UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8

Ref: 8P-AR
Terry O'Clair, Director Division of Air Quality Environmental Health Section North Dakota Department ofHealth 918 East Divide Avenue 1595 Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08 

# APR 20 2012

Bismarck, North Dakota 58501-1947

Dear Mr. O'Clair: RE: EPA Comments for April 10, 2012 Public Hearing on Proposed Revisions to the North Dakota Air Pollution Control Rules and State Implementation Plan

The EPA has completed a preliminary review ofthe draft revisions to the North Dakota State Implementation Plan (SIP) and Air Pollution Control Rules, as submitted by you with a letter dated February 14, 2012. Our comments and questions are detailed in Enclosure 1 to this letter. In addition, and as we have done previously. we also included comments on problematic Director's discretion concerns in the chapters noticed for the hearing. The proposed revisions listed below will not be incorporated into the North Dakota SIP. The EPA will take separate actions on them when submitted.

• Chapter 33-15-12

• Chapter 33-15-14-06 • Chapter 33-15-21 • Chapter33-15-22

• Section 33-15-23-04 Standards for Performance for New Stationary Sources Title V Permit to Operate Acid Rain Program Emission Standards for Hazardous Air Pollutants for Source Categories Major Source Permit to Operate Fees (Title V Fees)
A written response to the EPA's comments, and all other comments received, is required to meet the completeness criteria outlined in 40 CFR part 51, appendix V and must be included in the formal Governor's submittal ofthe revisions to the SIP once they are finalized. We will only come to a final conclusion regarding the adequacy ofthese North Dakota SIP revisions when we act on them through our own public notice and comment rulemaking.**·~** ) We appreciate the opportunity to provide comments for your public hearing record. 

### Ifyou have any questions on the EPA's comments, please contact me at 303-312-6416, or have your staff contact Gail Fallon at 303-312-6281.

Enclosure

cc: Tom Bachman, NDDH 

# CiJJ.

Carl Daly,

# Directo~ Air Program

2ENCLOSURE 1 EPA Comments for North Dakota's April 10, 2012 Public Hearing Director's Discretion Language We note and appreciate that you have addressed our previous Director's discretion concerns under sections 33-15-03-04.4 and 33-15-05.01.2.a(l). Other concerns, including Director's discretion issues, that we have previously commented about in parts of Chapter 33-15 ofthe North Dakota Administrative Code still remain and are detailed below. It appears that the State is not proposing to revise those parts in this action. However, ifthe State ultimately adopts its proposed revisions to 33-15, and those parts with Director's discretion are submitted by the Governor, it is likely those parts will not be approvable by EPA. We urge you to revise or remove the described sections prior to submittal. Chapter 33-15-01, General Provisions 1. 33-15-01-07. Variances. This entire section is problematic because it appears tQ make variances immediately effective upon department approval. Under the Clean Air Act, no variance should be effective until EPA approves it as a State Implementation Plan (SIP) revision pursuant to section 110 ofthe Clean Air Act. 2. 33-15-01-14. Time Schedule for Compliance. The language, "except as otherwise specified" creates the problematic Director's discretion in this provision. Chapter 33-15-03, Restriction of Emission ofVisible Air Contaminants 3. 33-15-03.03. Restrictions application to fugitive emissions. The Director's discretion language ofconcern in this section is, "

...as determined or identified by the department.

.." Chapter 33-15-05, Emissions ofParticulate Matter Restricted
4. 33-15-05-01.2.a.(3) Emission limitations. This section includes a cross-reference to section 33-15-05-04 which includes Director's discretion concerns as noted further below. 5. 33-15-05-02.2.f. Emission limitations. This section incluqes the language, "new or existing source ... shall comply

... when directed by department.

.. " and requires clarification that the source cannot avoid new source performance standards (NSPS) requirements.
6. 33-15-05-03 .2.3 .a. New trash incinerators (Design). This section includes the language, "

...department may approve an alternate design

..." Performance requirements are not specific enough to ensure that the "alternate design" would provide an equivalent to the requirement for a primary combustion chamber or zone which provides complete combustion of solid waste.

17. 33-15-05-04.1. Methods ofmeasurement. The reference method replacement includes the following problematic language: ''

...as approved by the department.

..•· 8. 33-15-05-04.1.e. Methods ofmeasurement (Method 5). This section includes the following problematic language: "

...except that smaller sampling times or volumes

...may be approved by the department." Chapter 33-15-14, Designated Air Contaminant Sources, Permit to Construct, Minor Source Permit to Operate, Title V Permit to Operate 9. 33-15-14-02. Permit to Construct and 33-15-14-03, Minor Source Permit to Operate. The problematic language is summarized below: a. -02.13 .n. Exemptions. The language is, "

...minor significance as determined by the department.

