Air Expertise Colorado, LLC 

303.670.0515

mbarrett@airexpertisecolorado.com

December 8, 2015

Janet McCabe

Acting Assistant Administrator

US EPA 

District of Columbia

Shaun McGrath

Administrator

US EPA - Region 8 

Denver

Re: Martin Drake Plant Causes Extensive and Severe Nonattainment Areas - PM2.5, NO2 and SO2

Dear Administrators:

I am an air quality scientist and a licensed professional engineer that has been applying US EPArecommended pollutant dispersion models to large electrical generating units, manufacturing and 

transportation sources for over two decades on behalf of municipalities, private industry, citizen 

stakeholder, and environmental advocacy organizations. I have served as an air quality expert 

within proceedings before state energy facility licensing boards,

1

state and county courts and 

commissions,

2

air quality and environmental advisory boards,

3 within litigation and air quality 

rulemaking proceedings,

4

in Maryland, Massachusetts, Michigan, Virginia and Colorado. 

I report here on the procedures and results of an ambient air quality analysis that evaluates the 

impacts of pollutants from the Martin Drake Power Plant, within public areas in Colorado 

Springs, with respect to short-term National Ambient Air Quality Standards (NAAQS) for 

PM2.5, NO2 and SO2

5, 6,7

 This analysis uses the recommendations of US EPA’s TAD (described 

herein) to calculate the historical impacts of the Martin Drake plant using the facility’s actual 

 

1 Before Massachusetts Energy Facilities Siting Board, 2009, on behalf of BillericaWatchers.

2 Before Virginia State Court on behalf of City of Alexandria; before Harford County Peoples’ Court on behalf of 

River Hills Club; before county commissioners for Ludington, Manistee and Traverse City on behalf of West Bay 

Exploration and Omimex Energy; 1999 – 2001. 

3 Before Virginia Air Pollution Control Board on behalf of City of Alexandria, 2005 – 2008 and before Michigan 

Environmental Science Board on behalf of Michigan Oil and Gas Association; 1999.

4 As appointed member of PM2.5 Implementation Board, Virginia Department of Environmental Quality, 2007-2008; 

before Maryland legislators for coal combustion flyash rulemaking on behalf of Environment Maryland; written 

testimony on behalf of Earth Justice in Colorado oil and gas rulemaking, 2014. 

5

“National Ambient Air Quality Standards for Fine Particulate Matter; Final Rule,” 40 CFR Parts 50, 51 and 52, et. 

al. Federal Register, January 15, 2013, at http://www.gpo.gov/fdsys/pkg/FR-2013-01-15/pdf/2012-30946.pdf.

6

“Primary National Ambient Air Quality Standard for Nitrogen Dioxide; Final Rule,” 40 CFR Parts 50 and 58, 

Federal Register, February 9, 2010, at http://www3.epa.gov/ttn/naaqs/standards/nox/fr/20100209.pdf. 

7

“Primary National Ambient Air Quality Standard for Sulfur Dioxide; Final Rule,” 40 CFR Parts 50, 53 and 58, 

Federal Register, June 22, 2010, at http://www3.epa.gov/ttn/naaqs/standards/so2/fr/20100622.pdf.
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 2 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

emissions and operational timeline – in essence, to create SO2 impacts that monitors would see 

had they been in place at all locations to which the public has access around the plant. 

Contrary to the belief that their inaction suggests city and state officials hold,8the NAAQS are 

not abstruse benchmarks stipulated in order to inhibit power production. Instead, as you know, 

NAAQS are derived by the judgement of health and medical experts based on their review of 

studies and observations of health effects that occur in response to exposure to these air 

pollutants. NAAQS are approximately equivalent to the maximum levels of pollutants that can 

occur in ambient air, before health effects start to occur in exposed individuals, with a margin of 

safety included. NAAQS include a margin of safety, i.e., the level is made more stringent, to 

address, as US EPA describes, the “uncertainties associated with inconclusive scientific and 

technical information available at the time of standard setting...” and to “provide a reasonable 

degree of protection against hazards that research has not yet identified.”9

Using procedures recommended by US EPA, I find that the impacts in public areas from the 

Martin Drake Power Plant’s three stacks exceed the NAAQS for SO2, NO2 and PM2.5, in 

extended areas at egregious levels. These results occur even in the absence of consideration of 

impacts from all of the Martin Drake’s sources and from other regional and nearby sources, 

including the significant contributions by the adjacent interstate highway and its associated high 

volumes of mobile sources. 

Given the severity and extent of these areas of nonattainment: a) at levels that likely overwhelm 

the margin of safety that each NAAQS include; b) that derive from methods that err on the side 

of underestimation of actual impacts; and c) in which multi-pollutant exposure in excess of the 

NAAQS overlaps spatially and temporally, it is extremely likely and probable that citizens 

working and living around the Martin Drake have experienced for decades, and continue to 

experience, health effects from their chronic exposure to the Martin Drake plant’s pollutants. 

Background -- Multiple Previous Air Quality Impact Analyses show Nonattainment

The Martin Drake is a 278 MW coal-fired electrical generating station in a highly urbanized area 

of Colorado Springs. Residential areas and high density commercial districts line the plant 

boundary to the southeast and northeast, respectively. The facility’s unfenced and uncovered 

coal pile and coal processing operations lie between the plant and the interstate highway to the 

 

8 Modeled results showing violations of the NAAQS were reported within separate independent engineering 

analyses to City Council (a body that also acts as the Board of the Colorado Springs Utilities) starting in 2012, and 

within hearing comments and reports to City Council in 2013 and 2014. 

