United States Office of Water EPA 833-R-10-005

Environmental Protection Washington, DC 20460 August 2010

Agency www.epa.gov/npdes Final Report

Report to Congress:

Study of Discharges

Incidental to Normal

Operation of Commercial

Fishing Vessels and Other

Non-Recreational Vessels

Less than 79 Feet

i 
ACKNOWLEDGMENTS 

The EPA Office of Wastewater Management (OWM) presents this draft Vessels 

Study Report to Congress conducted to meet the obligations of EPA under Public Law 

(P.L.) 110-299 (July 31, 2008). EPA would like to thank the numerous trade associations 

and individual companies who contributed to this project. Those groups who provided 

assistance to EPA are listed in Chapter 2 of this report. The project could not have been 

successful without the support by EPA Region 2, 3, and 5 laboratories, EPA Gulf 

Ecology Division and other EPA program offices. EPA would also like to thank the 

United States Coast Guard for providing both logistical support and review of many of 

the report’s elements. Finally, EPA would also like to acknowledge the contractor 

support for this project provided by individuals from Great Lakes Environmental Center, 

Inc., Eastern Research Group, and Abt Associates. 

i 
The primary technical contacts for this document are: 

Ryan Albert 

U.S. Environmental Protection Agency 

Office of Water (Mail Code: 4203M) 

1200 Pennsylvania Avenue, NW 

Washington, DC 20460 

(202) 564-0763 (telephone) 

(202) 564-6392 (fax) 

Robin Danesi 

U.S. Environmental Protection Agency 

Office of Water (Mail Code: 4203M) 

1200 Pennsylvania Avenue, NW 

Washington, DC 20460 

(202) 564-1846 (telephone) 

(202) 564-6392 (fax) 

The primary EPA congressional relations contact for this document is: 

Greg Spraul 

U.S. Environmental Protection Agency 

Office of Congressional and Intergovernmental Relations (Mail Code: 1301A) 

1200 Pennsylvania Avenue, NW 

Washington, DC 20460 

(202) 564-0255 (telephone) 

(202) 564-1519 (fax) 

ii 
TABLE OF CONTENTS 

EXECUTIVE SUMMARY ........................................................................................................ xv

CHAPTER 1 Introduction to the Report ................................................................................... 1

1.1. Congressional Study Charge................................................................................... 1

1.2. Organization of this report...................................................................................... 2

1.3. Classes or Types of Vessels.................................................................................... 2

1.3.1. Commercial Fishing Vessels................................................................................... 3

1.3.2. Tugs/Towing Vessels.............................................................................................. 8

1.3.3. Water Taxis/Small Ferries ...................................................................................... 9

1.3.4. Tour Boats............................................................................................................... 9

1.3.5. Recreational Vessels Used for Non-Recreational Purposes ................................. 10

1.4. Vessel Population.................................................................................................. 11

1.4.1. Vessel Characteristics Data................................................................................... 11

1.4.2. Overview of Vessel Universe ............................................................................... 12

1.5. Discharges from Vessels....................................................................................... 24

1.5.1. Bilgewater............................................................................................................. 25

1.5.2. Deck Washdown and Deck Runoff....................................................................... 25

1.5.3. Engine Effluent ..................................................................................................... 26

1.5.4. Firemain Systems.................................................................................................. 28

1.5.5. Fish Hold and Fish Hold Cleaning Effluent (Refrigerated Seawater Discharge or 

Fish Ice Slurry Discharge) .................................................................................... 29

1.5.6. Graywater.............................................................................................................. 31

1.5.7. Shaft Packing Gland Effluent ............................................................................... 31

1.5.8. Antifouling Hull Coatings..................................................................................... 32

1.6. Pollutants Potentially Found in Vessel Discharges .............................................. 32

1.6.1. Classical Pollutants ............................................................................................... 33

1.6.2. Nutrients................................................................................................................ 35

1.6.3. Pathogen Indicators............................................................................................... 36

1.6.4. Metals.................................................................................................................... 36

1.6.5. Volatile and Semivolatile Organic Compounds ................................................... 36

1.6.6. Nonylphenols ........................................................................................................ 37

1.7. Chapter Conclusions ............................................................................................. 37

CHAPTER 2 Study Design ........................................................................................................ 39

2.1 Data Sources ......................................................................................................... 39

2.1.1 Existing EPA Data Sources .................................................................................. 39

2.1.2 Industry Participation............................................................................................ 40

2.1.3 Vessel Sampling.................................................................................................... 42

2.1.4 Literature Review.................................................................................................. 42

2.1.5 Other Governmental Data Sources ....................................................................... 42

2.2 EPA Vessel Discharge Sampling Program........................................................... 43

2.2.1 Vessels Sampled and Locations............................................................................ 44

2.2.2 Sampled Discharges.............................................................................................. 49

2.2.3 Target Analytes..................................................................................................... 51

2.2.4 Sampling Methods ................................................................................................ 53

2.2.5 QA/QC .................................................................................................................. 58

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2.3 Data Considerations and study limitations ........................................................... 61

2.3.1 Voluntary Nature of the Sampling Program ......................................................... 61

2.3.2 Vessels/Discharges Not Sampled ......................................................................... 62

2.3.3 Pollutants Not Sampled......................................................................................... 63

2.3.4 Application to Other Vessels, Including Larger Vessels Not Sampled for this 

Study ..................................................................................................................... 63

CHAPTER 3 Analysis of Discharges and Potential Impact to Human Health and the 

Environment........................................................................................................ 67

3.1 Approach to Analyses........................................................................................... 67

3.1.1 Data Reduction and Presentation.......................................................................... 68

3.1.2 Summary Statistics and Box Plots ........................................................................ 69

3.1.3 Calculation of Potential Hazard Quotients ........................................................... 70

3.2 Characterization of Discharges............................................................................. 79

3.2.1 Bilgewater............................................................................................................. 79

3.2.2 Stern Tube Packing Gland Effluent .................................................................... 115

3.2.3 Deck Washdown ................................................................................................. 143

3.2.4 Fish Hold and Fish Hold Cleaning Effluent (Refrigerated Seawater and Ice 

Slurry) ................................................................................................................. 188

3.2.5 Graywater............................................................................................................ 234

3.2.6 Engine Effluent ................................................................................................... 261

3.2.7 Firemain Discharges ........................................................................................... 338

3.2.8 Antifouling Hull Coatings................................................................................... 354

CHAPTER 4 Potential Large-Scale Impacts of Study Vessels’ Incidental Discharges to 

Human Health and the Environment.............................................................. 368

4.1 Model Selection .................................................................................................. 370

4.2 Fraction of Freshwater Model............................................................................. 371

4.2.1 Step 1: Calculate Vessel Discharge Analyte Loading Rates .............................. 372

4.2.2 Step 2: Calculate the Fraction of Freshwater in the Harbor................................ 373

4.2.3 Step 3: Calculate the Harbor Flushing Time....................................................... 373

4.2.4 Step 4: Calculate the Harbor Analyte Concentration.......................................... 374

4.3 Vessel Discharge Loading Rates ........................................................................ 374

4.3.1 Calculate the Average Analyte Concentrations .................................................. 374

4.3.2 Discharge Flow Rate Assumptions..................................................................... 375

4.3.3 Number of Vessels Present in the Harbor........................................................... 381

4.3.4 Percentage of Vessels Discharging in the Harbor............................................... 385

4.3.5 Vessel Discharge Loading Rates ........................................................................ 387

4.3.6 Dissolved Copper Loading Rates from Antifouling Paints ................................ 387

4.4 Hypothetical Harbor............................................................................................ 389

4.5 Model Scenarios.................................................................................................. 391

4.6 Model Results ..................................................................................................... 393

4.6.1 Dilution Factor Analysis..................................................................................... 393

4.6.2 Supplemental Model Run in Response to Comments......................................... 394

4.6.3 Loading Rate Analysis........................................................................................ 395

4.7 Conclusions......................................................................................................... 399

CHAPTER 5 Summary of Findings........................................................................................ 401

5.1 Summary of Classes of Vessels Covered By this Study..................................... 401

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5.2 Summary of Effluent Characterization of Select Discharges from the Study 

Vessels ................................................................................................................ 401

5.2.1 Estimated Volumes of Select Discharges from the Study Vessels..................... 402

5.2.2 Analytes of Potential Risk in Select Discharges from Study Vessels ................ 404

5.3 Summary of Predicted Impacts from Select Pollutants in Study Vessel 

 Discharges........................................................................................................... 417

5.3.1 Potential Watershed-Wide Impacts from Study Vessels .................................... 417

5.3.2 Potential Localized or Near-Field Impacts of Vessel Discharges to Receiving 

Waters ................................................................................................................. 418

5.4 Possible Benefits to Human Health, Welfare, and the Environment from 

Reducing, Eliminating, Controlling, or Mitigating One or More of the Discharges 

from the Study Vessels ....................................................................................... 420

CHAPTER 6 Analysis of the Extent to Which Incidental Discharges are Currently Subject 

to Regulation Under Federal Law or a Binding International Obligation of 

the United States ............................................................................................... 422

6.1 International Agreements.................................................................................... 422

6.1.1 The International Convention for the Prevention of Pollution from Ships 

(MARPOL 73/78) ............................................................................................... 422

6.1.2 The International Convention on the Control of Harmful Anti-Fouling Systems on 

Ships.................................................................................................................... 432

6.1.3 International Convention for the Safety of Life at Sea (SOLAS)....................... 435

6.1.4 Boundary Waters Treaty..................................................................................... 436

6.1.5 Great Lakes Water Quality Agreement............................................................... 436

6.1.6 St. Lawrence Seaway Regulations...................................................................... 439

6.2 Federal Laws....................................................................................................... 440

6.2.1 Act to Prevent Pollution from Ships (APPS)...................................................... 440

6.2.2 Clean Water Act (CWA) §§ 311, 312/Oil Pollution Control Act....................... 444

6.2.3 Organotin Antifouling Paint Control Act ........................................................... 446

6.2.4 National Invasive Species Act ............................................................................ 447

6.2.5 Hazardous Materials Transportation Act............................................................ 448

6.2.6 National Marine Sanctuaries Act........................................................................ 448

6.2.7 Resource Conservation and Recovery Act ......................................................... 449

6.2.8 Federal Insecticide, Fungicide, and Rodenticide Act ......................................... 450

6.3 Additional International and Federal Laws......................................................... 451

6.3.1 International Convention on the Prevention of Marine Pollution by Dumping of 

Wastes and Other Matter .................................................................................... 451

6.3.2 International Convention on Oil Pollution, Preparedness, Response and 

Cooperation......................................................................................................... 452

6.3.3 International Convention Relating to Intervention on the High Seas in Cases of 

Oil Pollution Casualties ...................................................................................... 452

6.3.4 Comprehensive Environmental Response, Compensation, and Liability Act.... 452

6.3.5 CWA § 402, National Pollutant Discharge Elimination System (NPDES)........ 453

6.3.6 Title XIV of the Consolidated Appropriations Act, 2001—Certain Alaskan Cruise 

Ship Operations................................................................................................... 453

6.3.7 Toxic Substances Control Act ............................................................................ 453

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6.4 Application of Legal Authorities to Discharges Incidental to the Normal 

Operation of Study Vessels................................................................................. 454

CHAPTER 7 References .......................................................................................................... 458

Appendix A List of Acronyms ................................................................................................. A-1

Appendix B Additional Characteristics of the P.L. 110 – 299 Vessel Population............... B-1

B.1 Vessel Subcategories .......................................................................................... B-1

B.1.1 Population of Vessels undergoing Discharge Analysis ...................................... B-2

B.2 Vessel Geographical Area of Operation ............................................................. B-4

B.3 Other Vessel Characteristics: Construction and Propulsion ............................. B-11

B.3.1 Vessel Age ........................................................................................................ B-12

B.3.2 Hull Material Type............................................................................................ B-13

B.3.3 Propulsion Method and Type............................................................................ B-15

B.3.4 Horsepower Ahead............................................................................................ B-16

B.4 Distribution of the Study Vessel Universe versus the Recreational Vessel 

Universe ............................................................................................................ B-18

B.5 Vessels Documented, Inspected, and/or State Registered ................................ B-25

B.6 Uncertainty........................................................................................................ B-26

Appendix C Public Law 110-299 (S. 3298) and Public Law 110-288 (S. 2766) ................... C-1

Appendix D List of Target Analytes ....................................................................................... D-1

Appendix E Analyte Concentrations and Summary Statistics from Ambient Water Samples

............................................................................................................................ E-1

Appendix F Analyte Concentrations and Summary Statistics from Source Water Samples

.............................................................................................................................F-1

Appendix G Supporting Information for EPA’s Screening-Level Water Quality Model .G-1

Appendix H Responsiveness Summary...................................................................................H-1

Appendix I List of Preparers and Contributors ......................................................................I-1

vi 
LIST OF TABLES 

Table 1.1. Population of Operational, Domestic MISLE Vessels by Vessel Length ................... 14 

Table 2.1. Number of Vessels Sampled by Vessel Class and Discharge ..................................... 46

Table 2.2. Analyte Groups by Discharge...................................................................................... 52 

Table 3.1. Water Quality and Other Benchmark Values Used to Screen the Vessel Discharge 

Data................................................................................................................................... 75

Table 3.2. Major Cation Concentrations in Seawater................................................................... 78

Table 3.3. Major Cation Concentrations in Freshwater................................................................ 78 

Table 3.1.1. Results of Bilgewater Sample Analyses for Dissolved Metals................................. 85

Table 3.1.2. Results of Bilgewater Sample Analyses for Total Metals ........................................ 86

Table 3.1.3. Results of Bilgewater Sample Analyses for Classical Pollutants............................. 93

Table 3.1.4. Results of Bilgewater Sample Analyses for Pathogen Indicators............................. 97

Table 3.1.5. Results of Bilgewater Sample Analyses for Nutrients.............................................. 99

Table 3.1.6. Results of Bilgewater Sample Analyses for SVOCs .............................................. 103

Table 3.1.7. Results of Bilgewater Sample Analyses for VOCs ................................................ 108

Table 3.1.8. Results of Bilgewater Sample Analyses for Nonylphenols.................................... 112

Table 3.1.9. Characterization of Bilgewater Discharge and Summary of Analytes that May Have 

the Potential to Pose Risk ............................................................................................... 114 

Table 3.2.1. Results of Packing Gland Effluent Sample Analyses for Metals ........................... 118

Table 3.2.2. Results of Packing Gland Effluent Sample Analyses for Classical Pollutants....... 125

Table 3.2.3. Results of Packing Gland Effluent Sample Analyses for Nutrients ....................... 129

Table 3.2.4. Results of Packing Gland Water Sample Analyses for SVOCs and VOCs............ 133

Table 3.2.5. Results of Packing Gland Water Sample Analyses for Nonylphenols ................... 139

Table 3.2.6. Characterization of Packing Gland Effluent and Summary of Analytes that May 

Have the Potential to Pose Risk...................................................................................... 142 

Table 3.3.1. Results of Deck Washdown/Runoff Sample Analyses for Metals ......................... 152

Table 3.3.2. Dissolved-to-Total Metal Ratios (fds) in Paired Deck Washdown/Runoff 

 Samples........................................................................................................................... 154

Table 3.3.3. Minimum and Maximum Dissolved and Total Metal Concentrations in Vessel 

Source and Ambient (Harbor) Water Relative to Median Sample Concentrations and 

Most Stringent Screening Benchmarks........................................................................... 154

Table 3.3.4. Comparison of Metal Concentrations in Deck Washdown Discharge Between 

Fishing Vessels and Non-Fishing Vessels ...................................................................... 155

Table 3.3.5. Mean Concentrations of Dissolved and Total Heavy Metals from Deck Wash 

Discharges from Fishing Vessels and Nonfishing Vessels............................................. 156

Table 3.3.6. Results of Deck Washdown Water Sample Analyses for Classical Pollutants ...... 164

Table 3.3.7. Results of Deck Washdown Water Sample Analyses for Pathogen Indicators...... 169

Table 3.3.8. Results of Deck Washdown Water Sample Analyses for Nutrients....................... 174

Table 3.3.9. Results of Deck Washdown Water Sample Analyses for Long-Chain 

 Nonylphenols .................................................................................................................. 178

Table 3.3.10. Results of Deck Washdown Water Sample Analyses for VOCs and SVOCs...... 182

Table 3.3.11. Characterization of Deck Washdown and Runoff Water and Summary of Analytes 

that May Have the Potential to Pose Risk....................................................................... 187 

Table 3.4.1. Results of Fish Hold Effluent Sample Analyses for Total Metals.......................... 195

Table 3.4.2. Results of Fish Hold Effluent Sample Analyses for Dissolved Metals .................. 196

vii 
Table 3.4.3. Results of Fish Hold Cleaning Effluent Sample Analyses for Metals.................... 202

Table 3.4.4. Results of Fish Hold Effluent Sample Analyses for Classical Pollutants............... 210

Table 3.4.5. Results of Fish Hold Cleaning Effluent Analyses for Classical Pollutants ............ 211

Table 3.4.6. Results of Fish Hold and Fish Hold Cleaning Effluent Sample Analyses for 

Pathogen Indicators......................................................................................................... 217

Table 3.4.7. Results of Fish Hold (upper half) and Fish Hold Cleaning Effluent (lower half) 

Sample Analyses for Nutrients ....................................................................................... 221

Table 3.4.8. Raw Sewage Concentrations of Nutrients .............................................................. 221

Table 3.4.9. Results of Fish Hold Cleaning Effluent Sample Analyses for Long-chain 

Nonylphenols .................................................................................................................. 226

Table 3.4.10. Means (and Standard Deviations) for Selected Analyte Concentrations, by 

Geographic Region. Units for All Analytes Expressed as μg/L, Except for 

 BOD (mg/L).................................................................................................................... 230

Table 3.4.11. Characterization of Fish Hold Effluent and Fish Hold Cleaning Effluent and 

Summary of Analytes that May Have the Potential to Pose Risk................................... 233 

Table 3.5.1. Results of Graywater Sample Analyses for Pathogen Indicators ........................... 236

Table 3.5.2. Results of Graywater Sample Analyses for Classical Pollutants............................ 241

Table 3.5.3. Results of Graywater Sample Analyses for Nonylphenols (only long-chain NPEOs 

and OPEOs were detected) ............................................................................................. 245

Table 3.5.4. Results of Graywater Sample Analyses for Dissolved Metals ............................... 248

Table 3.5.5. Results of Graywater Sample Analyses for Total Metals....................................... 249

Table 3.5.6. Results of Graywater Sample Analyses for Nutrients ............................................ 255

Table 3.5.7. Characterization of Graywater Effluent and Summary of Analytes that May Have 

the Potential to Pose Risk ............................................................................................... 260 

Table 3.6.1. Sampled Engine Characteristics ............................................................................. 263

Table 3.6.2. Results of Inboard Propulsion Engine Sample Analyses for Classical Pollutants . 267

Table 3.6.3. Results of Inboard Propulsion Engine Sample Analyses for Metals...................... 271

Table 3.6.4. Comparison of Metals Results for EPA P.L. 110-299 and UNDS Engine Wet 

Exhaust Sampling ........................................................................................................... 273

Table 3.6.5. Results of Inboard Propulsion Engine Sample Analyses for SVOCs..................... 280

Table 3.6.6. Comparison of Phenol Results for EPA P.L. 110-299 and UNDS Engine Wet 

Exhaust Sampling ........................................................................................................... 281

Table 3.6.7. Results of Inboard Propulsion Engine Sample Analyses for VOCs....................... 286

Table 3.6.8. Results of Outboard Propulsion Engine Sample Analyses for Classical 

 Pollutants......................................................................................................................... 292

Table 3.6.9. Results of Outboard Propulsion Engine Sample Analyses for Metals ................... 295

Table 3.6.10. Results of Outboard Propulsion Engine Sample Analyses for SVOCs................ 302

Table 3.6.11. Results of Outboard Propulsion Engine Sample Analyses for VOCs .................. 305

Table 3.6.12. Results of Generator Engine Sample Analyses for Classical Pollutants .............. 310

Table 3.6.13. Results of Generator Engine Sample Analyses for Metals................................... 313

Table 3.6.14. Results of Generator Engine Sample Analyses for SVOCs ................................. 319

Table 3.6.15. Results of Generator Engine Sample Analyses for VOCs.................................... 324

Table 3.6.16. Mean Concentration Results, UNDS Engine Wet Exhaust Discharge and 

Background Samples for the LCPL ................................................................................ 330

Table 3.6.17. Mean Concentration Results, UNDS Engine Wet Exhaust Discharge and 

Background Samples for the RIB ................................................................................... 331

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Table 3.6.18. Comparison of Dewinterizing Effluent with Propulsion Effluent........................ 333

Table 3.6.19. Comparison of Number of Detected Analytes in Engine Effluent ....................... 334

Table 3.6.20. Comparison of Results for Selected Analytes in Engine Effluent........................ 334

Table 3.6.21. Characterization of Engine Effluent and Summary of Analytes that May Have the 

Potential to Pose Risk ..................................................................................................... 336 

Table 3.7.1. Results of Firemain System Sample Analyses for Metals...................................... 341

Table 3.7.2. Results of Firemain System Water Sample Analyses for Classical Pollutants....... 347

Table 3.7.3. Results of Firemain Water Sample Analyses for SVOCs....................................... 350

Table 3.7.4. Characterization of Firemain Discharge and Summary of Analytes that May Have 

the Potential to Pose Risk ............................................................................................... 353 

Table 3.8.1. Rates of Passive Copper Leaching from Vessel AFSs ........................................... 361

Table 3.8.2. Dissolved Copper Release from Vessel AFSs During an Underwater Hull Cleaning 

“Event”............................................................................................................................ 362

Table 3.8.3. Estimated Dissolved Copper Mass Emissions from a 9.1m (30ft) Powerboat....... 362 

Table 4.3.1. Offload Frequency by Fishing Vessel Subtype ...................................................... 376

Table 4.3.2. Examples of Field Data and Assumptions for Flow Rate Calculations by 

 Discharge ........................................................................................................................ 377

Table 4.3.3. Vessel Flow Rates................................................................................................... 379

Table 4.3.4. Vessel Population Scenario Representative Harbors Based on the Top 20 Hailing 

Ports Cited in the MISLE Database................................................................................ 382

Table 4.3.5. Percentage of Study Vessels Present in Representative Fishing Harbor................ 383

Table 4.3.6. Percentage of Study Vessels Present in Representative Large Metropolitan 

 Harbor ............................................................................................................................. 383

Table 4.3.7. Percent of Study Vessels Present in Representative Recreational Harbor ............. 384

Table 4.3.8. Vessel Population Scenarios................................................................................... 385

Table 4.3.9. Percentage of Vessels Discharging in the Harbor .................................................. 386

Table 4.3.10. Estimated Average Vessel Length by Vessel Class.............................................. 388 

Table 4.4.1. Harbors Selected for Model Input Parameter Development................................... 389

Table 4.4.2. Hypothetical Harbor Input Parameters ................................................................... 390

Table 4.4.3. Hypothetical Harbor Scenarios............................................................................... 391 

Table 4.5.1. Fraction of Freshwater Model Scenarios................................................................ 392 

Table 4.6.1. “Tipping Point” Dilution Factors for Harbor Instantaneous Concentration to Equal 

the NRQWC Based on Vessel Population Scenario Loading Rates 1 ............................ 394

Table 4.6.2. Revised Model Assumptions .................................................................................. 394

Table 4.6.3. Supplemental Model Run “Tipping Point” Dilution Factors for Harbor Instantaneous 

Concentration to Equal the NRQWC Based on Vessel Population Scenario Loading 

 Rates................................................................................................................................ 395

Table 4.6.4. Comparison of Model Loading Rates with Other Potential Point Source Loading 

Rates................................................................................................................................ 398 

Table 5.1. Analytes of Potential Risk by Discharge ................................................................... 411 

Table 6. 1. International Treaties and Federal Laws Applicable to Discharges Incidental to the 

Normal Operation of Vessels...................................................................................................... 455

Table 6.2. International Treaties and Federal Laws Applicable to Vessels (by Length)............ 457

ix 
LIST OF FIGURES 

Figure 1.1. MISLE Population of Operational, Domestic Non-Recreational Vessels by Vessel 

Service................................................................................................................... 13

Figure 1.2. Number of Study Vessels Recorded in MISLE, by Vessel Service (Type) ............... 16

Figure 1.3. Relationship Between Vessel Gross Tons and Length............................................... 19

Figure 1.4. Distribution of MISLE Vessels by Length and Vessel Service (Type)...................... 20

Figure 1.5. Cumulative Distribution of MISLE Vessels by Length and Vessel Service (Type).. 21

Figure 1.6. Distribution of Study Vessels by Length (in Feet) and Vessel Service (Type).......... 22

Figure 1.7. Distribution of Study Vessels by Gross Tons and Vessel Service (for which gross ton 

data are given in MSLE)....................................................................................... 23 

Figure 3.1.1. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Bilgewater .......................................................................................... 87

Figure 3.1.2. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Bilgewater............................................................................................................. 88

Figure 3.1.3. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Bilgewater .......................................................................................... 89

Figure 3.1.4. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Bilgewater .......................................................................................... 90

Figure 3.1.5. Box and Dot Density Plot of Classical Pollutant Concentrations Measured in 

Samples of Bilgewater .......................................................................................... 94

Figure 3.1.6. Box and Dot Density Plot of Potential Hazard Quotients for Classical Parameters in 

Samples of Bilgewater .......................................................................................... 95

Figure 3.1.7. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of 

Bilgewater........................................................................................................... 100

Figure 3.1.8. Box and Dot Density Plot of Potential Hazard Quotients for Nutrients in Samples of 

Bilgewater........................................................................................................... 101

Figure 3.1.9. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Bilgewater........................................................................................................... 104

Figure 3.1.10. Box and Dot Density Plot of Potential Hazard Quotients for SVOCs in Samples of 

Bilgewater........................................................................................................... 105

Figure 3.1.11. Box and Dot Density Plot of VOC Concentrations Measured in Samples of 

Bilgewater........................................................................................................... 109

Figure 3.1.12. Box and Dot Density Plot of Potential Hazard Quotients for VOCs in Samples of 

Bilgewater........................................................................................................... 110 

Figure 3.2.1. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Packing Gland Effluent.................................................................... 120

Figure 3.2.2. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Packing Gland Effluent....................................................................................... 121

Figure 3.2.3. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Packing Gland Effluent.................................................................... 122

Figure 3.2.4. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Packing Gland Effluent.................................................................... 123

Figure 3.2.5. Box and Dot Density Plot of Classical Pollutants Measured in Samples of Packing 

Gland Effluent..................................................................................................... 126

x 
Figure 3.2.6. Box and Dot Density Plot of Potential Hazard Quotients for Classical Pollutants in 

Samples of Packing Gland Effluent.................................................................... 127

Figure 3.2.7. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of 

Packing Gland Effluent....................................................................................... 130

Figure 3.2.8. Box and Dot Density Plot of Potential Hazard Quotients for Nutrients in Packing 

Gland Effluent..................................................................................................... 131

Figure 3.2.9. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Packing Gland Effluent Samples ........................................................................ 134

Figure 3.2.10. Box and Dot Density Plot of VOC Concentrations Measured in Samples of 

Packing Gland Effluent Samples ........................................................................ 135

Figure 3.2.11. Box and Dot Density Plot of Potential Hazard Quotients for SVOCs in Samples of 

Packing Gland Effluent....................................................................................... 136

Figure 3.2.12. Box and Dot Density Plot of Potential Hazard Quotients for VOCs in Samples of 

Shaft Packing Gland Effluent ............................................................................. 137

Figure 3.2.13. Box and Dot Density Plot of Nonylphenol Concentrations Measured in Samples of 

Packing Gland Effluent....................................................................................... 140 

Figure 3.3.1. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Deck Washdown Water ................................................................... 157

Figure 3.3.2. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Deck Washdown Water ...................................................................................... 158

Figure 3.3.3. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Deck Washdown Water ................................................................... 159

Figure 3.3.4. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Deck Washdown Water ................................................................... 160

Figure 3.3.5. Box and Dot Density Plot of Classical Pollutants Measured in Samples of Deck 

Washdown Water................................................................................................ 165

Figure 3.3.6. Box and Dot Density Plot of Potential Hazard Quotients for Classical Pollutants in 

Samples of Deck Washdown Water ................................................................... 166

Figure 3.3.7 Box and Dot Density Plot of Pathogen Indicator Concentrations Measured in 

Samples of Deck Washdown Water ................................................................... 170

Figure 3.3.8. Box and Dot Density Plot of Potential Hazard Quotients for Pathogens in Samples 

of Deck Washdown Water.................................................................................. 171

Figure 3.3.9. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of Deck 

Washdown Water................................................................................................ 175

Figure 3.3.10. Box and Dot Density Plot of Potential Hazard Quotients for Nutrients in Samples 

of Deck Washdown Water.................................................................................. 176

Figure 3.3.11. Box and Dot Density Plot of Nonylphenol Concentrations Measured in Samples of 

Deck Washdown Water ...................................................................................... 179

Figure 3.3.12. Box and Dot Density Plot of Volatile Organic Chemical Concentrations Measured 

in Samples of Deck Washdown Water ............................................................... 183

Figure 3.3.13. Box and Dot Density Plot of Potential Hazard Quotients for VOCs in Samples of 

Deck Washdown Water ...................................................................................... 184 

Figure 3.4.1. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Fish Hold Effluent............................................................................................... 197

Figure 3.4.2. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Fish Hold Effluent............................................................................ 198

xi 
Figure 3.4.3. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Fish Hold Effluent............................................................................ 199

Figure 3.4.4. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Fish Hold Effluent............................................................................ 200

Figure 3.4.5. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Fish Hold Cleaning Effluent ............................................................................... 203

Figure 3.4.6. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Fish Hold Cleaning Effluent ............................................................ 204

Figure 3.4.7. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Fish Hold Cleaning Effluent ............................................................ 205

Figure 3.4.8. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Fish Hold Cleaning Effluent ............................................................ 206

Figure 3.4.9. Box and Dot Density Plot of Classical Pollutant Concentrations/Values Measured 

in Samples of Fish Hold Effluent........................................................................ 212

Figure 3.4.10. Box and Dot Density Plot of Classical Pollutant Concentrations/Values Measured 

in Samples of Fish Hold Cleaning Effluent ........................................................ 213

Figure 3.4.11. Comparison Between the BOD Secondary Treatment Limit from Sewage 

Treatment Facilities (30 mg/L), Average BOD Raw Sewage Concentrations, and 

BOD Concentrations from Fish Hold Effluent and Fish Hold Cleaning 

Effluent ............................................................................................................... 214

Figure 3.4.12. Box and Dot Density Plot of Measured Pathogen Concentrations in Samples of 

Fish Hold Effluent............................................................................................... 218

Figure 3.4.13. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of 

Fish Hold Effluent............................................................................................... 222

Figure 3.4.14. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of 

Fish Hold Cleaning Effluent ............................................................................... 223

Figure 3.4.15. Comparison of Concentrations of Ammonia, TKN, and Total Phosphorus in 

Different Fishing Vessel Platforms to those in the Lobster Tank (which has a live 

catch and continuously circulating water) .......................................................... 224

Figure 3.4.16. Box and Dot Density Plot of Nonylphenol Concentrations Measured in Samples of 

Fish Hold Cleaning Effluent ............................................................................... 227 

Figure 3.5.1. Box and Dot Density Plot of Pathogen Indicator Values Measured in Samples of 

Graywater............................................................................................................ 237

Figure 3.5.2. Box and Dot Density Plot of Potential Hazard Quotients for Pathogen Indicators 

Measured in Samples of Graywater.................................................................... 238

Figure 3.5.3. Box and Dot Density Plot of Classical Pollutant Concentrations/Values Measured 

in Samples of Graywater..................................................................................... 242

Figure 3.5.4. Box and Dot Density Plot of Potential Hazard Quotients for Classical Pollutants in 

Samples of Graywater......................................................................................... 243

Figure 3.5.5. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Graywater......................................................................................... 250

Figure 3.5.6. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Graywater............................................................................................................ 251

Figure 3.5.7. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Graywater......................................................................................... 252

xii 
Figure 3.5.8. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Graywater......................................................................................... 253

Figure 3.5.9. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of 

Graywater............................................................................................................ 256

Figure 3.5.10. Box and Dot Density Plot of Potential Hazard Quotients for Nutrients in Samples 

of Graywater ....................................................................................................... 257 

Figure 3.6.1. Box and Dot Density Plot of Classical Pollutant Values Measured in Samples of 

Inboard Propulsion Engine Effluent ................................................................... 268

Figure 3.6.2. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Inboard Propulsion Engine Effluent ................................................ 274

Figure 3.6.3. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Inboard Propulsion Engine Effluent ................................................................... 275

Figure 3.6.4. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Inboard Propulsion Engine Effluent ................................................ 276

Figure 3.6.5. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Inboard Propulsion Engine Effluent ................................................ 277

Figure 3.6.6. Box and Dot Density Plot of SVOC Concentrations Measured in P.L. 110-299 

Study Samples of Inboard Propulsion Engine Effluent ...................................... 282

Figure 3.6.7. Box and Dot Density Plot of Potential Hazard Quotients for SVOCs in P.L. 110-

299 Study Samples of Inboard Propulsion Engine Effluent ............................... 283

Figure 3.6.8. Box and Dot Density Plot of Volatile Organic Compounds Concentrations 

Measured in P.L. 110-299 Study Samples of Inboard Propulsion Engine 

Effluent ............................................................................................................... 288

Figure 3.6.9. Box and Dot Density Plot of Potential Hazard Quotients for Volatile Organic 

Compounds in P.L. 110-299 Study Samples of Inboard Propulsion Engine 

Effluent ............................................................................................................... 289

Figure 3.6.10. Box and Dot Density Plot of Classical Pollutant Values Measured in Samples of 

Outboard Propulsion Engine Effluent................................................................. 293

Figure 3.6.11. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Outboard Propulsion Engine Effluent.............................................. 297

Figure 3.6.12. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Outboard Propulsion Engine Effluent................................................................. 298

Figure 3.6.13. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Outboard Propulsion Engine Effluent.............................................. 299

Figure 3.6.14. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Outboard Propulsion Engine Effluent.............................................. 300

Figure 3.6.15. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Outboard Propulsion Engine Effluent................................................................. 303

Figure 3.6.16. Box and Dot Density Plot of Volatile Organic Compounds Concentrations 

Measured in Samples of Outboard Propulsion Engine Effluent......................... 306

Figure 3.6.17. Box and Dot Density Plot of Potential Hazard Quotients for Volatile Organic 

Compounds in Samples of Outboard Propulsion Engine Effluent ..................... 307

Figure 3.6.18. Box and Dot Density Plot of Classical Pollutant Values Measured in Samples of 

Generator Engine Effluent .................................................................................. 311

Figure 3.6.19. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Generator Engine Effluent ............................................................... 314

xiii 
xiv 

Figure 3.6.20. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Generator Engine Effluent .................................................................................. 315

Figure 3.6.21. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Generator Engine Effluent ............................................................... 316

Figure 3.6.22. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Generator Engine Effluent ............................................................... 317

Figure 3.6.23. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Generator Engine Effluent .................................................................................. 321

Figure 3.6.24. Box and Dot Density Plot of Potential Hazard Quotients for SVOCs in Samples of 

Generator Engine Effluent .................................................................................. 322

Figure 3.6.25. Box and Dot Density Plot of VOC Concentrations Measured in Samples of 

Generator Engine Effluent .................................................................................. 326

Figure 3.6.26. Box and Dot Density Plot of Potential Hazard Quotients for VOCs in Samples of 

Generator Engine Effluent .................................................................................. 327 

Figure 3.7.1. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Firemain Water ................................................................................ 342

Figure 3.7.2. Box and Dot Density Plot of Total Metals Concentrations Measured in Samples of 

Firemain Water ................................................................................................... 343

Figure 3.7.3. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals in 

Samples of Firemain Water ................................................................................ 344

Figure 3.7.4. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Firemain Water ................................................................................ 345

Figure 3.7.5. Box and Dot Density Plot of Classical Pollutants Measured in Samples of Firemain 

Water................................................................................................................... 348

Figure 3.7.6. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Firemain Water ................................................................................................... 351
Executive Summary 

EXECUTIVE SUMMARY

This report to Congress provides information collected by the U.S. Environmental Protection 

Agency (EPA) on the types of wastewater discharged from commercial fishing vessels and 

nonrecreational vessels less than 79 feet in length. The report also provides information on the primary 

pollutant concentrations in these discharges and the likelihood of any resulting environmental impacts 

based on rate, frequency, volume, and location discharged. This study was conducted to meet the 

obligations of EPA under Public Law (P.L.) 110-299 (July 31, 2008). The law provided for a 

temporary two-year moratorium on National Pollutant Discharge Elimination System (NPDES) 

permitting of discharges from commercial fishing vessels, regardless of size, and other nonrecreational 

vessels less than 79 feet long that were subject to the 40 CFR 122.3(a) exclusion. Except for ballast 

water discharges (evaluated and assessed elsewhere in other Agency reports), discharges from these 

vessels are not currently covered under the EPA’s Vessel General Permit (VGP). During the two-year 

moratorium, which began July 31, 2008, EPA was required to study the relevant discharges. EPA 

believes that the results from this study will serve as an objective source of information that Congress 

can use for statutory decision-making and will provide other readers valuable technical analyses of 

these vessels’ incidental discharges. EPA requested public comment on this draft report in March, 

2010: this final report incorporates changes made in response to these comments. 

As directed by Congress, the goal of the study was to obtain sufficient information to address 

the following six core objectives: 

 A characterization of the nature, type, and composition of discharges for representative 

single vessels and for each class of vessel. 

 A determination of the volumes of those discharges, including the average volumes for 

representative single vessels and for each class of vessel. 

 A description of the locations, including the more common locations, of the discharges; 

 An analysis of the nature and extent of the potential effects of the discharges, including 

determinations of whether the discharges pose risks to human health, welfare, or the 

environment, and the nature of those risks. 

 A determination of the benefits to human health, welfare, and the environment from 

reducing, eliminating, controlling, or mitigating the discharges. 

 An analysis of the extent to which the discharges are currently subject to regulation under 

federal law or a binding international obligation of the United States. 

xv
Executive Summary 

EPA designed and conducted a sampling program of discharges from commercial fishing 

vessels and other nonrecreational vessels less than 79 feet in length to provide information to achieve 

the first two objectives of the study. As required in P.L. 110-299, the study specifically evaluated the 

impacts of any 1) discharge of effluent from properly functioning marine engines; 2) discharge of 

laundry, shower, and galley sink wastes; and 3) other discharges incidental to these vessels’ normal 

operation. In addition, EPA supplemented sample collection and analysis with the collection of 

contemporaneous information regarding the shipboard processes, equipment, materials, and operations 

that contribute to the discharges, as well as the discharge rates, duration, frequency, and location. 

EPA found that commercial fishing vessels and nonrecreational vessels discharge a wide 

variety of effluents during their normal operation. The Agency decided to focus its evaluation on 

discharges from engines, bilges, fish holds, decks, and graywater activities because such discharges 

can release oils, heavy metals, toxic organics, oxygen-depleting substances, nutrients, and endocrinedisrupting compounds to ambient waters in quantities that may exceed National Recommended Water 

Quality Criteria (NRWQC). In some circumstances, some of these vessel discharges to water bodies 

have the potential to impact the aquatic environment. 

Vessel Types 

EPA estimates there are between 118, 000 and 140,000 vessels in the United States subject to 

the permitting moratorium (i.e., study vessels).1

 Figure ES. 1 presents the estimated number of study 

vessels by vessel types (service). Approximately one-half of these vessels are commercial fishing 

vessels involved in activities such as fish catching (e.g., longliner, shrimper, trawler), fish processing, 

fishing tending, and charter fishing. The other half is distributed among a variety of vessel classes, 

including passenger vessels (e.g., water taxis, tour boats, harbor cruise ships, dive boats), utility vessels 

(e.g., tug/tow boats, research vessels, offshore supply boats), and freight barges. 

 

1

 Based on the U.S. Coast Guard Marine Information for Safety and Law Enforcement (MISLE) database. See discussion in 

Chapter 1 and Appendix B of this report for detailed discussions about vessel estimates and limitations of these estimates. 

xvi
Executive Summary 

xvii

4,288 67 287 49

15,012

8,876

56,407

18,660

579 -

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

Commercial

Fishing Vessel

Freight Barge

Freight Ship

Passenger

Vessel

Public Vessel,

Unclassified

Tank Barge

Tank Ship

Utility Vessel

Unspecified

Vessel Service

Number of Vessels

Other non-recreational

69,944

8,016

768

20,953

622 923 179

11,034

27,375

140,000 - Total number of vessels, 

including vessels of unspecified length

118,000 - Number of vessels with 

specified length less than 79 feet

Vessels with unspecified length

Vessels less than 79 feet in length

Figure ES.1. Estimated Number of Study Vessels by Vessel Service (Type) 

To select specific vessel classes for sampling, EPA first developed a list of commercial vessel 

classes based on published information and industry experience. Next, due to limited time and 

resources, EPA eliminated those vessel classes believed to consist primarily of vessels greater than 79 

feet in length, with the exception of commercial fishing vessels. Examples of vessel classes eliminated 

because of their size included cable laying ships, cruise ships, large ferries, and oil and petroleum 

tankers. Next, EPA eliminated vessel classes that have historically been subject to NPDES permitting, 

including stationary seafood processing vessels and vessels that can be secured to the ocean floor for 

mineral or oil exploration. After screening out these vessel classes, EPA selected a subset of priority 

vessel classes to study, including commercial fishing boats, tug/tow boats, water taxis, tour boats, 

recreational vessels used for nonrecreational purposes, and industrial support boats less than 79 feet in 

length. EPA selected these vessel classes because they represent a cross section of discharges and have 

the potential to release a broad range of pollutants. 

