Document ID: EPA-R09-OAR-2016-0262-0005
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2016-08-01T04:00Z

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

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.

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/R-93-007, 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.
      
      	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.

      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

 "Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations," (a.k.a., Bluebook) EPA OAQPS, May 25, 1988.
 "Guidance Document for Correcting Common VOC & Other Rule Deficiencies," (a.k.a., Little Bluebook), EPA Region 9, August 21, 2001.
 Placer County Air Pollution Control District Rule 250, "Stationary Gas Turbines," as amended October 8, 2015 and submitted to EPA on March 11, 2015.
 Mojave Desert Air Quality Management District Rule 1159, "Stationary Gas Turbines," as amended September 29, 2009.
 Yolo-Solano Air Quality Management District Rule 2.34, "Stationary Gas Turbines," as amended November 12, 2014.
 "Alternative Control Techniques Document  -  NOx Emissions from Stationary Gas Turbines," (EPA-453/R-93-007), Emissions Standards Division, EPA OAQPS, January 1993.
 "Restatement and Update of EPA's SSM Policy Applicable to SIPs," 80 FR 33839, June 12, 2015.