United States 

Environmental Protection 

Agency

Technical Development Document 

for the Final Effluent Limitations 

Guidelines and New Source 

Performance Standards for the Airport 

Deicing Category 

April 2012 

 
U.S. Environmental Protection Agency 

Office of Water (4303T) 

Engineering and Analysis Division 

1200 Pennsylvania Avenue, NW 

Washington, DC 20460 

EPA-821-R-12-005 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

i 

ACKNOWLEDGMENTS AND DISCLAIMER 

This document was prepared by the Environmental Protection Agency. Neither the United States 

Government nor any of its employees, contractors, subcontractors, or their employees makes any 

warranty, expressed or implied, or assumes any legal liability or responsibility for any third 

party’s use of or the results of such use of any information, apparatus, product, or process 

discussed in this document, or represents that its use by such a party would not infringe on 

privately owned rights. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

ii 

CONTENTS 

Page 

1. LEGAL AUTHORITY .............................................................................................................. 1

1.1 Clean Water Act ...................................................................................................... 1

1.1.1 Best Practicable Control Technology Currently Available (BPT) ............. 1

1.1.2 Best Conventional Pollutant Control Technology (BCT) ........................... 1

1.1.3 Best Available Technology Economically Achievable (BAT) ................... 1

1.1.4 New Source Performance Standards (NSPS) ............................................. 2

1.1.5 Pretreatment Standards for Existing Sources (PSES) ................................. 2

1.1.6 Pretreatment Standards for New Sources (PSNS) ...................................... 2

1.2 Effluent Guidelines Plan ......................................................................................... 3

2. APPLICABILITY AND SUBCATEGORIZATION ......................................................................... 4

2.1 Applicability of the Regulation ............................................................................... 4

2.2 Subcategorization .................................................................................................... 4

2.2.1 ADF Usage.................................................................................................. 4

2.2.2 FAA Classification...................................................................................... 5

2.2.3 Land Availability ........................................................................................ 5

2.2.4 Conclusions ................................................................................................. 5

3. DATA COLLECTION ACTIVITIES ........................................................................................... 6

3.1 Preliminary Data Summary ..................................................................................... 6

3.2 Site Visits ................................................................................................................ 6

3.3 Industry Questionnaires (Surveys) .......................................................................... 9

3.3.1 Recipient Selection and Questionnaire Distribution ................................... 9

3.3.2 Questionnaire Information Collected ........................................................ 11

3.3.3 Questionnaire Review, Coding, and Data Entry ....................................... 13

3.4 Field Sampling ...................................................................................................... 14

3.5 Permit Review ....................................................................................................... 14

3.5.1 Airport Selection for Permit Review ........................................................ 16

3.5.2 Obtaining NPDES Permits ........................................................................ 16

3.5.3 Permit Review Process ............................................................................. 16

3.6 Deicing Pad Costs ................................................................................................. 20

3.7 Industry-Submitted Data ....................................................................................... 20

3.8 Literature Reviews ................................................................................................ 22

3.8.1 Current Deicing Practices and Treatment Technologies .......................... 22

3.8.2 Current Airport Deicing Discharge Data .................................................. 23

3.8.3 Chemical Information and Environmental Impact Studies ....................... 23

3.8.4 Current Deicing Discharge Regulations ................................................... 23

3.9 Data Collected Based on Public Comments ......................................................... 24

3.9.1 EPA-Collected Data .................................................................................. 24

3.9.2 Data Submitted with Public Comments .................................................... 27

3.10 References ............................................................................................................. 27

 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

CONTENTS (Continued) 

Page 

iii 

4. OVERVIEW OF THE INDUSTRY ............................................................................................ 28

4.1 Industry Statistics .................................................................................................. 28

4.1.1 Airports ..................................................................................................... 28

4.1.2 Airlines ...................................................................................................... 32

4.2 Industry Practices .................................................................................................. 34

4.2.1 Airfield Deicing Practices ......................................................................... 34

4.2.2 Aircraft Deicing Practices ......................................................................... 35

4.2.3 Airport Deicing Stormwater Collection and Control ................................ 38

4.2.4 Pollution Prevention Practices .................................................................. 39

4.3 References ............................................................................................................. 41

5. DEICING CHEMICAL USE AND DEICING STORMWATER CHARACTERIZATION ..................... 42

5.1 Deicing Chemical Usage ....................................................................................... 42

5.1.1 Airfield Chemical Use .............................................................................. 42

5.1.2 Aircraft Chemical Use and Purchasing Patterns ....................................... 43

5.2 Deicing Stormwater Characterization ................................................................... 43

5.2.1 Airfield Deicing Chemicals and Associated Deicing Stormwater ............ 44

5.2.2 Aircraft Deicing Chemicals and Associated Deicing Stormwater ............ 44

5.3 Aircraft and Airfield Deicing Chemical Use and Associated Deicing 

Stormwater at Alaskan Airports............................................................................ 53

5.4 References ............................................................................................................. 53

6. POLLUTANTS OF CONCERN ................................................................................................ 55

6.1 Identification of Airport Deicing/Anti-icing Stormwater Pollutants .................... 55

6.2 Pollutants of Concern Selection Criteria............................................................... 61

6.3 Identification of Potential Pollutants of Concern .................................................. 61

6.4 Selection of Regulated Pollutants ......................................................................... 64

6.5 References ............................................................................................................. 66

7. COLLECTION AND TREATMENT TECHNOLOGIES APPLICABLE TO AIRPORT DEICING 

OPERATIONS ...................................................................................................................... 68

7.1 Deicing Stormwater Collection ............................................................................. 68

7.1.1 Deicing Stormwater Collection and Conveyance ..................................... 68

7.1.2 Deicing Stormwater Storage ..................................................................... 72

7.2 Treatment .............................................................................................................. 74

7.2.1 Biological Treatment ................................................................................ 74

7.2.2 Physical Separation ................................................................................... 78

7.3 Recycling .............................................................................................................. 79

7.4 Pollution Prevention and Product Substitution Practices ...................................... 80

7.5 References ............................................................................................................. 86

 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

CONTENTS (Continued) 

Page 

iv 

8. PERFORMANCE OF CONTROL AND TREATMENT SCENARIOS............................................... 88

8.1 Deicing Pad Collection ......................................................................................... 88

8.2 Plug and Pump Collection with GCV ................................................................... 88

8.3 GCV Collection .................................................................................................... 89

8.4 AFB Treatment Performance ................................................................................ 89

8.5 References ............................................................................................................. 90

9. POLLUTANT LOADINGS AND POLLUTANT LOAD REDUCTION ESTIMATES .......................... 91

9.1 Data Sources ......................................................................................................... 91

9.2 Aircraft Deicing Pollutant Loading ...................................................................... 92

9.2.1 Estimate the Amount of Applied Deicing Chemical ................................ 92

9.2.2 Calculate the Amount of Pollutant Load Associated with the Applied 

ADF......................................................................................................... 100

9.2.3 Estimate the Amount of Baseline Pollutant Load that is Discharged 

Directly ................................................................................................... 101

9.2.4 Estimate Pollutant Loading Discharges for Each ADF 

Collection/Control Scenario .................................................................... 102

9.2.5 Estimate Pollutant Loading Reductions for Each ADF 

Collection/Control Scenario .................................................................... 102

9.3 Airfield Deicing Pollutant Loading .................................................................... 107

9.3.1 Estimate the Amount of Applied Deicing Chemical .............................. 107

9.3.2 Calculate the Amount of Pollutant Load Associated with the Applied 

Chemical ................................................................................................. 112

9.3.3 Estimate the Amount of Baseline Pollutant Load that is Discharged 

Directly ................................................................................................... 113

9.3.4 Estimate Pollutant Reductions for Each EPA Collection/Control 

Scenario................................................................................................... 113

9.4 References ........................................................................................................... 115

10. TECHNOLOGY COSTS ....................................................................................................... 116

10.1 Costing Approach ............................................................................................... 116

10.2 Aircraft Deicing Costs ........................................................................................ 117

10.2.1 Overview of the ADF Collection and Treatment Airport Deicing Cost 

Model ...................................................................................................... 117

10.2.2 Airport Deicing Cost Model Equation Development ............................. 118

10.2.3 Development of Airport Deicing Cost Model Inputs ............................. 128

10.2.4 Airport Deicing Cost Model Design ....................................................... 129

10.2.5 Annualized Costs for ADF Collection and Treatment Alternatives ....... 133

10.3 Airfield Deicing Costs ........................................................................................ 137

10.3.1 Urea and Potassium Acetate Chemical Costs and Application Rates ..... 137

10.3.2 Mechanical Application Equipment and Storage of Potassium Acetate 139

 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

CONTENTS (Continued) 

Page 

v 

10.4 Other ADF-Compliance-Related Costs .............................................................. 142

10.4.1 Assessing ADF Usage from Airport Tenants ......................................... 143

10.4.2 Determination of ADF Stormwater Collection Percentage .................... 143

10.4.3 Annual ADF Collection Equipment/System Inspections ....................... 146

10.4.4 COD Monitoring of On-Site Treatment Systems ................................... 147

10.5 Summary of Annualized Costs ........................................................................... 148

10.6 References ........................................................................................................... 153

11. REGULATORY OPTIONS CONSIDERED AND SELECTED FOR BASIS OF FINAL REGULATION

......................................................................................................................................... 155

11.1 BPT and BCT ...................................................................................................... 155

11.2 BAT..................................................................................................................... 155

11.2.1 Airfield Deicing: Product Substitution of Pavement Deicers 

Containing Urea ...................................................................................... 156

11.2.2 Aircraft Deicing: ADF Collection Requirements and Effluent 

Limitations .............................................................................................. 157

11.2.3 Options Considered for Today’s Final Regulation for Identification of 

BAT for ADF Collection and Discharge Requirements ......................... 158

11.2.4 BAT Options Selection ........................................................................... 159

11.3 NSPS ................................................................................................................... 160

11.4 PSES and PSNS .................................................................................................. 162

11.5 References ........................................................................................................... 162

12. NON-WATER QUALITY IMPACTS ..................................................................................... 164

12.1 Energy Requirements .......................................................................................... 164

12.2 Air Emissions ...................................................................................................... 166

12.2.1 Emissions from GCV Collection ............................................................ 166

12.2.2 Emissions from AFB Treatment Systems ............................................... 168

12.3 Solid Waste Generation ...................................................................................... 168

12.4 Summary ............................................................................................................. 169

12.5 References ........................................................................................................... 169

13. LIMITATIONS AND STANDARDS: DATA SELECTION AND CALCULATION .......................... 171

13.1 Selected Pollutant Parameters ............................................................................. 171

13.1.1 COD ........................................................................................................ 171

13.1.2 Ammonia as Nitrogen (Ammonia) ......................................................... 171

13.2 Overview of Data Review and Selection ............................................................ 172

13.2.1 Data Selection Criteria ............................................................................ 172

13.2.2 Other Considerations in Data Selection .................................................. 174

13.3 Conventions for Modeling Multiple Data Sets from the Same Facility ............. 175

13.4 COD: Data Selected as Basis of Final Limitations ............................................. 176

13.4.1 Albany Treatment System....................................................................... 176

13.4.2 COD Data from EPA Sampling Episode at Albany ............................... 177

13.4.3 COD Self-Monitoring Data from Albany Airport .................................. 178
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

CONTENTS (Continued) 

Page 

vi 

13.5 Ammonia: Data Selected as Basis of Final Limitation ....................................... 181

13.6 Limitations: Basis and Calculations.................................................................... 182

13.6.1 Definitions............................................................................................... 183

13.6.2 Percentile Basis of the Limitations ......................................................... 183

13.6.3 Estimation Procedures for Percentiles .................................................... 184

13.7 Achievability of Limitations ............................................................................... 187

13.7.1 Statistical and Engineering Review of Limitations ................................ 188

13.7.2 Compliance with Limitations .................................................................. 190

13.8 References ........................................................................................................... 192
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

vii 

LIST OF TABLES 

Page 

3-1 Airports Visited ....................................................................................................................8

3-2 Deicing Questionnaire Response Rates .............................................................................10

3-3 Airports Selected for Sampling and the Reason for Their Selection .................................15

3-4 Top 50 Airports in the United States with the Highest ADF Usage, Estimated 

Based on SOFP Days and Total Airport Departures .........................................................17

3-5 Permit Review General Information Table ........................................................................19

3-6 Permit Review Pollutant-Specific Information Table ........................................................20

3-7 Summary of Costing Data Provided by Industry ...............................................................21

3-8 Summary of Long-Term Analytical Data Provided by Industry .......................................21

3-9 Selected Airport Information Related to Deicing Pad Operations .....................................25

4-1 Number of U.S. Airports by Airport Type in 2004 ............................................................29

4-2 Deicing Airports by FAA Region for the Three Winter Seasons ......................................30

4-3 Airline Classifications ........................................................................................................33

4-4 National Estimate of Airports Using Deicing Chemicals or Materials ..............................35

4-5 Deicing/Anti-Icing Chemicals Purchased by Airlines that Deiced Their Own 

Aircraft ...............................................................................................................................37

4-6 Deicing/Anti-Icing Chemicals Purchased for Aircraft Deiced by an FBO ........................37

4-7 Summary of Mechanical and Nonchemical Aircraft Deicing Methods Used by an 

Airline ................................................................................................................................38

4-8 Summary of Mechanical and Nonchemical Aircraft Deicing Methods Used By 

FBOs ..................................................................................................................................38

4-9 Summary of Airport Collection, Containment, and Conveyance Methods .......................39

4-10 Summary of Airfield Pollution Prevention Practices .........................................................40

4-11 Summary of Aircraft Pollution Prevention Practices .........................................................40

5-1 U.S. Commercial Airports – National Estimate of Airfield Chemical Usage ...................42
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

LIST OF TABLES (Continued) 

Page 

viii 

5-2 U.S. Commercial Airports – National Estimate of Aircraft Chemical Usage 1 .................43

5-3 EPA’s Analytical Results for Pond 3E Effluent and Pond 6 Effluent, DTW ....................45

5-4 MSP and DTW Grab Sample Data Summary for Collected Deicing Stormwater ............47

5-5 DEN, PIT, and ALB - 5-Day Average Data Summary for Untreated Deicing 

Stormwater .........................................................................................................................49

5-6 RFD - 1-Day Data Summary for Untreated Deicing Stormwater ......................................52

6-1 Pollutants Under Consideration as Potential Pollutants of Concern ..................................57

6-2 Potential Pollutants of Concern Selected for Regulation ...................................................65

7-1 ADF Alternatives ...............................................................................................................82

9-1 ADF Estimates Based on Airline Detailed Questionnaire Responses ...............................93

9-2 ADF Data Reported in the Airport Questionnaire .............................................................95

9-3 ADF Annual Usage Estimates for In-scope Airports ........................................................97

9-4 Theoretical Oxygen Demand Calculations for Aircraft Deicing Chemicals ...................100

9-5 ADF COD Baseline Loads and Loading Reductions for Each Control and 

Treatment Scenario, by In-Scope Airport ........................................................................103

9-6 Three-Year Average Amount of Pavement Deicing Chemical Usage, in Pounds ..........108

9-7 ThOD Calculations for Airfield Deicing Chemicals .......................................................112

9-8 Baseline Ammonia and COD Load and Potential Load Reduction Associated with 

the Discontinued Use of Urea as an Airfield Deicing Chemical for In-Scope 

Airports ............................................................................................................................114

10-1 GCV Capital and O&M Costs .........................................................................................121

10-2 Normalized Capital and O&M Costs for the Plug and Pump Collection System ...........122

10-3 Estimated Cost for 10,000 Linear Feet of Stormwater Piping .........................................124

10-4 Storage Tank Volumes and Installed Capital Cost for Various Airports .........................125

10-5 Normalized Annual O&M Costs for the AFB Reactors ..................................................127
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

LIST OF TABLES (Continued) 

Page 

ix 

10-6 Airport Deicing Cost Model Equations, Input Variables, and Assumptions ...................131

10-7 Annualized Costs by Model Facility for Control and Treatment ....................................134

10-8 Average Cost for Urea and Potassium Acetate, 2002-2005 ............................................138

10-9 Typical Application Rates for Potassium Acetate ...........................................................138

10-10 Application Rates for Sodium Acetate and Urea .............................................................138

10-11 Cost for Application of Urea and Potassium Acetate, per 1000 Square Feet ..................139

10-12 Application Equipment Costs for Liquid Pavement Deicer ............................................140

10-13 Storage Tank Capital Costs for Liquid Pavement Deicer ................................................141

10-14 Annualized Costs for In-Scope Airports to Change from Urea to Potassium 

Acetate for Airfield Deicing ............................................................................................142

10-15 Other Compliance-Related Costs by Airport ...................................................................144

10-16 Summary of EPA’s Annualized Costs for ADF Collection and Treatment, Airfield 

Deicing Urea Substitution, and Other Compliance-Related Costs ..................................149

11-1 Final Rule BAT Annualized Costs and Load Removals for In-Scope Airports ..............156

12-1 Potential Electricity Generation from AFB Biogas Generation ......................................166

12-2 Estimated Incremental Pollutant Emissions from GCVs .................................................167

12-3 Potential Air Emissions from AFB Treatment Systems ..................................................168

12-4 Estimated Sludge Generation from AFB Bioreactors Treating ADF-Contaminated 

Stormwater .......................................................................................................................169

13-1 COD: EPA and Albany Airport Self-Monitoring Effluent Data Collected During 

EPA’s Sampling Episode .................................................................................................178

13-2 COD: Dates Excluded Because Units Operated in Series ...............................................179

13-3 COD: Dates Excluded Because Influent Concentration Reported as Zero ......................179

13-4 COD: Dates Excluded Because of Performance Excursions ...........................................180

13-5 COD: Summary of Albany Airport Self-Monitoring Effluent Data After 

Exclusions ........................................................................................................................181
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

LIST OF TABLES (Continued) 

Page 

x 

13-6 Ammonia: Data from Albany Airport Used to Develop Limitations ..............................182

13-7 COD and Ammonia: Final Limitations with Long-Term Averages and Variability 

Factors .............................................................................................................................185

13-8 COD: 99th Percentile Estimates from Each Treatment Unit ............................................185

13-9 COD: Effect of Number of Daily Values in Weekly Averages .......................................186

13-10 Ammonia: Consideration of Autocorrelation for Final Limitations, Long-Term 

Averages, and Variability Factors ....................................................................................187

13-11 COD: Dates and Values Greater than Final Limitation of 271 mg/L ..............................189

13-12 COD: Summary Statistics of Influent Concentrations .....................................................190
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

xi 

LIST OF FIGURES 

Page 

4-1 Percentage of Airports Deicing Airfield Pavement Each Month .......................................31

4-2 Discharge Status of Airports ..............................................................................................32

7-1 Deicing Pad Equipped with Fixed Deicing Booms at Pittsburgh Airport .........................69

7-2 GCV ..................................................................................................................................71

7-3 Pond for Deicing Stormwater Storage ...............................................................................73

7-4 Frac Tanks ..........................................................................................................................74

7-5 Aerated Pond Installation at Portland Airport ...................................................................76

7-6 Typical Anaerobic Fluid Bed Treatment System for Treatment of ADFContaminated Stormwater .................................................................................................77

7-7 Infrared Hangar at JFK ......................................................................................................81

9-1 ADF Factor vs. PG/EG Gallons for U.S. Airports (excluding Alaska) .............................95

9-2 ADF Factor vs. PG/EG Gallons for Alaskan Airports .......................................................96

10-1 AFB Reactor Capital Cost for Treating ADF-Contaminated Stormwater .......................126

13-1 Simplified Drawing of Albany Airport Treatment System and Sample Points ...............177
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 1 – Legal Authority 

1 

1. LEGAL AUTHORITY

Effluent limitation guidelines and standards for the Airport Deicing Category are 

promulgated under the authority of sections 301, 304, 306, 307, 308, and 501 of the Clean Water 

Act, 33 U.S.C. 1311, 1314, 1316, 1317, 1318, and 1361. 

1.1 Clean Water Act 

Congress passed the Federal Water Pollution Control Act Amendments of 1972, also 

known as the Clean Water Act (CWA), to “restore and maintain the chemical, physical, and 

biological integrity of the Nation’s waters” (section 101(a)). To implement the Act, the United 

States Environmental Protection Agency (EPA) is to issue effluent limitation guidelines, 

pretreatment standards, and new source performance standards for industrial dischargers. These 

guidelines and standards are summarized briefly in the following sections. 

1.1.1 Best Practicable Control Technology Currently Available (BPT) 

Traditionally, EPA establishes BPT effluent limitations based on the average of the best 

performances of facilities within the industry, grouped to reflect various ages, sizes, processes, or 

other common characteristics. EPA may promulgate BPT effluent limits for conventional, toxic, 

and nonconventional pollutants. In specifying BPT, EPA looks at a number of factors. EPA first 

considers the cost of achieving effluent reductions in relation to the effluent reduction benefits. 

The Agency also considers the age of the equipment and facilities, the processes employed, 

engineering aspects of the control technologies, and required process changes, non-water-quality 

environmental impacts (including energy requirements), and such other factors as the 

Administrator deems appropriate. See CWA section 304(b)(1)(B)). If, however, existing 

performance is uniformly inadequate, EPA may establish limitations based on higher levels of 

control than are currently in place in an industrial category when based on an Agency 

determination that the technology is available in another category or subcategory, and can be 

practically applied. 

1.1.2 Best Conventional Pollutant Control Technology (BCT) 

The 1977 amendments to the CWA required EPA to identify additional levels of effluent 

reduction for conventional pollutants associated with BCT technology for discharges from 

existing industrial point sources. In addition to other factors specified in section 304(b)(4)(B), 

the CWA requires that EPA establish BCT limitations after consideration of a two-part “costreasonableness” test. EPA explained its methodology for the development of BCT limitations in 

July 1986 (51 FR 24974). Section 304(a)(4) designates the following as conventional pollutants: 

biochemical oxygen demand over 5 days (BOD5), total suspended solids (TSS), fecal coliform, 

pH, and any additional pollutants defined by the Administrator as conventional. The 

Administrator designated oil and grease as an additional conventional pollutant on July 30, 1979 

(44 FR 44501; 40 CFR 401.16). 

1.1.3 Best Available Technology Economically Achievable (BAT) 

BAT represents the second level of stringency for controlling direct discharge of toxic 

and nonconventional pollutants. In general, BAT effluent limitation guidelines represent the best 

economically achievable performance of facilities in the industrial subcategory or category. The 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 1 – Legal Authority 

2 

factors considered in assessing BAT include the cost of achieving BAT effluent reductions, the 

age of equipment and facilities involved, the process employed, potential process changes, and 

non-water quality environmental impacts including energy requirements, and such other factors 

as the Administrator deems appropriate. The Agency retains considerable discretion in assigning 

the weight to be accorded these factors. An additional statutory factor considered in setting BAT 

is economic achievability. Generally, EPA determines economic achievability based on total 

costs to the industry and the effect of compliance with BAT limitations on overall industry and 

subcategory financial conditions. As with BPT, where existing performance is uniformly 

inadequate, BAT may reflect a higher level of performance than is currently being achieved 

based on technology transferred from a different subcategory or category. BAT may be based 

upon process changes or internal controls, even when these technologies are not common 

industry practice. 

1.1.4 New Source Performance Standards (NSPS) 

NSPS reflect effluent reductions that are achievable based on the best available 

demonstrated control technology. New facilities have the opportunity to install the best and most 

efficient production processes and wastewater treatment technologies. As a result, NSPS should 

represent the most stringent controls attainable through the application of the best available 

demonstrated control technology for all pollutants (i.e., conventional, nonconventional, and 

priority pollutants). In establishing NSPS, EPA is directed to take into consideration the cost of 

achieving the effluent reduction and any non-water quality environmental impacts and energy 

requirements. 

1.1.5 Pretreatment Standards for Existing Sources (PSES) 

Pretreatment standards apply to discharges of pollutants to publicly owned treatment 

works (POTWs) rather than to discharges to waters of the United States. PSES are designed to 

prevent the discharge of pollutants that pass through, interfere with, or are otherwise 

incompatible with the operation of POTWs. Categorical pretreatment standards are technologybased and analogous to BAT effluent limitation guidelines. The General Pretreatment 

Regulations, which set forth the framework for the implementation of categorical pretreatment 

standards, are found at 40 CFR Part 403. These regulations establish pretreatment standards that 

apply to all nondomestic dischargers. See 52 FR 1586 (January 14, 1987). 

1.1.6 Pretreatment Standards for New Sources (PSNS) 

Section 307(c) of the Act calls for EPA to promulgate PSNS at the same time it 

promulgates NSPS. Such pretreatment standards must prevent the discharge of any pollutant into 

a POTW that may interfere with, pass through, or may otherwise be incompatible with the 

POTW. EPA promulgates categorical PSES based principally on BAT technology for existing 

sources. EPA promulgates PSNS based on best available demonstrated technology for new 

sources. New indirect discharges have the opportunity to incorporate into their facilities the best 

available demonstrated technologies. The Agency considers the same factors in promulgating 

PSNS as it considers in promulgating NSPS. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 1 – Legal Authority 

3 

1.2 Effluent Guidelines Plan

In 2004, EPA issued its biannual effluent guidelines plan under section 304(m) of the 

CWA. This plan announced the initiation of rulemaking for the Airport Deicing Category (69 FR 

53705, September 2, 2004). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 2 – Applicability and Subcategorization 

4 

2. APPLICABILITY AND SUBCATEGORIZATION

This document presents the information and rationale supporting the effluent limitation 

guidelines and standards for the Airport Deicing Category. Section 2 highlights the applicability 

and subcategorization basis of this regulation. 

2.1 Applicability of the Regulation

Airports in the scope of this regulation are defined as Primary Commercial Airports that 

conduct deicing activities. 

2.2 Subcategorization

The CWA requires EPA to consider a number of different factors when developing 

effluent limitation guidelines. For example, when developing limitations that represent the BAT 

for a particular industrial category, EPA must consider among other factors the following: the 

age of the equipment and facilities in the category, location, manufacturing processes employed, 

types of treatment technology to reduce the effluent discharges, costs of effluent reductions, and 

non-water-quality impacts (CWA section 304(b)(2)(B)). The statute also allows EPA to take into 

account other factors that the EPA Administrator deems appropriate and requires the BAT model 

technology chosen by EPA to be economically achievable, which generally involves considering 

both compliance costs and overall financial condition of the industry. 

For this rulemaking, EPA evaluated the characteristics of the Airport Deicing Category to 

determine their potential to provide the Agency with a means to differentiate effluent quantity 

and quality among facilities. EPA also evaluated the design, process, and operational 

characteristics of the different industry segments to determine technology control options that 

might be applied to reduce effluent quantity and improve effluent quality. Based on this analysis, 

below are the factors that EPA evaluated to determine whether subcategorizing the Airport 

Decicing Category would be appropriate: 

• Aircraft deicing fluid (ADF) usage; 

• Federal Aviation Administration (FAA) classifications; and 

• Land availability. 

2.2.1 ADF Usage 

Ethylene glycols (EG) and propylene glycols (PG) are the main ingredients in ADF. 

Through EPA’s research, it became apparent that the volume of glycol required to deice a single 

aircraft varied greatly depending on a number of variables including weather conditions, aircraft 

size, and operator training. EPA reviewed industry questionnaire responses and determined that 

ADF usage is the best indicator for the volume of deicing operations that occur at an airport. 

ADF usage can range from zero to hundreds of thousands of gallons per year at airports across 

the United States. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 2 – Applicability and Subcategorization 

5 

2.2.2 FAA Classification 

The Airport and Airway Improvement Act (AAIA) and the FAA classify airports by size 

based on the volume of commercial traffic. (Noncommercial airports, commonly known as 

"General Aviation" airports, are not specifically defined by the AAIA.) EPA utilized this 

classification system to organize its data collection and analysis of the aviation industry. The 

AAIA defines airports by categories of airport activities, including Commercial Service (Primary 

and Nonprimary), Cargo Service, and Reliever. Commercial Service Airports are publicly owned 

airports that have at least 2,500 passenger boardings each calendar year and receive scheduled 

passenger service. The definition also includes passengers who continue on an aircraft in 

international flight that stops at an airport in any of the 50 states for a nontraffic purpose, such as 

refueling or aircraft maintenance rather than passenger activity. Primary Commercial Service 

airports have more than 10,000 passenger boardings each year. Primary Commercial Service 

airports are further subdivided into Large Hub, Medium Hub, Small Hub, and Non-hub 

classifications, based on the percentage of total passenger boardings within the United States in 

the most current calendar year ending before the start of the current fiscal year. 

Early in the regulatory process, EPA assumed that the majority of the deicing in the 

United States would occur at Primary Commercial Service airports and particularly those with 

nonpropeller departures. General aviation aircraft, as well as smaller commercial propeller 

driven aircraft are expected to suspend flights during inclement weather, whereas commercial 

aircraft with scheduled service are much more likely to deice to meet customer demands. 

2.2.3 Land Availability 

EPA is aware that airports across the country have different amounts of land that may be 

available for facility modifications, such as installing environmental controls. EPA collected 

some basic information from airports on their current configurations. However, neither the 

aviation industry nor the FAA has developed a standard definition of land availability. 

As part of the public comments on the proposed rule, commenters requested that EPA 

subcategorize airports that would be prohibited from installing deicing pads due to gate, runway, 

and taxiway space constraints and lack of available land. EPA did not set a spent ADF collection 

requirement as part of BAT in the final rule and therefore did not separate these airports into 

their own subcategory. 

2.2.4 Conclusions 

EPA concludes that establishing formal subcategories is not necessary for the Airport 

Deicing Category; rather, EPA structured the applicability of the final rule to address the relevant 

factors and established a set of requirements that encompasses the range of situations that an 

airport may encounter during deicing operations. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

6 

3. DATA COLLECTION ACTIVITIES

To characterize airport deicing operations and to develop the final effluent limitation 

guidelines and standards, EPA collected and evaluated technical and economic data from a 

variety of sources. This section describes the following data sources used for the Airport Deicing 

Category rulemaking effort: 

Section 3.1 – Preliminary Data Summary 

Section 3.2 – Site Visits 

Section 3.3 – Industry Questionnaires (Surveys) 

Section 3.4 – Field Sampling 

Section 3.5 – Permit Review 

 Section 3.6 – Deicing Pad Costs 

Section 3.7 – Industry-Supplied Data 

Section 3.8 – Literature Reviews 

 Section 3.9 – Data Collected as Part of Public Comments 

3.1 Preliminary Data Summary

EPA’s initial source of wastewater discharge information for the aviation industry was 

the Preliminary Data Summary (PDS): Airport Deicing Operations, which was published in 

August 2000 (USEPA, 2000). This study focused on approximately 200 U.S. airports with 

potentially significant deicing/anti-icing operations. For the study, EPA collected information 

from industry questionnaires, engineering site visits, wastewater sampling activities, meetings 

with industry and regulatory agencies, and technical and scientific literature. See Section 3.0 of 

the PDS for detailed information on the study’s data collection activities. 

The questionnaires that EPA reviewed included the 1993 Screener Questionnaire for the 

Transportation Equipment Cleaning Industry and a set of questionnaires distributed during the 

study to major and regional airports and airlines, technology vendors, and POTWs. 

From September 1997 through March 1999, the Agency conducted 16 airport site visits 

and six sampling episodes to collect information about deicing processes, deicing equipment, and 

deicing wastewater generation, collection, handling, and treatment technologies. 

EPA met with the FAA, deicing fluid manufacturers and formulators, airlines, industry 

associations, technology vendors, and other interested parties to discuss environmental and 

operational issues related to aircraft deicing and anti-icing operations. 

Literature searches provided information on the toxicity, industry usage, and mitigation 

techniques for ADFs. The literature also covered topics such as alternative fluid types, pollution 

prevention practices, economic and financial data, and environmental impacts. 

3.2 Site Visits

Between December 2004 and November 2005, EPA conducted 20 airport site visits to 

collect current information about aircraft and airfield deicing practices, deicing equipment, 

deicing stormwater generation, collection, handling, and control. During these site visits, EPA 

also evaluated potential sampling locations for the sampling program described in Section 3.4. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

7 

EPA used information collected from the PDS, updated airport literature searches, and 

other Agency-supplied data to assess potential airports for site visits. EPA also solicited 

recommendations from industry trade associations, including the Air Transport Association 

(ATA), the American Association of Airline Executives (AAAE) and Airports Council 

International-North America (ACI-NA). EPA considered the following criteria in evaluating 

which airports to visit: 

• Hub size and location of the airport; 

• ADF handling practices; 

• Deicing stormwater collection and control practices; and 

• ADF-contaminated stormwater discharge practices. 

In general, EPA visited Medium Hub and Large Hub airports operating in northern 

climates that conduct aircraft and airfield deicing operations each winter. EPA also visited some 

Small Hub airports to evaluate potential issues related to an airport’s size. The Agency visited 

airports that use a variety of deicing practices (such as gate deicing, centralized deicing pads 

(CDPs), deicing trucks and stationary booms, infrared deicing hangars) and various deicing 

stormwater collection and control technologies (such as dedicated deicing stormwater collection 

systems, stormwater treatment through biological systems, and glycol recovery systems). Table 

3-1 lists the 20 airports visited in 2004 and 2005, the visit dates, and EPA’s rationale for 

selecting each for a site visit. This table also lists a post-proposal site visit conducted at Boston 

Logan airport. 

During the site visits, EPA collected the following information: 

• General airport and deicing operations information, including size and age of the 

airport, permit status, information on the entities that perform deicing operations 

(both aircraft and airfield), and current airline tenant information; 

• Description of the deicing/anti-icing operations conducted at the airport, including 

the types of equipment used, locations of deicing operations, and information on 

any pollution prevention or “state-of-the-art” systems in use at the airport that 

improved their deicing operations; 

• Deicing chemicals used, including ADF type (e.g., Type I-IV), pavement deicer 

type, and any chemical usage information available; 

• Description of the deicing stormwater collection and control systems used at the 

airport, including any glycol recovery or stormwater treatment systems and their 

effectiveness and any available cost information for these systems; and 

• Airport monitoring and discharge of deicing stormwater, including pollutants 

monitored and frequency of monitoring. 

This information is documented in the Site Visit Report (SVR) for each airport visited. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

8 

Table 3-1. Airports Visited 

Airport Name 

Airport 

Code Date of Visit Airport Details 

Washington Dulles 

International 

IAD 12/1/2004 Local Large Hub airport, ADF-contaminated 

stormwater collection and glycol recovery, indirect 

discharger 

Baltimore-Washington 

International 

BWI 12/15/2004 Local Large Hub airport, deicing pads, ADFcontaminated stormwater collection, indirect 

discharger 

Chicago O’Hare 

International 

ORD 1/26/2005 Large Hub airport, ADF-contaminated stormwater 

collection with indirect discharge, upgrades to system 

since the PDS site visit 

General Mitchell 

International 

(Milwaukee) 

MKE 1/27/2005 Medium Hub airport, ADF-contaminated stormwater 

collection and indirect discharge, extensive monitoring 

data in collaboration with U.S. Geological Survey 

(USGS) 

Detroit Metropolitan 

Wayne County 

DTW 1/28/2005 Large Hub airport, deicing pads, ADF-contaminated 

stormwater collection with glycol recovery, both direct 

and indirect discharger 

Ronald Reagan 

Washington National 

DCA 2/1/2005 Local Large Hub airport, changes in ADF practices 

since PDS site visit, ADF-contaminated stormwater 

collection 

Syracuse Hancock 

International 

SYR 2/9/2005 Small Hub airport, deicing pads, aerated stormwater 

lagoons, indirect discharger 

Albany International ALB 2/10/2005 Small Hub airport, ADF-contaminated stormwater 

collection with anaerobic and aerobic treatment, direct 

discharger, upgrades to system since PDS site visit 

Pittsburgh International PIT 2/10/2005 Large Hub airport, deicing pads, glycol recovery and 

treatment (ultra filtration and reverse osmosis) of ADFcontaminated stormwater, direct discharger 

Cincinnati/Northern 

Kentucky International 

CVG 2/11/2005 Large Hub airport, variety of ADF-contaminated 

stormwater-related activities, recommended by FAA as 

a site visit location, on-site aerobic treatment, direct 

and indirect discharger 

Richmond International RIC 2/16/2005 Local Small Hub airport 

Minneapolis/St. Paul 

International/WorldChamberlain 

MSP 2/18/2005 Large Hub airport, ADF collection with glycol 

recovery, direct and indirect discharger 

James M Cox Dayton 

International 

DAY 2/25/2006 Small Hub airport, centralized deicing with ADFcontaminated stormwater collection 

Portland International 

(Oregon) 

PDX 7/26/2005 Medium Hub northwestern airport, indirectly 

discharges high-strength deicing stormwater, sends 

low-strength deicing stormwater to detention pond and 

then to direct discharge 

Seattle-Tacoma 

International 

SEA 7/27/2006 Large Hub northwestern airport, industrial stormwater 

treatment on site 

LaGuardia (New York) LGA 10/11/2005 Large Hub airport, direct discharger, part of New York 

City area visits 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

Table 3-1 (Continued) 

9 

Airport Name 

Airport 

Code Date of Visit Airport Details 

John F. Kennedy 

International (New 

York) 

JFK 10/11/2005 Large Hub airport with a high percentage of 

international flights, direct discharger, part of New 

York City area visits, future plans for infrared deicing 

Newark Liberty 

International 

EWR 10/12/2005 Large Hub airport, infrared deicing technology since 

1999 

Salt Lake City 

International 

SLC 11/8/2005 Large Hub western airport, ADF-contaminated 

stormwater collection with glycol recovery 

Denver International DEN 11/9/2005 Large Hub western airport, deicing pads, ADFcontaminated stormwater collection with glycol 

recovery 

General Edward 

Lawrence Logan 

International 

BOS 3/21/2011 Space-constrained airport with no ADF-contaminated 

stormwater collection and direct discharge 

3.3 Industry Questionnaires (Surveys)

EPA distributed three questionnaires to directly support the Airport Deicing rulemaking. 

Section 3.3.1 discusses the recipient selection process, distribution, and mail-out results for the 

three airport deicing questionnaires. Section 3.3.2 discusses the organization of and type of 

technical information requested in each questionnaire. 

3.3.1 Recipient Selection and Questionnaire Distribution 

EPA distributed a screener questionnaire followed by a detailed airline questionnaire to 

airlines, and a questionnaire to airports. The overall focus of the questionnaires was on airports 

and airlines that perform deicing and anti-icing on aircraft and/or airfield pavement. EPA 

selected airports for the airport questionnaire by airport type (i.e., Large Hub, Medium Hub, 

Small Hub, and Non-hub), days and amount of snow or freezing precipitation, and the number of 

departures. EPA performed a census design for large and Medium Hub1

 airports and a stratified 

random sample design for small and Non-hub airports (see the Statistical Support Memorandum

DCN AD01208). 

EPA selected recipients for the airline screener questionnaire by identifying airlines with 

greater than 1,000 departures per year at those airports selected for the airport questionnaire. 

EPA selected airlines for the detailed airline questionnaire based on the airline screener 

questionnaire responses (which identified whether an airline deiced its aircraft or used some 

other entity) at the specified airports. To reduce respondent burden, EPA asked the selected 

 

1

FAA classifies large commercial airports into size categories of “hubs,” based on the number of annual 

enplanements that occur at the airport. Enplanements represent the number of passengers boarding the plane for 

departure. Large Hubs are airports that represent more than 1 percent of total U.S. passenger enplanements. Medium 

Hubs are airports that account for more than 0.25 percent but less than 1 percent of total passenger enplanements. 

Small Hubs enplane 0.05 to 0.25 percent of the total passenger enplanements. Airports with less than 0.05 percent of 

the total passenger enplanements but more than 10,000 annual enplanements are considered Non-hub primary 

airports. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

10 

airlines to provide data on a limited subset of the airports they served for which they were 

expected to use the maximum amount of deicing chemicals. 

Table 3-2 summarizes the number of questionnaires distributed in each category and their 

response rates. 

Table 3-2. Deicing Questionnaire Response Rates 

Questionnaire Type Distributed 

Returned 

Undelivered 

Returned 

Completed Not Returned 

Airport Deicing Questionnaire 153 0 (0%) 150 (98%) 3 (2%) 1

Airline Screener Questionnaire2 72 1 (1%) 70 (97%) 1 (1%) 

Airline Deicing Detailed Questionnaire 58 0 (0%) 49 (84%) 9 (16%) 

1 EPA determined that one airport recipient was out of scope and removed it from the sample frame. 

2 Information was collected from an additional 22 foreign carriers. 

3.3.1.1 Airport Questionnaire 

EPA selected 153 airports to receive the airport questionnaire and distributed the 

questionnaire to these airports in April 2006. Of the 153 airport questionnaires distributed, 150 

were completed and returned. EPA removed one of the three nonrespondent airports from the 

sample frame because it was a city airport operating as a tenant at a military airport. EPA 

determined that its selection was based on data for the military airport operations, not the city 

airport, and military airports were not included in the sample frame. 

3.3.1.2 Airline Screener Questionnaire 

EPA initially selected 72 airlines as recipients of the screener questionnaire. The recipient 

group comprised a random sample of airlines with greater than 1,000 departures per year 

operating at the airports selected for the airport questionnaire. In April 2006, the Agency 

distributed the airline screener questionnaire to the 72 airlines. EPA also identified 22 additional 

foreign airlines for which information would be useful in developing effluent guidelines, but that 

were not captured by the random sample. EPA collected aircraft deicing and anti-icing 

information for these 22 foreign carriers through contacts with airport managers where the 

carriers operated. 

Of the 72 screener questionnaires distributed, 70 were completed and returned to EPA. 

Of the two not returned, one questionnaire was returned undelivered, as the airline had ceased 

operations. 

3.3.1.3 Airline Detailed Questionnaire 

Using the responses from the airline screener questionnaire, EPA selected and sent a 

more detailed questionnaire to 58 airlines that responded they deice planes at any of the airports 

that received an airport questionnaire. This questionnaire was distributed in March 2007. The 

selection included 448 airline/airport combinations. The Agency categorized the airline/airport 

combinations according to the entity that performed most of the deicing for the 2002/2003, 

2003/2004, and 2004/2005 winter seasons as listed below: 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

11 

• Airline/airport combinations that deice their own aircraft; 

• Airline/airport combinations that contract to fixed-base operators (FBOs) for 

deicing services; or 

• Airline/airport combinations that contract to other airlines for deicing services. 

Of the 58 airline detailed questionnaires sent, 49 were completed returned and nine were 

not returned. 

3.3.2 Questionnaire Information Collected 

EPA designed the questionnaires to collect current information with sufficient detail to 

support development of effluent guidelines. The questionnaires collected information on deicing 

operations performed on aircraft and airfield pavement, including deicing stormwater generation, 

collection, characterization, management, and treatment. The airline screener supported the 

selection of recipients for the airline detailed questionnaire. This section describes the technical 

information collected and the purpose of each of the three questionnaires. 

3.3.2.1 Airport Questionnaire 

EPA divided the airport deicing questionnaire into the following parts and sections: 

PART A: TECHNICAL INFORMATION 

Section 1: General Airport Information 

Section 2: Airport Deicing and Anti-Icing Operations 

Section 3: Deicing Stormwater Containment and/or Collection 

Section 4: Deicing Stormwater Treatment/Recovery 

Section 5: Analytical Data 

Section 6: Pollution Prevention Practices 

PART B: FINANCIAL AND ECONOMIC INFORMATION 

Section 1: Ownership and Management Structure 

Section 2: Airport Finances 

Section 3: Capital Expenditures 

Section 4: Airport Operations 

Part A, Section 1 (Questions 1 through 24) requested information to identify the airport 

and primary contacts, to confirm that aircraft deicing/anti-icing was performed during the three 

designated winter seasons (2002/2003, 2003/2004, and 2004/2005), and to characterize deicing 

operations. This information included the destination of deicing/anti-icing stormwater, receiving 

surface waters, the entity that performed aircraft and/or airfield pavement deicing, and the 

number of deicing/anti-icing days per winter season. This information helped EPA update the 

industry profile on airports deicing in the U.S., characterize deicing/anti-icing operations, and 

determine the proximity and types of ecosystems within and beyond airport boundaries 

Part A, Section 2 (Questions 25 through 31) requested detailed information about airport 

deicing/anti-icing stormwater sources, flows, and destinations as well as deicing/anti-
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

12 

icingchemicals, materials, and practices. EPA used this information to develop an industry 

profile of deicing stormwater generation and collection, to determine baseline loadings using 

airfield deicing chemical usage, and to develop and evaluate possible regulatory technology 

options and compliance cost estimates. 

Part A, Section 3 (Questions 32 through 39) requested information on the collection, 

containment, conveyance, discharge and/or disposal methods for deicing stormwater, and 

pollution prevention and best management practices. EPA used this information to develop an 

industry profile of deicing stormwater collection/containment/conveyance methods and to 

evaluate pollution prevention and best management practices. 

Part A, Section 4 (Questions 40 through 51) requested information on deicing stormwater 

treatment technologies and units operated by the airport, including deicing stormwater treatment 

diagrams, design and operating specifications, sources of wastewater influent, treatment 

chemical additions, treatment operations and maintenance costs, and discharge practices. EPA 

used this information to develop control technology options, regulatory options, and compliance 

cost estimates. 

Part A, Section 5 (Questions 52 through 55) requested information concerning the 

availability of deicing stormwater characterization data, receiving water in-stream monitoring 

data, and/or data characterizing the effectiveness of treatment of deicing stormwater. EPA used 

this information to follow up with selected airports to request long-term monitoring data, to 

estimate pollutant discharge loadings, to characterize behavior of the discharge in the receiving 

water, to assess deicing stormwater treatment technologies, and to assess environmental impacts. 

Part A, Section 6 (Questions 56 through 68) requested information to evaluate the status 

of pollution prevention practices at each airport and to identify pollution prevention 

technologies. EPA used this information to identify appropriate practices as regulatory options 

and to prepare an industry profile of pollution prevention practices. 

Part B of the questionnaire requested airport financial and economic information. 

Section 1 requested information on the ownership and management structure that EPA used to 

develop the industry profile and to estimate economic impacts of an effluent guideline. Section 2 

requested information on operation finances that EPA used to project the potential impacts of the 

rule. Section 3 requested information on current capital airport expenditures that EPA used to 

assess the capability of airports to pay for deicing-related capital improvements. Section 4 

requested information on the finances for airport operations, including the airport’s financial 

statement, which EPA used to determine the airport’s cost of capital. 

3.3.2.2 Airline Screener Questionnaire 

The airline screener questionnaire included three questions. Question 1 requested the 

contact information for the airline should EPA need to verify or clarify their response. Question 

2 asked who (the airline, another airline, FBO, or private contractor) performed most of the 

deicing/anti-icing on the respondent’s aircraft at specific airports. Question 3 provided an 

opportunity for the respondent to provide additional information or comment on its responses. 

EPA used this information to identify potential airline detailed questionnaire recipients and to 

indicate the potential contribution of FBOs to deicing operations and to the discharge of ADFcontaminated stormwater. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

13 

3.3.2.3 Airline Detailed Questionnaire 

EPA divided the airline detailed questionnaire into the following parts and sections: 

PART A: TECHNICAL INFORMATION 

Section 1: General Airline Information 

Section 2: Airline Deicing and Anti-Icing Operations (at each airport specified in 

Section 1) 

Section 3: Pollution Prevention Practices (at each airport specified in Section 1) 

PART B: DEICING COSTS AND OPERATIONS 

Section 1: Airline Deicing Costs and Operations 

Section 2: Airport-Specific Deicing Costs and Operations 

Part A, Section 1 (Questions 1 through 4) requested verification of the airline name and 

address and identification of the primary and secondary contacts to clarify or verify the technical 

questionnaire responses. 

Part A, Section 2 (Questions 5 through 18) requested information on deicing/anti-icing 

operations performed by the airline or for the airline at each specified airport. The Agency used 

this information to: 

• Develop an industry profile of ADF usage and deicing stormwater generation; 

• Estimate pollutant loadings; 

• Characterize deicing stormwater; 

• Evaluate differences in airport deicing stormwater generation and characteristics; 

• Identify pollutants of concern; and 

• Identify opportunities for pollution prevention through chemical substitution and 

best management practices. 

Part A, Section 3 (Questions 19 through 31) requested information on the airline’s 

pollution prevention practices including a description of each practice and any costs and/or 

savings from its implementation. The Agency evaluated this information to identify appropriate 

practices that could become part of regulatory options and to develop an industry profile. 

Part B of the questionnaire requested airline financial and economic information. 

Section 1 requested information on ownership, aircraft deicing costs and operations, and the 

airline’s financial statement, that EPA used to develop the industry economic profile and to 

conduct the economic analysis. Section 2 requested detailed information regarding airlinespecific deicing costs and operations at specific airport locations. The Agency also used this 

information for the industry economic profile and to determine the economic impacts of the rule. 

3.3.3 Questionnaire Review, Coding, and Data Entry 

EPA reviewed the screener and the two detailed questionnaires for completeness, 

accuracy, and consistency of the responses. In some cases, the Agency followed up with the 

airport or airline by email or telephone to clarify responses or to obtain missing or incomplete 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

14 

information. During the review, EPA coded responses to facilitate entry of data into the airline 

screener and the airline and airport questionnaire databases. 

The Agency developed databases containing the information provided by questionnaire 

respondents of each questionnaire. After detailed review and coding, EPA entered data from the 

questionnaires into the appropriate database using a double-key-entry and verification procedure 

to identify and resolve differences between the two data entry tasks. 

3.4 Field Sampling

EPA conducted sampling episodes at six airports from March 2005 through August 2006 

to characterize ADF and ADF-contaminated stormwater discharges and to evaluate treatment 

technologies for stormwater affected by aircraft and airfield deicing practices. EPA used existing 

industry profile information and information collected during airport site visits to determine the 

most appropriate locations for sampling. The Agency evaluated the following criteria for 

selecting sampling sites: 

• Size and location of the airport; 

• Deicing stormwater collection and control practices; and 

• ADF-contaminated stormwater discharge practices. 

EPA conducted the episodes to characterize deicing stormwater and assess the 

capabilities and effectiveness of several different treatment technologies such as anaerobic 

treatment, aerobic treatment, distillation, reverse osmosis, mechanical vapor recompression, 

aeration, and chemical addition. Table 3-3 lists the airports selected for EPA sampling, the 

reason for selection, and the points that were sampled. 

3.5 Permit Review

During the regulatory development process, EPA reviewed National Pollutant Discharge 

Elimination System (NPDES) permits to understand what permit authorities are currently 

requiring of airports with respect to deicing stormwater control. Using the data gathered during 

the permit review assisted EPA in: 

1. Assessing the current state of deicing stormwater control; 

2. Evaluating the effectiveness of various deicing stormwater control measures; and 

3. Identifying potential measures that EPA could use to further control deicing 

stormwater. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

15 

Table 3-3. Airports Selected for Sampling and the Reason for Their Selection 

Airport Name 

Airport 

Code 

Dates of 

Sampling Reason for Sampling Sample Points 

Detroit Metropolitan 

Wayne County 

Detroit, MI 

Episode 6508 

DTW 3/31/05 Collects highly 

concentrated ADF for 

recycling, significant 

stormwater volumes, 

direct and indirect 

discharger 

• Untreated deicing stormwater 

• Effluent from ADF-contaminated 

stormwater collection pond 

• Effluent from pavement deicer 

stormwater collection pond 

• ADF, as applied 

• Quality control (QC) samples 1

Minneapolis/St. Paul 

International 

Minneapolis/St. Paul, 

MN 

Episode 6509 

MSP 4/28/05 On-site collection and 

recycling facility, direct 

and indirect discharger 

• High concentration ADFcontaminated stormwater storage 

tank 

• Low concentration ADFcontaminated stormwater storage 

tank 

• Influent to pavement deicer 

stormwater collection pond 

• Effluent from pavement deicer 

stormwater collection pond 

• ADF, as applied 

• QC samples 1

Albany International 

Albany, NY 

Episode 6523 

ALB 2/5/06-

2/10/06 

Reported recovery 

efficiency of 72% of 

applied ADF through 

collection and treatment 

(anaerobic and aerobic) 

of ADF-contaminated 

stormwater 

• Influent to anaerobic treatment 

• Effluent from anaerobic treatment 

• Effluent from aerobic treatment 

• QC samples 1

Pittsburgh 

International 

Pittsburgh, PA 

Episode 6528 

PIT 2/26/06-

3/3/06 

Reported recovery 

efficiency of 60-66% of 

applied ADF through 

collection and treatment 

(ultrafiltration and 

reverse osmosis (RO)) of 

ADF-contaminated 

stormwater 

• Influent to RO treatment 

• Effluent from RO treatment 

• QC samples 1

Denver International 

Denver, CO 

Episode 6522 

DEN 3/26/06-

3/31/06 

ADF-contaminated 

stormwater collection 

with glycol recovery 

• Influent to mechanical vapor 

recompressions (MVRs) 

• Influent to distillation column 

• Distillate from MVRs 

• Overhead from distillation column 

• Effluent from treatment 

• QC samples 1

Greater Rockford 

Rockford, IL 

Episode 6529 and 6530 

RFD 4/20/06 

and 

8/29/06 

On-site aerated lagoon 

treatment system (run in 

batch mode) for its 

deicing-contaminated 

stormwater 

Spring Sampling

• Influent to aerobic pond treatment 

• QC samples 1

Summer Sampling

• Effluent from aerobic pond 

treatment 

• QC samples 1
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

16 

3.5.1 Airport Selection for Permit Review 

For this review, EPA selected the top 50 U.S. airports based on ADF usage. At the time 

of review, usage estimates from the airline survey were not available; therefore, EPA estimated 

the airports with the highest usage using a “weighting factor” based on the number of snow or 

freezing precipitation (SOFP) days and commercial departures as a measure of ADF usage. 

Table 3-4 displays the results of the weighting factor analysis and lists the 50 airports for which 

EPA reviewed permits. 

3.5.2 Obtaining NPDES Permits 

From the list of selected airports for permit review, EPA identified those for which it 

already had permits. While airports were not required to submit permits as part of their 

questionnaire response, some airports did so. Furthermore, there were some permits already 

available in the airport deicing record files. Therefore, as a first step, EPA reviewed available 

documentation and survey responses to identify in-house permit availability. 

As a next step, EPA identified NPDES permit numbers for those permits not available inhouse. Some airports reported permit numbers in the airport questionnaire, so in these cases, 

EPA obtained the data from the questionnaire database. For the remaining airports, EPA 

searched its Envirofacts search tool by facility name, location, SIC code (4581), or a 

combination of any of the three to obtain the permit numbers. 

After identifying the permit numbers, EPA obtained a copy of the permit from a state or 

regional permit database. If a permit was not available online, EPA contacted the appropriate 

regional, state, or local permitting authority to obtain a copy. If still unsuccessful in obtaining the 

permit, EPA contacted the airport directly to request a copy. 

There were a few airports for which EPA could not identify permit numbers from either 

the questionnaires or Envirofacts. For these airports, EPA searched the Internet or contacted 

permitting authorities or the airports directly to obtain a copy of the permit. 

3.5.3 Permit Review Process 

The objectives of the permit review were to answer the following questions: 

• What are the monitoring requirements for deicing area outfalls? 

• What pollutants are monitored? 

• Are there numeric limits listed in the permit for deicing area outfalls? 

• What parameters are limited? 

• What are the limits for each parameter? 

• How were the limits developed? 

• Are there deicing operation best management practices (BMPs) required by the 

permit? 

• What BMPs are required? 

• When does the permit expire? 