EPA sampled wastewater discharges and gathered shipboard process information from 61 

vessels in nine vessel classes. Vessels were sampled in 15 separate cities and towns in nine states 

across multiple geographic regions, including New England, the Mid-Atlantic, the Gulf Coast, the 
Executive Summary 

Mississippi River, and Alaska. Table ES.1 presents the types of vessels from which EPA sampled and 

gathered shipboard process information for this study. EPA sampled more commercial fishing vessels 

than any other vessel class due to the large number of fishing vessels subject to the P.L. 110-299 

permitting moratorium. EPA also sampled a few recreational vessels used for commercial purposes 

(e.g, towboats) to: 1) provide a semiquantitative comparison of the discharges from these vessels and 

the other study vessels, and 2) collect additional information for EPA’s related Clean Boating Act (P.L. 

110-288) work. 

Table ES.1. Vessels Sampled by EPA 

Vessel Class Number of Vessels Sampled 

Fishing: 

Gillnetter 5 

Lobster Tank 1 

Longliner 3 

Purse Seiner 5 

Shrimp Trawler 6 

Tender 3 

Trawler 4 

Troller 6 

Tugboat 9 

Water Taxi 4 

Tour Boat 3 

Tow/Salvage 1 6 

Research 1 2 

Fire Boat 1 

Supply Boat 1 

Recreational 2 

Total 61 

(1) Consists primarily of recreational vessels used for commercial or governmental purposes. 

Sampled Discharges

EPA sampled a total of nine discharge types from the various vessel classes listed above. These 

included: 

 Bilgewater 

 Stern tube packing gland effluent 

 Deck runoff and/or washdown 

 Fish hold effluent (both refrigerated seawater effluent and ice slurry) 

 Effluent from the cleaning of fish holds 

 Graywater 

 Propulsion and generator engine effluent 

 Engine dewinterizing effluent 

 Firemain 

EPA typically sampled one to four discharge types on each vessel, depending on applicability, 

accessibility, and logistical considerations. Vessel discharge samples were analyzed for a variety of 

xviii
Executive Summary 

pollutants, including classical pollutants such as biochemical oxygen demand (BOD5), total suspended 

solids (TSS), residual chlorine, and oil and grease; nutrients; total and dissolved metals; volatile and 

semivolatile organic compounds (VOCs and SVOCs); nonylphenols (used as surfactants in detergents), 

which are endocrine-disrupting compounds; and pathogen indicators (i.e., E. coli, enterococci, fecal 

coliforms). 

Summary of Findings

EPA found that the sampled discharges with the greatest potential to impact surface water 

quality include deck washdown, fish hold effluent, graywater, bilgewater, and marine engine effluent. 

Though these discharges may have the potential to impact surface water quality, particularly on a 

localized scale, a screening level model of a hypothetical large harbor indicates that most of these 

discharges in and of themselves would not cause exceedences of national water quality criteria in large 

water bodies (see additional discussion under environmental impacts below). Review of available 

literature also indicates that leachate from antifouling hull coatings used on certain vessels to prevent 

buildup of organisms, such as barnacles and algae, as well as underwater hull cleaning, likely impact 

surface water quality in some situations. 

Deck washdown from utility vessels such as tug/tow boats, tour boats, water taxis, and supply 

boats had elevated dissolved and total metal concentrations (e.g., aluminum) likely associated with 

particulate metal washing off metal decks or decks with significant metal components. Certain deck 

washdown samples also contained pollutants such as BOD5, TSS, nonylphenols, total phosphorous, 

and total residual chlorine, all of which are associated with detergents and disinfectants. 

Fish hold effluent, which is either refrigerated seawater or ice slurry water found on fishing 

boats, had BOD5 and chemical oxygen demand (COD) concentrations that were several times higher 

than concentrations typically measured in raw domestic sewage. Nutrient levels in many fish hold 

effluent samples were also similar to the concentrations normally found in raw domestic sewage, and 

ammonia nitrogen was occasionally detected at concentrations acutely toxic to aquatic life. While 

small fishing boats periodically discharge only a few hundred gallons of fish hold wastewater, large 

fishing vessels, such as offshore trawlers, can discharge thousands of gallons of fish hold wastewater 

in a matter of minutes. 

Most fishing vessel owners also clean the fish hold tanks with a detergent and/or disinfectant 

after the fish have been off-loaded. Detergents are suspected of containing nonylphenols, which are 

endocrine-disrupting compounds. Disinfectants such as chlorine bleach contain high concentrations of 

total residual chlorine, which is toxic to aquatic organisms. The samples of fish hold cleaning effluent 

contained nonylphenols and total residual chlorine, along with the same pollutants measured in the fish 

hold effluent. 

Galleys, sinks, showers, and laundry facilities onboard commercial vessels generate graywater, 

which is typically discharged overboard. Graywater volumes vary considerably depending on the class 

of vessel and its intended use, vessel size, the number of crew and passengers onboard, and the types 

of graywater-generating activities. Pollutants associated with the various graywater sources depend on 

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Executive Summary 

a variety of factors, such as the amount of food waste flushed into the graywater system, the level of 

soiling on clothing being washed in the onboard laundry, and the use of showers. EPA did not sample 

graywater mixed with sewage, so the results for this study are for graywater only. EPA’s sampling data 

found pathogens to be the primary pollutant of concern in graywater. The sampling data show that at 

least one of the pathogenic organisms (fecal coliforms, enterococci, and E. coli) was found in all 

graywater samples, and that levels of these indicators in most of these samples exceeded the water 

quality benchmarks, some by as much as four orders of magnitude. 

Bilgewater effluent consists of the water that collects in the bottom of the vessel from sources 

such as precipitation and spray, fuel spills, leaking sewage and graywater piping, condensates, and 

deck washing. Bilgewater contained the greatest variety (although not necessarily the highest 

concentrations) of priority pollutants, including both total and dissolved metals, VOCs, and SVOCs. It 

also contained pathogenic bacteria, nonylphenols, sulfide, total phosphorous, BOD5, TSS, and residual 

chlorine. Both total arsenic and dissolved copper concentrations in bilgewater were consistently above 

the most conservative screening benchmarks (e.g., EPA’s 2006 NRWQC), and total arsenic 

concentrations were nearly 1,000 times the safe human health standard. 

Propulsion and generation engine effluent varied dependent upon the type of engine. EPA 

found that inboard propulsion engines discharge more pollutants in their cooling water than outboard 

propulsion engines or generators. EPA also found that VOCs and SVOCs are the primary pollutants of 

concern found in marine engine cooling water discharges. These pollutants (e.g., benzene and several 

PAHs, including some that are carcinogenic, or cancer causing) are present in fuels and are products of 

incomplete combustion. Dissolved copper was also measured in most inboard engine effluents at 

concentrations that exceed the NRWQC. Some vessel owners in cold climates also add a solution of 

propylene glycol (antifreeze) to the internal cooling system of inboard engines to protect them from 

freezing during winter. In spring, the antifreeze solution may be discharged as the cooling system is 

refilled with ambient water. EPA’s sampling data showed that the spent antifreeze solution discharged 

to surface water contained relatively high levels of metals, which are likely a result of corrosion within 

the engine’s cooling system. 

Stern tube packing gland effluent (from tug boats) and firemain discharges (limited to just two 

tug boats, three tour boats, and a fireboat) contained elevated levels of some metals (e.g., dissolved 

copper, total aluminum, total arsenic). For both of these discharges (firemain in particular), the effluent 

samples contained relatively small concentrations of pollutants, most of which could be attributed to 

the ambient surrounding water predominating the discharge. For example, stern tube systems have a 

continual drip of ambient water while the shaft is turning to provide both cooling and lubrication for 

the system. The source of the additional metals in stern tube packing gland effluent is likely 

mechanical system wear or lubricants used in the vessels’ power trains. 

Although not directly sampled, EPA gathered existing information from the literature to 

characterize discharges from antifouling hull coatings. Antifouling hull coatings are specialized paints 

and other coatings intended to retard the growth of algae; weeds; and encrusting organisms, such as 

barnacles and zebra mussels, on the underwater portion of vessel hulls. The coatings retard growth by 

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Executive Summary 

continuously leaching biocides into surrounding waters. The most commonly used biocide is cuprous 

oxide. The biocide enters the water column through both passive leaching and underwater hull 

cleaning and can accumulate in the water of poorly flushed boat basins to levels that may harm marine 

life. For example, the leaching of copper from antifouling hull coatings used on recreational boats is a 

major source of copper pollution in several large boat basins in Southern California. Copper from 

antifouling coatings has created documented water quality concerns in areas such as the Chesapeake 

Bay; Port Canaveral, Florida; and several harbors in the state of Washington. 

Environmental Impacts 

Using the results obtained from this study, EPA modeled a large hypothetical harbor to 

evaluate the environmental impacts from the nine above mentioned vessel discharge types that EPA 

sampled. The screening-level model indicated that the study vessels’ discharges would not, in 

themselves, exceed the aquatic life or human health NRWQC; however, the model did not account for 

background loadings. Certain pollutants (e.g., total arsenic, dissolved copper) are more likely to 

contribute to a water quality criterion being exceeded under real-world conditions in large-scale water 

bodies. Additionally, many pollutants present in the vessel discharges were at concentrations that 

exceed an NRWQC at end of pipe; therefore, they have the potential to contribute to an environmental 

effect in the receiving water on a more localized scale. Based on the study results and literature 

reviews, EPA believes that total arsenic and dissolved copper represent the greatest environmental 

concern in vessel discharges, and that they are more likely than other pollutants to contribute to 

exceedances of water quality standards. This is especially true if there are other sources of these 

pollutants (e.g., stormwater runoff) or high concentrations of vessels in confined waters, or the 

receiving waters already have high background concentrations. 

Other notable pollutants of concern were found in fish hold effluent from fishing vessels. These 

pollutants include total phosphorus, BOD, COD, reactive nitrogen compounds, and pathogens. These 

pollutants can exacerbate eutrophication in bays and estuaries, leading to poor surface water quality. 

Analysis of Applicable Regulations 

This report to Congress includes EPA’s analysis of existing laws and treaties that apply to 

vessels and their discharges. This analysis describes numerous domestic laws, including the Act to 

Prevent Pollution from Ships (APPS); the Clean Water Act (CWA); the Federal Insecticide, Fungicide, 

and Rodenticide Act (FIFRA); and the Organotin Antifouling Paint Control Act (OAPC). It also 

summarizes key elements of several international treaties, including the International Convention for 

the Prevention of Pollution from Ships (MARPOL 73/78), the International Convention on the Control 

of Harmful Anti-Fouling Systems on Ships, the International Convention on the Prevention of Marine 

Pollution by Dumping of Wastes and Other Matter (London Convention), and the International 

Convention on Oil Pollution, Preparedness, Response and Cooperation (OPRC). The purpose of this 

analysis is to summarize these existing regulations and international obligations and examine the 

extent to which these discharges are subject to these obligations. 

xxi
Executive Summary 

xxii

Conclusion

Some vessel discharges from commercial fishing vessels and commercial vessels less than 79 

feet in length may have the potential to impact the aquatic environment and/or human health. As noted 

above, using the results obtained in this study, EPA modeled a large, hypothetical harbor to evaluate 

how the nine vessel discharge types EPA sampled may impact water quality. Based on this evaluation, 

EPA determined that the incidental discharges from study vessels to a relatively large water body are 

not likely to solely cause an exceedance of any NRWQC. This finding suggests that these discharges 

are unlikely to pose acute or chronic exceedances of the NRWQC across an entire large water body. 

However, since many of the pollutants present in the vessel discharges were at end-of-pipe 

concentrations that exceeded an NRWQC, there is the potential for these discharges to contribute a 

water quality impact on a more localized scale. The study results indicate that total arsenic and 

dissolved copper are the most significant water quality concerns for the study vessels as a whole, and 

that they are more likely than other pollutants to contribute to exceedances of water quality criteria. 

This is especially true if there are high concentrations of vessels in confined waters or other sources of 

pollutants or the receiving water already has high background concentrations. 

Like an individual house in an urban watershed, most individual vessels have only a minimal 

environmental impact. As in urban waters, however, the impacts caused by these vessels are 

potentially significant where there is high vessel concentration, low water circulation, or there are 

environmentally stressed water bodies. Targeted reduction of certain discharges or pollutants in 

discharges from these vessels in waters sensitive to the introduction of pollutants from vessels may 

result in important significant environmental benefits to those waters. 
Chapter 1 – Introduction to Report 

CHAPTER 1 

INTRODUCTION TO THE REPORT 

1.1. CONGRESSIONAL STUDY CHARGE

On July 31, 2008, Public Law (P.L.) 110-2991

 was signed into law. It provides a two-year 

moratorium for nonrecreational vessels less than 79 feet in length and all commercial fishing vessels 

regardless of length, from the requirements of the National Pollutant Discharge Elimination System 

(NPDES)2

 program to obtain a permit for discharges incidental to the normal operation of those 

vessels.3

 Additionally, P.L. 110-299 directs the United States Environmental Protection Agency (EPA) 

to study the environmental impacts of discharges incidental to the normal operation of those vessels. 

Specifically, the law directs the agency to study and evaluate the impacts of: 

(1) Any discharge of effluent from properly functioning marine engines 

(2) Any discharge of laundry, shower, and galley sink wastes 

(3) Any other discharge incidental to the normal operation of a vessel 

 

Congress mandated that EPA include the following elements in the study: 

(1) Characterizations of the nature, type, and composition of the discharges for: 

a. Representative single vessels 

b. Each class of vessels 

(2) Determinations of the volume (including average volumes) of those discharges for: 

a. Representative single vessels 

b. Each class of vessels 

(3) A description of the locations (including the more common locations) of the discharges. 

(4) Analyses and findings as to the nature and extent of the potential effects of the discharges, 

including determinations of whether the discharges pose a risk to human health, welfare, or the 

environment, and the nature of those risks. 

(5) Determinations of the benefits to human health, welfare, and the environment from reducing, 

eliminating, controlling, or mitigating the discharges. 

(6) Analyses of the extent to which the discharges are currently subject to regulation under federal 

law or a binding international obligation of the United States. 

 

1

 P.L. 110-299, along with its companion law for recreational vessels, P.L. 110-288 (“The Clean Boating Act”) are presented 

in Appendix C of this report. 

2

 The NPDES program requires a permit when a point source discharges a pollutant to waters of the US. A NPDES permit 

contains conditions and limitations on the rates, concentrations, and mass of a pollutant that can be discharged to a water 

body. The limitations are based on available pollution control technologies and water quality standards that are established to

protect the designated uses of a water body, such as fishing or swimming. 

3

 Although this report focuses on the discharges from vessels subject to the moratorium, the Agency became aware during 

interaction with congressional staff that some members may be interested in additional information on discharges incidental 

to the normal operation of a larger universe of vessels—in particular, vessels currently subject to the NPDES General Permit 

for Discharges Incidental to the Normal Operation of a Vessel (“Vessel General Permit”). Therefore, EPA has included some 

additional information and analysis regarding those vessels where possible. 

1 
Chapter 1 – Introduction to Report 

The law expressly excludes certain discharges from the scope of the study: discharges from 

vessels owned and operated by the Armed Forces;4

 discharges of sewage5 from vessels, other than the 

discharge of graywater from vessels operating on the Great Lakes; and discharges of ballast water. 

EPA conducted the study required by P.L. 110-299 and is publishing this report to present its 

findings. Due to the accelerated timeframe required to complete the study, EPA designed this analysis to 

be accomplished quickly with existing resources. Limitations in the study design are discussed in 

Chapter 2 of this report. Due to these factors, EPA focused its sampling efforts on the vessels that P.L. 

110-299 specifically exempted. EPA henceforth refers to these vessels and vessel types as study vessels. 

EPA sampled discharges from a few other vessel types, including commercial vessels that were 

manufactured primarily for pleasure, where resources and logistics allowed. 

1.2. ORGANIZATION OF THIS REPORT

The report is organized into seven chapters. In Chapter 1, EPA describes the universe of vessels 

with discharges subject to the study, the types of discharges generally thought to originate from those 

vessels, and the types of pollutants or other constituents generally found in those vessel discharges. In 

Chapter 2, EPA discusses the methods for sampling, the types of vessels sampled, the Quality Assurance 

and Quality Control (QA/QC) measures taken in the course of sampling, and the limitations of this 

study. Chapter 3 is the most technical portion of the report, presenting the results from EPA’s sampling 

and other information gathered from literature reviews about the vessel discharges. Chapter 4 presents 

the results of EPA’s screening-level model, which was designed to look at the large-scale, cumulative 

impacts of these vessel discharges on large harbor or estuarine systems in order to provide an initial 

evaluation of the threat the discharges pose to these ecosystems. Chapter 5 discusses the results and 

identifies those key areas where EPA found discharges most likely to be a concern to human health, 

welfare, or the environment. Chapter 6 provides a summary of federal law and binding international 

obligations to which discharges within the scope of the study are potentially subject. To a certain extent, 

Chapter 6 also discusses discharges described in the study that might be beyond the scope of the 

permitting moratorium in some circumstances. Chapter 7 lists report references. 

1.3. CLASSES OR TYPES OF VESSELS

The study required by P.L. 110-299 could potentially include numerous classes or types of 

vessels that vary greatly in size. The smallest vessels include recreational boats used for commercial 

purposes, which can be less than 20 feet in length. The largest vessels, such as super oil tankers, can be 

more than 1,200 feet in length. Characteristics of these vessels, including construction material, 

designed purpose, onboard activities, crewing requirements, engine type and power, and days in 

 

4

 The Clean Water Act defines “vessel of the Armed Forces” as any vessel owned or operated by the Department of Defense, 

other than a time or voyage chartered vessel; and any vessel owned or operated by the Department of Transportation that is 

equivalent to one owned by the Department of Defense. 33 U.S.C. § 1322(a)(14). 

5

 “Sewage” is defined as “human body wastes and the wastes from toilets and other receptacles intended to receive or retain 

body wastes except that, with respect to commercial vessels on the Great Lakes, such term shall include graywater.” 33 

U.S.C. § 1322(a) (6). 

2 
Chapter 1 – Introduction to Report 

3 

operation vary widely. Consequently, the types and volumes of discharges generated by these different 

classes or types of vessels also vary to a great extent. 

EPA identified many classes or types of nonrecreational vessels in the development of the 2008 

Vessel General Permit (VGP). Examples include tank ships that transport large volumes of bulk liquids, 

container ships that transport containerized cargo, barges that transport bulk goods, and large cruise 

vessels that transport hundreds or thousands of passengers. In the VGP, EPA defines a “Cruise Ship” as 

a passenger ship that is used commercially for pleasure cruises and provides overnight accommodations 

to passengers. In a separate study, EPA prepared an extensive cruise ship discharge assessment report 

characterizing five different discharge types from these vessels.6

 

The moratorium of P.L. 110-299 applies to discharges from nonrecreational vessels less than 79 

feet in length and all commercial fishing vessels. For some vessel classes or types, such as barges or 

cruise ships, the majority of that class or type are vessels longer than 79 feet. For other classes or types, 

such as container ships or oil tankers, all the vessels would be expected to be longer than 79 feet. EPA 

did not include such vessel classes in this study, as resources did not allow for representative sampling 

of the larger vessels to provide an assessment of the discharges from those classes and still adequately 

sample and assess the vessels specifically exempted by P.L. 110-299. In this study, EPA focused on 

sampling discharges from the most prevalent classes or types of vessels defined by the moratorium 

parameters, but sampled other vessels if the opportunity presented itself. The following subsections 

briefly describe key characteristics of some of the vessels considered for sampling in the study, but this 

list is not intended to be comprehensive. 

1.3.1. Commercial Fishing Vessels

As defined in P.L. 110-299, commercial fishing vessels are vessels that commercially engage in 

the catching, taking, or harvesting of fish or an activity that can reasonably be expected to result in the 

catching, taking, or harvesting of fish. Commercial fishing vessels include any vessels harvesting fish, 

crab, lobster, shrimp, or other aquatic organisms for commercial sale. Commercial fishing vessels may 

employ various methods of collection including nets, trawls, traps, or hook-and-line to capture the target 

species. 

The commercial fishing industry is highly diverse, spanning a wide array of ocean and nearshore 

conditions, differing by both region and fishery. For example, the State of Alaska alone manages 68 

fisheries, and there are over three hundred combinations of species, gear, and regions. Approximately 

half of the nearly 10,000 Alaska State permitted vessels are endorsed for only one fishery; vessels 

working multiple distinct fisheries can be set up in a totally different manner depending on the target 

species (United Fishermen of Alaska, 2010 and Alaska Trollers Association, 2010). Types of fishing 

vessels include, but are not limited to: 

 

6

 This report is available at: www.epa.gov/owow/oceans/cruise_ships/pdf/0812cruiseshipdischargeassess.pdf. 
Chapter 1 – Introduction to Report 

Purse Seiner: Purse seiners catch fish that school close to the surface, such as salmon, herring, 

and sardines, by encircling them with a long net and drawing (pursing) the bottom closed to capture the 

fish. The net is retrieved using a winch. When most of the net has been retrieved, with the remainder 

laying in a “bag” alongside the vessel, the fish are dipped from the bag and into the vessel’s hold. Seinecaught fish are delivered whole. Purse seiners are limited by Alaska law to 58 feet to more precisely 

manage their fishing effort (Alaska Department of Fish and Game, 2007). 

Purse Seiner Fishing Vessel. 

Troller: Troll vessels catch fish such as salmon and tuna by “trolling” bait or lures on lines 

through feeding concentrations of fish. Trolling vessels come in a variety of sizes and configurations, 

ranging from small, hand-trolling skiffs to large, ocean-going power trolling vessels of 50 feet or more 

in length (Alaska Department of Fish and Game, 2007). Hand trollers fish fewer lines and bring fish 

aboard with hand operated gurdies or rod and reel; power trollers use hydraulic gurdies to land their 

catch. Fish caught in the troll fishery are landed one at a time. Most troll-caught fish are immediately 

gilled, gutted, and iced; some are landed in the round and held in slush ice; and a small component is 

frozen at sea. In Alaska, the troll fishery occurs nearly year-round; however, the vast majority of fish are 

delivered between July 1 and September 30 (Alaska Trollers Association, 2010). 

4 
Chapter 1 – Introduction to Report 

Troller Fishing Vessel. 

Crabber/Lobster: Crabbers and lobster boats target crabs (Dungeness, King, Tanner, and Blue) 

and lobsters using twine or wire-meshed steel pots (traps). A line extends from each pot to a surface 

buoy that marks its location; a power winch is used to retrieve the pots. Baited pots are left to “soak” for 

up to several days before retrieval. Once onboard, the pots are opened and sorted with legal 

crabs/lobsters retained in aerated seawater tanks. Crabs/lobsters are delivered live to shore stations and 

retail outlets. Crab and lobster boats come in a variety of shapes and sizes, from aluminum skiffs with 

outboard motors that fish the inside waters, to seagoing vessels 100 or more feet in length that fish the 

Bering Sea and the Gulf of Alaska for King Crab (Alaska Department of Fish and Game, 2007). 

Gillnetter: Gillnetters catch a variety of fish, such as salmon, herring, and chum, by setting 

curtain-like nets perpendicular to the direction in which the fish are traveling as they migrate along the 

coast toward their natal streams. Nets can be set in place, such as at or near the mouths of rivers, or 

allowed to drift freely in deep water. Mesh openings are just large enough to allow the male fish, which 

are usually larger, to get their heads suck in the mesh. Gillnet vessels are usually 30 to 40 feet long and 

are easily recognized by the drum on either the bow or the stern on which the net is rolled. Net retrieval 

is by hydraulic power which turns the drum. Fish are removed from the net by hand as the net is reeled 

aboard. Gillnet-caught fish are usually iced for delivery (Alaska Department of Fish and Game, 2007). 

5 
Chapter 1 – Introduction to Report 

Gillnetter Fishing Vessel. 

Trawler: Trawlers, also occasionally called draggers, typically catch large quantities of midwater species, such as pollock or pink shrimp, and bottom-fish, such as flounder, by towing a large, 

cone-shaped net. The net is retrieved using winches and rolled onto a drum. The end of the net (“bag”) 

holds the fish and is pulled onto the back of the vessel via a slanted stern ramp. Fish such as flounder 

may be processed onboard into fillets or minced. Shrimp are sorted by size and species and frozen either 

whole or headed. Trawlers range in size from small shrimp trawlers to large 600-foot ocean pollock 

trawlers that possess onboard processing facilities (Alaska Department of Fish and Game, 2007). 

Trawler Fishing Vessel. 

6 
Chapter 1 – Introduction to Report 

Longliner: Longliners catch fish (primarily halibut, black cod, swordfish, and tuna) via a 

longline that is either laid on the bottom or suspended in the water column. Each longline can be up to a 

mile in length and have thousands of baited hooks. A longline vessel typically sets several lines for a 24-

hour “soak.” The lines are retrieved over a side roller with a power winch, and the caught fish are 

packed in ice in the vessel’s hold and are delivered whole and bled, whole and gutted, or headed and 

gutted dressed (Alaska Department of Fish and Game, 2007). Longliners range in size from 18-foot 

open skiffs to 80-foot schooners (Alaska Longline Fishermen’s Association, 2010). 

Longliner Fishing Vessel. 

Fishing Dredge: A fishing dredge, also known as a scallop dredge or oyster dredge, is a device 

that is towed along the bottom of the sea by a fishing vessel to collect scallops, oysters, clams, crabs, 

and even in some cases, sea cucumbers. The dredge is winched up into the vessel and emptied onto the 

deck. Dredge boats used to collect clams, oysters, and crabs in near-shore estuarine waters range from 

24 to 50 feet long. Large off-shore dredges used to collect sea scallops can be as long as 190 feet. 

Fish Tender: A fish tender vessel supports fishing vessels by providing supplies and storing, 

refrigerating, or transporting fish, fish products, or other materials. 

7 
Chapter 1 – Introduction to Report 

Tender Vessel. 

1.3.2. Tugs/Towing Vessels

Tugboats and towboats serve many functions and include vessels that operate solely in river 

systems to ocean-going vessels. Tugboats can be utilized to push or tow barges and rafts. Tugboats often 

assist larger vessels in docking maneuvers in harbors and are generally powerful relative to their size. 

Although tugboats and towboats can be over 200 feet in length, many are in the 40- to 100-foot range. 

8 
Chapter 1 – Introduction to Report 

Tugboat/Push Boat. 

1.3.3. Water Taxis/Small Ferries

Water taxis and small ferries (or water busses) are vessels employed to provide public transport 

of people from one location to another. Small ferries are vessels for hire that are designed to carry 

passengers and/or vehicles between two ports, usually in inland, coastal, or near-shore waters. Many of 

these vessels can be found in the coastal harbors of New York, Baltimore, Boston, San Diego, Seattle, 

and others. The sizes of the vessels in this class vary and can surpass 100 feet in length. 

1.3.4. Tour Boats

This vessel class encompasses a variety of vessels used for activities such as dinner cruises, 

ecotourism, whale watching excursions, and sightseeing trips. Vessels in this class can range from small 

private vessels with just a few passengers to large vessels carrying 50 or more passengers. Large tour 

boats designed for extended excursions can include galley facilities, overnight accommodations, and 

laundry. 

9 
Chapter 1 – Introduction to Report 

A Tour Boat (left) and a Water Taxi (right). 

1.3.5. Recreational Vessels Used for Non-Recreational Purposes

This class includes vessels manufactured as recreational vessels that are used for nonrecreational 

purposes, such as law enforcement vessels, fire/rescue vessels, towing and salvage vessels (not to be 

confused with towboats above), and research vessels. This vessel class encompasses a broad range of 

vessel types and sizes. Under the Clean Boating Act of 2008 (P.L. 110-288), vessels that are 

manufactured or used primarily for pleasure are “recreational vessels” subject to regulation under that 

Act. 

Recreational Vessel Modified for Towing/ Salvage. 

10 
Chapter 1 – Introduction to Report 

1.4. VESSEL POPULATION

As discussed in Section 1.1, P.L. 110-299 requires EPA to characterize discharges for 

representative single vessels and for each class of vessel in terms of its nature; type and composition; 

average volume; location; nature and extent of the potential effects; and benefits of reducing, 

eliminating, controlling, or mitigating the discharges. EPA focused its attention on the commercial 

fishing vessels and other nonrecreational vessels less than 79 feet in length covered by the moratorium. 

Understanding the characteristics of discharges from all commercial fishing vessels and nonrecreational 

vessels less than 79 feet in length requires considering these vessels in term of their number, vessel type, 

onboard equipment, type of service, and area of operation. A brief overview of the analysis on vessel 

type and size is presented in this section. A more complete analysis, including a discussion regarding 

vessel location (which impacts the location of vessel discharges) and other vessel characteristics, is 

presented in Appendix B of this report. 

1.4.1. Vessel Characteristics Data

In evaluating and describing the vessel population, EPA primarily relied on data gathered by the 

U.S. Coast Guard. The primary data source used in the vessel population analysis is the U.S. Coast 

Guard’s Marine Information for Safety and Law Enforcement (MISLE) database (USCG, 2009). MISLE 

provides a wide range of information regarding vessel and facility characteristics, accidents, marine 

pollution incidents, and other pertinent information tracked by the U.S. Coast Guard. Where possible, 

EPA complemented the data available in MISLE with information obtained from published sources or 

from consultations with U.S. Coast Guard personnel or port authorities. 

MISLE includes data for nearly 1 million vessels that operate in U.S. waters. The database 

covers a wide ensemble of vessels (e.g., recreational vessels, commercial fishing vessels, freight barges, 

tank barges, tank ships, passenger vessels, utility vessels), and provides data on various characteristics 

for each individual vessel. These data include: 

 Identification number(s) 

 Vessel category (e.g., class, type, subtype, service) 

 Size (e.g., tonnage, length, breadth, depth) 

 Area of operation (e.g., hailing port, route type) 

 Passenger and crew capacity 

 Propulsion (i.e., method, engine type, and horsepower) 

 Construction material and design (e.g., hull material, design type, hull configuration/shape) 

 Year built or age 

In compiling MISLE data, the U.S. Coast Guard largely relies on documents submitted by vessel 

owners or operators in accordance with vessel documentation requirements (e.g., certificate of 

documentation) or on information gathered by U.S. Coast Guard staff directly (e.g., during inspections, 

vessel boardings, or accident investigations). While the database scope is not limited to a certain size or 

class of vessel, the scope of the data included in MISLE is driven in part by the regulatory requirements 

to which different types of vessels are subject or by activities conducted by Coast Guard offices. 

11 
Chapter 1 – Introduction to Report 

MISLE, therefore, is generally most comprehensive for those vessels that are documented, state 

registered, and/or subject to inspection requirements. 

While MISLE represents the most comprehensive national dataset currently available, it does not 

capture the entire universe of vessels operated on U.S. waters. As discussed at greater length in 

Appendix B, only limited information is available for certain classes of vessels, such as smaller 

recreational vessels, due to the way in which vessel data are gathered. Most recreational vessels are not 

subject to documentation or regular inspection requirements and thus are not captured in MISLE.7

 The 

MISLE data set currently contains approximately 700,000 recreational vessels, approximately 36 

percent of which are documented vessels; the other recreational vessels are present in MISLE because of 

other U.S. Coast Guard activities, such as boardings, nonmandatory inspections (e.g., voluntary 

inspection program), or incident investigations.8

 Shortcomings of the database mostly regard small 

recreational vessels. Since recreational vessels are covered separately under the Clean Boating Act of 

2008 (P.L. 110-288) and are therefore not the primary focus of this report, EPA believes that data 

limitations do not preclude the use of the MISLE data for the current analysis to generally describe the 

characteristics of study vessels. 

Additionally, while MISLE captures a wide range of characteristics for each vessel, the 

information is at times incomplete (e.g., length may be missing or recorded as zero) or may be outdated 

(e.g., a vessel may no longer be operating while its status in the database remains “active”). 

Consequently, the information provided by the database should be seen as approximate and as indicative 

of the general characteristics of different populations or classes of vessels that operate in U.S. waters. 

1.4.2. Overview of Vessel Universe

Information is provided in MISLE for a total of 993,863 vessels. Based on information recorded 

in the database, 976,649 of these vessels are presumed currently operational, of which 918,469 vessels 

are identified as U.S.-flagged vessels (referred to as “domestic” vessels in the remainder of the 

section).9,10 Nearly 80 percent of the 918,469 operational domestic vessels recorded in MISLE are 

recreational vessels (722,522 vessels), while 7.6 percent are identified as commercial fishing vessels. 

The remainder of the MISLE universe is composed of other types of nonrecreational vessels 

(10.5 percent) such as freight and tank barges and ships, passenger vessels, and utility vessels, and 

vessels of unspecified service (3 percent). Figure 1.1. presents the MISLE population of operational, 

domestic vessels for all vessel service categories, excluding recreational vessels. While the P.L. 110-299 

 

7

 While the number of recreational vessels recorded in MISLE is high (over 700,000), the database accounts for only a small 

fraction of the 16.9 million recreational vessels estimated to operate in U.S. waters, according to EPA’s Economic Impact 

Analysis of the Recreational Vessel Permit (USEPA, 2008a) and to the National Marine Manufacturers Association’s 

(NMMA’s) 2007 U.S. Recreational Boat Registration Statistics (NMMA, 2009). 8

 Personal communication with U.S. Coast Guard Representative, LCDR Scott Muller, on May 15, 2009. 9

 Approximately 355,000 vessels do not provide a vessel status and 5,000 have an "unknown" status. Following guidance 

from a Coast Guard representative (Source: Personal email communication with Harold Krevait of the U.S. Coast Guard. 

March 13, 2009), EPA assumed that these vessels are currently operational. 10 This count is based on the flag of the vessel. However, the MISLE database records a U.S. hailing port for some vessels 

that are foreign flagged. Additionally, approximately 57,000 vessel records do not identify the vessel flag. EPA assumed that 

these are domestic vessels. 

12 
Chapter 1 – Introduction to Report 

moratorium will generally apply to discharges from the vessel service categories shown in the figure, 

many of the vessels presented in Figure 1.1. are not subject to the P.L. 110-299 permitting moratorium 

since the law is limited to commercial fishing vessels (regardless of size) and other nonrecreational 

vessels 79 feet or less. Approximately one-third of the operational, domestic, nonrecreational vessels are 

commercial fishing vessels. The next largest vessel service category is freight barges, with 

approximately 24 percent of vessels; however, many of these barges may exceed the 79-foot length 

restriction. 

Freight Barge

46,129

24%

Tank Ship

528

0%

Utility Vessel

16,338

8%

Other

96,637

49%

Tank Barge

7,813

4%

Passenger Vessel

22,851

12%

Freight Ship

1,655

1%

Unspecified

29,366

15%

Commercial Fishing Vessel

69,944

35%

Public Vessel, Unclassified

1,323

1%

Source: U. S. Coast Guard, MISLE database, 2009. 

Note; The chart includes all commercial fishing vessels recorded in MISLE (69,944) and all 96,637 other non-recreational vessels, regardless of length.

Figure 1.1. MISLE Population of Operational, Domestic Non-Recreational Vessels by Vessel 

Service11,12 

Table 1.1 further characterizes the vessel population in terms of length greater than or equal to or 

less than 79 feet within each vessel service category. As shown in both Table 1.1 and Figure 1.1., the 

vast majority of vessels contained in MISLE are less than 79 feet in length. For example, nearly 

77 percent of commercial fishing vessels (54,176 vessels out of 69,944) recorded in MISLE have a 

 

11 This figure does not include the 722,522 recreational vessels included in the MISLE population of operational, domestic 

vessels. 

12 Approximately 74,000 vessels have a vessel service indicated as "unclassified", "unknown", or "unspecified" in MISLE. In 

approximately 44,000 of those instances, EPA was able to assign a vessel service for the purpose of this analysis based on 

information provided in other data fields (i.e., using vessel class, vessel type, or vessel subtype information). 

13 
Chapter 1 – Introduction to Report 

length less than 79 feet.13 Vessels less than 79 feet also are a vast majority (94 percent) of the 

recreational vessels. Only the other nonrecreational vessel service category counts a majority of vessels 

79 feet or longer. 

Table 1.1. Population of Operational, Domestic MISLE Vessels by Vessel Length 

Recreational Commercial Fishing Other Non-Recreational Unspecified 

Greater than or Equal to 79 ft 2,256 2,231(2) (3) 54,142 1,991 

Less than 79 ft 676,915 54,176 32,799 15,011 

Zero or Null(1) 43,351 13,537 9,696 12,364 

Total 722,522 69,944 96,637 29,366 

Source: U. S. Coast Guard, MISLE database, 2009 

(1) MISLE indicates a length of zero or the vessel length field is blank. 

(2) A separate estimate provided by U.S. Coast Guard personnel suggests that commercial fishing vessels 79 feet 

long or greater number approximately 1,800 to 1,900 vessels.14

(3) Columns with yellow background represent study vessels. 

 Recreational vessels are generally excluded from many parts of our analysis because a separate 

act (the Clean Boating Act of 2008 (P.L. 110-288)) exempts discharges incidental to the normal 

operation of these vessels from NPDES permitting requirements. The Clean Boating Act defines 

recreational vessels as those that are either 1) manufactured or used primarily for pleasure or 2) leased, 

rented, or chartered to a person for the pleasure of that person. Furthermore, vessels that are subject to 

U.S. Coast Guard inspection and that are either engaged in commercial use or that carry paying 

passengers are not considered recreational vessels under the Clean Boating Act. This definition does not 

necessarily correspond to the service categories used in MISLE to identify recreational versus 

nonrecreational vessels because MISLE categories are based on the type of service the vessel is used for 

rather than original manufacture purpose. There are additional instances in which MISLE may differ 

from Clean Boating Act definitions, making the distinction between vessels listed in the database that 

are within and outside the scope of this study not always clear. For example, certain vessels that would 

appear to fall under the Clean Boating Act definition of recreational vessels because they are described 

as uninspected vessels carrying fewer than 6 passengers are classified as “passenger vessels” in MISLE; 

however, MISLE does not provide further specifications on whether the vessels are leased, rented or 

chartered to a person or whether they carry paying passengers. A second example would include charter 

fishing vessels. Often, these vessels are manufactured or used primarily for pleasure, or leased, rented, 

or chartered to a person for the pleasure of that person. Many are not inspected by the US Coast Guard. 

Charter fishing vessels which are not inspected are exempted from NPDES permitting requirements by 

the Clean Boating Act (P.L. 110-288). Other charter fishing vessels are inspected by the US Coast 

Guard. These inspected, non-recreational vessels are not exempted from NPDES by the Clean Boating 

Act, and are study vessels only if they are less than 79 feet. Since EPA is unable to determine whether 

certain charter fishing vessels are study vessels or Clean Boating Act vessels based on the information in 

MISLE, all charter fishing vessels listed in MISLE are included in the following estimates of study 

vessels. 

 

13 According to a U.S. Coast Guard representative, the overall fraction of commercial fishing vessels that are less than 79 feet 

in length is estimated to be approximately 95 percent (Personal communication with Jack Kemerer, Fishing Vessel Safety 

Program, May 26, 2009). 

14 Personal communication with Jack Kemerer, Fishing Vessel Safety Program, May 26, 2009. 

14 
Chapter 1 – Introduction to Report 

1.4.2.1. Study Vessel Type 

Once commercial, non-fishing vessels longer than 79 feet are removed from the analysis, the 

relative makeup of the study vessels changes. EPA estimates there are between 118,000 and 

140,000 vessels in the United States subject to the permitting moratorium established by P.L. 110-299.15

Figure 1.2. presents the estimated distribution of vessels within the study vessel population by vessel 

service (type). Approximately one-half of these vessels are commercial fishing vessels involved in such 

activities as fish catching (e.g., longliner, shrimper, and trawler), fish processing, fishing tenders, and 

charter fishing. The other one-half are distributed among a variety of vessel classes, including passenger 

vessels (e.g., water taxis, tour boats, harbor cruise ships, dive boats), utility vessels (e.g., tug/tow boats, 

research vessels, offshore supply boats), and freight barges. 

 

15 The range accounts for the exclusion and inclusion, respectively, of other non-recreational vessels for which MISLE does 

not record the length or for which the recorded length is zero. 

15 
Chapter 1 – Introduction to Report 

4,288 67 287 49

15,012

8,876

56,407

18,660

579 -

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

Commercial

Fishing Vessel

Freight Barge

Freight Ship

Passenger

Vessel

Public Vessel,

Unclassified

Tank Barge

Tank Ship

Utility Vessel

Unspecified

Vessel Service

Number of Vessels

Vesels with unspecified length

Vessels less than 79 feet in length

Other non-recreational

69,944

8,016

768

20,953

622 923 179

11,034

27,375

140,000 - Total number of vessels, 

including vessels of unspecified length

118,000 - Number of vessels with 

specified length less than 79 feet

Note: The figure is based on operational, U.S.-flagged commercial fishing vessels (regardless of length) and other nonrecreational vessels 

less than 79 feet in length. 