9

Integrated Science Assessments (ISA) Legislative Requirements, at 

http://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=202463&CFID=51886408&CFTOKEN=78300088.
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 3 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

west (I-25). This interstate highway also separates the plant from additional residential and light 

industrial areas to the west. 

Each of three boilers (Boilers 5, 6 and 7) emits through a dedicated stack, with heights of 200 

feet for Boilers 5 and 6 and 250 feet for Boiler 7. 10 These boilers were placed in service 53, 47, 

and 41 years ago, respectively. Table 1 presents allowed boiler heat input ratings and permitted 

emission limits, as presented within the facility’s expired Title V (operating) permit. 11 Although 

the operating permit which stipulates these emission limits has been expired for over eight years, 

in contravention of state regulations, no renewed permit limits have been issued for the plant.12

A previous analysis of air quality by Air Expertise Colorado, LLC (AEC) used these maximum 

allowable emission rates for SO2 within an ambient air quality analysis (included with this 

submittal as Attachment 1). These results were presented in September, 2013 to state (i.e., Air 

Pollution Control Division) and City of Colorado Springs’ officials. Results show widespread 

areas of nonattainment of the SO2 1-hour NAAQS around the plant.13 Air quality compliance 

demonstrations by another licensed engineering firm, i.e., Wingra Engineering, also show severe 

and extended areas of nonattainment.14 One of these studies was presented to City of Colorado 

Springs and APCD officials in late 2012 and early 2013, respectively. Wingra Engineering’s 

most recent analysis,15 which studied impacts using forthcoming changes at the plant, was 

presented to city and state officials in mid-2015. To summarize, all air quality analyses of the 

Martin Drake plant, including the analysis reported herein, all conducted by engineering 

professionals using US EPA guidelines and procedures, show SO2 nonattainment in Colorado 

Springs for a full range of actual, potential and forthcoming emission scenarios. 

 

10 From Martin Drake Plant entries within ‘Stack Flue’ worksheet within “EnviroEquipY2012” spreadsheet; from 

EIA860 database.

11 Colorado Department of Public Health and Environment, Operating Permit, Colorado Springs Utilities Martin 

Drake Power Plant, Operating Permit no. 95OPEP107, Expiration Date Oct. 30, 2007. Boilers 5, 6 and 7 were

placed in service in 1962, 1968, and 1974, respectively. 

12 Department of Public Health and Environment, Air Quality Control Commission, Regulation no. 3, Stationary 

Source Permitting and Air Pollution Emission Notice Requirements, Section III.B.6 states that “[e]ach source 

subject to an operating permit shall submit an application for renewal of the operating permit at least twelve months, 

but not more than eighteen months, prior to expiration of the operating permit.”

13 Letter to Interim Director Karin McGowan, September 23, 2013. 

14“Martin Drake Power Plant – Colorado Springs, Colorado – Sierra Club Evaluation of Compliance with 1-hour 

SO2 NAAQS, October 4, 2012, S. Klafka, P.E., Wingra Engineering, Madison. 

http://content.sierraclub.org/coal/sites/content.sierraclub.org.coal/files/Evaluation%20of%20Compliance%20with%

20the%201-hour%20NAAQS%20for%20SO2%20-%20Martin%20Drake%20CO%20DRAFT,4oct12.pdf.

15 “Martin Drake Power Plant, Colorado Springs, Colorado, Evaluation of Compliance with the 1-hour NAAQS for 

SO2,” August 5, 2015, by S. Klafka, P.E., Wingra Engineering, S.C., Madison. 
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 4 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

Current Analysis – Actual Emissions and Operations Also Show Historical Nonattainment

of SO2 NAAQS caused by Martin Drake

During the period of 2011 through 2013, the Martin Drake plant emitted 15,031 tons of SO2 to

the ambient air of Colorado Springs.16 Scientific evidence links short-term exposures to SO2

concentrations (for duration exposures as short as 5 minutes) with a range of adverse respiratory 

effects, including bronchoconstriction and increased asthma symptoms. About one in every 

twelve adults, and one in every ten children in the US are asthmatic, 17 and asthmatics with 

increased rates of ventilation (e.g., while exercising or playing) are particularly affected by 

exposure to SO2. Studies also show a connection between short-term exposure to SO2

concentrations and an increase in the number of visits to hospital emergency departments and 

hospital admissions for respiratory illnesses, particularly among children, the elderly, and 

asthmatics.18

This current analysis adds to the studies of the impacts of the Martin Drake plant, and follows 

guidelines released by US EPA in early 2014 for analyses that assess nonattainment status for the 

2010 1-hour SO2 NAAQS,

19 i.e., the “SO2 NAAQS Designation Modeling Technical Assistance 

Document (or TAD). Accordingly, this analysis uses AERMOD to simulate impacts using the 

plant’s actual timeline of emissions and operating characteristics, in order to reproduce and 

assess how the actual historical impacts of SO2 from the plant complied with the 1-hour SO2

NAAQS. 

 

16 US EPA Air Markets data downloaded for Martin Drake; epa.gov/ampd.

17 http://www.aaaai.org/about-the-aaaai/newsroom/asthma-statistics.aspx.

18 http://www3.epa.gov/airquality/sulfurdioxide/health.html.

19 “Sulfur Dioxide (SO2) National Ambient Air Quality Standards Designations Modeling Technical Assistance 

Document, Draft, December 2013; released in early 2014.