• If it is a general permit, are there differences between the permit and the EPA 

Multi-Sector General Permit (MSGP)? 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category Section 3 – Data Collection Activities 

17 

Table 3-4. Top 50 Airports in the United States with the Highest ADF Usage, Estimated Based on SOF

Airport Departures 

Rank 

Airport 

ID Airport Code Airport Name State SOFP Days 

Total Airpo

Departure

1 1006 ORD Chicago O'Hare International IL 26 467,721 2 1126 MSP Minneapolis /St Paul International – WoldChamberlain MN 41 246,286 3 1138 DTW Detroit Metropolitan Wayne County MI 31 250,629 4 1028 DEN Denver International CO 26 264,051 5 1012 ANC Ted Stevens Anchorage International AK 55 88,126 6 1053 BOS General Edward Lawrence Logan International 

(Boston) 

MA 26 186,253 

7 1113 CVG Cincinnati/Northern Kentucky International KY 17 247,165 8 1069 CLE Cleveland – Hopkins International OH 36 116,569 9 1142 IAD Washington Dulles International DC 17 238,635 

10 1107 PIT Pittsburgh International PA 31 125,143 11 1145 EWR Newark Liberty International NJ 16 203,082 12 1095 MDW Chicago Midway International IL 26 108,385 13 1139 PHL Philadelphia International PA 12 227,749 14 1136 MKE General Mitchell International (Milwaukee) WI 31 85,128 15 1029 LGA La Guardia (New York City) NY 12 192,127 16 1066 SLC Salt Lake City International UT 14 160,472 17 1010 FAI Fairbanks International AK 89 24,919 18 1011 STL Lambert - St Louis International MO 17 129,414 19 1148 MCI Kansas City International MO 27 76,016 20 1021 BUF Buffalo Niagara International NY 48 41,916 21 1089 JFK John F Kennedy International (New York City) NY 12 154,606 22 1024 IND Indianapolis International IN 21 83,769 23 1141 DCA Ronald Reagan Washington National DC 12 134,346 24 1129 BDL Bradley International (Windsor Locks) CT 31 51,389 25 1059 ROC Greater Rochester International NY 44 35,726 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category Section 3 – Data Collection Activities 

Table 3-4 (Continued) 

18 

Rank 

Airport 

ID Airport Code Airport Name State SOFP Days 

Total Airpo

Departure

26 1111 CMH Port Columbus International OH 26 59,938 27 1036 BWI Baltimore - Washington International MD 12 124,033 28 1026 DFW Dallas/Fort Worth International TX 4 360,933 29 1065 ALB Albany International NY 36 39,324 30 1080 SYR Syracuse Hancock International NY 44 30,840 31 1140 MEM Memphis International TN 8 166,910 32 1128 CLT Charlotte/Douglas International NC 6 214,396 33 1079 MHT Manchester NH 36 34,860 34 1058 GRR Gerald R Ford International (Grand Rapids) MI 48 25,015 35 1037 IAH George Bush Intercontinental (Houston) TX 4 248,339 36 1123 DAY James M Cox Dayton International OH 26 35,709 37 1020 ATL Hartsfield - Jackson Atlanta International GA 2 459,765 38 1121 PVD Theodore Francis Green State (Providence) RI 21 43,671 39 1147 RDU Raleigh - Durham International NC 10 86,302 40 1068 OMA Eppley Airfield (Omaha) NE 26 33,022 41 1105 GEG Spokane International WA 31 27,269 42 1108 SDF Louisville International - Standiford Field KY 12 65,586 43 1124 DSM Des Moines International IA 31 23,951 44 1074 SBN South Bend Regional IN 48 13,722 45 1153 CAK Akron - Canton Regional OH 41 14,911 46 1109 ILN Airborne Airpark (Wilmington) OH 21 25,508 47 1018 GSO Piedmont Triad International (Greensboro) NC 14 38,257 48 1100 TOL Toledo Express OH 36 14,385 49 1022 FWA Fort Wayne International IN 31 16,247 50 1051 HYA Barnstable Municipal - Boardman/Polando Field 

(Hyannis) 

MA 26 18,782 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

19 

EPA also consulted Envirofacts as necessary to fill in any numeric limit data gaps from 

the permits and to cross-check for accuracy with the permitted limits. 

To facilitate interpreting the results, EPA created a Microsoft® Access database to store 

the data obtained from the reviews. The database consists of two tables: a General Information 

table, and a Pollutant-Specific Information table. Table 3-5 and Table 3-6 detail the database 

table descriptions. A summary of the permit review is presented in the memorandum Airport 

Deicing Operations NPDES Permit Review Summary (ERG, 2007). 

Table 3-5. Permit Review General Information Table 

Data Element Data Element Description 

AirportID The airport identification number used for the Airport Questionnaire 

Permit_ID The airport NPDES identification number 

Permit_Expiration The permit expiration date 

Permit_BMPs A checkbox that identifies the presence of BMPs in the permit 

Permit_BMPs_Description A field that allows the BMPs in the permit to be listed 

General_Permit A checkbox that identifies general permits 

General_Permit_Difference 

from MSGP 

A field that describes any differences that exist between general permits and the 

MSGP 

Permit_Monitoring A checkbox that indicates if the permit requires monitoring 

Permit_Limits A checkbox that indicates if the permit has numeric limits 

Permit_Limit_Rationale A field that describes what rationale was used to determine the limits in the permit 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

20 

Table 3-6. Permit Review Pollutant-Specific Information Table 

Data Element Data Element Description 

AirportID The airport identification number used for the detailed airport questionnaire. 

Permit_SamPoint The outfall/sampling area identifying number. 

Permit_Stream_Description The description of the outfall/sampling area. EPA tried to determine which outfalls 

receive deicing stormwater and to include only information from those outfalls. If 

the deicing outfalls cannot be determined, EPA included all outfalls. 

Permit_Pollutant The pollutants that are monitored and/or limited at each outfall, using the following 

same codes that are used in the questionnaire database: 

• BOD 

• COD (chemical 

oxygen demand) 

• Fecal coliform 

• Metal 

• N (nitrogen) 

• OG (oil & 

grease) 

• ORG (organic 

pollutants) 

• pH

• TOC (total 

organic carbon) 

• TSS 

• Other 

OtherDesc If a pollutant is monitored/limited that does not have a code, “Other” was selected 

as the Permit_Pollutant and the pollutant name was entered in this field. This 

method of tracking pollutants was used to be consistent with the questionnaire 

database. 

PermitTimes To be consistent with the questionnaire database, the frequency of monitoring for 

each pollutant and outfall was recorded in the PermitTimes and PermitFreq fields. 

These fields allow the frequency to be reported in a number/unit manner. For 

example, a yearly report is entered as PermitTimes = 1 and PermitFreq = Year. 

Frequency Codes were also used in the PermitFreq field for daily (D), monthly 

(M), and quarterly (Q) reports. 

PermitFreq 

PermitLimitNumeric The numeric value of the permit limit for each pollutant and outfall. 

PermitLimitUnit The unit of the permit limit for each pollutant and outfall. 

LimitType Indicates whether the limit is a minimum value, maximum value, average, or 

simply a reporting requirement. This also incorporates the time span of the limit 

using the frequency codes as above (e.g., daily maximum = DMAX; weekly 

average = WAVG). 

Season For deicing outfalls, the limits may vary by season for various parameters. Usually, 

this field is populated with Summer, Winter, or All (as in year-round). 

3.6 Deicing Pad Costs 

To evaluate the potential financial impacts of deicing pads for new airports, EPA 

reviewed deicing pad cost information received from airports. EPA collected deicing pad costs 

from Pittsburgh International airport and Minneapolis/St. Paul airport during the site visits, and 

information was provided by Akron-Canton Regional airport via email on May 3, 2007, and 

from Cleveland-Hopkins International airport as part of comments in its airport questionnaire 

response. 

3.7 Industry-Submitted Data

Based on airport site visits, EPA sampling episodes, and responses to the airport 

questionnaire, EPA requested costing and long-term analytical data for managing deicing 

stormwater from specific airports. The Agency used this information to develop control 

technology options and compliance cost estimates, and to evaluate pollution prevention and best 

management practices. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

21 

Table 3-7 and Table 3-8 list those airports providing data, the type of system used to 

manage or treat the airport’s deicing stormwater, and the costing and/or analytical data submitted 

by the airport. 

Table 3-7. Summary of Costing Data Provided by Industry 

Airport 

Type of Deicing Stormwater 

Management Costing Data Provided 

Akron-Canton Regional Anaerobic ADF-contaminated 

stormwater treatment system 

Capital and operating and maintenance costs 

for the airport’s new anaerobic fluidized bed 

(AFB) treatment system 

Albany International AFB/aerobic ADF-contaminated 

stormwater treatment system 

Capital and operating and maintenance costs 

for the airport’s AFB/aerobic treatment system

Cincinnati/Northern 

Kentucky International 

Glycol recovery and recycling 

system 

Capital and operating and maintenance costs 

for glycol collection and treatment 

Denver International Storage, recovery, and recycling; 

MVR and distillation system 

Capital costs for storage and the 

recycle/recovery system 

General Mitchell 

International 

Recovery and recycling; anaerobic 

digester 

Engineering and monitoring-related costs 

Minneapolis/St. Paul 

International –Wold 

Chamberlain 

ADF collection (deicing pads, plug 

and pump system) 

Capital costs for deicing pads and operating 

and maintenance costs for plug and pump 

system 

Pittsburgh International ADF collection at deicing pads; 

ADF-contaminated stormwater 

recovery and recycling 

Operating and maintenance costs for deicing 

pads

Seattle-Tacoma International ADF to industrial waste treatment 

plant 

Study costs for determining all known and 

reasonable technology (AKART) for handling 

aircraft deicing fluids 

Table 3-8. Summary of Long-Term Analytical Data Provided by Industry 

Airport 

Type of Deicing Stormwater 

Management 

Long-Term Analytical Data 

Provided 

Albany International Anaerobic/aerobic ADF-contaminated 

stormwater treatment 

Ammonia, COD 

Denver International Storage, recovery, and recycling; 

MVR/distillation 

COD 

Detroit Metropolitan – 

Wayne County 

Recycling; distillation and recovery Ammonia 

Pittsburgh International Ultrafiltration/Reverse Osmosis; ADFcontaminated stormwater recovery and 

recycling 

Ammonia, urea 

Salt Lake City International ADF recovery and recycling COD 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

22 

3.8 Literature Reviews

EPA conducted preliminary literature searches during the effluent guideline development 

process to supplement information acquired from site visits, sampling, and questionnaires. The 

purpose for the literature searches was three-fold: 

• To collect information on current airport deicing practices and trends, and gather 

information on state-of-the-art deicing stormwater treatment and/or glycol 

recovery technologies; 

• To collect available data from airports currently monitoring wastewater 

discharges; and 

• To obtain studies on the toxicity and environmental impact of current deicing 

fluids and deicing discharges. 

The following sections list the data sources used for each literature search. 

3.8.1 Current Deicing Practices and Treatment Technologies 

EPA performed keyword searches on three online search engines: 1) Cambridge 

Scientific Abstracts (CSA); 2) Dialog Version 5.0; and 3) GoogleTM. CSA provides access to 

over 50 databases published by CSA and its publishing partners, such as Aqualine, 

Environmental Sciences & Pollution Management Database, and Water Resources Abstracts. 

Dialog provides access to over 900 databases and handles more than 700,000 searches. The 

databases in Dialog that contain articles pertaining to airport deicing are BIOSIS Toxicology, 

Life Sciences Abstracts, Institute for Science Information, ProQuest Info & Learning, Ei 

Compendex, Enviroline, TGG National Newspaper Index, GeoBase, National Technical 

Information Service (NTIS), and Wilson Applied Science & Technology Abs. 

The keywords for the literature searches included: airport deicing, aircraft, airfield, 

runway, aircraft deicing, aircraft deicing fluid (ADF), runway deicing, anti-icing, anti-icing fluid, 

airport stormwater, snow melt, centralized deicing pads, environmental assessment, 

environmental impact study (EIS), fish mortality, fish kill, and publicly owned treatment works. 

EPA also used other online journal databases, such as Science Direct, Scirus, and 

Infotrak, for subject-specific articles. The treatment technologies featured in the articles found 

included: 

• AFB reactor/ biological treatment; 

• Aerated storage tanks; 

• Anaerobic co-digestion of ADF and municipal wastewater sludge; 

• Batch-loaded AFB reactor; 

• Glycol reclamation/recycling and concentration; 

• Infrared technology; 

• Phytoremediation; 

• Plant-enhanced remediation; 

• Spray irrigation; 

• Subsurface-flow constructed wetlands; and 

• Surface detention ponds. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

23 

3.8.2 Current Airport Deicing Discharge Data 

In addition to sampling and airport questionnaire data, EPA procured airport deicing 

discharge information from its Permit Compliance System (PCS) database and online journals. 

EPA downloaded all data reports from PCS for SIC code 4581: Airports, flying fields, and 

services. Not all airports report this data to their permitting authority, so the scope of discharge 

data is limited. The pollutant parameters include temperature, dissolved oxygen, BOD, TSS, 

metals, fecal coliform, aromatic hydrocarbon, pH, and oil and grease. For online searches, EPA 

procured journals that discussed deicing discharge containing ADF chemicals such as 

benzotriazole, propylene/ethylene glycol, and alklyphenol ethoxylates. EPA also collected 

monitoring data during the site visit to the Minneapolis/St. Paul International Airport.

3.8.3 Chemical Information and Environmental Impact Studies 

The methodology and databases used for chemical information and environmental impact 

study findings are similar to those used for the deicing practices and treatment technology 

search. EPA conducted searches for the following categories: 

• Chemical Properties of ADF Ingredients: Physical appearance, structure, 

solubility, reactivity; 

• Human Toxicity: Inhalation, ingestion, dermal effect, oral rat lethal dose (LD50) 

values; 

• Aquatic Toxicity: Aquatic life lethal concentration (LC50) values; and 

• Chemical Fate and Transport: Soil sorption, fate in river, streams, and 

estuaries, breakdown pathways in anaerobic and aerobic conditions, and 

biodegradability. 

In addition to journal articles, EPA gathered chemical information from Material Safety 

Data Sheets (MSDSs), Chemfinder.com, the Pesticides Action Network (PAN) Pesticides 

Database, and the U.S. Patents Database. 

The keywords for the pollutant term search included: PG, PG-based fluids, EG, EG-based 

fluids, urea, potassium acetate, calcium magnesium acetate (CMA), sodium acetate, sodium 

formate, dissolved oxygen, biodegradation, BOD, and ADF additives (e.g., tolytriazole, 

benzotriazole, nonylphenols, nonylphenol ethoxylate, etc.). 

3.8.4 Current Deicing Discharge Regulations 

In addition to the data sources described above, EPA searched the Internet using 

GoogleTM to review regulatory documents that contain guidelines, operation controls, 

management programs, laws, statutes, and certification requirements related to airport deicing 

from the United States, Canada, Germany, Norway, and other European countries. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

24 

3.9 Data Collected Based on Public Comments

EPA collected and received limited additional information as part of the public comment 

process. This section summarizes the information EPA collected as part of and in response to 

public comments on the proposed rule and the types of data provided as part of the public 

comments. Section 3.9.1 summarizes information that EPA collected to confirm deicing pad use 

and operations at major airports and data collected to supplement the costing effort in response to 

comment. Section 3.9.2 summarizes the types of data submitted as part of the public comments 

to the proposed rule. 

3.9.1 EPA-Collected Data 

EPA received comments on the proposed regulation that airports that had previously 

installed deicing pads did not use them for all flights that required deicing. EPA contacted the 

following airports in early August 2010 to confirm information on the airport’s deicing pad use 

and operations: 

• Minneapolis/St. Paul International Airport (MSP); 

• Washington Dulles International Airport (IAD); 

• Philadelphia International Airport (PHL); 

• Detroit Metropolitan/Wayne County Airport (DTW); 

• Denver International Airport (DEN); 

• Cleveland-Hopkins International Airport (CLE); 

• Salt Lake City International Airport (SLC); and 

• Pittsburgh International Airport (PIT). 

Table 3-9 summarizes the information collected for these airports. 

EPA also collected additional post-proposal information as part of revisions to the costing 

analysis in response to specific public comments. Additional costing information collected by 

EPA included drainage cover data that it used in conjunction with existing cost data for Glycol 

Collection Vehicles (GCVs). The supplemental data collected to inform GCV costing is 

summarized in a memorandum entitled Estimated Capital and Operation and Maintenance Costs 

for Glycol Collection Vehicle Operation (ERG, 2010a). EPA also collected vendor data related 

to liquid application and storage of airfield deicing chemicals. These data are summarized in the 

memorandum entitled Estimated Costs for Transition to Liquid Airfield Deicing Application 

from Solid Airfield Deicing (ERG, 2010b). In addition, Section 10 presents the liquid application 

and storage of airfield deicing chemical cost data used in developing the final rule cost analysis. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

25 

Table 3-9. Selected Airport Information Related to Deicing Pad Operations 

Airport Deicing Pad Operations Data 

Minneapolis/St. Paul 

International Airport 

1. MSP encourages the use of deicing pads and requires deicing in contained 

locations only. ADF stormwater is contained through deicing pad use (and its 

collection system), block and pump, and cover and sweep (using glycol collection 

vehicles). There are no exceptions to the requirement for contained locations for 

deicing operations. 

2. MSP estimates that 65-70% of ADF fluid used at the airport is sprayed at its 

deicing pads. The percentage of flights represented by this amount of ADF fluid use 

is much lower than 65-70%. The deicing pads are typically used for heavy deicing 

and not for defrost deicing. Delta, previously Northwest Airlines, deices at both the 

gate and at the deicing pads. Overall, they spray more deicing fluid at the pads than 

at the gates. This airline does not generally act as an FBO for other airlines but may 

be used as a deicing provider in a backup situation. The small airlines operating at 

the airport do not have personnel for deicing pad use. 

3. If deicing is not done on the deicing pads, it is done at the gate. 

4. Advantages of the MSP deicing pads include putting the deiced aircraft closer to 

the runway, which lowers the chance of missing ADF holdover times, and freeing 

up the gates for incoming flights. 

Washington Dulles 

International Airport 

1. Approximately 50% of the flights deiced at IAD are deiced on deicing pads. In 

addition, the airport requires that flights be deiced in areas of capture that may 

include glycol collection vehicles. 

2. There are no specific requirements on where each airline has to deice their 

planes. The location of where each airline plans to deice is decided between the 

airlines at winter "snow meetings." 

Philadelphia International 

Airport 

1. All commercial aircraft except commuter aircraft (regional jets and turbo-props) 

must be deiced at the airport deicing pad, as specified in the airport’s NPDES 

permit. 

2. Aircraft defrosting is permitted at the gates with a usage limit of 20-40 gallons of 

ADF, as specified in the airport’s NPDES permit. 

3. Deicing of the plane is also permitted at the gate with no ADF usage limit, for 

required weight reduction or visibility enhancement, sufficient to safely taxi the 

aircraft to the deicing pad for final, pre-take-off ADF application. 

Detroit 

Metropolitan/Wayne 

County Airport 

1. DTW does not have a specific requirement forcing the airlines to deice aircraft at 

the deicing pads but does strongly encourage deicing pad use. 

2. The airport estimates that approximately 90% of the airport traffic that is deiced 

uses the deicing pads. 

3. The airport allows 747s to deice at the gates to free up the deicing pads for 

smaller aircraft. Airport study of this allowance shows that it achieves a higher net 

capture of ADF using this approach. The airport collects ADF stormwater from the 

747 deicing using a glycol collection vehicle in conjunction with catch basin 

inserts. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

Table 3-9 (Continued) 

26 

Airport Deicing Pad Operations Data 

Denver International 

Airport 

1. DEN does not allow full-plane gate deicing, and does not track limited gate 

deicing operations specifically (other than to enforce the 25-gallon rule discussed in 

item 3. below). The airport tracks only the volume of fluid used on an airport-wide 

basis but estimates that 95% of deicing occurs on the dedicated deicing pads. DEN's 

largest carrier, United Airlines (UAL), does provide DEN (Environmental Services) 

with its fluid usage data, including by location. UAL's data show approximately 6% 

of its total fluid used was applied at the gates pursuant to DEN's 25-gallon 

operational allowance. UAL's data do not provide the number of flights deiced by 

location. On average, UAL accounts for approximately 27% of the total aircraft 

deicing fluid applied at DEN. 

2. DEN is not aware of any specific instances of deicing outside the designated 

areas (pads, gates (limited), GA, South Cargo). If it did occur, it would be a very 

rare occurrence under special circumstances, and would require prior approval from 

the Manager of Aviation. 

3. Limited deicing requirements are stipulated on page 6 of DEN Rule and 

Regulation Part 190 - Aircraft Deicing Regulations. The language does not specify 

for what purpose limited deicing may occur, only that "In no event may the total 

amount of deicing fluid used in a limited deicing exceed 25 gallons neat (undiluted) 

ADF per aircraft.” DEN R&R Part 190 can be accessed directly at 

http://business.flydenver.com/info/research/rules/index.htm. 

4. On a volume-only basis, for the 2008/2009 season, DEN data show 

approximately 5% of the total amount of deicing fluid used at DEN was applied at 

South Cargo and General Aviation (combined). 

Cleveland-Hopkins 

International Airport 

1. CLE estimates that 90% of deiced flights are deiced at deicing pads and the 

remaining 10% are deiced at the gate. Most of the air carriers are not allowed to 

deice at the concourse gates. 

2. For those air carriers not allowed to deice at the gate, the airport does allow 

emergency deicing to unfreeze the wheels or other plane parts to allow the plane to 

move safely to the deicing pad. 

Salt Lake City 

International Airport 

1. At SLC, 95-98% of the deiced flights are deiced on pads and each major airline 

has its own dedicated deicing pad. 

2. All deicing is to occur on the deicing pads except for specific circumstances that 

are typically delay related. 

Pittsburgh International 

Airport 

1. Aircraft deicing at the airport is required by consent decree to occur on deicing 

pads. Thus, 100% of deiced flights are deiced on the airport's pads unless doing so 

will result in a total loss of operations (e.g., major delays or if the deicing pad is out 

of ADF). The airport does allow gate deicing for both defrost and safety purposes. 

2. PIT defines defrost deicing as "the removal of contamination (frost) from critical 

components of the airport that occurs when there is no active precipitation" and 

defines regular deicing as “the removal of contamination (snow/ice) that occurs 

when there is or has been active precipitation." 

3. When an air carrier conducts gate deicing (instead of using the deicing pads), it 

must document why the deicing occurred at the gate. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 3 – Data Collection Activities 

27 

3.9.2 Data Submitted with Public Comments 

All comments received on the proposed airport deicing rulemaking are available in the 

docket. In assessing comments, EPA evaluated, and in some cases used, data or suggestions 

provided by specific commenters for the final rule analyses. While the data submitted by 

commenters were useful, in general, commenters provided very little analytical data on treatment 

or collection performance. Commenters, however, did provide some new data related to the 

costing analysis and on the feasibility of deicing pads. Section 10 summarizes the data used to 

develop EPA’s final rule costs. As an example, EPA incorporated industry-supplied data on AFB 

capital costs versus COD loading in its final costing analysis (see Figure 10-1). 

Comments by specific airports/port authorities on the proposed rule, including BostonLogan International Airport and The Port of New York and New Jersey, included documentation 

supporting a claim that their airports are space-constrained and they would not be able to locate a 

deicing pad facility to comply with the proposed rule. EPA considered this data in developing the 

final rule and is no longer requiring collection of spent ADF at existing airports. 

3.10 References

ERG. 2007. Memorandum from Jason Huckaby (ERG) to Brian D’Amico and Eric Strassler 

(U.S. EPA). Airport Deicing Operations NPDES Permit Review Summary. (April 16). DCN 

AD00611. 

ERG. 2010a. Memorandum from Steve Strackbein and Mary Willett (ERG) to the Airport 

Deicing Administrative Record. Estimated Capital and Operation and Maintenance Costs for 

Glycol Collection Vehicle Operation. (October 8). DCN AD01249. 

ERG. 2010b. Memorandum from Steve Strackbein and Mary Willett (ERG) to Brian D’Amico 

and Eric Strassler (U.S. EPA). Estimated Costs for Transition to Liquid Airfield Deicing 

Application from Solid Airfield Deicing. (October 8). DCN AD01252. 

USEPA. 2000. Preliminary Data Summary: Airport Deicing Operations. U.S. Environmental 

Protection Agency. Washington, D.C. EPA-821-R-00-016. Available online at 

http://www.epa.gov/guide/airport . DCN AD00005. 

USEPA. 2005. Supporting Statement: Survey of Airport Deicing Operations. U.S. Environmental 

Protection Agency. Washington, D.C. DCN AD00447. 

USEPA.2008a. Airline Screener Questionnaire Database. U.S. Environmental Protection 

Agency. Washington, D.C. DCN AD00937. 

USEPA. 2008b. Airline Detailed Questionnaire Database. U.S. Environmental Protection 

Agency. Washington, D.C. DCN AD00938. 

USEPA. 2008c. Airport Questionnaire Database. U.S. Environmental Protection Agency. 

Washington, D.C. DCN AD00927. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

28 

4. OVERVIEW OF THE INDUSTRY

This section provides an overview of the airport deicing/anti-icing performed by selected 

airports and airlines. The overview includes statistics on the number and location of airports and 

airlines that perform deicing/anti-icing (Section 4.1) and deicing and anti-icing practices 

performed on airfields and aircraft and methods used to collect and control deicing stormwater 

(Section 4.2). 

4.1 Industry Statistics

Data sources for statistics on the number and types of airports and airlines include 

responses to EPA’s airport and airline questionnaires, the Bureau of Transportation Statistics, 

FAA, and EPA’s Preliminary Data Summary: Airport Deicing Operations (PDS) (USEPA, 

2000). Data provided in responses to EPA questionnaires are based on deicing/anti-icing 

operations performed during the winter seasons of 2002/2003, 2003/2004, and 2004/2005, 

hereafter referred to as the three winter seasons. 

4.1.1 Airports 

The North American Industry Classification System (NAICS) identification number 

applicable to airport deicing is 488119: Other Airport Operations. The U.S. Census Bureau 

describes this industry as establishments primarily engaged in the following: (1) operating 

international, national, or civil airports or public flying fields, or (2) supporting airport 

operations, such as runway maintenance services, hangar rental, and/or cargo handling services. 

The airport questionnaire data presented in this section are based on the 150 respondents 

to EPA’s airport questionnaire. EPA applied weighting factors to the information provided by 

selected airport questionnaire recipients to scale up the questionnaire data to represent national 

estimates. 

4.1.1.1 Number and Types of Airports 

FAA’s general categories of airports include commercial, general aviation, and relievers. 

Commercial airports are public airports receiving scheduled passenger service and having more 

than 2,500 enplaned passengers (number of passengers boarding a plane for departure) each year. 

General aviation airports have less than 2,500 enplanements per year or do not receive scheduled 

commercial service. Relievers are high-capacity general aviation airports in major metropolitan 

areas, and provide an alternative for small aircraft using busy commercial airports. 

Airports may be further classified into several different categories, depending on the size 

and activity level of the airport. Often both of these factors can be determined by the number of 

enplanements or operations (number of arrivals and departures) at the airport in a given year. 

FAA classifies large commercial airports into “hubs,” based on the number of annual 

enplanements that occur at the airport. Large Hubs are defined as airports with more than 1 

percent of total U.S. passenger enplanements. Medium Hubs are defined as airports with more 

than 0.25 percent but less than 1 percent of total passenger enplanements. Small Hubs account 

for 0.05 to 0.25 percent of the total passenger enplanements. Airports with less than 0.05 percent 

of the total passenger enplanements but more than 10,000 annual enplanements are considered 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

29 

Non-hub primary airports. Nonprimary commercial services are those airports that have 2,500 to 

10,000 enplanements a year. 

According to FAA 2004 data and the FAA’s National Plan of Integrated Airport Systems 

(NPIAS) Report to Congress, about 3,344 airports operated in the United States in 2004. Table 

4-1 identifies the number of airports by type as defined by number of enplanements. For all 

airport types, excluding general aviation airports, the totals in Table 4-1 represent counts for 

January through December 2004. FAA’s designation of hub status depends on the percentage of 

total passenger boardings occurring at each airport, causing the number of airports in each hub 

category to vary from year to year. 

Table 4-1. Number of U.S. Airports by Airport Type in 2004 

Airport Type Number of Airports 

Large Hub 33 

Medium Hub 36 

Small Hub 67 

Non-hub 231 

Other Nonprimary 130 

General Aviation 1 2,573 

General Aviation Relievers 1 274 

TOTAL 3,344 

1 General aviation and general aviation reliever airports (open to the public) from the NPIAS Report to Congress 

(USDOT, 2008a). 

Note: Airport counts will differ depending on the source and year of data represented. 

EPA distributed the airport questionnaire to 153 airports that included, based on 2004 

information, all Large Hub, all Medium Hub, and a statistical sampling of Small Hub and Nonhub airports, as well as judgment sampling of some general aviation/cargo, and other nonprimary 

airports. EPA determined that one airport recipient was out of scope and removed it from the 

sample frame. EPA received responses from 150 of these airports. Using the airport responses 

and their statistical weights and including the cargo airports and Alaskan airport judgment 

samples, EPA estimated that the number of primary commercial airports nationally that perform 

deicing and/or anti-icing of airfield pavement and/or aircraft is 334. 

4.1.1.2 Geographic Location of Deicing Airports 

The location of the airport and its climate have a direct impact on deicing operations. 

Airport deicing/anti-icing operations occurred in 44 states in the three winter seasons. As shown 

below, the FAA divides the United States into the following nine regions: 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

30 

Region State 

Alaskan AK 

Central IA, KS, MO 

Eastern DE, MD, NJ, NY, PA, VA, WV 

Great Lakes IL, IN, MI, MN, ND, OH, SD, WI 

New England CT, ME, MA, NH, RI, VT 

Northwest Mountain CO, ID, MT, OR, UT, WA, WY 

Southern AL, FL, GA, KY, MS, NC, PR, TN, VI 

Southwest AR, LA, NM, OK, TX 

Western-Pacific AZ, CA, HI, NV, GU, AS, MH 

Source: FAA, “FAA Regional Offices,” http://www.faa.gov/about/office_org/headquarters_offices/arp/

regional_offices/ (U.S. DOT, 2008b). 

Table 4-2 summarizes the regions for the airports that reported deicing in the EPA airport 

questionnaire for the three winter seasons surveyed by EPA. (Note: these are not national 

estimates.) The Great Lakes and Eastern regions reported the highest number of deicing airports. 

Table 4-2. Deicing Airports by FAA Region for the Three Winter Seasons 

Region 

Airports Reporting Deicing and/or Anti-Icing in EPA 

Airport Questionnaire 

Great Lakes 31 

Eastern 22 

Southern 20 

Northwest Mountain 17 

Western-Pacific 15 

Southwest 14 

Alaskan 10 

New England 6 

Central 5 

Source: EPA airport questionnaire database (USEPA, 2008c). 

4.1.1.3 Weather Impacts on Airport Deicing/Anti-Icing 

Airports conduct deicing/anti-icing operations when weather conditions, such as 

precipitation and/or temperature, have the potential to cause icing. Precipitation includes 

snowfall, rainfall, sleet (including freezing rain), and ice. The type of precipitation affects the 

volume and type of deicing/anti-icing chemicals used on aircraft and airfield pavement. For 

example, freezing rain requires the most deicing/anti-icing agent usage because the rain freezes 

on contact and coats the aircraft or airfield pavement to form a solid layer of ice. Dry-weather 

deicing, performed when the ambient temperature is cold enough to form ice on aircraft wings 

and surfaces (below 55° F), generally requires only a small volume of ADF. 

The duration of the deicing/anti-icing season is also determined by the climate at an 

airport location. Airfield pavement deicing can begin as early as September and continue through 

May in colder climates and/or areas with high numbers of snow or freezing precipitation days. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

The national estimate of airports performing airfield pavement deicing is 215; this is lower than 

the national estimate of airports performing deicing operations overall because there are airports 

that have some aircraft deicing (usually defrost deicing) but no airfield pavement deicing. In 

general, these airports are located in warm and/or dry weather climates with minimal winter 

storm events. For months when airfield pavement deicing occurs, December, January, and 

February have the most occurrences of airfield pavement deicing, and September and May have 

the lowest. Figure 4-1 presents the percentage of these 215 airports deicing airfield pavement for 

each month. The time frame during which an airport conducts deicing during a typical winter 

season ranges from two to nine months, and a majority of airports typically conduct deicing/antiicing operations for five months a season. For the three winter seasons surveyed by EPA, the 

average reported number of airfield pavement deicing days among these 215 airports ranges 

from 0.3 to 240 days. 

71%

69%

61%

27%

5%

0% 0% 0%

5%

24%

55%

71%

0%

10%

20%

30%

40%

50%

60%

70%

80%

January

February

March

April

May

June

July

August

September

October

November

December

Month

Percentage

Figure 4-1. Percentage of Airports Deicing Airfield Pavement Each Month

4.1.1.4 Destination of Airport Deicing Stormwater 

Airport questionnaire respondents reported direct, indirect, and zero discharge of deicing 

stormwater. Direct dischargers discharge deicing stormwater directly to U.S. surface waters, 

such as creeks, rivers, ponds, lakes, or oceans. Indirect dischargers convey deicing stormwater by 

pipe, conduit, or hauling to a publicly owned or other treatment works. A zero discharger 

disposes of deicing stormwater using methods other than direct or indirect discharge. Figure 4-2

presents the reported discharge status of airports by destination. Scaling the questionnaire data to 

a national estimate results in 176 airports discharging to surface water only, 52 airports 

31 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

discharging both directly to surface water and indirectly to a POTW, 10 airports discharging to a 

POTW only, and 96 airports reporting zero discharge. 

Direct Discharge 

Only

52%

Direct and 

Indirect 

Discharge

16%

Indirect 

Discharge Only

3%

Zero Discharge

29%

Figure 4-2. Discharge Status of Airports 

A majority of the zero dischargers reported conducting aircraft deicing only (i.e., no 

deicing of airfield pavement). These airports generally are in warm and/or dry weather climates 

and have minimal dry weather (defrost) deicing. Airports reported various methods for 

maintaining zero discharge that included evaporation, storage in surface impoundments, contract 

hauling, and recycle/recovery of deicing stormwater. The most common zero discharge method 

reported was evaporation followed by discharge to a surface impoundment and the “other” 

category. The methods identified as “other” zero discharge techniques included, infiltration, 

discharge to tundra over permafrost, use of drain covers and sorbent material, and use of BMPs. 

Even though over 100 airports indicated that they do not have any direct discharge (96 

zero discharge and 10 POTW only) of ADF-contaminated stormwater, EPA believes that 

fugitive ADF emissions from overspray and tracking and dripping, during taxiing and takeoff, 

are difficult if not impossible to track and will likely result in direct discharges, albeit potentially 

small ones. 

4.1.2 Airlines 

The NAICS code for airlines is 481: Air Transportation. Specific NAICS codes for 

respondents to the airline deicing questionnaires are: (1) 481111: Scheduled Passenger Air 

Transportation, described by the U. S. Census Bureau as establishments primarily engaged in 

providing air transportation of passengers or passengers and freight over regular routes and on 

regular schedules; and (2) 481112: Scheduled Freight Air Transportation, described by the U.S. 

Census Bureau as establishments primarily engaged in providing air transportation of cargo 

without transporting passengers over regular routes and on regular schedules. 

32 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

33 

The airline data presented in this section are based on the 49 respondents to EPA’s airline 

detailed questionnaire and additional information from the 70 respondents to EPA’s airline 

screener questionnaire. Statistics for airlines do not have weighting factors and are based on the 

actual number of respondents. 

4.1.2.1 Types of Airlines 

The four classifications of airlines are major, national, regional, and cargo and are based 

on the type of service they offer and their annual revenues. Classification is based on the 

economic and financial aspects of each airline’s aircraft fleet. Table 4-3 lists the criteria for the 

four classifications. 

Table 4-3. Airline Classifications 

Airline Type Annual Revenues Type of Service Aircraft Fleet 

Major >$100 million Regular schedules Large jets: >60 seats 

Payload >18,000 lbs 

National $100 million to $1 billion Regular schedules Medium and large jets 

Regional: Limited to single U.S. region

Large $20 million to $100 million Scheduled >60 seats 

Medium <$20 million Scheduled Lesser or greater than 60 seats 

Small 

(commuters) 

No revenue cut-off Scheduled <30 seats 

Cargo No revenue cut-off Scheduled Passenger aircraft with seats 

removed 

Source: Preliminary Data Summary: Airport Deicing Operations (Revised) (USEPA, 2000). 

There were 20 major airlines in the United States in 2006. Many national airlines 

typically serve multiple U.S. regions whereas regional airlines are generally limited to a single 

region of the country. 

Small regional airlines are the largest segment of the regional airline business. Regional 

airlines may be private business carriers, commercial airlines, charter airlines, or provide a 

combination of these services. Private business carriers represent about 60 percent of regional 

airline flights. Regional airlines serve all airports served by major airlines as well as smaller 

airports that are not served by any major airline. They typically operate out of one gate area 

unless they are affiliates of major airlines and operate at the gates of their affiliate. Regional 

airlines conduct a disproportionately large number of flight operations per passenger because 

their aircraft are smaller and carry fewer passengers per operation. 

All respondents to the airline detailed questionnaire reported conducting deicing/antiicing operations on their aircraft at a total of 57 airport locations. 

4.1.2.2 Types of Airline/Airport Relationships 

The relationship between airports and airlines regarding deicing operations is one of 

dependency and cooperation. Airports and airlines conduct deicing using chemical and 

nonchemical methods in the same airfield locations and both contribute pollutants to deicing 

stormwater. Airlines may conduct deicing on their own aircraft, deicing for other airlines, and/or 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

34 

may also use FBOs. An airline’s deicing methods must be approved by the FAA for air safety. 

Airports provide the collection and control systems to contain and/or treat deicing stormwater 

generated as a result of aircraft and airfield deicing. However, both airports and airlines 

implement pollution prevention practices such as evaluating application rates, using alternate 

chemicals, pretreating pavement and aircraft, and manually removing snow and ice to reduce the 

quantity of pollutants discharged and the amount of deicing stormwater generated. 

4.2 Industry Practices

Airport deicing and anti-icing operations involve chemical and mechanical methods and 

are conducted at varied locations and by different entities. This section discusses these practices 

and pollution prevention methods used by airports and airlines as reported by respondents to the 

airport and airline deicing questionnaires. 

4.2.1 Airfield Deicing Practices 

Airfield pavement deicing/anti-icing removes or prevents the accumulation of frost, 

snow, or ice on runways, taxiways, aprons, gates, and ramps. These methods are typically 

conducted by airport personnel, FBOs, or private contractors using a combination of mechanical 

methods and chemical deicing/anti-icing agents. To reduce the quantity of pollutants or the 

amount of deicing stormwater generated, airports also use various pollution prevention measures. 

Responses to EPA’s airport questionnaire indicated that 67 percent of airports have the 

primary responsibility for airfield pavement deicing/anti-icing. 

4.2.1.1 Chemical Deicing/Anti-Icing 

The type of precipitation and temperature affect the volume and type of deicing agents 

required for deicing/anti-icing. Common pavement deicing/anti-icing agents used at airports 

include potassium acetate, sand, airside urea, sodium acetate, glycol-based fluids, and sodium 

formate, as reported by respondents to EPA’s airport questionnaire. Potassium acetate and PGbased fluids were reported as the top deicing/anti-icing chemicals (by weight) used on airfield 

pavement during the three winter seasons surveyed by EPA; some respondents also reported 

using a mixture of these agents as well as heated sand. Table 4-4 provides national estimates of 

the number of airports using these agents. Airports purchase primarily ready-to-apply rather than 

concentrated formulations of these chemicals. See Section 6.1 for a detailed discussion of 

deicing chemical usage. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

35 

Table 4-4. National Estimate of Airports Using Deicing Chemicals or Materials 

Deicing/Anti-Icing 

Chemical or 

Material 

Number of Airports Using Deicing Chemical/Material 

Average 

Percentage of 

Airports Using 

Deicing Chemical/

2002/2003 2003/2004 2004/2005 Material 

Potassium Acetate 94 104 111 103 31 

Sand 103 104 98 102 30 

Airside Urea 58 60 59 59 17 

Sodium Acetate 39 34 33 35 10 

PG-Based Fluids 16 16 16 16 5 

Sodium Formate 22 1 23 15 5 

EG-Based Fluids 6 6 6 6 2 

Source: EPA airport questionnaire responses (scaled to national estimates) (USEPA, 2008c). 

4.2.1.2 Mechanical and Nonchemical Deicing/Anti-Icing 

Mechanical methods, such as plows, brushes, blowers, and shovels for snow removal, are 

the primary forms of airfield pavement deicing and may be used in combination with chemical 

methods. One facility uses heated pavement through pavement temperature sensors to prevent 

airfield pavement from icing. All of the 215 airports that conduct pavement deicing use some 

form of chemical, while an estimated 212 (99 percent) use mechanical methods as well on 

airfield pavement. 

4.2.2 Aircraft Deicing Practices 

Aircraft deicing involves removing frost, snow, or ice from aircraft. Aircraft anti-icing 

entails preventing frost, snow, or ice from accumulating on aircraft surfaces. Both chemical and 

nonchemical deicing/anti-icing methods are conducted on aircraft at varied airport locations and 

by different entities. The FAA also influences aircraft deicing, as it has approval authority for the 

deicing/anti-icing practices and procedures selected. Airlines and FBOs also perform pollution 

prevention practices similar to airports to reduce the quantity of pollutants discharged and/or 

reduce the amount of deicing stormwater generated. 

Aircraft deicing may be conducted by an airline, FBO, or private contractor. Often, larger 

airline carriers deice their own aircraft and possibly the aircraft of other airlines. In addition, the 

entity conducting aircraft deicing for an airline may vary depending on the airport location. All 

of the airline questionnaire respondents reported deicing their own aircraft at one or more of their 

airport locations. Airline respondents also reported FBOs and/or another airline deiced their 

aircraft (84 percent and 56 percent, respectively) at some of their airport locations. 

Aircraft deicing is conducted at a variety of airport locations and may be conducted at 

multiple types of locations at the same airport. Aircraft deicing is most commonly performed at 

deicing pads and terminal gates and apron areas. Airline respondents reported aircraft deicing at 

the following locations (the percentage of the airline respondents reporting using the specific 

type of location is in pararentheses): 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

36 

• Deicing pad (80 percent); 

• Passenger terminal gates/apron areas (78 percent); 

• Aircraft parking aprons (46 percent); 

• Airfield ramps (42 percent); 

• Taxiways (24 percent); 

• Cargo apron areas (16 percent); and 

• Other locations (12 percent) (e.g., hangar). 

4.2.2.1 Chemical Deicing/Anti-Icing 

The type of precipitation and temperature influences the volume and type of deicing 

chemicals required to deice/anti-ice aircraft. Two types of aircraft deicing are conducted: wetweather and dry-weather. Wet-weather deicing is conducted when snow, sleet, or freezing rain 

accumulates on the aircraft. Dry-weather deicing is conducted when frost or ice forms on the 

aircraft due to changes in the ambient temperature or when fuel tanks become cooled during 

high-altitude flight, forming ice at lower altitudes and after landing. Dry-weather deicing 

requires significantly smaller volumes of ADFs than wet-weather deicing. 

Aircraft deicing/anti-icing chemicals are categorized into four classes: Type I, Type II, 

Type III, and Type IV. Not all types are currently used. Airlines surveyed by EPA reported 

consistently using only Type I and Type IV fluids. ADFs vary by composition and allowable 

holdover times (i.e., the amount of time the residual fluid protects aircraft from ice formation). 

They generally contain either EG or PG, water, and additives to remove or prevent ice and snow. 

Type I ADF is used to remove ice and snow that has accumulated on aircraft, and Type IV fluids 

are used for anti-icing to increase holdover times for an aircraft prior to takeoff. Deicing fluids 

are usually heated prior to application, while anti-icing fluids are typically applied at ambient 

temperatures. 

All fluids are usually applied under pressure using a nozzle, often from mobile deicing 

trucks (as reported by 31 airlines). Below are additional types of ADF application equipment 

used, as reported in responses to the airline questionnaire: 

• Other equipment (e.g., brooms, ground sprayer and ladder, palletized equipment 

and fork lift, towed tower, small portable unit, self-contained mobile unit); 

• Fixed booms; and 

• Handheld bottle/containers. 

Table 4-5 identifies the types of ADF fluids purchased by airlines that deiced their own 

aircraft during the three winter seasons, as well as the average across those seasons, based on the 

49 airline respondents to the airline detailed questionnaire. Table 4-6 lists the ADF fluids 

purchased by an FBO during the three winter seasons and the average across those seasons, as 

reported in the airline questionnaire. As shown in the tables, Type I and Type IV PG are the most 

commonly purchased ADF fluids for deicing aircraft, both by airlines that deice their own 

aircraft and airlines that use FBOs. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

37 

Table 4-5. Deicing/Anti-Icing Chemicals Purchased by Airlines that Deiced Their Own 

Aircraft 

Deicing/Anti-Icing 

Chemical 

Number of Airlines Purchasing Chemicals Average Number of 

Airlines Purchasing 

2002/2003 2003/2004 2004/2005 Chemicals 

Type I PG 29 29 28 29 

Type IV PG 22 22 23 22 

Type I EG 8 8 8 8 

Type IV EG 6 5 4 5 

Type II PG 0 0 1 1 

Source: EPA airline detailed questionnaire database (USEPA, 2008b). 

Table 4-6. Deicing/Anti-Icing Chemicals Purchased for Aircraft Deiced by an FBO 

Deicing/Anti-Icing 

Chemical 

Number of Airlines for Chemicals Purchased by an 

FBO Average Number of 

Airlines for Chemicals 

2002/2003 2003/2004 2004/2005 Purchased by an FBO 

Type I PG 35 36 39 37 

Type IV PG 31 35 37 34 

Type I EG 17 13 13 14 

Type IV EG 13 9 9 10 

Type II PG 0 2 1 1 

Type II EG 0 0 1 1 

Source: EPA airline detailed questionnaire database (USEPA, 2008b). 

4.2.2.2 Mechanical and Nonchemical Deicing/Anti-Icing 

Mechanical and other nonchemical methods used to deice aircraft include brooms, ropes, 

hot water, infrared heating, and forced air. Brooms and ropes are not the primary method of 

aircraft deicing, especially wet-weather deicing, because they are so time- and labor-intensive, 

but rather are used in combination with chemical deicing. Forced air/hot air systems are used to 

blow or melt snow and ice from aircraft surfaces. Infrared heating deicing systems consist of an 

open hangar-type structure with infrared generators suspended from the ceiling. The infrared 

wavelengths are targeted to heat ice and snow and minimize heating of aircraft components. This 

system reduces the volume of ADF fluid required, but cannot provide anti-icing protection. 

Aircraft may also be stored in a hangar to prevent snow or ice from accumulating if a storm 

event is predicted. The most common mechanical and nonchemical methods of deicing/anti-icing 

used by airline questionnaire respondents are mechanical methods and hangar storage. Table 4-7

and Table 4-8 summarize the use of these methods for deicing/anti-icing aircraft by airlines and 

by FBOs, respectively. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

38 

Table 4-7. Summary of Mechanical and Nonchemical Aircraft Deicing Methods Used by an 

Airline 

Mechanical/Nonchemical 

Method 

Number of Airlines Average Number 

2003/2004 2003/2004 2004/2005 of Airlines 

Mechanical (e.g., brooms, ropes) 22 21 21 21 

Hangar storage 15 16 16 16 

Forced air 9 7 7 8 

Hot water 5 4 4 4 

Infrared heating 1 1 1 1 

Source: EPA airline detailed questionnaire database (USEPA, 2008b). 

Table 4-8. Summary of Mechanical and Nonchemical Aircraft Deicing Methods Used By 

FBOs 

Mechanical/Nonchemical 

Method 

Number of Airlines Average Number 

2003/2004 2003/2004 2004/2005 of Airlines 

Mechanical (e.g., brooms, ropes) 10 10 10 10 

Hangar storage 5 5 5 5 

Forced air 4 5 5 5 

Hot water 3 4 4 4 

Infrared heating 0 0 0 0 

Source: EPA airline detailed questionnaire database (USEPA, 2008b). 

4.2.3 Airport Deicing Stormwater Collection and Control 

Deicing and anti-icing operations are conducted at multiple locations at an airport, and 

the fluids are widely dispersed during and after application via ramp discharge, taxiway 

drippage, and residual on aircraft. Deicing stormwater is contained and collected using 

designated deicing areas, stormwater drainage systems, glycol recovery, storage tanks, 

containment ponds, and plug and pump systems. Typical sources of deicing stormwater are: 

• Terminal gates and aprons/areas; 

• Aircraft deicing pads; 

• Taxiways; 

• Airfield ramps; 

• Runways; 

• Cargo apron areas; 

• Maintenance hangar ramps; 

• Aircraft parking areas; 

• Military bases; and 

• ADF-contaminated snow dumps. 

Table 4-9 summarizes the collection and control methods used by airports. Based on 

responses to the airport questionnaire, an estimated 246 U.S. airports use containment, 

collection, and/or conveyance measures to control the discharge of deicing stormwaters to 

surface waters and/or POTWs. Most of the airports use stormwater drainage systems and 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

39 

containment ponds and basins. See Section 9.0 for detailed discussions of deicing stormwater 

collection and control methods used by the Airport Deicing Category. 

Table 4-9. Summary of Airport Collection, Containment, and Conveyance Methods 

Collection/Containment/Conveyance Method 

Estimated Number 

of Airports 

Percentage of 

Airports 

Stormwater drainage system 211 63 

Containment pond/basin 121 36 

Aboveground/underground tank 57 17 

Glycol collection vehicles/sweepers 54 16 

Other (vegetated swales, snow melters, absorbant) 34 10 

Plug and pump 29 9 

Source: EPA airport questionnaire database (scaled to national estimate) (USEPA, 2008c). 

EPA estimates that approximately half (46 percent) of the U.S. airports with deicing 

operations also operate systems to treat or recover their deicing stormwater. The treatment and 

recovery technologies reported by airports include equalization (46 percent), oil/water separation 

(5 percent), sand or other media filtration (4 percent), membrane separation (1 percent), and 

biological treatment (1 percent). Eight percent of the airports report using other types of 

treatment technologies, including MVR, aeration, and distillation. Section 7 describes these 

technologies in detail. 

4.2.4 Pollution Prevention Practices 

To reduce the quantity of pollutants discharged and the amount of deicing stormwater 

generated, airports implement various pollution prevention practices that control pollution from 

airport deicing chemicals (e.g., glycol), thus minimizing pollutant loads by reducing chemical 

usage. Physical snow removal, specialized employee training, and pretreatment of airfields in 

advance of precipitation are the most common practices used by airports for airfield pollution 

prevention. The national estimate of airports implementing one or more pollution prevention 

practices is 244. Table 4-10 summarizes EPA’s national estimates of the number and percentage 

of airports that used airfield pollution prevention practices. See Section 7.4 for detailed 

descriptions of the pollution prevention practices used by airports. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

40 

Table 4-10. Summary of Airfield Pollution Prevention Practices 

Pollution Prevention Practice 

Estimated Number of 

Airports Using Practice 

Percentage of Airports 

Using Practice 

Specialized employee training 153 46 

Pretreatment of airfield in advance of precipitation 101 30 

Runway ice detection system 95 28 

Enhanced weather forecasting 77 23 

Heated sand 74 22 

Evaluation of application rates of deicing fluids 56 17 

Use of alternative chemicals 40 12 

Use of prewet dry chemical constituents 32 10 

Other 88 26 

Source: EPA airport questionnaire database (scaled to national estimates) (USEPA, 2000c). 

Airlines also implement pollution prevention practices at various airports. These practices 

control pollution from aircraft deicing chemicals and minimize pollutant loads. Specialized 

training, implementation of a pollution prevention policy, and physical snow removal are the 

most common pollution prevention practices used by airlines. Table 4-11 summarizes airline 

pollution prevention practices reported in response to the airline detailed questionnaire. See 

Section 7.4 for detailed descriptions of the pollution prevention practices used by airlines. 

Table 4-11. Summary of Aircraft Pollution Prevention Practices 

Pollution Prevention Practice Number of Airlines Reporting Practice 

Specialized employee training 43 

Instituting pollution prevention policy 43 

Physical removal of snow or freezing precipitation 31 

Overnight pretreatment/storage of aircraft 30 

Custom fluid blending 27 

Enhanced weather forecasting 25 

Evaluation of application rates of deicing fluids 24 

Pretreating aircraft with hot water 9 

Use of alternative chemicals 2 

Other 30 

Source: EPA airline detailed questionnaire database (USEPA, 2008b). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 4 – Overview of the Industry 

41 

4.3 References

USDOT. 2008a. Report to Congress: National Plan of Integrated Airport Systems (NPIAS) 

2009-2013. U.S. Department of Transportation, Federal Aviation Administration. Washington, 

D.C. Available online at 

http://www.faa.gov/airports_airtraffic/airports/planning_capacity/npias/reports/. 

USDOT. 2008b. FAA Regional Offices. U.S. Department of Transportation, Federal Aviation 

Administration. Washington, D.C. Available on line at 

www.faa.gov/about/office_org/headquarters_offices/arp/regional_offices/. 

USEPA. 2000. Preliminary Data Summary: Airport Deicing Operations. U.S. Environmental 

Protection Agency. Washington, D.C. EPA-821-R-00-016. DCN AD00005. Available online at 

http://www.epa.gov/guide/airport. 

USEPA. 2005. Supporting Statement: Survey of Airport Deicing Operations. U.S. Environmental 

Protection Agency/Office of Water. Washington, D.C. DCN AD00447. 

USEPA. 2008a. Airline Screener Deicing Questionnaire Database. U.S. Environmental 

Protection Agency. Washington, D.C. DCN AD00937. 

USEPA. 2008b. Airline Detailed Deicing Questionnaire Database. U.S. Environmental 

Protection Agency. Washington, D.C. DCN AD00938. 

USEPA. 2008c. Airport Deicing Questionnaire Database. U.S. Environmental Protection 

Agency. Washington, D.C. DCN AD00927. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

42 

5. DEICING CHEMICAL USE AND DEICING STORMWATER CHARACTERIZATION

This section summarizes EPA’s estimate of the amount of airfield and aircraft 

deicing/anti-icing chemicals currently in use by U.S. primary commercial airports and provides 

information on deicing stormwater pollutant characteristics to the extent possible. Deicing 

stormwater discharges are “weather-dependent” and they are, by nature, highly variable. In 

addition, deicing chemical disposition after its intended use is not fully understood. These 

chemicals may be lost to evaporation, dispersion, or soil absorption; collected; or released into 

the environment and discharged from the airport, but limited information is currently available 

on each of these disposition methods. This section presents the information EPA has collected on 

the types of pollutants present in deicing stormwater and their ranges of concentrations. 

5.1 Deicing Chemical Usage

As discussed in Section 4, several deicing chemicals are commonly used at U.S. 

commercial airports. These chemicals are used for either airfield or aircraft deicing/anti-icing 

and their usages are described below. 

5.1.1 Airfield Chemical Use 

Pavement deicing/anti-icing removes or prevents frost, snow, or ice from accumulating 

on runways, taxiways, aprons, gates, and ramps. Airports use mechanical and chemical methods 

for this purpose. The more often-used method is mechanical removal, but because ice, sleet, and 

snow may be difficult to remove by mechanical methods alone, many airports also use sand 

and/or chemical deicing agents such as potassium acetate, sodium acetate, sodium formate, 

glycol-based products, or urea. Based on the data collected by EPA in the airport questionnaire, 

the most common airfield deicing chemical currently used by U.S. airports is potassium acetate 

(approximately 63 percent of airfield chemical usage by weight). Section 9, Table 9-6 presents 

the average amount of pavement deicing chemical usage in pounds per year by airport and by 

deicing chemical. 

Table 5-1 lists the total estimated national average airfield chemical usage (based on data 

for the 2002/2003, 2003/2004, and 2004/2005 deicing seasons) for primary commercial airports 

in the United States. 

Table 5-1. U.S. Commercial Airports – National Estimate of Airfield Chemical Usage 

Chemical 

Estimated Total Airport Usage 

(tons/year) 

Percentage of 

Chemical Usage 

Potassium acetate 22,538 63 

Propylene glycol-based fluids 3,883 11 

Airside urea 4,127 12 

Sodium acetate 3,100 9 

Sodium formate 1,117 3 

Ethylene glycol-based fluids 774 2 

Source: EPA Airport Deicing Questionnaire Database (USEPA, 2008a) 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

43 

5.1.2 Aircraft Chemical Use and Purchasing Patterns 

There are four types of ADFs manufactured around the world, referred to by the aviation 

and chemical industries as Types I through IV. Of these, Type I and Type IV are commonly used 

at U.S. commercial airports. Type I ADF is used to defrost and deice aircraft and Type IV ADF 

is used to prevent icing from recurring (anti-icing) after initial deicing with a Type I ADF. ADFs 

contain a primary freezing point depressant (typically PG or EG) and other additives. ADFs 

work by adhering to aircraft surfaces to remove and/or prevent snow and ice accumulation by 

virtue of their depressed freezing points. Airports conduct two types of deicing: dry-weather 

deicing to remove frost and wet-weather deicing and anti-icing during precipitation such as 

snow, sleet (ice pellets), or freezing rain. Airports may also perform dry-weather deicing on 

some types of aircraft whose fuel tanks become super-cooled during high-altitude flight, 

allowingfrost/ice to form on aircraft wings at lower altitudes and after landing. Based on the data 

collected by EPA in the airline detailed questionnaire, the most common ADF is Type I PGbased fluids (approximately 77 percent of ADF usage). In addition, U.S. airports have been 

trending towards using more PG-based fluids and less EG-based fluids. Table 9-3 in Section 9 

presents EPA’s estimates of ADF annual usage by airport based on the airline questionnaire 

responses and the estimation procedure outlined in that section. 