Commercial fishing vessels also include fish processing vessels and fishing vessels. Passenger vessels include passenger (inspected), 

passenger (uninspected), passenger barge (inspected), passenger barge (uninspected), and passenger ships. Public vessel, unclassified 

includes military and other public service vessels. EPA notes that military vessels are specifically excluded in P.L. 110-299. Utility vessels 

include towing vessels (i.e., tugs), school ships, research vessels/ships, mobile offshore drilling units, offshore vessels, offshore supply 

vessels, oil recovery vessels, and industrial vessels. EPA notes that not all of all the vessels represented in this table are subject to the 

moratorium at all times (e.g., small mobile offshore drilling units when engaged in industrial activity are required to have permits). Freight 

barges include general barges, dry cargo barges, container barges, flat deck barges, and unspecified vessel types that operate in freight 

barge service. Tank barges include bulk liquid (cargo) barges, bulk liquefied gas barges, and unspecified vessel types that operate in tank 

barge service. Some vessel service categories did not fall into one of the listed categories. Therefore, based on the other classification fields 

(class, type, subtype), EPA determined an appropriate service category. 

Source: U. S. Coast Guard, MISLE database, 2009 

Figure 1.2. Number of Study Vessels Recorded in MISLE, by Vessel Service (Type) 

Commercial Fishing Vessels

 As shown in Figure 1.2., approximately 70,000 commercial fishing vessels represent the largest 

category of study vessels. Based on this information, EPA sampled more commercial fishing vessels 

than other nonrecreational vessels less than 79 feet in length (see discussion in Section 2.2.1). According 

to the vessel service categories used by the U.S. Coast Guard in MISLE, “commercial fishing vessels” 

16 
Chapter 1 – Introduction to Report 

are vessels involved in such activities as fish catching (e.g., longliner, shrimper, trawler), fish 

processing, and charter fishing.16 

The U.S. Coast Guard generally describes commercial fishing vessels as including fishing 

vessels, fish tender vessels, and fish processing vessels as follows: 

 Fish processing vessel17 means a vessel that commercially prepares fish or fish products 

other than by gutting, decapitating, gilling, skinning, shucking, icing, freezing, or brine 

chilling. 

 Fish tender vessel means a vessel that commercially supplies, stores, refrigerates, or 

transports fish, fish products, or materials directly related to fishing or the preparation of fish 

to and from a fishing, fish processing, or fish tender vessel or a fish processing facility. 

 Fishing vessel means a vessel that commercially engages in the catching, taking, or 

harvesting of fish or an activity that can reasonably be expected to result in the catching, 

taking, or harvesting of fish. 

While there is some overlap in service use for commercial fishing vessels and other vessel 

categories, such as passenger vessels (e.g., charter fishing), EPA assumed that the categorization used in 

MISLE generally follows the U.S. Coast Guard definition of commercial fishing vessels.18 

Other Nonrecreational Vessels

Excluding the approximately 27,000 “unspecified” vessels shown in Figure 1.2., “passenger 

vessels” have the second highest number of study vessels with approximately 21,000 vessels 

(approximately 19,000 of these vessels have a length recorded as 79 feet or less). These vessels are 

further divided into subtypes according to the types of activities in which they are involved (e.g., diving 

vessels, charter fishing vessels, ferry, harbor cruise vessels, sailing vessels). Approximately 

7,833 vessels are categorized as inspected under 46 CFR (7,753 under part T (small passenger vessels 

under 100 gross tons), 69 vessels under part K (small passenger vessels carrying more than 150 

passengers or with overnight accommodations for more than 49 passengers), and 11 vessels under part H 

(passenger vessels 100 or more gross tons)19). The remaining 13,120 vessels are recorded as uninspected 

passenger vessels.20 

 

16 Several charter fishing vessels are categorized as “commercial fishing vessels” in MISLE even though they are generally 

not considered commercial fishing vessels by the U.S. Coast Guard Fishing Vessel Safety Program. That program considers 

these vessels to be passenger vessels (Source: Personal communication with Jack Kemerer, Fishing Vessel Safety Program, 

May 26, 2009). According to the Coast Guard definition, the key difference between vessels formally classified as 

commercial fishing vessels and recreational vessels or passenger vessels that may be used in fishing activities is whether the 

catch is sold. 

17 The moratorium provided by P.L. 110-299 applies only to discharges incidental to the normal operation of a vessel when 

operating in a capacity as a means of transportation. EPA requires NPDES permits for seafood processing vessel discharges 

when they are engaged in the processing of seafood (an industrial activity). 

18 The MISLE classification also depends on the information provided directly by the vessel owner or operator on the 

application for documentation or renewal (Source: Personal communication with Jack Kemerer, Fishing Vessel Safety 

Program, May 26, 2009). 

19 This last category appears to contain vessels potentially misclassified since their indicated gross tonnage is less than 100 

gross tons. 

20 The definition of passenger vessels used in MISLE is broader than vessels subject to inspection under 46 CFR parts T, K, 

and H. Therefore, depending on how these vessels are operated (e.g., whether they carry paying passengers only or leased, 

17 
Chapter 1 – Introduction to Report 

18 

 

The service category labeled “public vessel, unclassified” accounts for up to 600 study vessels 

(e.g., lighthouse tender vessels, hospital ships, law enforcement vessels, ice breakers). The “utility 

vessels” category covers remaining types of vessels, including tug/tow boats, school ships, research 

vessels/ships, mobile offshore drilling units, offshore vessels, offshore supply vessels, oil recovery 

vessels, and industrial vessels. As many as 11,000 vessels are classified as utility vessels in MISLE.21

Freight barges (4,288 to 8,016 vessels), freight ships (579 to 768 vessels), tank barges (67 to 622 

vessels), and tank ships (49 to 179 vessels) account for the remaining nonrecreational study vessels.22

rented or are chartered to a person for the pleasure of that person), they could fall under the Clean Boating Act definition of

recreational vessels and would therefore be outside the scope of the permitting moratorium. 

21 Some vessel service categories did not fall into one of the listed categories. EPA determined an appropriate service 

category based on information provided in other vessel classification fields (class, type, subtype). 

22 For each range, the minimum value represents the number of vessels for which the length is non null or zero and is less 

than 79 feet while the maximum value represents the total number of vessels when including vessels for which the length is 

unspecified or zero. 
Chapter 1 – Introduction to Report 

1.4.2.2. Vessel Size 

Vessels can be characterized by size according to two metrics: length and gross tons. The two 

metrics are related to each other (gross tonnage is a function of the ship’s enclosed spaces as measured 

to the outside of the hull framing), and Figure 1.3 presents a scatter plot of gross tons and lengths for 

commercial fishing vessels and other nonrecreational vessels obtained from MISLE. In general, most 

nonrecreational vessels in MISLE have a length ranging between 26 and 50 feet, which translates into a 

tonnage generally below 50 gross tons. The 79-foot length threshold for other nonrecreational vessels 

(the criterion for applicability of P.L. 110-299 moratorium) corresponds roughly to a tonnage of 150 

gross tons. In Chapter 6 of this report, EPA uses this information in determining whether certain vessels 

may be subject to regulation under federal law or a binding international obligation of the United States. 

Note: This chart is based on all operational, U.S.-flagged commercial fishing vessels and other nonrecreational vessels, regardless of 

length. 

Source: U. S. Coast Guard, MISLE database, 2009 

Figure 1.3. Relationship Between Vessel Gross Tons and Length 

19 
Chapter 1 – Introduction to Report 

Approximately half of vessels documented in MISLE fall within the 26- to 50-foot-length 

category, they have an average vessel length of 41 feet. Figure 1.4 and Figure 1.5 illustrate the 

distribution of vessel length for commercial fishing vessels and other nonrecreational vessels in terms of 

the vessel count (Figure 1.4) and cumulative distribution (Figure 1.5). In analyzing the cumulative 

distribution of vessels by length (Figure 1.5), tank ships are the only vessel service category with a large 

percentage of vessels longer than 300 feet.23 Several other vessel service categories have a significant 

fraction of vessels above the 79 feet threshold. Steps in the cumulative distribution (Figure 1.5) indicate 

common lengths for certain categories of vessels: freight barges are generally around 200 feet in length, 

while tank barges tend to be 200 feet or 300 feet in length. For almost all other vessel service categories 

(commercial fishing vessels, passenger vessels, utility vessels and unspecified vessels), vessels less than 

79 feet represent the majority of vessels within the overall population. 

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

15406590

115140165190215240265290

Vessel Length (feet)

Number of Vessels

Commercial Fishing Vessel

Freight Barge

Utility Vessel

Freight Ship

UNSPECIFIED

Tank Ship

Tank Barge

Public Vessel, Unclassified

Passenger Vessel

79 feet

Note: This figure is based on operational, U.S.-flagged commercial fishing vessels and all other nonrecreational vessels (no size exclusion). 

Source: U.S. Coast Guard, MISLE database, 2009 

Figure 1.4. Distribution of MISLE Vessels by Length and Vessel Service (Type) 

 

23 Although a large percentage of tank ships are listed as greater than 300 feet long, this accounts for a very small number of 

vessels when compared to the overall universe of vessels in the selected service categories; approximately 300 of the 391 

tank ships that list a vessel length are longer than 300 feet. 

20 
Chapter 1 – Introduction to Report 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

15406590

115140165190215240265290315340365390415440465490

Vessel Length (feet)

Cumulative Fraction

Commercial Fishing Vessel

Freight Barge

Utility Vessel

Freight Ship

UNSPECIFIED

Tank Ship

Tank Barge

Public Vessel, Unclassified

Passenger Vessel

79 feet

500 +

Note: This figure is based on operational, U.S.-flagged commercial fishing vessels and all other nonrecreational vessels (no size exclusion). 

Source: U. S. Coast Guard, MISLE database, 2009

Figure 1.5. Cumulative Distribution of MISLE Vessels by Length and Vessel Service (Type) 

As shown in the two previous figures, there is significant variability in vessel length across 

categories of nonrecreational vessels. Most freight barges reported in MISLE are about 200 feet in 

length and relatively few (10 percent) are under 79 feet in length.24 Hence, most freight barges are not 

subject to the moratorium in P.L. 110-299 and are currently eligible for coverage under the VGP. In 

contrast, the majority of utility vessels (e.g., towing vessels), passenger vessels, and commercial fishing 

vessels overall are less than 79 feet in length. Figure 1.6 shows the distribution of all commercial fishing 

vessels and only nonrecreational vessels less than 79 feet in length by length and vessel service 

(focusing on the study vessels). The majority of commercial fishing vessels are relatively small 

compared to other nonrecreational vessels such as barges or utility vessels, with 70 percent of 

commercial fishing vessels for which the length is specified in MISLE in the 26- to 50-foot range. The 

length of other nonrecreational vessels varies among the subcategories, with as many as 66 percent of 

 

24 Freight barges less than 79 feet in length include a wide range of vessels used for freight barge service, as classified in 

MISLE. These include, for example, barges operated by oil spill response companies or by dredging companies to transfer 

recovered oil or dredged material. 

21 
Chapter 1 – Introduction to Report 

passenger vessels in the 26- to 50-foot range, compared to less than 1 percent of freight barges within 

that same range (most freight barges less than 79 feet in length fall in the 50- to 79-feet range). 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Less than 26 5,631 52 31 1,489 9 36 2 713 5,598

26-50 39,262 214 289 13,496 41 126 23 3,966 8,129

50-79 9,283 4,021 258 3,674 16 124 23 4,196 1,284

79 or more 2,231

Commercial 

Fishing Vessel Freight Barge Freight Ship Passenger 

Vessel

Public Vessel, 

Unclassified Tank Barge Tank Ship Utility Vessel Unspecified

NOT INCLUDED IN SELECTED POPULATION

Note: This figure is based on operational, U.S.-flagged commercial fishing vessels and other nonrecreational vessels less than 79 feet in 

length. 

The length field is not reported or provides a value of zero for approximately 36,000 vessels. 

Source: U. S. Coast Guard, MISLE database, 2009

Figure 1.6. Distribution of Study Vessels by Length (in Feet) and Vessel Service (Type) 

Figure 1.7 presents the distribution of study vessels by gross tons and vessel service. Overall, 

nearly 77 percent of study vessels are less than 50 gross tons, while the remaining vessels generally fall 

within the 50- to 300-gross-tons range. Very few vessels (less than 1 percent) within the selected vessel 

population are greater than 300 gross tons. Note that some vessel service categories appear 

underrepresented because the gross tons field is blank or is listed as zero in MISLE for approximately 

56,000 vessels. 

22 
Chapter 1 – Introduction to Report 

 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Less than 50 36,650 337 409 15,190 35 161 36 4,398 7,474

50-100 4,599 148 119 1,751 5 75 5 2,469 489

100-300 4,048 3,734 26 59 3 24 4 1,356 159

300-500 148 7 1 2 1 4 7

500-1000 158 10 1 4 1 2

1,000 or more 133 1 5 9 2 10

Commercial 

Fishing Vessel Freight Barge Freight Ship Passenger Vessel

Public Vessel, 

Unclassified Tank Barge Tank Ship Utility Vessel Unspecified

Figure insert: Distribution of Study Vessels

 by Gross Tons and Vessel Service; for Size Categories 

 representing 10 Percent or Less of Vessels 

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

Commercial

Fishing Vessel

Freight Barge Freight Ship Passenger

Vessel

Public Vessel,

Unclassified

Tank Barge Tank Ship Utility Vessel Unspecified

Note: This chart is based on operational, U.S.-flagged commercial fishing vessels and other nonrecreational vessels less than 79 feet in 

length. 

The gross tons field is not reported or provides a value of zero for approximately 56,000 vessels. 

Source: U. S. Coast Guard, MISLE database, 2009

Figure 1.7. Distribution of Study Vessels by Gross Tons and Vessel Service (for which gross ton 

data are given in MSLE) 

To select specific vessel classes for sampling, EPA first developed a list of commercial vessel 

classes based on published information and industry experience. Next, EPA eliminated those vessel 

classes believed to consist of vessels greater than 79 feet in length, with the exception of commercial 

fishing vessels. Examples of vessel classes eliminated because of their size include cable laying ships, 

cruise ships, large ferries, and oil and petroleum tankers. Next, EPA eliminated vessel classes not 

subject to VGP permitting, including stationary seafood processing vessels and vessels that can be 

secured to the ocean floor for mineral or oil exploration (the CWA regulations separately require 

NPDES permits for industrial operations onboard vessels). After screening out these vessel classes, EPA 

selected a subset of priority vessel classes to study, including commercial fishing boats, tug and tow 

boats, water taxis, tour boats, recreational vessels used for nonrecreational purposes, and industrial 

23 
Chapter 1 – Introduction to Report 

support boats less than 79 feet in length. EPA selected these vessel classes because they provide a cross 

section of discharges and a broad range of potential pollutants. 

1.4.2.3. Additional Vessel Characteristic Information 

Other vessel characteristics such as vessel age and engine power (horsepower ahead) likely 

influence the characteristics and the volume of many vessel discharges. Intuitively, where a vessel is 

located and operated can determine the impacts. Additionally, where there are more vessels, there is a 

greater likelihood of cumulative impacts (e.g., where there are more vessels, there will be a greater 

impact from vessel discharges). 

Appendix B presents additional vessel characteristic information, including summaries of vessel 

subtypes, the hailing port of domestically flagged vessels, and information on construction and 

propulsion of these vessels, including the vessel age and horsepower ahead. Appendix B also discusses 

limitations in using the MISLE data. Appendix B lists the most common subtypes of vessel within each 

vessel type. For example, towing vessels are the most common type of utility vessel. Appendix B also 

shows where concentrations of vessel activities occur and what vessels are most predominant in those 

assemblages. For example, the hailing port of New Orleans has the most registered vessels, including 

significant numbers of commercial fishing vessels and other nonrecreational vessels. Finally, Appendix 

B shows that most study vessels are relatively old, with the majority of them being more than 25 years 

old. These analyses helped EPA qualitatively and quantitatively analyze the cumulative impact of many 

vessels’ discharges (see Chapter 4 of this report), and to put the numbers and locations of study vessels 

into perspective relative to other vessels, such as recreational vessels and other non-study vessels (e.g., 

nonrecreational, noncommercial vessels greater than 79 feet in length). 

1.5. DISCHARGES FROM VESSELS 

EPA developed a substantial list of discharges from vessels and pollutants of concern in each of 

those discharges during the development and issuance process of the VGP in 2008. Starting with this 

list, EPA developed a subset of discharges prevalent on fishing vessels and nonrecreational vessels less 

than 79 feet in length that are expected to have pollutants of concern. The subset of discharges that EPA 

selected included: bilgewater, deck washdown and runoff, propulsion engine effluent, generator engine 

effluent, firemain systems, fish hold effluent, fish hold cleaning effluent, graywater, and shaft packing 

gland effluent. While EPA did not sample antifouling hull-coating leachate, this discharge is discussed 

as well because this is a significant discharge from many vessels and has been documented to cause 

water quality impacts (see Section 3.2.8). 

EPA recognizes that there are additional discharges25 that also sometimes are present on study 

vessels. Some of these were not conducive to sampling, such as cathodic protection, underwater ship 

husbandry, and oil-to-sea interfaces. Some discharges are generally combined with other discharges and 

 

25 EPA lists many discharges and descriptions of those discharges in the VGP and the accompanying fact sheet. Due to the 

timeframe and resource limitations of this study, EPA chose to focus on the nine discharges that were a) conducive to 

sampling and b) most likely to cause or contribute to impacts to human health, welfare, or the environment. 

24 
Chapter 1 – Introduction to Report 

are not typically available for independent sampling. An example of this is refrigeration system 

condensate that is drained to the bilge. Other discharges are not expected to be commonly generated on 

commercial fishing vessels or nonrecreational vessels less than 79 feet in length. These discharges are 

typically associated with larger vessels, such as those covered by the VGP, and were not sampled for in 

this study due to resource limitations. Some examples include aqueous film-forming foam, distillation 

and reverse osmosis brine, exhaust gas scrubber effluent, elevator pit effluent, and boiler/economizer 

blowdown. A detailed discussion on the discharges EPA decided not to sample is provided in Chapter 2. 

1.5.1. Bilgewater

Bilgewater is defined as the water that collects in the bottom of a vessel’s hull. This includes 

water from rough seas, rain, minor leaks (designed or accidental) in the hull or stuffing box, condensate 

from various types of equipment, spills onboard the vessel, and leaks from pumps and seals. Bilgewater 

can be found on almost every vessel; if too much water accumulates, it could threaten the safety and 

stability of the vessel. For example, the U.S. Coast Guard requires that certain commercial fishing 

vessels and fish-processing vessels have automated bilge pumping systems as part of their basic safety 

features (46 CFR Part 28.255). 

A number of oily and non-oily wastewater sources sometimes drain intentionally or 

unintentionally into the bilge. Oily wastewater sources include oil, fuel, and antifreeze leaks from engine 

and machinery operation and maintenance. To prevent floating oils typically found in bilgewater from 

being discharged overboard, vessels can either use oil-adsorbent pads in the bilge compartment or pump 

the bilgewater through a properly operating oil-water separation system or oil absorbent filter prior to 

overboard discharge. 

Non-oily wastewater sources include non-oily leaks from engine and machinery operation and 

maintenance and various condensates. Vessels can have numerous sources of non-oily machinery 

wastewater, including chilled water condensate drains, fresh- and saltwater pump drains, potable water 

tank overflows, and leaks from propulsion shaft seals. Large vessels typically have separate systems to 

collect non-oily machinery wastewater in dedicated drip pans, funnels, and deck drains for subsequent 

direct discharge. Small vessels can also generate non-oily machinery wastewater; however, these 

wastewaters likely drain into the bilge. 

1.5.2. Deck Washdown and Deck Runoff 

Deck washdowns are typically performed to prevent slip and fall hazards; to prevent dirt, grit, or 

other materials from harming the integrity of the deck surface; or to clean the deck after pulling in a 

catch or unloading cargo. Deck washdown is typically performed using hoses and mops that move the 

deck washdown water and cleaning agents (if any) to the scuppers through which the water is discharged 

overboard. Deck cleaning often occurs while the vessel is underway but is also performed pierside, 

generally after loading or unloading catch or cargo. 

Deck runoff is typically related to either precipitation or surface water spray that lands on the 

deck and flows to the scuppers where it is discharged overboard. Operators of the vessel do not have 

25 
Chapter 1 – Introduction to Report 

Deck Washdown Activity of a Water Taxi (left) and a Towing and 

Salvage Vessel (right). 

control over the volume of discharge related to precipitation events or sea sprays, but they can minimize 

the pollutants carried by the runoff by utilizing appropriate maintenance practices. 

Deck washdown and deck runoff have the potential to contain a variety of pollutants, including 

oil and grease, nutrients, solids, metals, detergents, and solvents. Some or all of these pollutants could be 

introduced to the deck from shipboard activities, storage of material on the deck, maintenance activities, 

and the decking material itself. 

 

1.5.3. Engine Effluent

Engines found on commercial vessels are typically used for two purposes: propulsion and 

electricity generation. Engines used for vessel propulsion can be either outboard or inboard engines. 

Outboard engines are self-contained units designed to be mounted outside the vessel hull at the stern 

(rear) of the vessel. Inboard engines are enclosed within the hull of the vessel, usually connected to a 

propulsion screw by a drive shaft. Outboard engines are typically fueled by gasoline, while inboard 

motors can use either gasoline or diesel fuel. Gasoline or diesel engines can be either two stroke, which 

require small amounts of oil to be mixed with the fuel to create a mixture that both lubricates and 

provides combustion, or four stroke, which have separate lubrication systems. 

All combustion engines require cooling systems to remove excess heat. Direct-cooled marine 

engines draw raw water (either freshwater or seawater in which the vessel is floating) into the engine 

and rely on the raw water to absorb the heat directly from the engine. Biocides sometimes are added to 

the raw water to prevent biofouling of the heat exchange system (biofouling prevention). Indirect-cooled 

marine engines use an enclosed cooling system that requires circulation of a freshwater-coolant solution 

through the engine to absorb heat. The coolant solution passes through a closed heat exchanger where 

the raw water absorbs the heat from the coolant solution and is then discharged. 

Vessels also use keel-cooling systems for indirectly cooling marine engines. A keel cooler is 

essentially a heat exchanger mounted outside the vessel's hull beneath the waterline. Hot water from the 

26 
Chapter 1 – Introduction to Report 

marine engines is pumped through the keel cooler, which is in constant contact with the seawater. This 

closed-circuit cooling system eliminates the need for an inboard heat exchanger, raw water pumps, and 

strainers and does not result in a discharge. 

Some engines also use water to cool and quiet their exhaust, referred to as boat engine wet 

exhaust. These engines inject spent cooling water from the engine into the exhaust stream, which results 

in some of the gaseous and solid components of the exhaust being entrained into the cooling water 

discharge. 

Vessels that require significant lighting or have electrical equipment, such as appliances and/or 

electric motors, are likely equipped with engines used for electricity generation. Electrical generators on 

these vessels are typically powered by diesel engines. The size of the electrical generators depends on 

the electrical load requirements for the vessel, but could range from small generators used to power 

navigation equipment and galley appliances to large generators used to power electric motors on deck 

winches and cranes. Similar to vessel engines, electrical generators will require direct or indirect 

cooling. 

Collecting a Sample of Engine Effluent at Full Speed. 

27 
Chapter 1 – Introduction to Report 

Inboard Engine (left) and Outboard Engine (right) 

1.5.4. Firemain Systems

Some vessels are equipped with firemain systems to supply water for firefighting and to supply 

water to other vessel systems. Vessels use either “wet type” or “dry type” firemain systems. The wet 

type firemain piping is normally filled with water. Wet type systems are particularly used on vessels 

where the firemain water is used frequently, typically for maintenance activities such as deck 

washdown. In a dry type system, the piping is normally empty. Water is only introduced to the pipes 

when actual firefighting takes place, or for testing or training. 

Aqueous film-forming foam (AFFF) can also be used on vessels as a fire suppression agent. 

AFFFs are a combination of fluorochemical surfactants, hydrocarbon surfactants, and solvents (Koetter, 

2008) that are injected into the water stream of a fire hose. These film-forming agents are capable of 

forming water solution films on the surface of flammable liquids, separating the fuel from the air 

(oxygen). Systems that use AFFFs do not appear to be common on smaller vessels. 

Firemain System on a Fire Boat. 

28 
Chapter 1 – Introduction to Report 

Fire Boat. 

1.5.5. Fish Hold and Fish Hold Cleaning Effluent (Refrigerated Seawater Discharge or Fish 

Ice Slurry Discharge)

Commercial fishing vessels utilize different methods to keep seafood fresh after it is caught. 

Most seafood is either dead when brought onboard or is killed shortly thereafter, before being stored in a 

refrigerated seawater holding tank, with the exception of certain shellfish (e.g., crab, lobster), which 

must be kept alive. The two most common methods of cooling seawater are by mechanical refrigeration 

or by adding ice. Mechanical refrigeration is common on tenders, purse seiners, and trawlers, while 

chipped and slurry ice tanks are more common on trollers, longliners, gillnetters, and some trawlers. 

For vessels with refrigerated seawater tanks, fish are typically extracted using a vacuum system 

that removes both the fish and refrigerated seawater simultaneously. Any excess refrigerated seawater 

that is not required to assist in fish extraction is pumped overboard pierside. Vessels that use chipped or 

slurry ice generally remove the seafood and then discharge the spent ice overboard pier side. 

Occasionally, vessels that store their catch in ice slurry also use vacuum filtration systems (e.g., some 

shrimping boats in the Gulf of Mexico). These discharges often contain pollutants generated by the 

catch, such as biological wastes. 

Tanks used to keep lobster and crab catch alive pump surrounding water into the tank constantly 

to maintain the highest water quality possible. The flow rate through these systems results in a nearly 

continuous discharge of fish hold effluent. Because the majority of the seafood product remains alive, 

however, there is little biological decay or degradation in the tank. Furthermore, because these tanks 

have reasonably rapid flushing times and a continuous discharge, there is a little accumulation of 

pollutants. 

Fish holds are also often cleaned or disinfected by vessel crews between catches. To rinse the 

tank, vessel crews use either municipal water from the pier or dock or they pump water from the 

surrounding ambient water. Cleaning may simply involve rinsing the tanks with this water, or crews 

29 
Chapter 1 – Introduction to Report 

Shoveling Fish Hold Ice Overboard From Ice Tank. 

sometimes add detergents or disinfectants. Crews also often use scrub brushes to clean the walls and 

floor of the fish hold to maximize the removal of organic material. Fish hold cleaning effluent is a 

combination of residual fish hold water and ambient or municipal water and often contains soaps or 

detergents. 

View of a Full Refrigerated Seawater Tank. 

30 
Chapter 1 – Introduction to Report 

1.5.6. Graywater

Graywater is generated onboard vessels from domestic activities such as dish washing, food 

preparation, laundry, and bathing. Graywater is discharged through either a single discharge port from a 

collection system or through multiple, separate discharge ports for each graywater source (e.g., sink, 

shower, washing machine). Graywater discharge is intermittent and occurs only when the specific 

activity is performed. Most graywater processes use onboard potable water (service water). 

Smaller vessels can sometimes not generate any graywater. Many of these vessels are for day use 

and do not provide any overnight quarters or heads (toilets). Smaller vessels that do generate graywater 

(e.g., those that have accommodations, sinks, or showers) generally discharge graywater directly 

overboard via ports typically located above the waterline. Most larger vessels used for overnight or 

multiday travel have numerous graywater sources, including showers, bathroom and kitchen sinks, and 

laundry. On these vessels, graywater discharges overboard by draining through gravity to either a 

discharge port above the water line or to a small collection tank located in the vessel hull, where it is 

immediately pumped to a discharge port above the waterline. Other vessels can collect their graywater 

and treat it along with sewage in Marine Sanitation Devices (MSDs). 

Collecting Graywater (Shower) Effluent. 

Typical pollutants found in graywater often include metals, pathogens, total suspended solids, 

biochemical oxygen demand, chemical oxygen demand, oil, grease, ammonia, nitrogen, and phosphates. 

Graywater does not include sewage, or “blackwater”, which is exclusively human waste from toilets and 

urinals. Sewage is regulated under Section 312 of the Clean Water Act and 40 CFR Part 140 (see 

Chapter 6 of this report for further discussion). 

1.5.7. Shaft Packing Gland Effluent

For vessels with propeller shafts, a packing gland, or stuffing box, is used to provide a seal 

around a propeller shaft at the point where it exits a boat's hull underwater. This is a common method 

for preventing water from entering the hull while still allowing the propeller shaft to turn. In a 

conventional packing gland, the seal itself is provided by packing rings made of greased flax that is 

31 
Chapter 1 – Introduction to Report 

32 

packed or wound tightly around the propeller shaft and compressed in place with a threaded nut and 

spacer. The gland can also be fitted with an opening for periodic insertion of grease between the rings, 

and sometimes includes a small grease reservoir. 

A packing gland packed with flax rings is designed to leak a small amount of water—a few 

drops per minute—to provide lubrication when the shaft is turning. Water that leaks through the seal 

sometimes drips into a non segregated bilge or collects in a segregated area to avoid contact with oily 

wastewaters. In the case of a segregated area, the water that collects (referred to as shaft packing gland 

effluent) is automatically pumped overboard when levels reach a preset depth to prevent overflow. 

1.5.8. Antifouling Hull Coatings26

Vessel hulls are often coated with antifouling compounds to prohibit the attachment and growth 

of aquatic life. Coatings are formulated for different conditions and purposes, and many contain 

biocides. Those that contain biocides prevent the attachment of aquatic organisms to the hull by 

continuously leaching substances into the surrounding water that are toxic to aquatic life. While a 

variety of different biocides are used, the most commonly used is copper. Hull cleaning activities often 

can cause additional releases of biocides, particularly if hulls are cleaned within the first 90 days 

following application of the antifouling coating. 

A second metal-based biocide is organotin-based, typically tributyltin (TBT), which was 

historically applied to vessel hulls. TBT and other organotins cause deformities in aquatic life, including 

defects that disrupt or prevent reproduction. TBT and other organotins are also stable and persistent, 

resisting natural degradation in water bodies. As discussed in Chapter 6 of this report, the use of TBTs 

and other organotins as biocides has been phased out on all vessels by domestic law and international 

treaty. 

1.6. POLLUTANTS POTENTIALLY FOUND IN VESSEL DISCHARGES

EPA developed groupings of pollutants of concern in the issuance process of the VGP in 2008. EPA 

recognizes that while some discharges from all sizes of vessels are essentially the same, many will vary 

due to the specific machinery and activities conducted on these vessels. EPA used slightly different 

groupings of the pollutants from the discharges sampled for this report to address differences from the 

discharges covered by the VGP. The pollutants and constituents of concern are broken down into the 

following groups: classical pollutants, nutrients, pathogen indicators, metals, volatile organic 

compounds (VOCs), semivolatile organic compounds (SVOCs), and nonylphenols. Not all pollutants are 

expected to be found in each discharge. For each discharge, EPA attempted to identify which pollutant 

groups are of concern.

 

26 Though antifoulant hull coatings are present on some study vessels, particularly those operating in areas where there is a 

significant potential for fouling, it was not feasible to sample discharges from these coatings for this study (see Chapter 2 for 

further discussion). 
Chapter 1 – Introduction to Report 

1.6.1. Classical Pollutants

For purposes of this report, EPA uses the term “classical pollutants” for the following 14 

pollutants: temperature; conductivity; salinity; turbidity; dissolved oxygen; total suspended solids (TSS); 

biochemical oxygen demand (BOD); chemical oxygen demand (COD); total organic carbon (TOC); oil 

and grease; pH; sulfide; and total residual chlorine (TRC). These include the CWA conventional 

pollutants plus other common pollutants that are of general concern in a wide variety of contexts. 

Temperature changes can directly affect aquatic organisms by altering their metabolism, ability 

to survive, and ability to reproduce effectively. Increases in temperature are frequently linked to 

acceleration in the biodegradation of organic material in a water body, which increases the demand for 

dissolved oxygen and can stress local aquatic communities. Thermal impacts from vessel discharges are 

generally much smaller than those from traditional point sources, and the vessel discharge with the 

greatest potential to alter receiving water temperature is engine cooling water. 

Conductivity and salinity measurements are related to ionic strength and can indicate what 

specific ions are present in water or wastewater. Conductivity is a measure of the ability of water to pass 

an electrical current. Conductivity in water is affected by the presence of inorganic dissolved solids (or 

ions). Organic compounds like oil, phenol, alcohol, and sugar do not conduct electrical current very well 

and therefore have a low conductivity when in water. Conductivity is also affected by temperature; the 

warmer the water, the higher the conductivity. Salinity is a measure of the mass of dissolved salts (ions) 

in solution. Ions commonly found in water include calcium, magnesium, potassium, and sodium cations 

and bicarbonate, carbonate, chloride, nitrate, and sulfate anions. The average ocean salinity is 

approximately 35 parts per thousand (ppt), while freshwater salinity is generally less than 0.5 ppt. The 

salinity of brackish water, such as estuaries, is between 0.5 ppt and 17 ppt. Conductivity is a good 

measure of salinity in water and vice versa. 

Both turbidity and TSS are assessments of the amount of suspended solids present in the water 

column. Turbidity is an indicator of water clarity, measuring how much the material suspended in water 

decreases the passage of light through the water. Higher turbidity increases water temperatures because 

suspended particles absorb more heat. Suspended materials, also measured as the mass of TSS, can clog 

fish gills, reducing resistance to disease in fish, lowering growth rates, and affecting egg and larval 

development. As the particles settle, they can smother fish eggs and benthic macroinvertebrates on the 

bottom substrate. Vessel discharges with relatively high turbidity and TSS concentrations include fish 

hold effluent, bilgewater, graywater, and deck washdown. 

The oxygen content of water or wastewater is measured in its dissolved form as dissolved 

oxygen (DO). Low DO levels (hypoxia) can impair animal growth or reproduction, and the complete 

lack of oxygen (anoxia) will kill aquatic organisms. Organic material found in vessel discharges (e.g., 

fish waste, bilgewater, graywater) that are easily biodegraded will result in depressed DO concentrations 

in ambient receiving waters. The ability of the organic material in vessel discharges to biodegrade and 

depress oxygen levels is measured as either BOD or COD. BOD measures the amount of oxygen used 

by naturally occurring microorganisms to metabolize the organic material in the vessel discharge, while 

COD measures the oxygen needed to chemically oxidize the organic material in the vessel discharge. If 

33 
Chapter 1 – Introduction to Report 

there is a large quantity of organic waste in water, there will also be a lot of bacteria present working to 

decompose this waste. In this case, the demand for oxygen will be high (due to all the bacteria), so the 

BOD level will be high. COD levels can often be correlated with BOD levels, though they are generally 

higher because the measurement examines chemicals that are both biologically and chemically oxidized. 

As the waste is consumed or dispersed through the water, BOD levels will begin to decline. 

Oil and grease are other known components of vessel discharges with potentially harmful 

impacts to humans and to aquatic life. Oil and grease are measured using hexane extractable material 

(HEM) and silica gel treated (SGT)-HEM. Vessels sometimes discharge oil, including lubricating oils, 

hydraulic oils, and vegetable or organic oils, in everyday operation. Oils produce a visible slick or 

sheen27 on the water surface, which decreases natural oxygen transfer, resulting in depressed DO 

concentrations. Also, oils might contain heavy metals and SVOCs, which can bioaccumulate in fish, 

birds, marine mammals, and ultimately humans. Bilgewater, fish hold effluent (fish oils), and graywater 

(galley wastewater) are the vessel discharges most likely to contain oil and grease. 

The term pH is used to indicate the alkalinity or acidity of a substance as ranked on a scale from 

1.0 to 14.0. Substances with lower pH (i.e., less than 7) are acidic, while substances with higher pH (i.e., 

greater than 7) are basic. pH affects many chemical and biological processes in the water. The largest 

variety of aquatic animals prefers a range of 6.5 to 8.0. pH outside this range can reduce diversity 

because it stresses the physiological systems of most organisms. Low pH can allow toxic elements and 

compounds to become mobile and “available” for uptake by aquatic plants and animals. This can 

produce conditions that are toxic to aquatic life, particularly sensitive species. Many vessel-cleaning 

wastewaters can be either acidic (e.g., metal cleaners and tub, toilet, and sink cleaners) or basic (e.g., 

degreasers). 

Sulfide is a strong reducing agent typically generated during anaerobic decomposition of organic 

materials. Sulfides are naturally present in groundwater as a result of leaching from sulfur-containing 

mineral deposits. Surface water does not usually contain high sulfide concentrations. Sulfide is a 

pollutant that is commonly elevated in water distribution systems as well as sewers. Sulfur-reducing 

bacteria, which use sulfur as an energy source, are believed to be the primary producers of large 

quantities of hydrogen sulfide. Ecologically, these bacteria are common in anaerobic environments (e.g., 

plumbing systems). For vessels, possible sources of sulfide include trace constituents in the fuel, 

products of incomplete combustion, or formations in anaerobic systems onboard the vessel. Sulfide 

generated from anaerobic decomposition is suspected in graywater, bilgewater, and fish holds. Sulfide 

may also be formed during fuel combustion in a vessel’s engine. Sulfide, typically found as hydrogen 

sulfide, poses a potential long-term hazard to aquatic life (USEPA, 1986b) at low concentrations. 

Chlorine is commonly used as a disinfectant in wastewater and drinking water. Chlorine, 

measured as TRC, though toxic to humans at high concentrations, is of much greater concern to aquatic 

species, which can experience respiratory problems, hemorrhaging, and acute mortality. TRC is present 

in potable water supplies, and consequently, any vessel systems that use potable water could potentially 

 

27 Visible slick or sheen means a “silvery” or “metallic” sheen, gloss, or increased reflectivity; visual color; iridescence, or oil slick on the 

surface (58 FR 12507).

34 
Chapter 1 – Introduction to Report 

discharge TRC while conducting graywater activities and deck washing. Chlorine bleach can also used 

as a disinfectant in cleaning activities, such as cleaning the fish hold, general vessel cleaning, and 

laundry.

Measuring Total Residual Chlorine Immediately 

After Sample is Taken. 

1.6.2. Nutrients 

Nutrients, including nitrogen, phosphorus, and numerous micronutrients, are constituents of 

vessel discharges. Though traditionally associated with discharges from sewage treatment facilities and 

runoff from agricultural and urban stormwater sources, small quantities of nutrients from vessels are 

discharged from deck runoff, graywater, bilgewater, and fish hold tanks, among other sources. Although 

outside the scope of this report, sewage discharge (blackwater) is likely one of the primary sources of 

nutrients from vessels. 

When excessive amounts of phosphorus and nitrogen are added to the water, algae and aquatic 

plants can be produced in large quantities and cause eutrophication of lakes or ponds. Eutrophication is a 

natural process whereby primary producers (algae and aquatic plants) exhibit extreme growth due to 

increased nutrient loading. Eutrophication can be greatly accelerated by human activities that increase 

the rate at which nutrients enter the water. Increased nutrient discharges from human sources are a major 

source of water quality degradation throughout the United States. 

Total nitrogen is a measure of all the various forms of nitrogen (nitrate, nitrite, and ammonia) 

that are found in a water sample. Nitrification is the biological oxidation of nitrogen compounds in both 

water and soil: ammonia is oxidized to nitrite (via Nitrosomas bacteria) and further oxidized to nitrate 

via Nitrobacter bacteria. Nitrite and ammonia are relatively toxic forms of nitrogen, while nitrate is 

relatively nontoxic. Nitrogen in natural waters is usually found in the form of nitrate. 

Phosphorus can be measured in either the particulate phase or the dissolved phase. Particulate 

matter includes living and dead plankton, precipitates of phosphorus, phosphorus adsorbed to 

particulates, and amorphous phosphorus. The dissolved phase includes inorganic phosphorus and 

35 
Chapter 1 – Introduction to Report 

organic phosphorus. Phosphorus in natural waters is usually found in the form of phosphates. 

Phosphates can be in inorganic form (including orthophosphates and polyphosphates) or organic form 

(organically bound phosphates). 

1.6.3. Pathogen Indicators

Pathogens are microbes that cause disease. They include a few types of bacteria, viruses, 

protozoa, and other organisms. Bacteria associated with human and animal waste (e.g., total and fecal 

coliforms, E. coli, enterococci) are often monitored in water and wastewater, and the detection of these 

organisms can be a reliable indicator that other dangerous pathogens might be present. Pathogens are 

often found in discharges from vessels, particularly in vessel sewage and graywater. 

1.6.4. Metals

Metals are a diverse group of pollutants, many of which are toxic to aquatic life and humans. 

While some metals, including copper, nickel, and zinc, are known to be essential to organism function, 

many others, including thallium and arsenic, are nonessential and/or are known to have only adverse 

impacts. Even essential metals can do serious damage to organism function in sufficiently elevated 

concentrations. Adverse impacts can include impaired organ function, impaired reproduction, birth 

defects, and at extreme concentrations, acute mortality. For example, copper can inhibit photosynthesis 

in plants and interfere with enzyme function in both plants and animals in concentrations as low as 4 

μg/l. Additionally, through a process known as bioaccumulation, metals can accumulate in predator 

organisms further up the food chain, including commercially harvested fish species. 