.. " b. -02.19. Amendment ofpermits. The language is in the first paragraph, "

...department may ...modify

..." and in the last paragraph with the (incorrect) cross-reference to the variance provision 33-15-01-06. c. -03.13. Portable sources. The language includes a reference to the variance provision 33-15-01-07. d. -03.16. Amendment ofpermits. The language is in the first paragraph,"

...department may modify

..." and last paragraph has the (incorrect) cross-reference to the variance provision 33-15-01-06.
I 0. 33-15-14-02.6. Permit to Construct. This section includes language we have never acted on that defines which source categories are subject to public participation requirements. We have previously discussed with the State our concerns with this section ofthe rule. SIP Section 8.3.2 Continuous Opacity Monitoring for M.R. Young Station Unit 1 Main Boiler
In addition to the above Director's discretion concerns, we have some additional comments on the alternative monitoring procedure for M.R. Young Station Unit 1. We agree that the addition ofthe wet scrubber necessitates an alternate means of demonstrating opacity compliance and that the wet scrubber will further reduce visible emissions from this unit. The draft SIP revision provides for the use ofa particulate matter (PM) continuous emission monitoring system (CEMS) instead ofthe continuous opacity monitoring system (COMS) required by 40 CFR part 51, appendix P, and a PM emission limit of0.062 lb/MMBtu to ensure compliance with the applicable 20% opacity limit under NDAC 33-15-03-01.2. As you are aware, the rules that apply to this unit for identifying an alternate procedure from the required COMS are contained in 40 CFR part 51, appendix P, section 3.9, "Alternative procedures and requirements," and section 6.0, "Special consideration." The relevant provisions of section 3.9 read as follows:

2'·In cases where States wish to utilize different, but equivalent, procedures and requirements for continuous monitoring systems, the State plan must provide a description of such alternative procedures for approval by the Administrator. Some examples of situations that may require alternatives follow:

3.9.5 {\lternative continuous monitoring systems that do not meet the spectral response requirements in Performance Specification l, appendix B ofpart 60, but adequately demonstrate a definite and consistent relationship between their measurements and the opacity measurements of a system complying with the requirements in Performance Specification 1. The State may require that such demonstration be performed for each affected facility." Similarly, section 6.0 describes conditions and requirements for the establishment ofalternative monitoring requirements and states that, "when the State exempts any source subject to this appendix by use ofthis provision from installing continuous emission monitoring systems, the State shall set forth alternative emission monitoring and reporting requirements

... to satisfy the intent ofthese regulations." According to North Dakota's analysis, the compliance assurance monitoring (CAM) plan for M. R. Young Station Unit 1 indicates that a filterable PM emission rate of0.062 lb/MMBtu corresponds to 20% opacity. We reviewed the CAM plan for this unit and the opacity and corresponding PM test data provided therein. Based on our analysis. we are concerned that the 0.062 lb/MMBtu (10-minute average) PM emission limit may sometimes correspond to an opacity value greater than 20%. We note that the data in the CAM plan, while reflecting a ''definite and consistent relationship" between PM measurements and opacity measurements, consist of a limited number of data points and reflect some variability in the correlation between PM and opacity values; i.e., sometimes opacity increased as PM levels decreased. While this variability occurred within a narrow range, we are concerned that the proposed PM limit of 0.062 lb/MMBtu lacks a sufficient safety margin to assure compliance with the opacity limit. A more detailed explanation of our analysis is provided in a separate comment section below. Based on the available data, we suggest that a 10% safety margin is warranted. Our analysis indicates that a 10% safety margin would correspond to a PM limit of0.0523 lb/MMBtu. This value should ensure compliance with the 20% opacity limit. It is our understanding that historical PM emissions have been well below this level. The State has indicated in past discussions that it believes that lowering the emission limit for the monitoring requirement will effectively make the opacity limit more stringent which is not its intent. The State has also pointed out in discussions that EPA Region S's compliance staffhas approved PM CEMS for meeting opacity requirements under NSPS and that including the 0.062 limit for the SIP revision improves upon the NSPS approval.
It is not our intent that the State should make the opacity limit more stringent. A slightly lower PM limit than the State has proposed will ensure equivalency ofmonitoring methods and compliance with the 3opacity limit as required by our regulations. Also, there are different criteria that apply here than to approval ofalternative monitoring requirements under the NSPS. Here, we rhust ensure that the proposed SIP revision meets the requirements of40 CFR part 51, appendix P. That is the purpose of these comments. EPA Analysis ofM.R. Young Station Unit 1 CAM Plan We looked at the opacity and PM relationship shown from the nine runs provided in the CAM Plan. The data set was small but normally-distributed with no outliers. The data show linear relationships with r-squared values ranging from 0.94 to 0.975. With a 20% safety margin, the PM limit would be 0.0459 lb/MMBtu. With a 10% safety margin, the PM limit would be 0.0523 lb/MMBtu. The following graph provides additional information regarding our analysis.

4EPAAnalysisofMiltonR.YoungStationUnit1,ComplianceAssuranceMonitoringPlanTestDataStackOpacityComparedtoTotalParticulateEmissionsOpacitylb/MMBTUlb/hr3.10.007415.233.40.007116.2450.010821.6111.50.030166.8311.60.027165.5914.60.0442112.9614.80.042101.4915.10.039780.2220.80.0665163.68mean11.10.030544471.53889stddev6.0924130.019942249.94652.8*'20,9•2016180.0459110.48660.0523126.38381000100'It:v=7.9486x-16.691R2=0.9401•1010.1+-----------------------------y=0.0032x-0.00530.01I:A"n-=u.;u:a0.001-i---------..-------.-------r--------..------.....0510152025•lb/MMBTU•tb/hr5