Table 5-2 presents a national estimate of the average aircraft chemical usage by U.S. 

commercial airports by type of fluid. 

Table 5-2. U.S. Commercial Airports – National Estimate of Aircraft Chemical Usage 1

Chemical 

Average Total Airport Usage 

(million gallons/year) 2 Percentage of Chemical Usage 

Type I PG ADF 19.305 77.1 

Type IV PG ADF 2.856 11.4 

Type I EG ADF 2.575 10.3 

Type IV EG ADF 0.306 1.2 

Sources: EPA Detailed Airline Questionnaire (USEPA, 2008b); Airport Deicing Loadings Database (USEPA, 

2008c). 

1 EPA used the ADF purchase information to represent usage, per airline industry recommendations. 

2 Total gallons normalized to 100% PG/EG. 

5.2 Deicing Stormwater Characterization

EPA evaluated data from a variety of sources to better understand the components of 

deicing chemicals and ADFs that collect in deicing stormwater. These data include: 

• Information on the additives included in ADFs; 

• Data collected during sampling of concentrated and diluted ADFs used at the 

Detroit Metropolitan Wayne County (DTW) and Minneapolis/St. Paul 

International (MSP) airports during the 2003/2004 deicing season; 

• Data collected during sampling of deicing stormwater at the Albany International 

(ALB), Pittsburgh International (PIT), Denver International (DEN), and Greater 

Rockford (RFD) airports during the 2004/2005 deicing season; 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

44 

• Current data for airports included in the PCS database; and 

• Deicing stormwater data collected by EPA during the PDS, through site visits, or 

through industry or permit authority submissions. 

Section 6 summarizes the types of pollutants found in deicing stormwater based on these 

sources. 

5.2.1 Airfield Deicing Chemicals and Associated Deicing Stormwater 

Most solid airfield deicing chemical products comprise a freezing point depressant (e.g., 

potassium acetate, sodium acetate) and minimal additives (e.g., corrosion inhibitors). Liquid 

airfield deicing chemical products comprise a freezing point depressant (e.g., potassium acetate, 

PG), water, and minimal additives. The airfield deicing products that include salts (i.e., 

potassium acetate, sodium acetate, and sodium formate) will ionize in water, creating positive 

salt ions (K+, Na+) and BOD load as the acetate or formate ion degrades into carbon dioxide 

(CO2) and water. 

Urea is typically applied to pavement and runway areas in granular form. Urea degrades 

by hydrolysis to CO2 and ammonia, which can be toxic to aquatic organisms even at very low 

concentrations. Once ammonia is formed, it either remains in solution as ammonia or its ionized 

form (NH4

+

), biologically converts to other nitrogen forms (e.g., NO3 or N2), or volatilizes to the 

air. The formation of ammonia is dependent on the pH and temperature of the receiving water. 

The higher the pH and temperature, the more ammonia is formed. Another potentially toxic byproduct of urea degradation is nitrous acid, which reacts with secondary amines to form 

nitrosamines, many of which are known carcinogens. 

EPA has limited data on airfield deicing stormwater alone (i.e., stormwater that does not 

also contain aircraft deicing area stormwater). Most of EPA’s stormwater data include both 

airfield and aircraft deicing components. However, during sampling at DTW, EPA collected 

samples from the airport’s runway and open area ponds (Pond 3 East and Pond 6). These ponds 

are not expected to contain aircraft deicing stormwater because a separate pond collects 

wastewater from the gate and deicing pad areas where the stormwater is expected to contain 

ADF. DTW sometimes uses sand and potassium acetate for runway traction and deicing in 

addition to their usual mechanical snow removal equipment. It does not use urea-based deicers. 

Table 5-3 presents the sampling data from the two airfield/open area runoff ponds. 

5.2.2 Aircraft Deicing Chemicals and Associated Deicing Stormwater 

ADFs primarily comprise a freezing point depressant (typically PG or EG), additives, and 

water. Typical additives are thickening agents, wetting agents, corrosion inhibitors, buffer, and 

dye, which make up 1 to 4 percent of the fluid mass. Type IV fluids have higher concentrations 

of the freezing point depressant and greater viscosity so that the fluid stays on the aircraft until 

take-off. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

45 

Table 5-3. EPA’s Analytical Results for Pond 3E Effluent and Pond 6 Effluent, DTW 

Analyte Unit Pond 3 East Effluent Pond 6 Effluent 

BOD5 mg/L 146 43.0 

Chloride mg/L 855 315 

COD mg/L 273 111 

Nitrate/Nitrite (NO2 + NO3-N) mg/L 0.0400 0.110 

Sulfate mg/L 50.1 51.0 

Total Dissolved Solids (TDS) mg/L 1,790 833 

Total Kjeldahl Nitrogen (TKN) mg/L 1.51 0.990 

TOC mg/L 813 314 

Total Phosphorus mg/L 0.340 0.280 

TSS mg/L 150 149 

Aluminum μg/L 1,660 2,110 

Aluminum, Dissolved μg/L ND (50.0) 64.5 

Barium μg/L 92.3 81.8 

Barium, Dissolved μg/L 77.5 66.5 

Calcium μg/L 96,600 69,400 

Calcium, Dissolved μg/L 91,000 63,500 

Chromium 1 μg/L ND (10.0) ND (10.0) 

Copper 1 μg/L ND (10.0) ND (10.0) 

Iron μg/L 3,630 4,390 

Iron, Dissolved μg/L 407 600 

Magnesium μg/L 20,300 17,400 

Magnesium, Dissolved μg/L 18,200 15,700 

Manganese μg/L 508 411 

Manganese, Dissolved μg/L 462 335 

Molybdenum μg/L ND (10.0) ND (10.0) 

Molybdenum, Dissolved μg/L ND (10.0) ND (10.0) 

Sodium μg/L 547,000 191,000 

Sodium, Dissolved μg/L 522,000 189,000 

Titanium μg/L 26.2 34.8 

Zinc 1 μg/L 41.4 43.8 

Acetone μg/L ND (50.0) ND (50.0) 

PG - 1671 2 mg/L ND (10.0) ND (10.0) 

PG - 8015D 2 mg/L ND (10.0) ND (10.0) 

Source: Final Sampling Episode Report Detroit Metropolitan Wayne County International Airport (DTW) (USEPA, 

2006a). 

1 Pollutant listed by EPA as a priority pollutant. See 40 CFR Part 423, Appendix A. 

2 Number following analyte name refers to analytical method. 1671 is a Clean Water Act method and 8015D is a 

hazardous waste method promulgated under the Resource Conservation and Recovery Act (RCRA). 

ND – Not detected (number in parentheses is reporting limit). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

46 

The actual composition of ADFs varies and information on specific additive compounds 

is usually considered proprietary by ADF manufacturers. EPA believes that typical ADFs most 

likely include the following components: 

ADF Component Composition (%) 

PG or EG 50-88 

Surfactant/wetting agent About 0.5 

Corrosion inhibitor/flame retardant About 0.5 

pH buffer About 0.25 

Dyes <1 

Water Remainder 

Source: Environmental Impact and Benefit Assessment for Proposed Effluent Limitations Guidelines and Standards 

for the Airport Deicing Category (ERG, 2009). 

Despite limited public information, EPA has identified two main classes of additives 

widely used among ADF manufacturers. Alkylphenol/alkylphenol ethoxylates (AP/APEO) are 

nonionic surfactants used to reduce surface tension in aircraft deicers and triethanolamine is used 

as a pH buffer. (ERG, 2009). At the time of proposal of the rule, EPA also identified methylsubstituted benzotriazole (MeBT) as an ADF additive, which was used as a corrosion 

inhibitor/flame retardant. In conversations with ADF manufacturers since proposal, EPA has 

been told that the use of triazole compounds in ADF is being discontinued and that triazole use 

in European ADFs has been phased out. EPA also has information indicating that high molecular 

weight, nonlinear polymers may be used as thickening agents in ADFs (see Aircraft Deicing 

Fluids (ERG, 2007b) and various classes of dyes can be used to color the ADF. The classes of 

dyes identified as potentially used in ADFs include azo, xanthene, triphenyl methane, and 

anthroquinone dyes (see Questions Regarding Pylam Dye Use in ADF (ERG, 2007a). 

Analyses conducted by the USGS at General Mitchell International (MKE) airport in 

Milwaukee, WI, and EPA’s sampling programs have confirmed the presence of glycols, triazole 

compounds, and alkylphenol compounds in deicing stormwater. EPA collected deicing 

stormwater samples at MSP and DTW during the 2004/2005 winter season. At MSP, EPA 

collected samples of deicing stormwater from segregated high concentration and low 

concentration storage tanks. At DTW, Northwest collected its deicing stormwater from a March 

24, 2005 deicing event into a portable “frac” tank, which was then sampled by EPA. Table 5-4

lists the constituents detected in these deicing stormwaters and their concentrations. During the 

2005/2006 deicing season, EPA collected five consecutive days of samples of influent to and 

effluent from deicing stormwater treatment at ALB, PIT, DEN, and RFD. The sampled deicing 

stormwater at these airports, prior to treatment, shows a wide range of constituents and 

constituent concentrations among the airports, as shown in Table 5-5 and Table 5-6. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

47 

Table 5-4. MSP and DTW Grab Sample Data Summary for Collected Deicing Stormwater 

Analyte Unit

MSP 

High 

Concentration 

Storage Tank

MSP 

Low 

Concentration 

Storage Tank

DTW 

Northwest Frac 

Tank 

Classical Pollutants

Ammonia as Nitrogen (NH3-N) mg/L ND (0.05) ND (0.05) 0.790 

BOD5 mg/L 115,000 8,000 140,000 

Chloride mg/L 45.0 27.0 25.0 

COD mg/L 358,000 16,000 332,000 

Hexane Extractable Material (HEM) mg/L 50.0 ND (5.00) 22.0 

Nitrate/Nitrite (NO2 + NO3-N) mg/L 0.0950 <0.0600 0.240 

Silica Gel Treated HEM (SGT-HEM) mg/L 17.0 ND (5.00) ND (6.00) 

Sulfate mg/L 21.2 13.6 20.3 

TDS mg/L 1,370 559 1,440 

TKN mg/L 13.5 5.61 71.1 

TOC mg/L 96,100 5,660 93,100 

Total Phosphorus mg/L 6.49 < 2.10 0.320 

Total Recoverable Phenolics mg/L 0.150 0.0375 <0.007 

TSS mg/L 89.0 19.5 11.5 

Total and Dissolved Metals

Aluminum μg/L 525 508 ND (500) 

Aluminum, Dissolved μg/L ND (500) 136 ND (500) 

Antimony, Dissolved 1 μg/L 201 ND (20.0) ND (200) 

Barium μg/L 114 67.1 52.4 

Barium, Dissolved μg/L 36.4 61.9 46.9 

Calcium μg/L 68,200 35,200 127,000 

Calcium, Dissolved μg/L 59,600 34,500 125,000 

Copper 1 μg/L ND (100) 37.6 ND (100) 

Copper, Dissolved 1 μg/L ND (100) 16.4 ND (100) 

Iron μg/L 11,000 7,470 1,410 

Iron, Dissolved μg/L 4,960 6,030 1,370 

Magnesium μg/L 9,230 4,250 12,900 

Magnesium, Dissolved μg/L 8,490 4,080 13,000 

Manganese μg/L 887 317 433 

Manganese, Dissolved μg/L 756 308 423 

Mercury 1 μg/L ND (40) ND (2) 45.1 

Mercury, Dissolved 1 μg/L ND (40) ND (2) 68.7 

Molybdenum μg/L 19,100 794 15,900 

Molybdenum, Dissolved μg/L 19,000 771 16,000 

Sodium μg/L 48,700 18,700 22,800 

Sodium, Dissolved μg/L 48,100 18,600 19,200 

Tin μg/L 611 32.1 673 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

Table 5-4 (Continued) 

48 

Analyte Unit

MSP 

High 

Concentration 

Storage Tank

MSP 

Low 

Concentration 

Storage Tank

DTW 

Northwest Frac 

Tank 

Tin, Dissolved μg/L 616 32.5 646 

Titanium μg/L ND (100) 13.5 ND (100) 

Zinc 1 μg/L 492 291 119 

Zinc, Dissolved 1 μg/L 444 277 119 

Volatile and Semivolatile Organics

Acetone μg/L 1,440 23,700 3,340 

PG – 1671 2 mg/L — — 192,000 

PG – 8015D 2 mg/L 193,000 8,600 170,000 

Trichloroethene 1 μg/L ND (10) ND (10) 14.5 

Sources: Final Sampling Episode Report Minneapolis/St. Paul International Airport (MSP) (USEPA, 2006b); Final 

Sampling Episode Report Detroit Metropolitan Wayne County International Airport (DTW) (USEPA, 2006a). 1 Pollutant listed by EPA as a priority pollutant. See 40 CFR Part 423, Appendix A. 

2 Number following analyte name refers to analytical method. 1671 is a Clean Water Act method and 8015D is a 

hazardous waste method promulgated under the Resource Conservation and Recovery Act (RCRA). 

< – Average result includes at least one nondetect value. 

ND – Not detected (number in parenthesis is reporting limit). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

49 

Table 5-5. DEN, PIT, and ALB - 5-Day Average Data Summary for Untreated Deicing 

Stormwater 

Analyte Units

DEN Effluent from 

Equalization Feed Tank 

5-day Average

PIT Influent to 

Reverse Osmosis 

(RO) Unit 

5-day Average 

ALB Influent to 

Anaerobic Treatment 

System 

5-day Average

Alkalinity mg/L 706 481 159 

NH3-N) mg/L 0.448 ND (0.05) <0.262 

BOD5 mg/L 149,000 16,600 3,400 

COD mg/L 247,000 28,300 5,350 

Chloride mg/L 120 11.6 90.0 

Hardness mg/L 362 542 248 

HEM mg/L 9.20 ND (6.0) ND (5.0) 

NO3-N + NO2-N) mg/L 0.0266 <0.0204 <0.0284 

Sulfate mg/L 60.0 48.1 26.4 

TDS mg/L NC 1,670 650 

TKN mg/L 6.41 9.04 1.61 

TOC mg/L 89,000 7,720 1,570 

Total Orthophosphate mg/L <1.03 <0.0196 0.115 

Total Phosphorus mg/L <2.76 0.0778 0.946 

Total Recoverable Phenolics mg/L 0.0608 0.0187 ND (0.005) 

TSS mg/L <17.8 <8.40 16.6 

Arsenic μg/L <81.8 12.7 ND (10) 

Barium μg/L <13.2 103 42.5 

Boron μg/L <723 532 ND (100) 

Calcium μg/L 103,000 155,000 48,300 

Copper μg/L 305 ND (10) ND (10) 

Iron μg/L 1,210 5,870 6,270 

Magnesium μg/L 5,360 6,260 9,990 

Manganese μg/L 156 532 736 

Molybdenum μg/L 11,900 ND (10) ND (10) 

Selenium μg/L 172 31.8 <5.38 

Sodium μg/L 254,000 54,300 89,600 

Tin μg/L <258 41.0 ND (30) 

Zinc μg/L <81.1 71.8 48.3 

Acetone μg/L 4,100 10,900 15,400 

Benzoic Acid μg/L 716 ND (50) 278 

Methyl Ethyl Ketone μg/L ND (50) ND (50) <58.5 

Phenol μg/L ND (100) ND (100) 24.5 

EG - 1671 1 mg/L <167 <65.6 ND (10) 

EG - 8015D 1 mg/L <172 <73.6 ND (10) 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

Table 5-5 (Continued) 

50 

Analyte Units

DEN Effluent from 

Equalization Feed Tank 

5-day Average

PIT Influent to 

Reverse Osmosis 

(RO) Unit 

5-day Average 

ALB Influent to 

Anaerobic Treatment 

System 

5-day Average

PG - 1671 1 mg/L 174,000 15,700 2,570 

PG - 8015D 1 mg/L 173,000 15,900 2,630 

Tolyltriazole μg/L 10,100 7,860 325 

Nonylphenol, total μg/L ND (5.0) 22.2 ND (12.0) 

Nonylphenol-1-Ethoxylate μg/L ND (7.4) 130 ND (19.0) 

Nonylphenol-2-Ethoxylate μg/L ND (21.0) 190 ND (53.0) 

Nonylphenol-3-Ethoxylate μg/L 17.8 59.9 3.90 

Nonylphenol-4-Ethoxylate μg/L 16.4 15.4 3.01 

Nonylphenol-5-Ethoxylate μg/L 21.5 213 5.70 

Nonylphenol-6-Ethoxylate μg/L 50.4 403 12.5 

Nonylphenol-7-Ethoxylate μg/L 60.7 619 15.4 

Nonylphenol-8-Ethoxylate μg/L 86.2 841 24.7 

Nonylphenol-9-Ethoxylate μg/L 79.1 942 24.7 

Nonylphenol-10-Ethoxylate μg/L 92.5 1,050 38.1 

Nonylphenol-11-Ethoxylate μg/L 100 1,040 40.4 

Nonylphenol-12-Ethoxylate μg/L 216 833 33.7 

Nonylphenol-13-Ethoxylate μg/L 167 589 25.2 

Nonylphenol-14-Ethoxylate μg/L 116 386 17.8 

Nonylphenol-15-Ethoxylate μg/L 69.9 222 8.80 

Nonylphenol-16-Ethoxylate μg/L 43.4 107 4.69 

Nonylphenol-17-Ethoxylate μg/L 23.3 53.5 2.27 

Nonylphenol-18-Ethoxylate μg/L 12.4 23.3 1.09 

Octylphenol μg/L <8.80 ND (0.01) ND (2.00) 

Octylphenol-2-Ethoxylate μg/L 71.8 ND (0.144) 0.159 

Octylphenol-3-Ethoxylate μg/L 1,460 4.38 2.66 

Octylphenol-4-Ethoxylate μg/L 1,260 ND (2.26) ND (2.26) 

Octylphenol-5-Ethoxylate μg/L 891 ND (2.93) ND (2.93) 

Octylphenol-6-Ethoxylate μg/L 441 ND (2.69) ND (2.69) 

Octylphenol-7-Ethoxylate μg/L 198 ND (2.58) ND (2.58) 

Octylphenol-8-Ethoxylate μg/L 116 ND (1.85) ND (1.85) 

Octylphenol-9-Ethoxylate μg/L 44.6 ND (0.636) ND (0.636) 

Octylphenol-10-Ethoxylate μg/L 22.5 ND (0.636) ND (0.636) 

Octylphenol-11-Ethoxylate μg/L 12.0 ND (0.267) ND (0.267) 

Octylphenol-12-Ethoxylate μg/L 8.08 ND (0.113) ND (0.113) 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

Table 5-5 (Continued) 

51 

Analyte Units

DEN Effluent from 

Equalization Feed Tank 

5-day Average

PIT Influent to 

Reverse Osmosis 

(RO) Unit 

5-day Average 

ALB Influent to 

Anaerobic Treatment 

System 

5-day Average

Total Nonylphenol-3-

Ethoxylate-Nonlyphenol-18- 

μg/L 1,170 7,400 260 

Total Octylphenol-2-EthoxylateOctylphenol-12-Ethoxylate μg/L 4,530 ND (16.0) ND (16.0) 

Sources: Draft Sampling Episode Report Denver International Airport (USEPA, 2006c); Draft Sampling Episode 

Report Pittsburgh International Airport (USEPA, 2006d); Draft Sampling Episode Report Albany International 

Airport (USEPA, 2006e). 

1 Number following analyte name refers to analytical method. 1671 is a Clean Water Act method and 8015D is a 

hazardous waste method promulgated under the Resource Conservation and Recovery Act (RCRA). 

ND – Not detected (number in parentheses is reporting limit). 

NC – Not collected. 

< – Average result includes at least one nondetect value. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

52 

Table 5-6. RFD - 1-Day Data Summary for Untreated Deicing Stormwater 

Analyte Units

Influent to Aerobic Treatment 

System, Spring 

Alkalinity mg/L 1,030 

NH3-N mg/L 59.6 

BOD5 mg/L 603 

COD mg/L 646 

Chloride mg/L 14.0 

Hardness mg/L 112 

NO3-N + NO2-N) mg/L 0.0190 

Sulfate mg/L 5.65 

TDS mg/L 384 

TKN mg/L 82.8 

TOC mg/L 137 

Total Phosphorus mg/L 0.330 

TSS mg/L 85.0 

Barium μg/L 20.3 

Calcium μg/L 6,600 

Iron μg/L 108 

Magnesium μg/L 14,700 

Manganese μg/L 164 

Sodium μg/L 4,790 

Acetone μg/L 86.6 

Methyl Ethyl Ketone μg/L 136 

PG - 8015D 1 mg/L 31.0 

Tolyltriazole μg/L 45.3 

Bisphenol A ng/L ND (12,000) 

N-Nonylphenol-2-Ethoxylate NC 50.0 

N-Nonylphenoxyl-2-Carboxylic Acid NC 41.0 

Octylphenol-9-Ethoxylate μg/L ND (3.18) 

Source: Final Sampling Episode Report Greater Rockford Airport (USEPA, 2006f)

1 Number following analyte name refers to analytical method. 8015D is a hazardous waste method promulgated 

under the Resource Conservation and Recovery Act (RCRA). 

ND – Not detected (number in parentheses is reporting limit). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

53 

5.3 Aircraft and Airfield Deicing Chemical Use and Associated Deicing 

Stormwater at Alaskan Airports

Deicing operations at Alaskan airports may be different than those commonly seen at 

other U.S. airports due to the nature of air travel in Alaska and weather conditions. In Alaska, 

small airports have a relatively high number of commercial aircraft departures (including jet 

aircraft) for the suite of communities they serve due to their remote locations with no access to 

the road system. Yet these airports utilize small amounts of ADF and runway deicers because of 

climate conditions (dry and cold), as well as runway maintenance scheduling. For example, in 

Kotzebue, a town of 3,120 people, there are about 12,000 annual departures (including passenger 

and freight jet planes and prop planes) and the fluid usage is only about 1,000 gallons/winter. 

In addition, long periods of below-freezing temperatures affect the the timing of deicing 

stormwater discharges. Deicing materials are not available for collection during freezing 

temperatures because they are encapsulated within the snow and eventually become runoff 

during the spring thaw. Thus, the stormwater runoff is not linked to the time of the ADF 

application. For example, at locations in arctic Alaska such as Bethel Airport (BET), there is no 

stormwater to collect during the deicing season (October – March) as temperatures rarely, if 

ever, go above freezing. For these airports, collection strategies may be significantly different 

than airports located within the lower 48 states. One current practice reported by Ted Stevens 

Anchorage International Airport (ANC) is gas-and-go cargo operations, which involves antiicing on landing during certain weather conditions. This allows the airport to avoid deicing prior 

to departure. This anti-icing procedure also uses less glycol and allows a quicker turnaround. 

Due to the remote nature of Alaskan airports and aircraft scheduling, runways are 

generally prepped for individual flights each day rather than maintaining continuous operation 

around the clock. Because of this, Alaskan airports rely heavily on mechanical methods for 

runway deicing. When airfield deicing chemical use is necessary, most airports in Alaska use 

potassium acetate or urea. 

5.4 References

Corsi, S.R., et al. 2003. Nonylphenol Ethoxylates and Other Additives in Aircraft Deicers, Antiicers, and Waters Receiving Airport Runoff. (January 1). DCN AD00083. 

ERG. 2007a. Personal communication (telecon) between Mary Willett (ERG) and Bob Reynolds 

(Pylam Dyes). Questions Regarding Pylam Dye Use in ADF. (April 16). DCN AD00686. 

ERG. 2007b. Personal communication (telecon) between Mary Willett (ERG) and Jeffery Carey 

(Noveon). Aircraft Deicing Fluids. (April 16). DCN AD00688. 

USEPA. 2006a. Final Sampling Episode Report Detroit Metropolitan Wayne County 

International Airport (DTW), Episode 6508. U.S. Environmental Protection Agency. 

Washington, D.C. (July 12). DCN AD00620. 

USEPA. 2006b. Final Sampling Episode Report Minneapolis/St. Paul International Airport 

(MSP), Episode 6509. U.S. Environmental Protection Agency. Washington, D.C. (July 12). DCN 

AD00622. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 5 – Deicing Chemical Use and Deicing Stormwater Characterization 

54 

USEPA. 2006c. Final Sampling Episode Report Denver International Airport, Episode 6522.

U.S. Environmental Protection Agency. Washington, D.C. (August 2). DCN AD00840. 

USEPA. 2006d. Final Sampling Episode Report Pittsburgh International Airport, Episode 6528.

U.S. Environmental Protection Agency. Washington, D.C. (November 1). DCN AD00841. 

USEPA. 2006e. Final Sampling Episode Report Albany International Airport, Episode 6523.

U.S. Environmental Protection Agency. Washington, D.C. (July 19). DCN AD00842. 

USEPA. 2006f. Final Sampling Episode Report Greater Rockford Airport, Sampling Episode 

6529 (April 20, 2006) and Sampling Episode 6530 (August 29, 2006, January 18, 2008). U.S. 

Environmental Protection Agency. Washington, D.C. DCN AD00839. 

USEPA. 2008a. Airport Deicing Questionnaire Database. U.S. Environmental Protection 

Agency. Washington, D.C. DCN AD00927. 

USEPA. 2008b. Airline Questionnaire Database. U.S. Environmental Protection Agency. 

Washington, D.C. DCN AD00938. 

USEPA. 2008c. Airport Deicing Loadings Database. U.S. Environmental Protection Agency. 

Washington, D.C. DCN AD00857. 

USEPA. 2009. Environmental Impact and Benefit Assessment for Proposed Effluent Limitation 

Guidelines and Standards for the Airport Deicing Category. (July 1). EPA 821-R-09-005. DCN 

AD01197. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 6 – Pollutants of Concern 

55 

6. POLLUTANTS OF CONCERN

EPA identified pollutants in stormwater associated with deicing activities for potential 

control. Pollutants of concern may include pollutants directly associated with deicing chemicals, 

by-products from deicing activities (e.g., metals), and/or pollutant parameters that are influenced 

by deicing chemicals (e.g., BOD and COD). 

EPA reviewed its deicing stormwater sampling data as well as the information available 

through NPDES permits to identify conventional, nonconventional, and priority pollutants 

present in airport deicing stormwater. This section presents the results of EPA’s evaluation and 

identifies potential pollutants of concern and those chosen for regulation. 

6.1 Identification of Airport Deicing/Anti-icing Stormwater Pollutants

Airport deicing stormwater is generated when airfield deicing chemicals and ADFs mix 

with stormwater (either directly or because of snowmelt). Because deicing stormwater is 

weather-dependent, it is highly variable in nature and pollutant concentrations may vary greatly. 

In addition, other airport-related activities, including aircraft fueling and maintenance activities, 

may contribute pollutants to stormwater that is also contaminated with deicing chemicals. 

Because of the inherent difficulties in characterizing pollutants resulting solely from deicing 

activities, EPA evaluated pollutants detected in deicing stormwater, pollutants present in source 

water, and pollutants that are present in ADFs and airfield deicers prior to use to determine the 

pollutants likely to be present in deicing stormwater. 

EPA considered multiple sources of information to identify potential pollutants of 

concern associated with deicing stormwater including the following: 

• EPA sampling data from the PDS; 

• NPDES permits for airports to determine pollutants that are currently monitored 

or limited at airports; 

• EPA sampling data collected during the 2004/2005 and 2005/2006 deicing 

seasons to identify pollutants present in untreated deicing stormwater; 

• EPA sampling data collected during the 2004/2005 and 2005/2006 deicing 

seasons to determine pollutants present in source water; 

• EPA sampling data collected during the 2004/2005 deicing season, current 

research, and expert sources to determine ADF constituents; and 

• Responses to the airport questionnaire. 

Airport Deicing Operations PDS 

For the PDS, EPA sampled: 

• Type I ADFs; 

• Lagoon stormwater from Albany International Airport; 

• Untreated deicing stormwater from Kansas City International Airport; 

• Untreated deicing stormwater from Bradley International Airport; 

• Untreated deicing stormwater from Greater Rockford Airport; and 

• Stormwater outfalls from Bradley International Airport. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 6 – Pollutants of Concern 

56 

The pollutants detected in one or more of these samples were summarized in Table 8-4 of 

the Preliminary Data Summary: Airport Deicing Operations report (USEPA, 2000) and are 

presented in Table 6-1 of this report. 

NPDES Permits 

EPA reviewed NPDES individual and general stormwater permits for airports that are 

estimated to have significant deicing operations in the United States. The permit review is 

summarized in the Airport Deicing Operations NPDES Permit Review Summary memorandum 

(ERG, 2007a). Table 6-1 lists pollutants that have monitoring and limit requirements in current 

airport NPDES permits. 

Pollutants Present in Untreated Deicing Stormwater 

Under this rulemaking effort, EPA collected samples at the following six airports during 

the 2004/2005 and 2005/2006 deicing seasons: 

• Detroit Metropolitan Wayne County (DTW) airport; 

• Minneapolis/St. Paul International (MSP) airport; 

• Albany International (ALB) airport; 

• Greater Rockford (RFD) airport; 

• Pittsburgh International (PIT) airport; and 

• Denver International (DEN) airport. 

Table 6-1 lists pollutants detected in untreated deicing stormwater from these locations. 

Pollutants Present in Source Water 

Table 6-1 also lists pollutants detected in source water samples at the airports EPA 

sampled at during the 2004/2005 and 2005/2006 deicing seasons. 

Deicing/Anti-Icing Fluid Constituents 

EPA does not have sufficient information on all of the constituents of airfield chemicals 

and ADFs to fully characterize them. However, EPA’s airport questionnaire does identify which 

chemicals and brand-name products are commonly used, which can help to define the pollutants 

expected to be in deicing stormwater. 
57 

Technical Development Document for Effluent Limitation Guidelines and Standards for the Airport Deicing Category Section 6 – Pollutants of Concern 

Table 6-1. Pollutants Under Consideration as Potential Pollutants of Concern 

Analyte

Pollutants 

Identified in 

the PDS 

Sampling 

Pollutants 

Monitored in 

NPDES 

Permits 

Pollutants Identified in 

Raw ADF in Research or 

2004-2006 EPA 

Sampling 

Pollutants Identified in 

Untreated Stormwater 

in 2004-2006 EPA 

Sampling 

Classicals/Conventionals Alkalinity X NH3-N X X X BOD5 X X X X COD X X X Chloride X X Dissolved Oxygen X Hardness X Oil & Grease X 

SGT-HEM X X HEM X X X 

NO3-N + NO2-N X X Sulfate X X TDS X TKN X X TOC X X X Total Orthophosphate X Total Phosphorus X X Total Petroleum Hydrocarbons (TPH) X Total Recoverable Phenolics X X TSS X X Metals Aluminum X X Antimony X X X Arsenic X X X Barium X X Boron X X 
58 

Technical Development Document for Effluent Limitation Guidelines and Standards for the Airport Deicing Category Section 6 – Pollutants of Concern 

Table 6-1 (Continued) 

Analyte

Pollutants 

Identified in 

the PDS 

Sampling 

Pollutants 

Monitored in 

NPDES 

Permits 

Pollutants Identified in 

Raw ADF in Research or 

2004-2006 EPA 

Sampling 

Pollutants Identified in 

Untreated Stormwater 

in 2004-2006 EPA 

Sampling 

Cadmium X Calcium X X X Chromium X X Copper X X X X Iron X X X Lead X X Magnesium X X X Manganese X X Mercury X X Molybdenum X X Potassium X Selenium X X Silver X Sodium X X X Thallium X Tin X X X Titanium X Vanadium X Zinc X X X X Organics Acetone X X Benzene, toluene, ethylbenzene, xylene (BTEX) 

X X 

Benzoic Acid X Bis(2-Ethylhexyl) Phthalate X Di-n-butyl Phthalate X Diethylene Glycol X 
59 

Technical Development Document for Effluent Limitation Guidelines and Standards for the Airport Deicing Category Section 6 – Pollutants of Concern 

Table 6-1 (Continued) 

Analyte

Pollutants 

Identified in 

the PDS 

Sampling 

Pollutants 

Monitored in 

NPDES 

Permits 

Pollutants Identified in 

Raw ADF in Research or 

2004-2006 EPA 

Sampling 

Pollutants Identified in 

Untreated Stormwater 

in 2004-2006 EPA 

Sampling 

N-Dodecane X EG X X X N-Hexadecane X Methyl Ethyl Ketone X Naphthalene X Phenol X X PG X X X X N-Tetradecane X 1,2,4- Trimethylbenzene X Trichloroethene X Tolyltriazole X Benzotriazole 5-Methyl-1H-benzotriazole X Alkylphenols Nonylphenol, total X X Nonylphenol-1-Ethoxylate X X Nonylphenol-2-Ethoxylate X X Nonylphenol-3-Ethoxylate X X Nonylphenol-4-Ethoxylate X X Nonylphenol-5-Ethoxylate X X Nonylphenol-6-Ethoxylate X X Nonylphenol-7-Ethoxylate X X Nonylphenol-8-Ethoxylate X X Nonylphenol-9-Ethoxylate X X Nonylphenol-10-Ethoxylate X X Nonylphenol-11-Ethoxylate X X Nonylphenol-12-Ethoxylate X X 
60 

Technical Development Document for Effluent Limitation Guidelines and Standards for the Airport Deicing Category Section 6 – Pollutants of Concern 

Table 6-1 (Continued) 

Analyte

Pollutants 

Identified in 

the PDS 

Sampling 

Pollutants 

Monitored in 

NPDES 

Permits 

Pollutants Identified in 

Raw ADF in Research or 

2004-2006 EPA 

Sampling 

Pollutants Identified in 

Untreated Stormwater 

in 2004-2006 EPA 

Sampling 

Nonylphenol-13-Ethoxylate X X Nonylphenol-14-Ethoxylate X X Nonylphenol-15-Ethoxylate X X Nonylphenol-16-Ethoxylate X X Nonylphenol-17-Ethoxylate X X Nonylphenol-18-Ethoxylate X X Octylphenol X X Octylphenol-2-Ethoxylate X X Octylphenol-3-Ethoxylate X X Octylphenol-4-Ethoxylate X X Octylphenol-5-Ethoxylate X X Octylphenol-6-Ethoxylate X X Octylphenol-7-Ethoxylate X X Octylphenol-8-Ethoxylate X X Octylphenol-9-Ethoxylate X X Octylphenol-10-Ethoxylate X X Octylphenol-11-Ethoxylate X X Octylphenol-12-Ethoxylate X X Total Nonylphenol-3-EthoxylateNonlyphenol-18-Ethoxylate X X Total Octylphenol-2-EthoxylateOctylphenol-12-Ethoxylate X X 

Note: Octylphenol and nonylphenol should have a higher toxicity than the alkylphenol ethoxylates. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 6 – Pollutants of Concern 

61 

The commonly used airfield deicing and anti-icing chemicals are listed below, along with 

the approximate percentage of total airfield deicing chemical usage they comprise: 

• Potassium acetate (64 percent); 

• Propylene glycol-based fluids (12 percent); 

• Urea (11 percent); 

• Sodium acetate (9 percent); 

• Sodium formate (3 percent); and 

• Ethylene glycol-based fluids (2 percent). 

EPA has two sources of data on the constituents of ADF. First, EPA collected and 

analyzed samples of unused, or “raw,” ADF during the sampling episodes at DTW and MSP. 

Table 6-1 lists the chemical compounds for which EPA analyzed the raw ADF samples. Second, 

EPA reviewed research conducted by USGS to determine potential ADF constituents. Steven 

Corsi of USGS conducts research and sampling on ADF and deicing stormwater at General 

Mitchell International Airport in Milwaukee, WI. He has published several papers presenting his 

research and sampling results and has identified the following pollutants in ADF stormwater and 

snowmelt: 

• BOD5; 

• COD; 

• PG and EG; 

• AP and APEO; and 

• Benzotriazole (BT) and its methylated derivatives (MeBT). 

6.2 Pollutants of Concern Selection Criteria

Having identified pollutants that are likely to be present in airport deicing stormwater, 

EPA then considered which pollutants should be pollutants of concern. EPA considered the 

following criteria in assessing potential pollutants of concern for the airport deicing industry: 

• Whether the pollutant can be directly linked to deicing/anti-icing chemicals; 

• Whether the pollutant is detected in the effluent from a small number of airports 

and is uniquely related to those facilities; or 

• Whether the pollutant can be analyzed using an EPA-approved or other 

established method. 

After considering the criteria listed above, EPA developed a list of those pollutants that 

are considered potential pollutants of concern. 

6.3 Identification of Potential Pollutants of Concern

EPA compared the pollutants detected in deicing stormwater to ADF and airfield deicer 

constituents and determined that many pollutants present in the stormwater are not present in 

ADF or airfield deicers. Stormwater contains pollutants from sources other than ADF and 

airfield deicers; these sources may include, but are not limited to, the following: 

• Source water pollutants (present in the water used at the airport facility); 

• Pollutants from aircraft and vehicle fueling; 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 6 – Pollutants of Concern 

62 

• Pollutants from maintenance-related operations; or 

• Pollutants from roof runoff. 

EPA also considered the other criteria listed in Section 6.2 to assess potential pollutants 

of concern. Below is a summary of EPA’s evaluation of potential pollutants of concern by the 

following analytical categories: classical/conventional parameters, metals, and organic 

pollutants. 

Classical/Conventional Parameters 

The major components of both airfield deicing chemicals and ADFs are organic and 

degrade in the environment after their release. Because of this, COD and BOD5 concentrations 

are generally high in deicing stormwater. Both of these pollutant parameters are also good 

indicators of the amount of acetates, urea, glycols, and formates in deicing stormwater. 

EPA believes that those airports with discharge permits requiring monitoring and control 

of ammonia, TKN, and nitrate/nitrite are likely doing so to monitor discharges of urea. 

Information collected during EPA’s airport site visits seemed to indicate that airports have been 

phasing out the use of urea for airfield deicing. However, EPA’s analysis of urea use from the 

airport questionnaire showed an increase during the 2002/2003 through 2004/2005 deicing 

seasons, with approximately the same number of airports using urea in each of those seasons. 

Several of the classical parameters detected in deicing stormwater are from nondeicing 

stormwater, dilution water, or other airport operations. Based on information on airfield deicers 

and analysis of raw ADF, EPA concludes these pollutants are not present in ADF or airfied 

deicers but are present in deicing stormwater. Pollutants from airport sources aside from 

ADF/airfied deicers include alkalinity, hardness, oil and grease, TDS, and TSS. 

Other classical/conventional parameters (including chloride, TOC, and total phosphorus) 

are found in source water, which is used to dilute ADF/airfield deicers prior to application. 

Therefore, EPA concluded these pollutants are not present in ADF/airfield deicers. 

Finally, while total recoverable phenolics are present in EPA sampling results, the 

phenols in ADF are widely reported as alkylphenols and octylphenols; therefore, EPA chose the 

analyte-specific results and not the bulk parameter as the more appropriate indicator of phenols 

in ADF. 

Metals 

Multiple metals have been detected in samples of airport deicing stormwater. Some of 

these metals were also detected in the ADF samples collected by EPA. Many of these metals are 

not original components of deicing products (e.g., aluminum and seleniun); they are present as 

background concentrations from the stormwater or source water used for ADF dilution or they 

are metals picked up by stormwater runoff from aircraft maintenance/operation areas or building 

roofs. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 6 – Pollutants of Concern 

63 

Nonyl/Octyl-Phenol-Ethoxylates 

EPA sampling data shows the presence of both nonylphenol and octylphenol ethoxylates. 

EPA decided to use the total octylphenol and total nonylphenol ethoxolates as the indicator for 

all ethoxolates. 

Organic Pollutants 

Organic pollutants present in deicing stormwater include PG, EG, triazole compounds, 

alkylphenols, and alkylphenol ethoxylates. Other organics may also be present from the 

breakdown of glycols, urea, acetates, and formates. 

Pollutants of Concern 

Based on this evaluation of available data, EPA identified the following as potential 

pollutants of concern for the Airport Deicing Category: 

• COD; 

• BOD5; 

• EG; 

• PG; 

• Benzotriazole; 

• 5-Methyl-1H-benzotriazole; 

• Nonylphenol, total; 

• Octylphenol, total; 

• Total nonylphenol-3-ethoxylate-nonlyphenol-18-ethoxylate; 

• Total octylphenol-2-ethoxylate-octylphenol-12-ethoxylate; 

• Ammonia as nitrogen; 

• Nitrate/Nitrite; 

• TKN; 

• Aluminum; 

• Antimony; 

• Boron; 

• Cadmium; 

• Chromium; 

• Iron; 

• Lead; 

• Magnesium; 

• Mercury; 

• Molybdenum; 

• Potassium; 

• Selenium; 

• Thallium; 

• Tin; 

• Titanium; 

• Vanadium; 

• Zinc; and 

• Acetone. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 6 – Pollutants of Concern 

64 

6.4 Selection of Regulated Pollutants

Table 6-2 lists the potential pollutants of concern identified in Section 6.3, along with an 

explanation of whether EPA selected the pollutants for regulation. Based on the documented 

environmental impacts from stormwater contaminated with airport deicing materials, EPA 

focused on regulating those pollutants exerting oxygen demand and contributing toxicity to 

receiving water bodies. EPA found that the impacts of slug loads of ADF stormwater on the 

dissolved oxygen of receiving streams, as well as color and odor issues associated with high 

ADF concentrations in stormwater discharge, are well documented. The main component of 

ADF is glycol, which exhibits significant oxygen demand. Research by Corsi (Corsi et al., 2006) 

also identified potential toxicity concerns that may be linked to ADF additives, specifically 

triazoles and alkylphenols. ADF manufacturers have told EPA that the use of triazole compounds 

in ADF is being discontinued and that triazole use in European ADFs has been phased out. 

Alkylphenols and their ethoxylates have also been identified as potential toxic components of 

ADF. EPA’s sampling data have confirmed the presence of these compounds; however, EPA 

believes that insufficient information is currently available to fully characterize the extent to 

which these compounds are present in deicing stormwater and their impact. In addition, there is 

not currently an approved EPA method (in 40 CFR Part 136) for these compounds. 

For stormwater discharges from airfield deicing operations, EPA focused on the 

continued use of urea. Urea breaks down into ammonia, and the resulting ammonia toxicity in 

receiving streams has helped to discourage urea use as an airfield deicing chemical in the past. 

When inadequately treated, urea-contaminated wastewater also may contribute to nitrogen 

enrichment and eutrophication of receiving waters. Alternative airfield deicing chemicals, 

predominantly comprising a salt ion (potassium or sodium) and either acetate or formate, are 

available that are less toxic than ammonia. 

Based on the known environmental impacts from deicing stormwater discharges, EPA 

has selected COD and ammonia (as N) for regulation. COD is a good indicator parameter to 

monitor the overall oxygen demand resulting from the discharge of glycol-based ADFs and any 

other organic constituents present in the stormwater. Ammonia as N is selected for regulation to 

ensure that airports cease using urea as an airfield deicer, since other less toxic products are 

available. 

EPA evaluated the impacts of the airport deicing collection and treatment scenarios on 

both BOD5 and COD discharges. EPA selected COD for regulation and not BOD5 for the 

following reasons: 

• COD analyses are simple to conduct and can be measured in real time compared 

to a 5-day test for BOD; 

• COD eliminates the need to consider receiving water temperature when 

evaluating water quality concerns; and 

• Toxic ADF additive compounds in deicing stormwater may have a negative and 

variable affect on the acclimation of the active cultures used in BOD analysis, 

making the method less robust than COD analysis for these wastewaters. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 6 – Pollutants of Concern 

65 

Table 6-2. Potential Pollutants of Concern Selected for Regulation 

Potential Pollutant of Concern 

Selected for 

Regulation Explanation of Selection or Nonselection for Final Rule

BOD5 COD as surrogate 

COD X Selected for regulation 

Ethylene glycol COD as surrogate 

Propylene glycol COD as surrogate 

Benzotriazole Limited data available to support selection; potential 

discontinued use 

5-Methyl-1H-benzotriazole Limited data available to support selection; potential 

discontinued use 

Nonylphenol, Total Limited data available to support selection; no current 

EPA-approved method for analysis 

Octylphenol, Total Limited data available to support selection; no current 

EPA-approved method for analysis 

Total nonylphenol-3-ethoxylatenonlyphenol-18-ethoxylate Limited data available to support selection; no current 

EPA-approved method for analysis 

Total octylphenol-2-ethoxylateoctylphenol-12-ethoxylate Limited data available to support selection; no current 

EPA-approved method for analysis 

Ammonia as nitrogen X Selected for regulation to monitor urea use 

Nitrate/Nitrite Ammonia as nitrogen as surrogate for urea use 

TKN Ammonia as nitrogen as surrogate for urea use 

Aluminum Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Antimony Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Boron Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Cadmium Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Chromium Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Iron Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Lead Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Magnesium Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Mercury Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Molybdenum Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Potassium Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Selenium Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 6 – Pollutants of Concern 

Table 6-2 (Continued) 

66 

Potential Pollutant of Concern 

Selected for 

Regulation Explanation of Selection or Nonselection for Final Rule

Thallium Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Tin Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Titanium Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Zinc Limited impact data for metals; insufficient data to support 

ADF as sole source of metal contamination 

Acetone COD as surrogate 

EPA is not regulating metals in the final airport deicing rule. Given the potential for 

background interference from airport operations, EPA does not have sufficient data to support 

metals as a unique pollutant from ADF alone. 

6.5 References 

Corsi, S.R., et al. 2000. “Aircraft and Runway Deicers at General Mitchell International Airport, 

Milwaukee, Wisconsin, USA. Biochemical Oxygen Demand and Dissolved Oxygen in 

Receiving Streams.” (November 22). DCN AD00081. 

Corsi, S.R., et al. 2003. “Nonylphenol Ethoxylates and Other additives in Aircraft Deicers, Antiicers, and Waters Receiving Airport Runoff.” Environmental Science & Technology, 37:4031-

4037. DCN AD00083. 

Corsi, S.R., et al. 2006. “Characterization of Aircraft Deicer and Anti-icer Components and 

Toxicity in Airport Snowbanks and Snowmelt Runoff.” Environmental Science & Technology.

DCN AD00326. 

ERG. 2006. Memorandum from Steve Strackbein and Cortney Itle (ERG) to Brian D’Amico and 

Eric Strassler (U.S. EPA). Airport Deicing Operations SWPPP and Permit Review. (November 

8). DCN AD00859. 

ERG. 2007a. Memorandum from Jason Huckaby (ERG) to Brian D’Amico and Eric Strassler 

(U.S. EPA). Airport Deicing Operations NPDES Permit Review Summary. (April 16). DCN 

AD00611. 

ERG. 2007b. Memorandum from Maureen Kaplan (ERG) to Mary Willett (ERG). Toxic 

Weighting Factors (TWFs) for Nonylphenol, Octylphenol, and Alkyl Phenol Ethoxylate. (March 

30). DCN AD00862. 

USEPA. 2000. Preliminary Data Summary: Airport Deicing Operations. U.S. Environmental 

Protection Agency. Washington, D.C. EPA-821-R-00-016. (August). 

http://www.epa.gov/guide/airport. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 6 – Pollutants of Concern 

67 

USEPA. 2006. Toxic Weighting Factor Development in Support of CWA 304(m) Planning 

Process. U.S. Environmental Protection Agency. Washington, D.C. (June). DCN AD00861. 

USEPA. 2007. Ecotoxicology (“ECOTOX”) Database. U.S. Environmental Protection Agency. 

Washington, D.C. Available online at www.epa.gov/ecotox/. 

USGS. 2004. Data Summary for Monitoring and Assessment of Changes in Water Quality Due 

to Deicer Management Water Years 1997-2004. General Mitchell International Airport and U.S. 

Geological Survey. (September). DCN AD00085. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

68 

7. COLLECTION AND TREATMENT TECHNOLOGIES APPLICABLE TO AIRPORT 

DEICING OPERATIONS

The NPDES permit program, along with the emergence of problems such as fish kills and 

odor reports, have prompted airports and airlines to investigate a wide range of pollution 

prevention and treatment practices. These practices are designed to eliminate or minimize the 

environmental impact of ADF without compromising safety. This section summarizes the 

common techniques used to collect deicing stormwater and the treatment steps implemented 

prior to discharge. This section also discusses pollution prevention practices used by U.S. 

airports and airlines. 

Each method of collection, treatment, or pollution prevention selected by an airport or 

airline often depends on a variety of airport-specific or airline-specific factors, including climate, 

amount of deicing and anti-icing agents applied, number of airlines operating at a particular 

airport, aircraft fleet mix, number of aircraft operations, costs, presence of existing infrastructure, 

availability of land, and effect on aircraft departures. EPA recognizes that some of the practices 

discussed in this section may not be practical or economically feasible for all U.S. airports. 

EPA evaluated whether regulation of airfield deicing stormwater was practical or costeffective. Because airfield deicing stormwater losses tend to occur over large areas and the 

volumes of dilute stormwater may be very high, at this time EPA could not identify an 

“economically achievable” means to regulate airfield deicing stormwater other than to encourage 

a complete transition away from urea use. Therefore, the technologies presented in this section 

are primarily used to collect and treat ADF-contaminated stormwater. 

Section 7.1 discusses deicing stormwater collection, Section 7.2 describes deicing 

stormwater treatment, Section 7.3 discusses glycol recycling, and Section 7.4 presents pollution 

prevention (e.g., product substitution) practices. 

7.1 Deicing Stormwater Collection

The collection of deicing stormwater from aircraft deicing/anti-icing operations helps 

prevent or minimize discharges at stormwater outfalls. Airports currently use a variety of 

collection and conveyance methods, including designated aircraft deicing pads, gate and ramp 

area drainage collection systems, plug and pump systems, and specially designed glycol 

collection vehicles (GCVs), each of which is discussed in Section 7.1.1. Individual airports often 

rely on a combination of these collection strategies to effectively collect ADF-contaminated 

stormwater. 

Section 7.1.2 presents common methods for storing and discharging deicing stormwater, 

including detention ponds or constructed wetlands, retention ponds, permanent storage tanks or 

frac tanks, discharge to a POTW, trucking waste off site, or any combination of these methods. 

The following sections describe in detail the various wastewater collection methods used by the 

industry. 

7.1.1 Deicing Stormwater Collection and Conveyance 

This section describes the various wastewater collection and conveyance methods 

commonly used by airports. Airport stormwater collection systems are designed to collect 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

deicing stormwater from several different locations at which deicing operations are performed, 

including aircraft deicing at CDPs, at the gates, or at parking or cargo aprons. Collection systems 

may collect stormwater from airfield deicing locations including ramps, taxiways, and runways. 

Common methods of collecting and conveying deicing stormwater include deicing pad collection 

systems, gate and ramp area drainage collection systems, plug and pump systems, and GCVs. 

Deicing Pads 

A CDP is a facility on an airfield built specifically for aircraft deicing operations. It is 

typically a paved area adjacent to a gate area, taxiway, or runway, and constructed with a 

drainage system separate from the airport's main storm drain system. It is usually constructed of 

concrete with sealed joints to prevent the loss of sprayed ADF through the joints. The pad's 

collection system is typically connected to a stormwater storage facility, from which the spent 

ADF may be sent to an on-site or off-site treatment facility. 

Deicing pads restrict aircraft deicing to a confined area, allowing the deicing stormwater 

to be captured at the point of generation and thereby minimizing the volume of sprayed deicing 

fluid discharged in an uncontrolled manner. Aircraft deicing pads also centralize deicing 

activities, which allows airports to more easily collect high-concentration ADF-contaminated 

stormwater. Transporting ADF-contaminated stormwater off site to wastewater treatment plants 

or POTWs is also more economical when the amount of deicing stormwater is minimized. 

One benefit of deicing departing aircraft on deicing pads instead of at the gates is that it 

frees the gates for use by arriving aircraft. Another benefit is that pads are commonly located 

near the heads of runways, where planes can be deiced just prior to takeoff, potentially reducing 

the amount of Type IV anti-icing fluid necessary due to shorter holdover times and the amount of 

glycols transferred from the deicing pad or released into the air. Figure 7-1 shows an example of 

a CDP with fixed boom sprayers. 

Figure 7-1. Deicing Pad Equipped with Fixed Deicing Booms at Pittsburgh Airport 

69 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

70 

Gate and Ramp Area Drainage Collection Systems 

Other than deicing pads, the most common areas for deicing operations are passenger 

terminal gates and aircraft parking or cargo ramps/aprons. To collect wastewater generated at 

these locations, some airports have installed collection systems or modified existing stormwater 

drainage systems. The typical collection system consists of graded concrete pavement with 

trench or square drains that convey wastewater to a storage facility or discharge point through a 

diversion box. Gate and ramp collection systems generally generate low-concentration ADFcontaminated stormwater because more stormwater is mixed in with the ADF and because there 

are increased fugitive losses due to vehicle traffic around the planes. For some stormwater 

drainage systems, a diversion box allows uncontaminated stormwater to be diverted to 

stormwater outfalls. 

Plug and Pump Systems 

Plug and pump collection systems generally comprise devices and equipment that alter an 

airport’s existing storm drain system to contain and collect ADF-contaminated stormwater to 

prevent ADF-contaminated stormwater from entering the storm drain system. These systems 

include, but are not limited to, temporary blocking devices at storm drain inlets and/or shutoff 

valves in the storm sewer system. Some airports use storm drain inserts or plugs to close the 

drains and allow the ADF-contaminated stormwater to collect within the existing airport 

stormwater drainage system. When aircraft are undergoing deicing/anti-icing, the inserts are 

installed to force contaminated stormwater to pool in drainage piping until it can be vacuumed 

or pumped out. This practice prevents manholes and stormwater piping from overflowing. Once 

deicing/anti-icing activity ends and the contaminated stormwater is removed, the storm drain 

inserts can be removed, or deactivated allowing uncontaminated stormwater to pass through the 

drain. Plug and pump collection systems are applicable to airports that deice at the gate and may 

be utilized to convert ramp areas (e.g., cargo, feeder, taxiways) into deicing areas. One benefit of 

deicing at the gate is that the components of the existing collection system infrastructure (i.e., 

existing storm sewers) can be incorporated into the plug and pump collection system, reducing 

the costs associated with deicing control. 

Minneapolis/St. Paul International (MSP) airport is one example of an airport using a 

plug and pump collection system. At MSP airport, 30 percent of deicing operations takes place in 

the airport’s 16 plug and pump containment areas. During the deicing season, the plug and pump 

areas are fitted with compression plugs in the storm sewers to prevent contaminated or 

potentially contaminated stormwater from being discharged. The stormwater plugs convert the 

stormwater sewer pipes and manholes into individual stormwater retention systems that can each 

retain between 5,000 to 42,000 gallons of stormwater. These individual stormwater retention 

systems are monitored during the day to determine how full they are (to prevent overflow) and to 

determine how to manage the ADF-contaminated stormwater based on its composition and 

strength. Contaminated stormwater is pumped or vacuumed from the sewer pipes and tested to 

determine the glycol concentration. Based on the glycol concentration of the wastewater, it is 

stored in either a low-concentration storage tank or a high-concentration storage tank prior to 

being shipped off site (USEPA, 2008a). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

GCVs 

GCVs are specially designed vehicles that remove stormwater contaminated with deicing 

materials from airport deicing pads and gate locations by vacuuming liquid from pavement 

surfaces. GCVs help prevent ADF losses through evaporation and/or direct discharge and allow 

ADF-contaminated stormwater to be collected for treatment or disposal. Drain covers that bond 

to surfaces to quickly seal off drains are often used in conjunction with GCVs in the area where 

aircraft are deiced to allow the GCVs to collect high-concentration spent deicing fluid. 

Commercial GCVs have two basic designs: truck chassis or trailer mounted. The truck 

chassis designs are adapted from the street sweeper concept, with a vacuum unit, 

vacuum/sweeper head, and storage tank all mounted on a single self-propelled vehicle. 

Typically, a separate engine powers the vacuum system. Trailer-mounted designs have the 

vacuum unit, collection head, and storage tank on a towed platform with power provided by 

either an engine mounted on the trailer chassis or a power take-off from the tow vehicle, 

typically a tractor. Figure 7-2 shows an example of a GCV. GCVs help prevent ADFcontaminated stormwater from reaching unpaved areas where infiltration could occur and from 

contaminating surrounding waterways. 

Once ADF-contaminated wastewater is vacuumed from airport surfaces, it is typically 

transported to an on-site storage facility (either temporary or permanent) where the airport can 

then treat and discharge or ship the waste off site. In addition, some airports with collection and 

conveyance or plug and pump systems will have a designated area where the GCV can discharge 

into the collection system, allowing the existing infrastructure to convey the material to final 

storage. 