Blr MMBtu/HRlb/mmbtu lb/hr ton/yr gr/sec lb/mmbtu lb/hr gr/sec lb/mmbtu lb/hr gr/sec lb/ton lb/hr gr/sec

5 548 1.2 657.6 2,880 82.9 0.46 252.1 31.8 0.1 54.8 6.9 0.5 16.3 2.06

6 861 1.2 1033.2 4,525 130.3 0.46 396.1 49.9 0.1 86.1 10.9 0.5 25.6 3.23

7 1336 1.2 1603.2 7,022 202.2 0.46 614.6 77.5 0.1 133.6 16.8 0.5 39.8 5.01

NOTES:

2. Assumes coal heating value = 8400 Btu per lb, or 16.8 MMBtu per ton.

1. All allowable emission rates from "Air Pollution Control Division, Colorado Operating Permit, Permit #950PEP107," see 2. Coal Firing of 

Boilers, pp. 13-14.

Table 1 - Maximum Allowable Emission Rates of Three Boilers at Martin Drake Power Plant. 

SO2 NOx PM10/2.5 CO
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 5 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

Table 2 presents stack characteristics for each boiler as reported by the US Energy Information 

Administration,

20 and stack flow and temperatures for each of mininum, mid and maximum 

loads that derive from results of Relative Accuracy Test Audits (RATAs) at the plant in mid2013.

21

 In order to reproduce an emissions and operational timeline for the facility and each 

boiler (i.e., hourly emission rates and stack velocity and temperatures), US EPA Air Markets 

hourly data were accessed for SO2 and NOx emission rates and heat input rates for each boiler for 

years 2011 through 2013 (as derived from in-stack monitors). Best-fit relationships for each of 

velocity and temperature as a function of load were formed using RATA observations; hourly 

load levels were then used within these best-fit relationships to calculate actual hourly velocities 

and temperatures for each boiler, for each hour of 2011 through 2013. These hourly records of 

emission rate, temperature and velocity were included within the file ’HOUREMIS’ within the 

AERMOD input run stream. 

Meteorological data derive from National Weather Service observations at the Colorado Springs 

Municipal Airport, approximately six mile to east of the plant. These data include ASOS 

observations, and accordingly the pre-processor AERMINUTE was applied prior to AERMET. 

Dimensions of downwash parameters for the Martin Drake were calculated using the BPIPPRIME algorithms. Plant layout was determined using Google Earth images; boiler building 

heights derive from architectural drawings relayed by Colorado Springs Utilities.

22

 To iterate, all 

procedures used in this analysis conform to the US EPA’s TAD recommendations for these types 

of analyses, including:

 

20 2012 Form EIA-860 Data - Schedule 6, 'Stack and Flue Data.’

21 Airtech, Report on the Relative Accuracy Test Audits, Report Dates of July 1, 2013; June 28, 2013; and June 27, 

2013 for Units 5, 6 and 7.

22 Files relayed on August 28, 2015 in response to Colorado Open Records request, by J. Butler of CSU, including 

“69-4-AR-5.JPEG” showing boiler building elevations.

Area 

(sq.ft)

Vel, 

mps Temp, K Eff. Dia, m

Area 

(sq.ft)

Vel, 

mps Temp, K Eff. Dia, m

Area 

(sq.ft) Vel, mps Temp, K

Eff. Dia, 

m

88.0 12.32 433 3.226 124.0 12.59 429 3.830 177.0 13.48 414 4.576

88.0 8.84 422 3.226 124.0 10.01 419 3.830 177.0 11.26 403 4.576

88.0 7.01 409 3.226 124.0 8.33 403 3.830 177.0 8.02 386 4.576

Table 2 - Velocity and Diameter Calculated Using EIA 860 Reports and Temp and Velocity for Three Load 

Points From Relative Accuracy Test Reports

UNIT 5 UNIT 6 UNIT 7
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 6 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

- Application of the preprocessor AERSURFACE to determine albedo, surface roughness 

and Bowen ratio around the meteorological observation site;

- The urban option with associated current population assignment to reflect the urban and 

surface heating characteristics around the power plant site;

- Terrain characterization determined by AERMAP using USGS National Elevation 

Database information for the area.

Figure 1 shows contours of the 4th highest daily 1-hour maximum for the years 2011 through 

2013. Shaded areas that exceed the NAAQS encompass approximately two to three square 

miles, in an area of the city where population density is high. 

 
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 7 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

State Responds to Engineering Reports of SO2 Nonattainment by Placement of One 

Monitor – CSU Then Requests Assistance from Professional Meteorologists to Forecast

High Impact Conditions

Following the public release, in October, 2012 of the Wingra Engineering study showing severe 

and widespread nonattainment of the NAAQS in Colorado Springs from the Martin Drake’s SO2

emissions, an SO2 monitor was located by the Colorado Department of Public Health and 

Environment approximately one kilometer distant from the northwestern edge of the plant’s 

boundary. In response to the September, 2013 letter by AEC showing widespread exceedance of 

the SO2 ambient air quality standard using the facility’s permitted rates, Deputy Director 

Kaufmann wrote, in November, 2013, that:

“as required by federal law, CDPHE has installed an SO2 monitor in the area to 

directly measure ambient SO2 concentrations....since the beginning of 2013, 

[t]herefore there is not the requisite three years [sic] worth of data necessary to 

evaluate whether the area is complying with the NAAQS...the actual monitored 

values do not support the conclusion that the area is violating the SO2 NAAQS.” 

