UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 8 

Ref: 8P-AR 

Terry O'Clair, Director 

Division of Air Quality 

Environmental Health Section 

North Dakota Department of Health 

918 East Divide A venue 

1595 Wynkoop Street 

DENVER, CO 80202-1129 

Phone 800-227-8917 

http://www.epa.gov/region08 

APR 2 0 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 of the 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 3 3-15-14-06 

• 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 of the revisions to the SIP once they are finalized. We will only 

come to a final conclusion regarding the adequacy of these 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. If you 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 

Air Program 

Daly, Directo~ 

2 
ENCLOSURE 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 of the 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, if the 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 of the 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 of Visible Air Contaminants 

3. 33-15-03.03. Restrictions application to fugitive emissions. The Director's discretion language 

of concern in this section is, " ... as determined or identified by the department. .. " 

Chapter 33-15-05, Emissions of Particulate 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. 3 3-15-05-03 .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. 

1 
7. 33-15-05-04.1. Methods of measurement. The reference method replacement includes the 

following problematic language: '' ... as approved by the department. .. •· 

8. 33-15-05-04.1.e. Methods of measurement (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 of permits. 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 of permits. 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 of the 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 of the 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 of a 

particulate matter (PM) continuous emission monitoring system (CEMS) instead of the continuous 

opacity monitoring system (COMS) required by 40 CFR part 51, appendix P, and a PM emission limit 

of 0.062 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 of part 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 of alternative 

monitoring requirements and states that, "when the State exempts any source subject to this appendix by 

use of this provision from installing continuous emission monitoring systems, the State shall set forth 

alternative emission monitoring and reporting requirements ... to satisfy the intent of these 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 of 0.062 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 of 0.0523 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 staff has 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 of monitoring methods and compliance with the 

3 
opacity limit as required by our regulations. Also, there are different criteria that apply here than to 

approval of alternative monitoring requirements under the NSPS. Here, we rhust ensure that the 

proposed SIP revision meets the requirements of 40 CFR part 51, appendix P. That is the purpose of 

these comments. 

EPA Analysis of M.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. 

4 
EPA Analysis of Milton R. Young Station Unit 1, Compliance Assurance Monitoring Plan Test Data 

Stack Opacity Compared to Total Particulate Emissions 

Opacity lb/MMBTU lb/hr 

3.1 0.0074 15.23 

3.4 0.0071 16.24 

5 0.0108 21.61 

11.5 0.0301 66.83 

11.6 0.0271 65.59 

14.6 0.0442 112.96 14.8 0.042 101.49 15.1 0.0397 80.22 

20.8 0.0665 163.68 

mean 11.1 0.0305444 71.53889 

std dev 6.092413 0.0199422 49.94652 

.8*'20 

,9•20 

16 

18 

0.0459 110.4866 0.0523 126.3838 

1000 

100 'It: 

v= 7.9486x-16.691 

R2 =0.9401 

• 

10 

1 

0.1 +------------------------

y = 0.0032x - 0.0053 

0.01 I :A" n- = u.;u :a 

0.001 -i---------..-------.-------r--------..

0 5 10 15 20 

• lb/MMBTU • tb/hr 

5