Figure 7-2. GCV 

71 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

72 

Plug and Pump with GCV 

Commonly, a plug and pump system is operated in conjunction with GCVs or a tanker 

truck with pumps that collect the deicing stormwater that builds up behind the drainage block 

during the deicing event. Additionally, GCVs may be used outside of the blocked area to collect 

ADF-contaminated stormwater to enhance what can be collected through the plugging operation 

alone. 

7.1.2 Deicing Stormwater Storage 

This section describes the various stormwater storage methods commonly used by 

airports. Airport stormwater storage systems are designed to retain deicing stormwater from 

several different locations around an airport, accommodate highly variable flows and volumes, 

and may retain/store stormwater that contains pollutants from both airfield and aircraft deicers. 

Common methods of stormwater storage at airports include detention ponds, equalization ponds, 

retentions ponds, and storage or frac tanks. 

Detention Ponds/Lagoons and Equalization Ponds 

Detention ponds/lagoons are open-water ponds that collect deicing stormwater from 

runways and other airport property. Detention ponds and lagoons are designed to temporarily 

hold deicing stormwater anywhere from one day to two months and allow solids to settle while 

reducing oxygen demand through surface oxygenation and volatilization prior to discharge to 

receiving waters. Detention ponds and lagoons can be lined or gravel-filled and may contain 

microscopic bacteria that biodegrade deicing and anti-icing materials. Pump stations are 

commonly implemented to pump metered wastewater to discharge or further treatment. 

Detention basins often use aeration to increase dissolved oxygen levels. Lagoons may be 

equipped with a floating cover. 

Equalization ponds are detention ponds designed to thoroughly mix ADF-contaminated 

stormwater so that consistent concentrations of pollutants can be pumped from the pond to 

treatment operations or to other disposal. Equalization ponds may contain moving parts, such as 

mixers, to ensure the liquid in the pond is completely mixed. 

Retention Ponds 

Retention ponds are designed to hold collected deicing stormwater indefinitely. Usually 

the pond is designed to allow overflow to drain to another location (e.g., a second retention pond 

or other overflow structure) when the water level gets above the pond capacity. Retention ponds 

can also be used to treat deicing stormwater as part of a batch process (using chemical addition 

and/or aeration) prior to discharge. With retention ponds, airports can collect ADF-contaminated 

stormwater throughout a deicing season and have the option of trucking it off site for treatment 

or treating it on site in the retention pond. 

Advantages and Disadvantages of Ponds in Treating ADF-Contaminated 

Stormwater 

Ponds require large areas for installation and their wastewater normally requires 

treatment for many months after the end of the annual deicing season before it can be discharged. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

FAA discourages airports from installing new stormwater retention ponds, as they can be a lure 

for birds, which are a safety hazard for aircraft (FAA, 2007). For airports with existing retention 

ponds and adequate storage capacity, aerated pond systems may be able to provide efficient 

treatment. See section 7.2.1 for further discussion of aerated pond systems. Figure 7-3 shows an 

example of an airport pond used for deicing stormwater storage. 

Figure 7-3. Pond for Deicing Stormwater Storage 

Storage Tanks 

Airports that treat ADF-contaminated stormwater often use tanks to store the stormwater 

prior to on-site treatment or transfer off site. These types of tanks can be constructed as 

aboveground tanks or underground tanks. Collecting and storing deicing stormwater in storage 

tanks allows an airport to equalize pollutant concentrations and flow the stormwater at a 

consistent flow rate into an on-site treatment system, which is important to ensuring consistent 

treatment results. Portable storage tanks, called frac tanks, can be placed on the airport property 

(while empty) and provide temporary storage of collected deicing stormwater. These types of 

tanks may also be connected by a hose or pipeline to an alternative area. Figure 7-4 shows an 

example of two frac tanks. 

73 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

Figure 7-4. Frac Tanks 

7.2 Treatment 

This section describes the various means of treating stormwater contaminated with 

deicing chemicals. The technologies described within this section are typically used to control 

ADF-related pollutants; however, stormwater with pollutants from airfield deicing operations 

may also be routed into these systems. 

7.2.1 Biological Treatment 

This section describes the treatment of ADF-contaminated stormwater through biological 

processes. Biological treatment consists of two types of processes, aerobic or anaerobic, and can 

take place on site at an airport or off site at POTWs or other treatment facilities. 

POTW Treatment of ADF-Contaminated Stormwater 

Where practical, airports discharge their deicing stormwater to a POTW for biological 

treatment. POTW systems generally use activated sludge in an aerobic biological treatment 

system and may also incorporate anaerobic digestion of the sludge generated. In aerobic

treatment systems, microorganisms consume the organic matter and convert it to water, carbon 

dioxide, and additional biomass in the presence of oxygen. To maintain the microorganism 

population in the treatment process, POTWs using an activated sludge process will use an 

aerated treatment tank followed by a sludge settling tank. Part of the settled sludge is recycled 

back into the aerated treatment tank and the remainder is removed for further processing or 

disposal. 

Airports may be prevented from discharging ADF-contaminated stormwater to a local 

POTW for one or more or the following reasons: (1) limited hydraulic or loading capacity at the 

POTW, (2) high POTW wastewater treatment and/or conveyance fees, (3) inability of the local 

POTW to handle highly variable pollutant loadings, and/or (4) airport infrastructure constraints. 

74 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

75 

Aerated Ponds 

Aerated ponds used on site at airports are effective for treating low-concentration ADFcontaminated stormwater. These are ponds that are open to the atmosphere, though open-topped 

tank systems may also be used. Aerated ponds are not generally used for high-concentration 

ADF-contaminated stormwater because the ponds do not have sufficient oxygen transfer to 

completely convert the ADF pollutants into water, carbon dioxide, and biomass compared to an 

activated sludge system. Treatment ponds may range in size and are usually operated as a batch 

process. 

Aeration in lagoons and ponds increases the level of dissolved oxygen in the water, 

which is needed to decompose organic matter such as glycols. In addition, oxygen helps to 

oxidize certain elements that are suspended in the water, and oxidation causes some materials to 

become heavier so that they will settle out of the water column quicker. Without proper aeration, 

bacteria cannot decompose the organic matter in a pond quickly or efficiently. Aeration devices 

are used to agitate the lagoon or pond surface, which helps to transfer atmospheric oxygen into 

the wastewater to promote biological treatment processes, vent carbon dioxide and other gaseous 

elements from the water, and increase the amount of wastewater exposed to ambient air, 

allowing other volatile organics to oxygenate and evaporate. 

The Greater Rockford airport is an example of an airport operating an aerated pond 

treatment system for deicing stormwater. Greater Rockford airport collects ADF-contaminated 

stormwater throughout the deicing season into a 16-million-gallon aerated detention pond. Its 

aerobic digestion system consists of the aerated detention pond, a settling pond, a re-circulating 

pump, and a chemical addition building. The biodegradation of glycol is temperature-dependant 

and predominantly occurs during the spring and early summer months when ambient 

temperatures are higher. Airport personnel monitor the process, adding nutrients, antifoaming 

agents, and pH adjustment chemicals as needed. When the BOD5 concentration of the pond has 

been reduced to less than 30 mg/L, airport personnel discharge the treated stormwater from the 

settling pond to Rock River (USEPA, 1999). 

Figure 7-5 shows an aerated pond installation at Portland Airport (Oregon). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

Figure 7-5. Aerated Pond Installation at Portland Airport 

Anaerobic Treatment 

Anaerobic treatment systems can effectively treat ADF-contaminated stormwater with a 

range of glycol concentrations. This type of treatment usually occurs in a closed tank in which 

microscopic bacteria in an oxygen-deficient environment biodegrade deicing and anti-icing 

materials. In anaerobic treatment systems, microorganisms consume the organic matter and 

convert it to methane and carbon dioxide in the absence of oxygen, which creates much less 

sludge than an aerobic system. 

AFB treatment is a demonstrated technology for addressing ADF-contaminated 

stormwater at both the Albany, New York (ALB) and Akron/Canton, Ohio (CAK) airports. 

Additionally, Portland completed construction of an AFB in 2011 and testing is slated to be 

complete in 2012. TF Green Airport (Providence, RI) is designing an AFB system, estimated to 

be operational in 2015. (Rhode Island Airport Corporation, 2011). The AFB treatment system 

uses a vertical, cylindrical tank in which the ADF- contaminated stormwater is pumped upwards 

through a bed of granular activated carbon at a velocity sufficient to fluidize, or suspend, the 

media. A thin film of microorganisms grows and coats each granular activated carbon particle, 

providing a vast surface area for biological growth. The anaerobic microorganisms that develop 

occur naturally in sediment, peat bogs, cattle intestines, and even brewer's yeast. Breakdown 

products from the AFB treatment system include methane, carbon dioxide and new biomass. 

Effluent from the AFB can be discharged to a local POTW or, in most cases, directly to surface 

water. Figure 7-6 presents a diagram showing the major components of a typical AFB treatment 

system (Source: US Department of Defense, 2003). 

Treating wastes using an anaerobic biological system compared to an aerobic system 

offers several advantages. Because it does not require aeration, the anaerobic system requires 

76 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

less energy and produces less than 10 percent of the sludge of an aerobic process. In addition, 

because the biological process is contained in a sealed reactor, odors are eliminated. EPA 

evaluated AFB biological treatment as it represents the best technology currently in use by 

airports to treat deicing stormwater prior to direct discharge. 

Figure 7-6. Typical Anaerobic Fluid Bed Treatment System for Treatment of ADFContaminated Stormwater 

Land Application and Constructed Wetlands 

Low-concentration deicing stormwater may also be treated on site at an airport using 

either land application or discharge through constructed wetlands. Land application involves 

spraying deicing stormwater onto a land surface for infiltration and biological degradation within 

the soil. As an example, Salt Lake City International (SLC) airport uses land application to 

dispose of batch volumes of low-concentration deicing stormwater on a periodic basis. The 

system sprays approximately 300,000 to 400,000 gallons of stormwater over nutrient-enriched 

land using agricultural wheels. The application is sprayed at a rate of about 1 gallon per square 

foot over a two-day period. The sprayed glycol then degrades in the soil over a week to monthlong period (USEPA, 2008b). Because glycol-based ADFs readily degrade in both high clay and 

sandy soil systems, this type of system can be effective for low concentrations and limited 

volumes. Biodegradation occurs in the soil through carbon respiration of soil microbes, which 

consume oxygen and release carbon dioxide. Zurich International Airport, Switzerland, also uses 

a spray irrigation system for ADF treatment. At that airport, a heated sprinkler system applies 

ADF-contaminated stormwater to a 20 ha (49.4 acre) area (Jungo Engineering Ltd, 2005). 

Constructed wetlands are artificial marshes or swamps placed inline with stormwater 

drainage at airports. The wetlands act as biofilters and help remove sediments and pollutants 

such as heavy metals from the wastewater. Physical, chemical, and biological processes combine 

in wetlands to remove contaminants from the wastewater. The discharge from constructed 

wetlands can also be collected and treated if it cannot meet discharge permit limits or it can be 

discharged to a POTW or surface water. 

77 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

78 

7.2.2 Physical Separation 

This section describes physical separation processes that are used to treat ADFcontaminated stormwater. Physical separation consists of four types of processes: filtration, 

MVR, membrane separation, and distillation. The treatment can take place on site at an airport or 

off site at other treatment facilities. 

Filtration 

Primary filtration, which removes solids greater than 10 microns, is commonly the first 

step in glycol treatment systems because it removes suspended solids and prevents subsequent 

processing units from plugging. This technology is typically used in combination with other 

technologies. Popular primary filters used in glycol treatment are made of either polypropylene 

cartridges or bag filters. 

MVR 

MVR is an evaporation method that uses mechanically driven compressors or blowers to 

increase the pressure of the vapor produced. The increase in pressure causes the vapor’s 

temperature to increase, which allows it to heat the liquid being concentrated. Benefits of using 

MVR in glycol treatment include: 

• Low specific operating costs; 

• Low specific energy consumption; 

• Short residence times of the product; and 

• Simplicity of the process. 

EPA conducted a site visit and subsequent sampling episode at Denver International 

(DEN) airport, which operates MVRs in the following manner. MVRs concentrate the deicing 

pad storage tank influent, which ranges from 1 to 12 percent PG, to a final concentration of 50 to 

55 percent glycol. Each MVR has a capacity of 3,250 gallons per day. The effluent from the 

MVRs goes to a storage tank where it is stockpiled prior to being sent to a distillation system 

(USEPA, 2007b). The evaporative process may also generate a condensate, which in most cases 

requires further treatment prior to indirect discharge. Typically, this is managed via an RO 

system, with the concentrated material returned to the treatment process and the RO permeate 

discharged to a POTW. 

Membrane Separation 

Membrane separation is an efficient one- or two-step process that incorporates 

ultrafiltration (UF) and/or RO to increase the ADF concentrations of ADF-contaminated 

stormwater. In an UF/RO process, fluid is filtered at a high temperature (75o C) using an 

ultrafiltration membrane as stage one. Next, the deicing fluid (ultrafiltration filtrate) can be 

dewatered using an RO membrane as stage two. The UF membrane is effective at removing 

contaminants such as turbidity, color, and odor, and RO stage two is used for dewatering and 

glycol separation. The combined UF/RO process produces a final glycol concentration of 

approximately 10 percent from an original concentration ranging between 0.5 and 4 percent. 

Pittsburgh International (PIT) airport uses this type of system. The PIT system first treats ADFcontaminated stormwater through an UF unit to remove suspended solids. At this point, the 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

79 

stormwater is 0.5 to 4 percent PG. The stormwater is next treated through an RO unit. Following 

RO, the stormwater is split into two outputs: 1) concentrate that is approximately 10 percent PG, 

and 2) permeate that has a very low glycol concentration. The concentrated PG is transported off 

site for further processing and the permeate containing small amounts of glycol, CBOD, and 

COD is sent to the POTW for further processing (USEPA, 2006). 

Distillation 

Distillation can effectively treat ADF-contaminated stormwater by separating the water 

from the glycol. A potential drawback of distillation is that it creates a distillate that requires 

further treatment. Depending on whether the distillation system is operated in a batch or 

continuous mode, the majority of the distillate can be discharged to the local POTW without 

further processing. In a batch mode, there is a “mid-cut” water/glycol mixture, which marks the 

transition from water removal and product; this volume is redirected to the process feed. 

However, depending on system design and applicable limits, distillate may be able to be directly 

discharged. Distillation columns may be larger and more expensive than other technologies to 

operate, and because distillation is energy-intensive, it is generally not cost-effective to distill 

waste glycol solutions at low concentrations (less than15 percent). Design variables for this 

technology include temperature, distillation column height, and reflux ratio. This process is 

commonly done in batches to ensure proper distillation and desired results. 

EPA conducted site visits at SLC and DEN airports, both of which operate distillation 

columns. 

• At DEN airport, the distillation system runs 24 hours a day for a three-week cycle 

and processes about 225,000 gallons of PG before the system is halted for 

cleaning and maintenance. The distillate from the distillation column is 

discharged to the airport’s storage ponds. The distillation column bottoms 

compile sludge that is classified as specialized nonhazardous waste. The 98 to 99 

percent PG from the distillation column is pumped to a polisher (USEPA, 2007b). 

• At SLC airport, 40 to 45 percent glycol-concentrated stormwater is passed 

through a finisher (one stage of evaporation) to increase the concentration to 

approximately 70 to 80 percent glycol and then discharged to a storage tank. The 

stored concentrate is sent to a distillation column where it is heated to 250 to 260 

degrees Fahrenheit to produce a final product of 100 percent glycol. Distillate 

from the distillation column is discharged to a storage tank prior to RO treatment 

and indirect discharge. The column bottoms (residual solids) are disposed of at an 

off-site facility landfill (USEPA, 2008b). 

7.3 Recycling

Recycling glycol from ADF-contaminated stormwater decreases the amount of ADFcontaminated stormwater that reaches and potentially impairs surface and ground waters. The 

process to recover glycol from ADF-contaminated stormwater may take several steps and can be 

conducted both on site at the airport and/or off site at a regional treatment facility. The recycle 

and recovery technologies currently in use by U.S. airports include filtration, MVR, membrane 

separation, and distillation (discussed in Section 7.2). On-site recycling typically includes some 

combination of these technologies, configured as an integrated treatment train to meet specific 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

80 

requirements of the airport where it is located. Most commonly, an on-site facility initiates the 

process to increase the glycol concentration to make transport to a regional facility for final 

processing more cost-effective. 

Recovered glycol is generally sold to help recover expenses associated with ADF 

application, collection, and control. On-site recycling was successful and economically viable at 

the airports visited by EPA that collected large enough volumes of high-concentration ADFcontaminated stormwater. However, recovery systems may also be able to handle lower 

concentration ADF stormwaters (with glycol concentrations in the 1-2 percent range), and smalland medium-hub airports may be able to recover and recycle glycol using off-site 

recycle/recovery facilities. Off-site facilities can recycle ADF-contaminated stormwater from 

airports not generating sufficient volumes to warrant on-site recycling and treatment. Glycol 

recycling vendors offer a variety of recycle/recovery related services to accommodate different 

airport sizes and configurations. Services commonly provided by glycol recycle/recovery 

vendors include supplying drain blocks, leasing portable storage tanks, on-call trucking services, 

and tote (fluid container) pickups. Key criteria for determining the appropriate recycle/recovery 

program include the type of ADF being collected, glycol concentration of the stormwater, total 

consumption of ADF per season, and peak ADF volume application rates. Other factors to 

consider are the number of deicing days per season at an airport and future air traffic plans.

7.4 Pollution Prevention and Product Substitution Practices

Pollution prevention practices reduce the generation or discharge of pollutants produced 

during aircraft/airfield deicing operations. Pollution prevention practices implemented 

throughout the aviation industry include infrared deicing, forced-air deicing, product substitution 

practices, and BMPs. 

Infrared Deicing 

Infrared heating involves transmitting energy using electromagnetic waves or rays. 

Infrared energy is invisible and travels at the speed of light in straight lines from the heat source 

(the emitter) to all surfaces and objects (the receivers) without significantly heating the space 

(air) through which it passes. This heating process is much faster than convection or conduction 

heating mechanisms used by conventional deicing, where the deicing fluid spray is cooled by 

ambient air. 

Figure 7-7 shows a picture of the infrared hangar at John F. Kennedy (JFK) airport. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

Figure 7-7. Infrared Hangar at JFK 

Infrared-based aircraft deicing systems offer two advantages over traditional glycol-based 

deicing methods. From an environmental standpoint, they can greatly reduce the amount of 

glycol-based fluids used for aircraft deicing, while from an operational standpoint, they are 

relatively inexpensive to operate, as they use natural gas or propane as fuel. 

Any infrared deicing facility must take into account the physical characteristics of all 

aircraft that will use the system. For example, an infrared system design factors in the maximum 

tail height, the shape of tails, maximum wingspans, and differences in the length and width of the 

fuselage. The site selected for an infrared deicing system must comply with the same FAA 

regulations that apply to glycol-based aircraft deicing facilities, including aircraft separation 

rules, airport traffic control tower line-of-sight criteria, and requirements to not interfere with 

radar signals, navigational aids, and airport lighting. FAA issued a new Advisory Circular in 

2005 specifically for infrared deicing facilities (FAA, 2005). As with traditional aircraft deicing 

facilities, an infrared deicing facility must provide taxiways that allow aircraft to bypass the 

deicing facility. 

While EPA encourages the use of this technology, industry practice has shown that it 

may not be applicable at all airports and it appears to be best used in conjunction with other more 

conventional deicing operations (ERG, 2004; Belcher-Hoppe Associates, Inc., 2004). 

Forced Air Deicing 

Forced air deicing uses large volumes of air at low pressure to remove loose 

accumulations of snow and ice from an aircraft prior to chemical deicing. Aircraft deicing trucks 

or fixed booms equipped with forced air nozzles help reduce the amount of glycol that is used 

during deicing and defrosting operations. In light snow conditions, forced air may completely 

replace the need for deicing fluid. For light frost and light deicing events, fluid-injected forced 

air can be used to reduce the amount of deicing fluid by up to 75 percent. For heavy deicing 

events, a fluid forced air technique is used. This technique requires the ADF application rate 

81 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

82 

sprayed from the boom to be reduced from 60 gallons per minute (gpm) to 40 gpm to achieve a 

25-percent reduction in deicing fluid per aircraft. Forced air deicing can reduce operational 

expenses, environmental impacts, and subsequent environmental monitoring or remediation 

expenses (Icewolf product flyer; IDS, 2006). 

Aircraft Deicing/Anti-Icing Product Substitution Practices 

One solution to the environmental problems associated with glycol-based ADF is 

replacing such fluids with more environmentally friendly products. ADFs need to meet FAA’s 

Aerospace Material Specification (AMS) 1424 for Type I fluids and AMS 1428 standards for 

Type IV fluids. These standards require a specified level of product performance and 

compatibility and any alternative product must meet the same standards. To be economically 

viable, alternative products must also be comparably priced and be at least as effective in 

maintaining air safety as the glycol-based fluids they replace and less harmful to the 

environment. 

EPA is aware of one non-glycol, plant-derived product currently being marketed by 

Cryotech Deicing Technology. A new Type I ADF product called “DF Sustain” uses 1,3-

propanediol rather than PG, and is manufactured by a fermentation process using cornstarch. The 

manufacturer claims performance equal or better than PG- or EG-based deicers. 

Table 7-1 lists other aircraft deicing alternatives that EPA is aware of based on literature 

reviews, industry meetings, and site visits. In addition, the airport and airline industry 

associations as well as U.S. Air Force have conducted and are continuing to conduct research 

into other potential substitutes for PG- and EG-based fluids. 

Table 7-1. ADF Alternatives 

Alternative Comments 

PG ADF usage data indicates a trend towards greater PG use as an alternative to EG 

use. 

Hot Air, Forced Air, and 

Tempered Steam Deicing 

The use of hot air, forced air, or tempered steam when deicing aircraft is an 

alternative to typical deicing fluid application techniques using deicing trucks with 

conventional spray nozzles alone. These alternatives can provide more effective 

deicing than conventional spraying technologies and result in lower ADF usage. 

Infrared Deicing Infrared deicing is an alternative to conventional ADF usage and can greatly reduce 

(though not eliminate) the use of ADFs for deicing and anti-icing. 

Cryotech Bio-PDOTM This bio-based product is currently being marketed as an alternative to 

conventional PG-based Type I fluids. 

Warm Fuel for Wing Deicing This type of deicing is an alternative to defrost deicing with ADF. 

Airfield Deicing Product Substitution Practices 

Environmental problems associated with past airfield deicing products like urea led to the 

development of the alternative airfield deicing chemicals used today. Potassium acetate has 

replaced urea as the primary airfield deicer at many U.S. airports. The U.S. Armed Forces no 

longer purchases airfield deicers that contain urea and instead use potassium acetate, sodium 

acetate, and sodium formate. These airfield deicers are highly effective at low temperatures, 

exert much lower oxygen demand than urea, and offer less environmental impact. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

83 

The aviation industry is currently evaluating the impact of common airfield deicing 

chemicals on the environment, runway infrastructure, and chemical corrosion of aircraft carbon 

brakes. Based on the results of this work, EPA anticipates that alternative airfield deicing 

chemicals will be identified and ultimately incorporated into practice. EPA is aware of one such 

product, Cryotech’s Bio-PDOTM2, which is currently being used as an additive for potassium 

acetate runway deicers. The Cyrotech BX36 runway product performs similarly to its widelyused E36 product, but with reductions in electrical conductivity and potassium content (reducing 

carbon brake issues), and a bio-based material composition of 75 percent, allowing for easy 

degradation. 

BMPs 

BMPs are techniques used to limit the amount of ADF applied or allowed to mingle with 

stormwater. EPA defines a BMP as a "technique, measure or structural control that is used for a 

given set of conditions to manage the quantity and improve the quality of stormwater in the most 

cost-effective manner." This section describes the following aircraft/airfield deicing-related 

BMPs: 

• Application rates and deicing fluid dilution; 

• Airfield prewetting; 

• Ice detection systems; 

• Enhanced weather forecasting; 

• Heated sand; 

• Separation of contaminated snow; 

• Annual employee training; 

• Mechanical deicing and snow removal; 

• Yearly inspections of deicing equipment and infrastructure; and 

• Type IV anti-icing. 

Application Rates and Deicing Fluid Dilution 

Deicing personnel can minimize the amount of deicing fluid used at an airport by varying 

deicing fluid application rates and the ADF dilution mix to best match each deicing event 

condition. Application rates are commonly evaluated every time deicing is required. However, 

ADF is usually premixed to a set 55 percent or 45 percent glycol concentration. Systems that 

allow for ADF dilution adjustment based on the weather conditions can use less. Ice thickness, 

ambient temperatures, and plane size all determine application rates and fluid dilution 

requirements. Small planes with small amounts of frost can require as little as 50 gallons of ADF 

while large planes with thick ice accumulations can take up to 2,000 gallons to deice. 

Application rates controlled by chemical metering systems installed to deicing trucks or booms 

allow the applicator to control the distribution of chemicals and maintain a consistent application 

rate at all times. Using a chemical metering system also allows the operator to change the 

application rate in mid-application based on changing weather conditions. 

 

2

 Mention of Cryotech products should not be construed as an endorsement from EPA. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

84 

Airfield Prewetting 

Airfield prewetting involves applying a dry chemical followed by a light coating of liquid 

deicer to airfield pavement. During icy conditions, a granular deicer is generally used to 

penetrate ice and increase surface area prior to using a liquid deicer (generally PG) to help the 

solid deicer stick to the pavement and prevent dry pellets from blowing off. Responses to EPA’s 

airport questionnaire indicated that prewetting is common and helps lower the cost of materials 

by increasing the rate at which the liquid deicer contacts icy surfaces and by minimizing wind 

losses of solid deicer. Following prewetting, snow and ice are generally removed from airfield 

areas using mechanical equipment (such as plows and brooms). 

Ice Detection Systems 

Ice detection systems include sensors installed on runways and taxiways that transmit 

constant surface and subsurface temperature readings to deicing control personnel. These sensors 

indicate whether there is a potential for ice to form on the paved surfaces. Airports can then use 

the information provided by individual deicer manufacturers to determine whether to apply 

deicing/anti-icing chemicals. 

Enhanced Weather Forecasting 

Many of the larger U.S. airports use enhanced weather forecasting systems to help 

determine when they will require deicing activities. A popular weather forecasting product on the 

market is the Weather Support to Deicing Decision Making (WSDDM) software program. This 

system is a “nowcasting” system that is used to confirm National Weather Service data and 

forecasts. WSDDM provides forecasts, monitors storms and provides real-time storm 

information, and estimates and detects precipitation. WSDDM can provide the following 

services to the user: 

1. Real-time snow gauge data (updated every minute) of the liquid equivalent 

snowfall rate at the airport and two to three sites 10 to 20 kilometers (km) away 

from the airport; 

2. Real-time radar reflectivity from radars depicting current locations of 

precipitation and snow; 

3. Meteorological data at the airport and two to three sites 10 to 20 km away from 

the airport updated every minute and displayed in text and time line form, with 

the time line going back two hours; 

4. Thirty-minute nowcast of radar reflectivity based on a cross-correlation technique 

on the radar reflectivity data updated every six minutes; and 

5. Thirty-minute nowcast of liquid equivalent snowfall rate at the airport and the offsite snow gauge locations by applying a real-time snow gauge-radar reflectivity 

calibration algorithm at each of the snow gauge sites, updated every six minutes. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

85 

WSDDM can improve pollution prevention by pinpointing when deicing operations are 

actually needed, which lowers the amount of ADFs used to keep departing aircraft free of ice and 

snow at takeoff and lowers the amount of anti-icing chemicals used to prevent ice and snow from 

bonding to aircraft and taxiways (ERG, 2005). 

Heated Sand 

Sand trucks can be parked in a heated garage with heat piped to the truck. Heating sand 

trucks accomplishes two things. First, heating the truck prevents the moisture in the sand from 

freezing and clumping, which would prevent the sand from being efficiently disbursed when 

applied. Second, applying heated sand to icy surfaces can melt ice and the sand provides needed 

traction when the surfaces refreeze, which minimize the need to use pavement deicers. 

Separation of Contaminated Snow 

Airports often segregate glycol-contaminated snow (commonly called “pink snow”) and 

haul it to a designated area where the snow melt can be collected. Deicing pads often contain 

designated areas to store contaminated snow so that the snow melt can be commingled with other 

deicing stormwater. 

Annual Employee Training 

Training and experience of personel performing aircraft deicing/anti-icing operations 

affects the efficiency of aircraft deicing/anti-icing. Well-trained and experienced deicing/antiicing personnel improve the efficiency of aircraft deicing/anti-icing operations and minimize the 

volume of ADF used. The training and experience of airport personnel may also affect the 

efficiency of airfield deicing operations. Airport personnel are typically responsible for clearing 

taxiways, gate areas, ramps, aprons, and deicing pads. When these areas are not adequately 

cleared, snow and ice accumulate on the undercarriage and the underside of aircraft during 

taxing and must be removed prior to takeoff. 

Many airports conduct annual operations and maintenance training, with specialized 

winter operations training usually conducted prior to the deicing season. This specialized training 

can include but is not limited to proper use of equipment, application of chemicals, and location 

of snow melt areas. Staff may also be trained in environmental awareness detailing the 

requirements of airport permits and BMPs associated with airport deicing/anti-icing operations. 

Mechanical Deicing and Snow Removal 

The amount of ADF required to deice aircraft can be minimized by mechanically deicing 

the aircraft prior to chemical deicing. Mechanical deicing is generally economical only for small 

aircraft because mechanical deicing of large aircraft is labor-intensive and time consuming. A 

drawback of mechanical deicing is that aircraft (e.g., aircraft antennae and sensors) risk being 

damaged by incorrect mechanical deicing methods. Despite the risk of aircraft damage, many 

airlines use brooms, squeegees, and ropes, among other items, to remove ice and snow from 

aircraft surfaces. These methods are more effective at removing snow rather than ice. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

86 

Snow is commonly mechanically removed on airfield pavement, including passenger 

ramps, gate positions, taxiways, and runways, prior to ADF being applied, to prevent 

contamination of the snow. The following types of equipment are used to remove snow from 

airfield surfaces: self-propelled snow brooms, high speed snow blowers and snow plows, and 

utility trucks or tractors fitted with snow brooms or plows. Physical means are generally used to 

remove snow rather than ice. 

Yearly Inspections of Deicing Equipment and Infrastructure 

Inspections are conducted to ensure that equipment used for deicing operations is 

working properly and to determine where maintenance may be needed. Storage tanks are 

inspected to ensure there are no leaks. ADF application equipment is inspected to determine if 

gauges are working properly and that fluid is not being spilled. Trench or square drains are 

inspected to ensure there is no clogging and that water conveyed through the drain does not 

escape. Other equipment and airport infrastructure may require yearly inspections to make 

certain that deicing chemicals are applied with properly functioning equipment and collected 

with suitable infrastructure. 

Type IV ADF Anti-icing 

Type IV ADF protects aircraft from ice, snow, or slush accumulations on cleaned aircraft 

surfaces. Type IV fluids form a protective film on treated surfaces, protecting against ice 

formation and/or snow accumulation. Pretreating aircraft with Type IV fluid is sometimes used 

when ice is in the forecast and an aircraft is expected to remain on the ground for an extended 

period of time. This type of anti-icing treatment can reduce the amount of deicing fluid needed 

for an aircraft by reducing the amount of ice that forms on the aircraft. 

7.5 References

Becher-Hoppe Associates, Inc. 2004. Airport Facilities - Rhinelander - Oneida County Airport. 

(December 6). DCN AD00097. 

CASQA. 2003. Vegetated Swale. (January 1). California Stormwater Quality Association, Menlo 

Park, CA. DCN AD01137. 

ERG. 2004. Aircraft Deicing using an Infrared System called Ice-Cat. (December 13). DCN 

AD00095. 

ERG. 2005. Memorandum from Steve Strackbein (ERG) to Project File: Summary of Weather 

Support to Deicing Decision Making (WSDDM). A Winter Weather Nowcasting System. (January 

3). DCN AD00185. 

ERG. 2007. Memorandum from Juliana Stroup and Mary Willett (ERG) to Brian D’Amico (U.S. 

EPA). Aircraft Deicing Stormwater Control Technologies and Their Removal Efficiencies. 

(December 17). DCN AD00855. 

FAA. 2005. Federal Aviation Administration Advisory Circular 120-89. “Ground De-Icing using 

Infrared Energy. (December 13). DCN AD01139. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 7 – Collection and Treatment Technologies Applicable to Airport Deicing Operations 

87 

FAA. 2007. Federal Aviation Administration Advisory Circular No. 150/5200-33B. “Hazardous 

Wildlife Attractants on or Near Airports.” (August 28). DCN AD01138. 

Icewolf. The Evolution of Aircraft Deicing Systems, Icewolf, Product Flyer. DCN AD00096. 

IDS. 2006. Deicing the IDS Way, Product Flyer. (January 4). DCN D00077. 

Jungo Engineering Ltd. 2005. Disposal of De-icing Effluent by Irrigation. (June 6-8). DCN 

AD01200. 

Rhode Island Airport Corporation. 2011. RIDEM and RIAC Reach Agreement. (December 21). 

www.dem.ri.gov/programs/benviron/water/permits/ripdes/pdfs/riacprelim.pdf. DCN AD01286. 

US Department of Defense. 2003. ESTCP, Mineralization of TNT, RDX, and By-Products in an 

Anaerobic Granular Activated Carbon Fluidized Bed Reactor, (April). DCN AD00898. 

USEPA. 1999. Final Engineering Site Visit Report for Greater Rockford International Airport. 

U.S. Environmental Protection Agency. Washington, D.C. DCN T10402. 

USEPA. 2006. Final Engineering Site Visit Report for Pittsburgh International Airport. U.S. 

Environmental Protection Agency. Washington, D.C. (November 1). DCN AD00774. 

USEPA. 2007a. Final Engineering Site Visit Report for Seattle - Tacoma International Airport.

U.S. Environmental Protection Agency. Washington, D.C. (July 1). DCN AD00778. 

USEPA. 2007b. Final Engineering Site Visit Report for Denver International Airport. U.S. 

Environmental Protection Agency. Washington, D.C. (November 4). DCN AD00779. 

USEPA. 2008a. Final Engineering Site Visit Report for Minneapolis-St. Paul International 

Airport. U.S. Environmental Protection Agency. Washington, D.C. (January 24). DCN 

AD00793. 

USEPA. 2008b. Final Engineering Site Visit Report for Salt Lake City International Airport. 

U.S. Environmental Protection Agency. Washington, D.C. (January 24). DCN AD00792. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 8 – Performance of Control and Treatment Scenarios 

88 

8. PERFORMANCE OF CONTROL AND TREATMENT SCENARIOS

EPA evaluated the performance of the selected control and treatment scenarios based on 

their ability to collect and treat ADF-contaminated stormwater and/or their ability to reduce 

pollutant loadings. EPA used airport-specific estimates of Type I and IV ADF to calculate the 

volumes of applied and available ADF at each of these airports (ERG, 2011a). EPA then 

evaluated the collection ranges of both the data collected by EPA and the data available in the 

Transportation Research Board (TRB) manual (TRB Airport Cooperative Research Program, 

2009), combined with best engineering judgment to estimate the collection efficiency of each of 

the technologies below. 

8.1 Deicing Pad Collection

EPA reviewed data on the performance of centralized deicing pads from a number of 

larger airports across the United States and Europe including DEN, DAY, PHL, CVG, DTW, 

PIT, and Oslo. These airports reported a collection range from 42 to 90 percent of their spent 

and/or applied ADF. 

Additionally, the TRB Airport Cooperative Research Program Report No. 14, Deicing 

Planning Guidelines and Practices for Stormwater Management Systems, detailed airport 

collection efficiencies ranging from 44 to 86 percent of applied glycol (TRB Airport Cooperative 

Research Program, 2009). 

EPA reviewed the airport-specific ADF usage data and determined that the collection of 

42 to 90 percent of spent and/or applied ADF is equivalent to 61 to 90 percent of available ADF 

(ERG, 2011b). At proposal of this rule, EPA estimated the collection efficiency of deicing pads 

to be 60 percent. Based on the Agency’s new analysis, this estimate represents the lower range of 

collection efficiency. As a result, EPA estimates deicing pads will collect at least 60 percent of 

the available ADF. 

8.2 Plug and Pump Collection with GCV

EPA reviewed performance data from General Mitchell International (MKE) airport 

because its collection system matches the plug and pump with GCV collection system EPA 

costed for this rule. MKE reported a collection range between 22.5 and 33 percent of applied 

ADF. 

Additionally, the TRB Airport Cooperative Research Program Report No. 14 reported 

collection efficiencies between 20 and 35 percent of applied ADF for plug and pump systems 

(TRB Airport Cooperative Research Program, 2009). 

At proposal, EPA estimated a plug and pump with GCV collection system would collect 

40 percent of available ADF. When adjusted for rounding, the mean of the data above is 

approximately 40 percent. As such, EPA has determined that a well-operated plug and pump 

system (in conjunction with GCVs) should be able to collect 40 percent of the available ADF. 

DCN AD01270 contains further details on these calculations. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 8 – Performance of Control and Treatment Scenarios 

89 

8.3 GCV Collection 

EPA did not identify nor did commenters provide collection efficiency data on GCVs 

alone. Gerald R. Ford International airport, which uses two tow-behind glycol collection units in 

conjunction with catch basin inserts to collect aircraft deicing contaminated stormwater around 

the terminal gates and apron, reported collecting 29 percent of all applied glycol during the 

2005/2006 deicing season. Mass balance data on glycol usage and collection at Theodore Francis 

Green State airport between 2002 and 2006 indicate that its GCV-based system annually collects 

between 26 and 48 percent of all applied glycol. Overall, collection efficiencies of applied glycol 

from these airports ranged from 26 to 48 percent, although these systems also used some 

combination of catch basin inserts, plug and pump technology, and/or apron systems. 

EPA’s data points are similar to those summarized in the TRB Airport Cooperative 

Research Program Report No. 14. The report described collection efficiencies between 23 to 48 

percent for glycol collection vehicles (TRB Airport Cooperative Research Program, 2009), 

although these systems, like those EPA referenced, also used some combination of catch basin 

inserts, plug and pump technology, and/or apron systems. 

The ranges presented in the literature provide higher collection efficiencies than those 

associated with a plug and pump system; however, all of these data points include technologies 

that would have higher collection efficiencies than a GCV alone. While EPA is unable to 

document the efficiency of a GCV alone, it stands to reason that the collection efficiency of a 

GCV alone would be less than that of a plug and pump with a GCV. For the purposes of today’s 

regulation, on a national basis, EPA assumes that a GCV is able to achieve approximately half 

the collection of a plug and pump with a GCV, or 20 percent of the available ADF. 

8.4 AFB Treatment Performance

EPA collected data on the effectiveness of AFB treatment systems through literature 

review, its own sampling efforts, and industry-supplied data. These systems have demonstrated 

effective treatment for targeted pollutants, including COD, BOD5, and glycol. Based on EPA’s 

sampling data from Albany International airport, COD was reduced by greater than 97 percent, 

BOD5 was reduced by greater than 98 percent, and glycol was reduced by greater than 99 percent 

(ERG, 2007). 

Influent COD concentrations that can be efficiently treated by an AFB system range from 

approximately 2,000 to 128,000 mg/L and an AFB system can manage brief excursions outside 

of this range. (See Airport Council International – North America comments on EPA’s Proposed 

Rule for Effluent Guidelines for the Airport Deicing Category). EPA selected AFB as the best 

technology for on-site treatment of ADF-contaminated stormwater because of the technology’s 

superior ability to destroy the pollutants of concern and to handle a range of influent 

concentrations. An evaluation of AFB treatment for other industrial wastewaters that have high 

COD content, such as distillery, textile, dairy, and brewery wastewaters, shows COD removals in 

the 50 to 98 percent range (ERG, 2010). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 8 – Performance of Control and Treatment Scenarios 

90 

8.5 References

ERG. 2007. Memorandum from Juliana Stroup and Mary Willett (ERG) to Brian D’Amico (U.S. 

EPA). Aircraft Deicing Stormwater Control Technologies and Their Removal Efficiencies. 

(December 17). DCN AD00855. 

ERG. 2010. Memorandum from Cortney Itle (ERG) to Brian D’Amico (U.S. EPA). Summary of 

Anaerobic Fluidized Bed Applications. (August 31). DCN AD01262. 

ERG. 2011a. Memorandum from Cortney Itle and Mary Willett (ERG) to Brian D’Amico (U.S. 

EPA). ADF Collection and Control Efficiency Review. (June 15). DCN AD01270. 

ERG.2011b. Memorandum from Steve Strackbein and Mary Willett (ERG) to Brian D’Amico 

(U.S. EPA). Centralized Deicing Pad ADF Collection Efficiency. (July 12). AD01271. 

TRB Airport Cooperative Research Program. 2009. Deicing Planning Guidelines and Practices 

for Stormwater Management Systems ACRP Report No. 14. DCN AD01191. 

Williams, M. 2006. Baltimore-Washington International Airport Deicing Mass Balance. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

91 

9. POLLUTANT LOADINGS AND POLLUTANT LOAD REDUCTION ESTIMATES

Pollutant loadings from airport deicing operations are highly variable and airportspecific. Because the use of deicing and anti-icing chemicals is weather-dependent, the pollutant 

loadings at each airport vary from year to year based on weather conditions and also based on 

each airport’s climate. In addition, the amount of applied chemical that is discharged to surface 

water depends on the existing stormwater separation, collection, and/or containment system 

present at each airport. 

Due to the variations of the pollutant discharges, EPA determined that it would not be 

appropriate to develop baseline pollutant loadings using end-of-pipe monitoring data. Monitoring 

data on an airport’s deicing stormwater outfall(s) provides only a “snap shot” of a single point in 

time, during a monthly monitoring event or, in some cases, a single storm event. In addition, 

these data are available only for a select number of airports and are airport-specific. Although 

these data provide information on the types of pollutants present in airport deicing stormwater 

and the range of concentrations that may reach outfall points, there is insufficient basis for 

extrapolating or transferring the data across large time frames (e.g., an entire winter season) or to 

other airports. 

Therefore, EPA developed a pollutant loading estimation methodology for individual 

airports based on the use of ADF and airfield chemicals at the airports surveyed by EPA. The 

methodology takes into account EPA’s existing data sources and provides a better estimate of the 

loadings than those based on sporadic monitoring data alone. The Agency used a model-site 

approach to estimate loads for the Airport Deicing Category. A model airport is an operating 

airport whose deicing chemical usage and unit operation and treatment information were used as 

parameters for the loadings model. EPA selected an airport-by-airport approach to estimate 

baseline loadings and loading removals from the model airports, as opposed to a more 

generalized approach, to better characterize the current control and treatment systems in place for 

ADF-contaminated stormwater and to account for current site conditions and airport operations. 

This section discusses the data sources available to EPA to support its pollutant loadings 

and loading reduction estimates (Section 9.1), provides an overview of EPA’s pollutant loading 

methodology (Section 9.2), and describes the calculation steps that compose EPA’s loading 

methodology (Sections 9.3 through 9.6). Section 9.7 summarizes EPA’s approach for estimating 

loading reductions associated with the discontinued use of urea as an airfield deicing chemical. 

9.1 Data Sources

EPA considered the following available data when developing the pollutant loadings 

estimation methodology for airport deicing operations (see Section 3 for more information about 

the data sources): 

• Pavement deicing chemical usage information for the 2002/2003, 2003/2004, and 

2004/2005 deicing seasons, as reported by airport personnel in the airport 

questionnaire; 

• ADF purchase information for the 2002/2003, 2003/2004, and 2004/2005 deicing 

seasons, as reported by airline personnel in the airline detailed questionnaire; 

• Standard airport information available from the FAA, including the number of 

operations and departures by airport; 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

92 

• Weather information for each airport from the National Oceanic and Atmospheric 

Administration (NOAA), including temperature, freezing precipitation, and 

snowfall data; 

• Existing airport stormwater collection and containment systems, as reported by 

airport personnel in the airport questionnaire or during EPA site visits; 

• Standard chemical information about ADF and pavement deicing chemicals, 

including molecular formulas and densities; and 

• Analytical data from EPA sampling episodes of airport deicing operations. 

9.2 Aircraft Deicing Pollutant Loading

This section presents EPA’s methodology for estimating ADF pollutant loads using 

airline questionnaire data on ADF usage and the theoretical oxygen demand associated with 

various deicing fluids. 

9.2.1 Estimate the Amount of Applied Deicing Chemical 

EPA requested the purchase amount, concentration, and brand name in the airline 

detailed questionnaire for the 2002/2003, 2003/2004, and 2004/2005 deicing seasons for the 

following ADF chemicals: 

• EG Type I; 

• EG Type II; 

• EG Type IV; 

• PG Type I; 

• PG Type II; 

• PG Type III; 

• PG Type IV; and 

• Isopropyl Alcohol-Based Fluid. 

Questionnaire responses provided sufficient data to estimate ADF usage at 56 model 

airports. In some cases, data were not available for every airline operating at a model airport. In 

these instances, EPA extrapolated the amount of ADF used at the reporting airlines to estimate 

the total amount of ADF used by the entire airport, based on the number of airport operations 

(departures) at the reporting airlines and the total amount of airport operations. Table 9-1

presents the ADF estimates based on airline questionnaire responses. No airports reported 

purchasing EG Type II, EG Type III, PG Type II, PG Type III, or isopropyl alcohol-based fluid. 

In addition to the ADF data reported in the airline detailed questionnaire, 10 airports 

reported their estimates of total annual ADF usage to EPA in the comment section of the airport 

questionnaire (see Table 9-2). These ADF data were combined with the ADF data reported in the 

airline detailed questionnaires, resulting in 66 airports with total PG/EG (gallons) usage 

estimates. EPA used the airport’s estimate of ADF usage from the airport questionnaires because 

those data came from a certified questionnaire response. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

93 

Table 9-1. ADF Estimates Based on Airline Detailed Questionnaire Responses 

Airport 

ID Airport Name 

Estimated 

PG/EG Use

(GPY) 

PG 

Type I 

(%) 

PG 

Type IV 

(%) 

EG 

Type 1 

(%) 

EG 

Type IV 

(%) 

1003 Ketchikan International 18,182 0 0 100 0 

1006 Chicago O'Hare International 1,516,626 80 20 0 0 

1010 Fairbanks International 83,335 0 0 100 0 

1011 Lambert - St Louis International 325,122 23 1 70 6 

1012 Ted Stevens Anchorage International 420,735 0 0 100 0 

1013 Wiley Post-Will Rogers Mem 3,056 9 0 91 0 

1021 Buffalo Niagara International 281,836 92 9 0 0 

1022 Fort Wayne International 50,412 92 8 0 0 

1024 Indianapolis International 452,155 91 9 0 0 

1026 Dallas/Fort Worth International 166,790 43 12 38 7 

1028 Denver International 1,043,138 87 10 4 0 

1029 La Guardia 485,157 75 22 2 1 

1036 Baltimore - Washington 

International 

323,623 90 10 0 0 

1037 George Bush Intercontinental 

Airport/Houston 

10,242 82 18 0 0 

1043 Ralph Wien Memorial 2,500 27 0 73 0 

1047 Sacramento Mather 1,282 100 0 0 0 

1053 General Edward Lawrence Logan 

International 

995,249 82 17 0 0 

1058 Gerald R Ford International 98,156 86 13 0 0 

1059 Greater Rochester International 229,158 91 9 0 0 

1065 Albany International 125,775 93 7 0 0 

1066 Salt Lake City International 570,540 22 6 52 20 

1069 Cleveland - Hopkins International 582,321 90 10 0 0 

1074 South Bend Regional 29,586 75 25 0 0 

1079 Manchester 177,307 87 13 0 0 

1080 Syracuse Hancock International 186,351 97 3 0 0 

1089 John F Kennedy International 560,031 82 18 0 0 

1095 Chicago Midway International 293,834 88 12 0 0 

1100 Toledo Express 46,449 64 5 29 2 

1103 Juneau International 48,014 0 0 100 0 

1104 Nome 3,047 15 0 85 0 

1105 Spokane International 67,984 92 8 0 0 

1107 Pittsburgh International 943,982 88 12 0 0 

1109 Airborne Airpark 432,416 74 26 0 0 

1110 Aniak 476 100 0 0 0 

1111 Port Columbus International 288,374 92 8 0 0 

1113 Cincinnati/Northern Kentucky 

International 

715,836 24 5 61 11 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-1 (Continued) 

94 

Airport 

ID Airport Name 

Estimated 

PG/EG Use

(GPY) 

PG 

Type I 

(%) 

PG 

Type IV 

(%) 

EG 

Type 1 

(%) 

EG 

Type IV 

(%) 

1117 Cherry Capital 11,524 75 0 0 25 

1118 Bethel 4,897 40 0 60 0 

1123 James M Cox Dayton International 90,580 89 11 0 0 

1124 Des Moines International 79,658 84 14 3 0 

1126 Minneapolis/ St Paul 

International/Wold - Chamberlain 

1,456,537 93 7 0 0 

1128 Charlotte/Douglas International 143,572 81 19 0 0 

1129 Bradley International 427,068 88 12 0 0 

1136 General Mitchell International 152,944 90 9 0 1 

1138 Detroit Metropolitan Wayne County 2,152,292 93 7 0 0 

1139 Philadelphia International 979,983 88 12 0 0 

1140 Memphis International 199,174 88 12 0 0 

1141 Ronald Reagan Washington National 219,533 81 16 3 0 

1142 Washington Dulles International 1,076,083 77 22 1 0 

1145 Newark Liberty International 1,123,057 86 14 0 0 

1148 Kansas City International 203,726 75 8 17 0 

1149 Fort Worth Alliance 1,522 97 3 0 0 

1150 Greater Rockford 146,856 79 21 0 0 

1151 Kalamazoo/Battle Creek 

International 

22,002 84 16 0 0 

1152 Duluth International 68,168 96 4 0 0 

1153 Akron - Canton Regional 60,246 90 10 0 0 

Source: Airport Deicing Operations ADF Usage Database (USEPA, 2008). 

Note: PG/EG gallons represent total usage normalized to 100 percent glycol. Values may not sum to 100 due to 

rounding. 

GPY – Gallons per year. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-2. ADF Data Reported in the Airport Questionnaire 

Airport ID Airport Name PG/EG Usage (GPY) 

1115 Jacksonville International 1,000 

1062 Birmingham International 5,000 

1072 Gillette-Campbell County 880 

1060 Williamson County Regional 150 

1096 Santa Fe Municipal 1,108 

1097 Lovell Field 4,148 

1025 Tupelo Regional 820 

1143 San Francisco International 105 

1001 Montgomery Regional (Dannelly Field) 232 

1019 Ontario International 35 

Source: Airport Deicing Operations ADF Usage Database (USEPA, 2008). 

GPY – Gallons per year. 

Using the airline and airport questionnaire data on ADF purchases, airport departures, 

and climate, EPA correlated the estimate of the amount of ADF used to the climate and size of 

each airport. EPA created an “ADF Factor” to estimate the relative amount of deicing occurring 

at each airport based on the airport’s climate and number of departures. EPA calculated the ADF 

Factor by multiplying the 30-year annual average number of SOFP days by the average number 

of annual departures at each airport during 2004-2006 (USEPA, 2008a). EPA graphed the total 

gallons of PG/EG purchased with the ADF factor and determined the equation of the line. During 

this analysis, EPA noted a difference in the relationship of ADF Factor and ADF usage for 

Alaskan airports compared to other airports. Due to this difference, EPA developed a separate 

graph and equation for Alaskan airports. Figure 9-1 shows the graph for non-Alaskan airports 

and Figure 9-2 presents the graph for Alaskan airports. 

y = 0.3073x

R2 = 0.7622

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

0 2,000,000 4,000,000 6,000,000 8,000,000

ADF Factor (SOFP Days x Average Annual Departures)

PG/EG 

Gallons 

per Year

Figure 9-1. ADF Factor vs. PG/EG Gallons for U.S. Airports (excluding Alaska) 

95 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

y = 0.0632x

R2

 = 0.7031

0

100,000

200,000

300,000

400,000

500,000

0 2,000,000 4,000,000 6,000,000

ADF Factor (SOFP Days x Average Annual Departures)

PG/EG 

Gallons 

Per Year

Figure 9-2. ADF Factor vs. PG/EG Gallons for Alaskan Airports 

EPA used the line equations to estimate the total gallons of ADF used at model airports 

that did not have available ADF data in the airport or airline detailed questionnaires. Based on 

the estimated total gallons of ADF used at an airport, EPA calculated the distribution of different 

types of ADF (PG/EG, Type I/Type IV) based on the average percent distribution of the reported 

ADF amounts. See the Airport Deicing Loadings Calculations memorandum (ERG, 2008b) for 

more detail. Table 9-3 presents the final estimates of ADF usage for airports in the scope of the 

final rule. 