Then, in correspondence dated December 31, 2013, Colorado Springs Utilities’ air quality

consultants (i.e., as employees of AECOM) wrote to Vicki Card, Environmental Services 

Supervisor of Colorado Springs Utilities, stating that:

“we understand that CSU would like to discuss the feasibility of identifying, in 

advance, meteorological conditions that may lead to elevated ambient SO2

concentrations. Operations during these predicted events would be altered to 

include switching one or more coal-fired units to natural gas to address the 

compliance requirements. Generally, a weather forecasting and/or dispersion 

modeling predictive method has not been allowed for demonstrating compliance, 

but we will discuss any of your past discussions with CDPHE or US EPA 

regarding this approach.”23

Indeed, dispersion method techniques, in which meteorological conditions are predicted and 

plant operations are changed to reduce impacts, are prohibited by the Clean Air Act.24 The 

actions of APCD and CSU (which the statements of their consultant indicate may have been

coordinated) exemplify why these dispersion techniques are prohibited: Deputy Director 

Kauffmann attempts to persuade that the single SO2 monitor is sufficient to characterize the 

attainment status of the entire Colorado Springs area, while Colorado Springs Utilities asks for 

 

23 B. Macdonald, Ph.D.; P. McKean, CCM; and S. Duncan of AECOM to V. Card, December 31, 2013. Included 

within files relayed to M. Barrett of AEC from CSU in response to Colorado Open Records Act request. 

24 40 CFR 51.166 Prevention of Significant Deterioration, “...the degree of emission limitation required for control 

of any air pollutant under the plan shall not be affected in any manner by ...2) any other dispersion technique...”
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 8 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

guidance from their professional meteorological consultant on how to predict meteorological 

conditions that show high impacts. 

This shows an unabashed interest by this owner/operator and the agency in misleading the public 

away from a full and open accounting of the plant’s potential worst case impacts. What happens 

for the majority of the hours when the wind direction and conditions are forecast to send the 

plume toward the many quadrants and sectors around the plant where there is no monitor? 

Such a potential for deceit and unlimited exceedance of impacts is why a permit that protects 

against violations of health-based standards for all potential weather patterns and conditions and 

emissions is necessary. Accordingly, the Clean Air Act prescribes that NAAQS-based emissions 

limits for major sources be set using dispersion models that calculate those protective limits for 

the widest possible range of all meteorological conditions and maximum potential emissions. 

The US EPA Guideline on Air Quality Models states that use of a representative five-year

meteorological data set assures that the greatest potential range of actual conditions are 

incorporated in the analysis.25 In essence, the results of a modeled approach assure against 

violations of health-based standards for the potential convergence of worst-case events. 

Current Analysis - NO2 Impacts by Martin Drake Also Show Nonattainment 

US EPA reports that short-term NO2 exposures (ranging from 30 minutes to 24 hours) are linked 

to adverse respiratory effects including airway inflammation in healthy people and increased 

respiratory symptoms in people with asthma. Studies also show a connection between breathing 

elevated short-term NO2 concentrations, and increased visits to emergency departments and 

hospital admissions for respiratory issues like asthma.

NO2 concentrations near roadways are appreciably higher than those measured at monitors in a 

regional network. These high concentrations of NO2 are especially concerning for residents that 

live adjacent to roadways.26

The Martin Drake plant is also a large source of NOx emissions (that convert to NO2 in the 

ambient air). During the period of 2011 through 2013, the Martin Drake plant emitted 11,477 

tons of NOx to the ambient air of Colorado Springs. The Martin Drake plant is currently 

undergoing the implementation of a pollution control project at each of Boilers 6 and 7 to reduce 

SO2 emissions, i.e., the Neumann Systems Group technology, in accordance with the facility’s

 

25 “US EPA Guideline on Air Quality Models,” Federal Register, November 9, 2005, page 68244 reports on a study 

that “indicated that the variability of model estimates due to the meteorological data input was adequately reduced if 

a 5-year period of record of meteorological input was used.” Referenced study is “Burton, C.S., T.E. Stoeckenius 

and J.P. Nordin, 1983. The Temporal Representativeness of Short-Term Meteorological Data Sets: Implications for 

Air Quality Impact Assessments. Systems Applications, Inc., San Rafael, CA. (Docket No. A-80–46, II-G–11).

26 http://www3.epa.gov/airquality/nitrogenoxides/health.html.
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 9 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

requirements to meet regional haze emission standards.27 This pollution control project will 

reduce flue gas temperatures, which in turn will lead to reduced plume buoyancy and higher 

ground-based impacts for pollutants that are not being controlled. Accordingly, the pollutants 

for which the SO2 control project is expected to increase ground-based impacts from the Martin 

Drake plant include NO2, PM2.5, CO and a wide variety of hazardous air pollutants. Although 

the contract for this project was entered into during the 2011 to 2012 timeframe with the 

provider, long after after the 1-hour 2010 SO2 NAAQS was finalized, no analysis of the project’s 

ability to meet the 1-hour 2010 SO2 standard was requested of the provider by city officials.28

The Clean Air Act allows the inclusion of dispersion techniques for pollutants for which a 

control project is contemporaneously implemented. For other non-reduced pollutants, any credit

for reduction in pollutant impacts from dispersion techniques such as flue gas reheat are not 

allowed within compliance demonstrations. Accordingly, for NO2 and PM2.5 for which no 

pollution control project is being implemented at the plant, this analysis uses the flue gas 

temperature that the cooling by the Neumann Systems Group technology incurs. While

observations of these post-Neumann Systems Group implementation stack temperatures are not 

yet available, industry reports of this type of control technology at coal-fired boilers suggest that 

flue gas temperatures may drop significantly, for example, to approximately 125 to 160 deg. F. 

