 

“Recreational Vehicle” in provision 211. 

Recommendation 

EPA staff recommends approval of SMAQMD submitted rule 414 for incorporation into the 

California SIP. 

Other References 

1. Clean copy of submitted Rule 414 

2. Strikeout copy of submitted Rule 414 

3. Staff Report for Rule 414, dated January 15, 2010 

4. SIP-approved version of Rule 414