96 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

97 

Table 9-3. ADF Annual Usage Estimates for In-scope Airports 

Airport 

ID Airport Name 

PG Type I 

(gallons) 

PG Type IV

(gallons) 

EG Type I 

(gallons) 

EG Type IV

(gallons) 

1001 Montgomery Regional (Dannelly Field) 166 22 41 3 

1003 Ketchikan International 0 0 18,182 0 

1004 Norfolk International 22,084 2,938 5,451 402 

1006 Chicago O'Hare International 1,213,301 303,325 0 0 

1007 Yeager 35,450 4,715 8,750 646 

1008 Tucson International 1,675 223 413 31 

1010 Fairbanks International 0 0 83,335 0 

1011 Lambert-St Louis International 74,778 3,251 227,586 19,507 

1012 Ted Stevens Anchorage International 0 0 420,735 0 

1014 Albuquerque International Sunport 46,107 6,133 11,380 840 

1015 Gulfport-Biloxi International 1,109 148 274 20 

1017 Austin Straubel International 44,442 5,912 10,969 810 

1018 Piedmont Triad International 49,169 6,540 12,136 896 

1019 Ontario International 25 3 6 0 

1020 Hartsfield - Jackson Atlanta 

International 

259,100 34,465 63,950 4,720 

1021 Buffalo Niagara International 259,289 25,365 0 0 

1022 Fort Wayne International 46,379 4,033 0 0 

1023 Seattle-Tacoma International 112,631 14,982 27,799 2,052 

1024 Indianapolis International 411,461 40,694 0 0 

1026 Dallas/Fort Worth International 71,720 20,015 63,380 11,675 

1028 Denver International 907,530 104,314 41,726 0 

1029 La Guardia 363,868 106,735 9,703 4,852 

1031 Richmond International 42,442 5,646 10,476 773 

1032 Austin-Bergstrom International 17,198 2,288 4,245 313 

1033 Mc Carran International 7,613 1,013 1,879 139 

1034 Metropolitan Oakland International 0 0 0 0 

1035 San Diego International 0 0 0 0 

1036 Baltimore-Washington International 291,261 32,362 0 0 

1037 George Bush Intercontinental 

Airport/Houston 

8,399 1,844 0 0 

1040 Louis Armstrong New Orleans 

International 

0 0 0 0 

1041 Glacier Park International 27,578 3,668 6,807 502 

1043 Ralph Wien Memorial 675 0 1,825 0 

1044 Roanoke Regional/Woodrum Field 23,552 3,133 5,813 429 

1045 Norman Y. Mineta San Jose 

International 

10 0 0 0 

1046 Long Island Mac Arthur 31,135 4,141 7,685 567 

1050 Aspen-Pitkin Co/Sardy Field 10,742 1,429 2,651 196 

1052 Wilmington International 1,556 207 384 28 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-3 (Continued) 

98 

Airport 

ID Airport Name 

PG Type I 

(gallons) 

PG Type IV

(gallons) 

EG Type I 

(gallons) 

EG Type IV

(gallons) 

1053 General Edward Lawrence Logan 

International 

816,104 169,192 0 0 

1054 Jackson Hole 24,413 3,247 6,026 445 

1057 Will Rogers World 35,409 4,710 8,740 645 

1058 Gerald R. Ford International 84,414 12,760 0 0 

1059 Greater Rochester International 208,534 20,624 0 0 

1061 William P Hobby 10,134 1,348 2,501 185 

1062 Birmingham International 3,578 476 883 65 

1063 Evansville Regional 14,412 1,917 3,557 263 

1065 Albany International 116,971 8,804 0 0 

1066 Salt Lake City International 125,519 34,232 296,681 114,108 

1067 Helena Regional 13,147 1,749 3,245 240 

1068 Eppley Airfield 79,386 10,560 19,594 1,446 

1069 Cleveland-Hopkins International 524,089 58,232 0 0 

1070 City of Colorado Springs Municipal 54,230 7,214 13,385 988 

1074 South Bend Regional 22,189 7,396 0 0 

1075 Pensacola Regional 592 79 146 11 

1078 Nashville International 65,479 8,710 16,161 1,193 

1079 Manchester 154,257 23,050 0 0 

1080 Syracuse Hancock International 180,760 5,591 0 0 

1081 Bob Hope 0 0 0 0 

1083 Tampa International 0 0 0 0 

1084 Bismarck Municipal 15,018 1,998 3,707 274 

1086 Palm Beach International 732 97 181 13 

1087 El Paso International 11,608 1,544 2,865 211 

1088 Outagamie County Regional 41,375 5,504 10,212 754 

1089 John F Kennedy International 459,225 100,806 0 0 

1090 Boise Air Terminal/Gowen Fld 51,086 6,795 12,609 931 

1091 Rochester International 24,717 3,288 6,101 450 

1094 Boeing Field/King County International 3,688 491 910 67 

1095 Chicago Midway International 258,574 35,260 0 0 

1097 Lovell Field 2,968 395 733 54 

1099 Sacramento International 0 0 0 0 

1100 Toledo Express 29,728 2,322 13,470 929 

1101 Portland International 80,173 10,664 19,788 1,461 

1102 John Wayne Airport-Orange County 0 0 0 0 

1103 Juneau International 0 0 48,014 0 

1104 Nome 457 0 2,590 0 

1105 Spokane International 62,545 5,439 0 0 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-3 (Continued) 

99 

Airport 

ID Airport Name 

PG Type I 

(gallons) 

PG Type IV

(gallons) 

EG Type I 

(gallons) 

EG Type IV

(gallons) 

1107 Pittsburgh International 830,704 113,278 0 0 

1108 Louisville International-Standiford Field 91,849 12,217 22,670 1,673 

1111 Port Columbus International 265,304 23,070 0 0 

1113 Cincinnati/Northern Kentucky 

International 

171,801 35,792 436,660 78,742 

1114 Stewart International 23,086 3,071 5,698 421 

1115 Jacksonville International 716 95 177 13 

1116 Reno/Tahoe International 53,382 7,101 13,176 973 

1117 Cherry Capital 8,643 0 0 2,881 

1118 Bethel 1,959 0 2,938 0 

1119 Rickenbacker International 7,661 1,019 1,891 140 

1120 Rapid City Regional 18,185 2,419 4,488 331 

1121 Theodore Francis Green State 107,383 14,284 26,504 1,956 

1122 Southwest Florida International 680 90 168 12 

1123 James M Cox Dayton International 80,616 9,964 0 0 

1124 Des Moines International 66,913 11,152 2,390 0 

1126 Minneapolis/St Paul International/WoldChamberlain 1,354,580 101,958 0 0 

1128 Charlotte/Douglas International 116,293 27,279 0 0 

1129 Bradley International 375,820 51,248 0 0 

1130 San Antonio International 9,119 1,213 2,251 166 

1131 Wilkes-Barre/Scranton International 30,426 4,047 7,510 554 

1133 Phoenix Sky Harbor International 0 0 0 0 

1135 Lafayette Regional 1,065 142 263 19 

1136 General Mitchell International 137,650 13,765 0 1,529 

1137 Dallas Love Field 26,622 3,541 6,571 485 

1138 Detroit Metropolitan Wayne County 2,001,632 150,660 0 0 

1139 Philadelphia International 862,385 117,598 0 0 

1140 Memphis International 175,273 23,901 0 0 

1141 Ronald Reagan Washington National 177,822 35,125 6,586 0 

1142 Washington Dulles International 828,584 236,738 10,761 0 

1143 San Francisco International 75 10 19 1 

1144 Central Wisconsin 31,203 4,151 7,702 568 

1145 Newark Liberty International 965,829 157,228 0 0 

1146 Northwest Arkansas Regional 22,013 2,928 5,433 401 

1147 Raleigh-Durham International 73,281 9,748 18,087 1,335 

1148 Kansas City International 152,794 16,298 34,633 0 

Source: Airport Deicing Operations ADF Usage Database (USEPA, 2008). 

Note: Values may not sum to total usage amounts due to rounding. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

100 

9.2.2 Calculate the Amount of Pollutant Load Associated with the Applied ADF 

As aircraft deicing chemicals break down in the environment, they increase COD and 

BOD. EPA calculated the amount of COD and BOD (presented as-5 day BOD, or BOD5) 

associated with the degradation of the applied deicing/anti-icing chemicals. 

EPA considered two approaches to estimate the amount of COD and BOD5 associated 

with deicing chemicals. The first approach involved using laboratory empirical COD and BOD5 

data for deicing chemicals. The second approach involved using standard chemical information 

and stoichiometric equations to estimate COD and BOD5 for each chemical. 

EPA determined it would not be suitable to use empirical data to estimate loadings for 

three main reasons. First, empirical COD and BOD5 data were not readily available for all 

deicing/anti-icing chemicals. Second, the available empirical data were outdated and brandspecific. Finally, chemical formulations vary significantly over time and by brand, so it is 

inappropriate to apply any given set of empirical data to all airports and chemicals. 

EPA selected the second approach, calculating loadings based on standard chemical 

information and stoichiometric equations. The advantage of this methodology over using 

empirical data is that it can be used for all deicing chemicals. In addition, this methodology 

allows the calculations and assumptions used to be clearly presented. EPA checked the validity 

of the COD and BOD5 concentrations for PG and EG calculated using this methodology against 

the available empirical data and found a good match. 

Calculate the Total Mass of Each Pollutant 

First, EPA estimated the total mass of each chemical based on the airline and airport 

questionnaire responses (which specified varying formulations of ADF and deicing products). To 

calculate the total mass of applied chemical, EPA multiplied the reported mass of each chemical 

by the reported percentage of the pollutant in the ADF formulation, by the density of the 

pollutant. 

Determine the Theoretical Oxygen Demand of Each Chemical 

Next, EPA determined the theoretical oxygen demand (ThOD) associated with the 

degradation of each of the deicing chemicals. The ThOD estimate was based on the molecular 

formula of the chemical and the stoichiometric equation of the breakdown of the chemical to the 

end products of carbon dioxide and water. Table 9-4 lists the calculated ThOD for each chemical 

in aircraft deicers. 

Table 9-4. Theoretical Oxygen Demand Calculations for Aircraft Deicing Chemicals 

Deicing Compound 

Molecular 

Formula Stoichiometric Formula 

ThOD (Moles of O2

per Mole of Deicing

Compound) 

PG C3H8O2 C3H8O2 + 4 O2 Æ 3 CO2 + 4 H2O 4.0 

EG C2H6O2 2[C2H6O2] + 5 O2 Æ 4 CO2 + 6 H2O 2.5 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Determine the COD of Each Chemical 

EPA next determined the COD loading associated with the chemical’s degradation. EPA 

assumed that the chemical would completely degrade in the environment over time and therefore 

the calculated ThOD load would be equivalent to the COD load. EPA estimated the COD load 

associated with each reported chemical based on the calculated mass of the chemical purchased, 

the molecular weight of the chemical, the ThOD, and the molecular weight of oxygen, using the 

equation below: 

grams 434

pound

O of moles

O of grams Molecular O Weight chemical of moles

O of moles ThOD

chemical of grams

chemical of moles Molecular Chemical Weight pound

grams 434 (pounds) Load COD (pounds) Chemical

2

2

2

2 ⎟×

⎠

⎞ ⎜

⎝

⎛ ⎟×

⎠

⎞ ⎜

⎝

⎛ ×

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ = × ×

 (9-1) 

Determine the BOD5 of Each Chemical 

EPA calculated the BOD5 loading of ADF based on the estimated COD loading in ADF. 

EPA developed an industry-specific relationship between COD and BOD5 using analytical data 

for untreated deicing stormwater from the EPA sampling episodes at Albany International 

airport, Pittsburgh International airport, and Denver International airport. The average 

COD/BOD5 ratio was 1.67. This relationship was used to calculate the BOD5 associated with the 

degradation of the deicing chemical. See the Airport Deicing Loading Calculations 

memorandum (ERG, 2008b) for more information. 

9.2.3 Estimate the Amount of Baseline Pollutant Load that is Discharged Directly 

The amount of applied chemical that is discharged directly is airport-specific and 

dependent upon the existing stormwater collection/treatment system present at each airport. 

Typically, ADF is applied at a number of specific locations at the airport, including gates, 

deicing pads, and/or aprons. 

In estimating the direct discharge amount of ADF, EPA first estimated the amount of 

applied ADF that would be available for discharge. EPA assumed that 75 percent of applied 

Type I ADF falls onto the pavement at the deicing area and is available for discharge; the 

remaining 25 percent is lost to evaporation, wind, or tire tracking, or adheres to the plane and is 

later sheared off during taxiing and takeoff (Switzenbaum, et al., 1999). EPA assumed that 10 

percent of Type IV ADF falls to the pavement in the deicing area and is available for discharge; 

the remaining 90 percent adheres to the plane. The Agency multiplied the total amount of applied 

ADF by the appropriate percentage available for discharge to determine the amount of ADF that 

is available for discharge. 

Next, EPA determined the percentage of available ADF that would be directly discharged 

at each airport, depending on the airport’s current control and treatment systems (ERG, 2011). 

EPA estimated collection and control percentages of available ADF for each airport based on 

information provided during EPA site visits and in the airport questionnaire. If the airport did not 

provide an ADF collection and control percentage estimate, EPA personnel reviewed the 

airport’s questionnaire responses and the reported collection and control percentage of similar 

systems to determine an estimate for the airport. 

101 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

102 

The COD load associated with each ADF chemical applied at an airport was reduced by 

EPA’s estimate of the airport’s current collection and control percentage to estimate the amount 

of COD directly discharged. These estimates represent the baseline amount of ADF discharged 

to the environment. Table 9-5 in Section 9.2.5 presents EPA’s estimate of the baseline COD load 

(in pounds) directly discharged by each airport. 

9.2.4 Estimate Pollutant Loading Discharges for Each ADF Collection/Control 

Scenario 

Two of EPA’s regulatory options require a specific collection and treatment percentage 

of available ADF. For the final rule, EPA evaluated the following scenarios as discussed in 

Section 11: 

• 20% Collection and Control Scenario: collection and treatment of 20 percent of 

available ADF; and 

• 40% Collection and Control Scenario: collection and treatment of 40 percent of 

available ADF. 

EPA estimated the direct discharge COD load of each collection and control scenario 

accounting for the following two components: 

• The COD load associated with the applied ADF, minus any reductions achieved 

by the collection and control practices implemented; and 

• The COD load that would be discharged from AFB biological treatment of the 

collected treatment. 

EPA estimated the amount of COD load that would be discharged from treatment for 

each airport that had load reductions in a scenario. Using analytical data from its sampling 

episodes, EPA determined that AFB systems remove 97.5 percent of COD. Therefore, EPA 

assumed that 97.5 percent of the COD load going to treatment would be removed and 2.5 percent 

would be discharged. 

9.2.5 Estimate Pollutant Loading Reductions for Each ADF Collection/Control 

Scenario 

After estimating the loads for each scenario, EPA estimated the loading reductions as 

compared to baseline. Table 9-5 lists the ADF COD baseline loads and reductions for each 

control and treatment scenario EPA evaluated for those airports in the scope of the final rule. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

103 

Table 9-5. ADF COD Baseline Loads and Loading Reductions for Each Control and 

Treatment Scenario, by In-Scope Airport 

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Current 

ADF 

Collection 

(%) 

Baseline 

COD Load 

(pounds) 

COD Load 

Reduction for 

20% Collection 

and Control 

Scenario 

(pounds) 

COD Load 

Reduction for 

40% Collection 

and Control 

Scenario 

(pounds) 

1001 Montgomery Regional 

(Dannelly Field) 

6.7013 0 2,214 432 863 

1003 Ketchikan International 1.0000 NA 0 0 0 

1004 Norfolk International 1.0000 20 235,637 0 57,436 

1006 Chicago O'Hare International 1.0000 40 8,204,552 0 0 

1007 Yeager 2.1508 40 283,685 0 0 

1008 Tucson International 2.9997 20 17,873 0 4,357 

1010 Fairbanks International 1.0000 ≥60 299,205 0 0 

1011 Lambert-St Louis International 1.0000 ≥60 1,154,584 0 0 

1012 Ted Stevens Anchorage 

International 

1.0000 40 2,265,902 0 0 

1014 Albuquerque International 

Sunport 

1.0000 20 491,959 0 119,915 

1015 Gulfport-Biloxi International 5.8413 ≥60 0 0 0 

1017 Austin Straubel International 2.3269 40 355,646 0 0 

1018 Piedmont Triad International 1.0000 0 655,787 127,879 255,757 

1019 Ontario International 1.0000 0 334 200 200 

1020 Hartsfield - Jackson Atlanta 

International 

1.0000 ≥60 1,382,287 0 0 

1021 Buffalo Niagara International 1.0000 40 1,718,928 0 0 

1022 Fort Wayne International 1.9682 0 511,705 102,341 204,682 

1023* Seattle-Tacoma International 1.0000 0 1,502,208 292,931 585,861 

1024 Indianapolis International 1.0000 40 2,728,125 0 0 

1026 Dallas/Fort Worth International 1.0000 ≥60 557,682 0 0 

1028 Denver International 1.0000 ≥60 104,244 0 0 

1029 La Guardia 1.0000 0 4,216,728 822,262 1,644,524 

1031 Richmond International 1.0000 40 339,643 0 0 

1032 Austin-Bergstrom International 1.0000 40 137,629 0 0 

1033 Mc Carran International 1.0000 40 60,923 0 0 

1034 Metropolitan Oakland 

International 

1.0000 ≥60 0 0 0 

1035 San Diego International 1.0000 ≥60 0 0 0 

1036 Baltimore-Washington 

International 

1.0000 ≥60 1,289,506 0 0 

1037 George Bush Intercontinental 

Airport/Houston 

1.0000 40 56,571 0 0 

1040 Louis Armstrong New Orleans 

International 

1.0000 ≥60 0 0 0 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-5 (Continued) 

104 

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Current 

ADF 

Collection 

(%) 

Baseline 

COD Load 

(pounds) 

COD Load 

Reduction for 

20% Collection 

and Control 

Scenario 

(pounds) 

COD Load 

Reduction for 

40% Collection 

and Control 

Scenario 

(pounds) 

1041 Glacier Park International 3.1409 0 367,815 71,724 143,448 

1043 Ralph Wien Memorial 1.0000 0 23,743 4,630 9,260 

1044 Roanoke Regional/Woodrum 

Field 

2.1921 0 314,124 61,254 122,508 

1045 Norman Y. Mineta San Jose 

International 

1.0000 10 0 0 0 

1046 Long Island Mac Arthur 1.9985 ≥60 166,102 0 0 

1050 Aspen-Pitkin Co/Sardy Field 4.7500 40 85,963 0 0 

1052 Wilmington International 6.0388 0 20,756 4,047 8,095 

1053 General Edward Lawrence 

Logan International 

1.0000 0 9,147,072 1,783,679 3,567,358 

1054 Jackson Hole 4.3500 ≥60 0 0 0 

1057 Will Rogers World 1.0000 0 472,260 92,091 184,181 

1058 Gerald R. Ford International 1.5862 40 563,544 0 0 

1059 Greater Rochester International 1.0000 50 1,152,208 0 0 

1061 William P Hobby 1.0000 ≥60 0 0 0 

1062 Birmingham International 2.8410 0 47,717 9,305 18,610 

1063 Evansville Regional 5.1042 0 192,217 37,482 74,965 

1065 Albany International 1.0000 ≥60 25,771 0 0 

1066 Salt Lake City International 1.0000 ≥60 1,687,338 0 0 

1067 Helena Regional 4.2000 ≥60 0 0 0 

1068 Eppley Airfield 1.0000 0 1,058,801 206,466 412,933 

1069 Cleveland-Hopkins 

International 

1.0000 40 3,480,467 0 0 

1070 City of Colorado Springs 

Municipal 

1.7414 40 433,971 0 0 

1074 South Bend Regional 2.1417 ≥60 0 0 0 

1075 Pensacola Regional 3.9341 ≥60 0 0 0 

1078 Nashville International 1.0000 ≥60 349,329 0 0 

1079 Manchester 1.0000 0 1,715,962 334,613 669,225 

1080 Syracuse Hancock International 1.0000 ≥60 791,854 0 0 

1081 Bob Hope 1.0000 ≥60 0 0 0 

1083 Tampa International 1.0000 ≥60 0 0 0 

1084 Bismarck Municipal 3.8679 0 200,305 39,059 78,119 

1086 Palm Beach International 1.0000 ≥60 0 0 0 

1087 El Paso International 3.0457 ≥60 0 0 0 

1088 Outagamie County Regional 2.4841 0 551,842 107,609 215,218 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-5 (Continued) 

105 

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Current 

ADF 

Collection 

(%) 

Baseline 

COD Load 

(pounds) 

COD Load 

Reduction for 

20% Collection 

and Control 

Scenario 

(pounds) 

COD Load 

Reduction for 

40% Collection 

and Control 

Scenario 

(pounds) 

1089 John F Kennedy International 1.0000 0 5,155,239 1,005,272 2,010,543 

1090 Boise Air Terminal/Gowen Fld 1.5043 ≥60 272,543 0 0 

1091 Rochester International 3.1749 40 197,799 0 0 

1094 Boeing Field/King County 

International 

5.8985 40 29,510 0 0 

1095 Chicago Midway International 1.0000 ≥60 0 0 0 

1097 Lovell Field 4.9996 0 39,586 23,752 23,752 

1099 Sacramento International 1.0000 20 0 0 0 

1100 Toledo Express 2.0917 20 359,704 0 87,678 

1101 Portland International 1.0000 20 855,437 0 208,513 

1102 John Wayne Airport-Orange 

County 

1.0000 ≥60 0 0 0 

1103 Juneau International 1.0000 0 430,969 84,039 168,078 

1104 Nome 1.0000 0 28,231 5,505 11,010 

1105 Spokane International 1.5192 ≥60 0 0 0 

1107 Pittsburgh International 1.0000 ≥60 3,689,998 0 0 

1108 Louisville InternationalStandiford Field 1.0000 ≥60 490,009 0 0 

1111 Port Columbus International 1.0000 0 2,927,149 570,794 1,141,588 

1113 Cincinnati/Northern Kentucky 

International 

1.0000 ≥60 415,766 0 0 

1114 Stewart International 2.8661 40 184,745 0 0 

1115 Jacksonville International 1.0000 ≥60 0 0 0 

1116 Reno/Tahoe International 1.0000 20 569,580 0 138,835 

1117 Cherry Capital 3.5400 ≥60 0 0 0 

1118 Bethel 1.0000 0 47,733 9,308 18,616 

1119 Rickenbacker International 4.3659 0 102,180 19,925 39,850 

1120 Rapid City Regional 3.1082 0 242,540 47,295 94,591 

1121 Theodore Francis Green State 1.0000 ≥60 572,884 0 0 

1122 Southwest Florida International 1.0000 ≥60 0 0 0 

1123 James M Cox Dayton 

International 

1.0000 ≥60 357,499 0 0 

1124 Des Moines International 1.6211 40 460,483 0 0 

1126 Minneapolis/St Paul 

International/WoldChamberlain 

1.0000 ≥60 5,968,923 0 0 

1128 Charlotte/Douglas International 1.0000 0 1,308,047 255,069 510,138 

1129 Bradley International 1.0000 ≥60 1,669,398 0 0 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-5 (Continued) 

106 

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Current 

ADF 

Collection 

(%) 

Baseline 

COD Load 

(pounds) 

COD Load 

Reduction for 

20% Collection 

and Control 

Scenario 

(pounds) 

COD Load 

Reduction for 

40% Collection 

and Control 

Scenario 

(pounds) 

1130 San Antonio International 1.0000 0 121,626 23,717 47,434 

1131 Wilkes-Barre/Scranton 

International 

2.6815 0 405,801 79,131 158,262 

1133 Phoenix Sky Harbor 

International 

1.0000 20 0 0 0 

1135 Lafayette Regional 6.6425 0 14,201 8,521 8,521 

1136 General Mitchell International 1.0000 44 852,970 0 0 

1137 Dallas Love Field 1.0000 40 213,039 0 0 

1138 Detroit Metropolitan Wayne 

County 

1.0000 ≥60 0 0 0 

1139 Philadelphia International 1.0000 ≥60 1,436,522 0 0 

1140 Memphis International 1.0000 0 1,946,410 379,550 759,100 

1141 Ronald Reagan Washington 

National 

1.0000 40 1,229,789 0 0 

1142 Washington Dulles 

International 

1.0000 40 5,686,802 0 0 

1143 San Francisco International 1.0000 ≥60 0 0 0 

1144 Central Wisconsin 3.0156 0 416,170 81,153 162,306 

1145 Newark Liberty Intl 1.0000 0 10,762,687 2,098,724 4,197,448 

1146 Northwest Arkansas Regional 1.8782 0 293,595 57,251 114,502 

1147 Raleigh-Durham Intl 1.0000 0 977,382 190,589 381,179 

1148 Kansas City Intl 1.0000 40 1,200,632 0 0 

NA – Ketchikan was sent an airport questionnaire but did not respond. 

Sources: Airport Deicing Loadings Database. (USEPA, 2010); ADF Capture and Control Efficiency Review 

Memorandum. (ERG, 2011) 

* The airport post-questionnaire has installed deicing pads; high BOD stormwater is sent to a POTW. 

For each scenario, EPA estimated no load reductions for the airport if it collects and 

controls more than the required percentage of available ADF (e.g., for the 20 percent efficiency 

scenario, if an airport currently collects and controls 20 percent or more of available ADF, no 

load reductions were estimated for the airport). Model airports that currently collect the required 

percentage of available ADF either treat it to the required discharge levels, discharge the 

collected ADF to a POTW, or send it off-site and are assumed to be in compliance with any 

numeric effluent limitation. 

EPA assumed that airports that used small quantities of ADF (less than 5,000 gallons of 

normalized ADF), as described below in Section 10.1, would collect and haul away the required 

percentage of ADF instead of collecting it for on-site treatment. For more information, refer to 

the Airport Deicing Loadings Calculations memorandum (ERG, 2008b). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

107 

9.3 Airfield Deicing Pollutant Loading

This section presents EPA’s methodology for estimating airfield deicing pollutant loads 

using airport questionnaire data on airfield chemical use. 

9.3.1 Estimate the Amount of Applied Deicing Chemical 

In the airport questionnaire, EPA requested that airport personnel report the usage 

amount, concentration, and brand name of the following pavement deicing materials for the 

2002/2003, 2003/2004, and 2004/2005 deicing seasons: 

• Urea; 

• Potassium Acetate; 

• CMA; 

• Sodium Acetate; 

• Sand; 

• Sodium Formate; 

• EG-Based Fluids; 

• PG-Based Fluids; and 

• Other: (Specify). 

EPA evaluated the data provided for each reported chemical to determine the most 

appropriate way to estimate the average amount used over the three winter seasons reported. In 

addition, EPA read the comments provided by the airport personnel to determine any extenuating 

circumstances that affect chemical use. For example, airport personnel may have reported that 

urea was replaced with potassium acetate at the airport during the three years reported. In this 

case, EPA used the potassium acetate average in the loadings estimate and did not use any of the 

urea data to better represent the airport’s current practices. Ninety airports reported pavement 

deicing chemical usage values to EPA in their questionnaire responses. 

Table 9-6 shows the three-year average pavement deicing chemical usage EPA calculated 

from the reported data (normalized to pure chemical) by airport and chemical. In the 

questionnaire, airports reported pounds or gallons of pavement deicing chemical used along with 

the concentration of the chemical. If airport personnel reported a volume of chemical in the 

airport or airline detailed questionnaire, EPA multiplied the reported volume by the reported 

deicing chemical strength and the chemical density. 

No airports reported using CMA. Multiple airports reported using sand, but these data are 

not included in Table 9-6, because sand was not included in the loads analysis. Only one airport 

reported using granular potassium acetate. Potassium acetate (in the liquid form) is the most 

commonly used pavement deicing chemical. 
108 

Technical Development Document for Effluent Limitation Guidelines and Standards for the Airport Deicing Category Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-6. Three-Year Average Amount of Pavement Deicing Chemical Usage, in Poun

Airport 

ID Airport Name 

EG-Based 

Fluids 

Granular 

Potassium 

Acetate 

Potassium 

Acetate 

Sodium 

Acetate 

Sodium 

Formate 

P

1006 Chicago O'Hare Intl 0 0 655,284 0 0 4,1007 Yeager 0 0 0 2,560 0 1010 Fairbanks Intl 0 0 197,024 0 0 1011 Lambert - St Louis Intl 0 0 5,119,502 0 0 1012 Ted Stevens Anchorage Intl 0 0 1,266,417 0 0 1013 Wiley Post-Will Rogers Mem 0 0 0 0 0 1014 Albuquerque Intl Sunport 0 0 4,586 0 0 1016 Tri - State/Milton J Ferguson Field 0 0 27,089 0 0 1017 Austin Straubel Intl 0 0 38,121 0 0 1018 Piedmont Triad Intl 0 0 53,938 0 0 1020 Hartsfield - Jackson Atlanta Intl 0 0 314,456 0 0 1021 Buffalo Niagara Intl 0 0 0 0 7,760 1022 Fort Wayne Intl 0 0 268,772 0 0 1023 Seattle - Tacoma Intl 0 0 97,914 696 0 1024 Indianapolis Intl 0 0 783,038 470,667 0 1026 Dallas/Fort Worth Intl 0 0 18,179 0 0 1028 Denver Intl 0 0 3,526,704 0 0 1029 La Guardia 0 0 1,118,145 1,676 0 1031 Richmond Intl 0 0 284,770 17,000 0 1032 Austin - Bergstrom Intl 0 0 17,483 0 0 1036 Baltimore - Washington Intl 0 0 1,178,861 257,280 156,800 1041 Glacier Park Intl 0 0 0 0 0 1043 Ralph Wien Memorial 0 0 38,870 0 0 1044 Roanoke Regional/Woodrum Field 0 0 109,044 0 0 1050 Aspen - Pitkin County/Sardy Field 0 17,000 46,732 0 0 1052 Wilmington Intl 0 0 0 0 0 1053 General Edward Lawrence Logan Intl 1,217,300 0 0 0 0 
109 

Technical Development Document for Effluent Limitation Guidelines and Standards for the Airport Deicing Category Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-6 (Continued) 

Airport 

ID Airport Name 

EG-Based 

Fluids 

Granular 

Potassium 

Acetate 

Potassium 

Acetate 

Sodium 

Acetate 

Sodium 

Formate 

P

1057 Will Rogers World 0 0 49,603 2,910 0 1058 Gerald R Ford Intl 0 0 66,341 0 8,568 1059 Greater Rochester Intl 0 0 294,634 0 0 1063 Evansville Regional 0 0 29,065 0 0 1065 Albany Intl 0 0 196,535 148,500 0 1066 Salt Lake City Intl 0 0 173,169 0 0 1068 Eppley Airfield 0 0 289,288 9,474 0 1069 Cleveland – Hopkins Intl 0 0 2,456,657 190,055 6,117 1070 City of Colorado Springs Municipal 0 0 224,598 0 0 1071 Tweed - New Haven 0 0 0 291 0 1074 South Bend Regional 0 0 0 0 0 1078 Nashville Intl 0 0 163,779 0 0 1079 Manchester 0 0 398,780 0 0 1080 Syracuse Hancock Intl 0 0 11,792 0 0 1082 Trenton Mercer 0 0 12,393 0 4,704 1084 Bismarck Municipal 0 0 16,114 0 0 1085 Waterloo Municipal 0 0 0 0 0 1088 Outagamie County Regional 0 0 229,290 0 0 1089 John F Kennedy Intl 0 0 170,330 3,460,831 0 1090 Boise Air Terminal/Gowen Field 0 0 98,582 0 0 1094 Boeing Field/King County Intl 0 0 10,255 0 0 1095 Chicago Midway Intl 0 0 1,397,274 0 0 1098 Aberdeen Regional 0 0 17,489 0 0 1100 Toledo Express 0 0 240,209 0 0 1101 Portland Intl 0 0 256,478 10,292 211,183 1103 Juneau Intl 0 0 0 0 0 
110 

Technical Development Document for Effluent Limitation Guidelines and Standards for the Airport Deicing Category Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-6 (Continued) 

Airport 

ID Airport Name 

EG-Based 

Fluids 

Granular 

Potassium 

Acetate 

Potassium 

Acetate 

Sodium 

Acetate 

Sodium 

Formate 

P

1104 Nome 0 0 39,307 0 0 1105 Spokane Intl 0 0 240 0 0 1107 Pittsburgh Intl 0 0 1,198,425 13,333 89,507 1108 Louisville Intl - Standiford Field 0 0 762,020 0 109,760 1109 Airborne Airpark 0 0 1,916,877 0 1,809,373 1110 Aniak 0 0 0 0 0 1111 Port Columbus Intl 0 0 623,773 0 7,161 1112 Deadhorse 0 0 12,229 0 0 1113 Cincinnati/Northern Kentucky Intl 0 0 3,050,218 0 4,000 1114 Stewart Intl 0 0 78,614 2,520 0 1116 Reno/Tahoe Intl 0 0 42,583 0 0 1117 Cherry Capital 0 0 63,909 0 0 1118 Bethel 0 0 0 0 0 1119 Rickenbacker Intl 0 0 71,919 0 37,782 1120 Rapid City Regional 0 0 0 0 0 1121 Theodore Francis Green State 0 0 160,532 0 0 1123 James M Cox Dayton Intl 0 0 174,912 0 0 1124 Des Moines Intl 0 0 340,660 139,033 0 1126 

Minneapolis /St Paul Intl/Wold - Chamberlain 0 0 1,273,019 82,667 0 

1128 Charlotte/Douglas Intl 0 0 109,356 0 0 1129 Bradley Intl 0 0 443,282 223,150 0 1136 General Mitchell Intl 0 0 1,275,038 0 127,400 1137 Dallas Love Field 0 0 218 0 0 1138 Detroit Metropolitan Wayne County 0 0 1,851,138 0 0 1139 Philadelphia Intl 0 0 0 0 0 
111 

Technical Development Document for Effluent Limitation Guidelines and Standards for the Airport Deicing Category Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

Table 9-6 (Continued) 

Airport 

ID Airport Name 

EG-Based 

Fluids 

Granular 

Potassium 

Acetate 

Potassium 

Acetate 

Sodium 

Acetate 

Sodium 

Formate 

P

1140 Memphis Intl 0 0 496,699 74,325 0 1141 Ronald Reagan Washington National 0 0 319,347 34,000 0 1142 Washington Dulles Intl 0 0 2,430,542 619,868 0 1144 Central Wisconsin 1,858 0 59,419 0 0 1145 Newark Liberty Intl 0 0 2,657,040 6,143 0 1146 Northwest Arkansas Regional 243,723 0 0 0 0 1147 Raleigh - Durham Intl 0 0 0 0 0 1148 Kansas City Intl 0 0 597,465 4,573 0 1149 Fort Worth Alliance 0 0 5,241 0 0 1150 Greater Rockford 0 0 311,914 0 0 1151 Kalamazoo/Battle Creek Intl 0 0 0 4,000 0 1153 Akron - Canton Regional 0 0 20,073 162 0 

Source: Airport Deicing Loadings Database (USEPA, 2010). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

9.3.2 Calculate the Amount of Pollutant Load Associated with the Applied Chemical 

As airfield deicing chemicals break down in the environment, they (like aircraft deicers) 

result in increased COD and BOD discharges. EPA calculated the amount of COD associated 

with the degradation of the applied pavement deicing chemicals. Because pavement deicers 

containing urea will also break down into ammonia, EPA also calculated the amount of ammonia 

associated with the degradation of these deicers. 

As with the aircraft deicers, EPA determined it would not be suitable to use empirical 

data to estimate loadings and decided to calculate loadings based on standard chemical 

information and stoichiometric equations. 

Determine the ThOD of Each Chemical 

As with aircraft deicers, the ThOD estimate was based on the molecular formula of the 

chemical and the stoichiometric equation of the breakdown of the chemical to the end products 

of carbon dioxide and water. Table 9-7 lists the calculated ThOD for each chemical in airfield 

deicer. 

Table 9-7. ThOD Calculations for Airfield Deicing Chemicals 

Deicing Compound 

Molecular 

Formula Stoichiometric Formula 

ThOD (Moles of O2

per Mole of Deicing

Compound) 

EG C2H6O2 2[C2H6O2] + 5 O2 Æ 4 CO2 + 6 H2O 2.5 

Urea N2H4CO N2H4CO + 4 O2 Æ 2 HNO3 + CO2 + H2O 4.0 

Potassium acetate KC2H3O2 [C2H3O2] ̄ + 1.75 O2 Æ 2 CO2 + 1.5 H2O 1.75 

Sodium acetate NaC2H3O2 [C2H3O2] ̄ + 1.75 O2 Æ 2 CO2 + 1.5 H2O 1.75 

Calcium magnesium acetate C8H12CaMgO8 [C8H12O8]

4

 ̄ + 7 O2 Æ 8 CO2 + 6 H2O 7.0 

Sodium formate NaHCO2 2[HCO2] ̄ + 0.5 O2 Æ 2 CO2 + H2O 0.25 

Determine the COD of Each Chemical 

EPA next determined the COD loading associated with the chemical’s degradation. EPA 

assumed that the chemical would completely degrade in the environment over time and therefore 

the calculated ThOD load would be equivalent to the COD load. EPA estimated the COD load 

associated with each reported chemical based on the calculated mass of the chemical purchased, 

the molecular weight of the chemical, the ThOD, and the molecular weight of oxygen, using the 

equation below: 

grams 434

pound

O of moles

O of grams Molecular O Weight chemical of moles

O of moles ThOD

chemical of grams

chemical of moles Molecular Chemical Weight pound

grams 434 (pounds) Load COD (pounds) Chemical

2

2

2

2 ⎟×

⎠

⎞ ⎜

⎝

⎛ ⎟×

⎠

⎞ ⎜

⎝

⎛ ×

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ = × ×

 (9-1) 

112 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

9.3.3 Estimate the Amount of Baseline Pollutant Load that is Discharged Directly 

As pavement deicing chemicals are applied at a large variety of areas at an airport, the 

amount of pavement deicers being directly discharged could range from close to 100 percent on 

pavement areas near outfall drains, to nearly 0 percent for chemicals that may fall onto grassy 

areas and infiltrate into the ground during a thaw. Estimating a percentage of direct discharge 

release of pavement deicers at a particular airport is difficult without performing a detailed study 

of each airport. Therefore, EPA assumed 100 percent direct discharge of pavement deicers to 

represent the maximum possible amount of discharge. 

9.3.4 Estimate Pollutant Reductions for Each EPA Collection/Control Scenario 

Urea COD Load Reduction 

As described in section 9.3.2, EPA calculated the COD load associated with urea use at 

the surveyed airports. EPA then evaluated the amount of potassium acetate that would be 

required to replace the current average urea use using a comparison of application rates under 

varying winter conditions (see EPA’s Urea/Potassium Acetate memorandum (ERG, 2010) for the 

details of this analysis). Based on the COD load associated with the equivalent potassium acetate 

use, EPA determined the potential reductions in COD load. Table 9-8 presents by airport the 

COD load associated with urea use, the COD load associated with a switch to potassium acetate 

use, and the potential COD load reduction that would result from airfield product substitution. 

Urea Ammonia Load Reduction 

Because ammonia is not associated with potassium acetate use, the amount of ammonia 

reduction from a urea product substitution is equal to the amount of ammonia associated with 

urea usage. 

The following equation expresses the breakdown of urea to ammonia: 

 N2H4CO + H2O Æ 2 NH3 + 2 H2O + CO2

EPA estimated the ammonia load associated with urea based on the equation above, the 

mass of urea use, and the molecular weights of urea and ammonia, using the equation below: 

grams 434

pound

ammonia of mole

ammonia grams Molecular Ammonia Weight urea of mole

ammonia of moles 2

urea of grams

urea of mole Molecular Urea Weight pound

grams 434 (pounds) Load Ammonia (pounds) Urea

⎟×

⎠

⎞ ⎜

⎝

⎛ ⎟×

⎠

⎞ ⎜

⎝

⎛ ×

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ = × × (9-2) 

Table 9-8 presents by airport the potential ammonia load reduction that would result from 

airfield product substitution. 

113 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

114 

Table 9-8. Baseline Ammonia and COD Load and Potential Load Reduction Associated 

with the Discontinued Use of Urea as an Airfield Deicing Chemical for In-Scope Airports 

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Urea Load 

(lbs of 

COD) 

Equivalent 

Potassium 

Acetate Load 

(lbs of COD) 

Potential 

Load 

Reduction 

(lbs of 

COD) 

Potential 

Load 

Reduction

(lbs of 

Ammonia)

1007 Yeager 2.1508 58,644 16,172 42,471 15,572

1010 Fairbanks Intl 1.0000 707,559 195,127 512,432 187,883

1012 Ted Stevens Anchorage Intl 1.0000 5,359,760 1,478,087 3,881,674 1,423,212

1017 Austin Straubel Intl 2.3269 95,606 26,366 69,240 25,387

1018 Piedmont Triad Intl 1.0000 197,491 54,463 143,028 52,441

1022 Fort Wayne Intl 1.9682 608,551 167,823 440,728 161,593

1041 Glacier Park Intl 3.1409 710 196 514 189

1043 Ralph Wien Memorial 1.0000 21,312 5,877 15,435 5,659

1053 General Edward Lawrence 

Logan Intl 

1.0000 21,774 6,005 15,769 5,782

1066 Salt Lake City Intl 1.0000 2,389,572 658,984 1,730,588 634,519

1074 South Bend Regional 2.1417 69,136 19,066 50,070 18,358

1079 Manchester 1.0000 78,499 21,648 56,851 20,844

1090 Boise Air Terminal/Gowen 

Field 

1.5043 575,214 158,629 416,584 152,740

1103 Juneau Intl 1.0000 1,018,715 280,936 737,779 270,506

1105 Spokane Intl 1.5192 1,061,339 292,690 768,648 281,824

1114 Stewart Intl 2.8661 323,516 89,218 234,299 85,905

1116 Reno/Tahoe Intl 1.0000 23,840 6,574 17,265 6,330

1118 Bethel 1.0000 143,501 39,574 103,927 38,105

1128 Charlotte/Douglas Intl 1.0000 319,432 88,091 231,340 84,821

1129 Bradley Intl 1.0000 35,692 9,843 25,849 9,478

1141 Ronald Reagan Washington 

National 

1.0000 166,234 45,843 120,391 44,141

1144 Central Wisconsin 3.0156 263,076 72,550 190,526 69,856

1146 Northwest Arkansas 

Regional 

1.8782 38,362 10,579 27,782 10,186

1147 Raleigh - Durham Intl 1.0000 134,976 37,223 97,753 35,841

Source: Airport Deicing Loadings Database. (USEPA, 2010). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 9 – Pollutant Loadings and Pollutant Load Reduction Estimates 

115 

9.4 References 

ERG. 2008a. Memorandum from Steve Strackbein (ERG) to Brian D’Amico and Eric Strassler 

(U.S. EPA). The Development of Snow and Freezing Precipitation (SOFP) Days and the Aircraft 

Deicing and Anti-icing Fluid (ADAF) Factor. (January 16). DCN AD00856. 

ERG. 2008b. Memorandum from Cortney Itle (ERG) to Brian D’Amico (U.S. EPA). Airport 

Deicing Loadings Calculations. (April 17). DCN AD001140. 

ERG. 2010. Memorandum from Steve Strackbein and Mary Willett (ERG) to Brian D’Amico 

and Eric Strassler (U.S. EPA). Estimated Costs for Transition to Liquid Airfield Deicing 

Application from Solid Airfield Deicing. (October 8). DCN AD01252. 

ERG. 2011. Memorandum from Cortney Itle and Mary Willett (ERG) to Brian D’Amico (U.S. 

EPA). ADF Collection and Control Efficiency Review. (June 15). DCN AD01270. 

Switzenbaum, et al. 1999. Workshop: Best Practices for Airport Deicing Stormwater. DCN 

AD00893. 

USEPA. 2008. Airport Deicing Operations ADF Usage Database. U.S. Environmental 

Protection Agency. Washington, D.C. DCN AD001141. 

USEPA. 2010. Airport Deicing Loadings Database. U.S. Environmental Protection Agency. 

Washington, D.C. DCN AD01257. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

116 

10. TECHNOLOGY COSTS 

This section presents EPA’s estimates of costs for the Airport Deicing Category to 

implement the control and treatment technologies EPA considered as technology bases for 

existing airports in the final rule. EPA estimated the compliance costs for each control and 

treatment technology to determine potential economic impacts on the industry. EPA also 

weighed these costs against the pollutant load reduction benefits resulting from the control and 

treatment technologies. 

This section discusses the following information: 

• Section 10.1 – EPA’s costing approach using airport-specific data as model 

airports; 

• Section 10.2 – EPA’s methodology for estimating aircraft deicing costs associated 

with the collection and treatment of ADF-contaminated stormwater, including an 

overview of EPA’s cost model and example calculations showing how the model 

estimates costs; 

• Section 10.3 – EPA’s methodology for estimating airfield deicing costs associated 

with urea substitution; 

• Section 10.4 – Other compliance-related costs; and 

• Section 10.5 – A summary of EPA’s annualized costs evaluated for the final rule. 

10.1 Costing Approach

The Agency used a model-site approach to estimate costs for the Airport Deicing 

Category. A model airport is an operating airport for which EPA estimated site-specific 

compliance costs. In general, these include sites for which EPA has questionnaire responses. 

EPA selected an airport-by-airport approach to estimate compliance costs based on a comparison 

of information from the model airports, as opposed to a more generalized approach, to better 

characterize the current control and treatment systems in place for ADF contaminated 

stormwater and to account for current site conditions and airport operations. 

For each model airport, EPA developed both capital and operating and maintenance costs 

to reduce pollutant discharges from aircraft deicing and from airfield deicing. EPA combined 

these costs for each model airport to estimate total costs of each regulatory option evaluated. 

EPA then applied a weighting factor to the costs for each airport to estimate national costs for 

each option. A description of the weighting factors for the Airport Deicing Category is in DCN 

AD01234. 

EPA estimated compliance costs for the model airports using information provided in the 

airport questionnaire, the detailed airline questionnaire, and from individual airports and vendors. 

For any given model airport, the estimated costs may deviate from those that the airport would 

actually incur. However, EPA considers the compliance costs to be accurate when aggregated on 

an industry-wide basis. These compliance costs are generally broken down into three categories, 

costs associated with aircraft deicing, costs associated with airfield deicing, and costs with 

documenting compliance with today’s regulation. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

117 

10.2 Aircraft Deicing Costs

This section describes the general methodology for estimating costs for ADF collection 

and treatment, including the Airport Deicing Cost Model design and the development of cost 

equations that use model-airport-specific inputs. Components of the aircraft deicing costs include 

collection, containment and storage, and treatment costs. EPA estimated capital and annual 

operating costs for each of these costing components, which were then amortized to generate 

model-airport-specific annualized costs. 

10.2.1 Overview of the ADF Collection and Treatment Airport Deicing Cost Model 

Managing ADF-contaminated stormwater is a multistep process. EPA developed an 

Airport Deicing Cost Model to estimate deicing stormwater control costs for each of these steps 

and the various alternatives within each step. Costs for each selected alternative are combined for 

each airport included in the costing effort to develop cost estimates for the different EPA control 

and treatment technology options considered for the final rule. For example, regulatory costs at 

an airport may include a combination of alternatives from the collection, containment and 

storage, and treatment categories. 

The EPA regulatory options were based on requiring an airport to collect and control 

deicing stormwater through a variety of mechanisms. Based on information provided in the 

airport questionnaire and data gathered during EPA’s engineering site visits to various airports, 

EPA decided to estimate costs for three collection technologies. Those collection technologies 

included GCVs alone, a combination of plug and pump system with GCVs, and use of CDPs. 

Each collection alternative is expected to provide a different level of collection efficiency for 

ADF-contaminated stormwater. In the final rule, EPA decided to estimate costs for only two of 

these technologies, GCVs and plug and pump with GCV, in part due to concerns that spaceconstrained airports may not be able to incorporate CDP because of FAA requirements on their 

design and siting. EPA estimates that using only GCVs to collect ADF-contaminated stormwater 

from areas within the airport where aircraft are deiced will collect 20 percent of the available 

ADF. Adding a plug and pump system in combination with GCVs to the existing stormwater 

drainage system is expected to collect 40 percent of the available ADF. 

Once ADF-contaminated stormwater has been collected, the airport has a variety of 

alternatives for control, including disposal at a POTW, off-site recycle and recovery, on-site 

recycle and recovery, or on-site treatment and disposal. Each of these alternatives should be 

considered by an airport when selecting the appropriate method to manage collected ADF. For 

the airport deicing rulemaking option analysis, EPA selected the AFB reactor treatment system 

as the basis of costs because of its demonstrated capability to destroy glycols and generate an 

effluent suitable for direct discharge. Although AFB treatment systems may be more expensive 

to install and operate when compared to other treatment alternatives, EPA’s basis of all treatment 

conducted via AFB should provide a conservative cost estimate for individual airports to treat 

spent ADF. For costing purposes, EPA assumed that all model airports requiring improvement to 

meet the collection requirements, except for low ADF usage airports, would install an AFB 

system. For airports that occasionally deice aircraft primarily to remove frost, installing 

permanent collection and treatment equipment for ADF would not be practical. Instead, EPA 

assumes these airports would use contractors to provide deicing stormwater collection and 

removal services. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

118 

EPA assumed that all airports that are required to collect additional ADF will need onsite containment or storage for the collected deicing stormwater prior to treatment in an AFB 

system. The final rule does not require nor is it based on collecting the full volume of wastewater 

generated in a deicing season. Rather, storage is included as part of the technology basis for flow 

and/or pollutant equalization to support the AFB treatment system. In these cases, containment 

and storage selections can include ponds, underground storage tanks, aboveground storage tanks, 

or temporary storage tanks (e.g., frac tanks). EPA decided to estimate costs for aboveground 

storage tanks in the final rule because they will have less of an impact on subsurface utilities for 

which EPA does not have site-specific information. In addition, FAA discourages airports from 

installing new stormwater retention ponds, as they can be a lure for birds, which are a safety 

hazard for aircraft. Airports may also require additional stormwater piping to transfer collected 

ADF-contaminated stormwater from aircraft application areas to storage tanks. 

The airport deicing cost model considers each of these alternatives to develop a costing 

scheme for collecting and containing ADF-contaminated stormwater at each model airport. The 

Airport Deicing Cost Model also takes into account the effectiveness of each model airport’s 

current control and treatment program for ADF-contaminated stormwater to determine if 

additional costing is requiredto comply with the regulatory options considered for the final rule. 

In general, EPA’s approach to develop costs for the model airports consists of the 

following steps: 

• Step 1: Develop cost equations for each collection, storage, and treatment 

alternative evaluated for the final rule; 

• Step 2: Estimate an airport’s current level of ADF-contaminated stormwater 

collection based on information provided in the airport questionnaire; 

• Step 3: Apply the collection and treatment cost equations for the various 

components to those airports that currently collect and manage less than the 

control and treatment scenario percentage being evaluated to determine airportspecific capital and annual costs for that scenario and each component; and 

• Step 4: Estimate total airport-specific annualized costs for each component of the 

airport scenario for each control and treatment scenario. 

10.2.2 Airport Deicing Cost Model Equation Development 

Based on the available data, EPA developed cost equations for the collection, storage, 

and treatment technologies that could be applied to those model airports not currently achieving 

the required collection percentage. In general, the Agency developed cost equations using cost 

data from the BAT model airports representing their entire system rather than attempting to 

estimate costs for individual components. EPA believes using system wide costs is a better way 

to estimate costs for this regulatory effort because all installed capital and annual operating costs 

are rolled under a single value, eliminating the concern that specific components may not have 

been included and allowing for more robust estimates. For example, EPA did not prepare costs 

for individual components within the AFB treatment system such as reaction vessels, piping, 

pumps, flow meters, and buildings, but instead estimated costs for the entire treatment system. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

119 

EPA used the cost data from the model airports and information supplied by equipment vendors 

along with airport-specific information to develop normalized cost equations that could then be 

projected to other airports based on common variables. The sections below describe the 

development of the normalized cost equations for the collection, transfer and storage, and 

treatment system alternatives evaluated by EPA. 

10.2.2.1 ADF Collection 

Airports use ADF-contaminated stormwater collection alternatives to achieve the targeted 

ADF collection percentage. Collection alternatives that EPA selected for costing include 

developing a winter operations plan to help manage ADF use and maximize recovery of 

available ADF, using glycol collection vehicles to collect ADF from surfaces following aircraft 

deicing, and using a plug and pump system to collect ADF. EPA estimates that airports using 

GCVs can collect 20 percent of the available ADF, and airports using plug and pump in 

combination with GCVs can collect 40 percent of the available ADF. Airports with deicing pads 

are expected to collect more than 40 percent of the available ADF and would therefore comply 

with the control alternatives evaluated for this final rule. 

Winter Operations Plan 

A large number of airports currently have a Stormwater Pollution Prevention Plan 

(SWPPP) that includes deicing operations during the winter months. However, these SWPPPs 

may not provide specific guidance for achieving the regulatory requirements considered for the 

final deicing rule. Therefore, EPA envisions that airports will supplement their SWPPP with a 

specific winter operations plan that includes information such as methods to verify the 

percentage of ADF collection, standard operating procedures for ADF collection technology 

systems, and training information for system operators. Once airports have assessed specific 

winter operations to collect and control deicing stormwater, they can implement a control and 

treatment strategy to decrease the amount of ADF leaving the airport through stormwater 

outfalls. 

Costs to develop a winter operations plan will likely vary depending on the type of ADF 

collection system. EPA assumed that airports targeting 20 percent collection using GCVs would 

require 120 hours of engineering labor to prepare the plan and those airports targeting 40 percent 

ADF collection using a combination of GCVs with plug and pump would requireapproximately 

240 hours of engineering labor. Based on an engineering rate of $100/hour obtained from the 

airport questionnaire, the one-time costs to prepare a winter operations plan for 20 percent and 

40 percent ADF capture would be $12,000 and $24,000, respectively. 

GCVs 

Airports use GCVs to collect ADF-contaminated stormwater from various locations 

including gate and apron areas, taxi areas, and centralized deicing areas. GCVs can be either 

truck-mounted systems or tow-behind units. Drain covers that bond to surfaces to quickly seal 

off drains are often used in conjunction with GCVs in the area where aircraft are deiced to allow 

the GCVs to collect high-concentration spent deicing fluid. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

120 

To estimate total capital costs for purchasing GCVs and annual operating and 

maintenance (O&M) costs for operating GCVs, EPA used information provided by airports in 

the airport questionnaire. 

All airports that provided costing information, regardless of hub size, maintained three or 

less GCVs. EPA used the information presented in Table 10-1 to estimate the number of GCVs 

by airport hub size. The Agency assumes that Non-hub, Small Hub, and Medium Hub airports 

can operate effectively and efficiently with two GCVs and that Large Hub airports can operate 

effectively and efficiently with three GCVs. Additional details regarding costs for GCVs is 

provided in a memorandum entitled Estimated Capital and O&M Costs for Glycol Collection 

Vehicle Operation (ERG, 2010). 

Control of drainage while operating GCVs will vary by airport. For purposes of 

estimating GCV costs, EPA assumed that airports use drain covers in combination with the GCV 

operation. Variables that could impact drainage control costs include the size of drain covers and 

number of drains to be covered. Because these variables are airport-specific and details are not 

available, EPA was unable to develop a specific approach to estimate the cost of drain covers 

and the labor needed to install them. EPA has instead incorporated a cost increase factor of 20 

percent to the annual O&M cost for using GCVs. EPA assumes that a 20 percent increase in 

O&M costs for GCVs will cover costs to purchase and replace drain covers and labor to install 

and remove the drain covers as needed. 
121 

Technical Development Document for Proposed Effluent Limitation Guidelines and Standards for the Airport Deicing Category Section 10 – Technology Costs

Table 10-1. GCV Capital and O&M Costs 

Site ID Hub Size 

Estimated 

ADF Usage 

(gal/yr) 

Number 

of GCVs

Total GCV 

Capital Costs

Capital Cost 

Base Year 

2007 GCV 

Capital Cost

Total GCV 

Annual Cost

Annual 

Cost 

Base 

Year 

2007 GCV 

Annual 

Cost 

($/yr) 

1136 Medium 152,944 1 $361,355 2001 $415,558 $15,268 2004 $16,184 1012 Medium 420,735 1 $273,840 2001 $314,916 $80,000 2005 $82,400 1113 Large 722,995 1 $250,000 1997 $317,500 $5,000 2005 $5,150 1066 Large 570,540 1 $353,000 2004 $374,180 1101 Medium 112,086 2 $700,000 1996 $910,000 $43,236 2004 $45,831 1021 Medium 284,654 2 $530,000 2001 $609,500 $0 1036 Large 323,623 1 $283,463 2006 $283,463 $214,516 2004 $227,387 1065 Small 125,775 1 $325,000 2005 $334,750 $45,000 2005 $46,350 1031 Small 59,337 2 $518,300 2001 $596,045 $35,000 2005 $36,050 

AVERAGE 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

122

Plug and pump with GCVs 

Two airports provided sufficient information to estimate costs for a plug and pump type 

collection system. During the 2005 deicing season, the first airport used sewer balloons at eight 

locations, storm sewer shutoff valves at four locations, and two catch basin inserts. In addition, 

this airport utilized two GCVs for ancillary glycol collection; one is a traditional truck-based 

GCV and the other is a GCV unit (a V-Quip Ramp Ranger) that is towed behind a tractor. The 

estimated capital cost for this airport’s plug and pump system (including the GCVs) is 

approximately $790,000. The plug-and-pump system operated at this airport prevents ADFcontaminated stormwater from discharging through three deicing stormwater outfalls (USEPA, 

2006a). 

The second airport operates 16 plug and pump locations that prevent ADF-contaminated 

stormwater from leaving the airport through a maximum of five outfalls. These plug and pump 

operations include plugging the associated drainage pipes and pumping out these drains with 

dedicated pumping trucks. According to the airport, the annual budget to operate the plug and 

pump system is approximately $1,300,000. This cost includes permit monitoring, glycol 

management, the pumping contractor, plus other miscellaneous costs (ERG personnel 

communication, May 3, 2007). Because the glycol collection system at this airport is contracted 

to a third party, all costs to the airport are reoccurring annual costs. Therefore, these O&M costs 

are likely over estimates compared to airports that do not contract out their glycol collection 

system operation. 

To estimate both capital and annual O&M costs for other airports where plug and pump 

collection may be applicable, EPA normalized the costs based on the number of deicing outfalls. 

EPA assumed that the number of deicing outfalls is related to the number of areas where aircraft 

deicing occurs, so that in general an airport that has a greater number of discontiguous deicing 

areas will have a greater number of deicing outfalls. EPA estimated that more deicing areas 

would indicate the need for additional costs associated with removing ADF from those areas. 

Table 10-2 presents the normalized capital and annual O&M costs for the plug and pump 

collection system at the airports for which EPA had costing data. 

Table 10-2. Normalized Capital and O&M Costs for the Plug and Pump Collection 

System 

Airport 

Deicing 

Outfalls 

Total Capital 

Cost 

(2006 $)1

Annual O&M Cost 

(2006 $) 

Normalized 

Capital Cost 

($/outfall) 

Normalized Annual 

O&M Cost 

($/outfall) 

Airport 1 3 $790,000 NA $263,400 NA 

Airport 2 5 NA $1,300,000 NA $260,000 

NA – Data not available. 

Contract Hauling of ADF-Contaminated Stormwater 

For airports that occasionally deice aircraft primarily to remove frost, installing 

permanent collection and treatment equipment for ADF-contaminated stormwater would not be 

practical. Instead, EPA assumes these airports would contract out deicing stormwater collection 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

123

and removal and their costs would not vary between the 20 percent and 40 percent collection/

control scenarios. This costing approach impacts the following airports: 

• Ontario International airport in California; 

• Birmingham International Airport in Alabama; 

• Montgomery Regional airport in Alabama; 

• Sacramento Mather airport in California; 

• Lovell Field airport in Tennessee; and 

• Lafayette Regional airport in Louisiana. 

These airports reported that they do some deicing, but all reported or are estimated to use 

5,000 gallons/year or less normalized ADF, had less than 100 percent capture of ADFcontaminated stormwater, indicated that they discharged ADF-contaminated stormwater to 

surface waters, but reported no typical deicing months. Specific details regarding the costs for 

occasional removal of ADF-contaminated stormwater by a local contractor is included in a 

memorandum entitled Estimated Annual Costs for Airports with Limited ADF Use (ERG, 2008). 