US EPA’s predictions show that because of flue gas temperature reductions, desulfurization 

projects at coal-fired power plants can increase ground-based impacts of NO2 by up to 160% 

over pre-SO2 control project implementation.

29

This analysis uses an estimate for the reduction in flue gas temperature (with a minimum of 201 

deg. F) that very likely errs on the side of overestimating the stack gas temperature30 and 

 

27 Letter, Michael Brady, P.E., Technical Services Supervisor of Colorado Springs Utilities to Kirsten King, 

Stationary Sources Program Manager, Air Pollution Control Division, Colorado Department of Public Health and 

Environment, June 2, 2010. Emission limit required for Boilers no. 6 and 7 are stated to be 0.15 lb per MMBtu on a 

30-day rolling basis. 

28 Multiple requests for an analysis to assess the effect of the Neumann Systems Group technology on the capability 

of the Martin Drake to meet all NAAQS were made within public comments before Colorado Springs City 

Council/Utilities Board in 2013 and 2014. 

29 A portion of the water in the slurry is evaporated and the waste gas stream becomes saturated with water vapor. 

For example, at Pubic Service Company’s Cherokee station, installation of SO2 scrubbers reduced flue temperatures 

to approximately 160 degrees (from “Retrofitting Lime Spray Dryers at Public Service Company of Colorado,” R. 

Telesz; J. Doyle of Babcock and Wilcox Company and R. Larson of Utility Engineering, presented at POWER-GEN 

International 2000, Orlando, November 14-16, 2000). See also “Stack Gas Reheat Evaluation,” EPA-600, US EPA’s 

Industrial Environmental Research Laboratory, Research Triangle Park, March, 1980, which presents predictions of 

maximum ground-based impacts as a function of un-scrubbed and scrubbed stack gases. See also US EPA’s Air 

Pollution Control Technology Fact Sheet, EPA-452/F-03-034, Flue Gas Desulfurization (FGD) - Wet, Spray Dry, 

and Dry Scrubbers, at www.epa.gov/ttn/catc, in which the energy, i.e., heat, available for steam production is 

reduced.

30 This analysis assumes a post-Neumann System Group temperature in the stack of 201 deg. F. 
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 10 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

therefore underestimates impacts of NO2. Using this assumption, a historical timeline of NOx

emissions was formed, using updated best fit relationships between temperature, velocity and 

load. NO2 impacts from the plant were predicted using the 2011-2013 hourly timeline of NOx 

emissions and boiler operating conditions, but reduced flue gas temperatures are used to reflect 

the Neumann System Group project’s implementation. 

Figure 2 shows these results (assuming Tier 1 assumptions regarding NOx to NO2 conversion).

31

 

Note that these results do not include background levels of NO2, nor do they include the 

contribution to NO2 impacts by the close-by and heavily-travelled interstate. Annual average 

daily traffic volumes along this section of highway exceed 110,000 vehicles per day, and 6% to 

8% of those volumes are trucks.

32

 These interstate sections also show very high volume-tocapacity ratios, suggesting conditions of congestion, which were shown to lead to NO2 and/or 

PM2.5 NAAQS exceedances on adjoining residential areas along another highly-travelled 

interstate.

33

 The very close distances associated between the plant and interstate suggest that 

contributions by mobile sources will be significant in exactly those areas that are already heavily 

impacted, at levels exceeding the NAAQS, from the plant’s NO2 emissions. 

 

31 Full conversion of NOx to NO2. 

32 Colorado DOT Online Transportation Information System (http://dtdapps.coloradodot.info/otis) for the sections of 

I25 adjacent to the Martin Drake Power Plant.

33 For another high-volume interstate, an AERMOD-based analysis of air quality impacts showed that NO2 and 

PM2.5 NAAQS were exceeded within adjacent residential communities. See “I-95 HOV/HOT LANES Northern 

Terminus: Air Quality Impacts on Adjacent and Nearby Communities in Fairfax County, Virginia,” submitted to J. 

Britton of Schnader, Harrison Segal & Lewis, LLP, Washington, DC 20001 and Concerned Residents of Overlook 

LLC, Fairfax County, December, 2012, by AEC. Also presented to Virginia Department of Transportation.
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 11 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

 

Current Analysis –Martin Drake causes Nonattainment by its PM2.5 Emissions 

Coal-fired power plants release significantly more particulate pollution than do other fossil-fuel 

plants, and a large fraction of that particulate pollution is PM2.5. These tiny particles, too small 

to see, are inhaled deeper into parts of the lungs that are more vulnerable to injury, potentially 

causing an array of health problems, including immune system suppression; cancer; and 

cardiovascular disease. Population subgroups that are most at risk from exposure to PM2.5 are 

active children; the elderly; and all who are active outdoors. 34 

 

34 http://www3.epa.gov/pmdesignations/faq.htm. 
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 12 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