The toxic potential of a metal depends on its bioavailability in a given aquatic environment. A 

metal’s bioavailability is determined by the characteristics of the surrounding environment (e.g., 

temperature, pH, salinity, TOC) and the species of the affected organism. The environmental conditions 

determine a metal’s tendency to either adsorb to suspended organic matter and clay minerals or to 

precipitate out of solution and settle to the sediments. Benthic organisms can bioaccumulate metals by 

consuming metal-enriched sediments and suspended particles or by uptaking ambient water containing 

the dissolved form of the metal. 

Vessel discharges can contain a variety of metal constituents, which can come from a variety of 

onboard sources. Graywater, bilgewater, and firemain systems have been shown to contain numerous 

metals, the exact constituents of which vary depending on onboard activities and the materials used in 

the construction of the vessel. Other metals, such as copper, are known to leach from the antifoulant 

coatings on vessel hulls and can cause exceedances of water quality standards. 

1.6.5. Volatile and Semivolatile Organic Compounds 

A variety of organic compounds have been found in vessel discharges, many of which are known 

to have a broad array of adverse impacts on aquatic species and human health. For this study, EPA 

measured VOCs and SVOCs, which can dissolve other substances and evaporate readily at room 

temperature and atmospheric pressure. These carbon-containing compounds include a wide range of 

36 
Chapter 1 – Introduction to Report 

chemicals, such as aldehydes, ketones, and hydrocarbons, and are present in oily materials such as 

gasoline, motor oil, engine coolants, and lubricants used on vessels. VOCs such as benzene, which is 

found in fuel, have acute hematological toxicity (ATSDR, 2007) and many SVOCs such as 

benzo(a)pyrene are persistent, bioaccumulative, and toxic compounds. 

EPA measured VOCs and SVOCs in vessel discharges from engines, bilges, and firemains for 

this study. The most significant rates and levels of detection were phthalates (plasticizers added to 

plastics to make them flexible) and components of or products of incomplete combustion of oil and fuel. 

For example, VOCs and SVOCs detected in engine effluent included multiple polycyclic aromatic 

hydrocarbons (PAHs), straight-chain hydrocarbons, phenol and methyl phenols, trimethylbenzene, 

phthalates, and the volatile constituents of fuel, commonly referred to as “BTEX” (benzene, toluene, 

ethylbenzene, xylene). Many of these compounds are known to cause adverse impacts on aquatic species 

and human health. 

1.6.6. Nonylphenols

The general term nonylphenols in this report represents two distinct subsets of the broader family 

of alkylphenols that are commonly used in many products such as liquid detergents and soaps. They can 

degrade to total nonylphenol, or NP, which is toxic to aquatic life. There are different types of 

alkylphenols, such as nonylphenol polyethoxylates (NPEOs) and octylphenol polyethoxylates (OPEOs). 

Because NPEOs and OPEOs are in the same family, they have similar chemical properties. These two 

distinct subsets of alkylphenols (nonylphenols and the closely related octylphenols) exist in these and 

other commercial products as mixtures of isomers (polyethoxylates) of different length chains. Different 

isomers are distinguished by length of the branched alkyl side chain. The longer chain nonylphenol 

polyethoxylates (of which there are 18 isomers distinguished by number, e.g., NP18EO) and octylphenol 

polyethoxylates (of which there are 12 isomers, e.g., OP12EO) eventually will degrade in the 

environment to isomers with shorter chained ethoxylate groups and ultimately, total nonylphenol (NP), 

which, as discussed above, is toxic to aquatic life. In general, the hydrophobicity, persistence, and 

toxicity of the substance all increase as the ethoxylate chain becomes shorter. The short-chained isomers 

may be quite persistent once they are buried in the sediment, and bottom-feeding fish can be 

significantly exposed to these persistent and toxic compounds. Long- and short-chain NPEOs and 

OPEOs are expected to be found in several vessel discharges, including graywater, deck washing 

wastewater, and bilgewater. 

1.7. CHAPTER CONCLUSIONS

The information summarized and referenced in this chapter provides an introduction to the study 

vessel universe. It describes the universe of study vessels, the types of discharges generally thought to 

originate from those vessels, and the types of pollutants or other constituents generally found in those 

vessel discharges. It also references information contained in Appendix B of this report, which provides 

more detailed information on the study vessel universe, such as vessel locations and characteristics. EPA 

estimates that there are between 118,000 and 140,000 vessels in the United States subject to the NPDES 

permitting moratorium established by P.L. 110-299. This chapter concludes that commercial fishing 

37 
Chapter 1 – Introduction to Report 

38 

vessels are the most common type of study vessels, although there are significant numbers of other 

commercial study vessels. 

The information contained in this chapter helped inform EPA’s decisions of which discharges to 

sample and the relative importance of each discharge (see Chapters 3, 4, and 5 for additional 

discussion). Based on EPA’s experience gained during the VGP process, the Agency believes 

bilgewater, graywater, deck washdown, fish hold, engine effluent, and antifouling hull coating leachate 

are the primary vessel discharges that could impact surface water quality. Pollutants in these discharges 

might include metals, organics, nonylphenols, nutrients, oxygen depleting compounds, and pathogens. 

The following chapters of this report present the methodology EPA used to characterize discharges from 

vessels subject to the NPDES permitting moratorium, the results of that characterization, and the 

potential environmental impacts to ambient waters that could be caused by these discharges. 
Chapter 2 – Study Design 

CHAPTER 2

STUDY DESIGN 

This chapter documents the methodology that EPA used to conduct this study of 

discharges incidental to normal operation of study vessels. It describes the steps EPA took to 

collect information on the nature and potential impacts of vessel discharges. 

2.1 DATA SOURCES

EPA collected data from a variety of sources, including existing data from other EPA 

data collection efforts, meetings and telephone contacts with trade association representatives, 

vessel visits and sampling, literature reviews, and other governmental data sources. Each of these 

data sources is discussed below. 

2.1.1 Existing EPA Data Sources

A significant source of existing data regarding vessel discharges is EPA’s administrative 

record supporting EPA’s 2008 Vessel General Permit (VGP). The administrative record is a 

collection of all materials EPA considered in developing the VGP, including supporting 

documents, references, and comments received on the proposed VGP. As a first step in 

conducting this study, EPA reviewed these existing data sources to determine whether and to 

what extent the data and information from these sources could be used to satisfy the study 

objectives. This review also identified data and information gaps for EPA to target for additional 

data collection efforts. In general, these existing data sources provided useful information 

regarding the types of vessel discharges generated by vessel class, as well as the shipboard 

processes that contribute to their generation; however, the existing data sources contained little 

or no information regarding the nature, composition, and volume of discharges. 

Other existing data sources evaluated for this study included supporting documents and 

other materials from EPA’s Uniform National Discharge Standards (UNDS) (USEPA, 1999) and 

cruise ship discharges (USEPA, 2008c) programs. These sources, which pertain to armed forces 

vessels and large cruise ships, respectively, have limited applicability to commercial fishing 

vessels and nonrecreational vessels less than 79 feet in length; however, these data sources did 

provide supplemental information regarding shipboard processes that result in wastewater 

generation, as well as information regarding the types and amounts of pollutants that may be 

found in selected vessel discharges such as graywater and bilgewater. One source directly 

applicable to this study, however, is the UNDS document, Final Sampling Episode Report for 

Small Boat Engine Wet Exhaust Discharge from Compression Ignition Engines (USEPA, 

2008b), which provides pollutant data and other relevant information (e.g., vessel power levels) 

for wet exhaust discharges from two compression ignition engines. EPA used this report as a 

primary source of information and data for this vessel discharge. 

39 
Chapter 2 – Study Design 

2.1.2 Industry Participation

EPA was contacted by or contacted, met with, or otherwise collaborated with trade 

associations and individual companies. In the course of these meetings, EPA gathered the 

following types of information regarding vessel discharges: 

 Vessel classes within and outside the scope of this study. 

 Typical vessel lengths by vessel class. 

 Vessel operating seasons and locations. 

 Shipboard systems and operations that contribute to vessel discharges. 

 Vessel discharges and locations by vessel class. 

 Volume, frequency, and nature of discharges. 

 Vessel tours to inspect and observe vessel systems and operations that contribute to 

vessel discharges. 

Note that none of the trade associations or individual companies contacted were able to 

provide pollutant data for vessel discharges. 

The trade associations that contacted EPA or that EPA contacted included: 

 American Waterways Operators (represents over 250 members that operate carriers, 

tug boats, towboats, and barges). 

 Passenger Vessel Association (represents approximately 600 members that operate 

vessels such as ferries, dinner cruises, whale watching expeditions, site seeing tours, 

and water taxis). 

 National Association of Charterboat Operators (represents over 3,300 charterboat 

owner and operators who provide fishing, sailing, diving, eco-tours, and other 

excursion vessels that carry passengers for hire, as well as recreational for-hire 

vessels). 

 Conference of Professional Operators for Response Towing (C-PORT) (represents 

over 170 members of the commercial marine assistance industry, providing services 

such as jump starts, fuel delivery, and towing to boaters). 

 Pacific Seafood Processors Association (represents 10 seafood processing companies 

in Alaska, Washington, and Oregon). 

 At-Sea Processors Association (represents five companies that own and operate 19 

U.S.-flag catcher/processor vessels in the Alaskan pollock and West Coast Pacific 

whiting fisheries). 

 Alaskan Longline Fishermen’s Association (represents about 60 members of longline 

fishing vessel companies and salmon fishing vessels that operate in southeast Alaska). 

 United Fishermen of Alaska (represents about 37 commercial fishing organizations 

and associations concentrated in Alaska representing thousands of fishing companies 

operating as harvesters throughout Alaska waters and the adjoining Exclusive 

Economic Zone). 

 Southeast Alaska Fishermen's Alliance (represents commercial fishermen and the 

commercial fishing industry in southeast Alaska). 

40 
Chapter 2 – Study Design 

 Northeast Seafood Coalition (represents commercial groundfish fishermen and shoreside businesses from mid-coast Maine to Long Island, New York). 

 Southern Shrimp Alliance (alliance of shrimp fishermen and processors in Alabama, 

Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, and Texas). 

 Petersburg Vessel Owners Association (represents fishermen in Petersburg, Alaska). 

 Alaska Trollers Association (represents southeastern Alaska trollers). 

 Cordova District Fisherman United (represents Cordova, Alaska, area fishermen). 

Individual companies that provided additional information (generally after being 

contacted by their respective trade groups) included: 

 Potomac Marine, Woodbridge, Virginia. 

 Vane Brothers Company, Mid-Atlantic. 

 Potomac Riverboat Company, Alexandria, Virginia. 

 Northeast Seafood Processors, Gloucester, Massachusetts. 

 Vulcan Materials Company, Havre de Grace, Maryland. 

 Sea Tow, Pensacola, Florida. 

 EPA Gulf Ecology Division Laboratory, Gulf Breeze, Florida. 

 Sea Tow, Slidell, Louisiana. 

 AEP River Operations, Convent, Louisiana. 

 Shrimp Charters, Pass Christian, Louisiana. 

 Baltimore Water Taxi, Baltimore, Maryland. 

 Sitka Sound Seafoods, Sitka, Alaska. 

 Seafood Producers Co-op, Sitka, Alaska. 

 Silver Bay Seafoods, Sitka, Alaska. 

 Argosy Cruises, Seattle, Washington. 

 Tidewater Marine, LLC, Gulf Coast. 

 E.N. Bisso & Son, Lower Mississippi River. 

 Foss Maritime Company, California, Washington, Oregon, the Columbia River, and 

the Snake River. 

 Taku Smokeries, Juneau, Alaska. 

 Upper River Services, St. Paul, Minnesota. 

 JB Marine Service, St. Louis, Missouri. 

 Osage Marine Services, St. Louis, Missouri. 

 AEP River Operations, New Orleans, Louisiana. 

 Smith Shipyard, Baltimore, Maryland. 

 Norfolk Tug Company, Norfolk, Virginia. 

 Dann Marine, Baltimore, Maryland. 

 Cape Fear Riverboats, Wilmington, North Carolina. 

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Chapter 2 – Study Design 

2.1.3 Vessel Sampling

EPA identified a critical need for pollutant data for vessel discharges following its review 

of existing data sources. To satisfy this requirement, EPA designed and implemented a vessel 

discharge sampling program, which is described in detail in Section 2.2 of this document. 

Through this sampling program, EPA collected wastewater pollutant characterization data for 

nine vessel discharges sampled from a total of 61 vessels (one to four discharges sampled per 

vessel). These samples were collected in 15 different towns/cities in nine separate states, 

representing several of the major regions of the United States. Another critical component of 

EPA’s sampling program was the collection of information regarding the shipboard processes, 

equipment, materials, and operations that contribute to the discharges, as well as the discharge 

rates, duration, frequency, and location. 

2.1.4 Literature Review

EPA was not able to sample and characterize all study vessel classes and discharges 

(discussed further in Section 2.3). To fill this data gap, EPA searched the literature (i.e., 

scientific and engineering journals or other academic publications) for relevant information. In 

general, these searches provided only general information regarding vessel classes and 

discharges and little or no specific information, such as discharge composition and volumes. 

EPA did, however, identify many relevant literature sources regarding vessel antifouling 

leachate. EPA used these literature sources as the primary sources of information and data for 

this vessel discharge. 

2.1.5 Other Governmental Data Sources

EPA’s primary data source for vessel information regarding population and other vessel 

characteristics is the U.S. Coast Guard’s Marine Information for Safety and Law Enforcement 

(MISLE) database. The MISLE provides data for nearly 1 million vessels that operate in U.S. 

waters and is used to support the investigation and inspection activities of the U.S. Coast Guard 

throughout the United States and its territories. Of the 1 million vessels identified in the 

database, approximately 139,814 vessels comprise the study vessel population (see Chapter 1 for 

additional discussion). Relevant vessel characteristics tracked in this database are vessel type, 

length, geographical area of operation, age, hull material type, propulsion method and type, and 

horsepower ahead. 

EPA used a screening-level analysis of a hypothetical estuarine harbor to evaluate the 

potential environmental impacts from multiple vessels discharging to large U.S. water bodies, 

specifically estuaries and brackish harbors (see Section 4.2). EPA used the characteristics of 

harbor salinity, volume, and freshwater inflow from a variety of U.S. estuaries that receive vessel 

discharges to develop the characteristics for the hypothetical estuary. EPA compiled these 

characteristics from the following online sources: 

42 
Chapter 2 – Study Design 

 National Oceanic and Atmospheric Administration BookletChartTM List 

 National Oceanographic Data Center World Ocean Database 2005 (WOD05) 

 Southeast Environmental Research Center, Biscayne Bay Water Quality Monitoring 

Network, Miami, Florida. 

 Cronick, T., and A. McGuire. Temperature and Salinity of the Yaquina Bay Estuary 

and the Potential Range of Carcinus maenas, Corvallis, Oregon. 

 Massachusetts Department of Environmental Protection, Total Maximum Daily 

Loads of Bacteria for Little Harbor, Worchester, Massachusetts. 

 U.S. Geological Survey National Hydrography Dataset Plus. 

 U.S. Geological Survey National Water Information System Surface Water Annual 

Statistics. 

2.2 EPA VESSEL DISCHARGE SAMPLING PROGRAM

EPA conducted a sampling program of discharges from commercial fishing vessels and 

other nonrecreational vessels less than 79 feet in length. EPA’s sampling program was designed 

to provide information to achieve the first two objectives of the study mandated by P.L. 110-299: 

 A characterization of the nature, type, and composition of discharges for 

representative single vessels, and for each class of vessel. 

 A determination of the volumes of those discharges, including the average volumes 

for representative single vessels, and for each class of vessel. 

Accordingly, EPA’s sampling program included the sampling of large numbers and 

varieties of vessel classes, vessels, and discharges, and the analysis of target analytes as 

discussed in the following subsections. In addition, EPA supplemented sample collection and 

analysis with the collection of information regarding the shipboard processes, equipment, 

materials, and operations that contribute to the discharges, as well as the discharge rates, 

duration, frequency, and location. 

Though the Agency was still in the final stages of drafting the 2008 VGP, EPA began 

designing and planning the sampling program soon after enactment of P.L. 110-299. These 

activities included developing the size and scope of the program considering overall program 

schedule and resources; identifying priority locations, vessel classes, discharges, and analyte 

classes for sampling; developing a detailed Generic Sampling Analysis Plan and Quality 

Assurance Project Plan; procuring EPA regional laboratory and contract laboratory and sampling 

support; and soliciting industry input and volunteers for participation in the program. Sample 

collection was conducted from March through July 2009. The remainder of this section provides 

a further description of the sampling program, including the vessels sampled and their locations, 

sampled discharges, target analytes, sampling methods, and quality assurance/quality control. 

43 
Chapter 2 – Study Design 

2.2.1 Vessels Sampled and Locations

EPA sampled discharges from a total of 61 vessels in nine vessel classes (see Table 2.1). 

To select vessel classes for evaluation, EPA first developed a list of commercial vessel classes 

based on published information and the EPA team’s existing understanding of vessels. Next, 

EPA narrowed the sampling scope to focus largely on those vessel classes believed to consist 

primarily of vessels less than 79 feet in length. Some examples of vessel classes on which EPA 

did not focus, due to their size, include cable laying ships, cruise ships, large ferries, oil and 

petroleum tankers, and freight ships/barges (most vessels in these classes are typically greater 

than 80 feet in length). Next, EPA eliminated vessel classes outside the scope of study vessels, 

including stationary seafood processing vessels and vessels that can be secured to the ocean floor 

for mineral or oil exploration, because the industrial discharges from these vessels were outside 

the scope of the previous 40 CFR Part 122.3(a) exclusion (USEPA, 2008d). After eliminating 

these vessels, the following common vessel classes were prioritized for evaluation: 

 Commercial fishing vessels and tenders 

 Tugs/towing vessels 

 Water taxis/small ferries 

 Tour boats 

Purse Seiner in Alaska (left) and a Shrimp Trawler in Louisiana (right). 

44 
Chapter 2 – Study Design 

A Tugboat in Maryland (left) and a Tow/Salvage Vessel in Virginia (right). 

A Water Taxi in Virginia (left) and a Tour Boat in Virginia (right). 

45 
Table 2.1. Number of Vessels Sampled by Vessel Class and Discharge 

Vessel Class Number of Number of Vessels Sampled by Discharge 

Vessels 

Sampled 

Bilge 

Water 

Stern Tube 

Packing 

Gland 

Deck 

Washdown 

Fish Hold Cleaning of 

Fish Hold 

Graywater Propulsion 

Engine Efflue

Fi shin

g:

 Gillnetter 5 1 3 1  Lobster 1 1 1  Longliner 3 1 3 1  Purse Seiner 5 5 1 1  Shrimp Trawler 6 1 6 2 1  Tender 3 3 2  Trawler 4 2 3 4  Troller 6 2 6 1 Tugboat 9 9 9 5 Water Taxi 4 2 1 1 4 Tour Boat 3 1 2 3 Tow/Salvage 6 3 6 5 Research 2 2 Fire Boat 1 1 1 Supply Boat 1 1 Recreational 2 1 1 2 

Total 61 8 9 32 26 9 8 19 

(1) Sampled the lobster hold tank on a trawler.

46 
Chapter 2 – Study Design 

Additionally, EPA sampled recreational vessels used for nonrecreational purposes as part 

of this study. This sampling was done for two purposes: 1) to provide a semiquantitative 

comparison of the discharges from these vessels and the other study vessels, and 2) to collect 

additional information for EPA’s related work on the Clean Boating Act (P.L. 110-288). During 

the execution of the sampling program, EPA also conducted opportunistic sampling of additional 

non-priority vessel classes (e.g., fire boats, recreational boats, a supply boat) when EPA had 

access to these vessels and the resources to sample them. See Section 1.3 of this document for a 

short description of different vessel classes or types. 

As discussed in Section 2.1.2, EPA was contacted by or otherwise developed contacts 

with trade associations and individual companies. Many of these entities relayed the purpose of 

the study to their constituents or peers, some of whom contacted EPA. Consequently, EPA 

obtained a pool of individual companies who were willing to volunteer their vessels for the 

sampling program. EPA then selected specific companies and vessels within the volunteer pool 

for sampling to obtain a variety of vessel classes, vessel platforms, companies, and geographic 

distribution. In general, EPA selected the entire volunteer pool within the following geographic 

areas to maximize the number and variety of sampled vessels based on available resources: New 

England (Gloucester/New Bedford, Massachusetts); Mid-Atlantic (Woodbridge, Virginia; 

Alexandria Virginia; Baltimore, Maryland; Havre de Grace, Maryland; and Philadelphia, 

Pennsylvania); Gulf Coast (Gulf Breeze, Florida; Pensacola, Florida; Bayou la Batre, Alabama; 

Pass Christian, Mississippi; Slidell, Louisiana; La Fitte, Louisiana; and Convent, Louisiana); and 

Sitka, Alaska. 

EPA’s vessel selection approach for commercial fishing vessels differed from that of 

other vessel classes due to the nature of this industry. During the fishing season, fishing trips 

typically last for multiple days with no preset schedule. The captain of each vessel determines 

the end of each fishing trip, returns to the seafood processor or tender to offload the catch, and 

then typically immediately returns to the fishing grounds. Therefore, EPA identified seafood 

processors, rather than specific fishing companies and vessels, as the means to obtain a pool of 

active fishing vessels for sampling. Sampling was conducted at the docks of the seafood 

processors during the offloading process, and EPA sampled all vessels that arrived while the 

EPA sampling crew was at the docks (with the permission of the captains). In this way, sampling 

of individual commercial fishing vessels was random. However, EPA did contact the seafood 

processing facilities prior to sampling to provide sampling details (e.g., nature of the study, 

discharges of interest, sampling dates). It was the facilities’ discretion whether or not to share 

this information with the vessel fleets that use their offloading facilities. 

Due to the assistance of trade groups and others, vessel owner/operators were generally 

very cooperative with EPA sampling teams. For example, the EPA vessel team found that most 

of the fishermen with whom they spoke in Sitka, Alaska, were aware of the study and that EPA 

would be sampling in the area during the summer. Other vessel owner/operators took EPA 

47 
Chapter 2 – Study Design 

underway to sample engine effluent, waited to wash their dishes or take showers until EPA was 

able to collect the graywater discharge, and assisted EPA scientists in answering questions about 

their vessel operations. 

 During the public comment period for this report, EPA received comments noting that the 

types of vessels sampled for this study were not necessarily representative of the industry as a 

whole, specifically for commercial fishing vessels. Based on public comments, EPA evaluated 

the representativeness of the sampled commercial fishing vessels in terms of size, class, and 

geographic distribution. The commercial fishing industry is highly diverse (spanning a wide 

array of ocean and nearshore conditions, differing by both region and fishery). With respect to 

vessel size, EPA notes that the sampled commercial fishing vessel population does not represent 

discharges from vessels less than 26 feet in length, which comprise an estimated 10% of the 

overall commercial fishing vessel population. However, though EPA did not physically sample 

these vessels, we visually observed that these small vessels typically store their catch in coolers 

(which do not have a discharge) rather than in refrigerated seawater or ice holding tanks, which 

is a function of their relatively short fishing voyages. For larger fishing vessels, EPA believes the 

sampled vessel population is reasonably representative of the overall vessel population, albeit 

somewhat more heavily weighted toward the largest of commercial fishing vessels (i.e., 50 feet 

or more). 

 With respect to vessel class, EPA’s sampled commercial fishing vessel population 

includes vessels in all of the fishing vessel classes. Furthermore, the percentage of sampled 

vessels by class is similar to or greater than the percentage of the overall vessel population by 

class for all vessel classes except for Pot/Trap vessels. Pot/Trap vessels include many of the 

smallest commercial vessels that are not represented by EPA’s sampled vessel population. EPA 

also notes that it sampled a much higher percentage of Seiners than the overall vessel population 

(15% of vessels sampled versus only 2% of the overall vessel population). Sampling in Sitka, 

AK occurred at the start of the salmon fishing season, resulting in a preponderance of Seiners at 

the docks of seafood processers. 

 Finally, with respect to geographic distribution, EPA sampled commercial fishing vessels 

in the following regions: Alaska (21 vessels); Gulf Coast (6 vessels); and New England (6 

vessels). According to the National Marine Fisheries Service, in 2008 these three areas combined 

represented approximately 77% of U.S. domestic commercial landings in 2008. Among the 

remaining geographic regions that EPA was unable to sample, the Pacific Coast (excluding 

Alaska) has the greatest landings in 2008 at 13% of U.S. domestic commercial landings; 

commercials fishing vessels in this region are expected to be similar to those in Alaska. Finally, 

many of other remaining geographic regions that EPA was unable to sample, such as the 

Chesapeake Bay, Middle Atlantic, and the Great Lakes, are likely dominated by small fishing 

vessels that most likely have low volumes of or no fish hold effluent discharges. 

Hence, with the exception of the smallest commercial fishing vessels, EPA believes that 

the sampled vessel population is a representative cross-section of vessels and is adequate to 

evaluate the vessel population for the purpose of this study. 

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Chapter 2 – Study Design 

2.2.2 Sampled Discharges 

EPA sampled a total of nine discharge types during the sampling program (see Table 

2.1). To identify priority discharges for sampling, EPA first developed a list of vessel discharges 

based on information collected from discussions with industry representatives (see Section 

2.1.2), as well as EPA’s understanding of vessel discharges. Next, EPA prioritized the list to 

focus on the following discharges that are commonly generated by the vessel classes of interest 

and that are amenable to sampling (see Chapter 1 for descriptions and locations of these 

discharges): 

 Bilgewater 

 Stern tube packing gland effluent 

 Deck runoff and/or washdown 

 Fish hold effluent (including both refrigerated seawater effluent and ice slurry) 

 Effluent from the cleaning of fish holds 

 Graywater 

 Propulsion engine effluent 

 Generator engine effluent 

 Firemain discharges 

Vessels routinely use ambient waters to conduct normal operational and cleaning 

activities that lead to the generation of above discharges. EPA collected samples of ambient 

water where the vessels were operating. EPA also collected potable water used onboard the 

vessels (service water) to characterize any background concentrations of pollutants that might be 

detected in discharges from vessel operations that use service water. 

Various Discharges Through Hull Discharge Ports Various Discharges Through Hull Discharge Ports. 

49 
Chapter 2 – Study Design 

EPA did not select non-oily machinery wastewater as a priority discharge for sampling 

because it was not expected to be discharged separately from bilgewater. The vessels that EPA 

sampled during this program use the bilge system to manage non-oily machinery wastewater (if 

there is any), such as fresh- and saltwater pump drains, chilled water condensate drains, and 

potable water tank overflows, rather than installing dedicated drip pans, funnels, and deck drains 

to provide for segregated discharge. Note, however, that EPA has not performed a 

comprehensive investigation of whether or not certain non-oily machinery wastewaters may have 

segregated discharges on other study vessels. 

EPA did not select the discharges listed below as priority discharges for sampling 

because they were not reasonable or practical to sample within the overall program schedule and 

available resources. 

 Anti-fouling hull coatings. 

 Cathodic protection. 

 Controllable pitch propeller and thruster hydraulic fluid and other oil-to-sea 

interfaces. 

 Underwater ship husbandry. 

EPA did not select the discharges listed below as priority discharges for sampling 

because they were not expected to be commonly generated on commercial fishing vessels or 

nonrecreational vessels less than 79 feet in length. 

 Aqueous film-forming foam 

 Boiler/economizer blowdown 

 Distillation and reverse osmosis brine 

 Elevator pit effluent 

 Exhaust gas scrubber wash water 

 Freshwater layup 

 Gas turbine wash water 

 Motor gasoline and compensating discharge 

 Sonar dome discharge 

 Welldeck discharges 

 Graywater mixed with sewage 

None of these discharges were sampled during the sampling program because none of the 61 

vessels that EPA selected for sampling generated these discharges. Note, however, that EPA has 

not performed a comprehensive investigation of whether or not these discharges are applicable to 

other study vessels. 

50 
Chapter 2 – Study Design 

51 

2.2.3 Target Analytes

EPA’s vessel discharge sampling and analysis program included 301 target analytes in 

the following eight analyte groups:1

 

 Microbiologicals (pathogen indicators) 

 Volatile and semivolatile organic compounds 

 Total and dissolved metals 

 Oil and grease 

 Sulfide 

 Long and short chain nonylphenol and octylphenol ethoxylates (i.e., alkylphenol 

ethoxylates) and total nonylphenol (NP) 

 Nutrients 

 Other physical/chemical parameters 

Appendix D lists the target analytes included in each group, along with the analytical 

methods. EPA selected this comprehensive list of analytes to perform a screening-level analysis 

of the presence or absence of almost all priority pollutants (listed at 40 CFR Part 423, Appendix 

A), conventional pollutants defined at Section 304(a)(4) of the Clean Water Act, and toxic 

pollutants from EPA’s 2006 National Recommended Water Quality Criteria for freshwater and 

saltwater aquatic life and human health, as well as many other nonconventional pollutants. 

Nearly half of these analytes (147) were never detected in any vessel discharge sample (see 

Chapter 3). 

EPA did not analyze all vessel discharges for all selected analyte groups (see Table 2.2). 

Analyte groups were selected for analysis based on their possible presence in discharges, as 

determined from existing data sources and EPA’s understanding of what constituents are 

possibly present in the different vessel discharges. For example, long-chain nonylphenol and 

octylphenol ethoxylates were only analyzed for in those discharges with the potential to contain 

detergents (i.e., bilgewater, packing gland, deck washdown, fish hold cleaning effluent, and 

graywater). Furthermore, short-chain nonylphenol and octylphenol ethoxylates and NP were only 

analyzed for in those discharges for which the long-chain structural isomers of these two subsets 

of alkylphenol ethoxylates were analyzed, and that also had a holding time onboard the vessel 

that would allow for the possible degradation of the long-chain isomers to the short-chain 

isomers and NP (e.g., bilgewater held in the bilge, graywater stored in a holding tank). 

 

1

 Due to overall program resource constraints and other factors, not all analyte groups of possible concern were 

selected for this study (see Section 2.3.3). 
Table 2.2. Analyte Groups by Discharge 

Vessel Class and Priority Discharge 

Microbiologicals 

Volatile and Semivolatile Organic 

Compounds 

Metals (Total and 

Dissolved) 

Oil and Grease 

Sulfide 

Short-Chain 

Alkylphenol 

Ethoxylates and NP 

Long-Chain 

Alkylphenol 

Ethoxylates 

Nutrients 

BOD

5, COD, TOC 

Bilgewater √ (c) √ √ √ √ √ √ √ √ Stern tube packing gland effluent √ √ √ √ √ √ √ √ Deck runoff and/or washdown √ (d) √ √ √ √ √ Fish hold effluent (including both refrigerated seawater effluent and ice slurry) 

√ √ √ √ √ √ 

Effluent from the cleaning of fish holds √ √ √ √ √ √ √ Graywater √ √ √ √ √ (e) √ √ √ Propulsion engine effluent √ √ √ √ Generator engine effluent √ √ √ √ Firemain systems √ √ (a) Biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and total organic carbon (TOC). 

(b) Other physical/chemical parameters include: conductivity; dissolved oxygen; pH; salinity; temperature; total residual chlorine; turbodor, color, and floating and settleable material. (c) Microbiologicals analyzed for only those vessels with potential for a source of these pollutants to enter the bilge (e.g., graywater pi

(d) Microbiologicals analyzed for only commercial fishing vessels. (e) Short-chain alkylphenol ethoxylates (i.e., nonylphenol and octylphenol ethoxylates) and NP analyzed only for graywater that has btank prior to discharge.

52 
Chapter 2 – Study Design 

2.2.4 Sampling Methods 

EPA used a variety of sample collection methods depending on the nature of the 

discharge. This section describes the most commonly used sampling methods. 

Discharge from a discharge port well above the water line. 

Samples of these types of discharges were typically collected directly into a 5-gallon 

utility bucket lined with a new pail liner. For some samples, the bucket could be lowered by 

hand, while for other samples, the bucket was lowered by rope. The sample in the pail liner was 

then poured into the individual sample bottles. Whenever possible, samples for analysis of oil 

and grease were collected directly into the sample bottles (either held by hand or attached to a 

pole) to avoid the possible loss of oils to the sides of the sample transfer jar and pail liner. 

However, when oil and grease sample bottles were filled directly by attaching to a pole, it was 

typically necessary to “top off” the sample bottles with sample from the pail liner to ensure 

adequate sample volume for analysis. 

Sample Collection Well Above the Water Line. 

Discharge from a discharge port at or below the water line. 

Typically, samples of these types of discharges were impossible or too unsafe to collect. 

In a few cases, however, EPA was able to collect samples upstream of the discharge port via a 

sampling port. For example, on one vessel, engine effluent could be accessed from a petcock 

valve on the muffler. Samples of these types of discharges were preferentially collected directly 

into sample bottles. In some cases, the clearance between the sampling port and the vessel hull 

53 
Chapter 2 – Study Design 

was insufficient to accommodate the sample bottles and instead, required sample collection 

directly into a new pail liner; the sample in the pail liner was then poured into the individual 

sample bottles. 

Close Up of Petcock Valve Close-up of Petcock Valve. 

Deck washdown and runoff. 

Deck washdown and runoff wastewater is discharged through scuppers located along the 

perimeter of the deck. To collect samples of this discharge, EPA generally directed the discharge 

to one or more (up to four) select scuppers using a variety of methods. On some vessels, deck 

washdown water naturally flowed by gravity to one or more scuppers at the lowest end of the 

deck. On other vessels, EPA used either the spray from the hose used to wash the deck or the 

broom used to wash the deck to direct the deck washwater to one or more selected scuppers. 

Finally, on some vessels, EPA arranged the deck washing hose on the vessel deck such that it 

directed and pooled deck washdown water to one or more selected scuppers. To collect the 

discharge from a selected scupper, EPA held a new pail liner against the hull of the vessel to 

capture the deck washdown water as it drained through the scupper. If deck washdown water was 

discharged through multiple scuppers, EPA filled the pail liners proportionally from each 

scupper (e.g., half from each of two scuppers, one-third from each of three scuppers). The 

sample in the pail liner was then poured into the individual sample bottles. 

54 
Chapter 2 – Study Design 

Deck Cleaning and Collecting Deck 

Washdown Sample. 

Collecting Deck Washdown 

Sample with Close-up of Scupper 

(Indicated with Red Arrow).

For select fishing vessels, EPA attempted to collect samples of runoff during actual 

fishing operations. EPA arranged to travel with an overnight shrimping vessel on the Gulf Coast; 

however, due to a temporary seasonal shrimp fishery closing, EPA obtained a research permit to 

collect runoff from “demonstration” operations. Because these were demonstration operations 

and the shrimp fishermen would be unable to keep the catch, the vessel operator used a smaller 

net for shorter durations and did not handle the catch as he normally would. As a result, these 

samples only partially resemble normal operations. While in Alaska, the U.S. Coast Guard 

assisted EPA in attempting to sample deck washdown from fishing vessels immediately after 

they pulled in their catch. EPA and the Coast Guard attempted to sample three to five vessels 

during this operation. Due to weather conditions, however, they were only able to sample one 

vessel successfully. 

Fish hold tanks. 

Three types of fish hold tanks were sampled during the program: tanks containing 

refrigerated seawater, tanks containing ice slurry, and tanks containing chipped ice. Refrigerated 

seawater tanks were common to tenders, purse seiners, and trawlers, while slurry and chipped ice 

tanks were common to trollers, long-liners, gillnetters, and some trawlers. For vessels with 

refrigerated seawater tanks, fish are typically extracted using a vacuum system that removes both 

the fish and refrigerated seawater simultaneously. Both fish and refrigerated seawater are 

transferred to the seafood processing plant. The refrigerated seawater is generally recycled back 

to the fish hold tank to provide the liquid needed to operate the vacuum system. Any excess 

refrigerated seawater that is not required to assist in fish extraction is pumped overboard pier 

side. EPA collected samples of the refrigerated seawater directly into a 5-gallon utility bucket 

lined with a new pail liner as the water was pumped overboard. The sample in the pail liner was 

then poured into the individual sample bottles. Because removal of fish and refrigerated seawater 

55 
Chapter 2 – Study Design 

can take several hours depending on the vessel size, EPA collected the sample approximately 

mid-way through the fish removal process. For vessels such as trollers and long-liners, which use 

chipped or slurry ice, EPA collected a sample of the ice or slurry once the fish had been removed 

from the fish hold tank. Ice/slurry was collected into a new pail liner and allowed to melt. Once 

melted, the sample was poured from the pail liner into the individual sample bottles. 

Collecting Fish Hold Sample with a Lined Bucket Collect Collect Collecting Fish Hold Sample with a Lined Bucket.

 

Fish hold cleaning. 

After the fish hold has been evacuated, the vessel crew cleans the fish hold as described 

in Section 1.3. For vessels with refrigerated seawater tanks or chipped ice tanks, the fish hold 

cleaning wastewater is pumped overboard. EPA collected samples of the fish hold cleaning 

wastewater directly into a 5-gallon utility bucket lined with a new pail liner as the cleaning water 

was pumped overboard. 

Firemain. 

EPA used valving on the firemain system to throttle the flow rate to allow firemain 

samples to be collected from the fire hose directly into sample containers. None of the vessels 

visited by EPA for this study tests its firemain system more frequently than once every two 

weeks, and none operates its system for secondary purposes such as deck washing. Of the six 

firemain systems sampled, five were wet systems (the firemain piping is normally filled with 

water) and one was a dry system (the firemain piping is normally filled with air). The resulting 

56 
Chapter 2 – Study Design 

sampling data are applicable to firemain systems that are operated infrequently with intake 

provided by surrounding water and without additions to the discharge (e.g., no addition of foamforming agents). 

Composite samples of multiple wastewaters. 

To better characterize some discharges, EPA decided to combine multiple samples of 

wastewaters into a single sample for analysis. The most common example is a vessel that 

operates its engines at multiple power levels—idle at the pier, half-speed when motoring through 

the no wake zone, and three-quarter speed when performing harbor tours. Another example is a 

vessel that generates two types of graywater—wastewater from a galley sink and wastewater 

from a shower. In these cases, EPA filled a new pail liner proportionally based on the number of 

wastewater sources (e.g., one-third from each of three power levels, half from each of sink and 

shower water) using one or more of the sample collection methods described above. The sample 

in the pail liner was then poured into the individual sample bottles. Whenever possible, EPA 

collected and analyzed separate samples for each discharge for oil and grease and for volatile 

organics, rather than using the composite sample; this minimized the possible loss of these target 

analytes from volatilization during sample transfer among multiple sampling equipment or due to 

adherence of oils to the sides of multiple sampling equipment. 

 

57 

Collecting Engine Effluent with a Transfer Jar. Compositing the Sample in a 

Lined Bucket.
Chapter 2 – Study Design 

2.2.5 QA/QC 

Quality assurance/quality control (QA/QC) procedures applicable to EPA’s vessel 

sampling program are outlined in the Quality Assurance Project Plan for Discharges from 

Commercial Fishing Vessels and Other Non-Recreational Vessels Less Than 79 Feet (QAPP), 

which is included in the docket of the Federal Register notice announcing this study. This section 

describes the QC practices used to assess the precision and accuracy of the analytical data. 

2.2.5.1 Analytical Quality Control 

Analytical chemistry support for this program was provided by EPA’s own laboratories 

in Regions 2, 3, and 5, as well as several subcontract laboratories. The EPA Regions were 

responsible for the quality of the work generated by their laboratories and for verifying that 

laboratory performance was acceptable by conducting QC checks of the analytical data as 

specified by the QAPP. Subcontract laboratories functioned within the quality system of EPA’s 

sampling contractor, who verified the acceptability of subcontract laboratory performance by 

conducting QC checks of the analytical data as specified by the QAPP. Based on the data quality 

review and evaluation of the analytical data under this sampling program, all analytical data were 

deemed within or sufficiently close to the target analytical QC limits established for the study to 

assure the data could be used for the specified intentions. QC failures were generally attributed to 

matrix interference; these results are not uncommon for complex wastewater samples. 

Furthermore, the sample collection, handling, preparation, and analysis process utilized in this 

sampling program was deemed acceptable for the matrices and conditions sampled. 

2.2.5.2 Field Quality Control 

Field QA/QC measures and results for the bottle blanks, equipment blanks, trip blanks, 

field blanks, and field duplicates are discussed in this subsection. 

Bottle blank. 

A representative bottle and cap from the first lot of bottles purchased for collection of 

samples for analysis of pathogen indicators were analyzed for wide-spectrum contamination 

prior to their use in the sampling program. Bottles were filled with sterile deionized water, and 

100–milliliter (mL) aliquots were filtered by membrane filtration. The filters were placed on 

water agar, nutrient agar, modified mTEC agar (for E. coli cultures), and mEL agar (for 

enterococci cultures). No pathogen indicators or other organisms (water or nutrient agar) were 

detected in the bottle blank, indicating that the bottles were sterile.

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Chapter 2 – Study Design 

Equipment blanks. 

