September 28, 2007 

William L. Neal 

Omaha Public Power District (OPPD) 

444 South 16th Street Mall 

Omaha, Nebraska 68102 

RE: Best Available Retrofit Technology (BART) Analysis for Nebraska City Station 

Dear Mr. Neal: 

The Nebraska Department of Environmental Quality (NDEQ, Department) has begun reviewing the 

BART Analysis submitted by OPPD for Nebraska City Station (NCS), Unit 1 on August 7, 2007. At this 

time, the Department has identified several items which need to be clarified, revised, or submitted. If you 

wish to discuss these items further, please contact Sara Speser at (402) 471-2951 or via email at 

sara.speser@ndeq.state.ne.us. 

1) OPPD indicated that it is unknown if the installation of Low Nitrogen Oxide (NOx) Burners 

will trigger New Source Review (NSR) for carbon monoxide (CO), volatile organic 

compounds (VOC), or other pollutants due to changes in combustion conditions. Recently 

the Department has issued a permit in accordance with NSR for an increase in CO due to the 

installation of Low-NOx burners on a unit similar in size and type as NCS Unit 1. OPPD can 

assume that other pollutant emissions will not increase, however emissions monitoring will 

be required in order to prove that emissions have remained constant or have not increased in 

levels that exceed the significance thresholds. If emissions do increase in amounts greater 

than the significance thresholds contained in the Prevention of Significant Deterioration 

(PSD) program, OPPD would be in violation of modifying a unit without obtaining a PSD 

permit prior to commencing construction. Therefore if OPPD would prefer to complete and 

submit the appropriate materials to the Department in order for the Department to process this 

permitting action for the increase in other pollutants, the necessary materials include, but are 

not limited to, construction permit application forms, Best Available Control Technology 

(BACT) Analysis, Air Dispersion Modeling Analysis, and Additional Impacts Analysis. A 

second construction permit application fee is not required, as this information would be an 

addendum to the current permitting project. Please reference application number 07-0049 if 

additional information associated with the BART permitting action is submitted. 

2) There are several questions concerning the BART analysis for sulfur dioxide (SO2) and 

nitrogen oxides (NOx). The five basic steps of a Case-by-Case BART Analysis, as stated in 

40 CFR 51, Appendix Y, are 1) Identify all Available Retrofit Control Technologies; 2) 

Eliminate Technically Infeasible Options; 3) Evaluate Control Effectiveness of Remaining 

Control Technologies; 4) Evaluate Impacts and Document the Results, and; 5) Evaluate 

Visibility Impacts. The BART analyses submitted for SO2 and NOx lacks information 

concerning steps 2 and 3. Specifically all of the available retrofit control technologies that 

have been identified have not adequately been dismissed as being technically infeasible (i.e. 
not available and not applicable). Each control technology must be evaluated to be deemed 

technically feasible or not prior to evaluating control effectiveness and/or cost of the controls. 

3) Each pollutant should be evaluated individually with regard to the Visibility Impacts 

Analysis. OPPD evaluated four scenarios in the visibility impacts analysis. The four 

scenarios being: 1) Existing Pre-BART Control; 2) Low NOx Burner including an overfire air 

port system (LNB/OFA); 3) LNB/OFA and Spray Dryer Absorber (SDA); and 4) LNB/OFA 

+ SDA and Selective Catalytic Reactor (SCR). OPPD should have evaluated scenarios 

including installing NOx and SO2 controls separately. Therefore OPPD should evaluate a 

LNB/OFA and SCR scenario and an SCR only scenario prior to evaluating any scenarios 

where the NOx and SO2 control options are combined. 

4) The costs associated with ID Booster Fan Equipment and Electrical Modifications were 

established based on the assumption that both an SDA and SCR would be required for both 

units. These cost items should have been evaluated as if these changes would need to occur if 

only one of the two control devices were to be required. It is not appropriate to only evaluate 

the cost of the units together since the cost may decrease significantly if only one or the other 

control device would be required for BART. 

5) Complete results of the visibility impacts analysis, i.e. air dispersion modeling, was not 

submitted to the Department. It is necessary for the Department to have more information 

than the summary provided, including input files, output files, and other information in case 

this information needs to be reviewed or provided to other states or federal agencies. 

6) Some additional questions are listed below: 

• What is the remaining useful life on Unit 1’s existing burners? In other words, when 

would the existing burners on Unit 1 need to be replaced if BART was not being 

evaluated at this time? 

• How much money is expected to be recouped when the recovered metal, due to 

demolition, is sold? 

We appreciate your timely response to our questions. If clarification is needed please contact Sara Speser 

at (402) 471-2951 or via email at sara.speser@ndeq.state.ne.us. 

 Sincerely, 

 Shelley Kaderly 

 Air Quality Division Administrator