For the period of 2011 through 2013, the Martin Drake plant emitted approximately 3,700 tons 

of particulate matter from its boiler stacks, a large fraction of that in the fine range 35 (this amount 

does not reflect any of the particulate matter emissions from the multiple other non-boiler 

sources at the Martin Drake plant – see below). The impacts of PM2.5 were calculated here using 

the Martin Drake plant’s allowable emission rates for all three boilers, emitted according to the 

hourly operational timeline for the years 2011 through 2013 (as also used in the SO2 and NOx

analyses). Note that multiple other PM 2.5 sources at the facility were not included in the analysis 

to date. Numerous additional sources around the facility are expected to emit PM2.5 and 

consequently to add to PM2.5 impacts at offsite facilities. Additional contributions to PM2.5 in 

areas around the plant that derive from the plant’s operation include: 

- Fugitive emissions from coal-loaded railcars as they enter the site and remain parked, 

with no covers;

- Fugitive emissions released as coal-loaded railcars are dumped at coal transfer sites;

- Fugitive emissions produced by wind as it moves over the uncovered and uncontrolled 

coal yard;

- Fugitive emissions from material handling processes that move coal from the yard to the 

coal conveyor;

- Fugitive emissions from the coal conveyor and coal pulverizer;

- Stack emissions released from vent points on the coal combustion byproducts (CCBs) 

silos;

- The fugitive emissions from loading CCBs from the silos to the trucks that bring CCBs to 

offsite locations;

- Fugitive roadway emissions from these CCB-carrying and sorbent-carrying trucks along 

the site’s roadways;

- Fugitive emissions from the unloading of sorbent-carrying trucks into sorbent silos;

- Stack emissions released from vent points on the sorbent-storage silos;

- High volume truck and other mobile source traffic on the close-by interstate;

- Opacity exceedances that may have resulted in emission rates of PM2.5 from the plant’s 

stack that exceed the allowed emission limit by multiple times;

- Contributions to PM2.5 from SO2 and NOx emissions that combine to form particulate 

matter in ambient air. 

 

35 Using EPA Air Markets data for the years 2011 through 2013, for each boiler’s hourly heat input rate and the 

allowable PM emissions rate. Note that no quantitative continuous measure of PM2.5 or PM10 emissions is in place 

at the Martin Drake. Opacity excursions can lead to multiple times the allowed rate of PM emissions at coal-fired 

power plants. 
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 13 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

Currently there are no continuous emissions monitors for PM in use in the Martin Drake’s stacks, 

even though these instruments are used at many other coal-fired power plants.36 While opacity is 

a poor quantitative indicator of the amount of particulate in the flue gas stream, it is currently the 

only surrogate by which particulate emission rates can be continuously evaluated at the Martin 

Drake. 

The Air Pollution Control Division allows exceedances of opacity from the Martin Drake for

common operational situations, including boiler startup and load changes. More specifically, the 

Martin Drake’s stacks’ maximum opacity level of 20% can increase up to 30% for a period or 

periods aggregating up to six minutes in any consecutive 60 minutes,

37 during these specific 

operational conditions, without violating its opacity requirements. 

For this plant, these opacity excursions may translate into PM emissions that significantly exceed 

the allowed PM rates. For example, observations of PM emissions as a function of opacity at 

another coal-fired boiler show that an opacity level of 30% equates to an emission rate of 0.3 lb 

per MMBtu, which represents three times the allowed level for the Martin Drake stacks, and 

depending on the frequency of load changes and startup, may occur for approximately 10% of 

boiler operation.

38

 

Note that the results of Figure 3 depend on the unlikely assumption that the stack emission rates 

for PM2.5 never exceeded the facility PM emissions limit. Given that there may have been

multiple excursions to high opacity levels at the Martin Drake plant during this operational 

timeline, the results of Figure 3 likely err on the side of underestimation of PM 2.5 impacts. 

 

36 American Electric Power Company and Southwestern Power Company have agreed to install PM CEMS, and 30 

other existing coal-fired power plants have committed to the use of PM CEMs; from “Petition Requesting that the 

Administrator Object to Issuance of the Proposed Title V Operating Permit for the Wansley Power Plant -- Before 

the Administrator – United States Environmental Protection Agency;” http://greenlaw.org/pdf/WansleyPetition.pdf.

37 Colorado Department of Public Health and Environment, Operating Permit, Colorado Springs Utilities Martin 

Drake Power Plant, Operating Permit no. 95OPEP107, expiration Date Oct. 30, 2007. 

38 Observations by Electric Power Research Institute as reported within “Particulate Matter from Maryland Power 

Plants,” Prepared for Environment Maryland Research & Policy Center by E. Riddlington, Frontier Group; M. 

Barrett, Aero Engineering Services; and B. Heavner, Environment Maryland Research & Policy Center; June, 2007. 
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 14 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

 

Neumann Systems Group Project Appears to Significantly Exceed Cost of Similar SO2 

Control Projects in Colorado yet its Effects on Air Quality in Colorado Springs are 

Unknown

The Neumann Systems Group technology was approved by the APCD to meet the Best 

Available Retrofit Technology requirements of Colorado’s Regional Haze State Implementation 

Plan. Colorado’s Regional Haze Plan39 states that:

“Best Available Retrofit Technology (BART) [m]eans an emission limitation based 

on the degree of reduction achievable through the application of the best system of 

continuous emission reduction for each pollutant that is emitted by an existing 

stationary facility. The emission limitation must be established, on a case-by-case 

 

39 https://www.colorado.gov/pacific/sites/default/files/AP_PO_Regional-Haze-Plan-Part-F-Best-Available-RetrofitTechnology_0.pdf.
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 15 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

basis, taking into consideration the technology available, the costs of compliance,

the energy and non-air quality environmental impacts of compliance, any pollution 

control equipment in use or in existence at the source or unit, the remaining useful 

life of the source or unit, and the degree of improvement in visibility which may 

reasonably be anticipated to result from the use of such technology.”

