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

San Joaquin Valley Unified Air Pollution Control District’s

Rule 4 902

, Residential Water Heaters

Prepared by: Idalia Perez

December 2009San Joaquin Valley Unified Air Pollution Control District (SJVAPCD)

Submitted Rule

SJV APCD Rule 4 902

, Residential Water Heaters:

 Adopted: March 1 9 , 200 9

 Submitted: April 29 , 2009

 Determined complete : July 20, 2009

Previous Rule Submittals

There are no outstanding submittals of Rule 4902

.

SIP

- Approved Rule

 Adopted: June 17, 1993

 Approved by EPA : February 1 7 , 2004 ( 69 FR 7370 )

Rule Summar y

Rule 4 902 limits NOx emiss ions from residential water heaters

.

Rule Amendments

Rule 4 902 was amended to ex pa nd the applicability of the rule and strengthen the emission limits

for NOx.

Section 4 (Exemptions) was changed to eliminate exemptions f or pool heaters starting January 1,

2010

.

Section 5 (Requirements) was changed to include the following new NOx limits:

Mobile home water heater

– 40 ng NOx/J of heat output (Compliance 1/1/10)

Pool water heater

– 40 ng NOx/J of heat output (Compliance 1/1/10)

Other water heaters

– 10 ng NOx/J of heat output (Compliance 1/1/10)

Instantaneous water heaters

– 14 ng NOx/J of heat output (Compliance 1/1/12)

Other changes were done to improve consistency, clarity and enforceability of the Rule.

Effects on Emissions

The staff report indicate s that Rule 4902 will lead to an approximate reduction of 0.85 tons of

NOx per day

.

Rule Evaluation

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

CAA); must require Reasonably Available Control Technology (RA CT) for major sources in

nonattainm ent areas (see CAA section 182(b )(2) and 182(f) ); must not interfere with applicable

requirements, including requirements concerning attainment (see CAA section 110(l)); and must

not relax existing requirements in effect prior to enactment of the 1990 CAA amendments (see

section 193).Although t he SJV APCD regulates a se rious (8

- hour) and extreme (1

- hour) ozone nonattainment

area (40 CFR 81) , submitted Rule 4 902 is not subject to RACT because it is applicable to

sources t hat are too small to exceed the major source threshold.

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 ” ).

On April 16, 2009, SJVAPCD adopted its “2009 RACT SIP,” which provides the District’s

demonstrat ion that RACT is implemented for all appropriate activities. This includes several

pages discussing Rule 4 902 (attached)

. The Rule was not reviewed to determine its fulfillment of

RACT thus we are not making a statement of its merit in this regard.

R ec ordkeeping and other compliance provisions in the rule ensure that the requirements are

adequately enforceable. The elimination of the exemption for pool water heaters and the

addition of more stringent NOx emission limits make the amendments a strengthen ing of the

SIP. Thus, approval of the submitted rule does not relax the SIP and s atis fies CAA §110(l) and

§193.

Recommendation

EPA staff recommend s approval of SJV APCD submitted rule 4 902 for incorporation into the

California SIP

.

Attachments

1. Submitte d Rule 4 902 (Clean Copy)

2. Submitted Rule 4 902 (Strikeout Copy)

3. Staff Report

4. SIP

- approved version of Rule 4 902

5. SJV APCD RACT Demonstration for Ozone SIP, pages 4

- 372

– 4

- 37 4