Two equipment blanks were prepared and analyzed for volatile and semivolatile organic 

compounds (SVOC), total and dissolved metals, nutrients, soaps and detergents, and other 

physical/chemical parameters to assess the potential introduction of contaminants by sample 

collection equipment. The sample collection equipment used to collect the equipment blanks was 

the same as that used at the sampling points: 1) a new, factory-cleaned, Teflon® PFA pail liner 

from the first lot of bags purchased from the vendor, and 2) a 3-foot segment of silicone tubing 

connected to a 25-foot segment of Teflon tubing used in the peristaltic pump (only used on three 

samples throughout the entire project). The pail liner equipment blank was prepared by rinsing 

the bag with high performance liquid chromatography (HPLC) water and then pouring it into 

sample bottles. The pump tubing equipment blank was prepared by pumping HPLC water 

through this equipment and collecting directly into sample bottles. Of the 459 equipment blank 

sample results, 29 (6.3 percent) were above the method reporting limit (RL). Of the cases where 

the equipment blank exceeded the RL, 15 were for SVOC analytes and seven were for VOC 

analytes. In all 22 of these cases, however, the analytes were tentatively identified compounds 

(TICs), which are appropriately labeled in the analytical database as such. The remaining cases 

where the equipment blank exceeded the RL were as follows: biochemical oxygen demand 

(BOD) (two instances), chemical oxygen demand (COD) (two instances), total Kjeldahl nitrogen 

(TKN) (one instance), nitrate/nitrite nitrogen (one instance), and zinc (one instance). In each 

instance, the vast majority (greater than 90 percent) of the associated discharge sample amounts 

were significantly higher than the equipment blank levels. 

Trip blanks. 

Trip blanks were prepared and analyzed for volatile organics to evaluate possible 

contamination during shipment and handling of samples. These samples consisted of HPLC 

water poured into the sample bottles and transported unopened to the field and finally to the 

laboratory. One trip blank was prepared for each location-specific sampling event (e.g., Gulf 

Coast, New England). Evaluation of the trip blanks indicated that of the 612 VOC results for 

these samples, only two analytes were detected (tetramethylsilanol and tetrahydrofuran), and 

these were at levels below the RL. Neither of these analytes was detected in any vessel discharge 

samples, indicating that there was no sample contamination during transport, field handling, and 

storage. 

Field blanks.

Field blanks were prepared and analyzed for all target analytes to monitor for the 

contamination of samples during sample collection and handling. These samples were prepared 

aboard selected vessels at the location of greatest potential for contamination (e.g., the vessel 

bilge space). The samples were prepared by pouring HPLC water into the sample bottles. One 

field blank was prepared for each location-specific sampling event (e.g., Gulf Coast, New 

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Chapter 2 – Study Design 

England). Only six target analytes (conductivity, dissolved organic carbon, nitrate/nitrite, TKN, 

turbidity, and total zinc) were detected in any of the 670 field blank results (0.3 percent) at levels 

above the RL. In each instance, the associated discharge sample amounts were significantly 

higher than the field blank levels. 

Field duplicates. 

Field duplicate samples were collected and analyzed for all target analytes to assess the 

precision of the entire sample collection, handling, preparation, and analysis process. Field 

duplicate samples were collected simultaneously from the same location as the original samples 

(i.e., poured from the pail liner as a split sample or sampled sequentially when collecting samples 

directly into sample bottles from discharge ports). The relative percent difference (RPD) between 

the two duplicate sample results was calculated and compared to the data quality objective. The 

occurrence of field duplicate samples (number of samples exceeding out of total number of 

duplicate samples) where one or more analytes within an analyte type (VOCs, SVOCs, dissolved 

metals) exceeded the target RPD was 89 of 356 pairs of field duplicate samples, or 25 percent. 

The higher RPDs were calculated in samples where the concentrations of the analytes were 

detected at levels at or near the detection level for the respective methods, mainly for VOCs, 

Silica Gel Treated N-Hexane (SGT-HEM), and residual chlorine. For these methods, the 

analytical variability increases as analyte concentrations approach their detection limits. These 

results are not uncommon in complex wastewater samples. 

2.2.5.3 Database Development 

An Access database was created in which to collect and organize all analytical results. 

This database contained data and associated qualifier information. Although a number of EPA 

and contractor staff were involved in reviewing the results, only one person had the authority to 

make any changes to the database during its development. This one-person control system 

eliminated the possibility of someone accidentally creating more than one current version of the 

database and minimized the risk of errors. Each time the database was updated, the current date 

and time stamp were used to name the new version, which was uploaded to a secure FTP server. 

After each sampling event, the chains of custody (COC) and field data sheets were used 

to manually enter information into the “COC Information” table. This table contained identifiers 

given to samples in the field (FieldIDs) associated with vessel name, location, and discharge 

information, as well as the sample date and time. A second person performed a 100-percent 

check of the data entered to ensure there were no transcription errors or mistakes made during 

data entry. 

Four analytical chemistry and subcontract laboratories —EPA Region 2 (Edison, New 

Jersey), EPA Region 3 (EPA Environmental Science Center, Fort Meade, Maryland), TriMatrix 

(Grand Rapids, Michigan), and Admiralty (Juneau, Alaska)—provided EPA’s contractor with 

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Chapter 2 – Study Design 

electronic data deliverables (EDDs) in either Excel or delimited text format. EDDs were first 

imported into the database as new tables that remained unaltered while the fields of interest, 

contained therein, were appended to a table called “Vessel Results.” The remaining fields were 

populated using queries. Ten percent of the data in the Vessel Results table from three of the four 

laboratories were compared to the original hard copy reports, if provided. This ensured 

consistency between the EDD and hard copy report, as well as validated the importing 

procedure. As a further quality assurance measure, a 100-percent check was done comparing 

these PDF reports to database entries derived from the fourth lab’s EDD reports. 

Data that were not received in EDD format (i.e., hard copies, PDFs, and field data sheets) 

were manually entered directly into the Vessel Results table. These data were provided by six 

additional analytical chemistry and subcontract laboratories: EPA Region 5 (Chicago, Illinois), 

Biomarine (Gloucester, Massachusetts), EnviroChem (Mobile, Alabama), QC Laboratories 

(Southampton, Pennsylvania), Northeast Environmental Laboratory (Danvers, Massachusetts), 

and Sitka Water Treatment Plant (Sitka, Alaska). As with the COC information, a second person 

did a 100-percent check of the accuracy of data entry. 

In addition to checking for reporting accuracy, a check of laboratory QC procedures was 

performed. EPA examined laboratory QC parameters, including method type, hold times, 

laboratory blanks and duplicates, laboratory control samples, and surrogate recovery, where 

applicable, for all subcontract laboratories. 

2.3 DATA CONSIDERATIONS AND STUDY LIMITATIONS

2.3.1 Voluntary Nature of the Sampling Program

All vessel sampling performed for this study was conducted on a voluntary basis (i.e., 

vessel owners/operators voluntarily allowed EPA to sample their vessels). As such, the selection 

process was not completely random from within the universe of study vessels, nor were the 

vessels sampled unannounced, with the possible exception of fishing vessels (see Section 2.2.1). 

These issues raise potential concerns regarding the representativeness of the sampling and the 

statistical uncertainty of the resulting data analyses. To minimize these concerns, EPA provided 

study volunteers with guidance for participation in the sampling program. This guidance stressed 

EPA’s desire to sample normal discharge cycles/events and requested that volunteers not alter 

vessel operations from normal (typical) operation. The guidance specifically instructed that 

volunteers should not perform any special cleaning in preparation for sampling, add or eliminate 

or alter any typical discharges, or increase or decrease the volume or other characteristics of 

discharges, etc. Also, as EPA preferred to collect samples pierside rather than underway, EPA 

instructed volunteers to inform the Agency if conducting sampling pierside compromised, in any 

way, the characteristics of discharges (sources, volumes, composition). 

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Chapter 2 – Study Design 

As a further consideration, EPA assumed that most of the volunteers were generally 

‘good actors’ who would have the best maintained vessels and be in compliance with all existing 

applicable regulations, which could also affect the representativeness of the data collected for the 

vessel class as a whole. 

2.3.2 Vessels/Discharges Not Sampled 

While this study included the sampling of a large number of discharges from a large 

number of vessels, certain vessel classes and discharges were either not sampled at all or 

received only limited sampling due to overall program schedule and resource constraints or other 

factors (see Sections 2.2.1 and 2.2.2). EPA supplemented its sampling program with information 

and data collected from other data sources to the extent possible; however, the Agency 

acknowledges remaining gaps in achieving the study objectives for certain segments of the 

industry. In particular, EPA has little or no information or data regarding freight barges, freight 

ships, tank barges, and tank ships less than 79 feet in length (estimated to represent 7 percent of 

study vessels). In addition, EPA has little information or data regarding the applicability of 

several discharges listed in Section 2.2.2 to study vessels. 

EPA’s ability to fully characterize certain discharges was limited by some practical 

considerations. For example, on many vessels, discharges were too close to the waterline, or 

even under the waterline, precluding the ability to collect an uncontaminated sample. Installation 

of sample taps upstream of these discharge ports was either impossible (i.e., would compromise 

system integrity) or impractical within time constraints for the sampling events. On other vessels, 

collection of vessel discharges under normal operations was either impossible or unsafe. These 

conditions included: 

 Vessel configurations blocking access to discharge ports 

 Discharge volumes insufficient for sampling 

 Discharges not generated during the sampling event 

 Systems such as generators not operational during the sampling event 

 Systems operated only during emergency 

 Discharges requiring underway sampling 

 Fishing vessel platforms inactive during the sampling schedule 

 Fishing seasons closed or outside the sampling schedule 

 Inability to sample all U.S. fisheries 

As an example, EPA was able to sample bilgewater on only eight of the 61 sampled 

vessels (13 percent). Bilgewater sampling was infeasible for approximately three quarters of the 

remaining vessels for three reasons. First, automatic bilge pumps operating while the vessel was 

underway resulted in an empty bilge when the vessel returned to pier. Manual activation of the 

bilge pump on these vessels did not result in any discharge or only a small volume of discharge. 

Second, as a matter of policy, many vessels restrict bilgewater discharges to only while 

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Chapter 2 – Study Design 

underway or when outside U.S. waters due to possible concerns of exceeding existing Clean 

Water Act § 311 requirements. Third, some bilgewater discharges were too close to the waterline 

for sampling. For the remaining one quarter of vessels, sampling was not performed because the 

vessels never discharge bilgewater. On these vessels, a contractor steam cleans the bilges once 

per month, and the resulting cleaning waste is removed from the vessels for shoreside disposal. 

2.3.3 Pollutants Not Sampled 

A few candidate analyte groups (pesticides, polychlorinated biphenyls, dioxins/furans, 

flame retardants, uranium, and asbestos) were not selected for analysis, as they are not 

anticipated to be present in the vessel discharges due to the lack of a readily apparent source for 

these pollutants. 

While EPA’s list of target analytes includes many persistent, bioaccumulative, and toxic 

chemicals (PBTs), many other PBTs were not analyzed for due to the lack of test methods or 

resources. In general, these unanalyzed compounds either have no known use or source onboard 

vessels or have no readily available means to enter the vessel discharges. Mercury was not 

selected for analysis because it requires specialized sampling techniques inapplicable to vessel 

sampling to minimize the potential for sample contamination (e.g., vessel sampling cannot be 

conducted away from sources of metals or sources of airborne contamination such as engines or 

generators). 

Test methods for pharmaceuticals and personal care products (PPCPs) have recently been 

developed; however, EPA did not select this analyte group for analysis due to a lack of 

resources. These compounds are most likely to be found in sewage, which is outside the scope of 

this study; however, they can also be expected to be found in graywater sources, such as sink and 

shower wastewater, albeit at very low concentrations. 

Although ballast water, and its assessment as a vector for aquatic invasive species, was 

specifically excluded from this study by the statutory language in P.L. 110-299 (see Appendix 

C), EPA recognizes that other vessel discharges, such as bilgewater; stern tube packing gland 

effluent; fish hold effluent; and discharges from vessel hulls, propellers, and other exposed 

surfaces are also potential vectors for the spread of aquatic invasive species. EPA excluded any 

aquatic invasive species characterization as part of this study in consideration of overall program 

schedule and resources. 

2.3.4 Application to Other Vessels, Including Larger Vessels Not Sampled for this 

Study 

EPA’s primary objective in conducting the vessel sampling program was to characterize 

discharges specific to commercial fishing vessels and nonrecreational vessels less than 79 feet 

(i.e., study vessels). Some data are applicable to other vessels, however, including larger vessels 

not sampled for this study. This subsection discusses EPA’s consideration of the applicability of 

63 
Chapter 2 – Study Design 

64 

these sample data to other vessels, as well as factors that data users should consider in 

determining the broader applicability of the data. 

Bilgewater. 

The composition and volume of bilgewater is highly dependent on the specific sources of 

wastewater that accumulate in bilge, as well as vessel size, hull design and construction, vessel 

operation, and a variety of additional factors (see Section 1.3). Any researcher, regulator, or 

other stakeholder who subsequently uses the data collected in this study should evaluate and 

compare the characteristics of the vessels sampled for this study to those of other vessels to 

determine the applicability of EPA’s sampling data. In general, EPA believes that the design, 

construction, and operation of vessels not sampled for this study (e.g., cruise ships, ferries, 

barges, tankers) differ considerably from those of the sampled vessels, which would result in 

significantly different bilgewater characteristics. Hence, EPA cautions against applying the 

limited bilgewater results from this study to all vessels. 

Stern tube packing gland effluent. 

This discharge applies to vessels that collect the ambient water that leaks through the 

stuffing box and packing gland that surround the propeller shaft in a segregated area from the 

general bilge. During this study, EPA observed this segregated discharge onboard tugboats but 

not on any other vessel classes. On tugboats, the stuffing box is packed with greased flax rings. 

EPA’s stern tube packing gland effluent data should be applicable to other vessel classes (if any) 

that use this same type of stern tube packing gland and that collect the resulting wastewater for 

segregated discharge. 

Deck runoff and/or washdown. 

Factors contributing to the volume and composition of deck runoff and/or washdown 

include deck equipment and operations, deck surface material, and method of washing the deck 

(see Section 1.3). Data users should evaluate and compare the characteristics of the vessels 

sampled for this study to those of other vessels to determine the applicability of EPA’s sampling 

data. In general, EPA believes that deck operations performed on vessels outside the scope of 

this study differ significantly from those of the sampled vessels. For example, deck washdown 

generated by fishing vessels might be applicable only to this industry, particularly in cases where 

these vessels are washing significant organic material from fishing operations overboard. As 

another example, only one sampled vessel, a supply boat, is used to support the transfer and 

handling of non-fish cargo. On the other hand, deck washdown from sampled passenger vessels 

might apply to other vessels, such as larger tour boats, water taxis, and possibly cruise ships.
Chapter 2 – Study Design 

Fish hold effluent (including both refrigerated seawater effluent and ice slurry) and effluent from 

the cleaning of fish holds. 

Since only commercial fishing vessels or tenders use fish holds for storing seafood 

products or fish, EPA believes that fish hold effluent discharges are unique to commercial 

fishing operations and are not applicable to other vessels. 

Graywater. 

The graywater sources sampled by EPA for this study are “domestic” in nature, such as 

sink water from washing hands and dishes, wastewater from shower stalls, and laundry water 

from domestic washing machines. EPA cautions the data user against applying these sampling 

data to non-domestic graywater operations, such as large-scale industrial dishwashing and 

laundry equipment. In addition, the graywater sources sampled by EPA were discharged 

immediately upon generation; therefore, these data do not represent graywater that has been 

retained in collection or storage tanks or graywater mixed with sewage. Finally, EPA’s 

graywater data do not apply to wastewater discharges from food waste processing operations, 

such as food grinders or food pulping systems. 

Propulsion and generator engine effluent. 

For this study, EPA sampled propulsion and generator effluent from a large number and 

variety of engines. These include: 

 Inboard and outboard. 

 Two-stroke and four-stroke. 

 Spark ignition and compression ignition. 

 Diesel- and gasoline-fueled. 

 New and existing. 

 Direct cooling systems (raw water directly cools the engine) and indirect cooling 

systems (raw water cools antifreeze, which cools the engine). 

 With and without wet engine exhausts (some raw water is injected into the exhaust to 

cool and quiet the exhaust). 

 Variety of manufacturers, sizes, and engine horsepower. 

 Operation at varying engine power levels (i.e., idle, slow troll, half throttle, threequarters throttle, and full throttle) depending on vessel use. 

EPA also observed a number of vessels, such as tug boats and larger commercial fishing 

vessels, that use keel-cooled propulsion engines and generators. The closed-loop cooling systems 

used on these engines do not discharge any wastewater. 

Based on an evaluation of the engine effluent sampling results, EPA observed significant 

differences in the nature and composition of discharges from inboard and outboard propulsion 

engines and from generators. EPA may also have observed differences between diesel- and 

65 
Chapter 2 – Study Design 

gasoline-fueled inboard propulsion engines; however, the data set was too small to be 

conclusive. Based on these findings, EPA believes the engine effluent data are applicable only to 

engines of similar types, specifically inboard propulsion versus outboard propulsion versus 

generators and diesel- versus gasoline-fueled engines. 

Firemain systems. 

EPA sampled relatively few firemain systems for this study. Firefighting equipment 

requirements are specified by the U.S. Coast Guard and differ by vessel type, size, construction 

(e.g., open decks versus enclosed spaces with potential to entrap explosives, flammable gases, or 

vapors), whether or not the vessel carries passengers for hire, and many other factors. Not all 

vessels within the scope of this study are required to carry firefighting equipment. For those 

vessels that require firefighting equipment, these requirements are often satisfied by carrying 

hand-portable fire extinguishers rather than firemain systems. For vessels outfitted with firemain 

systems, the systems are used during emergency and testing. None of the vessels visited by EPA 

for this study tests its firemain system more frequently than once every two weeks, and none 

operates its system for secondary purposes such as deck washing. Operating personnel from 

three tour boats and two tugboats that EPA visited agreed to engage their firemain systems for 

EPA sampling. Most operated wet rather than dry systems. The resulting sampling data apply 

primarily to wet-type firemain systems that are operated infrequently, with intake provided by 

surrounding water and without additions to the discharge (e.g., no addition of foam-forming 

agents). 

Firemain System on a Passenger Vessel Firemain System on a Passenger Vessel. 

 

EPA also sampled the firefighting system onboard a fire boat; however, these sampling 

data may only apply to fire boats or other vessels equipped with high-pressure/high-volume fire 

pumps. 

66 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

CHAPTER 3 

ANALYSIS OF DISCHARGES AND POTENTIAL IMPACT TO 

HUMAN HEALTH AND THE ENVIRONMENT 

This chapter summarizes the results of the wastewater characterization data for the nine 

types of vessel discharges sampled from the 61 vessels identified in Chapter 2. It includes the 

characterization of the nature, type, and composition of discharges for each class of vessel, as 

well as other relevant information collected regarding shipboard processes, equipment, materials, 

and operations that might contribute to the level or explain the presence of pollutants in these 

discharges. 

This chapter begins with a description of the approach used for the analyses of 

contaminants in the various discharges of the vessel classes of interest in this sampling program, 

and the specific procedures used to reduce, present, and interpret these data. Each section in the 

chapter presents and discusses in detail the results found for each discharge type selected for 

evaluation in the vessel classes of interest and summarizes the major findings for the discharges 

associated with each major vessel type. The final section discusses anti-foulant hull coating, 

which warrants discussion based on the results of other studies conducted on this discharge type 

even though EPA did not sample this discharge in this study. 

3.1 APPROACH TO ANALYSES

 EPA’s approach was designed to ensure that the analyses conducted under this study 

would be as comprehensive as possible and provide results that would represent the different 

vessels and discharges to the greatest extent possible. EPA included the discharge data collected 

from the vessels selected for this study (primary data) and any relevant data collected from other 

studies (secondary data) (e.g., engine effluent from small Armed Forces vessels covered under 

EPA’s sampling program for the Uniform National Discharge Standards (UNDS) rulemaking). 

Where appropriate, EPA also assessed ambient (harbor) and potable waters at each geographic 

location where vessels were sampled. 

EPA’s analysis attempted to make full use of the primary and secondary data collected 

for this study, including data collected from ambient (harbor) and source (vessel service1

 or city 

water supply) waters. However, EPA recognizes that the analyses are based on a limited number 

of samples; in some cases, on a sample size of fewer than five. These results should be regarded 

as preliminary in nature due to statistical considerations related to small sample sizes. 

 

1

 Service water here means the vessel potable water supply. For study vessels, vessel service water generally 

originates from municipal water supply rather than produced on board. 

67 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

EPA also attempted to identify where the analyses and results from this study could be 

reasonably extrapolated to vessels other than those vessels sampled in this study. Many of the 

discharges are not unique to vessels subject to the P.L. 110-299 moratorium in terms of the 

expected pollutants or volumes and may also be found on larger nonrecreational vessels or 

recreational vessels.

3.1.1 Data Reduction and Presentation

EPA compiled the data collected for the nine vessel discharges sampled from the 61 

vessels (see Chapter 2, Section 2.2.5.3) into a Microsoft (MS) Access database developed 

specifically for this study. For each discharge type, EPA reduced the data for summary according 

to the following procedure. 

First, data were retrieved from MS Access by discharge group, using a query developed 

specifically for this task. The queried data included the analytical result with the corresponding 

screening benchmark (defined in Section 3.1.3) and ambient and source water concentrations. 

For each discharge group, the queried data were exported to MS Excel, and then resaved as tabdelimited ASCII text (*.txt) files. Record counts were compared between the discharge groupfiltered MS Access query and the MS Excel and ASCII files to ensure that data were not lost. 

The ASCII data for each discharge group were read into an Interactive Data Language 

(IDL) (Research Systems Inc., 2003) program that carried out a series of calculations for each 

analyte, based on the following algorithm: 

1. Identify and average concentrations measured for field replicate samples, including 

replacing below-detection concentrations with 1/2 of the reporting limit2

 when at least 

one replicate was detected. 

2. Identify and average concentrations measured for laboratory replicate samples, including 

replacing below-detection concentrations with 1/2 of the reporting limit when at least one 

replicate was detected. 

3. Identify and average concentrations measured for vessel replicate samples (e.g., multiple 

deck wash, graywater, engine effluent samples from a single vessel), including replacing 

below-detection concentrations with 1/2 of the reporting limit when at least one replicate 

was detected. 

4. Calculate potential hazard quotients (PHQs) by dividing the vessel average concentration 

by the corresponding screening benchmark, if one was available (see further details 

provided in Section 3.1.3). 

 

2

 Laboratory analyses for low concentration pollutants report a detection limit (the presence or absence of a 

pollutant) and a reporting limit (the level at which the concentration of a pollutant can be quantified with appropriate 

certainty). Statistical methods often require replacement of values that are below the detection and reporting limits 

of an analytical method (especially for zero values). EPA has established conventions on how to conduct this 

replacement. In this study, certain labs were able to provide a reporting limit for only certain analytes, which is not 

uncommon. For consistency, EPA chose to use a convention of replacing the nondetects with a value of 1⁄2 of the 

reporting limit. These are referred to as replacement values below. 

68 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

5. Output vessel-average results to a comma-separated value (CSV) text file. 

6. Calculate nonparametric percentiles of the distribution of vessel-average analyte 

concentrations using the algorithm of Hyndman and Fan (2003). Note that belowdetection vessel average concentrations were not replaced at this step. 

7. Replace below-detection vessel average concentrations for those analytes where at least 

one concentration was detected with 1/2 of the reporting limit. Calculate detected 

proportion of vessel concentrations for each analyte. 

8. Output vessel-average results to a CSV text file. 

9. Calculate average discharge group analyte concentrations from the vessel average 

concentrations, including replacement values. 

10. Output statistics for each analyte (number of samples, number and proportion detected, 

average, and nonparametric percentiles) to a CSV text file. 

11. Read vessel-average results (including replacement) into SYSTAT Version 6.1 (SPSS, 

1996) to generate box and density plots for each analyte class (see Section 3.2.1 below). 

12. Read these results into MS Excel and then reassemble into a workbook with the database 

query exported from MS Access. Generate summary data tables from these workbooks. 

13. For each discharge category, reproduce by hand the data reduction and statistical 

calculations identified above for two or more randomly selected analytes as a QA 

procedure. 

All discharge-specific analytes summarized in subsequent sections of this chapter are 

organized into the following major groups: classical pollutants3

, metals, nonylphenols, nutrients, 

pathogen indicators, semivolatile organic compounds, and volatile organic compounds. For each 

discharge type, the analyte groups are generally presented according to the order of highest 

expected significance or risk in that specific discharge (e.g., the graywater section begins with 

pathogen indicators). The specific list of target analytes by group is provided in Appendix D. 

EPA did not analyze all vessel discharges for all selected analyte groups; see Table 2.2 for target 

analyte groups by discharge type. 

3.1.2 Summary Statistics and Box Plots 

This chapter includes, for each analyte group within a specific discharge type (e.g., 

bilgewater, deck washdown water), tables that summarize the number of samples analyzed, the 

number of times a specific analyte within an analyte group was detected, the average 

concentration (when only one sample was analyzed, the average is equal to the measurement), 

and additional standard summary statistics related to the measured analyte concentrations 

(median, min, max and selected (10th, 25th, 75th, and 90th) percentiles). These additional statistics 

were only calculated when a sufficient number of samples had detected values for any given 

 

3

 The classical pollutants group of analytes combines several standard water quality parameters such as conductivity, 

salinity, temperature, etc. with other parameters EPA defines as conventional pollutants (biochemical oxygen 

demand (BOD), total suspended solids (TSS), pH, fecal coliform, and oil and grease). For convenience, this group 

also includes other common analytes such as total residual chlorine, or TRC. For simplicity, these conventional and 

other common analytes and water quality parameters have all been grouped under the term "classical pollutants.” 

69 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

analyte (usually five detected values or greater). In cases where some of the concentrations of an 

analyte were reported as nondetect (censored), the concentration of that sample was estimated as 

1⁄2 of the reporting limit for purposes of calculating average concentrations4

. 

In addition to the summary tables, this section includes figures that graphically present 

the analyte-specific concentrations that were detected (as well as any replacement values for 

nondetects) for each analyte group within a discharge to better identify data trends related to 

analytes of potential concern. These figures are shown as box and dot plots, with the names of 

the analytes along the x (independent)-axis 

and their associated vessel average 

concentrations along the y(dependent)-

axis. 

For box plots, the bottom and top 

of the box displays the 25th and 75th

percentile concentrations defined as the 

interquartile range or IQR (i.e., the “box” 

contains 50 percent of the data values), 

respectively. The median is displayed as 

the horizontal line within the box. The 

“whiskers” show the relative distribution 

of data points outside of the IQR and 

represent 1.5 times the IQR. 

Superimposed over each box plot are the 

actual data points, shown as small open 

circles. Circles surrounded by large circles 

are outliers greater or less than 1.5 times 

the IQR. Circles covered by asterisks are 

outliers greater or less than three times the 

IQR. 

What is a Box Plot?

A box plot is a useful, simple statistical tool used 

to show basic characteristics of a data set. A box 

plot can show the approximate center of a data set 

and how those data are spread over a range in 

values – in this case, a range of concentrations. 

Below is an example box plot indicative of the type 

of graphical data display used throughout this 

chapter. 

 

3.1.3 Calculation of Potential Hazard Quotients 

To provide a context for the level of contaminant concentrations presented, EPA used 

National Recommended Water Quality Criteria (NRWQC)5 and several other benchmarks as a 

 

4

 See footnote 2. 

5

 National Recommended Water Quality Criteria (NRWQC) include acute (short-term) and chronic (long-term) 

criteria (toxicity threshold values) for the protection of aquatic life, as well as Human Health criteria for protection 

of humans from consumption of contaminated water or contaminated water and aquatic organisms. EPA's most 

recent compilation of NRWQC (2006) is presented as a summary table containing recommended water quality 

criteria for the protection of aquatic life and human health in surface water for approximately 150 pollutants. These 

criteria are published pursuant to Section 304(a) of the Clean Water Act (CWA) and provide guidance for states and 

70 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

preliminary screen for all discharge data with the potential to cause or contribute to the 

nonattainment of a water quality standard in a given receiving water body. The “screening-level” 

benchmarks chosen for this purpose are shown in Table 3.1 at the end of this subsection, and 

generally represent EPA’s most conservative (protective) concentration available for the specific 

analyte of interest. Several “legacy” standards (for BOD, TSS and total phosphorus) are also 

included with the screening benchmarks. For BOD and TSS, these benchmarks are EPA’s 

secondary treatment effluent limits for sewage treatment plants6. For total phosphorus, the 

benchmark of 0.1 mg/L is from EPA’s Gold Book (USEPA, 1986b) and represents a 

concentration recommended to prevent nuisance algal blooms resulting from eutrophication in 

flowing waters. EPA did not consider it appropriate to apply ecoregional nutrient criteria for this 

project. 

EPA’s NRWQC are recommended concentrations of analytes in a water body that are 

intended to protect human health, aquatic organisms and the water body uses from unacceptable 

effects from exposures to these pollutants. The NRWQC are not directly related to analyte 

concentrations in a discharge for a number of reasons. First, NRWQC not only have a 

concentration component, but also a duration and frequency component. Second, it is not always 

necessary to meet all water quality criteria within the discharge pipe to protect the integrity of a 

water body (USEPA, 1991). Under EPA’s regulations at 40 CFR 122.44(d)(1)(ii), when 

determining whether a discharge causes, has the reasonable potential to cause, or contributes to 

an in-stream excursion above a narrative or numeric criteria within a state water quality standard, 

the permitting authority will use procedures that account for, where appropriate, the dilution of 

the effluent in the receiving water. A mixing zone allows for ambient concentrations above the 

criteria in small areas near outfalls while dilution occurs. To ensure mixing zones do not impair 

the integrity of the water body, the permitting authority will determine the mixing zone such that 

it does not cause lethality to passing organisms and, considering likely pathways of exposure, 

significant human health risks. 

 tribes to use in adopting water quality standards. EPA’s 2006 NRWQC are available at: 

http://www.epa.gov/waterscience/criteria/wqctable/, hereafter referred to as EPA’s 2006 NRWQC. 6

 Secondary treatment standards for sewage treatment plants were technology-based limits developed in the late 

1970s and early 1980s, and are not the same as the water-quality-based criteria in the 2006 NRWQC. Thus, the 

PHQs for BOD and TSS calculated as described below are not directly comparable to the PHQs based on criteria 

designed to protect aquatic life or human health but, by design, such standards are imposed to limit ecological 

impacts.

71 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Nevertheless, comparing analyte concentrations in vessel discharges to NRWQC (or 

other equivalent screening benchmark) provides a conservative screen of whether these 

discharges cause, have the reasonable potential to cause, or contribute to nonattainment of the 

water quality standards in a water body. EPA calculated hazard quotients (HQs) by dividing the 

concentration of a particular analyte7

 by its corresponding water quality criterion or other 

benchmark as an initial screen for the discharge-specific water sample data. If the concentration 

of a given analyte in vessel discharge is less than the applicable screening criterion or benchmark 

values (HQ<1), the discharge would 

likely not cause, have the reasonable 

potential to cause, or contribute to 

nonattainment of a water quality 

standard based on that value, 

particularly after considering 

assimilation and/or dilution by the 

receiving water. If the HQ value is 

greater than one, then there is the 

possibility of ecological or human 

health risk as the concentration of a 

given analyte in vessel discharge is greater than the applicable screening criterion or benchmark 

values (USEPA, 1997). However, because discharges in this study are measured at the “end of 

pipe” before being released into a harbor where they are subsequently diluted, HQ values of 

greater than one do not necessarily indicate that a discharge poses a significant risk or would be 

likely to cause or contribute to a water quality standard exceedance. Further, the presence of 

additional environmental factors such as dissolved organic carbon can reduce the toxicity of 

certain pollutants (e.g., metals and many organic pollutants) and reduce the likelihood of 

ecological or health risk. Because of these additional considerations, EPA uses the term potential 

hazard quotients (PHQs) instead to indicate this difference, as the PHQs are only intended to 

indicate that a screening benchmark was exceeded and the discharge thus warrants further 

consideration regarding the potential to cause or contribute to nonattainment of water quality 

standards8

. 

Mobile sources such as vessels complicate the analysis because they discharge into many 

different water bodies, but in general, greater mixing and dilution would be expected for 

discharges from vessels than from stationary sources when they are in motion while discharging. 

EPA acknowledges that vessel discharges to areas with high vessel traffic, areas with a low 

Mitigating Conditions/Circumstances in a Water Body

Compared to the volume of a typical harbor, the effluent 

volume of any particular vessel discharge is small (see 

Chapter 4). Therefore, even when pollutant concentrations 

of a particular effluent are high, the total loading of that 

pollutant on the receiving water of the harbor can be 

relatively small. Furthermore, most harbors are continually 

flushed by freshwater and tidal activity. These dilution 

factors, in addition to the mitigating capacity of saltwater 

cations and organic matter, may reduce the toxicity of 

many of these pollutants.

 

7

 PHQs were also calculated using replacement values for nondetected concentrations, so that such results would be 

represented in the box and scatter plots. Note: all PHQ values in box plots that were calculated with replacement 

values throughout this chapter are circled. 

8

 EPA does not consider a PHQ that exceeds 1 to signal that these discharges pose a potential risk to cause or 

contribute to the non-attainment of a water quality standard when the PHQ is based on replacement values for 

nondetected concentrations. 

72 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

degree of flushing, or impaired water bodies could reduce mixing and dilution. With these 

factors in mind and assuming the data from this study are representative of the class of vessels as 

a whole, a PHQ marginally above a value of 1 is most likely not of significant concern. On the 

other hand, a PHQ value substantially above 1 (e.g., 10 or 100) may be more likely to be of 

concern, particularly if the discharge is of significant volume, is in an area of low flushing, is in 

an area where there is a high degree of vessel traffic, or is in a waterbody that is already impaired 

or under other stress. 

 EPA recognizes that one of the key factors in evaluating metal toxicity is the 

bioavailability of the metal to an organism. Exposure to metals at toxic levels can cause a variety 

of changes in biochemical, physiological, morphological, and behavioral patterns in aquatic 

organisms. In the aquatic environment, elevated concentrations of dissolved metals can be toxic 

to many species of algae, crustaceans, and fish. Some metals have a strong tendency to adsorb to 

suspended organic matter and clay minerals or to precipitate out of solution, thus removing the 

metal from the water column. The tendency of a given metal to adsorb to suspended particles is 

typically controlled by the pH and salinity of the water body, as well as the organic carbon 

content of the suspended particles. If the metal is highly sorbed to particulate matter, then it is 

not likely to be in a dissolved form that aquatic organisms can process (i.e., bioavailable)9

. 

 Accordingly, NRWQC for the protection of aquatic life for metals are typically expressed 

in the dissolved form. Therefore, a high concentration of a metal measured in its total form 

(dissolved and particulate) may not be an accurate representation of its toxic potential to aquatic 

organisms. In contrast, human health criteria (for the consumption of organisms) for metals are 

commonly expressed in the total metal form because human exposure to pollutants is assumed to 

be through the consumption of organisms, where the digestive process is assumed to transform 

all forms of metals to the dissolved phase, thus increasing the amount of biologically available 

metals. EPA was mindful of this distinction between aquatic life and human health criteria for 

metals when comparing the dissolved and total metals concentration data in the various 

discharges to NRWQC and when calculating PHQs using the screening benchmarks. In 

particular, in considering the potential for vessel discharges to pose a risk to human health, EPA 

also noted the likelihood of human exposure to such discharges (e.g., potential for receiving 

water to be used as drinking water source). 

 

9

 Note that the bioavailability of metals is a relative term and depends on many factors. For example, particulate 

metals complexed to suspended organic matter or clay minerals may be recycled into the water column and become 

bioavailable due to physical resuspension (dredging activities) of bed sediments or bioturbation (the stirring or 

mixing of sediment particles by benthic animals). Depending on conditions in the water column and microbiological 

activity within the surficial sediment and overlying water surface layers, these physical and biological actions might 

remobilize the metals in the dissolved bioavailable form for potential uptake by aquatic organisms. Likewise, certain 

benthic organisms called deposit feeders might consume particulate-bound metals and re-release metals via 

digestion and excretion or introduce metals into the food chain when consumed by predators. 

73 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

EPA chose to include the major cations calcium, magnesium, potassium and sodium in 

the metals analysis to further characterize the vessel discharges. As common ions in surface 

waters, the concentrations of these ions are indicative of the sample matrix (i.e., freshwater, 

saltwater, brackish water) rather than pollutant loadings. Accordingly, major cation 

concentrations are typically elevated (up to three orders of magnitude higher) relative to other 

metals included in the metals analysis (e.g., copper, lead, and zinc). For example, the typical 

concentrations of major cations in full and partial (brackish) strength seawater and in freshwater 

of various total water hardness levels are listed in Tables 3.2 and 3.3 below. Major cations are 

not toxic except at extreme, uncommon levels. 

 For convenience, data tables for metals in this chapter segregate the presentation of major 

cation concentration data from that of the other metals to clearly distinguish between the 

naturally occurring cations and other metals of potential concern in vessel discharges. It is worth 

noting that many of the samples collected for this study consist entirely or partially of sea water; 

consequently, these samples can have high concentrations of components (e.g., salts) that can 

interfere with the analytical measurement of the chemical of interest. EPA evaluated whether 

measured concentrations of selenium and arsenic may have exhibited “positive interference” 

(i.e., the measured concentration is higher than the actual concentration in the sample – see text 

box for more technical information). EPA found that trace metal analysis using a conventional 

ICP-MS-based analytical method may have resulted in positive interference for some samples of 

selenium, and to a lesser extent, arsenic. However, for the majority of samples analyzed in this 

study, either the samples contained few interferences (i.e., samples were from freshwater) or 

alternate instrumentation, which had the capability of minimizing sample interferences, was used 

for analyte measurement. Hence, the majority of arsenic and selenium results did not have 

positive interference. EPA identified 

the few samples analyzed using the 

conventional ICP-MS method, which 

may have yielded artificially high 

values for the measured concentration 

of arsenic and selenium. Therefore, 

while such positive interferences were 

not found to influence the overall 

findings presented in this study, the 

selenium and arsenic concentrations 

potentially affected by positive 

interference are identified (noted by 

footnote in each instance) throughout 

this chapter. 

Explanation of Possible Positive Interference on Select 

Arsenic and Selenium Measurements

Positive interference occurs when components of a 

sample, other than the analyte, affect the measurement of 

the analyte of interest by yielding an artificially high value. 

This occurs when components in the sample interfere with 

the analytical methodology. Some of the components of 

sea water (e.g., calcium, magnesium, potassium, sodium), 

are known to cause positive interference with certain trace 

elements, such as arsenic and selenium. The potential for 

interference is based on the analytical method and 

instrumentation used for the measurement. In these 

situations, alternate sample preparation or analytical 

instrumentation may be required to eliminate or reduce 

sample interferences, in order to maintain analyte 

sensitivity. 