Note that emphasis has been added showing that the cost of compliance is one of the key 

elements in the determination of which technology meets the definition of BART. 

Consequently, approval of BART by the APCD must rely on its cost effectiveness. Currently, the 

total installed cost of the Neumann Systems Group project is reported to be close to $200 

million;

40 this figure includes $25 to $27.3 million to test the Neumann Systems Group pilot 

project.41 As a publicly owned utility, these costs will be borne by Colorado Springs Utilities’

ratepayers, i.e., the citizens of the Colorado Springs metropolitan area. Even though requested 

by citizens, an analysis of how the $200 million Neumann Systems Group technology will affect 

the ambient air in Colorado Springs has never been performed by either Colorado Spring 

Utilities or by the Neumann Systems Group. Nor has APCD required that such an analysis be

performed showing the effects of this $200 million project on the air quality around the plant, 

despite this plant’s location within the urban core of the second-most populous city in 

Colorado.42

Also concerning is that the cost of the Neumann Systems Group technology appears exorbitant 

when compared to the costs of SO2 control projects implemented at other Colorado coal-fired 

electrical generating units. Assuming an annual SO2 reduction rate of 95% on Boilers 6 and 7, 

and an 80% operational capacity, the Neumann Systems Group technology will remove

approximately 4,750 tons of SO2 for the plant, annually.

43 Therefore, the cost efficiency, i.e., 

the total installed cost of the Neumann Systems Group control system as a function of the SO2 

reduction that the project will achieve annually, equals $42,105 per ton. 

 

40 http://gazette.com/colorado-springs-utilities-works-to-clear-the-air-on-scrubber-project-cost/article/1548703, 

reports the cost of the Neumann Systems Group project at $170 million. With the added cost of the pilot test 

project, the total cost is approximately $200 million. 

41 Letter, B. McCormick, P.E., Chief Energy Services Officer of Colorado Springs Utilities, to Dr. D. Neumann of 

Neumann Systems Group, Inc., March 18, 2011 states $25 million, while two other documents obtained through a 

Colorado Open Records Act request by L. Weise state $27.3 million for the Neumann test pilot program (2011-11 

Neumann Reclass Adjustment Summary and CSU Bond Offering 2012). 

42 Population of Colorado Springs reported as 445,830; https://en.wikipedia.org/wiki/Colorado_Springs,_Colorado.

43 Assuming a 95% target rate for SO2 removal on Units 6 and 7, and using an average annual rate for both Boilers 6 

and 7 of 5,000 tons (from 15,031 tons of SO2 actually emitted from 6 and 7 in the years 2011 through 2013), results 

in tons of SO2 removed by the Neumann Systems Group technology of approximately 4,750 tons of SO2 for the 

plant.
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 16 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

Table 3 presents costs and controls efficiencies as reported by the US Energy Information 

Administration for coal-fired power plants in Colorado. These data show total installed capital 

costs of SO2 control projects (many of which are also likely required by the Regional Haze Plan 

requirements). An estimate for the tons per year of SO2 reduced by each project is calculated 

assuming an 80% operational capacity for each plant and using each project’s reported SO2 

control efficiency. On the basis of these public reports, when using a similar measure of cost

efficiency for these other Colorado coal-fired power plants, i.e., the total installed cost of each

SO2 control project as a function of the SO2 reduction that each project will achieve annually, the

results range from $381 to $5,854, with an average cost of $2,631 per ton44 compared to the 

Neumann Systems Group technology cost of $42,105 per ton.

On the basis of these public reports, the cost to citizens/ratepayers Colorado Springs of the 

Neumann Systems Group technology is on the order of ten or more times that which investors 

are paying at other Colorado utilities for SO2 control. Given that Regional Haze compliance at 

the Martin Drake only required that Boilers 6 and 7 reduce SO2 by approximately 60 to 80%

45

, 

and given that other utilities in Colorado had implemented cost effective solutions to reduce SO2

(several likely for the Regional Haze Plan’s requirements also), the following questions must be 

addressed for Colorado Springs’ citizens:

- Why did the APCD approve a system at the Martin Drake that did not take into account 

cost effectiveness, as required by the Regional Haze rule, when cost effective solutions 

had been implemented at other coal-fired power plants in Colorado?46 

- Given that natural gas is burned in the Boilers 6 and 7 now, if natural gas were burned in 

Boilers 6 and 7 in the future, could dry sorbent injection using trona been implemented at 

the Martin Drake (at a total installed cost that would likely have been on the order of 

between 1% to 5% of the cost of the Neumann Systems Group technology)?

- If the Neumann Systems Group is installed, will it allow the Martin Drake to show 

modeled compliance with the new 1-hour SO2 and NO2 standards and hazardous air 

pollutant standards?

These cost comparisons and issues deserve to be discussed in an open setting with regulators. 

No such opportunity for public review and comment have been extended to citizen stakeholders 

because the agency continues to allow the plant’s unfettered operation in the absence of a 

renewed operating permit.

 

44 Flue gas desulfurization manufacturers for these other Colorado coal-fired power plants are Babcock and Wilcox, 

Joy and Peabody. 

45 Air Markets reports show rates of 0.4 to 0.7 lb per MMBtu for SO2 for each of boilers 6 and 7 during 2011 

through 2013. Reduction to the SO2 rate of 0.15 lb per MMBtu requires control efficiency in the range of 60% to 

80% for the Martin Drake boilers in order to meet Regional Haze requirements.