10.2.2.2 AFB Treatment System 

EPA based the proposed COD discharge limitation on AFB treatment. As such, when 

applicable, EPA determined costs for in-scope facilities to treat collected ADF through an AFB 

system. EPA also included costs for associated storage and transfer piping. 

Transfer Piping 

Piping costs to transfer collected stormwater to holding tanks prior to either on-site or 

off-site ADF management will vary for each airport. Variables that could impact transfer piping 

costs include existing subsurface utilities, soil types, elevation changes, and anticipated peak 

precipitation events. Because each of these variables is airport-specific and the details are not 

available, EPA estimated costs for each airport to construct 10,000 linear feet of new subsurface 

stormwater conveyance piping from various areas around the airport. EPA modified this estimate 

from the proposal’s 1,000 linear feet after considering public comment. 

Elements of a stormwater piping system include subsurface concrete piping, manholes 

and catch basins throughout the system to control the direction of flow. EPA obtained costs for 

individual elements within the system from RSMeans (RS Means, 2010) and adjusted the costs 

to 2006 dollars. The Agency added cost factors for plumbing and site work to the direct costs to 

obtain total installed direct costs. Indirect costs for engineering, permits, scheduling, 

performance bonds, and contractor markups were added to the total installed direct costs. Table 

10-3 shows the estimated installed capital cost for 10,000 linear feet of a new stormwater 

conveyance piping system at an airport is approximately $1,140,000. Details regarding capital 

costs plus indirect cost factors are provided in a memorandum entitled Estimated Capital and 

O&M Costs for Additional Stormwater Piping (ERG, 2010c). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

124

Table 10-3. Estimated Cost for 10,000 Linear Feet of Stormwater Piping 

Description Total Cost 

Trenching for stormwater piping $59,000 

Backfill and compact trench after piping $38,000 

Concrete stormwater piping (18-inch diameter) $310,200 

Manholes/catch basins $137,400 

Manhole frames and covers 28,800 

Plumbing (connectors, extra labor, etc.) $187,500 

Site work (clearing, grading, surveying) $80,300 

Engineering $67,300 

Permits $16,800 

Scheduling $6,700 

Performance bonds $21,000 

Insurance (risk, equipment floater, public liability) $19,300 

Contractor markup (handling, procuring, subcontracting, change orders, etc.) $84,000 

Overhead and profit $84,000 

Total Installed Capital Cost for 10,000’ of Stormwater Piping $1,140,000 

Source: RS Means Heavy Construction Cost Data, 64th Edition, 2010. 

Annual O&M costs for the piping and conveyance system include periodic inspections to 

verify integrity of the piping system. To estimate labor costs for TV inspection of the 18” sewer, 

EPA made a conservative assumption that an airport would inspect 20 percent of the storm sewer 

system annually (2,000 linear feet), at a rate of $1,400 per day (2006 basis). Based on 

engineering experience, a sewer TV crew of two to three persons can inspect approximately 500 

feet of piping per day. At a rate of $1,400/day, the annual airport inspection cost would be 

approximately $5,600. 

Storage Tanks for ADF-Contaminated Stormwater 

The AFB system that forms the basis for today’s COD limitation include storage to 

provide both flow and concentration equalization. Storage tanks are used at airports to equalize 

either flow and/or concentration of ADF-contaminated stormwater prior to treatment in the AFB 

system. The actual size of the storage tank depends primarily on the amount of ADF-impacted 

stormwater generated during precipitation events, the area from which deicing stormwater is 

collected, and the rate the stormwater can be discharged to the AFB. For costing purposes, EPA 

selected aboveground rather than underground storage tanks due to constraints such as existing 

underground utilities or high ground water levels at individual airports. 

EPA obtained storage tank volumes and capital costs when available from five airports in 

the airport questionnaire (USEPA, 2006b). Using normalized ADF usage data for each of these 

airports, EPA normalized tank volumes and costs to the annual ADF use per year to provide an 

equation that could be used to estimate storage tank sizes and costs at other airports. EPA’s 

normalized ADF usage amounts represent ADF amounts without any water dilution. EPA chose 

ADF usage as the costing basis for tank storage because the amount of tank storage needed is 

directly related to the amount of ADF applied for aircraft deicing, which is a function of the 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

125

frequency, duration, and intensity of precipitation events at a particular airport during a deicing 

season. In addition, the storage tanks at each of these airports are used to contain ADFcontaminated stormwater prior to treatment, and therefore the hydraulic capacity has likely been 

designed with equalization requirements (e.g., maximum flow and equalized pollutant 

concentrations) in mind. 

The data in Table 10-4 indicate the volume of storage tanks at the five airports ranges 

between 1.5 million gallons and 8 million gallons, with the average being approximately 4.6 

million gallons. The average unit cost for storage tanks calculated from the data in Table 10-4 is 

$1.67/gallon. The normalized storage tank volume, calculated from the data provided in Table 

10-4, is 11.4 gal/gal ADF use/yr. The basis of the 11.4 gal/gal ADF use/yr factor includes storage 

of ADF-contaminated stormwaters from a variety of collection technologies (including GCVs, 

diversion systems, and deicing pads) that were identified as having glycol concentrations greater 

than 1 percent or in one case greater than 1,000 mg/l BOD. EPA believes that this factor will 

provide sufficient storage volume for those airports required to meet either a 20 or 40 percent 

available ADF collection requirement because the airports forming the basis of the factor have an 

ADF collection percentage greater than the considered requirement. 

Table 10-4. Storage Tank Volumes and Installed Capital Cost for Various Airports 

Airport 

ADF Use 

(gal/yr) 

Total Storage 

Tank Volume 

(gal) 

Storage Tank Volume 

per ADF Use 

(gal/gal/yr) 

Installed 

Capital Cost 

(2006 $) 

Storage Tank 

Capital Cost 

($/gal) 

1 1,043,138 6,520,000 0.4 $795,000 1 $1.89 

2 943,982 5,140,000 2.6 NA NA 

3 715,836 8,000,000 11.2 $9,440,000 $1.18 

4 112,086 2,000,000 17.8 NA NA 

5 60,246 1,500,000 24.9 $2,890,000 $1.93 

AVERAGE 11.4 $1.67 

NA – Not available. 

1

 Cost provided for one 420,000-gallon storage tank. 

To determine if the unit cost for aboveground storage tanks was reasonable, EPA 

compared the $1.67/gallon unit cost to the cost for permanent storage tanks reported in the 

ACRP Fact Sheets (ARCP Fact Sheets). According to Fact Sheet 30, aboveground permanent 

storage tank costs range from $1.25 to $1.75/gallon for tanks ranging in size from 500,000 

gallons to 1 million gallons. Unit costs for storage tanks between 1 million and 2 million gallons 

range from $1.00 to $1.50/gallon. Based on the data in the fact sheets, EPA believes the 

$1.67/gallon unit cost factor should provide a conservative estimate of tank costs. 

The airport questionnaire responses provided limited data to determine the annual O&M 

cost for storage tanks. One airport reported annual O&M costs for its storage tanks ranged 

between $50,000 and $100,000. Using ADF usage information for this airport (281,836 gal/yr) 

and the reported annual O&M cost for the airport ($75,000/yr), EPA calculated the normalized 

annual O&M cost for storage tanks to be $0.27 per gallon of ADF used per year 

($75,000/281,836). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

AFB Treatment Systems 

In the proposed rule, EPA used a linear relationship between ADF use and ADF percent 

collection to predict AFB costs. Public comments raised the issue that such a relationship does 

not consider minimum capital costs for small systems or the economy of scale for larger systems. 

All AFB treatment systems, regardless of size, will require basic components such as chemical 

dosing systems, gas handling systems, sludge handling systems, storage tanks, in-line monitoring 

equipment, and process control systems. For many of these components, cost is independent of 

treatment system size. 

To assist EPA with developing costs for AFB treatment, industry developed a cost curve 

that shows a general relationship between cost and COD load for systems designed to treat 

between 500 and 7,000 lbs/day of COD. As shown in Figure 10-1, the cost per pound of COD 

removal decreases rapidly for larger load removal systems because of the economy of scale with 

the reactor and separator system, and the cost for support buildings and facilities is relatively 

constant and not tied to COD loading. 

y = 275101x-0.6279

0

1000

2000

3000

4000

5000

6000

7000

0 1000 2000 3000 4000 5000 6000 7000 8000

COD Loading (lbs/day)

Capital Cost ($/lb COD/d

a

Figure 10-1. AFB Reactor Capital Cost for Treating ADF-Contaminated Stormwater 

Using the equation in Figure 10-1 developed from industry comments (See Airport 

Council International – North America comments on EPA’s Proposed Rule for Effluent 

Guidelines for the Airport Deicing Category), EPA can estimate the installed capital cost for an 

AFB reactor (excluding storage, transfer piping, and possible land costs) if the COD loading is 

known. To test the accuracy of this equation, EPA compared calculated costs to those provided 

by Albany International Airport (Albany) for their AFB treatment units. According to Albany 

airport staff, the installed cost for their AFB treatment system is approximately $8.1 million 

dollars (2006 $). This cost does not include equalization tanks or ponds prior to the AFB, 

additional stormwater piping to transfer ADF-contaminated stormwater from areas of generation 

to storage, or purchase of additional land to accommodate the AFB treatment reactors or storage. 

Based on Albany’s design COD loading of 5,200 lbs/day, the equation in Figure 10-1 would 

predict an AFB installed cost of $6.6 million dollars (2006 $). Because the estimated cost for the 

Albany AFBs, using industry’s equation, is within + 20 percent of the actual cost provided by 

Albany, EPA concludes the equation shown in Figure 10-1 can be used to predict AFB costs for 

all airports. 

126
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

127

Both the Albany and Akron-Canton (Akron) airports provided annual O&M costs for 

their treatment reactors. According to Albany, its annual O&M cost is approximately 

$510,000/year. Akron has recently constructed its AFB and did not have actual operating data at 

the time of EPA’s costing analysis but did provide estimated annual O&M costs of 

$195,000/year (McQueen, R. and Arendt, T.). Because annual operating costs for an AFB system 

are directly related to the annual amount of ADF use and the collection percentage, EPA 

normalized annual AFB reactor annual operating costs to these two factors. Table 10-5 shows the 

AFB reactor annual O&M costs normalized to annual ADF usage for Albany and Akron. 

Table 10-5. Normalized Annual O&M Costs for the AFB Reactors 

Annual ADF 

Use (gal/yr) 

Estimated Percent 

Capture 1

Annual ADF 

Captured 

Annual O&M 

Cost 

(2006 $/yr) 1

Normalized Annual 

O&M Cost ($/gal 

ADF recovered) 

Albany 125,775 92 115,713 $510,000 $4.40 

Akron 60,264 60 36,200 $195,000 $5.39 

AVERAGE $4.90 

1

 Airport deicing loadings database. 

Land Costs 

EPA has included the opportunity cost of land use for both storage and treatment of 

ADF-contaminated stormwater. EPA’s approach to estimating this cost is to first estimate the 

amount of land needed for storage tanks and the AFB treatment system and then apply an 

opportunity cost per square foot. The opportunity cost assumes the land could potentially be 

leased for some other use by an airport tenant if not being used for the treatment and storage 

system. 

To estimate the area of land associated with the AFB treatment system, EPA obtained 

information on the footprint of the AFB systems at Albany using Google Earth (Google Earth, 

2007). Based on a review of the Google Earth images, EPA estimates the footprint for the AFB 

treatment system is approximately 2.4 acres or 104,544 sq.ft. This area would include the 

reactors, associated buildings, pump houses, roadways and parking areas, etc. 

To predict the amount of land needed for storage tanks, EPA used the following equation 

developed for predicting storage tank costs: 

 Volume of Required Storage Capacity (gal) = ADF Use gal/yr × 13.1 gal/gal/yr 

Combining this equation with the one developed from the figure below allows EPA to 

estimate the minimum footprint for storage tanks at individual airports based on ADF use. The 

equation shown in the figure below is based on storage tanks with a 14-foot sidewall depth. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

Tank Area Versus Storage Volume

y = 0.0095x - 7E-12

R2 = 1

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

0 2,000,000 4,000,000 6,000,000 8,000,000 10,000,000

Storage Capacity (gal)

Area (ft2)

Because storage tanks require a barrier-free area of approximately 20 feet around the 

entire tank for maintenance as well as access roads to the tanks, EPA decided to increase the 

minimum tank footprint by 20 percent.

EPA believes that siting of AFB and deicing stormwater storage systems will require that 

they be placed away from the terminal and main runway area. To estimate the value of this land 

if leased by an airport, EPA obtained leasing information from a number of airports. Based on 

the leasing cost data obtained from these airports, EPA selected an estimated $1.00/sq.ft. cost for 

purposes of the costing model. Additional information on land costs is included in a 

memorandum entitled Estimated Land Requirements and Opportunity Costs for the Anaerobic 

Fluid Bed Treatment System and ADF Stormwater Storage Tanks (ERG, 2010d). 

10.2.3 Development of Airport Deicing Cost Model Inputs 

The key inputs to EPA’s Airport Deicing Cost Model include airport operations data and 

site-specific precipitation and physical feature data for the model airports. 

10.2.3.1 Airport Operations Data 

The primary source of airport operations data used in the calculation of collection and 

treatment costs were responses to the Agency’s 2006 airport questionnaire (U.S. EPA, 2006b). 

EPA entered data from all questionnaire responses into an electronic database that it used to 

determine if any ADF-contaminated stormwater collection and treatment technologies were 

currently utilized and to access reported operations data needed to estimate costs for additional 

collection and treatment. EPA used the following specific data from the questionnaire responses: 

geographical location, aircraft deicing chemical usage, manner/frequency of deicing discharges, 

deicing, and ADF collection operations. 

EPA required the following additional airport operating data not requested in the airport 

questionnaire to estimate costs: annual ADF use and the number of annual nonpropeller aircraft 

128
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

129

departures. EPA collected data on annual ADF usage in its airline detailed questionnaire (U.S. 

EPA 2006). EPA evaluated annual nonpropeller aircraft departures using data from the Bureau of 

Transportation Statistics (BTS). 

10.2.3.2 Precipitation Data and Site Characteristics 

Estimating costs to collect and treat ADF-contaminated stormwater partially depends 

upon the volume of the stormwater. To predict the annual volume of ADF-impacted stormwater 

generated at an airport, EPA used precipitation data along with airport site characteristics and 

assumed ADF-impacted stormwater would be collected from areas where ADF is applied and 

possibly from areas where ADF may drip from the aircraft during taxi and takeoff. EPA obtained 

precipitation data from 1976 to 2006 (30 years) from NOAA for each airport questionnaire 

respondent and then averaged the data by airport to estimate an airport-specific monthly average. 

EPA uses these data, combined with the number of deicing months taken from the questionnaire 

responses, to estimate the average annual amount of precipitation that may be contaminated by 

ADF. 

10.2.4 Airport Deicing Cost Model Design 

This section describes how the Airport Deicing Cost Model uses the capital and annual 

cost equations, in combination with the model input data, to predict costs for each model airport. 

10.2.4.1 Airport Deicing Cost Model Description 

EPA developed the Airport Deicing Cost Model using Microsoft® Access. The model 

uses various tables structured from the airport questionnaire responses to provide input to the 

design equations. EPA designed the model to use a series of “Yes – No” statements and its 

assessment of the current collection efficiency achieved by an airport to build costs, as 

appropriate, based on the appropriate types of collection alternatives needed to achieve the target 

collection efficiency. 

The Airport Deicing Cost Model provides output costs in Microsoft® Excel for each 

selected collection alternative, and the treatment system (piping, storage tanks, and AFB 

treatment system). The outputs include both installed capital cost and annual O&M costs. Airport 

Deicing Cost Model outputs for each airport that is currently not achieving the analyzed percent 

control and treatment of ADF-contaminated stormwater are then used to calculate annualized 

costs by airport. Section 10.2.5 provides more detail regarding cost annualization. The Airport 

Deicing Cost Model collection and control cost output is $0 for those airports which EPA 

estimates are achieving the analyzed option for collection and control of available ADF. EPA’s 

assessment of each airport’s current collection and control percentage is provided in the 

memorandum entitled ADF Capture and Control Efficiency Review (ERG, 2011). 

10.2.4.2 Summary of Airport Deicing Cost Model Equations 

The Airport Deicing Cost Model uses capital and annual cost equations in combination 

with various input parameters to estimate costs for each option’s collection and treatment 

technology at each airport. Table 10-6 summarizes the cost equations used by the model, the 

input variables, and any assumptions used by the model to estimate costs. The equations in Table 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

130

10-6 are based on an airport collecting ADF-contaminated stormwater with glycol concentrations 

greater than 0.5 percent. 

10.2.4.1 Example Cost Calculation 

The following example shows how the Airport Deicing Cost Model uses the equations in 

Section 10.2.2 along with an airport’s questionnaire response to estimate costs. The example 

below is designed to more clearly illustrate the Airport Deicing Cost Model. 

Example Airport Capital and Annual Costs 

Airport A has six deicing outfalls and currently has no collection or control equipment in 

place for ADF-contaminated stormwater. The estimate of airport normalized ADF usage is 

approximately 490,000 gallons per year of Type 1 and Type IV ADF. The airport has 23 deicing 

days per year spanning a five-month period (150 days). The airport does not discharge to a 

POTW or contract haul ADF to an off-site recovery/recycle facility. Based on the final rule, the 

airport will collect 40 percent of the available ADF using a plug and pump system with GCVs. 

Collected ADF contaminated stormwater will be treated by an AFB treatment system. 

Winter Operations Plan Development 

Engineering Labor: 240 hours × $100/hr = $24,000 

Plug and pump Collection System 

Plug and Pump Capital Cost: = 6 × $263,400 = $1,580,400 

Plug and Pump Annual O&M Cost ($/yr) = 6 × $260,000 = $1,560,000/yr 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category Section 10 – Technology Costs 

131 

Table 10-6. Airport Deicing Cost Model Equations, Input Variables, and Assumptions 

Calculation Description Equation Input Variables A

Estimates costs for airports to prepare a one-time winter operations plan as a supplement to the current SWPPP. 

Winter Operations Plan ($) 20% ADF collection: 120 hours × $100/hr 40% ADF collection: 240 hours × $100/hr 

Target ADF collection percentage Labor costs ass

with an outside winter operation

Estimates costs to purchase and operate GCVs to collect 20% of available ADF. Includes a 20% factor on the O&M costs for drainage control. 

GCV Capital Cost ($) = $344,238 × number of GCVs GCV Annual Cost($/yr) = $59,773 × number of GCVs × 1.2 

Airport hub status Small, medium 

require 2 GCVsrequire 3 GCVs 

Estimates costs to install and operate a block-and pump collection system with GCVs to collect 40% of available ADF. 

Plug and Pump Capital Cost ($) = $263,400 × outfall number Plug and Pump Annual Cost ($/yr) = $260,000 × outfall number 

Number of stormwater deicing outfalls from the airport questionnaire 

The number of the number and requiring contro

Estimates costs to install and operate an AFB bioreactor treatment system. 

AFB COD Load (lbs/day) = ADF Use × 14.28 × Collect % / 100 × 1/operating days AFB Unit Capital Cost ($/lb/day): 275,101 × (COD Load)-0.6279

AFB Capital Cost ($): AFB Unit Capital Cost × COD Load AFB Annual Cost ($/yr) = ADF Use × Collect % / 100 × $4.90 

ADF use from airline detailed questionnaire Treatment system operating period based on deicing months from airline detailed questionnaire Collection % from selected collection technology 

Ultimate COD Type I ADF. 

Estimated costs to install storage tanks to equalize collected ADF -contaminated stormwater. 

Storage Tank Capital Cost ($) = ADF Use × 11.4 × $1.67 Storage Tank Annual Cost ($/yr) = ADF Use × $0.27 

ADF use from airline detailed questionnaire 

Storage tank vogal per gal of A
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category Section 10 – Technology Costs 

Table 10-6 (Continued) 

132 

Calculation Description Equation Input Variables A

Estimated costs to install an additional 10,000 linear feet of stormwater piping to convey ADFcontaminated water from collection to treatment. 

Piping Capital Cost ($) = $1,140,000 Piping Annual Cost ($/yr) = $5,600 

None Based on 10,00

diameter subsur

Estimated cost for land to install storage tanks and an AFB treatment system. 

AFB Treatment System Annual Land Cost ($/yr) = $104,544 Storage Tank Annual Land Cost ($/yr) = 1.2 × (ADF Use gal/yr × 13.1 gal/gal/yr × 0.0095 ft2/gal) × $1/ft2

None ADF use from airline detailed questionnaire 

AFB treatment on 2.4 acres and $1/ft2. 

Lease cost for l
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

133

AFB Biological Treatment System 

AFB COD Loading = 490,000 gal/yr × 14.38 lbs COD/gal ADF × 0.4 × 1/150 days/yr = 18,789 

lbs/day 

AFB Unit Capital Cost ($/lb/day): 275,101 × (18,789)-0.6279 = $570/lb COD/day 

AFB Capital Cost ($): 18,789 lbs/day COD × $570/lb COD/day = $10,711,000 

AFB Annual O&M Cost ($/yr): 490,000 × 0.4 × $4.90 = $960,000/yr 

Piping System 

Piping system capital cost: $1,140,000 

Piping system annual O&M cost: $5,600/yr 

Storage Tank(s) 

Storage Tank Capital Cost ($) = 490,000 × 11.4 × $1.67 = $9,329,000 

Storage Tank Annual O&M Cost ($/yr) = 490,000 × $0.27 = $132,300 

Land 

AFB Cost ($/yr) = $104,544 

Storage Tanks ($/yr) = $1.2 × 490,000 gal/yr × 13.1 gal/gal/yr × 0.0095 ft2/gal × $1/ft2 = $60,980

The total capital and O&M costs are therefore: 

Cost Category Capital Costs ($) O&M Costs ($/year) 

Winter Operations Plan 24,000 

Plug and Pump Collection System 1,580,400 1,560,000 

AFB Treatment System 10,711,000 960,000 

Piping 1,140,000 5,600 

Storage 9,329,000 132,300 

Land Opportunity Costs – For AFB Treatment System — 104,544 

Land Opportunity Costs – For Storage — 60,980 

Total 22,784,400 2,823,424 

The capital costs are then amortized and added to the annual O&M costs to assess an overall 

annualized cost for the facility. 

10.2.5 Annualized Costs for ADF Collection and Treatment Alternatives 

Table 10-7 presents the annualized costs by airport developed for the two control and 

treatment scenarios evaluated by EPA for the final rule. See the Economic Development 

document (USEPA, 2012; DCN AD01280) for a more detailed analysis of annualized costs. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

134 

Table 10-7. Annualized Costs by Model Facility for Control and Treatment 1

Airport 

ID Airport 

Current ADF 

Collection 

Annualized Cost for 

20% Control and 

Treatment Scenario 

(2006 $) 

Annualized Cost for 

40% Control and 

Treatment Scenario

(2006 $) 

10012 Montgomery Regional (Dannelly 

Field) 

0 $1,168 $1,168 

10033 Ketchikan International NA $0 $0 

1004 Norfolk International 20 $0 $2,235,548 

1006 Chicago O'Hare International 40 $0 $0 

1007 Yeager 40 $0 $0 

1008 Tucson International 20 $0 $1,069,305 

1010 Fairbanks International ≥60 $0 $0 

1011 Lambert-St Louis International ≥60 $0 $0 

1012 Ted Stevens Anchorage 

International 

40 $0 $0 

1014 Albuquerque International Sunport 20 $0 $6,269,926 

1015 Gulfport-Biloxi International ≥60 $0 $0 

1017 Austin Straubel International 40 $0 $0 

1018 Piedmont Triad International 0 $1,090,753 $8,121,534 

10192 Ontario International 0 $1,110 $1,110 

1020 Hartsfield - Jackson Atlanta 

International 

≥60 $0 $0 

1021 Buffalo Niagara International 40 $0 $0 

1022 Fort Wayne International 0 $991,516 $3,272,310 

1023* Seattle-Tacoma International 0 $1,560,687 $3,863,913 

1024 Indianapolis International 40 $0 $0 

1026 Dallas/Fort Worth International ≥60 $0 $0 

1028 Denver International ≥60 $0 $0 

1029 La Guardia 0 $2,976,443 $6,286,465 

1031 Richmond International 40 $0 $0 

1032 Austin-Bergstrom International 40 $0 $0 

1033 Mc Carran International 40 $4,216 $4,216 

1034 Metropolitan Oakland 

International 

≥60 $0 $0 

1035 San Diego International ≥60 $0 $0 

1036 Baltimore-Washington 

International 

≥60 $0 $0 

1037 George Bush Intercontinental 

Airport/Houston 

40 $4,099 $4,099 

1040 Louis Armstrong New Orleans 

International 

≥60 $0 $0 

1041 Glacier Park International 0 $1,037,252 $1,266,155 

1043 Ralph Wien Memorial 0 $605,365 $707,178 

1044 Roanoke Regional/Woodrum Field 0 $943,332 $4,095,087 

10452 Norman Y. Mineta San Jose 

International 

10 $0 $0 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

Table 10-7 (Continued) 

135

Airport 

ID Airport 

Current ADF 

Collection 

Annualized Cost for 

20% Control and 

Treatment Scenario 

(2006 $) 

Annualized Cost for 

40% Control and 

Treatment Scenario

(2006 $) 

1046 Long Island Mac Arthur ≥60 $0 $0 

1050 Aspen-Pitkin Co/Sardy Field 40 $0 $0 

1052 Wilmington International 0 $654,946 $3,131,737 

1053 General Edward Lawrence Logan 

International 

0 $4,860,377 $6,659,582 

1054 Jackson Hole ≥60 $0 $0 

1057 Will Rogers World 0 $986,385 $2,675,571 

1058 Gerald R. Ford International 40 $0 $0 

1059 Greater Rochester International 50 $0 $0 

1061 William P Hobby ≥60 $0 $0 

10622 Birmingham International 0 $2,675 $2,675 

1063 Evansville Regional 0 $846,931 $1,609,927 

1065 Albany International ≥60 $0 $0 

1066 Salt Lake City International ≥60 $0 $0 

1067 Helena Regional ≥60 $0 $0 

1068 Eppley Airfield 0 $1,250,502 $2,132,279 

1069 Cleveland-Hopkins International 40 $0 $0 

1070 City of Colorado Springs 

Municipal 

40 $0 $0 

1074 South Bend Regional ≥60 $0 $0 

1075 Pensacola Regional ≥60 $0 $0 

1078 Nashville International ≥60 $0 $0 

1079 Manchester 0 $1,600,420 $1,995,084 

1080 Syracuse Hancock International ≥60 $0 $0 

1081 Bob Hope ≥60 $0 $0 

1083 Tampa International ≥60 $0 $0 

1084 Bismarck Municipal 0 $770,509 $1,215,970 

1086 Palm Beach International ≥60 $0 $0 

1087 El Paso International ≥60 $0 $0 

1088 Outagamie County Regional 0 $1,011,102 $2,412,516 

1089 John F Kennedy International 0 $3,215,317 $10,136,241 

1090 Boise Air Terminal/Gowen Fld ≥60 $0 $0 

1091 Rochester International 40 $0 $0 

1094 Boeing Field/King County 

International 

40 $0 $0 

1095 Chicago Midway International ≥60 $0 $0 

10972 Lovell Field 0 $3,745 $3,745 

10992 Sacramento International 20 $0 $0 

1100 Toledo Express 20 $0 $1,767,861 

1101 Portland International 20 $0 $2,792,934 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

Table 10-7 (Continued) 

136

Airport 

ID Airport 

Current ADF 

Collection 

Annualized Cost for 

20% Control and 

Treatment Scenario 

(2006 $) 

Annualized Cost for 

40% Control and 

Treatment Scenario

(2006 $) 

1102 John Wayne Airport-Orange 

County 

≥60 $0 $0 

1103 Juneau International 0 $957,795 $2,343,519 

1104 Nome 0 $618,441 $1,904,296 

1105 Spokane International ≥60 $0 $0 

1107 Pittsburgh International ≥60 $0 $0 

1108 Louisville International-Standiford 

Field 

≥60 $0 $0 

1111 Port Columbus International 0 $2,029,946 $4,321,331 

1113 Cincinnati/Northern Kentucky 

International 

≥60 $0 $0 

1114 Stewart International 40 $0 $0 

1115 Jacksonville International ≥60 $0 $0 

1116 Reno/Tahoe International 20 $0 $1,614,875 

1117 Cherry Capital ≥60 $0 $0 

1118 Bethel 0 $643,331 $1,936,511 

1119 Rickenbacker International 0 $710,969 $1,433,955 

1120 Rapid City Regional 0 $838,073 $4,548,952 

1121 Theodore Francis Green State ≥60 $0 $0 

1122 Southwest Florida International ≥60 $0 $0 

1123 James M Cox Dayton International ≥60 $0 $0 

1124 Des Moines International 40 $0 $0 

1126 Minneapolis/St Paul 

International/Wold-Chamberlain 

≥60 $0 $0 

1128 Charlotte/Douglas International 0 $1,574,890 $2,111,996 

1129 Bradley International ≥60 $0 $0 

1130 San Antonio International 0 $780,240 $5,064,195 

1131 Wilkes-Barre/Scranton 

International 

0 $971,556 $1,476,180 

11332 Phoenix Sky Harbor International 20 $0 $0 

11352 Lafayette Regional 0 $1,536 $1,536 

1136 General Mitchell International 44 $0 $0 

1137 Dallas Love Field 40 $0 $0 

1138 Detroit Metropolitan Wayne 

County 

≥60 $0 $0 

1139 Philadelphia International ≥60 $0 $0 

1140 Memphis International 0 $1,740,377 $3,651,474 

1141 Ronald Reagan Washington 

National 

40 $0 $0 

1142 Washington Dulles International 40 $0 $0 

1143 San Francisco International ≥60 $0 $0 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

Table 10-7 (Continued) 

137

Airport 

ID Airport 

Current ADF 

Collection 

Annualized Cost for 

20% Control and 

Treatment Scenario 

(2006 $) 

Annualized Cost for 

40% Control and 

Treatment Scenario

(2006 $) 

1144 Central Wisconsin 0 $952,550 $1,451,583 

1145 Newark Liberty Intl 0 $5,366,144 $9,674,611 

1146 Northwest Arkansas Regional 0 $873,730 $1,644,615 

1147 Raleigh-Durham Intl 0 $1,294,323 $4,254,332 

1148 Kansas City Intl 40 $0 $0 1 Treatment includes installation and operation of an AFB biological treatment system. 2

 Airport is in a warm climate and uses either no ADF or less than 5,000 gal/yr.; EPA assumes the airport will 

contract out all ADF removal and disposal operations. 

3 Airport was sent an airport questionnaire but did not respond. 

*The airport post-questionnaire has installed deicing pads. High BOD stormwater is sent to a POTW.

10.3 Airfield Deicing Costs

This section describes EPA’s cost evaluation for model airports to discontinue using urea 

as an airfield deicing chemical. Information collected by EPA during the rulemaking effort 

indicated that use of urea as an airfield deicing chemical is being phased out due to concerns 

with its environmental impacts and the availability of less harmful alternatives. Responses to 

EPA’s airport questionnaire indicated that potassium acetate was by far the predominant airfield 

deicing chemical in use from 2002 to 2005, representing about 80 percent of all airfield deicing 

chemical use; therefore, EPA assumed that airports would switch to this chemical to deice their 

pavement. However, approximately 35 of the surveyed airports continued to use urea for airfield 

deicing during the 2002/2003, 2003/2004, and 2004/2005 deicing seasons. EPA did not estimate 

capital or operating costs associated with airfield deicing control for model airports that did not 

report urea usage. 

10.3.1 Urea and Potassium Acetate Chemical Costs and Application Rates 

EPA evaluated the chemical cost of using urea compared to the chemical cost to use 

potassium acetate in evaluating costs for controlling discharges associated with pavement 

deicing. This section presents information on the chemical, mechanical, and storage costs to 

replace urea with potassium acetate. Additional details on urea and potassium acetate use is 

included in a memorandum entitled Estimated Costs for Transition to Liquid Airfield Deicing 

Application from Solid Airfield Deicing (ERG, 2010a). 

Based on responses to the airport questionnaire (USEPA. 2006b), 19 of the airports that 

used urea also used potassium acetate. EPA attempted to contact these airports to obtain their 

unit costs for both chemicals and were able to get unit cost data from eight of these airports. 

Table 10-8 presents the average cost for urea and potassium acetate during the 2002-2005 time 

frame for these eight airports. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

138

Table 10-8. Average Cost for Urea and Potassium Acetate, 2002-2005 

Year Average Urea Cost Average Liquid Potassium Acetate Cost

2002 $268.17/ton $2.81/gallon 

2003 $280.57/ton $2.86/gallon 

2004 $297.90/ton $2.86/gallon 

2005 $300.21/ton $2.92/gallon 

Potassium acetate is applied at different rates depending on the weather conditions and 

the thickness of the ice layer at the time of application. Table 10-9 shows the typical deicing, 

anti-icing, and prewetting application rates for four commercial potassium acetate runway 

deicers. 

Table 10-9. Typical Application Rates for Potassium Acetate 

Brand Name Deicing Application Rates 

Anti-Icing 

Application Rates Prewetting Application Rates 

Safeway® KA Runway 

Deicing Fluid 

1 gal/1000 ft2 0.4gal/1000ft2 70% solid and 30% liquid 

Cryotech E-36® LRD 1 gal/1000 ft2 (thin ice) and 

3 gal/1000 ft2

 (2.5cm thick 

ice) 

0.5 gal/1000ft2 85-95% solid and 5-15% liquid, 

or 130g/kg of solid deicer, 

1.25gal/100lbs. solid deicer 

IceClear RDF 1 gal/1000 ft2 (thin ice) and 

3 gal/1000 ft2

 (1in. thick ice) 

0.5 gal/1000ft2

PEAK® PA 1 gal/1000 ft2 0.4 gal/1000ft2 70% solid and 30% liquid 

Although it could not obtain actual application rates for urea at individual airports, EPA 

did obtain airfield application rates for sodium acetate; therefore, the Agency used sodium 

acetate rates as a surrogate to estimate urea application rates. The amount of sodium acetate 

required to provide the same protection as urea is between 66 and 70 percent (Transport Canada, 

1998). EPA used this relationship to calculate the corresponding urea application rates. Table 

10-10 lists typical application rates for Cryotech NAAC®, a commercial sodium acetate deicer 

and the corresponding urea application rate based on the relationship between sodium acetate 

and urea. 

Table 10-10. Application Rates for Sodium Acetate and Urea 

Sodium Acetate, Cryotech NAAC®, Application 

Rate Urea Application Rate 

Near 32°F on thin ice = 3-5 lbs/1000 ft2 Near 32°F on thin ice = 4.3-7.1 lbs/1000 ft2

Less than 10°F on 1 inch ice = 10-25 lbs/1000 ft2 Less than 10°Fb on 1 inch ice = 14.3-35.7 lbs/1000 ft2

Using the information in Table 10-10, EPA estimated the application costs for urea and 

potassium acetate based on the 2005 average unit costs ($/1,000 ft2), as shown in Table 10-11. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

139

Table 10-11. Cost for Application of Urea and Potassium Acetate, per 1000 Square Feet 

Chemical 

Deicing Application Cost 

(per 1000 ft2) 

Anti-Icing 

Application Cost 

(per 1000 ft2) 

Urea $0.65-$1.07, Near 32°F on thin ice 

Potassium Acetate $2.92 (thin ice) and $8.76 (thick ice) $1.17-$1.46 

10.3.2 Mechanical Application Equipment and Storage of Potassium Acetate 

Airports that change from urea to potassium acetate for airfield deicing will need new 

application equipment to apply a liquid rather than a solid as well as liquid storage tanks to 

contain potassium acetate during the deicing season. The following sections discuss the costs for 

mechanical application equipment and storage tanks for liquid potassium acetate. 

10.3.2.1 Mechanical Application Equipment 

Airports require application equipment to spread chemical deicers on the airside 

pavement. A change from solid to liquid chemicals will require an airport to purchase or retrofit 

equipment to properly apply liquid chemical deicers. EPA requested liquid chemical application 

equipment costs from vendors across the country that offer a variety of different application 

equipment options and obtained costs from three vendors. EPA requested information on 

equipment of various sizes to assess costs by a large vs. small/medium coverage area. 

Based on information provided by the vendors, EPA assumed that new trucks with a 

large coverage area operated with 100-foot spraying booms and at least 2,500 gallons of tank 

space. For truck retrofits or trailers, EPA assumed a large coverage area for units that operated 

with at least 75-foot booms and at least 2,000 gallons of tank space. EPA assumed that new 

trucks with a small/medium coverage area operated with 50-foot spraying booms and at least 

1,100 gallons of tank space. For truck retrofits or trailers, EPA assumed a small/medium 

coverage area for units that operated with booms of 50 feet or a different type of spreading 

mechanism. EPA used this information to estimate liquid application equipment costs for those 

airports that currently use solid urea. 

Table 10-12 provides costing information for small/medium and large liquid deicer 

application equipment. Equipment is presented for two types of installations: new sprayer trucks 

and truck retrofits/towed sprayers. Costs are presented as a total capital cost and are averaged by 

equipment type and size. 

EPA assumed that small, medium, and Non-hub airports would be required to purchase a 

medium-size spreader truck and a medium-size truck retrofitted with a tow unit for application of 

potassium acetate. EPA assumed Large Hub airports would purchase a large-size spreader truck 

and a large-size truck retrofitted with a towed unit. Based on these equipment assumptions and 

the relationship between urea and potassium acetate amounts, EPA estimated small, medium and 

Non-hub airports would be required to spend approximately $203,000 for a potassium acetate 

application system and large airports would be required to spend approximately $348,000. EPA 

assumed that airports using both urea and potassium acetate have sufficient application 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

140

equipment available to apply only potassium acetate and those airports were not assigned 

application equipment costs. 

10.3.2.1 Potassium Acetate Storage Tanks 

Users of liquid pavement deicers can purchase the chemicals in various size carboys or in 

bulk. The actual size of bulk liquid storage tanks needed will depend primarily on the amount of 

deicing chemical purchased each deicing season. EPA used tank cost data from fact sheets 

contained in ARCP Report 14 (ARCP Fact Sheets) to estimate liquid pavement deicer storage 

costs for airports that currently use solid urea for airfield deicing and would need to convert to a 

non-urea-containing deicing chemical. 

Table 10-12. Application Equipment Costs for Liquid Pavement Deicer 

Installation 

Type 

Large 

Coverage Deicing Unit 

Medium/Small 

Coverage Deicing Unit 

Full Truck $160,000 Tyler Ice AD Series – 4,000 

Gallons with 100' Booms 

(Eagle)

$130,000 Tyler Ice AD Series – 2,000 

Gallons with 75' Booms (Eagle)

$280,000 4,000-5,000-gallon units 

(Tyler ICE)

$197,500 2,000-3,000-gallon unit (Tyler 

ICE) 

$245,000 ASP nozzle sprayer spraying 

width 45 Meter. Tank content 

10,000 liter (Schmidt)

Average Cost 1 $228,000 $163,000 

Installation 

Type 

Large 

Coverage Deicing Unit 

Medium/Small 

Coverage Deicing Unit 

Truck Retrofit/ 

Spreader 

$110,000 3,500 2T 5M Towed 

Spreader (Eagle) 

$35,000 Smart Tote 125, 8-25' spray 

width (Eagle) 

$35,000 Epoke PC Compact , Drop 

behind spreader (Eagle) 

$130,000 Tyler Ice TAD Series, 2,000 

gallons with 75' booms 

(Eagle) 

$60,000 Tyler Ice TAD Series, 500 

gallons with 12-36' boomless 

spray (Eagle) 

$20,500 Small Tote Sprayer, 8-50' 

booms (Tyler ICE) 

$50,000 ASPT nozzle sprayer spraying 

width of 15 meters. Tank 

content 3,000 liters (Schmidt) 

Average Cost 1 $120,000 $40,000 

1 – Yearly cost was calculated assuming a 6% interest rate and a 20 year loan term. 

Sources: 

Eagle – Mr. Trevor Winn, CA, CFO at Eagle Airfield (a division of Team Eagle Ltd). http://www.team-eagle.ca/. 

Tyler ICE Div. of Wausau Equipment – Mr. Mark Kreutzfeldt. http://www.wausau-everest.com/ 

Schmidt – Mr. Rene Wender - Product Manager Airport equipment. http://www.aebi-schmidt.com. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

141

Table 10-13 provides capital costs for potassium acetate storage tanks. Costs for three 

types of storage tanks are presented: portable (frac), modular, and permanent. For smaller storage 

needs, EPA assumed that an airport could use the chemical tote provided with the liquid deicer 

purchase. EPA assumed that O&M costs for liquid storage are about the same as those for solid 

storage. EPA assumes that a modular tank with a 50,000-gallon storage capacity will be the best 

option for airports that use between 1,000 and 50,000 gallons of liquid airfield deicing chemical 

each deicing season. A modular tank with a 100,000-gallon storage capacity will be the best 

option for airports that use greater than 50,000 gallons of deicing chemical each season. EPA 

assumed that airports using both urea and potassium acetate have sufficient liquid storage 

available and therefore no costs for tanks are assigned to these airports. 

Table 10-13. Storage Tank Capital Costs for Liquid Pavement Deicer 

Tank Type Size (gallon) Transaction Type Cost Cost for 2/3 of a year rental

Portable (Frac) 21,000 Rental $45/day $10,980 

Portable (Frac) 21,000 Rental $1,350/month $10,800 

Average Portable (Frac) Tank Cost $10,890/yr 

Tank Type Size (gallon) Transaction Type Cost Cost per gallon 

Modular 50,000 Purchase $40,000 $0.80 

Modular 100,000 Purchase $50,000 $0.50 

Modular 245,000 Purchase $80,000 $0.33 

Modular 500,000 Purchase $130,000 $0.26 

Modular 1,000,000 Purchase $225,000 $0.23 

Modular 2,000,000 Purchase $375,000 $0.19 

Average Modular Tank Cost $0.38 

Tank Type Size (gallon) Transaction Type Average Cost Cost per gallon 

Permanent 2,000,000 Purchase 2,000,000 $0.90 

Permanent 4,000,000 Purchase 4,000,000 $0.70 

Average Permanent Tank Cost $0.80 

The national average use of urea, based on EPA’s airport questionnaire (U.S. EPA, 

2006b) data for the three deicing seasons between 2002 and 2005, was 7,075,900 pounds per 

year. Using the available range of application rates (small coverage area and large coverage area 

for the same amount of urea) and statistical airport weighting values as determined by EPA, the 

Agency estimated both capital costs for equipment (application equipment and storage tanks) and 

chemical costs for a national switch from urea to potassium acetate. Table 10-14 lists the 

annualized capital costs for application equipment and storage plus the annual cost for potassium 

acetate for those airports in the scope of the final rule that indicated they use urea. Note that 

airports that currently use potassium acetate for a portion of airfield deicing are assumed to have 

both application equipment and storage available and therefore no capital costs are required. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

142

Table 10-14. Annualized Costs for In-Scope Airports to Change from Urea to Potassium 

Acetate for Airfield Deicing 

Airport ID 

Annualized Capital 

Equipment Cost 1 

($/yr 2006) 

Predicted Potassium Acetate 

Annual Cost 

($/yr 2006) 

Total Annualized Cost 

($/yr 2006) 

1007 $30,654 $10,487 $41,141 

1010 $0 $150,844 $150,844 

1012 $0 $657,442 $657,442 

1017 $0 $16,346 $16,346 

1018 $0 $38,826 $38,826 

1022 $0 $105,445 $105,445 

1041 $27,125 $131 $27,256 

1043 $0 $3,935 $3,935 

1053 $49,879 $2,243 $52,122 

1066 $0 $577,406 $577,406 

1074 $30,654 $12,765 $43,419 

1079 $0 $8,854 $8,854 

1090 $0 $159,636 $159,636 

1103 $31,536 $199,901 $231,436 

1105 $31,536 $251,319 $282,855 

1114 $0 $59,734 $59,734 

1116 $0 $2,848 $2,848 

1118 $30,654 $25,971 $56,625 

1128 $0 $91,667 $91,667 

1129 $0 $6,590 $6,590 

1141 $0 $24,660 $24,660 

1144 $0 $33,209 $33,209 

1146 $30,654 $10,625 $41,278 

1147 $30,654 $35,153 $65,807 

1

 Cost includes both application equipment and storage tanks. 

10.4 Other ADF-Compliance-Related Costs

In addition to the costs associated with ADF stormwater collection and control and 

airfield deicing chemical substitution, EPA also analyzed potential monitoring and reporting 

costs for airports to comply with the various options. Specifically, EPA costed the model airports 

to: 

• Assess ADF usage (in some instances, EPA assumed that the airport would not 

need to assess usage); 

• Perform an engineering review of airport operations to determine and document 

compliance with the percent ADF collection standard (for those that are in scope 

of the analyzed collection requirements); 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

143

• Perform annual ADF collection equipment/system inspections(for those who are 

in scope of the analyzed collection requirements); and 

• Perform COD monitoring from an on-site treatment system (such as AFB 

treatment) to demonstrate compliance with the COD standards (for those facilities 

that are in scope of the analyzed option). 

EPA’s assumptions and methodology for estimating these costs are described below 

along with a summary of the in-scope airports which EPA projected would incur these costs. 

Table 10-15 presents these other compliance-related costs for each of the model airports 

determined to be in the scope of the final rule. 

10.4.1 Assessing ADF Usage from Airport Tenants 

EPA assumed that many airports using ADF during typical winter seasons will need to 

collect and compile ADF usage information from the airlines operating at the airport. EPA is 

assuming that airport personnel will collect ADF usage data monthly from airport tenants and 

will collate that data into a spreadsheet, which can be totaled each season to assess an annual 

ADF usage for the entire airport. EPA is assuming that this activity will require 8 hours per 

month and that ADF usage data is collected for 6 months of the year on average (based on 

airports’ reported deicing months). Costs associated with assessing ADF usage will therefore be: 

 8 hours/month × 6 deicing months/year × $35/hour labor rate = $1,680/year 

The labor rate shown in the equation above is based on an average reported labor rate of 

$33/hour obtained from responses to the airport questionnaire and an escalation rate of 7 percent 

to adjust costs to a 2006 basis3

. EPA adjusted the labor rate so that the labor costs for the 

compliance activity will be on a similar-year basis as the other costs assessed by EPA. 

EPA is assuming that only those airports that use less than 80,000 gallons of normalized 

ADF per year would need to collect and assess total airport annual ADF. Rather than collect and 

tabulate ADF usage, airports that use more than 80,000 gallons would likely certify that their 

usage is above the cutoff specified in the analyzed option. 

10.4.2 Determination of ADF Stormwater Collection Percentage 

As part of the options evaluated by EPA in the final rule, airports with normalized ADF 

use of ≥60,000 gallons/year would need to demonstrate that they achieve the analyzed collection 

requirement. Airports would meet the collection requirement using the technologies costed by 

EPA or through other means. EPA is assuming that airports would hire an engineering consultant 

or firm to evaluate the airport’s ADF usage data to calculate its available normalized ADF. The 

engineering consultant would also evaluate information on the airport’s pollution prevention, 

deicing stormwater collection, and on-site treatment or alternative disposal. 

 

3

 From Bureau of Labor Statistics, Producer Price Index industry data for the airport industry. Increase from 2004 to 

2006. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

144 

Table 10-15. Other Compliance-Related Costs by Airport 

Airport ID Airport 

Total Annualized ComplianceRelated Costs 

($/yr 2006) 

1001 Montgomery Rgnl (Dannelly Field) $1,680 

1003 Ketchikan Intl $1,680 

1004 Norfolk Intl $1,680 

1006 Chicago O'Hare Intl $9,279 

1007 Yeager $1,680 

1008 Tucson Intl $1,680 

1010 Fairbanks Intl $9,279 

1011 Lambert-St Louis Intl $9,279 

1012 Ted Stevens Anchorage Intl $9,279 

1014 Albuquerque Intl Sunport $21,333 

1015 Gulfport-Biloxi Intl $1,680 

1017 Austin Straubel International $10,959 

1018 Piedmont Triad International $21,333 

1019 Ontario Intl $1,680 

1020 Hartsfield - Jackson Atlanta Intl $9,279 

1021 Buffalo Niagara Intl $9,279 

1022 Fort Wayne International $1,680 

1023 Seattle-Tacoma Intl $19,653 

1024 Indianapolis Intl $9,279 

1026 Dallas/Fort Worth International $9,279 

1028 Denver Intl $19,653 

1029 La Guardia $19,653 

1031 Richmond Intl $1,680 

1032 Austin-Bergstrom Intl $1,680 

1033 Mc Carran Intl $1,680 

1034 Metropolitan Oakland Intl $1,680 

1035 San Diego Intl $1,680 

1036 Baltimore-Washington Intl $9,279 

1037 George Bush Intercontinental Arpt/Houston $1,680 

1040 Louis Armstrong New Orleans Intl $1,680 

1041 Glacier Park Intl $1,680 

1043 Ralph Wien Memorial $1,680 

1044 Roanoke Regional/Woodrum Field $1,680 

1045 Norman Y. Mineta San Jose International $1,680 

1046 Long Island Mac Arthur $1,680 

1050 Aspen-Pitkin Co/Sardy Field $1,680 

1052 Wilmington Intl $1,680 

1053 General Edward Lawrence Logan Intl $19,653 

1054 Jackson Hole $1,680 

1057 Will Rogers World $1,680 

1058 Gerald R. Ford International $9,279 

1059 Greater Rochester International $9,279 

1061 William P Hobby $1,680 

1062 Birmingham Intl $1,680 

1063 Evansville Regional $1,680 

1065 Albany Intl $19,653 

1066 Salt Lake City Intl $9,279 

1067 Helena Regional $1,680 

1068 Eppley Airfield $19,653 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

Table 10-15 (Continued) 

145

Airport ID Airport 

Total Annualized ComplianceRelated Costs 

($/yr 2006) 

1069 Cleveland-Hopkins Intl $9,279 

1070 City of Colorado Springs Municipal 10,959 

1074 South Bend Regional $1,680 

1075 Pensacola Regional $1,680 

1078 Nashville Intl $19,653 

1079 Manchester $19,653 

1080 Syracuse Hancock Intl $9,279 

1081 Bob Hope $1,680 

1083 Tampa Intl $1,680 

1084 Bismarck Municipal $1,680 

1086 Palm Beach Intl $1,680 

1087 El Paso Intl $1,680 

1088 Outagamie County Regional $1,680 

1089 John F Kennedy Intl $19,653 

1090 Boise Air Terminal/Gowen Fld $10,959 

1091 Rochester International $1,680 

1094 Boeing Field/King County Intl $1,680 

1095 Chicago Midway Intl $9,279 

1097 Lovell Field $1,680 

1099 Sacramento International $1,680 

1100 Toledo Express $1,680 

1101 Portland Intl $19,653 

1102 John Wayne Airport-Orange County $1,680 

1103 Juneau Intl $1,680 

1104 Nome $1,680 

1105 Spokane Intl $10,959 

1107 Pittsburgh International $9,279 

1108 Louisville Intl-Standiford Field $9,279 

1111 Port Columbus Intl $19,653 

1113 Cincinnati/Northern Kentucky International $9,279 

1114 Stewart Intl $1,680 

1115 Jacksonville Intl $1,680 

1116 Reno/Tahoe International $21,333 

1117 Cherry Capital $1,680 

1118 Bethel $1,680 

1119 Rickenbacker International $1,680 

1120 Rapid City Regional $1,680 

1121 Theodore Francis Green State $9,279 

1122 Southwest Florida Intl $1,680 

1123 James M Cox Dayton Intl $9,279 

1124 Des Moines Intl $9,279 

1126 Minneapolis/St Paul Intl/Wold-Chamberlain $9,279 

1128 Charlotte/Douglas Intl $19,653 

1129 Bradley Intl $9,279 

1130 San Antonio Intl $1,680 

1131 Wilkes-Barre/Scranton Intl $1,680 

1133 Phoenix Sky Harbor Intl $1,680 

1135 Lafayette Regional $1,680 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

Table 10-15 (Continued) 

146

Airport ID Airport 

Total Annualized ComplianceRelated Costs 

($/yr 2006) 

1136 General Mitchell International $9,279 

1137 Dallas Love Field $1,680 

1138 Detroit Metropolitan Wayne County $9,279 

1139 Philadelphia Intl $9,279 

1140 Memphis Intl $19,653 

1141 Ronald Reagan Washington National $9,279 

1142 Washington Dulles International $19,653 

1143 San Francisco International $1,680 

1144 Central Wisconsin $1,680 

1145 Newark Liberty Intl $19,653 

1146 Northwest Arkansas Regional $1,680 

1147 Raleigh-Durham Intl $19,653 

1148 Kansas City Intl $9,279 

EPA has estimated 264 hours and $28,424 total costs for a consulting firm to develop and 

document an engineering assessment using airport-specific data. These costs include time for 

project management, data analysis and evaluation of airport drawings, calculation of airportspecific ADF collection, and preparation of a report. EPA developed the project elements and 

estimated the average hourly rate for consulting engineers at $85/hour based on best professional 

judgment. This cost is assumed to occur once each permit cycle (i.e., once every five years). 

EPA assumed that all airports with ≥60,000 gallons/year normalized ADF usage would be 

required to perform this analysis of the airport’s ADF collection percent. 

10.4.3 Annual ADF Collection Equipment/System Inspections 

As part of the options evaluated by EPA for the final rule, airports could document 

annual compliance with the collection standard by demonstrating that their selected BAT system 

was properly maintained and operated. Airports could demonstrate that they were using those 

technologies properly by annually inspecting the collection equipment and documenting that the 

equipment was being maintained and used per the manufacturer’s specifications. 

EPA assumed that an annual inspection of ADF stormwater collection equipment/systems 

would occur prior to the airport’s deicing season and would include the following types of 

activities as applicable: 

• Inspection of GCVs to ensure that they are maintained and ready for use as well 

as any inspection of the vehicle vacuum system recommended by the 

manufacturer (e.g., inspection of the vacuum pressure and/or nozzles); and 

• Inspection of the plug and pump or drainage diversion system to ensure that 

system components are in good condition and working order (e.g., inspection and 

exercising of shut-off values, inspection of balloon inserts). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

147

EPA assumed that 2 weeks of labor (80 hours total) would be required to perform these 

activities on an annual basis: 

80 hours/season × $35/hour labor rate = $2,800/year 

EPA included these costs for all airports with ≥60,000 gallons/year normalized ADF 

usage when evaluating the options with a collection standard in the final rule. 

10.4.4 COD Monitoring of On-Site Treatment Systems 

For this costing effort, EPA assumed that airports requiring additional ADF stormwater 

collection and control to comply with the analyzed options, would treat the stormwater through 

an on-site AFB treatment system. In addition, airports that were already achieving compliance 

with the collection standard that use on-site treatment prior to direct discharge would need to 

monitor compliance with the COD limitation. Most of the airports that currently collect ADFcontaminated stormwater send it to a POTW or to off-site glycol recovery. However, for the 

costing effort, EPA did not assume either POTW discharge or transfer to an off-site glycol 

recovery facility would be a viable option for those airports requiring additional collection and 

control. In assessing national costs, EPA assumed that airports requiring additional collection 

and control would need to conduct ongoing monitoring of the effluent discharge point of the onsite treatment system to ensure permit compliance. 

To estimate AFB discharge monitoring costs, EPA assumed the following: 

• Airports would collect a daily 24-hour composite sample of treatment system 

effluent for analysis of COD for each day the treatment system is operating; 

• Treatment systems would be operated continuously for 26 weeks per year (6 

months); 

• Approximately 1 hour of labor is associated with sample collection and delivery 

of the sample to the laboratory; 

• Labor costs for sample collection are $35/hr;4 and 

• Cost for COD analysis by the laboratory is $22/sample5 and includes the cost of 

the sample container. 

Using the assumptions above, EPA calculated the annual cost for monitoring the effluent 

from an airport treatment system to be $10,374/year as follows: 

• Sample Analysis Cost ($/yr): 1 sample/day × 7 days/wk × 26 wks/yr × 

$22/sample = $4,004; 

• Labor Cost ($/yr): 1 hr/day × 7 days/wk × 26 wks/yr × $35/hr = $6,370; and 

• Total Cost ($/yr): $4,004 + $6,370 = $10,374 

EPA assumed that all model airports with normalized ADF use ≥60,000 gallons/year, 

costed for additional collection and on-site treatment of ADF stormwater would monitor for 

COD at the effluent discharge point from the on-site treatment system. In addition, EPA 

 

4

 Average labor costs from the airport questionnaire escalated to 2006 year basis. 5

 Sample analysis costs obtained from EPA for analysis of COD samples by contract laboratory. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

148

evaluated all of the other model airports estimated as having ≥60,000 gallons/year normalized 

ADF usage to determine which of those airports treat ADF stormwater on site and discharge the 

effluent directly to U.S. surface waters. As a result, EPA also evaluated monitoring costs for the 

following airports: 

• Washington Dulles International Airport; 

• Denver International Airport; 

• Albany International Airport; and 

• Nashville International Airport. 