74 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Table 3.1. Water Quality and Other Benchmark Values Used to Screen the Vessel 

Discharge Data 

Analyte Screening 

Benchmarks Units Source1

1,1,2,2-Tetrachloroethane 0.17 μg/L 2006 NRWQC HH W+O 

1,1,2-Trichloroethane 0.59 μg/L 2006 NRWQC HH W+O 

1,1-Dichloroethene 330 μg/L 2006 NRWQC HH W+O 

1,2,4,5-Tetrachlorobenzene 0.97 μg/L 2006 NRWQC HH W+O 

1,2,4-Trichlorobenzene 35 μg/L 2006 NRWQC HH W+O 

1,2-Dichlorobenzene 420 μg/L 2006 NRWQC HH W+O 

1,2-Dichloroethane 0.38 μg/L 2006 NRWQC HH W+O 

1,2-Dichloropropane 0.5 μg/L 2006 NRWQC HH W+O 

1,2-Diphenyl hydrazine 0.036 μg/L 2006 NRWQC HH W+O 

1,3-Dichlorobenzene 320 μg/L 2006 NRWQC HH W+O 

1,3-Dichloropropane 0.34 μg/L 2006 NRWQC HH W+O 

1,4-Dichlorobenzene 63 μg/L 2006 NRWQC HH W+O 

2,3,7,8-TCDD (Dioxin) 5.0E-09 μg/L 2006 NRWQC HH W+O 

2,4,5-Trichlorophenol 1800 μg/L 2006 NRWQC HH W+O 

2,4,6-Trichlorophenol 1.4 μg/L 2006 NRWQC HH W+O 

2,4-Dichlorophenol 77 μg/L 2006 NRWQC HH W+O 

2,4-Dimethylphenol 380 μg/L 2006 NRWQC HH W+O 

2,4-Dinitrophenol 69 μg/L 2006 NRWQC HH W+O 

2,4-Dinitrotoluene 0.11 μg/L 2006 NRWQC HH W+O 

2-Chloronaphthalene 1000 μg/L 2006 NRWQC HH W+O 

2-Chlorophenol 81 μg/L 2006 NRWQC HH W+O 

2-Methyl-4,6-Dinitrophenol 13 μg/L 2006 NRWQC HH W+O 

3,3'-Dichlorobenzidine 0.021 μg/L 2006 NRWQC HH W+O 

4,4'-DDD 0.00031 μg/L 2006 NRWQC HH Org Only 

4,4'-DDE 0.00022 μg/L 2006 NRWQC HH Org Only 

4,4'-DDT 0.0010 μg/L 2006 NRWQC CCC 

4,6-Dinitro-2-methylphenol 13 μg/L 2006 NRWQC HH W+O 

Asbestos 7000000 fibers/L 2006 NRWQC HH W+O 

Acenaphthene 670 μg/L 2006 NRWQC HH W+O 

Acrolein 6.0 μg/L 2006 NRWQC HH W+O 

Acrylonitrile 0.051 μg/L 2006 NRWQC HH W+O 

Aldrin 1.3 μg/L 2006 NRWQC SW CMC 

Alkalinity 20000 μg/L 2006 NRWQC FW CCC 

alpha-BHC 0.0026 μg/L 2006 NRWQC HH W+O 

alpha-Endosulfan 0.0087 μg/L 2006 NRWQC SW CCC 

Aluminum, Total 87 μg/L 2006 NRWQC FW CCC 

Ammonia As Nitrogen (NH3-N) 1.2 mg/L 2006 NRWQC SW CCC 

Anthracene 8300 μg/L 2006 NRWQC HH W+O 

Antimony, Total 5.6 μg/L 2006 NRWQC HH W+O 

Arsenic, Total 0.018 μg/L 2006 NRWQC HH W+O 

Arsenic, Dissolved 36 μg/L 2006 NRWQC SW CCC 

Barium, Total 1000 μg/L 2006 NRWQC HH W+O 

Benzene 2.2 μg/L 2006 NRWQC HH W+O 

Benzidine 0.000086 μg/L 2006 NRWQC HH W+O 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Screening Source1 Analyte Units Benchmarks 

Benzo(a)Anthracene 0.0038 μg/L 2006 NRWQC HH W+O 

Benzo(a)Fluoranthene 0.0038 μg/L 2006 NRWQC HH W+O 

Benzo(a)pyrene 0.0038 μg/L 2006 NRWQC HH W+O 

Benzo(b)fluoranthene 0.0038 μg/L 2006 NRWQC HH W+O 

Benzo(k)Fluoranthene 0.0038 μg/L 2006 NRWQC HH W+O 

beta-BHC 0.0091 μg/L 2006 NRWQC HH W+O 

beta-Endosulfan 0.0087 μg/L 2006 NRWQC SW CCC 

Biochemical Oxygen Demand (BOD) 30 mg/L 1984 Secondary Treatment Effluent Limits 

Bis (2-Chloroethyl) ether 0.030 μg/L 2006 NRWQC HH W+O 

Bis (2-chloroisopropyl)ether 1400 μg/L 2006 NRWQC HH W+O 

Bis(2-Chloroethyl)ether 0.030 μg/L 2006 NRWQC HH W+O 

Bis(2-Ethylhexyl) phthalate 1.2 μg/L 2006 NRWQC HH W+O 

Bromodichloromethane 0.55 μg/L 2006 NRWQC HH W+O 

Bromoform 4.3 μg/L 2006 NRWQC HH W+O 

Bromomethane 47 μg/L 2006 NRWQC HH W+O 

Butyl benzyl Phthalate 1500 μg/L 2006 NRWQC HH W+O 

Cadmium, Dissolved 0.25 μg/L 2006 NRWQC FW CCC 

Carbon tetrachloride 0.23 μg/L 2006 NRWQC HH W+O 

Chlordane 0.0040 μg/L 2006 NRWQC SW CCC 

Chloride 230000 μg/L 2006 NRWQC FW CCC 

Chlorobenzene 130 μg/L 2006 NRWQC HH W+O 

Dibromochloromethane 0.40 μg/L 2006 NRWQC HH W+O 

Chloroform 5.7 μg/L 2006 NRWQC HH W+O 

Chlorophenoxy Herbicide (2,4,5,-TP) 10 μg/L 2006 NRWQC HH W+O 

Chlorophenoxy Herbicide (2,4-D) 100 μg/L 2006 NRWQC HH W+O 

Chloropyrifos 0.0056 μg/L 2006 NRWQC SW CCC 

Chromium, Dissolved 11 μg/L 2006 NRWQC FW CCC 

Chrysene 0.0038 μg/L 2006 NRWQC HH W+O 

Copper, Dissolved 3.1 μg/L 2006 NRWQC SW CCC 

Copper, Total 1300 μg/L 2006 NRWQC HH W+O 

Cyanide 1.0 μg/L 2006 NRWQC SW CMC 

Demeton 0.10 μg/L 2006 NRWQC FW and SW CCC 

Diazinon 0.17 μg/L 2006 NRWQC FW CMC and CCC 

Dibenz(a,h)Anthracene 0.0038 μg/L 2006 NRWQC HH W+O 

Chlorodibromomethane 0.40 μg/L 2006 NRWQC HH W+O 

Dichlorobromomethane 0.55 μg/L 2006 NRWQC HH W+O 

Dieldrin 0.0019 μg/L 2006 NRWQC SW CCC 

Diethyl Phthalate 17000 μg/L 2006 NRWQC HH W+O 

Dimethyl phthalate 270000 μg/L 2006 NRWQC HH W+O 

Di-n-butyl phthalate 2000 μg/L 2006 NRWQC HH W+O 

Dinitrophenols 69 μg/L 2006 NRWQC HH W+O 

E. Coli by MPN 126 MPN/100 ml 1986 NRWQC B FW 

Endosulfan Sulfate 62 μg/L 2006 NRWQC HH W+O 

Endrin 0.0023 μg/L 2006 NRWQC SW CCC 

Endrin Aldehyde 0.29 μg/L 2006 NRWQC HH W+O 

Enterococci by MPN 33 MPN/100 ml 1986 NRWQC B FW 

Ether, Bis(Chloromethyl) 0.00010 μg/L 2006 NRWQC HH W+O 

Ethylbenzene 530 μg/L 2006 NRWQC HH W+O 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Screening Source1 Analyte Units Benchmarks 

Fecal Coliform by MF 14 MPN/100 ml 1976 QCW SH 

Fluoranthene 130 μg/L 2006 NRWQC HH W+O 

Fluorene 1100 μg/L 2006 NRWQC HH W+O 

Gamma-BHC (Lindane) 0.16 μg/L 2006 NRWQC SW CMC 

Guthion 0.010 μg/L 2006 NRWQC FW and SW CCC 

Heptachlor 0.0036 μg/L 2006 NRWQC SW CCC 

Heptachlor Epoxide 0.0036 μg/L 2006 NRWQC SW CCC 

Hexachlorobenzene 0.00028 μg/L 2006 NRWQC HH W+O 

Hexachlorobutadiene 0.44 μg/L 2006 NRWQC HH W+O 

Hexachlorocyclo-hexane-Technical 0.0123 μg/L 2006 NRWQC HH W+O 

Hexachlorocyclopentadiene 40 μg/L 2006 NRWQC HH W+O 

Hexachloroethane 1.4 μg/L 2006 NRWQC HH W+O 

Hexane Extractable Material (HEM) 15 mg/L MARPOL 73/78 

Ideno(1,2,3-cd)Pyrene 0.0038 μg/L 2006 NRWQC HH W+O 

Iron, Total 300 μg/L 2006 NRWQC HH W+O 

Isophorone 35 μg/L 2006 NRWQC HH W+O 

Lead, Dissolved 2.5 μg/L 2006 NRWQC FW CCC 

Malathion 0.1 μg/L 2006 NRWQC FW and SW CCC 

Manganese 50 μg/L 2006 NRWQC HH W+O 

Mercury 0.77 μg/L 2006 NRWQC FW CCC 

Methoxychlor 0.03 μg/L 2006 NRWQC SW CCC 

Methylene chloride 4.6 μg/L 2006 NRWQC HH W+O 

Mirex 0.001 μg/L 2006 NRWQC FW and SW CCC 

Nickel, Dissolved 8.2 μg/L 2006 NRWQC SW CCC 

Nickel, Total 610 μg/L 2006 NRWQC HH W+O 

Nitrates 10000 μg/L 2006 NRWQC HH W+O 

Nitrobenzene 17 μg/L 2006 NRWQC HH W+O 

Nitrosamines 0.0008 μg/L 2006 NRWQC HH W+O 

Nitrosodibutylamine,N 0.0063 μg/L 2006 NRWQC HH W+O 

Nitrosodiethylamine,N 0.0008 μg/L 2006 NRWQC HH W+O 

Nitrosopyrrolidine,N 0.016 μg/L 2006 NRWQC HH W+O 

N-Nitroso Di-n-propylamine 0.005 μg/L 2006 NRWQC HH W+O 

N-Nitrosodimethylamine 0.00069 μg/L 2006 NRWQC HH W+O 

N-Nitrosodiphenylamine 3.3 μg/L 2006 NRWQC HH W+O 

Parathion 0.013 μg/L 2006 NRWQC FW CCC 

Pentachlorobenzene 1.4 μg/L 2006 NRWQC HH W+O 

Pentachlorophenol 7.9 μg/L 2006 NRWQC SW CCC 

Phenol 21000 μg/L 2006 NRWQC HH W+O 

Phorphorus (as phosphate) 0.1 mg/L EPA 1986 Goldbook 

Polychlorinated Biphenyls (PCBs) 0.000064 μg/L 2006 NRWQC HH W+O 

Pyrene 830 μg/L 2006 NRWQC HH W+O 

Selenium, Dissolved 5 μg/L 2006 NRWQC FW CCC 

Selenium, Total 170 μg/L 2006 NRWQC HH W+O 

Silica Gel Treated HEM (SGT-HEM) 15 mg/L MARPOL 73/78 

Silver, Dissolved 1.9 μg/L 2006 NRWQC SW CMC 

Solids Dissolved and Salinity 250000 μg/L 2006 NRWQC HH W+O 

Sulfide-Hydrogen Sulfide 0.002 mg/L 2006 NRWQC FW and SW CCC 

Tetrachloroethene 0.69 μg/L 2006 NRWQC HH W+O 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Screening Source1 Analyte Units Benchmarks 

Thallium, Total 0.24 μg/L 2006 NRWQC HH W+O 

Toluene 1300 μg/L 2006 NRWQC HH W+O 

Total Nonylphenols 1.7 μg/L 2006 NRWQC SW CCC 

Total Phosphorus 0.1 mg/L 1986 NRWQC 

Total Polychlorinated Biphenyls 0.000064 μg/L 2006 NRWQC HH Org Only 

Total Suspended Solids (TSS) 30 mg/L 1984 Secondary Treatment Effluent Limits 

Total Residual Chlorine (TRC) 0.0075 mg/L 2006 NRWQC SW CCC 

Toxaphene 0.0002 μg/L 2006 NRWQC FW and SW CCC 

trans-1,2-Dichloroethene 140 μg/L 2006 NRWQC HH W+O 

Tributyltin (TBT) 0.0074 μg/L 2006 NRWQC SW CCC 

Trichloroethene 2.5 μg/L 2006 NRWQC HH W+O 

Vinyl chloride 0.025 μg/L 2006 NRWQC HH W+O 

Zinc, Dissolved 81 μg/L 2006 NRWQC SW CCC 

Zinc, Total 7400 μg/L 2006 NRWQC HH W+O 

(1) Sources: 

MARPOL 73/78: International Convention for the Prevention of Pollution From Ships, 1973 as modified by the Protocol of 

1978 (MARPOL 73/88, 1978). 

1976 QCW SH (shellfish harvesting): Note MPN is most probable number and approximates the unit of measure for fecal 

coliform in this study of CFU (colony forming units) (USEPA, 1976). 

1984 Secondary Treatment Effluent Limits: 49 FR 37006, Sept. 20, 1984. 

1986 NRWQC B FW (bathing (full body contact) recreational waters – fresh water): (USEPA, 1986). 

Quality Criteria for Water 1986 (Goldbook) (USEPA, 1986b). 

2006 NRWQC FW CCC (freshwater chronic): (USEPA, 2006). 

2006 NRWQC SW CCC (saltwater chronic) (USEPA, 2006). 

2006 NRWQC SW CMC (saltwater acute) (USEPA, 2006). 

2006 NRWQC HH Org Only (human health for the consumption of organism only) (USEPA, 2006). 

2006 NRWQC HH W+O (human health for the consumption of water + organism) (USEPA, 2006). 

Table 3.2. Major Cation Concentrations in Seawater 

Seawater Salinity Level Calcium, mg/L Magnesium, mg/L Potassium, mg/L Sodium, mg/L 

Full Strength 1 (35 ppt 

salinity) 400 1,350 380 10,500 

Brackish 2 (10 ppt 

salinity) 114 386 109 3,000 

(1) Source: Mowka, 2009. 

(2) Calculated from full strength seawater concentrations, assuming dilution by ion-free water. 

Table 3.3. Major Cation Concentrations in Freshwater 

Freshwater Hardness 

Level Calcium, mg/L Magnesium, mg/L Potassium, mg/L Sodium, mg/L 

Soft (40-48 mg CaCO3/L) 1 6.99 6.06 1.05 13.1 

Moderately Hard (80-100 

mg CaCO3/L) 1 14.0 12.1 2.10 26.3 

Hard (160-180 mg 

CaCO3/L) 1 27.9 24.2 4.20 52.5 

(1) Source: USEPA, 2007. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2 CHARACTERIZATION OF DISCHARGES

Each subsection of Section 3.2 presents in detail the observed results for the discharge 

types selected for evaluation in the study vessels: bilgewater; stern tube packing gland effluent; 

deck runoff and/or washdown; fish hold effluent (both refrigerated seawater effluent and ice 

slurry) and effluent from the cleaning of fish holds; graywater; propulsion (inboard and 

outboard) and generator engine effluent; and discharges from firemain systems. Tables and 

figures are presented at the end of each subsection. 

3.2.1 Bilgewater 

Bilgewater can be found on board every vessel and describes the water that collects in the 

bottom of a vessel. This water may be from rough seas, rain, minor leaks in the hull or stuffing 

box, etc. Depending on the ship's design and function, bilgewater sometimes contains 

contaminants such as oil, fuel, graywater, detergents, solvents, chemicals, pitch, and particulates. 

For this study, EPA collected bilgewater samples from seven vessels: two tow/salvage vessels, 

two water taxis, one longline fishing vessel, one shrimping vessel, and one tour boat. 

Based on data and field observations from EPA’s vessel sampling program, as well as 

information from secondary data sources, EPA estimates many commercial vessels generate, on 

average, between 10 and 15 gallons per day (gpd) of bilgewater depending on the vessels’ 

configuration and intended use; however, EPA noted that vessels might generate as little as 2 

gallons of bilgewater or as much as 750 gallons of bilgewater per day. For vessels such as small 

tow/salvage vessels or water taxis with open bows, bilgewater pump-out can occur frequently 

throughout the day, resulting in small volumes during each pump-out cycle (1-2 gallons). Larger 

vessels such as commercial fishing boats are likely to pump less frequently due to larger storage 

capacity in the bilge; however, the bilgewater discharge volume can be hundreds of gallons. For 

example, EPA noted that a 26-foot, center console Boston Whaler being used as a tow/salvage 

vessel had accumulated only 2 gallons of bilgewater following a tow activity. However, a 62-

foot shrimp boat sampled by EPA in the Gulf of Mexico discharged approximately 750 gallons 

of bilgewater during the daily pump-out. 

In general, the volume of bilgewater generated by commercial fishing boats and 

commercial vessels depends on the following factors: 

 Hull and deck construction 

 Vessel size 

 Precipitation 

 Frequency of deck cleaning 

 Amount of spray reaching the deck(s) 

 Accidental spills 

 Integrity of hull and below-deck piping systems 

 Potential for condensate formation in below-deck areas. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Commercial vessels with open bow and stern areas (e.g., commercial fishing and 

tow/salvage vessels) have relatively large deck areas that are exposed to precipitation, spray, and 

cleaning water, which results in greater bilgewater volumes compared to vessels such as tour 

boats or water taxis that have less exposed deck. Other sources that contribute to bilgewater 

onboard commercial vessels include small leaks in potable water, graywater and sewage piping 

systems, and condensates from the interior of the hull or refrigeration systems. The volume of 

these additional bilgewater sources is also highly vessel-specific. 

In this vessel sampling program, EPA collected single grab samples of bilgewater 

discharge from selected vessels for laboratory analysis. The results of the analysis were intended 

to be representative of bilgewater pollutant concentrations over the range of normal vessel 

operations. Collecting bilgewater samples proved difficult for EPA for a number of reasons 

including: (1) automatic bilge pumps would discharge insufficient volumes of bilgewater in a 

single operating cycle, (2) vessel operators were generally reluctant to discharge bilgewater for 

fear of exceeding existing CWA § 311 requirements (oily discharges), and (3) sampling was 

often impractical because bilgewater was typically discharged via thru-hull openings located at 

or near the vessel’s waterline. 

Bilgewater samples were analyzed for a wide range of pollutants including metals, 

classical pollutants, pathogen indicators, nutrients, semivolatile and volatile organic compounds, 

and nonylphenols. Results for each class of pollutant are presented and discussed in the 

following subsections. 

3.2.1.1 Metals 

Bilgewater samples were analyzed for dissolved10 and total (dissolved plus particulate) 

concentrations of metals. The analytical results are summarized in Table 3.1.1 for dissolved 

metals and in Table 3.1.2 for total metals that were detected in at least one bilgewater sample. 

The following metals were measured in all bilgewater samples: 

 Total aluminum 

 Total arsenic11

 Dissolved and total barium 

 Dissolved and total calcium 

 Dissolved and total copper 

 Dissolved and total magnesium 

 Dissolved and total manganese 

 Dissolved and total potassium 

 

10 Dissolved metals were obtained by filtering the water sample. 11 Note that for three of the seven bilgewater samples analyzed, EPA suspects that the measured arsenic 

concentrations are likely to be overestimated due to the positive interference of major cations in seawater (see 

discussion on page 74). 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

 Dissolved and total sodium 

 Dissolved and total zinc. 

Concentrations of other metals were measured in 50 percent or more of the samples analyzed: 

 Dissolved aluminum 

 Dissolved arsenic12

 Dissolved and total chromium 

 Total iron 

 Total lead 

 Dissolved and total nickel 

 Dissolved and total 

selenium13. 

 Figure 3.1.1 presents the range 

of concentrations measured for 

dissolved metals in the bilgewater 

samples. The plots show that dissolved 

metals concentrations range over six 

orders of magnitude. Calcium, 

magnesium, potassium and sodium 

were the dissolved metals measured at 

the highest concentrations. As discussed 

in Chapter 1 and Section 3.1.3, these 

cations naturally occur in seawater and 

their levels in the discharges are similar 

to levels seen in ambient seawater. As 

many discharges use ambient water for 

onboard activities, and spray would 

contribute to other discharges, it was 

not unexpected to find these levels of 

cations in the bilgewater samples as 

most vessels were sampled in coastal 

areas. At these concentrations, these cations are generally not toxic to aquatic organisms, which 

is why there there are no NRWQC for these metals, and therefore, no PHQs were calculated (see 

Section 3.1.3 for additional explanation). Dissolved aluminum, barium, copper, manganese, 

selenium13 and zinc were also measured at relatively high concentrations (tens to hundreds of 

Dissolved versus Total Metals

EPA recommends using dissolved metal to set and 

measure compliance with water quality standards because 

dissolved metal more closely approximates the 

bioavailable fraction of metal in the water column than 

does total recoverable metal (USEPA, 1993). EPA 

considers that the primary mechanism for toxicity to 

organisms that live in the water column to be adsorption to 

or uptake across the respiratory surfaces of aquatic 

organisms (i.e., the gills) as well as the carapace of certain 

invertebrates, and this physiological process requires 

metal to be in a dissolved form. This is not to suggest that 

particulate metals are nontoxic; rather, because toxicity of 

particulate metals are primarily restricted to direct 

ingestion via dietary exposure, they are less toxic overall 

compared to dissolved metal (USEPA, 1996). There are 

exceptions, however, particularly for bottom feeding 

organisms, and for metals that bioaccumulate (also see 

footnote in Section 3.1.3 regarding physical and biological 

recycling of particulate metals). Dissolved metal is 

operationally defined as that which passes through a 0.45-

μm or a 0.40-μm filter and particulate metal is operationally 

defined as total recoverable metal minus dissolved metal. 

EPA typically uses the dissolved fraction, or fd, to express 

the fraction of the total chemical concentration in water 

that is dissolved. To calculate fd, divide the dissolved 

concentration by the total concentration. A chemical that is 

entirely in the dissolved phase has a fd of 1, while a 

chemical that is entirely in the particulate phase has a fd of 

0.

 

12 Note that for three of the six bilgewater samples where dissolved arsenic was detected, EPA suspects that the 

measured arsenic concentrations are likely to be overestimated due to positive interference (see discussion on page 

74) 

13 Note: EPA suspects positive interference for all concentrations of total and dissolved selenium detected in 

bilgewater samples (see discussion on page 74). Reported values could be entirely due to this positive interference. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

μg/L) in most bilgewater samples; dissolved arsenic14 and iron were also measured at 

concentrations greater than 100 μg/L in individual samples. Among the vessels from which 

bilgewater was sampled, a tow/salvage boat had the highest concentrations of the most dissolved 

metals (seven analytes), while the water taxi had only one dissolved metal. 

 Figure 3.1.2 shows the total metals concentrations in the bilgewater samples. The box 

plots show that the relative ranges of total metals concentrations are comparable to the 

concentrations of dissolved metals. Among the vessels from which bilgewater was sampled, the 

shrimper had the highest concentrations of the most total metals (11), while the longliner and the 

water taxi had the fewest (one each). In general, total concentrations for each metal are similar to 

or slightly higher than the dissolved concentrations. To explore this relationship further, EPA 

calculated the average dissolved fraction fd of each metal in the bilgewater samples to better 

understand the potential for aquatic organism impacts. The metals with the highest average 

dissolved fractions (fd > 90 percent) included barium, calcium, magnesium, potassium, selenium 

(see footnote 13), and zinc. Metals having intermediate average dissolved fractions (90 percent > 

fd > 50 percent) included antimony, arsenic (see footnotes 11 and 12), cadmium, chromium, 

cobalt, copper, iron, manganese, and nickel. Aluminum, lead, and vanadium had the lowest 

average dissolved fractions (fd < 50 percent). 

Figure 3.1.3 shows the distributions of PHQs based on the most conservative screening 

benchmark for each of the dissolved metals. Per Section 3.1.3 above, points on this plot above 

the dashed line (demarcating a PHQ of one) indicate a dissolved metal concentration exceeding 

the benchmark; two of the dissolved metals (cadmium and copper) have PHQs that include 

values greater than 10, indicating that the measured concentrations were one (or more) order of 

magnitude greater than the screening benchmark. EPA suspects that the high PHQs for a third 

dissolved metal in this discharge (selenium) was elevated due to positive interference due to the 

major seawater cations in these samples. The highest PHQ (113) was for dissolved copper, 

measured in the bilgewater sample from the tour boat. EPA also found PHQs exceeding one for 

dissolved arsenic, chromium, lead, nickel, and zinc, bringing to eight the number of dissolved 

metals that exceeded the most stringent 2006 NRWQC in one or more bilgewater sample. 

Dissolved copper concentrations, ranging from 6.6 to 350 μg/L, exceeded the saltwater acute 

(4.8 μg/L) and chronic (3.1 μg/L) criteria in all seven bilgewater samples; concentrations in all 

but one bilgewater sample also exceeded the freshwater acute (13 μg/L) and chronic (9 μg/L) 

criteria. The single elevated dissolved cadmium concentration (10 μg/L) exceeded the freshwater 

acute (2.0 μg/L) and chronic (0.25 μg/L) criteria, and the saltwater chronic (8.8 μg/L) criterion. 

In addition, the highest dissolved arsenic concentration (230 μg/L) exceeded the 36 μg/L 

saltwater chronic criterion. For the other dissolved metals (chromium, lead, nickel, and zinc), 

 

14 As noted in footnote 11, some dissolved arsenic samples may experience positive interference. Dissolved arsenic 

samples not suspected of having positive interference include the measured dissolved arsenic concentration of 230 

μg/L for the tow/salvage vessel, the dissolved arsenic concentration of 10 μg/L for the tour boat as well as the 

relatively low dissolved arsenic concentration of 1.1 μg/L for a sample of bilgewater from a tow/salvage vessel. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

concentrations in one or more bilgewater samples exceeded saltwater and/or freshwater criteria, 

although in each of these cases the PHQs were less than five.

Three of the total metals (aluminum, arsenic15, and iron) exceeded the most stringent 

2006 NRWQC16 in one or more bilgewater samples as shown in Figure 3.1.4. PHQs for total 

arsenic (those not suspected of significant positive interference) ranged from 306 to 16,170. The 

total arsenic concentrations in samples associated with these PHQs all greatly exceeded the 

human health criterion for consumption of water plus organism of 0.018 μg/L, as well as the 

human health criterion for organism consumption alone, 0.14 μg/L. PHQs for aluminum and iron 

did not exceed 11. Five of the seven total aluminum concentrations measured in bilgewater (at 

concentrations ranging from 332 to 940 μg/L) exceeded the freshwater chronic criterion (87 

μg/L, expressed as total recoverable metal). For total iron, concentrations in two of three 

bilgewater samples exceeded the human health criterion for water plus organism consumption of 

300 μg/L; PHQs for total iron ranged from 0.17 to 6.3. 

 To further evaluate the significance of the dissolved and total metals concentrations in the 

bilgewater samples, EPA compared them to ambient dissolved and total metal concentrations in 

surface water samples collected near the vessels. This was done because surface water might 

occasionally leak into certain vessel bilges, be used onboard the vessel, or splash onto the vessel 

and drain into the bilge. In these cases, the concentrations of metals (as well as other analytes) 

measured in the bilgewater samples might be similar to or significantly influenced by the 

ambient concentrations. Indeed, EPA found that the concentrations of many of the metals 

(including aluminum, barium, calcium, chromium, magnesium, manganese, nickel, potassium, 

selenium, and sodium) measured in multiple bilgewater samples were no more than double the 

ambient concentrations. The similarity in the concentrations of many of these metals in 

bilgewater and ambient samples suggests that some proportion of the water sampled in the vessel 

bilges may be from ambient water. It is less clear whether the significant background ambient 

metals concentrations in the sampled harbors reflect the loading from the cumulative discharges 

of the many vessels that operate there, or loadings from other point and/or nonpoint pollutant 

sources to these water bodies. 

 On the other hand, the highest concentrations of some of the dissolved and total metals 

measured in bilgewater were substantially elevated above the corresponding ambient 

concentrations. For dissolved copper, the ambient concentration that accompanied the highest 

bilgewater concentration (350 μg/L from a tour boat) was below the detection limit. The next 

two highest dissolved copper concentrations in bilgewater (119 and 120 μg/L) were from water 

taxis with a somewhat higher corresponding ambient concentration of 24 μg/L. 

 

15 Measured total arsenic concentration where no positive interference is evident include 291 μg/L for a tow/salvage 

vessel, 19 and 5.5 μg/L for the tour boat and longliner fishing vessel, respectively, and 1.3 μg/L for a sample of 

bilgewater from a tow/salvage vessel. 

16 PHQs for total metals are based on NRWQC for human health and not aquatic life, as stated in Section 3.1.3. 

83 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

84 

 For dissolved aluminum, the ambient concentration that accompanied the highest 

bilgewater concentration (520 μg/L from the longliner) was 870 μg/L; in this case, and several 

others, even the highest concentration for a metal in bilgewater was exceeded by the ambient 

concentration. 

 The data for total metals also demonstrate considerable variability in the relationships 

between bilgewater and ambient concentrations. The highest total arsenic concentration in 

bilgewater (291 μg/L from a tow/salvage boat) exceeded the corresponding ambient 

concentration (12 μg/L) by a considerable margin. The ambient concentration that accompanied 

the next highest total arsenic concentration in bilgewater (32 μg/L from the shrimper) was a 

comparable 29 μg/L, although this moderately high concentration of total arsenic measured in 

the bilgewater sample from the shrimper is likely an overestimate due to positive interference 

(see discussion on page 74). 

The results shown here illustrate that relationships between metals concentrations in 

bilgewater and ambient samples are quite variable, even for the highest concentrations of metals 

measured in bilgewater. EPA acknowledges that such variability could be due to type of 

bilgewater production and dilution onboard. For example, a shrimper might have used a 

substantial amount of ambient water for washdown as compared to a tow boat, and thus, dilute 

what might be a similar actual bilge sample absent the washdown. Clearly the potential for 

metals in bilgewater discharges to pollute receiving waters may be overestimated if the ambient 

metals concentrations and other considerations (type and dilution of bilgewater) are not 

appropriately considered. 

 

In summary, metals were frequently detected in bilgewater samples. EPA found 

relatively high concentrations of a number of dissolved and total metals in these samples. Total 

arsenic and dissolved copper concentrations were significantly elevated above the most 

conservative screening benchmarks in individual samples, with PHQ values from greater than 10 

to over 1,000. Dissolved cadmium concentrations in a single bilgewater sample also generated 

PHQs in this range. For these and other metals (including total aluminum and iron and dissolved 

chromium, lead, nickel, and zinc), concentrations measured in one or several bilgewater samples 

exceeded saltwater and/or freshwater criteria. EPA found that the concentrations of many of the 

metals measured in bilgewater samples (except for dissolved copper and total arsenic) were 

comparable to the ambient receiving water concentrations. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.1.1. Results of Bilgewater Sample Analyses for Dissolved Metals1

Analyte Units No. 

samples 

No. 

detected 

Detected 

Proportion 

(%) 

Average 

Conc. 

Median 

Conc. 

Minimum 

Conc. 

10% 25% 75% 90% 

Heavy and Other Metals 

Aluminum μg/L 7 6 86 150 37 9.7 420 520 Antimony μg/L 5 1 20 0.66 0.65 1.3 Arsenic3 μg/L 7 6 86 41 10 1.1 21 230 Barium μg/L 5 5 100 49 43 38 38 39 62 64 Cadmium μg/L 7 1 14 1.9 10 Chromium μg/L 7 5 71 12 1.6 17 56 Cobalt μg/L 5 2 40 1.0 1.8 2.5 Copper μg/L 7 7 100 100 56 6.6 6.6 25 120 350 Iron μg/L 5 1 20 75 87 170 Lead μg/L 7 3 43 2.3 4.2 7.2 Manganese μg/L 7 7 100 34 28 3.9 3.9 13 50 79 Nickel μg/L 7 6 86 9.2 8.8 4.7 14 15 Selenium4 μg/L 7 4 57 24 30 36 57 Vanadium μg/L 5 1 20 0.62 0.55 1.1 Zinc μg/L 7 7 100 130 100 53 53 72 190 250 

Cationic Metals 

Calcium μg/L 7 7 100 76000 76000 33000 33000 47000 100000 140000 Magnesium μg/L 7 7 100 180000 180000 8300 8300 14000 310000 420000 Potassium μg/L 5 5 100 67000 65000 9800 9800 37000 98000 120000 Sodium μg/L 5 5 100 1400000 1400000 120000 120000 730000 2000000 2700000 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm(3) See footnotes 11 and 12. 

(4) See footnote 13. 

85 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

86 

Table 3.1.2. Results of Bilgewater Sample Analyses for Total Metals1

Analyte Units No. samples No. detected Detected proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 9

Heavy and Other Metals 

Aluminum μg/L 7 7 100 370 330 26 26 28 640 9Antimony μg/L 5 1 20 1.3 0.65 1Arsenic3 μg/L 7 7 100 53 12 1.3 1.3 5.5 32 2Barium μg/L 5 5 100 50 44 38 38 38 66 6Cadmium μg/L 7 1 14 2.6 Chromium μg/L 7 6 86 25 3.5 2 37 Cobalt μg/L 5 1 20 1.3 0.7 1Copper μg/L 7 7 100 150 130 8.5 8.5 50 210 4Iron μg/L 5 3 60 520 250 1100 1Lead μg/L 7 6 86 9.6 7.5 2.3 18 2Manganese μg/L 7 7 100 53 52 7.4 7.4 37 79 9Nickel μg/L 7 6 86 12 9.4 6.2 17 2Selenium4 μg/L 7 4 57 25 25 38 6Vanadium μg/L 5 2 40 2.6 1.4 1Zinc μg/L 7 7 100 160 87 56 56 72 260 3

Cationic Metals 

Calcium μg/L 7 7 100 76000 77000 36000 36000 47000 110000 130Magnesium μg/L 7 7 100 180000 180000 9200 9200 14000 310000 390Potassium μg/L 5 5 100 68000 65000 9600 9600 37000 100000 130Sodium μg/L 5 5 100 1400000 1400000 120000 120000 740000 2000000 260

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm(3) See footnotes 11 and 12. 

(4) See footnote 13.
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

87 

Figure 3.1.1. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Bilgewater 

(Note: As discussed in footnotes 12 and 13, all but possibly one of the bilgewater samples analyzed for dissolved 

selenium and three of the bilgewater samples analyzed for dissolved arsenic may be elevated due to positive 

interference. The measured dissolved arsenic concentration of 230 μg/L for the tow/salvage vessel and measured 

dissolved arsenic concentration of 10 μg/L for the tour boat are not expected to have had positive interference).

Aluminum

Antimony

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Vanadium

Zinc

Dissolved Metals

1

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

88 

Figure 3.1.2. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Bilgewater 

(Note: As discussed in footnotes 11 and 13, all but one of the bilgewater samples analyzed for total selenium and 

three of the bilgewater samples analyzed for total arsenic may be elevated due to probability of positive interference. 

Exceptions are the total arsenic concentration of 291 μg/L for the tow/salvage vessel, concentrations of 19 and 5.5 

μg/L for the tour boat and longliner fishing vessel, respectively, as well as the concentration of 1.3 μg/L for a 

sample of bilgewater from a tow/salvage vessel).

Aluminum

Antimony

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Vanadium

Zinc

Total Metals

1

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100

1000

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

89 

Figure 3.1.3. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals 

in Samples of Bilgewater 

(Note: Values circled here and throughout the rest of this chapter indicate PHQs calculated based on replacement 

values for non-detects. Non-detect (censored) concentrations were replaced with 1⁄2 of the reporting limit for use in 

these plots. Also, as discussed in footnotes 11 and 13, all but one of the bilgewater samples analyzed for total 

selenium and three of the bilgewater samples analyzed for total arsenic may be elevated due to probability of 

positive interference). 

Aluminum

Antimony

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Vanadium

Zinc

Dissolved Metals

0.1

1.0

10.0

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

90 

Figure 3.1.4. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Bilgewater 

(Note: Replacement values for non-detects are circled. Also, as discussed in footnotes 11 and 13, all but one of the 

bilgewater samples analyzed for total selenium and three of the bilgewater samples analyzed for total arsenic may be 

elevated due to probability of positive interference).

Aluminum

Antimony

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Vanadium

Zinc

Total Metals

0.01

0.10

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100.00

1000.00

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.1.2 Classical Pollutants 

Bilgewater samples were analyzed for 14 classical pollutants (see Table 3.1.3). These 

pollutants include measurements that are qualitatively quite different: physical properties (pH, 

temperature, conductivity, salinity, turbidity, TOC, TSS), oxygen consumption (BOD and COD), 

oil and grease (hexane extractable material (HEM) and silica-gel treated hexane extractable 

material (SGT-HEM)), as well as concentrations of several chemicals (sulfide, DO, TOC and 

TRC).17 Figure 3.1.5 illustrates the variability of the concentrations/values measured for the 

classical pollutant in bilgewater. The highest concentrations of BOD, COD and TOC (770, 2970, 

and 732 mg/L, respectively), as well as HEM, SGT-HEM, and TRC, were measured in a single 

bilgewater sample from a tow/salvage boat. BOD and TOC concentrations were highly variable 

among the bilgewater samples, ranging from 2 to 770 mg/L for BOD and from 9 to 730 mg/L for 

TOC. 

Oil and grease were measured as HEM and petroleum hydrocarbons were measured as 

SGT-HEM. HEM and SGT-HEM were detected in all of the bilgewater samples, with 

concentrations ranging from 1.1 to 43.6 mg/L (HEM) and 1.1 to 18.2 mg/L (SGT-HEM). These 

concentrations were compared to the existing international and U.S. regulatory limit of 15 mg/L 

of oil and grease that can be discharged from a moving ship when within 12 nautical miles from 

land18. Some type of oil collector (sorbent pad, rags, etc.) was used on four of the seven vessels 

sampled for bilgewater. A single value taken from the tow/salvage boat exceeded the 15-mg/L 

benchmark by threefold. Oil and grease discharges at this concentration are significant enough to 

cause a visible sheen. The tow/salvage boat had no equipment or management practices in place 

to remove oil or other pollutants prior to overboard discharge of bilgewater. 

 Sulfide was detected in two bilgewater samples, at concentrations of 0.015 and 0.2 mg/L. 

These concentrations exceeded the NRWQC of 2 μg/L (0.002 mg/L) by factors of 7.5 to 100. 

Sulfide (hydrogen sulfide) is a pollutant that is commonly elevated in water distribution systems 

as well as sewers. Sulfur-reducing bacteria, which use sulfur as an energy source, are believed to 

be the primary producers of large quantities of hydrogen sulfide in bilgewater. Ecologically, 

these bacteria are common in anaerobic environments (e.g., plumbing systems). Sulfur-reducing 

bacteria are apparently present in at least some of the vessels, because sulfide was not detected in 

the ambient water sampled at the vessel locations. 

Figure 3.1.6 presents box and dot density plots of the PHQs for classical pollutants. 

PHQs were calculated for the six classical pollutants for which benchmarks were available. As 

this figure shows, all of the detected TRC concentrations exceeded the saltwater chronic 

 

17 See Section 3.1.1 this chapter for the rationale to use this term for this large group of conventional, 

nonconventional, and other physico-chemical factors. 

18 International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 

relating thereto (MARPOL). 

91 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

92 

NRWQC benchmark of 0.0075 mg/L and yielded PHQs ranged from 6.7 to 21. The highest TRC 

concentration (0.16 mg/L) was measured in a bilgewater sample collected from a tour boat. 

EPA compared classical pollutant concentrations in the bilgewater samples to ambient 

concentrations in surface water samples collected near the vessels. Concentrations of a number 

of the classical parameters (including conductivity, pH, salinity, temperature, and (to a varying 

degree) turbidity in bilgewater were comparable with ambient water. This was expected, 

considering the likelihood of ambient water leaking into vessel bilges. The concentration of DO 

measured in one bilgewater sample (1.8 mg/L in the longliner) was hypoxic (<2 mg/L), although 

the ambient DO value at this location (Sitka, Alaska) was also very low (1.0 mg/L). TRC 

concentrations were elevated at 0.1 mg/L in two of the seven bilge samples; for the remaining 

samples, TRC concentrations were comparable between bilgewater and ambient samples. For the 

remaining classical pollutants (BOD, COD, HEM, SGT-HEM, sulfide, TOC, and TSS) the 

concentrations measured in bilgewater greatly exceeded those measured in ambient samples. 

BOD concentrations in three of the bilgewater samples (189, 325, and 770 mg/L) were high 

enough to be comparable to values typical of raw domestic sewage (110 to 400 mg/L; Metcalf 

and Eddy, 1979). These three bilgewater samples also exceed EPA’s secondary treatment 

effluent limit of 30 mg/L for BOD. COD concentrations in four of the bilgewater samples (430, 

546, 780, and 2,970 mg/L) were again high enough to compare with values for raw domestic 

sewage (250 to 1,000 mg/L; Metcalf and Eddy, 1979). These high levels of BOD and COD in 

bilgewater discharges could potentially cause stress on a water body (e.g., where there are many 

sources of oxygen demand, where there may be limited circulation or flushing, or where the 

water body is under existing hypoxic or anoxic stress). Although TSS concentrations in 

bilgewater were not as high as values for raw sewage, four of the bilgewater samples exceeded 

the 30 mg/L effluent limit for TSS by factors ranging from 1.2 to 3. EPA realizes that these 

effluent limits are based upon the high removal efficiencies for BOD and TSS that are achievable 

by land-based sewage treatment plants, and may be overly conservative as benchmarks for vessel 

discharge. However, as discussed in Section 3.1.3, the benchmarks are still useful in a screening 

level analysis as a starting point for evaluating the potential of these pollutants to cause or 

contribute to ecological stress on a water body. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.1.3. Results of Bilgewater Sample Analyses for Classical Pollutants1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90

Biochemical Oxygen Demand (BOD) mg/L 7 7 100 190 14 2.0 2.0 4.1 330 77Chemical Oxygen Demand (COD) mg/L 7 7 100 740 430 91 91 98 780 300Conductivity mS/cm 6 6 100 5.0 6.9 0.017 0.017 0.56 9.3 14 Dissolved Oxygen mg/L 6 6 100 5.3 5.5 1.8 1.8 3.4 6.9 1Hexane Extractable Material (HEM) mg/L 7 7 100 9.3 5.2 1.1 1.1 1.2 7.0 44 pH SU 7 7 100 7.2 7.0 6.9 6.9 6.9 7.3 8.Salinity ppt 6 6 100 5.5 4.5 0.40 0.40 3.1 8.9 13 Silica Gel Treated HEM (SGT-HEM) mg/L 7 7 100 4.4 2.4 1.1 1.1 1.2 3.5 18 Sulfide mg/L 7 2 29 0.034 0.015 0.2Temperature C 7 7 100 20 21 9.0 9.0 14 27 28 Total Organic Carbon (TOC) mg/L 5 5 100 200 110 8.9 8.9 16 440 73Total Residual Chlorine mg/L 7 3 43 0.077 0.13 0.1Total Suspended Solids (TSS) mg/L 7 7 100 39 38 3.7 3.7 5.5 71 88 Turbidity NTU 7 7 100 41 20 3.5 3.5 5.2 41 16Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

93 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

94 

Figure 3.1.5. Box and Dot Density Plot of Classical Pollutant Concentrations 

Measured in Samples of Bilgewater 

1000.00

BOD (mg/l)

COD (mg/l)

Cond (mS/cm)

DO (mg/l)

HEM (mg/l)

SGT-H (mg/l)

Salin. (ppt)Sulf. (mg/l)

TOC (mg/l)

TRC (mg/l)

TSS (mg/l)

Temp. (C)

Turb. (NTU)

pH (SU)

Classical Pollutants

0.01

0.10

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10.00

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

95 

Figure 3.1.6. Box and Dot Density Plot of Potential Hazard Quotients for Classical 

Parameters in Samples of Bilgewater 

(Note: Replacement values for non-detects are circled).