46 The 500 MW coal-fired power plant owned by GenOn in Alexandria, Virginia used trona in a dry sorbent 

injection application for approximately a 75% SO2 reduction rate.
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 17 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

Table 3 – Summary of US Energy Information Administration Reports of Total Costs and Control 

Rates for SO2 Control Projects Installed at other Colorado Utilities (since 2000).

Due Process Denied to the Citizens of Colorado Springs by the Colorado APCD

The withholding of a draft permit of this major source from public review represents a 

significant deterioration of the right to public involvement, comment and review that the Clean 

Air Act stipulates.

47

 Citizens of Colorado Springs have for many years had no such opportunity 

 

47 Section 500 of the Clean Air Act stipulates that prior to approval of a major source’s operating permit that the 

public be given opportunity for review. Utility Name

Plant 

Name

FGD 

Status

Inservice 

Year

FGD 

Type 1

Sorbent 

Type 1

FGD 

Provider

Removal 

% of 

Sulfur

SO2 

Removed 

per Year at 

80% 

Capacity

Capital 

Cost 

Total, $ 

(x 1,000)

Capitial 

Cost 

Total, by 

SO2 

Removed 

per Year

Public Service 

Co of Colorado Comanche OP 2008 SD LA BW 90% 8,199 48,000 5,854

Public Service 

Co of Colorado Comanche OP 2008 SD LA BW 90% 8,199 48,000 5,854

Public Service 

Co of Colorado Comanche OP 2010 SD LA BW 90% 8,199 48,000 5,854

Public Service 

Co of Colorado Cherokee OP 2002 SD LA BW 90% 7,008 32,000 4,566

Public Service 

Co of Colorado Cherokee OP 2003 SD LA BW 90% 12,264 43,000 3,506

Public Service 

Co of Colorado Valmont OP 2002 SD LA BW 90% 12,264 39,000 3,180

Public Service 

Co of Colorado Arapahoe OP 2003 DP SC IH 50% 2,102 1,200 571

Public Service 

Co of Colorado Cherokee RE 2003 SP SC IH 50% 3,154 1,200 381

Notes:

SD = spray drier ytpe/dry FGD/semi-dry FGD.

DP = dry powder injection.

SP = spray type.

LA = lime and alkaline fly ash.

SC = single cyclone. Other Colorado - Average Cost Efficiency = $2,631

BW = Babcock and Wilcox.

IH = In-house design. 

OP = Operating.

RE = Retiring.
Air Expertise Colorado, LLC 

Letter to US EPA – Martin Drake Nonattainment

December 8, 2015

Page 18 of 18

303.670.0515

mbarrett@airexpertisecolorado.com

to learn of this plant’s impacts and the procedures by which they are calculated. Comments on 

the air quality impacts of the source are explicitly delineated as required information which the 

APCD must address as part of the Operating Permit renewal process. 48 Therefore, by 

withholding a draft permit from public review, the APCD averted any discussion regarding these 

unsafe impacts that both Wingra Engineering’s and AEC’s analyses describe, and allowed the 

plant to continue to operate fully without any health-based constraints.49 Other issues to which 

APCD would have had to respond within public review include: 

- How does the $200 million Neumann Systems Group project affect the plant’s ability to 

comply with the NAAQS at public areas immediately adjacent to the plant? 

- Since citizens are spending $200 million on the Neumann Systems Group project to 

contain Martin Drake’s visibility impacts in Rocky Mountain National Park (140 miles 

distant) – why can’t they learn how the Neumann Systems Group project will affect air 

quality where Colorado Springs citizens daily recreate, reside and work?

- How does the 200 million dollars spent by Colorado Springs citizens to reduce SO2

emissions using the Neumann Systems Group project, compare to the cost of SO2 control 

projects that were installed at other coal-fired electrical utility generators in Colorado?50

- Why are opacity exceedances allowed at this plant, at all, in this urban setting where 

vulnerable populations live, work and play nearby? 

- Why isn’t a much lower opacity level (i.e., 10%) required in this densely populated area?

- Why are PM CEMs not being used at this plant to assure that PM rates are not exceeded?

- How do opacity exceedances translate to higher particulate emissions at this plant where 

PM 2.5 emissions from the plant and nearby interstate already exceed NAAQS?

I thank the US EPA for addressing now these important issues that bear on the welfare of 

citizens in Colorado Springs. I will gladly relay modeling files electronically, if you wish. 

Sincerely,

Maureen Barrett, P.E.

Air Expertise Colorado, LLC

 

48 Part C, Concerning Operating Permits, Section VI, Public Participation Requirements. See VI.B.12 stating that 

“comments that are solicited on the air quality impacts of the source or modification” must be information that is 

included on the Division’s website on which the renewal notification is posted. 

49 None of the plant’s operating permit rates derive from an analysis of the plant’s impacts on the surrounding area. 

50 For the Trans Alta plant in Washington, the utility paid $190 million in capital costs to control SO2 in 2002/2003 

on two boilers. This system reduced SO2 by app. 80,000 tons per year. CSU estimates their SO2 control project cost 

as $200 million on two boilers, for a system that will reduce SO2 by app. 4,500 tons per year. 

http://www.ecy.wa.gov/programs/air/TransAlta/Final_agreement/Transalta_signed_agreement.pdf.
Attachment 1 – Under Separate Cover

Letter - AEC to Interim Deputy Director K. McGowan – September 23, 2013