UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document 

for

EPA’s Rulemaking

for the

California State Implementation Plan

Placer County Air Pollution Control District Rule 250

Stationary Gas Turbines

Prepared by: Kevin Gong

April 20, 2016
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RULE IDENTIFICATION -

Agency Placer County Air Pollution Control District (PCAPCD)

SIP Approved 

Rule

Rule 250 – Stationary Gas Turbines

Adopted – October 17, 1994

Submitted – October 19, 1994

EPA Approved – August 23, 1995 (60 FR 43713)

Subject of this 

TSD

Rule 250 – Stationary Gas Turbines

Amended – October 8, 2015

Submitted – March 11, 2016

Completeness 

Finding

Determination of Completeness letter – April 19, 2016

BACKGROUND

PCAPCD regulates a portion of the Sacramento Metropolitan Nonattainment Area, which 

is classified as a “severe” nonattainment area (NAA) for the 1994 1-hour ozone National 

Ambient Air Quality Standard (NAAQS), and for the 1997 8-hour ozone and 2008 8-hour 

ozone NAAQS (see 40 CFR part 81). The Clean Air Act (CAA) requires that for areas 

classified as moderate or above nonattainment, the State must submit revisions to the 

State Implementation Plan (SIP) requiring the implementation of reasonably available 

control technology (RACT) (see sections 182(b)(2) and 182(f)). This rule was revised in 

part to ensure continued compliance with the CAA RACT requirement and to update the 

rule to comply with EPA policy on start-up and shutdown emissions.

RULE SUMMARY

Rule 250 limits oxides of nitrogen emissions (NOx) from stationary gas turbines in Placer 

County. It includes exemptions for laboratory and testing units, firefighting and flood 

control units, emergency standby and small units, and low-use units. The rule also 

contains generally applicable emission limits, operating and emission limits for units in 

startup and shutdown, monitoring and recordkeeping requirements, and references for 

test methods. Changes to Rule 250 from the SIP-approved version include:

1. Removal of exemptions for pipeline and chemical processing turbines, as none 

exist in the district, and addition of an exemption for low-use units. 

2. Removal of obsolete definitions, and the inclusion of definitions for performance 

testing, startup and shutdown.

3. Simplification of emission limitations, through the removal of efficiency factor 

calculations.
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4. Inclusion of startup and shutdown emission limits and operating procedures to 

minimize emissions during these conditions.

5. Requirements for all units to install NOx monitors, unless exempt.

6. Changes in recordkeeping practices to require longer maintenance of records (5 

years instead of 2).

7. Other minor changes to improve clarity and reduce redundancy in language.

EVALUATION CRITERIA

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. In addition, we refer to Restatement 

and Update of EPA’s SSM Policy Applicable to SIPs (80 FR 33839, June 12, 2015), 

with respect to emissions during start-up, shut-down and malfunction (SSM) 

conditions discussed in Rule 250. In general, this EPA policy clarifies the 

requirement for continuous emission limitations, consistent with the CAA.

2. Stringency - SIPs must require RACT for each category of sources covered by a 

Control Technique Guideline (CTG) document as well as each major source in 

ozone nonattainment areas (see sections 182(b)(2) and 182(f)). While there is no 

CTG for this source category, EPA has published an Alternative Control Techniques 

(ACT) document titled, “NOx Emissions from Stationary Gas Turbines” (EPA 453/R93-007, January 1993) which describes available control techniques and their 

estimated costs. This ACT and other state and local rules for this category were 

used to help evaluate the RACT requirements of CAA §182(b)(2) and §182(f). 

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 SIP-approved 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 provisions of Rule 250 clearly define the types of turbines that must comply 

with this rule. Requirements are clearly written, and the monitoring, 

recordkeeping, and reporting provisions will sufficiently ensure that any affected 

sources can determine compliance against the outlined limits.
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The previous version of Rule 250 excluded startup and shutdown emissions from 

control measures, but the most recent revision removes the exemption and 

replaces it with new restrictions during these operating periods. Combined cycle 

turbine units now must comply with emission limits during startup and shutdown. 

Simple cycle units must operate in a manner that minimizes emissions during 

startup and shutdown, including: following manufacturer’s recommendations for 

operation during startup and shutdown, maintaining proper air to fuel ratios, and 

initiating water injection as soon as reasonably possible. These numerical limits 

and work practices comply with EPA’s recently updated policy by establishing 

continuous emission limitations during SSM events.

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2. The submitted rule is as stringent as other California District rules for this category, 

including Yolo-Solano AQMD Rule 2.34, and Mojave Desert AQMD Rule 1158, and 

it is more stringent than EPA’s 1993 ACT guideline. As a result, we have 

determined that this rule fulfills RACT requirements. New rule provisions 

regulating operations and emissions during startup and shutdown operations 

improve stringency in comparison to the SIP-approved version of this rule.

The deletion of a category for units 10 megawatt and larger, operating without 

selective catalytic reduction (SCR) and a higher emission limit, has the effect of 

requiring any units subject to the rule at that size to comply with the more 

stringent limits for 10 megawatt and larger units operating with SCR (now 

applicable to all units at that size). The new rule also removes exemptions for gas 

pipeline and chemical processing turbines.

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 ongoing process for ensuring that requirements for RFP and attainment of 

the NAAQS are met, and (2) the emission limits in the submitted rule are more 

stringent than the existing SIP-approved control requirements that they would 

replace.

EPA ACTION

The submitted Rule 250 strengthens the SIP for the reasons outlined above, and the rule 

fulfills the relevant CAA §110 and part D requirements. Therefore, EPA staff recommends 

approval of PCAPCD Rule 250 pursuant to CAA §110(k)(3) and §301(a). 

REFERENCES

1. “Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations,” 

(a.k.a., Bluebook) EPA OAQPS, May 25, 1988.

 

1 As outlined in Section VII (“Clarifications, Reiterations and Revisions to EPA’s SSM Policy”) of 

Restatement and Update of EPA’s SSM Policy Applicable to SIPs, 80 FR 33839 (June 12, 2015).
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2. “Guidance Document for Correcting Common VOC & Other Rule Deficiencies,” 

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

3. Placer County Air Pollution Control District Rule 250, “Stationary Gas Turbines,” as 

amended October 8, 2015 and submitted to EPA on March 11, 2015.

4. Mojave Desert Air Quality Management District Rule 1159, “Stationary Gas 

Turbines,” as amended September 29, 2009.

5. Yolo-Solano Air Quality Management District Rule 2.34, “Stationary Gas 

Turbines,” as amended November 12, 2014.

6. “Alternative Control Techniques Document – NOx Emissions from Stationary Gas 

Turbines,” (EPA-453/R-93-007), Emissions Standards Division, EPA OAQPS, 

January 1993.

7. “Restatement and Update of EPA’s SSM Policy Applicable to SIPs,” 80 FR 33839, 

June 12, 2015.