100.00

BOD (mg/l)

COD (mg/l)

Cond (mS/cm)

DO (mg/l)

HEM (mg/l)

SGT-H (mg/l)

Salin. (ppt)Sulf. (mg/l)

TOC (mg/l)

TRC (mg/l)

TSS (mg/l)

Temp. (C)

Turb. (NTU)

pH (SU)

Classical Pollutants

0.10

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

96 

 

3.2.1.3 Pathogen Indicators (Microbiologicals) 

Bilgewater samples19 from two commercial fishing vessels were analyzed for the 

pathogen indicator bacteria E. coli, enterococci, and fecal coliform (commercial fishing vessels 

only) (see Table 3.1.4). E. coli and enterococci were detected in a bilgewater sample collected 

from a shrimping vessel, and fecal coliform were detected in bilgewater from two fishing vessels 

(a longliner and the shrimper). 

The NRWQC for pathogen indicators references the bacteria standards in EPA’s 1986 

Quality Criteria for Water, commonly known as the Gold Book. NRWQC standards for bacteria 

are described in terms of three different water body use criteria: freshwater bathing, marine water

bathing, and shellfish harvesting waters. 

For each of the pathogen indicators, the lowest NRWQC was exceeded in one of the 

bilgewater samples. The E. coli value (393 MPN/100 mL) exceeds the freshwater bathing 

NRWQC of 126 MPN/100 mL. The enterococci value (4,100 MPN/100 mL) exceeds the bathing 

NRWQCs of 33 CFU/100 mL for fresh water and 35 CFU/100 mL for salt water. One of the two 

fecal coliform values (118 CFU/100 mL) exceeds the NRWQC of 14 MPN/100 mL for shellfish 

harvesting20. 

Values of the pathogen indicators measured in these bilgewater samples exceed the 

values measured in nearby ambient surface water samples by factors ranging from 4 (for 

enterococci) to 15 (E. coli), suggesting that leakage or other entry of ambient water is not a 

significant source of these pathogen indicators in bilgewater. EPA is unsure as to the source of 

pathogen indicators in bilgewater. 

19 Logistics prevented EPA from delivering all bilgewater samples to laboratories within allowable holding times. 20 MPN is most probable number and approximates the unit of measure for fecal coliform in this study of CFU 

(colony forming units). 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.1.4. Results of Bilgewater Sample Analyses for Pathogen Indicators1

Analyte Units2 No. Samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

E. Coli MPN/100 ml 1 1 100 390 Enterococci MPN/100 ml 1 1 100 4100 Fecal Coliform CFU/100 ml 2 2 100 61 120 4.0 4.0 4.0 120 120 Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) MPN = Most Probable Number; CFU = Colony Forming Units. (3) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

97 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.1.4 Nutrients 

Bilgewater samples were analyzed for four nutrient-related parameters: ammonia 

nitrogen, nitrate/nitrite, total Kjeldahl nitrogen (TKN), and total phosphorus (see Table 3.1.5). 

The box and dot density plots in Figure 3.1.7 illustrate the variability of the nutrient 

concentrations measured in bilgewater. Ammonia, TKN and total phosphorus concentrations 

were elevated in a single bilgewater sample collected from a longliner fishing vessel. The 

elevated nutrient concentrations may be attributable to seepage from the/ice slurry in the fish 

hold of the longliner. Water containing biological material (e.g., fish waste tissues, excreta) 

might seep down into the bilge compartment, resulting in an increase in nutrient discharge. 

Ammonia is the only nutrient for which there are currently numeric NRWQC. EPA 

established these numeric criteria based on chronic toxicity to aquatic life, not nutrient 

enrichment. An ammonia-nitrogen concentration of 7.6 mg/L, measured in the bilgewater sample 

from the longliner fishing vessel, exceeded the NRWQC chronic criteria in both salt water (1.2 

mg/L) and fresh water (1.24 mg/L). Three of the five bilgewater samples for total phosphorous 

exceeded EPA’s 0.1 mg/L 1986 Gold Book criterion. The highest total phosphorus 

concentration, 13 mg/L, exceeded the benchmark by a factor of 130. Figure 3.1.8 presents box 

and dot density plots of the PHQs calculated for the nutrient data. 

EPA compared nutrient concentrations in the bilgewater samples to ambient 

concentrations in surface water samples collected near the vessels. Ammonia was detected in one 

of the ambient samples at a concentration of 0.11 mg/L, comparable (within a factor of two) to 

the concentration in the corresponding bilgewater sample, 0.13 mg/L. TKN was detected in three 

ambient samples; in one, the ambient concentration of 0.60 mg/L marginally exceeded the 

bilgewater concentration of 0.55 mg/L. However, ambient TKN concentrations were less than 

the bilgewater concentrations in the other two cases. For total phosphorus, the comparison 

showed the concentrations detected in two ambient samples were comparable to the 

corresponding bilgewater concentrations; however, total phosphorus was not detected in the 

ambient samples corresponding to the three bilgewater samples having the highest total 

phosphorus concentrations. Thus, although ambient nutrient concentrations appear to be 

comparable to the lower concentrations of nutrients in bilgewater and may be a partial source of 

these nutrients in some samples, they cannot explain the sources of the higher nutrient 

concentrations measured in other samples. 

98 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.1.5. Results of Bilgewater Sample Analyses for Nutrients1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% Ma

C

Ammonia As Nitrogen (NH3-N) mg/L 5 4 80 1.7 0.24 0.064 4.0 7.6 Nitrate/Nitrite (NO3/NO2-N) mg/L 7 5 71 0.38 0.18 0.36 1.9 Total Kjeldahl Nitrogen (TKN) mg/L 5 5 100 16 2.5 0.55 0.55 1.0 39 73 Total Phosphorus mg/L 5 5 100 3.0 0.47 0.084 0.084 0.093 7.1 13 Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

99 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

NH3-N

NO3/NO2-N

TKN

TP

Nutrients

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Figure 3.1.7. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of 

Bilgewater 

100 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

NH3-N

NO3/NO2-N

TKN

TP

Nutrients

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Figure 3.1.8. Box and Dot Density Plot of Potential Hazard Quotients for Nutrients in 

Samples of Bilgewater 

(Note: Replacement values for non-detects are circled).

101 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

102 

 

3.2.1.5 Semivolatile Organic Compounds (SVOCs) 

Bilgewater samples were analyzed for 79 SVOCs. Out of the 79 analytes, 56 were not 

detected in any of the bilgewater samples. Of the remaining 23 SVOCs, 18 were only detected in 

a single bilgewater sample and five were found in multiple samples (see Table 3.1.6). Of these, 

bis(2-ethylhexyl) phthalate was detected in more than 50 percent of the samples. This SVOC is a 

manufactured chemical that is commonly added to plastics to make them flexible and can be 

found in a variety of products used on vessels such as hoses, tubing, and gaskets. Di-n-butyl 

phthalate, di-n-octyl phthalate, naphthalene, and phenanthrene were also detected in more than 

one bilgewater sample. There was no obvious trend in the occurrence of SVOCs based on the 

type of vessel sampled. 

Figure 3.1.9 presents the range of concentrations measured for SVOCs in the bilgewater 

samples. Concentrations of five SVOCs (2-butoxy ethanol, 2- methyl-naphthalene, dimethyl 

phthalate, indole, and naphthalene) exceeded 100 μg/L in single (but not the same) bilgewater 

samples. It was difficult for EPA to compare the concentration distributions between SVOCs 

because the majority were detected in a single sample. Bis(2-ethylhexyl) phthalate and 

phenanthrene concentrations ranged over nearly two orders of magnitude. 

The distributions of PHQs, based on the most conservative screening benchmarks, are 

displayed for each SVOC in Figure 3.1.10. PHQs for two SVOCs, 2,4,6-trichlorophenol and 

bis(2-ethylhexyl) phthalate, exceeded the screening threshold of one. The 2,4,6-trichlorophenol 

concentration (24 μg/L) measured in a single bilgewater sample from a tour boat exceeded the 

1.4 μg/L human health (water and organism consumption) criterion by a factor of 1721. Bis(2-

ethylhexyl) phthalate was detected in four of the seven bilgewater samples, at concentrations that 

exceeded the 1.2 μg/L human health (water and organism consumption) criterion by factors that 

ranged from 1.1 to 59. As shown in Figure 3.1.10, the PHQs for four other SVOCs were orders 

of magnitude less than 1, and therefore, likely pose little risk as pollutants from bilgewater 

discharges. 

SVOCs were detected in two ambient samples, and for these chemicals (bis(2-ethylhexyl) 

phthalate and Di-n-butyl phthalate) the ambient concentrations were only comparable to the 

lowest concentrations measured in bilgewater. 

21 Because of elevated reporting limits for this SVOC in several samples, replacement values for the nondetected 

concentrations exceed the benchmark (e.g., PHQ >1). However, these values were not based on measured 

concentrations and are therefore uncertain. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.1.6. Results of Bilgewater Sample Analyses for SVOCs1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

2,4,6-Trichlorophenol μg/L 7 1 14 7.0 2-Butoxy ethanol μg/L 1 1 100 260 2-Methylnaphthalene μg/L 5 1 20 39 88 3-Methyl-butanoic acid μg/L 1 1 100 57 4-Methyl-pentanoic acid μg/L 1 1 100 38 Benzeneacetic acid μg/L 1 1 100 29 Benzenepropanoic acid μg/L 1 1 100 32 Benzothiazole μg/L 1 1 100 45 Bis(2-ethylhexyl) phthalate μg/L 7 4 57 15 1.4 21 Cholesterol μg/L 1 1 100 88 Dimethyl phthalate μg/L 7 1 14 24 Di-n-butyl phthalate μg/L 7 2 29 4.0 1.4 Di-n-octyl phthalate μg/L 7 2 29 4.1 3.1 Heptadecane μg/L 1 1 100 56 Indole μg/L 1 1 100 160 Naphthalene μg/L 7 3 43 100 2.3 n-Hexadecane μg/L 1 1 100 39 Nonadecane μg/L 1 1 100 49 p-Cresol μg/L 5 1 20 7.7 8.7 Phenanthrene μg/L 7 2 29 12 1.3 Phenol μg/L 7 1 14 18 Pyrene μg/L 7 1 14 6.8 Triethyl Phosphate μg/L 1 1 100 20 Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

.

103 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

104 

Figure 3.1.9. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Bilgewater 

SVOCs are identified as follows (replacement values for non-detects are circled): 

(1) 2,4,6-Trichlorophenol 

(2) 2-Butoxy Ethanol 

(3) 2-Methylnaphthalene 

(4) 3-Methyl-Butanoic Acid 

(5) 4-Methyl-Pentanoic Acid 

(6) Benzeneacetic Acid 

(7) Benzenepropanoic Acid 

(8) Benzothiazole 

(9) Bis(2-Ethylhexyl) Phthalate 

(10) Cholesterol 

(11) Dimethyl Phthalate 

(12) Di-N-Butyl Phthalate 

(13) Di-N-Octyl Phthalate 

(14) Heptadecane 

(15) Indole 

(16) Naphthalene 

(17) N-Hexadecane 

(18) Nonadecane 

(19) P-Cresol 

(20) Phenanthrene 

(21) Phenol 

(22) Pyrene 

(23) Triethyl Phosphate 

0 2 4 6 8 10 12 14 16 18 20 22 24

SVOCs

1

10

C

o

n

c

e

ntr

atio

n (u

g

/

L) 100
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

105 

Figure 3.1.10. Box and Dot Density Plot of Potential Hazard Quotients for SVOCs in 

Samples of Bilgewater

SVOCs are identified as follows (replacement values for non-detects are circled): 

(1) 2,4,6-Trichlorophenol 

(2) 2-Butoxy Ethanol 

(3) 2-Methylnaphthalene 

(4) 3-Methyl-Butanoic Acid 

(5) 4-Methyl-Pentanoic Acid 

(6) Benzeneacetic Acid 

(7) Benzenepropanoic Acid 

(8) Benzothiazole 

(9) Bis(2-Ethylhexyl) Phthalate 

(10) Cholesterol 

(11) Dimethyl Phthalate 

(12) Di-N-Butyl Phthalate 

(13) Di-N-Octyl Phthalate 

(14) Heptadecane 

(15) Indole 

(16) Naphthalene 

(17) N-Hexadecane 

(18) Nonadecane 

(19) P-Cresol 

(20) Phenanthrene 

(21) Phenol 

(22) Pyrene 

(23) Triethyl Phosphate 

0 2 4 6 8 10 12 14 16 18 20 22 24

SVOCs

0.00001

0.00010

0.00100

0.01000

0.10000

1.00000

10.00000

P

ote

ntial H

a

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ard

Q

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

106 

3.2.1.6 Volatile Organic Compounds (VOCs) 

Bilgewater samples were analyzed for 72 VOCs. Out of the 72 analytes, 46 VOCs were 

not detected in any of the bilgewater samples. Of the remaining 26 VOCs, 11 were detected in 

more than one bilgewater samples and 15 were detected only in one bilgewater sample (see 

Table 3.1.7). Of the 11 VOCs that were detected in more than one bilgewater sample, the 

following were detected in more than 50 percent of the samples: 

 1,2,4-Trimethylbenzene 

 1,3,5-Trimethylbenzene 

 Acetone 

 Benzene 

 m-,p-Xylene (sum of isomers) 

 Methylene chloride 

 O-Xylene. 

2-butanone, ethylbenzene, styrene, and toluene were also detected in more than one 

bilgewater sample. 

Figure 3.1.11 presents the range of concentrations measured for VOCs in the bilgewater 

samples. The VOC concentrations measured in bilgewater samples varied widely, with 

concentrations of a half-dozen VOCs ranging over three orders of magnitude. The maximum 

concentrations of four VOCs (1,2,4-trimethylbenzene, m-,p-xylene, o-xylene and toluene) 

exceeded 1,000 μg/L (1 mg/L), while the maximum concentrations of four other VOCs (1,3,5-

trimethylbenzene, benzene, ethylbenzene and n-propylbenzene) exceeded 100 μg/L. Each of 

these maximum VOC concentrations was measured in the bilgewater sampled from one 

tow/salvage boat. These VOCs are commonly constituents of petroleum products, refining byproducts, and gasoline additives, and are used as solvents. 

Figure 3.1.12 presents the distributions of PHQs for each VOC, based on the most 

conservative screening benchmarks. The maximum PHQ for benzene, based on the 2.2 μg/L 

human health (water plus organism consumption) criterion benchmark, was 187. The maximum 

PHQ for toluene was marginally higher than one; the highest concentration of toluene (1,700 

μg/L) exceeded the human health (water and organism consumption) criterion of 1,300 μg/L. For 

two other VOCs (chloroform and tetrachloroethene), only one of seven sample concentrations 

were detected, and these detected concentrations were below the screening benchmark. However, 

because the method detection limits for these two compounds were more than double their 

respective screening benchmarks, the resulting PHQs for these compounds, as reported in Figure 

3.1.12, are greater than one when concentrations equal to 1⁄2 of the detection limit are included. 

Because these PHQ values were not based on detected concentrations, EPA considers them 

highly uncertain. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

107 

Finally, two VOCs (acetone and methylene chloride) were measured in ambient samples 

at concentrations comparable to the corresponding bilgewater concentration. However, these 

ambient concentrations were only comparable to the lowest concentrations of these VOCs 

measured in some bilgewater samples. Therefore, it is unlikely that leakage or other entry of 

ambient water is a significant source of the elevated acetone and methylene chloride 

concentrations measured in bilgewater. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.1.7. Results of Bilgewater Sample Analyses for VOCs1

Analyte Units No. 

samples 

No. 

detected 

Detected 

Proportion 

(%) 

Average 

Conc. 3

Median 

Conc. 

Minimum 

Conc. 

10% 25% 75% 90% 

1,2,4-Trimethylbenzene μg/L 5 3 60 220 0.50 540 1101,3,5-Trimethylbenzene μg/L 5 3 60 65 0.10 160 320 2-Butanone μg/L 5 2 40 2.6 2.8 3.7 4-Isopropyltoluene μg/L 5 1 20 3.3 3.3 6.5 Acetone μg/L 5 5 100 13 10 2.3 2.3 4.3 23 31 Benzene μg/L 7 4 57 61 0.10 1.3 410 Biphenyl μg/L 5 1 20 4.5 0.87 1.7 Carbon disulfide μg/L 5 1 20 2.0 0.050 0.10 Chloroform μg/L 7 1 14 3.3 4.1 cis-1,2-Dichloroethene μg/L 5 1 20 2.3 0.75 1.5 Cyclohexane μg/L 5 1 20 5.8 9.5 19 Ethylbenzene μg/L 7 3 43 68 1.3 460 Isopropylbenzene μg/L 5 1 20 9.9 20 40 m-,p-Xylene (sum of isomers) μg/L 5 3 60 370 0.50 930 190Methyl tertiary butyl ether (MTBE) μg/L 5 1 20 2.0 0.050 0.10 Methylcyclohexane μg/L 5 1 20 5.4 8.5 17 Methylene chloride μg/L 7 4 57 1.6 0.10 0.20 0.30 Nonanal μg/L 1 1 100 3.1 n-Pentadecane μg/L 1 1 100 58 n-Propylbenzene μg/L 5 1 20 26 60 120 O-Xylene μg/L 5 3 60 240 0.20 590 120Styrene μg/L 5 2 40 11 20 39 Tetrachloroethene μg/L 7 1 14 2.6 0.40 Toluene μg/L 7 3 43 240 0.30 170Trichloroethene μg/L 7 1 14 2.6 0.30 Trichlorofluoromethane μg/L 7 1 14 3.5 5.5 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm(3) In some cases, the detected concentration(s) for an analyte could be lower than the replacement value (1⁄2 of the reporting limit) for a concentration tha

extreme (but possible) case, this could result in an average concentration for an analyte that is greater than the maximum detected concentration. 

108 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

VOCs

0.1

1.0

10.0

100.0

1000.0

C

o

n

c

e

ntr

atio

n (u

g

/

L)

Figure 3.1.11. Box and Dot Density Plot of VOC Concentrations Measured in Samples of 

Bilgewater

VOCs are identified as follows: 

(1) 1,2,4-Trimethylbenzene 

(2) 1,3,5-Trimethylbenzene 

(3) 2-Butanone 

(4) 4-Isopropyltoluene 

(5) Acetone 

(6) Benzene 

(7) Biphenyl 

(8) Carbon Disulfide 

(9) Chloroform 

(10) Cis-1,2-Dichloroethene 

(11) Cyclohexane 

(12) Ethylbenzene 

(13) Isopropylbenzene 

(14) M-,P-Xylene (sum of 

isomers) 

(15) Methyl Tertiary Butyl Ether 

(Mtbe) 

(16) Methylcyclohexane 

(17) Methylene Chloride 

(18) Nonanal 

(19) N-Pentadecane 

(20) N-Propylbenzene 

(21) O-Xylene 

(22) Styrene 

(23) Tetrachloroethene 

(24) Toluene 

(25) Trichloroethene 

(26) Trichlorofluoromethane 

109 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

110 

Figure 3.1.12. Box and Dot Density Plot of Potential Hazard Quotients for VOCs in 

Samples of Bilgewater

VOCs are identified as follows (replacement values for non-detects are circled): 

(1) 1,2,4-Trimethylbenzene 

(2) 1,3,5-Trimethylbenzene 

(3) 2-Butanone 

(4) 4-Isopropyltoluene 

(5) Acetone 

(6) Benzene 

(7) Biphenyl 

(8) Carbon Disulfide 

(9) Chloroform 

(10) Cis-1,2-Dichloroethene 

(11) Cyclohexane 

(12) Ethylbenzene 

(13) Isopropylbenzene 

(14) M-,P-Xylene 

(sum of isomers) 

(15) Methyl Tertiary Butyl Ether 

(Mtbe) 

(16) Methylcyclohexane 

(17) Methylene Chloride 

(18) Nonanal 

(19) N-Pentadecane 

(20) N-Propylbenzene 

(21) O-Xylene 

(22) Styrene 

(23) Tetrachloroethene 

(24) Toluene 

(25) Trichloroethene 

(26) Trichlorofluoromethane 

100.0000

0 2 4 6 8 10 12 14 16 18 20 22 24 26

VOCs

0.0001

0.0010

0.0100

0.1000

1.0000

10.0000

P

ote

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

111 

3.2.1.7 Nonylphenols 

Bilgewater samples were analyzed for 34 long- and short-chain nonylphenol and 

octylphenol ethoxylates (two discrete subsets of alkylphenol ethoxylates), as well as total 

nonylphenol. Of these analytes, 14 alkylphenol ethoxylates were not detected and 20 were 

detected in a single bilgewater sample (see Table 3.1.8). Of the 20 distinct alkylphenol 

ethoxylates detected, 16 were detected in the bilgewater from a tour boat, three were detected in 

the bilgewater from a tow/salvage boat, and one was detected in the bilgewater from a shrimper. 

Measured concentrations of ethoxylates in bilgewater ranged from less than 1 μg/L for three of 

the octylphenol ethoxylate isomers (OP10EO, OP12EO, and OP11EO) to 1,050 μg/L for total 

nonylphenol polyethoxylates (sum of NPEOs – NP5EO through NP18EO). This latter maximum 

concentration was measured in the bilgewater sample from the tour boat. According to the 

operator(s), the bilgewater discharged from this vessel is expected to possibly contain oil, grease, 

fuel, cleaning solvents, detergent and water from deck washdown. Of these pollutants, detergents 

are the most common source of NPEOs. Although there is no NRWQC for the sum of 

alkylphenol ethoxylates, they can degrade to total nonylphenol, which does have a NRWQC, in 

fresh and salt water. 

The one detected concentration for total nonylphenol (NP, representative of the same 

nonylphenol isomers in the commercial mixture upon which EPA’s NRWQC is based – CAS 

#84852-15-3) of 4.9 μg/L exceeded the saltwater chronic criterion of 1.7 μg/L by a factor of 2.9. 

Although the vessel operators added dish soap to the bilgewater prior to overboard discharge, 

this detergent is not necessarily the primary or only source of the detected nonylphenol. 

Lubricants also contain alkylphenol ethoxylates, and oil, grease, and fuel also might accumulate 

in bilgewater. The operators of three of the other vessels where bilgewater was sampled also 

reported using commercial bilge cleaners, yet NP was not detected in samples from those 

vessels. Furthermore, the operator of the tour boat from which 16 of the long- and short-chain 

alkylphenol ethoxylates were detected made no comment about using bilge cleaners. It is 

unlikely that ambient water is the source of NP to bilgewater in the detected sample. 

 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.1.8. Results of Bilgewater Sample Analyses for Nonylphenols1

Analyte Units No. samples No. Detected Detected Proportion (%) Average Conc. 3 Median Conc. Minimum Conc. 10% 25% 75% 

Long-Chain Alkylphenol Ethoxylates 

Total Nonylphenol Polyethoxylates μg/L 5 1 20 260 530 Nonylphenol octodecaethoxylate (NP18EO) μg/L 5 1 20 0.78 1.8 Nonylphenol heptadecaethoxylate (NP17EO) μg/L 5 1 20 1.8 4.2 Nonylphenol hexadecaethoxylate (NP16EO) μg/L 5 1 20 3.6 8.2 Nonylphenol pendecaethoxylate (NP15EO) μg/L 5 1 20 6.8 16 Nonylphenol tetradecaethoxylate (NP14EO) μg/L 5 1 20 12 28 Nonylphenol tridecaethoxylate (NP13EO) μg/L 5 1 20 20 44 Nonylphenol dodecaethoxylate (NP12EO) μg/L 5 1 20 27 61 Nonylphenol undecaethoxylate (NP11EO) μg/L 5 1 20 35 77 Nonylphenol decaethoxylate (NP10EO) μg/L 5 1 20 35 77 Nonylphenol nonaethoxylate (NP9EO) μg/L 5 1 20 33 70 Nonylphenol octaethoxylate (NP8EO) μg/L 5 1 20 28 57 Nonylphenol heptaethoxylate (NP7EO) μg/L 5 1 20 22 42 Nonylphenol hexaethoxylate (NP6EO) μg/L 5 1 20 16 27 Nonylphenol pentaethoxylate (NP5EO) μg/L 5 1 20 9.7 14 Octylphenol dodecaethoxylate (OP12EO) μg/L 5 1 20 0.97 0.25 Octylphenol undecaethoxylate (OP11EO) μg/L 5 1 20 1.4 0.38 Octylphenol decaethoxylate (OP10EO) μg/L 5 1 20 3.2 0.39 

Short-Chain Nonylphenols 

Bisphenol A μg/L 4 1 25 5.3 11 

Nonylphenols 

NP μg/L 4 1 25 9.2 3.7 Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm(3) In some cases, the detected concentration(s) for an analyte could be lower than the replacement value (1⁄2 of the reporting limit) for a concentration tha

extreme (but possible) case, this could result in an average concentration for an analyte that is greater than the maximum detected concentration. 

112 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

113 

3.2.1.8 Summary of the Characterization of Bilgewater Discharge 

Table 3.1.9 summarizes the specific analytes within bilgewater effluent that may have the 

potential to pose risk to human health or the environment for these types of vessels based on 

these samples. EPA’s interpretation of a realized risk likely posed by these analytes, relative to 

pollutant loadings, background ambient and source water contaminant levels and characteristics, 

and other relevant information useful for this assessment, is presented in Chapter 5. 

In summary, among the metals, dissolved copperand zinc were consistently measured at 

concentrations exceeding the most stringent NRWQC in fishing vessels, tow/salvage vessels, 

water taxis, and tour vessels; total arsenic was also measured at concentrations exceeding the 

most stringent NRWQC in a Longliner fishing vessel, a tow/salvage vessel, and tour vessel. The 

classical pollutants BOD, COD, sulfide, TSS, and TRC exceeded the screening benchmarks in at 

least one of the fishing vessels, tow/salvage vessels, water taxis, and tour vessels. Among the 

pathogen indicators, enterococcus, E. coli and fecal coliform bacteria were all present at 

concentrations exceeding NRWQC; these samples were collected only from fishing boats. Total 

phosphorus was the only nutrient to exceed a screening benchmark in bilgewater from all vessel 

types, while ammonia exceeded the screening benchmark in a fishing vessel (longliner). 

Concentrations of the SVOC bis(2-ethylhexyl) phthalate exceeded NRWQC in the bilgewater 

discharges of fishing vessels, tow/salvage vessels, water taxis, and tour vessels, while 2,4,6-

trichlorophenol exceeded the screening benchmark in only the tour vessel. Benzene and toluene 

sampled from tow/salvage vessels were the only VOCs found at concentrations exceeding the 

most stringent NRWQC. The screening benchmark for total nonylphenol was exceeded in a 

single sample collected from a fishing vessel. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.1.9. Characterization of Bilgewater Discharge and Summary of Analytes that May Have the Poten

Analytes that May Have the Potential to Pose Risk in Bilgewater Discharge and V

Vessel Type (no. vessels)

Microbiologicals 

Volatile Organic Compounds 

Semivolatile Organic Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Sulfide 

Short-Chain Alkylphenol 

Ethoxylates and NP 

Long-Chain Alkylphenol 

Ethoxylatess 

Fishing (2) enterococcus, 

E. coli, 

Fecal Coliform

Cu, Zn As x x 

Tow/Salvage (2) Benzene, 

Toluene 

Bis(2-ethylhexyl)-

phthalate 

Cu, Zn As x x 

Water Taxis (2) Bis(2-ethylhexyl)- 

phthalate 

Cu, Zn As 

Tour (1) Bis(2-ethylhexyl)-

phthalate, 

2,4,6-Trichlorophenol 

Cu, Cd, Zn As x 

(1) Analytes are generally bolded when a large proportion of the samples have concentrations exceeding the NRWQC (e.g., 25 to 50 percent), when sev

PHQs > 10 (e.g., two or three of five), when a few samples result in PHQs greatly exceeding the screening benchmark (i.e., 100s to 1,000s), or, in the cas

nonylphenol, when one or more samples exceed an existing regulatory limit by more than a factor of 2. See text in Section 3.1.3 for a definition of PHQs a

benchmarks used to calculate these values. (2) EPA notes that the conclusion of potential risk is drawn from a small sample size, in some cases a single vessel, for certain discharges sampled from 

included these results in the tables to provide a concise summary of the data collected in the study, but strongly cautions the reader that these conclusionsamples from a given vessel class, should be considered preliminary and might not necessarily represent pollutant concentrations from these discharges class.

114 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.2 Stern Tube Packing Gland Effluent 

The packing gland or stuffing box surrounds the propeller shaft at the point it exits a 

boat's hull underwater. Based on the vessels sampled for this analysis, using a packing gland is a 

common method for preventing water from entering the hull while still allowing the propeller 

shaft to turn. A stuffing box packed with greased flax rings is designed to leak a few drops per 

minute of ambient water to cool the gland when a vessel is underway. Stuffing boxes are also 

used to seal rudder stocks that penetrate the hull below the waterline. The packing gland effluent 

water is often collected in a segregated section of the bilge that generally contains an automatic 

bilge pump. 

During this study, EPA observed this segregated discharge onboard tugboats but not on 

any other vessel classes. In most of the other vessels sampled, the packing gland effluent dripped 

directly into the bilge. Possible constituents of concern in the packing gland effluent include 

metals (from contact of the discharge with the drive shaft), hydraulic fluid, grease or lubricants 

found in the gland, and fuel constituents since the packing gland is located in the engine 

compartment. 

Based on field observations from EPA’s vessel sampling program, EPA estimated the 

drip rate into the stuffing box at approximately 10 drips per minute, which is consistent with the 

literature data (Casey, 2007; Chin, 2005). This equates to a stern tube effluent generation rate of 

between 2 and 4 gpd. Since most tugboats had dual propeller systems, these boats are expected to 

generate between 4 and 8 gpd of stern tube effluent. 

For this study, EPA collected samples from the packing gland effluent from nine 

tugboats. Samples on these vessels were analyzed for metals (dissolved and total), classical 

pollutants, nutrients, VOCs, SVOCs, and nonylphenols. Packing gland effluent samples were 

collected by placing a glass transfer jar under the shaft to collect any water dripping and then 

compositing the sample in a Teflon-lined pail. In some cases, EPA dipped the transfer jar into the 

segregated bilge compartment. If the vessels had a dual propeller system, EPA collected samples 

from each for the composite. However, samples for analysis of oil and grease and VOCs are not 

appropriate to composite, so these samples were collected separately. 

3.2.2.1 Metals 

Packing gland effluent samples were analyzed for both total and dissolved concentrations 

of 22 metals. Of the 22 metals, 18 total metals and 15 dissolved metals were detected in the EPA 

sample set (see Table 3.2.1). Antimony, beryllium, silver, and cadmium were not detected in any 

samples in the total or dissolved form, while cobalt, iron, thallium, and vanadium were not 

detected in the dissolved form. Figures 3.2.1 and 3.2.2 present box and dot density plots of the 

detected results for dissolved and total metals, respectively. The box and density plots in Figures 

115 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.3 and 3.2.4 present these same detected results for dissolved and total metals, respectively, 

normalized by the lowest NRWQC where applicable. Points on these plots above the dashed line 

(demarking a PHQ of 1) indicate metals concentrations exceeding the benchmark. With a few 

exceptions, the metal concentrations normalized by the lowest NRWQC were below the PHQ of 

1. 

Dissolved and total aluminum were found in all nine samples analyzed. Dissolved 

aluminum was detected at concentrations ranging from 7.8 to 150 μg/L in the packing gland 

effluent; however, no screening benchmark is available for dissolved aluminum. Total aluminum 

was detected at concentrations ranging from 50.7 to 6,400 μg/L and exceeded the screening 

benchmark of 87 μg/L eight times. Arsenic, both total and dissolved, was detected in three of 

nine samples in the packing gland effluent, although the sample with the highest measured total 

and dissolved arsenic concentrations may be elevated resulting from positive interference (see 

discussion in Section 3.1.3). All three total arsenic values exceeded the screening benchmark of 

0.018 μg/L (based on the human health criterion for drinking water plus fish consumption) with 

values of 2.8, 4.4, and 15.3 μg/L. None of the three detected dissolved arsenic values (1.2, 1.4 

and 14.7 μg/L) exceeded the screening benchmark of 36 μg/L (based on the saltwater chronic 

criterion for the protection of aquatic life). Dissolved copper was detected in four of nine 

samples with values ranging from16.2 to 92 μg/L. All four sample values exceeded the screening 

benchmark of 3.1 μg/L. Total copper was detected in seven of the nine samples from the packing 

gland effluent, with values ranging from 7 to 891 μg/L. None of the total copper values exceeded 

the screening benchmark of 1,300 μg/L. 

Dissolved and total nickel was detected in six of nine and eight of nine packing gland 

effluent samples respectively. Two of the total nickel results (1,670 and 3,230 μg/L) exceeded 

the screening benchmark of 610 μg/L, while all of the dissolved nickel values exceeded the 

screening benchmark of 8.2 μg/L. Zinc was found in seven of nine samples in the dissolved form 

and eight of nine samples in the total form. One sample value of 120 μg/L for dissolved zinc 

exceeded the screening benchmark of 81 μg/L. Selenium was found in three of nine samples in 

the dissolved form and only one of nine samples in the total form (the latter an exceptionally 

high concentration of 42.1 μg/L suspected of reflecting positive interference). Dissolved 

chromium and lead were also detected in several samples. Chromium values exceeded the 

benchmark criteria of 11 μg/L in four detected samples. Dissolved lead was detected at a 

concentration of 4.9 μg/L, which slightly exceeded the benchmark of 2.5 μg/L. 

Total iron, manganese, and thallium were all detected at levels below the screening 

benchmarks, except for one sample for total thallium that was detected at the reporting level of 1 

μg/L. This sample exceeded the benchmark of 0.24 μg/L for thallium and has a PHQ of 4.17 as 

shown on Figure 3.2.4. Barium, sodium, and potassium, in both forms (total and dissolved) were 

detected in three of three samples, but did not exceed benchmark criteria. The metals magnesium 

and calcium, in both forms (total and dissolved); cobalt and vanadium (in total); and dissolved 

116 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

117 

manganese were detected in one or more samples but no screening criteria exists for these 

compounds. 

EPA analyzed ambient metal concentrations to determine if dissolved and total aluminum 

concentrations found in packing gland effluent were contributed primarily by the vessel or 

reflected contributions primarily by background ambient concentrations. For both dissolved and 

total aluminum, sample concentrations were moderately influenced by ambient background 

concentrations, with ambient concentrations as high as 130 μg/L (dissolved aluminum) and 3,950 

μg/L (total aluminum). For both dissolved and total arsenic, sample concentrations from stern 

tube packing gland effluent were strongly influenced by ambient background concentrations. 

Ambient dissolved and total arsenic concentrations as high as 16.1 and 15.4 μg/L, respectively, 

were measured in water surrounding one of the three vessels sampled (a vessel sampled in 

Baltimore, Maryland), although these measured concentrations may be elevated due to positive 

interference. Ambient background concentrations of both dissolved and total copper were 

comparatively low relative to the packing gland effluent sample concentrations and therefore of 

little influence (i.e., dissolved and total copper concentrations were largely from packing gland 

effluent). As in the case of copper, nickel was not found at high levels in the surrounding 

ambient water; thus, nickel is another metal that may have a significant source from the packing 

gland effluent. All of the selenium values were consistent with concentrations in the surrounding 

water. Neither chromium nor lead was strongly influenced by ambient concentrations in the 

surrounding water. The concentrations barium, sodium, potassium, magnesium, calcium cobalt, 

vanadium, and manganese generally reflect the concentrations in the surrounding water. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

118 

Table 3.2.1. Results of Packing Gland Effluent Sample Analyses for Metals1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Heavy and Other Metals 

Aluminum, Dissolved4 μg/L 9 9 100 88 110 7.8 7.8 31 140 150 Aluminum, Total4 μg/L 9 9 100 1200 300 51 51 170 1500 6400 Arsenic, Dissolved3 μg/L 9 3 33 3.3 1.3 15 Arsenic, Total3 μg/L 9 3 33 3.8 3.6 15 Barium, Dissolved3 μg/L 3 3 100 53 63 30 30 30 66 66 Barium, Total3 μg/L 3 3 100 88 98 32 32 32 140 140 Chromium, Dissolved μg/L 9 5 56 19 3.8 20 110 Chromium, Total μg/L 9 8 89 230 130 9.7 440 760 Cobalt, Total4 μg/L 3 2 67 3.0 2.9 5.6 5.6 Copper, Dissolved μg/L 9 4 44 22 38 92 Copper, Total μg/L 9 7 78 140 20 3.5 150 890 Iron, Total4 μg/L 3 3 100 3900 2700 710 710 710 8300 8300 Lead, Dissolved4 μg/L 9 1 11 1.8 4.9 Lead, Total μg/L 9 3 33 7.9 8.9 43 Manganese, Dissolved4 μg/L 9 8 89 44 9.6 2.9 53 250 Manganese, Total4 μg/L 9 9 100 160 110 79 79 93 230 350 Nickel, Dissolved μg/L 9 6 67 210 13 370 1000 Nickel, Total μg/L 9 8 89 610 45 12 970 3200 Selenium, Dissolved3 μg/L 9 3 33 8.1 1.2 41 Selenium, Total3 μg/L 9 1 11 8.6 42 Thallium, Total4 μg/L 3 1 33 0.67 1.0 1.0 Vanadium,Total3 μg/L 3 1 33 4.6 13 13 Zinc, Dissolved4 μg/L 9 7 78 34 18 3.3 53 120 Zinc, Total μg/L 9 8 89 70 73 11 120 180 

Cationic Metals 

Calcium, Dissolved3 μg/L 9 9 100 36000 24000 23000 23000 23000 35000 11000Calcium, Total3 μg/L 9 9 100 37000 24000 22000 22000 23000 39000 11000
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

119 

Table 3.2.1. Results of Packing Gland Effluent Sample Analyses for Metals1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Magnesium, Dissolved3 μg/L 9 9 100 40000 7800 6200 6200 6500 11000 29000Magnesium, Total3 μg/L 9 9 100 39000 7900 6000 6000 6300 12000 28000Potassium, Dissolved3 μg/L 3 3 100 39000 4700 4000 4000 4000 110000 11000Potassium, Total3 μg/L 3 3 100 37000 4600 4600 4600 4600 100000 10000Sodium, Dissolved3 μg/L 3 3 100 810000 20000 18000 18000 18000 2400000 240000Sodium,Total3 μg/L 3 3 100 810000 20000 17000 17000 17000 2400000 240000

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm(3) Sample concentrations are strongly influenced by background concentrations in ambient water, accounting for greater than 90% of sample concentrat

samples. (4) Sample concentrations are moderately influenced by background concentrations in ambient water, accounting for between 50 and 90% of sample consamples. (5) Maximum concentrations may be elevated as a result of positive interference. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

120 

Figure 3.2.1. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Packing Gland Effluent 

(Note: Maximum concentrations of arsenic and selenium may be elevated as a result of positive interference).

Aluminum

Arsenic

Barium

Chromium

Copper

Lead

Manganese

Nickel

Selenium

Zinc

Dissolved Metals

1

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1000

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

121 

Figure 3.2.2. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Packing Gland Effluent 

(Note: Maximum concentrations of arsenic and selenium may be elevated as a result of positive interference).

Aluminum

Arsenic

Barium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Thallium

Vanadium

Zinc

Total Metals

1

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

122 

Figure 3.2.3. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals 

in Samples of Packing Gland Effluent 

(Note: Replacement values for non-detects are circled. Also, maximum concentrations of arsenic and selenium may 

be elevated as a result of positive interference.)

Aluminum

Arsenic

Barium

Chromium

Copper

Lead

Manganese

Nickel

Selenium

Zinc

Dissolved Metals

0.1

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

123 

Figure 3.2.4. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Packing Gland Effluent 

(Note: Replacement values for non-detects are circled. Also, maximum concentrations of arsenic and selenium may 

be elevated as a result of positive interference).

100.000

Aluminum

Arsenic

Barium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Thallium

Vanadium

Zinc

Total Metals

0.001

0.010

0.100

1.000

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

124 

3.2.2.2 Classical Pollutants 

EPA sampled the packing gland effluent for numerous classical pollutants to further 

characterize this discharge type for the tugboats sampled under this program. The classical 

pollutants include measurements that are physical properties (temperature, conductivity, salinity, 

turbidity, TSS), oxygen consumption (BOD, COD), oil and grease (HEM and SGT-HEM), as 

well as chemical concentrations (pH, sulfide, DO, and TRC). Table 3.2.2 presents the data for 

these parameters. 