EPA assumed that all of the other model airports that would be required to meet the 

collection standard do not directly discharge the available ADF required for collection. 

10.5 Summary of Annualized Costs

Table 10-16 summarizes EPA’s annualized costs for ADF collection and treatment, other 

compliance-related costs, and urea substitution costs. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

149 

Table 10-16. Summary of EPA’s Annualized Costs for ADF Collection and Treatment, 

Airfield Deicing Urea Substitution, and Other Compliance-Related Costs 

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Annualized 

Cost for 20% 

Control and 

Treatment 

Scenario 

(2006 $) 

Annualized 

Cost for 40% 

Control and 

Treatment 

Scenario 

(2006 $) 

Total 

Annualized 

ADFComplianceRelated Costs 

($/yr 2006) 

Urea 

Substitution 

Total 

Annualized 

Cost 

($/yr 2006) 

10011 Montgomery Regional 

(Dannelly Field) 

6.7013 $1,168 $1,168 $1,680 $0 

10032 Ketchikan International 1.0000 NC NC $1,680 $0 

1004 Norfolk International 1.0000 $0 $2,235,548 $1,680 $0 

1006 Chicago O'Hare 

International 

1.0000 $0 $0 $9,279 $0 

1007 Yeager 2.1508 $0 $0 $1,680 $41,141 

1008 Tucson International 2.9997 $0 $1,069,305 $1,680 $0 

1010 Fairbanks International 1.0000 $0 $0 $9,279 $150,844 

1011 Lambert-St Louis 

International 

1.0000 $0 $0 $9,279 $0 

1012 Ted Stevens Anchorage 

International 

1.0000 $0 $0 $9,279 $657,442 

1014 Albuquerque International 

Sunport 

1.0000 $0 $6,269,926 $21,333 $0 

1015 Gulfport-Biloxi International 5.8413 $0 $0 $1,680 $0 

1017 Austin Straubel International 2.3269 $0 $0 $10,959 $16,346 

1018 Piedmont Triad International 1.0000 $1,090,753 $8,121,534 $21,333 $38,826 

10191 Ontario International 1.0000 $1,110 $1,110 $1,680 $0 

1020 Hartsfield - Jackson Atlanta 

International 

1.0000 $0 $0 $9,279 $0 

1021 Buffalo Niagara 

International 

1.0000 $0 $0 $9,279 $0 

1022 Fort Wayne International 1.9682 $991,516 $3,272,310 $1,680 $105,445 

1023 Seattle-Tacoma International 1.0000 $1,560,687 $3,863,913 $19,653 $0 

1024 Indianapolis International 1.0000 $0 $0 $9,279 $0 

1026 Dallas/Fort Worth 

International 

1.0000 $0 $0 $9,279 $0 

1028 Denver International 1.0000 $0 $0 $19,653 $0 

1029 La Guardia 1.0000 $2,976,443 $6,286,465 $19,653 $0 

1031 Richmond International 1.0000 $0 $0 $1,680 $0 

1032 Austin-Bergstrom 

International 

1.0000 $0 $0 $1,680 $0 

1033 Mc Carran International 1.0000 $4,216 $4,216 $1,680 $0 

1034 Metropolitan Oakland 

International 

1.0000 NC NC $1,680 $0 

1035 San Diego International 1.0000 NC NC $1,680 $0 

1036 Baltimore-Washington 

International 

1.0000 $0 $0 $9,279 $0 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

Table 10-16 (Continued) 

150

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Annualized 

Cost for 20% 

Control and 

Treatment 

Scenario 

(2006 $) 

Annualized 

Cost for 40% 

Control and 

Treatment 

Scenario 

(2006 $) 

Total 

Annualized 

ADFComplianceRelated Costs 

($/yr 2006) 

Urea 

Substitution 

Total 

Annualized 

Cost 

($/yr 2006) 

1037 George Bush 

Intercontinental 

Airport/Houston 

1.0000 $4,099 $4,099 $1,680 $0 

1040 Louis Armstrong New 

Orleans International 

1.0000 NC NC $1,680 $0 

1041 Glacier Park International 3.1409 $1,037,252 $1,266,155 $1,680 $27,256 

1043 Ralph Wien Memorial 1.0000 $605,365 $707,178 $1,680 $3,935 

1044 Roanoke 

Regional/Woodrum Field 

2.1921 $943,332 $4,095,087 $1,680 $0 

10451 Norman Y. Mineta San Jose 

International 

1.0000 NC NC $1,680 $0 

1046 Long Island Mac Arthur 1.9985 $0 $0 $1,680 $0 

1050 Aspen-Pitkin Co/Sardy Field 4.7500 $0 $0 $1,680 $0 

1052 Wilmington International 6.0388 $654,946 $3,131,737 $1,680 $0 

1053 General Edward Lawrence 

Logan International 

1.0000 $4,860,377 $6,659,582 $19,653 $52,122 

1054 Jackson Hole 4.3500 $0 $0 $1,680 $0 

1057 Will Rogers World 1.0000 $986,385 $2,675,571 $1,680 $0 

1058 Gerald R. Ford International 1.5862 $0 $0 $9,279 $0 

1059 Greater Rochester 

International 

1.0000 $0 $0 $9,279 $0 

1061 William P Hobby 1.0000 $0 $0 $1,680 $0 

10621 Birmingham International 2.8410 $2,675 $2,675 $1,680 $0 

1063 Evansville Regional 5.1042 $846,931 $1,609,927 $1,680 $0 

1065 Albany International 1.0000 $0 $0 $19,653 $0 

1066 Salt Lake City International 1.0000 $0 $0 $9,279 $577,406 

1067 Helena Regional 4.2000 $0 $0 $1,680 $0 

1068 Eppley Airfield 1.0000 $1,250,502 $2,132,279 $19,653 $0 

1069 Cleveland-Hopkins 

International 

1.0000 $0 $0 $9,279 $0 

1070 City of Colorado Springs 

Municipal 

1.7414 $0 $0 10,959 $0 

1074 South Bend Regional 2.1417 $0 $0 $1,680 $43,419 

1075 Pensacola Regional 3.9341 $0 $0 $1,680 $0 

1078 Nashville International 1.0000 $0 $0 $19,653 $0 

1079 Manchester 1.0000 $1,600,420 $1,995,084 $19,653 $8,854 

1080 Syracuse Hancock 

International 

1.0000 $0 $0 $9,279 $0 

1081 Bob Hope 1.0000 NC NC $1,680 $0 

1083 Tampa International 1.0000 NC NC $1,680 $0 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

Table 10-16 (Continued) 

151

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Annualized 

Cost for 20% 

Control and 

Treatment 

Scenario 

(2006 $) 

Annualized 

Cost for 40% 

Control and 

Treatment 

Scenario 

(2006 $) 

Total 

Annualized 

ADFComplianceRelated Costs 

($/yr 2006) 

Urea 

Substitution 

Total 

Annualized 

Cost 

($/yr 2006) 

1084 Bismarck Municipal 3.8679 $770,509 $1,215,970 $1,680 $0 

1086 Palm Beach International 1.0000 $0 $0 $1,680 $0 

1087 El Paso International 3.0457 $0 $0 $1,680 $0 

1088 Outagamie County Regional 2.4841 $1,011,102 $2,412,516 $1,680 $0 

1089 John F Kennedy 

International 

1.0000 $3,215,317 $10,136,241 $19,653 $0 

1090 Boise Air Terminal/Gowen 

Fld 

1.5043 $0 $0 $10,959 $159,636 

1091 Rochester International 3.1749 $0 $0 $1,680 $0 

1094 Boeing Field/King County 

International 

5.8985 $0 $0 $1,680 $0 

1095 Chicago Midway 

International 

1.0000 $0 $0 $9,279 $0 

10971 Lovell Field 4.9996 $3,745 $3,745 $1,680 $0 

10991 Sacramento International 1.0000 NC NC $1,680 $0 

1100 Toledo Express 2.0917 $0 $1,767,861 $1,680 $0 

1101 Portland International 1.0000 $0 $2,792,934 $19,653 $0 

1102 John Wayne Airport-Orange 

County 

1.0000 NC NC $1,680 $0 

1103 Juneau International 1.0000 $957,795 $2,343,519 $1,680 $231,436 

1104 Nome 1.0000 $618,441 $1,904,296 $1,680 $0 

1105 Spokane International 1.5192 $0 $0 $10,959 $282,855 

1107 Pittsburgh International 1.0000 $0 $0 $9,279 $0 

1108 Louisville InternationalStandiford Field 1.0000 $0 $0 $9,279 $0 

1111 Port Columbus International 1.0000 $2,029,946 $4,321,331 $19,653 $0 

1113 Cincinnati/Northern 

Kentucky International 

1.0000 $0 $0 $9,279 $0 

1114 Stewart International 2.8661 $0 $0 $1,680 $59,734 

1115 Jacksonville International 1.0000 $0 $0 $1,680 $0 

1116 Reno/Tahoe International 1.0000 $0 $1,614,875 $21,333 $2,848 

1117 Cherry Capital 3.5400 $0 $0 $1,680 $0 

1118 Bethel 1.0000 $643,331 $1,936,511 $1,680 $56,625 

1119 Rickenbacker International 4.3659 $710,969 $1,433,955 $1,680 $0 

1120 Rapid City Regional 3.1082 $838,073 $4,548,952 $1,680 $0 

1121 Theodore Francis Green 

State 

1.0000 $0 $0 $9,279 $0 

1122 Southwest Florida 

International 

1.0000 $0 $0 $1,680 $0 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

Table 10-16 (Continued) 

152

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Annualized 

Cost for 20% 

Control and 

Treatment 

Scenario 

(2006 $) 

Annualized 

Cost for 40% 

Control and 

Treatment 

Scenario 

(2006 $) 

Total 

Annualized 

ADFComplianceRelated Costs 

($/yr 2006) 

Urea 

Substitution 

Total 

Annualized 

Cost 

($/yr 2006) 

1123 James M Cox Dayton 

International 

1.0000 $0 $0 $9,279 $0 

1124 Des Moines International 1.6211 $0 $0 $9,279 $0 

1126 Minneapolis/St Paul 

International/WoldChamberlain 

1.0000 $0 $0 $9,279 $0 

1128 Charlotte/Douglas 

International 

1.0000 $1,574,890 $2,111,996 $19,653 $91,667 

1129 Bradley International 1.0000 $0 $0 $9,279 $6,590 

1130 San Antonio International 1.0000 $780,240 $5,064,195 $1,680 $0 

1131 Wilkes-Barre/Scranton 

International 

2.6815 $971,556 $1,476,180 $1,680 $0 

11331 Phoenix Sky Harbor 

International 

1.0000 NC NC $1,680 $0 

11351 Lafayette Regional 6.6425 $1,536 $1,536 $1,680 $0 

1136 General Mitchell 

International 

1.0000 $0 $0 $9,279 $0 

1137 Dallas Love Field 1.0000 $0 $0 $1,680 $0 

1138 Detroit Metropolitan Wayne 

County 

1.0000 $0 $0 $9,279 $0 

1139 Philadelphia International 1.0000 $0 $0 $9,279 $0 

1140 Memphis International 1.0000 $1,740,377 $3,651,474 $19,653 $0 

1141 Ronald Reagan Washington 

National 

1.0000 $0 $0 $9,279 $24,660 

1142 Washington Dulles 

International 

1.0000 $0 $0 $19,653 $0 

1143 San Francisco International 1.0000 $0 $0 $1,680 $0 

1144 Central Wisconsin 3.0156 $952,550 $1,451,583 $1,680 $33,209 

1145 Newark Liberty Intl 1.0000 $5,366,144 $9,674,611 $19,653 $0 

1146 Northwest Arkansas 

Regional 

1.8782 $873,730 $1,644,615 $1,680 $41,278 

1147 Raleigh-Durham Intl 1.0000 $1,294,323 $4,254,332 $19,653 $65,807 

1148 Kansas City Intl 1.0000 $0 $0 $9,279 $0 

 NC – Not Calculated. 

1

 Airport is in a warm climate and uses either no ADF or small amounts of ADF, and EPA assumes the airport will 

contract out all ADF removal and disposal operations. 

2

 Airport was sent an airport questionnaire but did not respond. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

153

10.6 References

ACRP Fact Sheets, ACRP Report 14, Deicing Practices, Transportation Research Board, 

Sponsored to Federal Aviation Administration. 

Airport Council International – North America Comments on EPA’s Proposed Effluent 

Limitations Guidelines and New Source Performance Standards for the Airline Industry. 

ERG. 2006. Memorandum from Lou Nadeau and Cal Franz (ERG) to Marla Smith (U.S. EPA). 

Results of Airport Survey Sample Draw. (March 17). DCN AD01234. 

ERG. 2007a. Personnel communication (email) between Mary Willett (ERG) and Roy 

Fuhrmann, Minneapolis/St. Paul International Airport. (May 3). DCN AD00872. 

ERG. 2007b. Personnel communication (email) between Mary Willett (ERG) and Mark Sober, 

Albany International Airport. (May 3). DCN AD00865. 

ERG. 2007c. Personnel communication (email) between Mary Willett (ERG) and Mark Sober, 

Albany International Airport. (June 27). DCN AD00866. 

ERG. 2007d. Personnel communication (email) between Mary Willett (ERG) and Akron-Canton 

International Airport. (May 3). DCNs AD00863 and AD00864. 

ERG. 2008. Memorandum from Cortney Itle and Robyn Reid (ERG) to Airport Deicing 

Administrative Record. Estimated Annual Costs for airports with Limited ADF Use. (February). 

DCN AD01261. 

ERG. 2010. Memorandum from Steve Strackbein and Mary Willett (ERG) to Airport Deicing 

Administrative Record. Estimated Capital and Operation and Maintenance Costs for Glycol 

Collection Vehichle Operation. (October 8). DCN AD01249. 

ERG. 2010a. Memorandum from Steve Strackbein and Mary Willett (ERG) to Brian D’Amico 

and Eric Strassler (U.S. EPA). Estimated Costs for Transition to Liquid Airfield Deicing 

Application from Solid Airfield Deicing. (October 8). DCN AD01252. 

ERG. 2010b. Memorandum from Mary Willett (ERG) to the Airport Deicing Administrative 

Record. Estimated Compliance-Related Costs for the Final Airport Deicing Rulemaking. 

(November 17). DCN AD001255. 

ERG. 2010c. Memorandum from Mark Briggs (ERG) to the Airport Deicing Administrative 

Record. Estimated Capital and O&M Costs for Additional Stormwater Piping. (July 26). DCN 

AD01253. 

ERG. 2010d. Memorandum from Mark Briggs and Mary Willett (ERG) to Airport Deicing 

Administrative Record. Estimated Land Requirements and Opportunity Costs for the Anaerobic 

Fluid Bed Treatment System and ADF Stormwater Storage Tanks. (October). DCN AD01251. 

ERG. 2011. Memorandum from Cortney Itle and Mary Willett (ERG) to Brian D’Amico (U.S. 

EPA). ADF Collection and Control Efficiency Review. (June 15). DCN AD01270. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 10 – Technology Costs 

154

Google Earth Geographical Mapping System, 2007. 

McQueen, R., and Arendt, T. Development of a Deicer Management System for Akron-Canton 

Airport. 

RS Means Construction Cost Data, 68th Annual Edition, 2010. 

Switzenbaum, et al. 1999. Workshop: Best Practices for Airport Deicing Stormwater. DCN 

AD00893. 

Transport Canada, Transportation Development Center. “Laboratory Testing of Tire Friction 

Under Winter Conditions (TP 13392E).” May 1998. 

USEPA. 2006a. Final Engineering Site Visit Report for General Mitchell International Airport, 

Milwaukee, WI. U.S. Environmental Protection Agency. Washington, D.C. (June 7) DCN 

AD00772. 

USEPA. 2006b. Airport Deicing Questionnaire. U.S. Environmental Protection Agency. 

Washington, D.C. DCN AD00354. 

USEPA. 2006c. Final Sampling Episode Report for Albany International Airport. U.S. 

Environmental Protection Agency. Washington, D.C. (July 19). DCN AD00842. 

USEPA. 2010. Airport Deicing Costing Database. U.S. Environmental Protection Agency. 

Washington, D.C. DCN AD01256. 

USEPA. 2012. Economic Analysis for Final Effluent Limitation Guidelines and Standards for the 

Airport Deicing Category. EPA-821-R-12-004. (March). DCN AD01280. 

U.S. Department of Commerce. National Oceanic and Atmospheric Administration (NOAA) 

National Climate Data Center. 

U.S. Federal Aviation Administration (FAA) National Flight Data Center. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 11 – Regulatory Options Considered And Selected For basis Of Final Regulation 

155

11. REGULATORY OPTIONS CONSIDERED AND SELECTED FOR BASIS OF FINAL 

REGULATION

This section presents the technology options evaluated by EPA for the Airport Deicing 

Category as the basis for the final effluent limitation guidelines and standards. It also describes 

the methodology for EPA’s selection of the final technology options. Specifically, this section 

describes the basis for BAT and NSPS; as detailed in this section, EPA is not establishing BPT, 

BCT, PSES or PSNS at this time. 

The regulatory option selected provides the technology basis of the final effluent 

limitation guidelines and standards (ELGs). Entities subject to these regulations would not be 

required to use the specific technologies selected by EPA to establish the ELGs. Rather, an entity 

could choose to use any combination of operational changes, pollution prevention, and treatment 

technologies to comply with the limitations and standards, provided the limitations and standards 

are achieved. 

11.1 BPT and BCT

EPA considered whether in this rule it was necessary to establish BPT limits, given that 

pavement deicers will be controlled at the BAT level. The Agency concluded that it is not 

necessary to promulgate BPT effluent limitation guidelines for the Airport Deicing Category, 

given that the BAT collection and treatment requirements would be at least as stringent as BPT 

requirements. Similarly, EPA is not establishing BCT limitations for this industry because the 

same wastestream that would be controlled by BCT is being controlled by BAT. 

11.2 BAT

For airfield deicing (runways), EPA concludes that the “best available technology” for 

reducing ammonia in wastewater discharges from airfields consists of using deicing products not 

containing urea, instead of those that contain urea. The administrative record for this rulemaking 

shows that products without urea are widely available in the industry, and in fact are already in 

use at a majority of airports across the country. In addition, using only deicers without urea is 

economically achievable by the industry, as explained in the discussion of EPA’s economics 

analysis below. 

To comply with this limitation, a discharger subject to the rule must either certify 

annually that it does not use airfield deicing products that contain urea or airfield pavement 

discharges must achieve a numeric limitation for ammonia as nitrogen of 14.7 mg/L. Table 11-1

presents the in-scope airports impacted by EPA’s BAT standards and EPA’s estimates of costs 

and loading removals associated with the final rule. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 11 – Regulatory Options Considered And Selected For basis Of Final Regulation 

156

Table 11-1. Final Rule BAT Annualized Costs and Load Removals for In-Scope Airports 

Airport 

ID Airport 

Airport 

Weighting 

Factor 

Urea Substitution 

Total Annualized 

Cost 

($/yr 2006) 

Potential 

Load 

Reduction 

(lbs of COD) 

Potential Load 

Reduction 

(lbs of 

Ammonia) 

1007 Yeager 2.1508 $41,141 42,471 15,572 

1010 Fairbanks Intl 1.0000 $150,844 512,432 187,883 

1012 Ted Stevens Anchorage Intl 1.0000 $657,442 3,881,674 1,423,212 

1017 Austin Straubel Intl 2.3269 $16,346 69,240 25,387 

1018 Piedmont Triad Intl 1.0000 $38,826 143,028 52,441 

1022 Fort Wayne Intl 1.9682 $105,445 440,728 161,593 

1041 Glacier Park Intl 3.1409 $27,256 514 189 

1043 Ralph Wien Memorial 1.0000 $3,935 15,435 5,659 

1053 General Edward Lawrence Logan 

Intl 

1.0000 $52,122 15,769 5,782 

1066 Salt Lake City Intl 1.0000 $577,406 1,730,588 634,519 

1074 South Bend Regional 2.1417 $43,419 50,070 18,358 

1079 Manchester 1.0000 $8,854 56,851 20,844 

1090 Boise Air Terminal/Gowen Field 1.5043 $159,636 416,584 152,740 

1103 Juneau Intl 1.0000 $231,436 737,779 270,506 

1105 Spokane Intl 1.5192 $282,855 768,648 281,824 

1114 Stewart Intl 2.8661 $59,734 234,299 85,905 

1116 Reno/Tahoe Intl 1.0000 $2,848 17,265 6,330 

1118 Bethel 1.0000 $56,625 103,927 38,105 

1128 Charlotte/Douglas Intl 1.0000 $91,667 231,340 84,821 

1129 Bradley Intl 1.0000 $6,590 25,849 9,478 

1141 Ronald Reagan Washington 

National 

1.0000 $24,660 120,391 44,141 

1144 Central Wisconsin 3.0156 $33,209 190,526 69,856 

1146 Northwest Arkansas Regional 1.8782 $41,278 27,782 10,186 

1147 Raleigh - Durham Intl 1.0000 $65,807 97,753 35,841 

Source: Airport Deicing Loadings Database (EPA, 2010). 

11.2.1 Airfield Deicing: Product Substitution of Pavement Deicers Containing Urea 

In general, airports discharge airfield pavement deicing chemicals without treatment, due 

to the difficulty and expense of collecting and treating the large volumes of contaminated 

stormwater generated on paved airfield surfaces. EPA is not aware of an available means to 

control these pollutants by collecting and using a conventional, end-of-pipe treatment system. It 

is possible, however, to reduce or eliminate certain pollutants by modifying deicing practices, 

such as using alternative chemical deicing products. In particular, EPA has identified ammonia 

and COD from airfield deicing as pollutants of concern, and both of these pollutants are a byproduct of pavement deicers containing urea. Accordingly, to address discharges of ammonia 

from airfield pavement, EPA identified one candidate for best available technology: product 

substitution, or discontinuing the use of pavement deicers containing urea and using alternative 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 11 – Regulatory Options Considered And Selected For basis Of Final Regulation 

157

pavement deicers instead. EPA found that using deicers without urea is the best available 

technology for reducing discharges of ammonia from pavement deicing because it is safe, 

technologically feasible, and available across the industry. Currently only about 10 percent of 

chemical pavement deicers applied nationwide contain urea. The most widely used pavement 

deicer is potassium acetate, which represents 63 percent of all chemical pavement deicers applied 

nationwide. 

11.2.2 Aircraft Deicing: ADF Collection Requirements and Effluent Limitations 

11.2.2.1 Available ADF Collection Technologies and Scope 

EPA is not aware of an available and economically achievable technology that is capable 

of capturing 100 percent of the sprayed ADF. As described above, the available technologies for 

collecting ADF are glycol collection vehicles, plug and pump equipment, and CDPs. EPA 

estimates these technologies collect 20 percent, 40 percent, and 60 percent of available ADF, 

respectively. 

After considering the comments provided on the proposed regulation and reviewing the 

information in its record, EPA is not establishing a 60 percent ADF collection requirement based 

on CDPs for BAT. First, in response to FAA’s concerns about the exclusive use of deicing pads 

for aircraft deicing, EPA contacted a number of Large Hub airports that currently use CDPs. 

EPA found the current percentage of flights for which these airports use the CDPs ranges from 

50 to 95 percent. The airports explained that various operational or weather-related issues may 

make deicing pad use for all flights cumbersome if not impossible (i.e., severe system-wide 

delays), and require them to deice at the gate in some circumstances. EPA shares the 

commenters’ and FAA’s concerns that moving to exclusive use of CDPs for all deicing might 

lead to operational issues and delays. EPA, in discussions with FAA, attempted to craft 

regulatory provisions to allow an airport limited ability to bypass the use of a centralized pad to 

avoid these circumstances. However, limited data on the site-specific nature of this industry left 

EPA unable to develop regulatory provisions that would give airports the flexibility they need to 

avoid significant operational issues and delays. Second, based on public comments and 

information from FAA, EPA is concerned that some large airports critical to efficient air traffic 

operations in this country are space (land) constrained and that building well-located CDPs for 

all deicing operations at these airports is likely not feasible for that reason. At the time of the 

proposal, EPA estimated that 14 airports would be subject to the 60 percent collection 

requirement. Because the data in EPA’s record indicate that many of these airports currently 

meet this requirement, EPA estimated approximately seven airports would likely need to install 

pads as a result of the proposed requirement. Of these seven airports, four are Large Hubs that, 

over years of expansions and other improvements, have already built out the majority of the land 

available to them. EPA has concluded that the lack of remaining available land, coupled with 

their existing layouts, has left these airports in a position where they cannot construct a CDP that 

conforms to FAA’s Advisory Circulars on deicing pad design (e.g., in a location that aircraft can 

travel to safely and efficiently to conduct deicing operations). 

Therefore, for the final rule, EPA has not established a 60 percent ADF collection 

requirement, which would have been based on identifying centralized deicing facilities as BAT 

for 100 percent of aircraft departures. Because of land constraints and the other reasons 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 11 – Regulatory Options Considered And Selected For basis Of Final Regulation 

158

discussed above, EPA finds that centralized deicing facilities should not be identified as BAT for 

this nationwide rulemaking. 

EPA then considered the other two technologies described in the proposed rule as a 

possible basis of BAT for aircraft deicing discharges for the final rule: 40 percent ADF 

collection requirement based on plug and pump with GCVs and 20 percent ADF collection 

requirement based on GCVs. With either of these collection technologies, as was the case in the 

proposed rule, EPA also included numeric COD limitations for direct discharges of collected 

ADF based on anaerobic treatment. 

11.2.3 Options Considered for Today’s Final Regulation for Identification of BAT for 

ADF Collection and Discharge Requirements 

Using the technology bases identified above for airfield and aircraft deicing discharges, 

EPA developed three primary options for the final rule. All three of these options have the same 

airfield pavement deicing discharge requirements based on product substitution of deicers that do 

not contain urea, but would vary the approach to control aircraft deicing discharges: 

• Option 1: 40 percent ADF collection requirement for large and medium ADF 

users (based on plug and pump with GCVs); numeric COD limitations for direct 

discharges of collected ADF (based on anaerobic treatment); 

• Option 2: 40 percent ADF collection requirement for large ADF users (based on 

plug and pump with GCVs) and 20 percent ADF collection requirement for 

medium ADF users (based on GCVs); numeric COD limitations for direct 

discharges of collected ADF (based on anaerobic treatment); and 

• Option 3: Site-specific aircraft deicing discharge controls: Do not establish 

effluent limitation guidelines in the final rule for aircraft deicing discharges, but 

instead, leave the determination of BAT requirements for each airport to the 

discretion of the permit writer on a case-by-case, “best professional judgment” 

basis based on site-specific conditions. 

Under the first option, in addition to the airfield pavement requirements, all airports that 

use greater than or equal to 60,000 gallons of normalized ADF annually would be required to 

collect 40 percent of available ADF based on plug and pump with GCV technologies. In the 

proposed rule, EPA considered but did not identify this as its lead option because it found its 

costs to be comparable to those of CDPs, while CDPs collect more ADF. In the proposed rule, 

EPA therefore identified CDPs as BAT. Because EPA no longer considers CDPs to be the best 

available technology for existing airports, the plug and pump with GCV option represents the 

technology, among those that remain under consideration for the final rule, that would collect 

the most ADF. 

Under the second option, in addition to the airfield pavement requirements, all airports 

that use greater than or equal to 60,000 gallons of normalized ADF annually but less than 

460,000 gallons of normalized ADF (“medium ADF users,” estimated to be 42 airports) would 

be required to collect 20 percent of available ADF based on GCVs, and airports that use more 

than 460,000 gallons of normalized ADF (“large ADF users,” estimated to be 14 airports) would 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 11 – Regulatory Options Considered And Selected For basis Of Final Regulation 

159

be required to collect 40 percent of available ADF based on the use of plug and pump with GCV 

technology. 

Under both Options 1 and 2, facilities would need to meet numeric effluent limits for 

COD for the collected ADF prior to commingling it with other wastestreams prior to discharge. 

Under the third option, EPA would establish national deicing discharge controls for 

airfield pavement deicing only. BAT limitations for aircraft deicing discharge would continue to 

be established by the permitting authority on a case-by-case basis. 

11.2.4 BAT Options Selection 

EPA is selecting Option 3 as best available technology for controlling airport deicing 

discharges. EPA has determined the best available technology for controlling airfield pavement 

discharges is product substitution. The administrative record for this rulemaking shows that 

products without urea are widely available in the industry, and in fact are already in use at a 

majority of airports across the country. 

With respect to aircraft deicing discharge controls, EPA’s record demonstrates that ADF 

collection and associated treatment technologies are technically feasible for many airports. Data 

supplied from the industry through EPA’s nationally representative survey of airports indicates 

that dozens of airports currently use GCVs and plug and pump collection systems as well as 

myriad pollution prevention technologies and practices, ranging from alternative means of 

applying ADF (e.g., forced air nozzles) to alternate deicing technologies (e.g., infrared deicing). 

Thus, this industry has numerous technology options available for mitigating the pollutants 

associated with aircraft deicing activities. 

However, EPA concludes that none of the ADF collection technologies considered for 

the final rule represents the “best available technology” for the entire category. Rather, EPA 

concludes that best available technology determinations should continue to be made on a sitespecific basis because such determinations appropriately consider local operational constraints 

(e.g., traffic patterns), land availability, safety considerations, and potential impacts to flight 

schedules. Based on the information in its administrative record, EPA cannot identify with 

precision the extent to which such limitations may preclude any particular airports from 

implementing the technologies that it considered for BAT control of aircraft deicing discharges. 

However, the record demonstrates that such limitations exist and are not isolated or insignificant. 

More specifically, comments provided by airport and airline industry on the proposed regulation 

raised concerns about the impacts that ADF collection technologies may have on safety and 

operations at airports across the country. They also commented on the lack of available space at 

many land-constrained airports for ADF collection and treatment technologies. EPA reviewed 

the information submitted in comments, subsequent information provided by industry, and 

information obtained from site visits to thoroughly evaluate these concerns. After reviewing this 

information, EPA agrees with commenters that, while many airports likely are able to implement 

some form of collection or pollution prevention technologies to mitigate pollutant discharges 

associated with aircraft deicing, other airports may not be able to implement specific 

technologies due to space, safety, and operational considerations. This became particularly 

apparent after reviewing questionnaire responses from some of the airports at which EPA also 

conducted site visits. EPA found that its “model facility” approach was not a suitable substitute 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 11 – Regulatory Options Considered And Selected For basis Of Final Regulation 

160

for a detailed analysis of the site constraints at each airport. For example, a permit authority may 

need to evaluate existing traffic patterns at an airport, not only of the aircraft, but also of the 

service vehicles, to determine if additional collection vehicles would lead to unacceptable safety 

concerns. With respect to land constraints, without detailed airport schematics or conducting a 

detailed site visit at each airport, EPA cannot determine if adequate space exists to incorporate 

the specific treatment and collection technologies evaluated as the basis for the final rule. 

Additionally, industry, and FAA in particular, have expressed concerns about possible 

delays and economic impact that could result from using plug and pump and GCVs, both at 

specific airports and nationwide. EPA agrees that delays must be a factor in considering today’s 

possible requirements and recognizes that such delays fundamentally affect U.S and international 

business and recreational interests. 

Airplane deicing activities, by their nature, occur during freezing precipitation events. For 

some airports, even small amounts of precipitation can lead to delayed aircraft departures – even 

without deicing activity and/or ADF collection and treatment. As such, it is difficult to determine 

if delays at an airport during inclement weather are associated with the weather, the ADF 

collection and treatment technologies, or both. Further, even small delays at certain hub airports 

have a ripple effect that can affect the entire national air traffic schedule. 

Some airports have identified procedures to mitigate or prevent delays associated with 

aircraft deicing discharge controls, but these approaches may not be applicable nationwide. 

Further, the extent of delays deemed acceptable is likely to vary by airport. As with land 

constraints, the confounding factors that need to be considered to evaluate possible delays that 

may be associated with the technology bases do not lend themselves to a national determination 

using a model facility approach. Further, EPA does not have detailed site-specific information to 

evaluate delays on an airport-by-airport basis. 

While the facts stated above do not preclude the ability of an airport to collect and treat 

spent ADF, they do illustrate why EPA did not select any of the technologies considered as BAT 

for the final rule, and why a site-specific BAT determination for ADF collection and treatment 

requirements is the proper approach. 

Therefore, for the reasons identified above, EPA determined Option 3 is the only 

technologically feasible and available option considered for today’s final BAT requirements. 

Option 3 would remove 4.4 million pounds of ammonia and 12 million pounds of COD, with a 

projected annual cost of $3.5 million. The costs of Option 3 are reasonable in terms of the 

pollutant reductions achieved ($0.21/lb). Further, as discussed in more detail in the preamble to 

the final rule, EPA finds Option 3 is economically achievable. In addition, EPA examined the 

non-water-quality impacts anticipated from compliance with Option 3 requirements and found 

none or only very minor impacts in comparison to typical industry energy use, emissions 

generation, and sludge generation. Therefore, based on all the factors above, EPA is identifying 

Option 3 as BAT and has based today’s final rule on the Option 3 BAT requirements. 

11.3 NSPS 

For today’s final rule, EPA evaluated “best available demonstrated control technologies” 

for purposes of setting new source performance standards under CWA section 306. Section 306 

directs EPA to promulgate NSPS “for the control of the discharge of pollutants which reflects the 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 11 – Regulatory Options Considered And Selected For basis Of Final Regulation 

161

greatest degree of effluent reduction which the Administrator determines to be achievable 

through application of the best available demonstrated control technology, processes, operating 

methods, or other alternatives, including, where practicable, a standard permitting no discharge 

of pollutants.” Congress envisioned that new treatment systems could meet tighter controls than 

existing sources because of the opportunity to incorporate the most efficient processes and 

treatment systems into the facility design. As a result, NSPS should represent the most stringent 

controls attainable through the application of the best available demonstrated control technology 

for all pollutants (that is, conventional, nonconventional, and priority pollutants). 

After careful consideration of the information in its record, EPA is today promulgating 

the same NSPS requirements for both airfield pavement deicing discharges and airplane deicing 

discharges as it proposed. However, the applicability of the NSPS requirements has changed and 

EPA has revised the new source definition in the rule to mean new airports only and exclude new 

runways at existing airports. EPA determined that, just as with existing sources, all new sources 

would be able to substitute airfield deicing products without urea for those with urea. 

Furthermore, product substitution represents the greatest ammonia level reduction among the 

available technologies considered. Accordingly, EPA identifies product substitution of non-ureacontaining airfield deicers as the best demonstrated available control technology for all new 

sources. As with BAT, there would be two alternatives for meeting this effluent limitation: either 

a certification requirement or a numeric limit on ammonia for all direct discharges of the 

stormwater from the airfields. 

The final rule NSPS also includes a 60 percent collection (based on CDP technology) and 

control requirement for ADF-contaminated stormwater at new airports anticipated to conduct 

significant aircraft deicing activities. EPA, in consultation with FAA, finds that safety, space, 

and operational constraints that may be present at existing airports for the collection and 

treatment technologies discussed in the final rule (CDPs, plug and pump with GCVs, and GCVs 

alone), would not apply to new airports. New airports can be designed to minimize space and 

logistical constraints identified for retrofits at existing airports. Further, among the collection 

technologies for ADF that EPA considered, CDPs collect the greatest level of available ADF. 

Meeting the new source requirements would not be an economic barrier to entry for new airports, 

as the cost of new airport construction, even small airports, is significantly greater than the costs 

associated with collection and/or treatment of spent deicing fluids (see DCN AD01260 for 

further detail). Moreover, according to FAA, when designed properly, CDPs often improve 

traffic flow and reduce delays associated with aircraft deicing. When designing a new airport, the 

local operating agency plans the site for all needed facilities, such as runways, taxiways, 

terminal(s) and other components needed to comply with safety and environmental requirements, 

and this includes deicing facilities. See FAA Advisory Circular 150/5070-6B, “Airport Master 

Plans,” and FAA Advisory Circular 150/5300-14B, “Design of Aircraft Deicing Facilities,” DCN 

AD00852. Finally, EPA notes that it did not receive any negative comments on its proposal to 

base the NSPS ADF collection requirements on CDPs. See DCNs AD01260, AD01284, and 

AD01335for EPA’s rationale for setting NSPS applicability. 

As a point of clarification, EPA is promulgating the same numeric COD limitations for 

collected ADF that is discharged directly from new sources as were proposed. The technology 

basis of the COD limitations, AFB, is available to new airportsand achieves the greatest level of 

pollutant removals of those technologies considered during the development of this regulation. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 11 – Regulatory Options Considered And Selected For basis Of Final Regulation 

162

Further, installing and using this technology is not economically a barrier to entry for new 

airports. 

11.4 PSES and PSNS

EPA is not promulgating PSES and PSNS for the Airport Deicing Category. Although 

some airports in the United States discharge ADF-contaminated stormwater to POTWs, EPA 

received no comments or other information indicating that POTWs currently have problems of 

pollutant pass-through, interference, or sludge contamination stemming from these discharges 

that would necessitate the promulgation of national categorical pretreatment standards. 

Like the biological treatment system that forms the basis for today’s COD limitations, 

POTWs typically use biological treatment systems and are similarly designed to remove organic 

pollutants that contribute to COD and/or BOD5. In general, POTWs can achieve comparable 

removals to the BAT technology basis. However, some airports and POTWs may need to make 

operational adjustments to process the wastewater effectively while avoiding POTW upset. EPA 

received a comment about the Downriver Treatment Facility in Detroit, Michigan, which accepts 

ADF wastewater from the Detroit Metropolitan Wayne County Airport. The treatment plant 

experienced viscous bulking due to a nutrient imbalance that occurred during the months that 

ADF was accepted. The issue was resolved by removing phosphorus at a later stage in the 

treatment plant system, rather than from the raw wastewater. The airport also made significant 

changes to segregate their deicing stormwater, capture and recycle the most concentrated ADFcontaminated stormwater, and control the amount and concentration of stormwater discharged to 

the POTW. 

EPA is aware that high concentration or “slug” discharges of deicing stormwater can 

create POTW upset. The national pretreatment program regulations specifically prohibit 

industrial users from discharging high concentrations of oxygen-demanding pollutants to 

POTWs if they cause interference to the POTW (see 40 CFR 403.5(b)(4)). Under 40 CFR 

403.5(c), control authorities may set and enforce “local limits” for airport discharges to POTWs 

to implement the prohibitions listed in § 403.5(b)(4). This provision ensures that any potential 

limits would protect against POTW interference by the oxygen-demanding pollutants in airport 

deicing discharges. See “Local Limits Development Guidance,” document no. EPA 833-R-04-

002A, July 2004, available on EPA’s website at: 

http://cfpub.epa.gov/npdes/pretreatment/pstandards.cfm. 

 As a result, many airports that discharge to POTWs have airport-specific requirements 

on allowable BOD5 or COD discharge loadings per day to the receiving POTWs. Airports 

usually meet this requirement by storing deicing stormwater in ponds or tanks and metering the 

discharge to meet the POTW permit loading requirements. 

11.5 References

ERG. 2008. Memorandum from Cortney Itle (ERG) to Brian D’Amico (U.S. EPA). Airport 

Deicing Loading Calculations. (April 17). DCN AD01140. 

ERG. 2012. Memorandum from Mary Willett and Cal Franz (ERG) to Brian D’Amico (U.S. 

EPA). NSPS Feasibility – ADF Collection and Treatment Requirements. (January 23). DCN 

AD01284. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 11 – Regulatory Options Considered And Selected For basis Of Final Regulation 

163

USEPA. 2009. Economic Analysis for Proposed Effluent Limitation Guidelines and Standards 

for the Airport Deicing Category. U.S. Environmental Protection Agency. Washington, D.C. 

EPA 821-R-09-005. DCN AD01196. 

USEPA. 2010. Airport Deicing Loadings Database. U.S. Environmental Protection Agency. 

Washington, D.C. DCN AD01257. 

USEPA. 2012. Memorandum from Brian D’Amico (U.S. EPA) to Record. Final Rule Barrier to 

Entry Analysis for New Source Performance Standards for Airport Deicing. (February 8). DCN 

AD01260. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 12 – Non-Water Quality Impacts 

164

12. NON-WATER QUALITY IMPACTS

Sections 304(b) and 306 of the CWA require EPA to consider non-water-quality 

environmental impacts (including energy requirements) associated with effluent limitation 

guidelines and standards. As explained in the preamble to the final rule, EPA evaluated three 

regulatory options for today’s rule. The first two options are based on technologies to control 

aircraft and airfield deicing discharges, while the the third option is based on technology solely 

to control airfield deicing discharges. 

In considering non-water quality environmental impacts, EPA first analyzed the potential 

impact of the Option 1 technologies on energy consumption, air emissions, and solid waste 

generation. Because Option 2 is similar to Option 1, but would result in fewer operational 

changes at a subset of airports and therefore lead to fewer non-water quality impacts than Option 

1, EPA did not analyze non-water quality impacts associated with Option 2. Rather, EPA 

concluded that the results for Option 2 will be similar to or less than Option 1. Additionally, 

Option 3 has no associated non-water quality impacts as substituting one airfield deicing product 

with another causes no increase in energy usage, air emissions, or solid waste generation. 

12.1 Energy Requirements 

EPA estimated that the total incremental electrical usage for Option 1 to pump ADFcontaminated stormwater into storage tanks would be approximately 1.2 million kilowatt hours 

per year (kWh/yr). EPA also developed a relationship between electrical use and COD removal 

by the AFB bioreactors based on information provided by Albany International (ALB) airport. 

Using ALB’s information, EPA estimated the electrical requirement for COD removal for 

Option 1 as approximately 1.3 kWh/lb COD removed. Using this unit rate, EPA estimated total 

electrical requirements to remove COD for Option 1 to be a maximum additional 22 million 

kWh/yr. 

EPA also analyzed fuel use by GCVs collecting ADF-contaminated stormwater. EPA 

used airport questionnaire data for diesel fuel costs for GCVs and then estimated an average 

diesel fuel use based on the unit cost for diesel fuel of $2.07/gal.6

 EPA then estimated annual 

fuel usage per gallon of applied ADF to be 0.08 gal/gal ADF applied. Using this relationship, 

EPA estimated that the total incremental consumption of No. 2 diesel fuel, at all airports subject 

to BAT and installing additional collection equipment, is 354,500 gallons per year. 

Additionally, as EPA assumes that aircraft operations will not be delayed as a result of 

Option 1 and that deicing will occur at the gates, there is no increase in jet fuel consumption 

associated with Option 1. 

Below are the calculations to determine the net energy requirements associated with 

Option 1 of the final rule for the collection and treatment of ADF-contaminated stormwater. 

Detailed calculations regarding net energy consumption for the various collection and treatment 

technologies considered for the rule are provided in a separate memorandum entitled Energy 

Requirements for ADF Contaminated Stormwater Collection and Treatment Alternatives (ERG, 

2008a). 

 

6

 This diesel fuel price was the average reported by the Energy Information Administration (EIA) for the 2004-05 

winter season, the same period that EPA is analyzing for airport deicing activity. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 12 – Non-Water Quality Impacts 

To estimate incremental electrical requirements associated with pumping collected ADF 

to storage tanks, EPA assumed airports would continuously operate three well-pit pumps with 

40-horsepower (hp) electric motors during each deicing day. EPA also conservatively assumed 

that all airports would use pumps rather than allow ADF-impacted stormwater to flow by gravity 

to holding tanks. To estimate electrical use by airport based on the number of deicing days per 

year, EPA developed the following equation: 

yr

days SOFP

day

hr 24

hp

kW 7456.0

pump

HP Electrical Pumping 40pumps 3 ××= ×× (12-1) 

Using the equation above, the total SOFP days for those airports that EPA assumed 

would install additional collection equipment, and a wire-to-water efficiency of approximately 

40 percent (Bower, H., 1978), the total incremental electrical usage to pump ADF-contaminated 

stormwater into storage tanks would be approximately 1.2 million kilowatt hours per year 

(kWh/yr). 

EPA developed another relationship between electrical use and COD removal by the 

AFB bioreactors based on information provided by Albany International (ALB) airport. Using 

ALB’s information, EPA estimated the electrical requirement for COD removal as 

approximately 1.3 kWh/lb COD removed. Using this unit rate, EPA estimated the total electrical 

requirements associated with COD treatment. EPA estimates an additional 22 million kWh/yr 

will be required to remove 16,602,900 total pounds per year of COD as a result of the final rule. 

The national estimated increase in electrical power consumption related to increased 

pumping and AFB treatment is 23.2 million kilowatt hours per year. This represents a very small 

fraction (0.0006 percent), of the electrical energy used annually in the United States, which is 

3,950 billion kWh based on EIA statistics. 

EPA notes that AFB treatment systems also generate biogas that can be used as a source 

of heat when burned in facility boilers or when converted to electricity using technologies such 

as microturbines or fuel cells. EPA did not include microturbine costs in its option-costing 

methodology. However, to estimate the potential electricity that could be generated if all AFB 

treatment systems installed microturbines to generate electricity, EPA developed a relationship 

between biogas generation and COD removal based on data provided by ALB airport. EPA 

estimated the AFB reactors will generate approximately 8 cubic feet of biogas per pound of COD 

removed, and the biogas is approximately 60 percent methane. Because one cubic foot of 

methane provides 100 therms and 1 therm is equivalent to 29.3 kWh when converted to electrical 

energy (U.S. Code, Title 15), EPA was able to predict the potential electrical energy available 

from biogas generated by the AFBs treating ADF-contaminated stormwater (see Table 12-1). 

165
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 12 – Non-Water Quality Impacts 

166

Table 12-1. Potential Electricity Generation from AFB Biogas Generation 

Regulatory 

Scenario 

Total COD 

Removal 

(pounds/yr) 

Potential Biogas 

Generation 

(million ft3/yr) 1

Potential Methane 

Generation 

(million ft3/yr) 2

Potential Electrical 

Generation 

(million kWh/yr) 3

40% ADF Capture 16,602,900 129 77.5 23 

1

Calculation based on 8 cubic feet of biogas per lb COD removed. 

2

Assumes biogas is approximately 60% methane per Metcalf and Eddy Wastewater Engineering and Design 

(Metcalf and Eddy, 1979). 

3

Calculation based on 100 therms per cubic foot of methane and 29.3 kWh per therm. 

Comparing the potential electrical generation from converting biogas to electricity to the 

electrical requirements discussed above indicates that AFB treatment of ADF-contaminated 

stormwater could generate most of the electricity needed to operate the treatment systems. 

Fuel use by GCVs collecting ADF-contaminated stormwater is another incremental 

energy requirement for compliance with Option1. To estimate incremental diesel fuel use by 

GCVs, EPA obtained annual diesel fuel costs for GCVs from the airport questionnaire (U.S. 

EPA, 2006) and then estimated diesel fuel use based on the unit cost for diesel fuel (e.g., $/gal). 

According to questionnaire data, one airport spent $17,600 on diesel fuel to operate GCVs to 

recover ADF-contaminated stormwater during the 2004-2005 deicing season, collecting 

approximately 20 percent of their applied ADF in stormwater. Based on an average diesel fuel 

cost of $2.07 per gallon during the 2004/2005 deicing season (U.S. DOE, 2006), EPA estimates 

this airport burned approximately 8,500 gallons of diesel fuel in GCVs. Based on annual ADF 

use and size, EPA estimated diesel fuel use in GCVs to be 0.08 gal/gal ADF applied. Using this 

relationship, EPA estimated total incremental No. 2 diesel fuel consumption at in-scope airports 

installing additional collection equipment to be 354,500 gallons per year. This volume is a 

conservative estimate because it is based on an airport that currently uses only GCVs to collect 

ADF-contaminated stormwater (e.g., 20 percent ADF collection). If airports install a plug and 

pump system to collect ADF-contaminated stormwater, GCV usage and therefore diesel fuel use 

are expected to be less. 

EPA compared incremental diesel fuel use by GCVs at all airports to diesel fuel use on a 

national basis. According to the EIA, approximately 25.4 million gallons per day of No. 2 diesel 

fuel was consumed in the United States in 2005 (U.S. DOE, 2006). Total annual diesel fuel use 

by GCVs to collect ADF-contaminated stormwater at airports would account for a small fraction, 

0.004 percent, of the annual diesel fuel use on a national level. 

12.2 Air Emissions

Additional air emissions as a result of the final rule can be attributed to added diesel fuel 

combustion by GCVs collecting ADF-contaminated stormwater and from anaerobic treatment of 

ADF. Emissions from these sources are discussed below. 

12.2.1 Emissions from GCV Collection 

As discussed in Section 12.1, EPA conservatively estimated that GCVs collecting ADFcontaminated stormwater at airports will consume an additional 354,500 gallons per year of No. 

2 diesel fuel. To estimate air emissions related to combustion of No. 2 diesel fuel in GCVs’ 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 12 – Non-Water Quality Impacts 

167

internal combustion engines, EPA used published emission factors for internal combustion 

engines (U.S. EPA, 1996 AP-42). The Agency selected emission factors for gasoline and diesel 

industrial engines rather than on-road mobile sources because the emission factors for the 

industrial engines include equipment such as forklifts and industrial sweepers and scrubbers 

(U.S. EPA, 1006 AP-42). To estimate emissions from the GCVs, EPA first converted the 

additional 354,500 gallons of diesel fuel to million British Thermal Units (MMBtu) and then 

applied the appropriate emission factors (U.S. EPA, 1996 AP-42). Table 12-2 shows the 

estimated increase in criteria pollutant emissions associated with the use of GCVs. Additional 

details regarding emissions from GCVs are contained in a memorandum titled Air Emissions 

from Airport Deicing Collection and Treatment Technologies (ERG, 2008b). 

Table 12-2. Estimated Incremental Pollutant Emissions from GCVs 

Criteria Pollutant 

Diesel Fuel 

Consumption in 

GCV Internal 

Combustion Engine 

(gal/yr) 

Diesel Fuel 

Consumption in GCV 

Internal Combustion 

Engine 

(MMBtu/yr) 1

Emission Factor for 

Diesel Fuel 

Combustion in 

Internal Combustion 

Engine (lbs/MMBtu)2

Estimated Annual 

Emissions from 

GCVs Burning Diesel 

Fuel 

(tons/yr) 

Carbon Monoxide 354,500 49,630 0.95 24 

Carbon Dioxide 354,500 49,630 164 4,070 

Nitrogen Oxides 354,500 49,630 4.41 109 

Sulfur Dioxide 354,500 49,630 0.29 7 

PM10 354,500 49,630 0.31 8 

1

Heat content of diesel fuel is approximately 140,000 Btu/gal per Perry’s Chemical Engineers Handbook, 6th 

Edition, Figure 9-4. 

2

Emission factors from EPA Compilation of Emission Factors AP-42. 

PM10 – Particulate matter less than 10 um. 

The annual emissions provided in Table 12-2 indicate that an additional 4,070 tons per 

year of carbon dioxide would be emitted from GCVs combusting additional diesel fuel to comply 

with the regulatory options evaluated in the final rule. Carbon dioxide is the primary greenhouse 

gas attributed to climate change; although 4,070 additional tons per year appears to be 

considerable, the amount is very small relative to other sources. For example, in 2006, industrial 

facilities combusting fossil fuels emitted 948 million tons of CO2 equivalents. An additional 

4,070 tons per year from GCVs is an increase of 0.0004 percent in the overall CO2 emissions 

from all industrial sources (U.S. EPA, 2008). 

Comments provided by industry on the proposed rule correctly indicated that additional 

nitrogen oxides would be emitted by equipment constructing the ADF-contaminated stormwater 

collection systems, the AFB treatment system, and any ancillary systems such as roadways and 

storage tanks. According to comments, the Environmental Assessment for the Portland ADF 

collection and treatment system estimated annual nitrogen oxide emissions at 4.48 tons/yr during 

construction. Construction of the ADF collection and treatment system in Portland was estimated 

to occur over approximately 2.5 years, resulting in total nitrogen oxide emissions of 11.2 tons. 

Based on the number of in-scope airports that would potentially require construction under 

EPA’s Option 1, total construction-related nitrogen oxide emissions will be approximately 168 

tons. In comparison, EPA estimated total nitrogen oxide emissions in the United States at 18.3 

million tons (U.S. EPA, 2005). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 12 – Non-Water Quality Impacts 

168

12.2.2 Emissions from AFB Treatment Systems 

Anaerobic digestion of glycols found in ADF-contaminated stormwater generates biogas 

containing approximately 60 percent methane and 40 percent carbon dioxide. Airports installing 

AFBs to treat ADF-contaminated stormwater are expected to burn a portion of the gas in on-site 

boilers to maintain reactor temperature. The remainder of gas can be either combusted in a 

microturbine for electricity generation or flared. Regardless of the combustion technology, 

nearly all biogas generated by AFBs is converted to carbon dioxide, the primary green house 

gas.Table 12-3 shows biogas generation and potential carbon dioxide emissions from AFB 

treatment systems for the costed collection scenario. 

Table 12-3. Potential Air Emissions from AFB Treatment Systems 

Regulatory Scenario 

Total COD Removal 

(pounds/yr) 

Potential Biogas 

Generation 

(million ft3/yr) 1

Potential Carbon Dioxide 

Generation 

(tons/yr) 2

40% ADF Capture 16,602,900 129 3,730 

1

 Calculation based on 8 cubic feet of biogas per lb COD removed. Biogas is 60% methane and 40% CO2. 2

 Assumes 99.9 percent of biogas is converted to CO2 during combustion. 

Carbon dioxide is the primary greenhouse gas attributed to climate change; although 

3,730 additional tons per year for 40 percent ADF capture appears to be considerable, the 

amount is very small relative to other sources as discussed in 12.2.1. 

12.3 Solid Waste Generation 

AFB bioreactors will generate sludge that will require disposal, likely in an off-site 

landfill. To estimate the potential for annual sludge generation by AFB bioreactors treating ADFcontaminated stormwater under Option 1, EPA first estimated the potential COD removal for the 

collection and treatment scenario and then applied published anaerobic biomass yield 

information (Metcalf & Eddy, 1979) to estimate potential total sludge generation on a national 

basis. The biomass yield calculation, which simply multiplies the COD removal by the yield, is a 

rough method of estimating sludge generation and does not account for other factors such as 

degradation or inorganic material (e.g., AFB media) that may be entrained into the sludge. 

However, this method does provide an order of magnitude estimate of sludge generation that can 

be compared to other types of common biological treatment systems to determine if AFB sludge 

generation would be unusually high at airports treating ADF-contaminated stormwater. 

Table 12-4 shows the total COD removal for the collection and treatment scenario and 

the estimated sludge that would likely require disposal. This sludge is expected to be 

nonhazardous and can be disposed of in a municipal landfill. Detailed calculations showing how 

EPA estimated biomass amounts are provided in a memorandum entitled Estimated Sludge 

Generation from AFBs Treating ADF-Contaminated Stormwater (ERG, 2008c). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 12 – Non-Water Quality Impacts 

169

Table 12-4. Estimated Sludge Generation from AFB Bioreactors Treating ADFContaminated Stormwater 

Regulatory Scenario 

Total COD Removal 

(pounds/yr) 1

Anaerobic Biomass Yield

(lbs biomass/lb COD 

removed) 2

Total Sludge Generation

(dry tons/yr) 

40% ADF Capture 16,602,900 0.03 271 

1 Total COD removal from all AFB bioreactors that may be installed at airports. 2 Biomass yield from Metcalf and Eddy. 

To provide some perspective on the potential total amount of biomass produced annually 

by the AFB biological reactors treating ADF-contaminated stormwater, EPA compared the total 

biomass generation data in Table 12-4 to the national biosolids estimates for all domestic 

wastewater treatment plants throughout the United States. According to EPA’s Municipal and 

Solid Waste Division, approximately 8.2 million dry tons of biosolids will be produced in 2010 

(U.S. EPA, 1999). Using the biosolids generation amount shown in Table 12-4 (271 tons/yr), 

EPA estimates that AFB bioreactors treating ADF-contaminated stormwater would increase 

biosolids generation in the United States by approximately 0.003 percent. 

12.4 Summary

EPA reviewed the potential non-water quality impacts of collection and treatment of 

spent ADF using plug and pump with GCVs combined with an AFB treatment system and 

determined that there was an insignificant increase in energy usage and generation of air 

emissions and solid waste. 

EPA then determined that the other regulatory options under consideration would have 

similarly insignificant impacts because the other regulatory options involve fewer or no GCVs 

and smaller or no treatment system. Based on this evaluation of non-water quality impacts, EPA 

concludes there are no non-water quality impacts associated with today’s final rule. 

12.5 References 

Bouwer, H. 1978. Groundwater Hydrology. McGraw Hill Press. 

ERG. 2008a. Memorandum from Mark Briggs (ERG) to Airport Deicing Administrative Record. 

Energy Requirements for ADF-Contaminated Stormwater Collection and Treatment 

Alternatives. (December) DCN AD01166 

ERG. 2008b. Memorandum from Mark Briggs (ERG) to Airport Deicing Administrative Record. 

Air Emissions from Airport Deicing Collectoin and Treatment Technologies. (December) DCN 

AD01165 

ERG. 2008c. Memorandum from Mark Briggs (ERG) to Airport Deicing Administrative Record. 

Estimated Sludge Generation from AFBs Treating ADF-Contaminated Stormwater. (December) 

DCN AD01164 

Metcalf and Eddy. 1979. Wastewater Engineering, Treatment/Disposal/Reuse, Second Edition. 

McGraw Hill Press. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 12 – Non-Water Quality Impacts 

170

U.S. Code Title 15, Commerce and Trade, Chapter 6. 2007. Weights and Measures and Standard 

Time. (January). 

U.S. DOE. 2006. Department of Energy, Energy Information Administration (EIA), No. 2 Fuel 

Oil All Sales/Deliveries by Prime Supplier. DCN AD00919. 

USEPA. 1996. Compilation of Air Pollutant Emission Factors (AP-42), Fifth Edition, Section 

3.3. U.S. Environmental Protection Agency. Washington, D. C. 

USEPA. 1999. Biosolids Generation, Use and Disposal in the United States. U.S. Environmental 

Protection Agency. Washington, D. C. EPA 530D-R-99-009. 

USEPA. 2005. Summary of Nitrogen Oxides Emissions. U.S. Environmental Protection Agency. 

Available online at http://www.epa.gov/air/emissions/nox.htm#noxnat.

USEPA. 2006. Airport Deicing Questionnaire. U.S. Environmental Protection Agency. 

Washington, D.C. DCN AD00354. 

USEPA. 2008. Inventory of U.S. Greenhouse gas Emissions and Sinks: 1990 – 2006. U.S. 

Environmental Protection Agency. Washington, D. C. (April). EPA 430-R-08-05. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

171

13. LIMITATIONS AND STANDARDS: DATA SELECTION AND CALCULATION

This section describes the data selection and statistical methodology that EPA used to 

calculate the final rule limitations for the Airport Deicing Category. As described in this section, 

the effluent limitations and standards account for variation in treatment performance of the 

model technology. For simplicity, the following discussion refers only to effluent limitation 

guidelines; however, the discussion also applies to new source standards. 

EPA is finalizing limitations for COD and ammonia as nitrogen (the latter as a 

compliance alternative), and Section 13.1 briefly describes the pollutant parameters. Section 13.2 

provides an overview of EPA’s data review and selection process. Section 13.3 describes EPA’s 

data conventions. Sections 13.4 and 13.5 describe the COD and ammonia as nitrogen data 

selected as the basis of the final limitations. Section 13.6 describes the percentile basis and 

calculations used for the limitations. Section 13.7 describes achievability and compliance related 

to the limitations. 

13.1 Selected Pollutant Parameters

As described in Section 6, there are a number of pollutants associated with discharges 

from airport deicing operations. EPA is setting effluent limitations for two pollutant parameters, 

COD and ammonia. This section briefly describes the pollutant parameters and the chemical 

analytical methods used to measure their concentrations. 

13.1.1 COD 

COD is a measure of the total organic matter content of both wastewaters and natural 

waters. Measurement of COD can be used to rapidly recognize deterioration in wastewater 

treatment plant performance and the need for corrective action. EPA evaluated data collected by 

the Albany International Airport in New York and by EPA. The Agency evaluated data for COD 

that was measured using EPA Method 410.4 and Hach 8000, both of which are approved for 

compliance monitoring in 40 CFR Part 136. EPA measured COD using Method 410.4, and 

Albany Airport used Hach 8000. Data from the two methods are directly comparable. 

Method 410.4 is a colorimetric procedure with a measurement range of 3 to 900 mg/L for 

automated procedures and a measurement range of 20 to 900 mg/L for manual procedures. The 

Hach 8000 method is a colorimetric procedure that utilizes a preliminary digestion procedure and 

can be used for various concentration ranges. A user has the option of purchasing three different 

sets of reagents and standards. The first has a measurement range of 0 to 40 mg/L; the second, 0 

to 150 mg/L; and the third, 0 to 1500 mg/L. The industry data had a lower measurement limit of 

2.0 mg/L. 

13.1.2 Ammonia as Nitrogen (Ammonia) 

Ammonia as nitrogen (ammonia) is generated as a by-product of using urea-containing 

products for deicing operations. Ammonia can be directly toxic to fish and other aquatic 

organisms and can reduce ambient dissolved oxygen concentrations in receiving surface waters. 

In the data EPA evaluated, ammonia was measured using Methods 350.1 and 350.2, both of 

which are approved for compliance monitoring in 40 CFR Part 136. Albany Airport supplied 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

172

data that was generated using Method 350.1 (ERG, 2008), and EPA used Method 350.2. Both 

methods produce comparable results. 

Method 350.1 is an automated colorimetric method that uses a continuous flow analytical 

system and has a detection range of 0.01 to 2.0 mg/L. Method 350.2 utilizes either colorimetric, 

titrimetric, or electrode procedures to measure ammonia. Method 350.2 has a lower measurement 

range limit of 0.20 milligrams per liter (mg/L) for the colorimetric and electrode procedures and 

a lower measurement range limit of 1.0 mg/L for the titrimetric procedure. 

13.2 Overview of Data Review and Selection

As described in Sections 13.4 and 13.5, EPA qualitatively reviewed all the available 

influent and effluent data for COD and ammonia. For purposes of limitation development, data 

are defined to be numerical values resulting from laboratory determination of pollutants in 

physical samples collected from influent and effluent wastestreams. A laboratory expresses the 

results of its analysis either numerically or as “not quantitated” for a pollutant in a sample. When 

the result is expressed numerically, the pollutant was quantitated, or more commonly referred to 

as “detected,” in the sample. The definition includes measured values (e.g., 10 mg/L) and values 

reported as being below some level of quantification (e.g., <10mg/L). The latter are often 

referred to as “nondetected” and are usually reported with a “detection limit.” (EPA also uses 

terms such as “quantitation limit” in other documentation.) The definition of “data” excludes 

estimated values and statistical summaries, such as averaged values. 

This section describes EPA’s review of the available data. Section 13.2.1 describes the 

criteria that EPA applied in selecting data for the development of the final limitations. Section 

13.2.2 describes other considerations that were evaluated as part of the data review. 

13.2.1 Data Selection Criteria 

This section describes the criteria that EPA applied in selecting data to use as the basis 

for the final effluent limitations. EPA has used these or similar criteria in developing limitations 

and standards for other industries. EPA uses these criteria to select data that reflect consistently 

good performance of the model technology in treating the industrial wastes under normal 

operating conditions. Model technology is technology that is carefully designed and diligently 

operated. The following paragraphs describe the criteria and modifications specific to the Airport 

Deicing Category. 

One criterion generally requires that the influent and effluent from the treatment 

components represent typical wastewater from the industry, with no incompatible wastewater 

from other sources (e.g., sanitary wastes). By applying this criterion, EPA selects only those 

facilities where the commingled wastewaters did not result in substantial dilution, unequalized 

slug loads that result in frequent upsets and/or overloads, more concentrated wastewaters, or 

wastewaters with different types of pollutants than those generated by the categorical (i.e., 

airport deicing) wastewater. 

A second criterion typically ensures that the pollutants were present in the influent at 

sufficient concentrations to evaluate treatment effectiveness. To evaluate whether the data meet 

this criterion for the final rule, EPA often uses a “long-term average test” for sites where it has 

paired influent and effluent data. EPA has used such comparisons in developing regulations for 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

173

other industries (e.g., the Iron and Steel Category (USEPA, 2002)). The test looks at the influent 

concentrations to ensure a pollutant is present at sufficient concentration to evaluate treatment 

effectiveness. If a pollutant fails the test (i.e., is not present at a treatable concentration), EPA 

excludes the data for that pollutant at that facility from its long-term average and variability 

calculations. In this manner, EPA would ensure that the limitations resulted from treatment and 

not simply the absence or substantial dilution of that pollutant in the wastestream. If industry 

supplies EPA with effluent data, but not the corresponding influent data, EPA may choose to use 

the effluent data without performing a long-term average test provided it determines that the 

pollutant would have been present at consistently treatable concentrations at the facility. This 

approach would satisfy EPA’s objective to include as much data from as many facilities as 

possible in the calculation of limits. 

A third criterion requires that the facility must have the model treatment technology and 

demonstrate consistently diligent operation. The Agency may include facilities with treatment or 

performance that is equivalent to the model technology, but this is rare. EPA generally 

determines whether a facility meets this criterion based upon site visits, ability to comply with its 

existing discharge requirements, discussions with facility management, and/or comparison to 

treatment system performance at other facilities. EPA often contacts facilities to determine 

whether data submitted were representative of normal operating conditions for the facility and 

equipment. Based on this review, EPA typically eliminates facilities that experience repeated 

operating problems with their treatment systems. In addition, EPA typically excludes data when 

the facility has not optimized its treatment. For example, facilities may use the model technology 

as a pretreatment step before sending the wastewater to a POTW and consequently might not 

fully optimize its system. 

A fourth criterion typically requires that the data cannot represent periods of frequent 

unequalized slug loading treatment upsets or shut-down periods7

 because these excursion data do 

not reflect performance that would be expected from well-designed and operated treatment 

systems. Furthermore, it would not be appropriate for the limitations to be based, in part, upon 

data reflecting extreme events that are beyond the control of the facility, because regulatory 

provisions at 40 CFR 122.41(n) would apply to such circumstances. More specifically, after the 

final limitations are incorporated into permits, EPA expects that, when such events occur, the 

facility would abide by the procedural requirements in §122.41(n) to obtain an affirmative 

defense to any potential enforcement action. 

In applying the fourth criterion, EPA evaluates the pollutant concentrations, flow values, 

mass loadings, plant logs, and other available information. As part of this evaluation, EPA 

typically asks the facility about process or treatment conditions that may have caused extreme 

values (high and low). EPA may consequently identify certain time periods and other outliers in 

the data that reflect poor performance by an otherwise well-operated site. 

 

7

 EPA applies this criterion to data from two types of shut-downs. First, treatment systems are sometimes halted to 

control upset conditions. As part of the recovery activities, the facility may pump out wastewater from the 

equipment (e.g., tanks) which contains highly concentrated wastes associated with the upset. Second, the facility 

may shut down its operations for maintenance and other atypical operations. During these periods, the facility may 

still operate its treatment system, but typically discharges effluent associated with atypical influent. For example, the 

influent might include cleaning solvents instead of process wastewater. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

174

EPA also applies the fourth criterion in its review of data corresponding to “start-up” 

periods, an adjustment period that most industries incur only when installing, acclimating, and 

optimizing new treatment systems. During this adjustment period, the concentration values tend 

to be highly variable with occasional extreme values (high and low). After this period, the 

systems should operate at steady state for years with relatively low variability around a long-term 

average. Because start-up conditions typically reflect one-time operating conditions, EPA 

generally excludes such data in developing the limitations. In contrast, EPA expects airports to 

encounter start-up operations at the start of every deicing season because they probably will 

cease treatment operations during warmer months. Because this adjustment period will occur 

every year for the Airport Deicing Category, EPA is including start-up data in the data set used 

as the basis of the limitations. However, through its application of the other three criteria, EPA 

would exclude extreme conditions that do not demonstrate the level of control possible with 

proper operation and control even during start-up periods. 

In part, by retaining start-up data for limitations development, the limitations will be 

achievable because EPA based these limits on typical treatment during the entire season. Once 

the treatment system reaches steady state, EPA expects a typically well-designed and operated 

system to run continuously until the end of the deicing season. 

13.2.2 Other Considerations in Data Selection 

In comments on proposed regulations across a range of industry categories and 

subcategories, industries often suggest that EPA consider additional criteria in selecting data as 

the basis of the limitations. EPA routinely evaluates whether the suggested criteria are relevant 

and should be considered as it develops new regulations. As explained below, EPA also 

considered additionalcriteria for the airport deicing rulemaking, but determined that they were 

not relevant in selecting data as the basis of the final limitations. EPA’s rationale is consistent 

with its findings for other industries. 

Commenters often suggest a criterion related to the size of facilities because of concerns 

about a perceived impact of volume, or flow, of wastewater on treatment performance. In 

considering this issue for the airport deicing industry, EPA concluded that the size of the airport, 

collection technology, and other features by themselves would not affect the performance of the 

treatment system. Instead, the airport size and water flow would determine the size of the 

treatment system, rather than its performance. EPA expects that each airport would build and 

operate a system that is sized appropriately for its volume of wastewater. Because the method of 

treatment is the same regardless of the flow, properly sized systems should all perform in the 

same manner, and achieve the same effluent concentrations. Before reaching this conclusion for 

airport deicing and other industries, EPA reviewed treatment technologies such as biological 

treatment, oil-water separators, dissolved air floatation, and settling tanks. EPA's record supports 

the finding that, for a variety of industrial sectors, well-operated and designed treatment systems 

treat different wastewaters with varying flows to a narrow range of effluent concentrations 

(USEPA, 2010). 

In addition, commenters typically suggest a criterion that would require a minimum 

number of facilities be used as the basis of the limitations. Such suggestions are based upon two 

main concerns. First, commenters are concerned that the limitations do not reflect treatment from 

a range of typical influents, because the concentration levels vary from facility to facility. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

175

Second, commenters are concerned that not all facilities could achieve the same high level of 

performance using the model technology. For the first concern, as part of its evaluation of the 

effect of flow described above, EPA also considered the impact of influent pollutant 

concentrations. EPA found that well-operated and designed treatment systems are capable of 

treating the wastewaters to a narrow range of effluent pollutant concentrations. For the second 

concern, EPA only needs to demonstrate that the model technology can be operated at the level 

of performance on which the limitations are based. EPA’s selection of the model technology 

used at the Albany International airport as the basis of the limitations is appropriate because that 

facility demonstrates that the technology can achieve the levels reflected in the final limitations. 

The CWA authorizes EPA to base BAT/NSPS limitations and standards on 

the performance of a single facility and it is not unusual for EPA to base effluent 

limitations on data from a single facility. For example, in the Organic Chemicals, Plastics and 

Synthetic Fibers (OCPSF) effluent guideline promulgated in 1987, EPA based 38 percent of the 

limitations on the performance of a single facility (USEPA, 1987). Courts have recognized that 

EPA must act on the information it has and need not wait for perfect information(e.g., see BASF 

Wyandotte Corp. v. Costle, 598 F.2d 637, 652-653 (1st Circuit, 1979)). 

13.3 Conventions for Modeling Multiple Data Sets from the Same Facility

This section describes EPA’s conventions for modeling multiple data sets from the same 

facility. Data from a particular facility are sometimes collected at different times, from different 

treatment units, or by different organizations. In such cases where multiple data sets exist for the 

same facility, EPA often statistically models the data as if each data set represents a different 

facility. This section describes conventions applied to the data from the airport deicing industry. 

EPA generally considers data from different time periods to characterize different 

operating conditions due to changes such as management, personnel, and procedures. Because 

EPA expects airports to operate treatment systems only for a limited time each year, it 

considered whether the conditions and performance for each deicing season tend to vary in a 

manner that more appropriately reflects different treatment systems. Because it may better 

capture the variability of airport deicing operations under a range of conditions, EPA has 

calculated the final limitations using all of the data, without regard to season. For informational 

purposes, the data and summaries are presented by season. 

EPA generally uses data from separate treatment units (depending on the rulemaking, 

also called “trains” or “systems”) as if they characterized separate facilities. EPA has determined 

this is appropriate because the units were operated separately. Even if the wastes were generated 

by the same processes or drawn from the same storage pond, EPA considers that the performance 

of each system can vary due to slightly different influents, equipment, and other factors. 

EPA generally considers data from different organizations to characterize different 

collection methods and analytical methods. The different organizations typically are EPA 

sampling teams and the facility’s monitoring crew at the treatment system. EPA often separates 

such data into multiple data sets, to better model the variability consistent with the use of a single 

analytical method and the same collection procedures. Consistent use of a single method and 

procedure is often required by permits and is typical of compliance monitoring. Therefore, the 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

176

Agency generally uses this convention to model typical variability that each facility would 

experience in compliance monitoring activities. EPA then determines which, or all, multiple data 

sources are appropriate choices as the basis of the limitations. 

13.4 COD: Data Selected as Basis of Final Limitations

In establishing the final limitations, EPA reviewed COD data from a treatment plant at 

the Albany International airport, which used the model BAT. (Selection of the model technology 

is described in Section 8 and in the preamble to today’s rule.) EPA collected COD data during a 

sampling episode at Albany International airport and obtained several years of monitoring data 

and other information from the airport. After evaluating these data, EPA determined that the 

Albany data were the only available performance data from the model technology.8

 Thus, all 

other data sets were excluded by applying the third criterion in Section 13.2.1, because they did 

not demonstrate the performance of the model technology. The following sections describe the 

Albany airport and apply the criteria in identifying the specific data points used as the basis of 

the final limitations. 

13.4.1 Albany Treatment System 

EPA based the final limitations for COD upon data from Albany Airport’s treatment 

system. This system consists of two identical units that are consistent with EPA’s model 

technology described in Section 8. The airport diverts stormwater from deicing operations into a 

lagoon. Facility personnel then pump water from the lagoon to one anaerobic unit or the other for 

treatment. The airport generally operates the two treatment systems in parallel, but sometimes 

runs them in series. At the end of each unit, regardless of whether the system is in parallel or 

series, the airport monitors COD concentrations each morning by collecting grab samples to 

evaluate the treatment performance. These locations are labeled as ArprtR-101 and ArprtR-102 

in Figure 13-1. During its five-day sampling episode conducted from February 5-9, 2006, EPA 

measured COD and ammonia concentrations in composite samples collected at a point (labeled 

EPA_SP-2) where the two units combine into a single flow before entering an aerobic polishing 

pond for more treatment. After this step, the airport typically directly discharges waste into 

Shaker Creek, a tributary of the Mohawk River, which has been classified as a New York State 

Class A drinking water stream. As a consequence, the airport is required to meet stringent 

limitations when it discharges directly to the creek. In warmer weather (i.e., when the soil is 50 

degrees or warmer), the airport sometimes uses the treated wastewater for irrigation. In addition, 

the airport is able to discharge to a POTW, although it seldom does. 

 

8

 Akron Canton Airport in Ohio started operating the model technology in mid-November in 2007. When EPA was 

completing its technical analysis of the industry in late spring 2008, the airport’s treatment unit was not operating at 

full capacity. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

Lagoon 

Anaerobic unit #1 

Anaerobic unit #2 

Aerobic 

polish 

ArprtR-102 

(COD) 

AprtR-101 

(COD) 

EPA_SP-2 

(COD, Ammonia) 

Figure 13-1. Simplified Drawing of Albany Airport Treatment System and Sample Points 

As the basis for the final limitations for COD, EPA selected the data at sample points 

ArprtR-101 and ArprtR-102 because each unit is the same as the model treatment system that 

EPA identified in Section 11. The airport has monitored its performance for a relatively long 

time and provided EPA with data from December 1, 1999, through April 10, 2009 (10 deicing 

seasons). Because the influent was highly concentrated, it was not necessary to perform the longterm average test described in Section 13.2.9

 

DCN AD01181 provides the influent and effluent COD data as originally submitted by 

the airport and the data are graphically displayed in the statistical support memorandum 

(USEPA, 2006). The following sections describe the exclusion of data collected from the EPA 

sampling episode and the airport’s self-monitoring data. 

13.4.2 COD Data from EPA Sampling Episode at Albany 

During EPA’s sampling episode, EPA and the airport collected separate sets of samples 

(see Table 13-1 analytical results). At sample point EPA_SP-2, EPA collected samples of the 

combined flow from the two units. In contrast, the airport monitored the effluent directly from 

each unit at sample points ArptR-101 and ArptR-102 and filtered the samples prior to analyzing 

for COD. Both sets of samples demonstrate the performance of the model technology because no 

additional treatment steps exist between the airport sample points and EPA’s sample point. 

Rather than include data from two different sources (i.e., EPA and the airport) for the same dates, 

EPA preferentially selected the airport data because they were part of longer-term monitoring. 

Although the EPA data were therefore excluded as the basis of the limitations, EPA notes that all 

of the values are less than the value of 271 mg/L for the final daily maximum limitation. 

 

9

 EPA typically compares average influent levels to a multiplier of 5 to 10 times the quantitation limit (or reporting 

limit). As explained in Section 13.1.1, the airport data had a lower measurement limit of 2.0 mg/L. Thus, in the longterm average test, EPA would probably have compared the influent data to a reference level of 10 to 20 mg/L. 

However, because the minimum influent value of 100 mg/L exceeded this range of potential reference values, the 

average values also will meet the requirements of the long term average test. 

177
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

178

Table 13-1. COD: EPA and Albany Airport Self-Monitoring Effluent Data Collected 

During EPA’s Sampling Episode 

Sample Date 

COD Concentrations (mg/L) 

EPA Sampling Episode Data Airport Self-Monitoring Data 

Original Sample 

Field Duplicate 

(where collected) AprtR-101 AprtR-102 

2/5/06 72 29 74 

2/6/06 228 208 53 108 

2/7/06 92 177 56 94 

2/8/06 81 31 90 

2/9/06 193 48 96 

13.4.3 COD Self-Monitoring Data from Albany Airport 

The airport typically runs the two units in parallel. EPA considers each unit’s 

performance, when operated in this manner, to be consistent with the model technology. In its 

evaluation of the data from each unit, EPA applied the criteria and other considerations described 

in Section 13.2. As a result of this evaluation, EPA excluded data associated with atypical 

operations, influent concentrations reported as zero, estimated values, and poor performance. 

The exclusions are described below. 

By applying the third criterion in Section 13.2.1, EPA excluded all periods when the units 

were operated in series because the data did not reflect treatment by the model technology. Table 

13-2 identifies these time periods by deicing season (e.g., Season99 started in 1999 and 

continued into 2000). During these periods, one unit provided initial treatment and the second 

provided additional treatment. Although the facility reported effluent values from each unit 

during this period of operating in series, it only discharged the effluent from the second unit in 

the series. EPA considers the effluent data from the first unit to reflect less than optimal 

performance, because the operators presumably would have not optimized treatment as they 

intended to treat the wastes a second time (criterion 3). EPA considers the effluent data from the 

second unit to characterize treatment of atypical influent (i.e., effluent that had been treated by 

the first unit). 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

179

Table 13-2. COD: Dates Excluded Because Units Operated in Series 

Season Number Days Excluded Beginning Date End Date 

Season99 32 2/9/2000 3/11/2000 

Season00 31 12/12/2000 1/11/2001 

Season01 3 2/7/2002 2/9/2002 

Season02 8 11/17/2002 11/24/2002 

3 4/5/2003 4/7/2003 

Season05 25 1/10/2006 2/3/2006 

Season06 79 1/15/2007 4/3/2007 

Season07 31 2/2/2008 3/3/2008 

Season08 25 11/17/2008 12/11/2008 

EPA excluded effluent values for both units when the influent concentration was reported 

as “zero” for two reasons. First, if COD could not be detected in the influent (criterion 2), then 

the effluent concentrations would not reflect any additional treatment. Second, it appears that the 

plant used this convention to indicate shut-downs of the system (criterion 4). Table 13-3

identifies the dates when the influent concentration was reported to be zero. 

Table 13-3. COD: Dates Excluded Because Influent Concentration Reported as Zero 

Season Date 

Season01 6/14/2002

Season02 11/16/2002

Season06 4/10/2007

EPA also excluded any values that were estimates because they did not meet EPA’s 

definition for “data” described in Section 13.2. There were two types of estimated values. One 

type was in italics in the facility’s spreadsheets, indicating that the operator’s log noted issues 

with the sample or its analysis, and thus, the reported value was an estimate. The second type 

was a series of identical values reported over consecutive monitoring days. Although it is 

possible to find exactly the same pollutant concentrations on consecutive days, variations from 

day to day are more typical. In response to EPA’s questions about the strings of identical values, 

the facility stated that it sometimes repeated the last known number when they did not monitor 

(ERG. 2008a). To model the variability likely to be present in the effluent, EPA assumed that the 

first non-zero value was the only day when COD was monitored when three or more days had 

identical values for the same unit. Therefore, EPA retained the value for the first day and deleted 

the (identical) values on subsequent days for that unit. If the values were zero, EPA assumed that 

the unit was not operating and excluded the entire time period, including the first reported zero 

value. The statistical support memorandum (USEPA, 2010) identifies these exclusions. 

In addition, by applying the fourth criterion in Section 13.2, EPA excluded periods that 

did not reflect the typical performance of the technology. As shown in Table 13-4, these 

exclusions included treatment system upsets and method error. For example, EPA excluded the 

maximum value of 1,283 mg/L recorded at ArprtR-101 on 3/21/2001 because it was inconsistent 

with the other data values during that time period. The plant management agrees that the value 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

180

does not reflect normal operations and suspects that it was likely a sample with high solids 

content (ERG. 2008b). 

Table 13-4. COD: Dates Excluded Because of Performance Excursions 

Season Number Days Excluded Beginning Date End Date Reason 

Season99 11 12/1/2000 12/11/2000 System Upset 

Season00 42 1/12/2001 2/22/2001 System Upset 

1 3/20/2001 3/20/2001 Method Error 

1 3/21/2001 3/21/2001 System Upset 

After the exclusions were incorporated, more than 2,500 measurements of COD remained 

and were used as the basis of the final limitations. Table 13-5 summarizes the data. The 

statistical support memorandum (USEPA, 2010) provides a list and plots of the data. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

181

Table 13-5. COD: Summary of Albany Airport Self-Monitoring Effluent Data After 

Exclusions 

Unit Season 

COD Concentrations (mg/L) 1

# of 

Days 

Standard 

Deviation Minimum Maximum Median Mean 2

ArprtR_101 

Season99 147 50.31 1 326 14.0 28.60 

Season00 112 71.93 2 575 64.0 75.46 

Season01 168 20.97 9 157 37.0 44.02 

Season02 180 64.41 20 655 73.0 86.80 

Season03 146 103.19 2 699 50.0 76.32 

Season04 140 30.76 2 275 25.0 31.51 

Season05 90 18.08 8 162 29.5 31.56 

Season06 62 24.08 1 136 17.0 23.10 

Season07 124 98.07 9 1042 41.5 54.48 

Season08 120 59.85 15 674 35.0 42.74 

ALL 1289 66.67 1 1042 37.0 52.28 

ArprtR_102 

Season99 141 17.41 1 93 11.0 16.85 

Season00 117 51.50 11 393 55.0 63.09 

Season01 165 20.23 10 168 35.0 40.01 

Season02 183 51.73 25 685 51.0 57.61 

Season03 147 30.03 1 210 60.0 63.12 

Season04 145 73.96 2 725 76.0 87.42 

Season05 95 33.21 22 275 72.0 77.19 

Season06 62 41.68 2 148 46.5 61.34 

Season07 98 10.01 12 58 34.0 33.70 

Season08 120 24.92 12 282 37.0 39.07 

ALL 1273 45.65 1 725 45.0 53.40 

1

 In this summary, nondetected values are set equal to the detection limit. 

2 The mean is calculated as the arithmetic average. 

13.5 Ammonia: Data Selected as Basis of Final Limitation

For ammonia, EPA is promulgating a compliance alternative with a daily maximum 

limitation for airports that use deicers containing urea on the runways. This section describes the 

data selected as the basis of the final limitation for ammonia. 

After evaluating the available data, EPA transferred the 1-day-lag serial correlation value 

from the AFB technology, which is the model technology for COD. This transfer was necessary 

because an AFB system by design creates ammonia as a by-product of wastewater treatment. 

Consequently, AFB discharges could have higher ammonia concentrations than typically found 

in airfield stormwater when airfield deicers containing urea are not used. If the treated aircraft 

deicing stormwater discharges then were discharged to the same pipe as the runway wastewater, 

the airport might have difficulties complying with the ammonia limitation. EPA also confirmed 

that ADF treatment provided less concentrated discharges than observed from the application of 

urea products (ERG. 2009). For these reasons, EPA determined that it was appropriate to use the 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

182

ADF data as a basis of limitations that would apply to discharges associated with runway 

deicing. 

As it had for COD, EPA initially evaluated the Albany data for setting final limitations 

for ammonia, because EPA had data on the performance of its model technology. In contrast to 

its practice of monitoring COD at the end of each treatment unit, the airport monitored ammonia 

at its permit compliance point after additional treatment provided by an aerobic polishing step. 

The anaerobic polishing step would result in decreased ammonia concentrations and would not 

represent ammonia discharges from using urea on airfields. Thus, to promulgate an effluent limit 

consistent with the model technology, EPA used the EPA data and excluded the Albany 

ammonia data (criterion 3). 

Instead, because they reflect the capability of the model treatment system, EPA used its 

sampling data from EPA_SP-2, shown in Table 13-6, as the basis of the final ammonia 

limitations. (Section 13.6 describes field duplicates and the importance of daily values for the 

limitation calculations.) In analyzing samples from this episode, the laboratory achieved a 

detection limit of 0.05 mg/L. During the laboratory’s quality assurance step of the chemical 

analysis, it detected ammonia in the laboratory preparation blank at a concentration of 0.069 

mg/L. Other quality assurance parameters, initial calibration blanks and continuing calibration 

blanks, were between 0.052 mg/L and 0.054 mg/L. The ammonia results for all samples are 

greater than 10 times the blank result, with the exception of four influent and one source water 

samples that were not used as the basis of the final limitation. Consequently, EPA determined 

that the data were of acceptable quality to use as the basis of the final limitation. 

Table 13-6. Ammonia: Data from Albany Airport Used to Develop Limitations 

Sample Day 

Ammonia Concentrations (mg/L) 

Influent 

Effluent 

Original Sample 

Field Duplicate 

(where collected) 

Daily Value Used in 

Limitations Calculations 

1 ND (0.1) 2.58 2.58 

2 ND (0.1) 4.14 3.95 4.05 

3 ND (0.1) 4.45 5.54 5.00 

4 ND (0.1) 6.12 6.12 

5 0.91 6.65 6.65 

ND – Not Detected 

13.6 Limitations: Basis and Calculations

The final limitations, as presented in the final rule, are provided as the daily maximum 

limitations for COD and ammonia. In addition, the notice includes a weekly average limitation 

for COD. This section defines the limitations (Section 13.6.1) and describes the statistical 

percentile basis of the limitations (Section 13.6.2) and the estimation of the percentiles for COD 

and ammonia (Sections 13.6.3). The statistical support memorandum (USEPA, 2010) describes 

the calculations used to model the ammonia data. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

183

13.6.1 Definitions 

Definitions provided in 40 CFR 122.2 describe the limitations in terms of “daily 

discharge,” which it defines as “the ‘discharge of a pollutant’ measured during a calendar day or 

any 24-hour period that reasonably represents the calendar day for purposes of sampling.” 

Therefore, EPA generally arithmetically averages all measurements recorded for each uniquely 

reported time period (e.g., 12/21/2004) before calculating limitations. EPA refers to this 

averaged value as the “daily value.” 

First, in calculating the limitations, EPA ensures that it has only one value for each day. 

Field duplicates are one example of multiple measurements, and were included in the ammonia 

data used to develop the final limitations. Field duplicates are two samples collected at the same 

sample point at approximately the same time, flagged as duplicates for a single sample point, and 

measured separately. Because the analytical data from each duplicate pair characterize the same 

conditions at that time at a single sample point, EPA typically averages the data to obtain one 

data value for those conditions on that day. For example, Table 13-6 shows the field duplicates 

and daily, averaged values for ammonia. 

Second, EPA uses the daily values in calculating the limitations. Definitions provided in 

40 CFR 122.2 further describe the “maximum daily discharge limitation” as the “highest 

allowable ‘daily discharge.’” The “average weekly discharge limitation” is the “highest 

allowable average of ‘daily discharges’ over a calendar week, calculated as the sum of all ‘daily 

discharges’ measured during a calendar week divided by the number of ‘daily discharges’ 

measured during that week.” 

13.6.2 Percentile Basis of the Limitations 

EPA uses a statistical framework to establish limitations that facilities are capable of 

complying with at all times. Statistical methods are appropriate for dealing with effluent data 

because the quality of effluent, even in well-operated systems, is subject to a certain amount of 

fluctuation or uncertainty. Statistics is the science of dealing with uncertainty in a logical and 

consistent manner. Statistical methods together with engineering analysis of operating 

conditions, therefore, provide a logical and consistent framework for analyzing a set of effluent 

data and determining values from the data that form a reasonable basis for effluent limitations. 

Using statistical methods, EPA has derived numerical values for its final daily maximum 

limitations and weekly average limitations. 

The statistical percentiles upon which the limitations are based are intended to be high 

enough to accommodate reasonably anticipated variability within control of the facility. The 

limitations also reflect a level of performance consistent with the CWA requirement that these 

limitations be based on the best technologies that are properly operated and maintained. 

In establishing daily maximum limitations, EPA’s objective is to restrict the discharges 

on a daily basis at a level that is achievable for an airport that targets its treatment system design 

and operation at the long-term average while allowing for the variability around the long-term 

average that results from normal operations. This variability means that at certain times airports 

may discharge at levels that are greater or considerably lower than the long-term average. To 

allow for possibly higher daily discharges, EPA has established the daily maximum limitation at 

a relatively high level (i.e., the 99th percentile). Due to routine variability in treated effluent, an 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

184

airport that discharges consistently at a level near the daily maximum limitation, instead of the 

long-term average, may experience frequent values exceeding the limitations. For this reason, 

EPA recommends that airports target the treatment system at the long-term average that it 

derived for the model technology. 

In its derivation of the weekly average limitation for COD, EPA used an estimate of the 

97th percentile of the weekly averages of the daily measurements. This percentile basis is the 

midpoint of the percentiles used for the daily maximum limitation (i.e., 99th percentile of the 

distribution of daily values) and the monthly average limitation (i.e., 95th percentile of the 

distribution of monthly average values). Courts have upheld EPA’s use of these percentiles, and 

the selection of the 97th percentile is a logical extension of this practice. Compliance with the 

daily maximum limitation is determined by a single daily value; therefore, EPA feels the 99th 

percentile provides a reasonable basis for the daily maximum limitation by allowing for an 

occasional extreme discharge. Because compliance with the monthly average limitation is based 

upon more than one daily measurement and averages are less variable than daily discharges, 

EPA has determined that facilities should be able to control the average of daily discharges to 

avoid extreme monthly averages above the 95th percentile. Similar to the monthly average 

limitation, compliance with the weekly average limitation also would be based upon more than 

one daily measurement. However, the airport would monitor for a shorter time and thus would 

have fewer opportunities to counterbalance highly concentrated daily discharges with lower 

ones. For this reason, EPA is utilizing a larger percentile for the weekly average limitation than 

the one used for the monthly average limitation. Consequently, EPA is using the 97th percentile 

as an appropriate basis for limiting average discharges on a weekly basis. EPA also considers 

this level of control in avoiding extreme weekly average discharges to be possible for airports 

using the model technology. 

13.6.3 Estimation Procedures for Percentiles 

This section describes the estimation procedures that EPA used to calculate the 

limitations for the final rulemaking. Sections 13.6.3.1, and 13.6.3.2 describe the estimation 

procedures used to model the COD data and the June 8, 2009, memorandum on calculation of 

percentiles (Westat. 2009) describes the calculations used by the statistical software. Section 

13.6.3.3 describes the procedures for ammonia. 

Table 13-7 summarizes the limitations that EPA established for COD and ammonia. 

Because of the importance of targeting treatment to the long-term average, EPA recommends 

that facilities design, maintain, and operate the treatment system to achieve a long-term average 

of 52.8 mg/L, which is the median of the averages from the two units (52.28 mg/L for 

ArprtR_101 and 53.40 for ArprtR_102, as shown in Table 13-5). The allowance for variability, 

or the ratio of the limitation to the long-term average, is 5.13. (EPA usually refers to this 

allowance as the “variability factor.”) In other words, the daily maximum limitation is 5.13 times 

greater than the long-term average achievable by the model technology. By targeting the system 

to the long-term average and controlling its variability within this range, the facility will be able 

to comply with the limitation. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

185

Table 13-7. COD and Ammonia: Final Limitations with Long-Term Averages and 

Variability Factors 

Parameter Time Period COD Ammonia 

Limitations (mg/L) Daily Maximum 271 14.7 

Weekly Average 154 NA 

Long-Term Average (mg/L) All 52.8 5.24 

Variability Factors Daily 5.13 2.81 

Weekly 2.92 NA 

NA – Not applicable 

13.6.3.1 COD: Daily Maximum Limitation and the 99th Percentile 

For COD, EPA based the final daily maximum limitation on an estimate of the 99th

percentile of the distribution of the daily values. This section describes the percentile estimates 

and the long-term average. 

First, EPA used nonparametric methods to estimate the 99th percentile of the daily values 

from each unit. A simple nonparametric estimate of the 99th percentile of an effluent 

concentration data set is the observed value that exceeds 99 percent of the observed data points. 

Because EPA had more than 1,200 data points for each unit, it determined that the empirical 

approach would provide reasonable estimates of the 99th percentiles. 

Second, EPA set the final limitation equal to the median of the two 99th percentile 

estimates, or 271 mg/L. The median is, by definition, the midpoint of all available data values 

ordered (i.e., ranked) from smallest to largest. As result, half of the unit 99th percentiles are 

higher than the median and half are lower. (In this particular case, because there are two units, 

the median is equal to the arithmetic average (or mean).) 

Table 13-8 summarizes the percentile estimates for the two units, the minimum and 

maximum values observed in the data, the 50th percentiles, and the 99th percentiles. 

Table 13-8. COD: 99th Percentile Estimates from Each Treatment Unit 

Treatment Unit 

Number of Daily 

Values 

Concentrations (mg/L) 

Minimum 50th Percentile Maximum 99th Percentile

ArprtR-101 1,289 1 37 1042 326 

ArprtR-102 1,273 1 45 725 216 

Median Values 41 271 

13.6.3.2 COD: Weekly Average Limitation and the 97th Percentile 

For the weekly average limitation of COD, EPA first calculated, for each unit, the 

arithmetic average of the measurements observed during each week, excluding weekends (to be 

consistent with the assumed monitoring costs, although permit authorities may specify different 

monitoring requirements). EPA then used the nonparametric method to derive a 97th percentile of 

the more than 200 weekly averages for each unit, and set the final limitation equal to the median 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

186

of the two 97th percentile estimates, or 154 mg/L. The statistical support memorandum (USEPA, 

2010) lists the weekly averages. 

Because data were not always available for every weekday during a week, EPA examined 

whether the weekly averages were affected by the number of weekdays included in the average. 

As shown in Table 13-9, the value of the limitation varied only slightly if the weeks were 

required to have data for all five days. The June 23, 2009, memorandum on percentiles for 

weekly averages (Westat, 2009a) provides a more detailed evaluation. 

Table 13-9. COD: Effect of Number of Daily Values in Weekly Averages 

Number of Daily 

Values in Average 

Unit ArprtR-101 Unit AirprtR-102 

Median of 97th

Percentiles 

Number of 

Weekly Averages 

97th 

Percentile 

Number of Weekly 

Averages 

97th 

Percentile 

5 155 176.8 157 133.6 155.2 

4 or 5 181 176.8 181 133.6 155.2 

1 to 5 1 209 162.4 203 145.5 153.95 

1 Averages in this row were used as the basis of the final weekly average limitation. 

13.6.3.3 Ammonia: Percentile Estimates Based Upon the Lognormal Distribution 

Because the ammonia data set had fewer than 100 observations, EPA used a parametric 

approach to model the data. If a data set comprisese fewer than 100 observations, the best that 

can be done, using nonparametric methods, is to use the maximum value as an approximate 

nonparametric estimate of the 99th percentile, but this can underestimate the true value. 

Parametric methods require that a probability distribution be specified, which allows estimation 

of unknown parameters from the available data. The estimated parameters are a function of the 

defined distribution and the data, and thus the parametric method enables the percentiles of 

effluent concentrations to be computed analytically. EPA’s selection of parametric methods in 

developing limitations for other industries is well documented (e.g., Iron and Steel, Pulp, Paper, 

and Paperboard, and Metal Products and Machinery categories). EPA considers the lognormal 

distribution to be appropriate for the ammonia data, and this section describes its application in 

estimating the final daily maximum limitation. The daily maximum limitation of 14.7 mg/L is 

based upon an estimate of the 99th percentile of the lognormal distribution of the daily values. 

The calculations include an adjustment for possible bias due to statistical autocorrelation. 

The adjusted variance then better reflects the underlying variability that would be present if the 

data were collected over a longer period. When data are said to be positively autocorrelated, it 

means that measurements taken at specific time intervals (such as 1 day or 2 days apart) are 

similar. For example, positive autocorrelation would be present in the data if the final effluent 

concentration was relatively high one day and was likely to remain at similar high values the 

next and possibly succeeding days. EPA sampling data, used as the basis of the limitations, were 

collected on five consecutive days, and thus, the data may be autocorrelated, but the length of 

time was not sufficient for autocorrelation evaluations. Albany Airport’s self-monitoring data 

also were not suitable for the evaluation because they were collected at three-week intervals 

rather than consecutive days. In contrast, the Iron and Steel rule had 244 data points for ammonia 

that generally were collected on consecutive days, so it was possible to evaluate autocorrelation 

in the data. Because the model technologies for both industries are biological systems, EPA 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

187

concludes that the Iron and Steel autocorrelation adjustment is a reasonable transfer that can be 

used to calculate the airport deicing limitations.10 Table 13-10 summarizes the final long-term 

average and daily maximum limitation, with and without the adjustment for autocorrelation. The 

final daily maximum limitation of 14.7 mg/L is 2.8 times greater than the long-term average, of 

5.24 mg/L, achievable by the model technology. By targeting the system to the long-term 

average and controlling its variability within this range, the facility will be able to comply with 

the limitation. However, ammonia is generated as a by-product of the model technology, and 

EPA expects the concentrations of ammonia to have similar variability to what is being treated 

(i.e., COD). In contrast to the COD limitations, which are based on a mixture of start-up and 

steady-state periods, the ammonia limitation is based upon data collected only during steadystate operations. 

Table 13-10. Ammonia: Consideration of Autocorrelation for Final Limitations, LongTerm Averages, and Variability Factors 

Statistical Parameter 

Adjusted for Autocorrelation? Percent 

No Yes (Final) Difference 

Long-Term Average (mg/L) 4.97 5.24 5% 

Variability Factor 2.25 2.81 25% 

Daily Maximum Limitation (mg/L) 11.2 14.7 31% 

Unlike COD, EPA is not setting a weekly ammonia effluent limitation. The technology 

basis for the COD effluent limitations would operate throughout the deicing season with 

continuous discharges allowing for weekly monitoring. In contrast, urea is applied to airfield 

pavement as needed, and discharges would occur for a short time after the initial application, as 

the urea works its way through the stormwater collection and any associated treatment system 

that may be present. Most airports would have noncontinuous and somewhat infrequent urea 

discharges. Consequently, it would be difficult to assume a single value for the monitoring 

frequency that could reasonably be applied to all airports, regardless of climatic conditions. 

13.6.3.4 Significant Digits for Final Limitations 

In presenting the values of the final limitations, EPA rounded the values to three 

significant digits. EPA used a rounding procedure where values of five and above are rounded up 

and values of four and below are rounded down. For example, a value of 5.235 would be 

rounded to 5.24, while a value of 5.234 would be rounded to 5.23. 

13.7 Achievability of Limitations

EPA promulgates limitations that sites are capable of complying with at all times by 

properly operating and maintaining their processes and treatment technologies. As a consequence 

of using the percentile basis for each final limitation, treatment systems that are designed and 

operated to achieve long-term average levels should be able to comply with the limitations, 

which incorporate variability, at all times. As verification that the limitations are achievable, 

 

10 EPA has not incorporated a similar adjustment for autocorrelation into the data for the COD limitations because 

the limitation is based upon more than 2500 measurements collected over 10 years, which presumably would show a 

full range of variability expected by the model technology. (DCNs AD01210 and AD01214) 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

188

EPA performs additional statistical and engineering reviews, as described in Section 13.7.1. As a 

result of these reviews, EPA has concluded that these limitations are achievable, and thus EPA 

expects facilities to comply with the limitations as explained in Section 13.7.2. 

13.7.1 Statistical and Engineering Review of Limitations 

In conjunction with the statistical methods, EPA performs an engineering review to 

verify that the limitations are reasonable based upon the design and expected operation of the 

control technologies and the airport conditions. The following sections describe two types of 

comparisons. First, EPA compares the final limitations to the data used to develop the 

limitations. Second, EPA compares the limitations to the influent data. 

13.7.1.1 Comparison to Data Used As Basis for the Limitations 

As part of its data evaluations, EPA compared the value of the final limitations to the 

values used to calculate the limitations. None of the data selected for ammonia were greater than 

its final daily maximum limitation that supports the engineering and statistical conclusions that 

the limitation values are appropriate. Because of the statistical methodology used for the COD 

limitations, some values were greater than the final limitations. 

For COD, appropriately one percent of the values were greater than the final daily 

maximum limitation, which is consistent with the statistical basis (i.e., use of the 99th percentile) 

of the limitation. Table 13-11 lists the data from both units and the influent, when one or both 

effluent values were greater than the limitation. Of the 27 values greater than the final limitation, 

20 were from the ArprtR-101 unit, and 7 from ArprtR-102 unit. Both units had values greater 

than the final limitation on three dates: 3/31/2001, 1/4/2005, and 12/25/2008. 

Of the 412 weekly averages of the COD concentrations, 12 averages had values that were 

greater than the final weekly average limitation of 154 mg/L. Of those 12 averages, 10 were 

during weeks when the unit also had one or more daily values that were greater than the daily 

maximum limitation. The statistical support memorandum (USEPA, 2010) identifies the weeks 

and the corresponding daily values. 

13.7.1.1 Comparison to Influent 

In addition to evaluating the data used as the basis of the limitations, EPA often compares 

the value of the final limitations to influent concentration levels. In these comparisons, EPA 

determines if the limitations perform as expected. 

As part of its evaluation to determine if the COD limitation was sufficiently stringent to 

require that the influent be treated, EPA evaluated the COD influent discharges from Albany 

Airport. As shown in the summary statistics in Table 13-12, all influent values were greater than 

the final limitation during nine deicing seasons. For the season 06, only two values (1/1/2007 and 

1/2/2007) were less than the final limitation.11 This finding confirmed that the final limitation 

can only be met through treatment. 

 

11 For both dates, the facility reported the same values for influent (100 mg/L), the same values for ArprtR-101 (30 

mg/L), and the same estimated values for ArprtR-102. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

189

Table 13-11. COD: Dates and Values Greater than Final Limitation of 271 mg/L 

Season Date 

COD Concentrations (mg/L) 1

ArprtR_101 ArprtR_102 

Season99 

16MAR2000 326 33 

23MAR2000 315 93 

Season00 

01MAR2001 276 232 

11MAR2001 288 64 

12MAR2001 575 92 

22MAR2001 129 393 

31MAR2001 357 288 

Season02 

18MAY2003 (Estimated to be 800) 2 685 

19MAY2003 460 95 

20MAY2003 655 86 

22MAY2003 290 101 

Season03 

20DEC2003 278 2 

03JAN2004 690 36 

08JAN2004 387 37 

08FEB2004 435 74 

09FEB2004 453 49 

16MAR2004 316 124 

17MAR2004 699 118 

Season04 

04JAN2005 275 725 

04FEB2005 38 360 

Season05 09DEC2005 162 275 

Season07 

09JAN2008 1,042 Out of service 

10JAN2008 433 Out of service 

Season08 25DEC2008 674 282 1

 Bold text indicates effluent values greater than the limitations. 

2

This value was not used in calculating the limits because it was an estimated value (see DCN AD01246) 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

190

Table 13-12. COD: Summary Statistics of Influent Concentrations 

Season #of Days 

COD: Influent Concentration (mg/L) 

Standard 

Deviation Minimum Maximum Median 

Arithmetic 

Average 

Season99 141 1,536 1,000 6,560 2,784 3,242 

Season00 115 1,257 1,797 7,950 5,505 5,208 

Season01 167 1,505 342 7,105 3,975 3,949 

Season02 187 1,825 2,915 10,470 7,270 7,144 

Season03 145 2,412 655 10,060 6,520 5,996 

Season04 141 1,790 1,848 8,870 5,580 5,272 

Season05 85 1,685 528 7,410 4,900 4,373 

Season06 62 1,700 100 5,760 1,880 2,588 

Season07 127 2,132 485 11,000 7,540 6,805 

Season08 120 4,409 3,550 18,300 8,875 10,022 

ALL 1,290 2,928 100 18,300 5,490 5,630 

13.7.2 Compliance with Limitations 

EPA promulgates limitations that sites are capable of complying with at all times by 

properly operating and maintaining their processes and treatment technologies. However, the 

issue of exceedances or excursions (values that exceed the limitations) is often raised. In other 

rules, including EPA’s final OCPSF rule, commenters suggested that EPA include a provision 

that a facility is in compliance with permit limitations provided its discharge does not exceed the 

specified limitations, with the exception that the discharge may exceed the daily maximum 

limitation 1 day out of 100. EPA’s general approach in that case for developing limitations based 

on percentiles was the same as this rule and was upheld in Chemical Manufacturers Association 

v. U.S. Environmental Protection Agency, 870 F.2d 177, 230 (5th Cir. 1989). The Court 

determined the following: 

EPA reasonably concluded that the data points exceeding the 99th and 95th 

percentiles represent either quality-control problems or upsets because there can 

be no other explanation for these isolated and extremely high discharges. If these 

data points result from quality-control problems, the exceedances they represent 

are within the control of the plant. If, however, the data points represent 

exceedances beyond the control of the industry, the upset defense is available. 

Id. at 230. 

This issue also was raised in EPA’s Phase I rule for the Pulp, Paper, and Paperboard 

Category (USEPA, 1998). In that rulemaking, EPA used the same general percentile approach 

for developing monthly average limitations that it used for daily maximum limitation for the 

airport deicing rule. The percentile approach for the monthly average limitation was upheld in 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

191

National Wildlife Federation et al. v. Environmental Protection Agency, 286 F.3d 554, 573 (D.C. 

Cir. 2002). The Court determined that: 

EPA’s approach to developing monthly limitations was reasonable. It established 

limitations based on percentiles achieved by facilities using well-operated and 

controlled processes and treatment systems. It is therefore reasonable for EPA to 

conclude that measurements above the limitations are due to either upset 

conditions or deficiencies in process and treatment system maintenance and 

operation. EPA has included an affirmative defense that is available to mills that 

exceed limitations due to an unforeseen event. EPA reasonably concluded that 

other exceedances would be the result of design or operational deficiencies. EPA 

rejected Industry Petitioners’ claim that facilities are expected to operate 

processes and treatment systems to violate the limitations at some pre-set rate. 

EPA explained that the statistical methodology was used as a framework to 

establish the limitations based on percentiles. These limitations were never 

intended to have the rigid probabilistic interpretation that Industry Petitioners 

have adopted. Therefore, we reject Industry Petitioners’ challenge to the effluent 

limitations. 

As that Court recognized, EPA’s allowance for reasonably anticipated variability in its 

effluent limitations, coupled with the availability of the upset defense, reasonably accommodates 

acceptable excursions. Any further excursion allowances would go beyond the reasonable 

accommodation of variability and would jeopardize the effective control of pollutant discharges 

on a consistent basis and/or bog down administrative and enforcement proceedings in detailed 

fact-finding exercises, contrary to Congressional intent. See, for example, Rep. No. 92-414, 92d 

Congress, 2d Sess. 64, reprinted in A Legislative History of the Water Pollution Control Act 

Amendments of 1972 (at 1482); Legislative History of the Clean Water Act of 1977 (at 464-65). 

More recently, for EPA’s rule for the iron and steel industry, EPA’s selection of 

percentiles was upheld in American Coke and Coal Chemicals Institute v. Environmental 

Protection Agency, 452 F.3d 930, 945 (D.C. Cir. 2006). The Court determined that: 

The court will not second-guess EPA’s expertise with regard to what the 

maximum effluent limits represent. See Nat’l Wildlife, 286 F.3d at 571-73. As 

EPA explains in the Final Development Document, the daily and monthly average 

effluent limitations are not promulgated with the expectation that a plant will 

operate with an eye toward barely achieving the limitations. Final Development 

Document at § 14.6.2. Should a plant do so, it could be expected to exceed these 

limits frequently because of the foreseeable variation in treatment effectiveness. 

Rather, the effluent limitations are promulgated with the expectation that plants 

will be operated with an eye towards achieving the equivalent of the long term 

average for the BAT-1 model technology. Id. However, even operated with the 

goal of achieving the BAT-1 long term average, a plant’s actual results will vary. 

EPA’s maximum daily limitations are designed to be forgiving enough to cover 

the operations of a well-operated model facility 99% of the time, while its 

maximum monthly average limitations are designed to be forgiving enough to 

accommodate the operations of a well-operated model facility 95% of the time. 

See id. EPA’s choice of percentile distribution represented by its maximum 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

192

effluent limitation under the CWA represents an expert policy judgment that is 

not arbitrary or capricious. 

EPA expects that airports will comply with promulgated limitations at all times. If an 

exceedance is caused by an upset condition, the airport would be able to defend against an 

enforcement action if it meets the requirements of 40 CFR 122.41(n). If the exceedance is caused 

by a design or operational deficiency, EPA has determined that the airport’s performance does 

not represent the appropriate level of control (best available technology for existing sources; best 

available demonstrated technology for new sources). For promulgated limitations and standards, 

EPA has determined that such exceedances can be controlled by diligent process and wastewater 

treatment system operational practices such as frequent inspection and repair of equipment, use 

of backup systems, and operator training and performance evaluations. 

13.8 References

ERG. 2008. Personnel communication (email) between Mary Willett (ERG) and Mark Sober, 

Albany International Airport. (July 22). DCN AD00824. 

ERG. 2008a. Email from Mark Sober (Albany International Airport) to Mary Willett (ERG). RE: 

One More Query. (July 22). DCN AD01206. 

ERG. 2008b. Telecon between Cortney Itle (ERG) and Mark Sober (Albany International 

Airport). RE: ALB Follow-up Questions. (August 14). DCN AD00825. 

ERG. 2009. Memorandum from Mary Willett (ERG) to Brian D’Amico (EPA). Evaluation of 

Proposed Compliance Alternative Ammonia Limitations with respect to Airport Deicing 

Stormwater Typical Ammonia Discharges. (June 30). DCN AD01194. 

USEPA. 1987. Organic Chemicals and Plastics and Synthetic Fibers Category Effluent 

Limitations Guidelines, Pretreatment Standards and New Source Performance Standards; Final 

Rule. 40 CFR Part 414, 52 FR 42522, November 5, 1987. 

USEPA. 1998. National Emission Standards for Hazardous Air Pollutants for Source Category: 

Pulp and Paper Production; Effluent Limitations Guidelines, Pretreatment Standards, and New 

Source Performance Standards: Pulp, Paper, and Paperboard Category; Final Rule. 40 CFR 

Part 430, 63 FR 18503, April 15, 1998. 

USEPA. 2002. Development Document for Effluent Limitations Guidelines and Standards for the 

Iron and Steel Manufacturing Point Source Category. EPA-821-R-02-004. Section 14.1. 

Available online at www.epa.gov/guide/ironsteel/. 

USEPA. 2006. Notice of Availability of Final 2006 Effluent Guidelines Program Plan. 

December 21, 2006; 71 FR 76655. 

USEPA. 2010. Memorandum from Cuc Schroeder (EPA) to Brian D’Amico (EPA). Statistical 

Support Memorandum. (November). DCN AD01246. 

Westat. 2009. Memorandum from John Rogers (Westat) to Marla Smith (EPA). Calculation 

Percentiles. (June 8). DCN AD01213. 
Technical Development Document for Effluent 

Limitation Guidelines and Standards for the Airport Deicing Category 

Section 13 – Limitations and Standards: Data Selection and Calculation 

193

Westat. 2009a. Memorandum from John Rogers (Westat) to Marla Smith (EPA). Percentiles for 

Weekly Averages. (June 23). DCN AD01214.