Figure 3.2.5 illustrates the varied concentrations of measured for these parameters in the 

packing gland effluent. Most of the concentrations and values reported reflect the concentrations 

and values in the ambient water surrounding the vessel, as this water is the source of the drive 

shaft water. Two parameters (sulfide and TRC) were not detected in any samples. 

The PHQs were calculated for the classical pollutants for which they were available. 

Only two pollutants exceeded these PHQ screening benchmarks (see Figure 3.2.6): oil and 

grease and TSS. One of the vessel samples had values which exceeded the screening benchmark 

for oil and grease measured as both HEM and petroleum hydrocarbon (SGT-HEM). The 

concentrations detected were 66.7 mg/L for HEM and 55.8 mg/L for SGT-HEM, both of which 

exceeded the benchmark of 15 mg/L. EPA noted a visible oily sheen on the surface of this 

effluent and evidence of settled hydrocarbons on the bottom of the tank as this sample was 

collected. Based upon conversations with the vessel engineer, the likely source is an oil leak that 

was somehow making its way into this effluent. This seems a plausible explanation given that 

background concentrations of HEM and SGT-HEM in surrounding ambient water were very low 

(< 1.5 mg/L) relative to the measured sample concentrations. 

Total suspended solids were detected in all nine samples collected from the packing 

gland effluent. Two samples with concentrations of 269 and 134 mg/L exceeded the screening 

benchmark of 98 mg/L.
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.2.2. Results of Packing Gland Effluent Sample Analyses for Classical Pollutants1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Conductivity mS/cm 9 9 100 1.6 0.30 0.22 0.22 0.22 0.55 Dissolved Oxygen mg/L 9 9 100 8.3 8.4 5.3 5.3 7.2 9.3 Total Organic Carbon (TOC) mg/L 7 7 100 3.5 3.5 2.2 2.2 2.6 4.8 Biochemical Oxygen Demand (BOD) mg/l 9 9 100 11 7.2 3.3 3.3 4.3 13 Chemical Oxygen Demand (COD) mg/l 9 4 44 31 53 Hexane Extractable Material (HEM) mg/l 9 5 56 14 1.65 23 pH SU 9 9 100 7.1 7.5 2.4 2.4 7.3 8.0 Salinity ppt 8 7 88 0.14 0.20 0.10 0.20 Silica Gel Treated HEM (SGT-HEM) mg/l 9 5 56 13 1.7 19 Temperature C 9 9 100 20 20 9.3 9.3 18 23 Total Suspended Solids (TSS) mg/l 9 9 100 59 28 5.6 5.6 13 81 Turbidity NTU 9 9 100 46 18 9.0 9.0 13 70 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

125 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

BOD

COD

Conductivity

DO

HEM

SGT-HEM

Salinity

TOC

TSS

Temperature

Turbidity

pH

Parameter

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of Packing Gland Effluent

126 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

BOD

COD

Conductivity

DO

HEM

SGT-HEM

Salinity

TOC

TSS

Temperature

Turbidity

pH

Parameter

2

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Figure 3.2.6. Box and Dot Density Plot of Potential Hazard Quotients for Classical 

Pollutants in Samples of Packing Gland Effluent 

(Note: Replacement values for non-detects are circled).

127 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

128 

3.2.2.3 Nutrients 

Packing gland effluent samples were analyzed for four nutrient-related parameters: 

ammonia nitrogen, nitrate/nitrite, TKN, and total phosphorus (see Table 3.2.3). Figures 3.2.7 and 

3.2.8 illustrate the variability of the nutrients in the packing gland effluent. Ammonia, 

nitrate/nitrite, and TKN were detected in most of the samples analyzed, but in relatively low 

concentrations. Phosphorus was detected in seven of the nine tugboat samples collected. 

Only ammonia has a current numeric NRWQC value. The results for ammonia detected 

in the packing gland effluent range from 0.07 to 0.23 mg/L, well below the benchmark of 1.2 

mg/L. TKN and nitrate/nitrite were detected in all of the nine tugboat samples, with values 

ranging from 0.40 to 1.8 mg/L for TKN to 0.62 to 1.5 mg/L for nitrate/nitrite. Total phosphorus 

was detected in seven of the nine samples for packing gland effluent. The detected 

concentrations ranged from 0.06 to 0.25 mg/L and only two values, 0.19 and 0.25 mg/L, exceed 

the 0.1 mg/L benchmark. 

Most of these values for ammonia, TKN, and nitrate/nitrite are consistent with ambient 

background results in each location. The background ambient for these total phosphorus samples 

reported values from 0.06 to 0.19 mg/L, indicating a moderate influence of surrounding ambient 

water on sample concentrations. 

In general, it appears that nutrient concentrations from packing gland effluent are 

generally low and the wastestream does not appear to be adding significant nutrients to the 

surrounding waters. Nutrient addition from packing gland effluent was not considered a likely 

concern in this discharge relative to metals from contact of the discharge with the drive shaft, 

hydraulic fluid, grease or lubricants from the gland, and fuel constituents. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.2.3. Results of Packing Gland Effluent Sample Analyses for Nutrients1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Ammonia As Nitrogen (NH3-N) mg/L 9 7 78 0.10 0.10 0.034 0.14 0.23 Nitrate/Nitrite (NO3/NO2-N) mg/L 9 9 100 0.69 0.62 0.085 0.085 0.58 0.80 1.5 Total Kjeldahl Nitrogen (TKN) mg/L 9 9 100 1.1 1.4 0.41 0.41 0.69 1.4 1.8 Total Phosphorus mg/L 9 7 78 0.13 0.10 0.030 0.22 0.25 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

129 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

NH3-N

NO3/NO2-N

TKN

Total P

Nutrients

0.4

0.8

1.2

1.6

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Figure 3.2.7. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of 

Packing Gland Effluent 

130 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

NH3-N

NO3/NO2-N

TKN

Total P

Nutrients

0.5

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2.0

2.5

3.0

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Figure 3.2.8. Box and Dot Density Plot of Potential Hazard Quotients for Nutrients in 

Packing Gland Effluent

131 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

132 

 

3.2.2.4 Volatile and Semivolatile Organic Chemicals 

 Packing gland effluent samples were analyzed for 70 VOCs and 73 SVOCs in nine 

tugboats (see Table 3.2.4). Of the analytes tested, six VOC compounds and 10 SVOC 

compounds were detected in the samples. Figures 3.2.9 and 3.2.10 illustrate the range of 

concentrations measured for SVOCs and VOCs, respectively. 

 Three VOCs, m-p-xylene, acetone, and methylene chloride, were detected in more than 

one sample. Eight of the 10 SVOCs detected were found in one sample. Bis(2-ethylhexyl) 

phthalate was found in the effluent of three vessels sampled and n-hexadecane was found in the 

effluent of two of the vessels sampled. Bis(2-ethylhexyl) phthalate was detected at notably high 

(compared to ambient surrounding water) values of 2.8, 5.4, and 23.5 μg/L. The only other 

compound with a screening benchmark is di-n-butyl phthalate, which was detected in one sample 

with a concentration of 2.45 μg/L, which is well below the screening benchmark of 2,000 μg/L. 

These two phthalate compounds are used as plasticizers, and bis(2-ethylhexyl) phthalate is used 

as a hydraulic fluid and as a dielectric fluid in capacitors. 

 Figure 3.2.12 presents the distributions of PHQs, based on the most conservative 

screening benchmarks, for each VOC; none of the detected values exceed the screening 

threshold22 . PQH was above one for all three samples of bis(2-ethylhexyl) phthalate, based on 

the screening benchmark of 1.2 μg/L (Figure 3.2.11). 

Of the six VOC and 10 SVOC compounds detected in packing gland effluent samples, 

bis(2-ethylhexyl) phthalate was the only compound whose measured concentrations in the 

discharge was substantially higher than in ambient water; all other VOCs and SVOCs detected in 

packing gland effluent appear to reflect the similar concentrations found in surrounding water. 

22 PHQs for benzene, methylene chloride and tetrachloroethene in multiple packing gland effluent samples were 

based on replacement values of 1⁄2 of the reporting limit for nondetected concentrations. In Figure 3.2.12 the PHQs 

based on replacement values for nondetected concentrations have been circled for identification. EPA does not 

consider PHQs that exceed 1 to signal that these discharges pose a potential risk to cause or contribute to the nonattainment of a water quality standard when the PHQs are based on replacement values for nondetected 

concentrations. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.2.4. Results of Packing Gland Water Sample Analyses for SVOCs and VOCs1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. 3 Median Conc. Minimum Conc. 10% 25% 75

SVOCs 

2,6,10,14-Tetramethyl Pentadecane μg/L 1 1 100 12 3,6-Dimethylundecane μg/L 1 1 100 8.7 5-Butyl-Hexadecane μg/L 1 1 100 6.7 Bis(2-ethylhexyl) phthalate μg/L 9 3 33 4.7 4Di-n-butyl phthalate μg/L 9 1 11 1.7 Dodecane μg/L 1 1 100 5.0 Eicosane μg/L 1 1 100 5.4 n-Hexadecane μg/L 2 2 100 5.5 6.0 5.0 5.0 5.0 6Nonanoic Acid μg/L 1 1 100 4.3 

VOCs 

Acetone μg/L 3 3 100 2.9 2.7 2.7 2.7 2.7 3Benzene μg/L 9 1 11 1.4 m-,p-Xylene (sum of isomers) μg/L 3 2 67 1.7 0.10 0.Methylene chloride μg/L 9 2 22 1.2 0.n-Pentadecane μg/L 1 1 100 11 Sulfur dioxide μg/L 1 1 100 13 Tetrachloroethene μg/L 9 1 11 1.4 Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm(3) In some cases, the detected concentration(s) for an analyte could be lower than the replacement value (1⁄2 of the reporting limit) for a concentration tha

extreme (but possible) case, this could result in an average concentration for an analyte that is greater than the maximum detected concentration. 

133 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

0 1 2 3 4 5 6 7 8 9 10

SVOCs

5

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Figure 3.2.9. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Packing Gland Effluent Samples

SVOCs are identified as follows: 

(1) 2,6,10,14-Tetramethyl Pentadecane 

(2) 3,6-Dimethylundecane 

(3) 5-Butyl-Hexadecane 

(4) Bis(2-ethylhexyl) phthalate 

(5) Di-n-butyl phthalate 

(6) Dodecane 

(7) Eicosane 

(8) n-Hexadecane 

(9) Nonanoic acid 

134 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

0 1 2 3 4 5 6 7 8

VOCs

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Figure 3.2.10. Box and Dot Density Plot of VOC Concentrations Measured in Samples of 

Packing Gland Effluent Samples

VOCs are identified as follows: 

(1) Acetone 

(2) Benzene 

(3) m-,p-Xylene (sum of isomers) 

(4) Methylene chloride 

(5) n-Pentadecane 

(6) Sulfur dioxide 

(7) Tetrachloroethene

135 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

0 1 2 3 4 5 6 7 8 9 10

SVOCs

0.001

0.010

0.100

1.000

10.000

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Figure 3.2.11. Box and Dot Density Plot of Potential Hazard Quotients for SVOCs in 

Samples of Packing Gland Effluent

SVOCs are identified as follows (replacement values for non-detects are circled): 

(1) 2,6,10,14-Tetramethyl Pentadecane 

(2) 3,6-Dimethylundecane 

(3) 5-Butyl-Hexadecane 

(4) Bis(2-ethylhexyl) phthalate 

(5) Di-n-butyl phthalate 

(6) Dodecane 

(7) Eicosane 

(8) n-Hexadecane 

(9) Nonanoic Acid 

136 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

137 

Figure 3.2.12. Box and Dot Density Plot of Potential Hazard Quotients for VOCs in 

Samples of Shaft Packing Gland Effluent

VOCs are identified as follows (replacement values for non-detects are circled): 

(1) Acetone 

(2) Benzene 

(3) m-,p-Xylene (sum of isomers) 

(4) Methylene chloride 

(5) n-Pentadecane 

(6) Sulfur dioxide 

(7) Tetrachloroethene 

0 1 2 3 4 5 6 7 8

VOCs

1

2

3

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.2.5 Nonylphenols 

EPA analyzed samples of shaft packing gland effluent for long and short chain 

nonylphenol and octylphenol ethoxylates and NP because of the possibility of alkylphenolcontaining water from the bilge or other areas of the vessel leaking into the shaft packing gland 

effluent compartment. Table 3.2.5 presents the detected results. 

Of the nine samples for which long- and short-chain nonylphenol and octylphenol 

ethoxylates were analyzed, only six long-chain isomers of the octylphenol polyethoxylate 

(OPEO) type were detected: OP12EO, OP11EO, OP10EO, OP9EO, OP8EO, and OP7EO. All of 

the detected OPEOs are long-chain octylphenols and were found in one tugboat sampled. The 

OPEO with the longest ethoxylate chain (OP12EO) was detected at the lowest concentration 

(Figure 3.2.13). The OPEO isomers showed the trend of increasing concentrations as the size of 

the ethoxylate chain is reduced (from OP12EO to OP7EO), indicating moderately advanced 

degradation of the long-chain OPEOs in the packing gland. 

Average concentrations of OPEOs with the longest ethoxylate chains (OP12EO through 

OP10EO) were similar to bilgewater effluent (see Table 3.1.8). In contrast to bilgewater effluent, 

however, NP was not detected in packing gland effluent. 

None of the OPEOs detected in the packing gland effluent sample were detected in 

ambient water, indicating a probable source from onboard the vessel (tugboat) – possibly from 

seepage from the bilge. Another possible source of OPEOs in packing gland effluent could be 

from the use of lubricants for which octylphenol ethoxylates are common constituents. 

 

138 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.2.5. Results of Packing Gland Water Sample Analyses for Nonylphenols1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 

Octylphenol dodecaethoxylate (OP12EO) μg/L 9 1 11 1.7 Octylphenol undecaethoxylate (OP11EO) μg/L 9 1 11 2.6 Octylphenol decaethoxylate (OP10EO) μg/L 9 1 11 4.8 Octylphenol nonaethoxylate (OP9EO) μg/L 9 1 11 5.3 Octylphenol octaethoxylate (OP8EO) μg/L 9 1 11 10 Octylphenol heptaethoxylate (OP7EO) μg/L 9 1 11 13 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

139 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

140 

Figure 3.2.13. Box and Dot Density Plot of Nonylphenol Concentrations Measured in 

Samples of Packing Gland Effluent 

OP10EOOP11EOOP12EO

OP7EOOP8EOOP9EO

Nonylphenols

10

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30

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

141 

3.2.2.6 Summary of the Characterization of Packing Gland Discharge 

Table 3.2.6 summarizes the specific analytes within packing gland effluent that may have 

the potential to pose risk to human health or the environment for these types of vessels based 

upon these samples. EPA’s interpretation of a realized risk likely posed by these analytes, 

relative to pollutant loadings, background ambient and source water contaminant levels and 

characteristics, and other relevant information useful for this assessment, is presented in Chapter 

5. 

To summarize the results of packing gland discharge measured in the nine tugboats, 

metals were the constituents found most frequently and with the highest magnitudes of 

exceedance of their respective screening benchmarks. Among the dissolved forms of metals, 

concentrations of copper, chromiumand nickel exceeded the most stringent NRWQC 

benchmarks. Among the total forms of metals, aluminum, arsenic, iron, manganese and nickel 

exceeded the most stringent NRWQC benchmarks. However, concentrations of total iron and 

total manganese in surrounding (ambient) waters were similar to concentrations measured in 

packing gland discharge. Among the classical pollutants, most of the concentrations and values 

reported reflect the concentrations and values in the ambient water surrounding the vessel, as this 

water is the source of the drive shaft water. Exceptions were two samples for oil and grease 

(HEM and SGT-HEM) values which exceeded screening benchmarks. Two (of nine) total 

phosphorus samples also exceeded the screening benchmark; however, these concentrations were 

similar to total phosphorus concentrations in the surrounding waters. Among the remaining 

contaminants, the SVOC bis(2-ethylhexyl) phthalate had a PHQ of >10 for one of the vessels 

sampled, and six of the relatively long-chained octylphenols were measured in one of the nine 

vessels sampled. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.2.6. Characterization of Packing Gland Effluent and Summary of Analytes that May Have the Pot

Analytes that May Have the Potential to Pose Risk in Packing Gland and Ves

Vessel Type (no. vessels)

Microbiologicals 

Volatile Organic Compounds 

Semivolatile Organic Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Sulfide 

Short-Chain Alkylphenol 

Ethoxylates and NP 

Long-Chain Alkylphenol 

Tugboats (9) Bis(2-ethylhexyl)- 

phthalate 

Cu, Cr, Ni Al, As, Ni x x 

(1) Analytes are generally bolded when a large proportion of the samples have concentrations exceeding the NRWQC (e.g., 25 to 50 percent), when sev

two or three of five), when a few samples result in PHQs greatly exceeding the screening benchmark (i.e., 100s to 1,000s), in the case of oil and grease asamples exceed an existing regulatory limit by more than a factor of 2, or when concentrations of analytes are sufficiently high that they may have the pot

See text in Section 3.1.3 for a definition of PHQs and Table 3.1 for screening benchmarks used to calculate these values. 

142 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.3 Deck Washdown 

Deck washdowns involve removing dirt, grit, or other materials that can impact the 

integrity of the deck surface (for aesthetic and safety reasons) and are a common vessel 

maintenance task. The process uses hoses and/or swabs (mops) to move the deck washdown 

water, debris, and cleaning agents (if any) to the scuppers, which then discharge the water 

overboard. EPA collected samples of deck water as it is drained through the scupper against the 

hull of the vessel (see Section 2.2.4 Sampling Methods). More than half the vessels sampled 

reported using detergents (dish soaps, ZEPTM, Simple GreenTM) or other cleaners (chlorine 

bleach) during the washdown process. Depending on the vessel's design and function, deck 

washdown water sometimes contains contaminants such as detergents, metals, oil, particulates, 

and pathogens (the latter primarily from catch brought onboard fishing vessels). 

Deck washdowns can occur at any time onboard these classes of vessels. Fishing vessels 

most often discharge while underway either into the nearshore (< 3 Nm from shore) or farshore 

(> 3 Nm from shore). Washdowns are usually performed on fishing vessels after nets are pulled, 

fish are brought onboard and cleaned, while returning to port, and after offloading the catch. 

EPA notes that the majority of deck washdown samples from fishing vessels were taken while 

the vessel was shoreside, and do not reflect constituents of deck washdown while the vessel is 

engaged in fishing operations. Decks are washed less frequently for other types of vessels such 

as water taxis, tour boats, and tow boats. Wash locations are generally pierside after excursions 

or within the harbor for these types of vessels. 

The volume of deck washdown water generated by a vessel depends on the frequency of 

deck washdown, the flow rate from the hose, and the washdown time. Since most vessels use a 

common garden-hose for deck washdowns, EPA estimated the flow rate to be between 10 and 12 

gallons per minute (gpm). The time required for deck washdown varies depending on the type of 

vessel and size. EPA observed during the vessel sampling program that most deck washdowns 

were generally 15 minutes or less. 

Vessels such as tour boats, water taxis, and tow boats would generate an average 

deckwash water volume between 20 and 30 gpd during the peak summer season, assuming their 

decks are washed once every week. Deckwash water volume for fishing boats varies depending 

on the type of boat. For example, trollers, trawlers, gill netters, and purse seiners sometimes 

wash their decks three to four times per day while fishing, plus one additional time after 

unloading seafood at the processing facility. For these vessels, deckwash volumes might range 

between 750 and 900 gpd. 

 

143 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Collecting Deck Washdown Samples from a Tow and Salvage Vessel 

Deck Washdown Sample Collected in a Lined Bucket 

144 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

For this study, EPA collected deck washdown samples from 32 vessels: 11 fishing 

vessels (gillnetter, trawlers, and trollers), nine tugboats, six tow/salvage vessels, two tour boats, a 

water taxi, a fire boat, a supply boat, and a recreational boat (see Table 2-1). EPA collected 

single grab samples from one or more scuppers (composited sample if more than one accessible 

scupper) on selected vessels for laboratory analysis in order to determine representative pollutant 

concentrations for deck washdown across the range of normal vessel operations. 

 EPA also sampled a deck runoff discharge during a rain event. Deck runoff differs from 

washdown in that the runoff discharge occurs because of precipitation or spray landing on the 

deck in sufficient quantities to mobilize pollutants on the deck surface rather than an intentional 

introduction of washdown water (often including detergents). However, deck runoff incorporates 

pollutants that would have been included in an eventual washdown so the samples are 

comparable. The deck runoff sample was collected from a fishing trawler that was being 

unloaded at a fish processing facility in the Northeastern United States. 

EPA focused its sampling effort on the following analyte groups in deck 

washdown/runoff that were expected to be present in the discharge: metals, classical pollutants, 

pathogen indicators (commercial fishing vessels only), nutrients, nonylphenols, and semivolatile 

and volatile organic compounds (tow/salvage vessels only). Results for each class of pollutant 

are presented and discussed in the subsections below. 

3.2.3.1 Metals 

Deck washdown water samples were analyzed for dissolved and total metals. The 

analytical results are summarized in Table 3.3.1. The following metals were detected in 90 

percent or more of the deck washdown water samples: 

 Dissolved and total aluminum 

 Dissolved and total barium 

 Total chromium 

 Total cobalt 

 Dissolved and total copper 

 Total iron 

 Total lead 

 Dissolved and total manganese 

 Dissolved and total zinc. 

Concentrations of a number of other metals were detected in 50 percent or more of the 

samples analyzed: 

 Total antimony 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

 Dissolved and total arsenic23 24

 Dissolved chromium 

 Dissolved cobalt 

 Dissolved iron 

 Dissolved and total nickel 

 Dissolved selenium25

 Dissolved and total vanadium. 

Figure 3.3.1 presents the concentration ranges for dissolved metals detected in the 

samples. These plots show that dissolved metals concentrations span three orders of magnitude. 

Aside from the alkali and alkali earth metals that are the major cations in seawater (Na, K, Ca, 

Mg), average dissolved concentrations of iron, aluminum, and zinc were highest, followed by 

dissolved barium, manganese, and copper. Concentrations of total metals are displayed in Figure 

3.3.2, and follow the same general pattern, but are much higher than their corresponding 

dissolved metal concentrations (fds substantially <1.0), except for Na, K, Ca, and Mg, which 

exist almost entirely in their dissolved forms (see Table 3.3.1). 

For all metals, the mean ratios of dissolved to total metal concentrations (fds) in a 

particular sample range from a low of 0.11 for aluminum to 0.89 for selenium (Table 3.3.2). The 

fds for the 13 (out of 14) metals for which corresponding data are available are approximately 

equal to or less than 50 percent, indicating that at least half of the total metal concentration in 

deck washdown water samples is in particulate form. Such results were expected from certain 

vessels (e.g., tugboats and supply boats) where particulate material was readily visible on deck 

surfaces. Particulate metal is less biologically available than dissolved metals, and therefore less 

likely to cause an immediate toxic effect in aquatic organisms. 

Dissolved cadmium concentrations were detected in two of the 31 vessels sampled - a 

supply and tow/salvage boat. The concentrations were 1.2 (supply boat) and 22.4 μg/L 

(tow/salvage boat), which exceeded the saltwater chronic aquatic life criterion (8.8 μg/L) in the 

case of the tow/salvage boat and the freshwater chronic aquatic life criterion (0.25 μg/L) in both 

cases. 

 

23 Even though a dissolved metal is detected in 50% of the samples, it does not mean that the total metal value 

(which includes dissolved and particulate metals) is considered to be detected in the laboratory analyses. All 

dissolved metal detections are not considered total metal detections because the detection limits differ for a given 

sample based on dissolved versus total recoverable metal analyses. For example, in the case of selenium, the 

detection limit for total recoverable selenium was 5 μg/L for the analysis. In contrast, the detection limit for 

dissolved selenium in these analyses was as low as 1 μg/L. 24 EPA suspects that in a very limited number of deck wash samples (deck wash samples from two shrimping 

vessels), measured concentrations of dissolved and total arsenic may be elevated due to positive interference from 

major seawater cations. 

25 EPA suspects that in a limited number of deck wash samples (i.e., deck wash samples from two shrimping vessels 

and two tow/salvage vessels), measured concentrations of dissolved and total selenium may be elevated due to 

positive interference from major seawater cations. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Deck washdown water samples collected from 29 of the 31 vessels sampled contained 

dissolved copper concentrations that exceeded the saltwater chronic aquatic life criterion of 3.1 

μg/L. Dissolved copper concentrations ranged from 2.5 μg/L for a tug and fishing (trawler) boat 

to 204 μg/L for the supply boat. The dissolved copper concentrations in deck washdown samples 

from the tug and assorted fishing boats were evenly distributed across the entire range of 

measured dissolved copper concentrations, while the tow/salvage, fire, taxi, tour, and supply 

boats all had relatively high dissolved copper concentrations (above 30 μg/L). 

Dissolved lead concentrations exceeding the freshwater chronic aquatic life criterion (2.5 

μg/L) were limited to just three (of nine) tugboats, five (of six) tow/salvage boats, one of the two 

tour boats, and the fire and supply boats. Dissolved lead concentrations exceeding chronic 

aquatic life criterion concentrations ranged from 2.9 μg/L for one of the tugboats to 53.5 μg/L 

for the supply boat. 

Similar to dissolved copper, dissolved zinc in deck washdown samples collected from the 

majority of vessels sampled (22 of 31) exceeded the most stringent 2006 NRWQC - the saltwater 

chronic aquatic life criterion of 81 μg/L. In contrast to dissolved copper, however, only the deck 

washdown samples from the various types of fishing boats appeared to be evenly distributed 

throughout the entire measured dissolved zinc concentration range, while dissolved zinc in deck 

washdown water samples collected from all the tugboats exceeded the criterion. Dissolved zinc 

concentrations in deck washdown water samples ranged from 16 μg/L for a fishing vessel (the 

gillnetter) to 1,200 μg/L for one of the tugboats. All but one of the tow/salvage boats produced 

dissolved zinc in deck washdown water samples exceeding the criterion, as did the tour, fire, and 

supply boats (the last with a measured dissolved zinc concentration of 465 μg/L). 

For the other dissolved metals (chromium, nickel, and selenium) where measured 

concentrations exceeded the saltwater and/or freshwater criteria in one or more of the deck 

washdown water samples, the PHQs were generally less than two (most likely less than one for 

dissolved selenium after considering there may be elevated measured concentrations as a result 

of positive interference for the four samples with measured dissolved selenium concentrations 

exceeding 5 μg/L). For both chromium and nickel, the tow/salvage vessel type had the greatest 

number of dissolved metal concentration exceedances for their respective most stringent criteria. 

No information was available concerning the frequency of deck washdowns for the supply 

vessel, although this particular vessel is known to transport petroleum products, and its deck 

appeared visibly “soiled” to the samplers. According to the surveys, the tow/salvage boats 

generally undergo deck washdowns once to twice per week, about the same frequency as 

tugboats, but less frequent than the fishing and tour boats. 

Four of the total metals (aluminum, arsenic, iron, and manganese) exceeded the most 

stringent 2006 NRWQC in approximately half (manganese) or all the deck washdown water 

samples (aluminum, arsenic, and iron), although sample concentrations of these metals appear to 

147 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

be greatly influenced by surrounding ambient water concentrations (see Table 3.3.3). This 

pattern was identical to the one observed for bilgewater discharge. In contrast to the bilgewater 

samples, about half the deck washdown water samples for a fifth metal (antimony) exceeded the 

most stringent 2006 NRWQC in the deck washdown water samples, as shown in Figure 3.3.4. 

PHQs for total arsenic ranged from 56 to 4,600. All of the total arsenic concentrations exceeded 

the most stringent human health (water plus organism consumption) criterion of 0.018 μg/L, as 

well as the human health criterion for organism consumption alone, 0.14 μg/L. The protective 

human health criteria values for total arsenic are driven by the carcinogenic potential of this 

metalloid. However, when compared to the less stringent saltwater chronic aquatic life criterion 

for arsenic of 36 μg/L, only five of the 31 vessels produced total arsenic concentrations in deck 

washdown water samples that exceeded this less stringent criterion, and the corresponding PHQs 

ranged only from 1.0 to 2.3. These total arsenic exceedances were found on a shrimping vessel 

(positive interference may have elevated the measured concentration, see footnote 24), three (of 

the six) tow/salvage vessels, and the fire boat. In fact, the total arsenic concentrations in deck 

washdown water samples from all six of the tow/salvage boats were close to or within the upper 

quartile of samples. 

Figure 3.3.3 displays the distribution of PHQs based on the most conservative (most 

protective) screening benchmark for each of the dissolved metals. PHQs for four of the dissolved 

metals (cadmium, copper, lead, and zinc) include values from greater than 10 to over 100, 

indicating that the measured concentrations were one or more orders of magnitude greater than 

the most conservative screening benchmark. In addition, although the mean dissolved selenium 

PHQ was less than one, there were two measured occurrences where PHQ exceeded 10, 

however, the high measured concentration of dissolved selenium in these two samples are likely 

due to positive interference, see footnote 25). PHQs exceeding one were also observed for 

dissolved chromium and nickel, bringing to seven the number of dissolved metals that exceeded 

the most stringent 2006 NRWQC in one or more deck washdown water samples. 

PHQs for total aluminum were also high, ranging from 7.5 to 150, followed closely by 

total iron, with PHQs ranging from 3.1 to 48. For both metals, the majority of tug and 

tow/salvage boats were consistently above the median (middle concentration of the range) of 

total metal concentrations (in addition to the fire and supply boats), while the fishing boats were 

below the respective median total metal concentrations. Conversely, only three of the PHQs for 

total manganese exceeded a value of 5 (a tugboat, the supply boat, and the water taxi). 

The frequency of PHQ exceedances for antimony, like total arsenic, are driven by the low 

human health (water plus organism consumption) criterion of 5.6 μg/L (the human health 

criterion for organism consumption alone (640 μg/L) is much higher). Only five of the 19 vessels 

from which deck washdown water samples were obtained had PHQ below 1, and were collected 

from the supply, fire, recreational, and two of the salvage vessels. Among the PQHs for 

antimony that were greater than 1, the low PHQ of 5.2 corresponded with the supply boat, and 

148 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

the high PHQ of 47 corresponded with a tow/salvage vessel – a PHQ value three times higher 

than in the recreational vessel (PHQ = 15). 

From the perspective of potential risk, the discharges of metals where dissolved and total 

concentrations exceed EPA’s most stringent criteria correlate most strongly to utility, passenger, 

or general service vessels such as the supply boat, tow/salvage boats, tugboats, water taxi, and 

fire boat. Commercial fishing vessels may not be a source of concern except for metals such as 

dissolved copper. 

EPA tested the hypothesis that the utility, service, and passenger vessels (referred to as 

nonfishing vessels) discharged metals at higher concentrations than fishing vessels per discharge 

event using two approaches. For both approaches, 20 nonfishing vessels (the tow/salvage boats, 

tugboats, tour vessels, fire boat, water taxi, and supply vessels) were compared to the 10 fishing 

vessels (six shrimping vessels, two trawlers, one troller, and a gillnetter). For the analysis, when 

multiple minimum detection limits were reported for a particular metal, the minimum 

concentration was set to 1⁄2 of the highest reporting limit. This more conservative approach was 

chosen to reduce the likelihood of detecting a difference that was not a “true” difference (Type I 

error). 

For the first approach, a subset of the metals with the highest frequencies of screening 

benchmark (NRWQC) exceedance from the nonfishing vessels were compared to those from the 

fishing vessels. Although there is no NRWQC for total lead, this metal was used in these 

analyses because of the high proportion of nondetects in the dissolved form. This analysis was 

performed using modified t-tests for unequal sample sizes and uneven variances (see Table 

3.3.4). Concentrations of dissolved zinc and total lead were significantly higher in deck 

washdown discharges of non-fishing vessels (e.g., tug boats) than fishing vessels. Although 

concentrations of total arsenic were not significantly different between nonfishing and fishing 

vessels, when the six tow/salvage vessels were compared to the remaining 24 vessels, total 

arsenic concentrations in the tow/salvage vessels were significantly higher than in other vessels 

(Table 3.3.4). When this analysis was performed for dissolved lead despite the occurrence of 

nondetects, the results were the same (i.e., concentrations of dissolved lead in industrial vessels 

were higher than in fishing vessels). 

For the second approach, mean concentrations for both dissolved and total forms of the 

heavy metals (cadmium, chromium, copper, lead, nickel, zinc) were compared using an exact 

binomial test. This approach assumes that, even if the difference in mean concentrations between 

nonfishing and fishing vessels for any given metal is not statistically significant, if the mean 

metal concentrations from a particular vessel class are always or nearly always lower than those 

of another class of vessels, then the overall trend may be statistically significant. Both dissolved 

and total metals concentrations of all six heavy metals were higher in nonfishing vessel 

discharges than in fishing vessel discharges (see Table 3.3.5). A binomial test was then 

149 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

performed to determine whether the overall pattern of lower mean metal concentrations in 

fishing vessel discharges could be attributed to chance, assuming an equal likelihood that 

concentrations in fishing vessels or industrial vessels would be lower. The probability that mean 

concentrations of all six metals (either dissolved or total) would be lower in fishing vessels 

compared to nonfishing vessels, given an equal likelihood of either outcome occurring, was 

statistically significant (P = 0.016). The probability of concentrations being lower in fishing 

vessels for all 12 comparisons (six dissolved metals + six total metals) was also statistically 

significant (P = 0.0002). The mean concentrations of these heavy metals by vessel class are 

shown in Table3.3.5. Results of this analysis support the assertion that metals from deck 

washdown discharges from nonfishing (utility, service, and passenger) vessels tend to be higher 

than metals from deck washdown discharges from fishing vessels for each discharge event. 

One possible explanation for the higher metal concentrations in nonfishing vessels is that 

the frequent washing of fishing vessels’ decks may prevent metal build-up and keep metal 

concentrations lower in each individual deck washdown discharge. 

With regard to assessing potential risk, it is important to understand that, for most of the 

metals identified above as of potential concern in deck washdown water, maximum metal 

concentrations in the ambient or potable water used for deck washdown (see left two thirds of 

Table 3.3.3) were higher than the median metal concentrations in deck washdown water samples 

(Table 3.3.1). The ambient receiving waters to which these deck washdown waters are being 

discharged have metal concentrations that often exceed the most stringent NRWQC (see far right 

column of Table 3.3.3). The relatively high metals concentrations for four dissolved metals 

(copper, manganese, nickel, zinc) in potable water and four total metals (aluminum, arsenic, iron, 

lead) in ambient water can at least partially account for the high concentrations of metals found 

in some of the deck wash discharges. Furthermore, based on corresponding concentrations of the 

major seawater cations (calcium, magnesium, sodium, and potassium) in the deck washdown 

water samples (see Table 3.3.1), few, if any, of the potentially toxic dissolved metal 

concentrations are likely to be bioavailable to biological organisms because of the high hardness 

values, which reduce metal bioavailability. 

In summary, metals were frequently detected in deck washdown water samples, with 

certain metals occurring much more frequently at levels that may have potential for risk than 

others. EPA found high concentrations of a number of dissolved and total metals in these 

samples. Dissolved cadmium, copper, lead, nickel and zinc were consistently elevated above the 

most conservative screening benchmarks, with all the PHQ values in the 1 to 100 range. 

However, dissolved cadmium concentrations measured in deck washdown water samples were 

only detected in two of 31 vessels. For these and other metals (total aluminum, arsenic, iron, and 

manganese), concentrations measured in most if not all of the water samples exceeded saltwater 

and/or freshwater criteria, however they generally did not exceed concentrations in the ambient 

150 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

151 

or potable water used for washdown, and would generally not be bioavailable to organisms in 

seawater. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.3.1. Results of Deck Washdown/Runoff Sample Analyses for Metals1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Heavy and Other Metals 

Aluminum, Dissolved μg/L 31 28 90 420 260 1.7 31 570 11Aluminum, Total μg/L 31 30 97 3400 1900 820 990 4700 83Antimony, Dissolved μg/L 19 9 47 7.3 4.2 Antimony, Total μg/L 19 13 68 26 1.9 29 Arsenic, Dissolved3 μg/L 31 19 61 6.4 2.3 9.8 Arsenic, Total3 μg/L 31 23 74 18 8.3 29 Barium, Dissolved μg/L 19 19 100 63 42 23 27 33 69 Barium, Total μg/L 19 19 100 270 100 52 59 70 160 13Cadmium, Dissolved μg/L 31 2 6 1.3 Cadmium, Total μg/L 31 5 16 2.0 1Chromium, Dissolved μg/L 31 17 55 5.1 2.3 9.1 Chromium, Total μg/L 31 29 94 34 24 3.1 8.3 55 Cobalt, Dissolved μg/L 19 12 63 2.7 1.3 3.9 8Cobalt, Total μg/L 19 18 95 6.0 4.1 1.1 2.0 6.7 Copper, Dissolved μg/L 31 29 94 42 23 5.6 7.2 59 1Copper, Total μg/L 31 31 100 130 110 6.4 12 47 160 3Iron, Dissolved μg/L 19 12 63 520 190 1100 11Iron, Total μg/L 19 18 95 4400 2300 950 1700 5300 130Lead, Dissolved μg/L 31 15 48 6.0 4.7 Lead, Total μg/L 31 30 97 48 23 3.6 8.0 42 1Manganese, Dissolved μg/L 31 29 94 60 35 2.7 11 91 2Manganese, Total μg/L 31 28 90 210 98 4.3 55 300 5Nickel, Dissolved μg/L 31 19 61 6.9 4.8 8.2 Nickel, Total μg/L 31 25 81 16 12 6.2 18 Selenium, Dissolved4 μg/L 31 17 55 8.9 1.1 2.1 Selenium, Total4 μg/L 31 12 39 9.5 1.8 Thallium, Dissolved μg/L 19 1 5 0.64 Vanadium, Dissolved μg/L 19 14 74 1.9 1.3 2.0 5Vanadium,Total μg/L 19 16 84 9.8 6.2 2.9 9.8 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human 

153 

Table 3.3.1. Results of Deck Washdown/Runoff Sample Analyses for Metals1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Zinc, Dissolved μg/L 31 31 100 260 120 16 35 51 430 6Zinc, Total μg/L 31 31 100 580 330 20 52 150 720 14

Cationic Metals

Calcium, Dissolved μg/L 31 31 100 73000 34000 5900 25000 32000 83000 1900Calcium, Total μg/L 31 31 100 77000 39000 7300 27000 34000 88000 1900Magnesium, Dissolved μg/L 31 31 100 130000 14000 6600 7000 7900 59000 5100Magnesium, Total μg/L 31 31 100 130000 19000 6800 7800 9200 59000 5100Potassium, Dissolved μg/L 19 19 100 30000 8000 3300 4000 5400 24000 1400Potassium, Total μg/L 19 19 100 30000 8100 3600 3900 5600 25000 1300Sodium, Dissolved μg/L 19 19 100 510000 79000 26000 38000 45000 410000 28000Sodium,Total μg/L 19 19 100 510000 78000 24000 38100 45000 400000 26000

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of e

least that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. 

(2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

(3) See footnote 24. 

(4) See footnote 25. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Table 3.3.2. Dissolved-to-Total Metal Ratios (fds) in Paired Deck Washdown/Runoff 

Samples 

Summary Statistics of Dissolved:Total 

Metal Metal Ratios Calculated for Select Metals

Geomean Median Min Max 

Aluminum 0.10 0.12 0.010 1.00 

Iron 0.12 0.090 0.050 0.33 

Lead 0.14 0.18 0.030 0.62 

Chromium 0.16 0.13 0.060 0.76 

Vanadium 0.25 0.26 0.12 1.13 

Manganese 0.25 0.28 0.010 0.93 

Antimony 0.30 0.34 0.14 0.64 

Copper 0.33 0.34 0.050 1.04 

Arsenic 0.38 0.47 0.060 0.93 

Cadmium 0.48 0.49 0.36 0.62 

Nickel 0.50 0.53 0.17 0.93 

Cobalt 0.53 0.52 0.26 1.25 

Zinc 0.54 0.54 0.18 2.95 

Selenium 0.89 0.89 0.61 1.30 

Table 3.3.3. Minimum and Maximum Dissolved and Total Metal Concentrations in Vessel 

Source1 and Ambient2 (Harbor) Water Relative to Median Sample Concentrations and 

Most Stringent Screening Benchmarks 

Metal 

Source 

Water 

Conc. 

(min) 

Source 

Water 

Conc. 

(max) 

N 

Median 

Conc. 

From 

Table 

3.3.1 

Ambient

Conc. 

(min) 

Ambient 

Conc. 

(max) 

N 

Most 

Stringent 

Screening

BM 

Aluminum, Dissolved 6.3 310 6 258 0 870 12 NA 

Aluminum, Total 8.6 250 6 1900 44.5 3950 15 87 

Arsenic, Dissolved 0 1.9 3 2.3 2 26 8 36 

Arsenic, Total 0 1.8 3 8.3 2.9 28.9 8 0.018 

Copper, Dissolved 2.4 36 5 23.1 0 24.2 10 3.1 

Copper, Total 2.6 51 4 109 0 23.3 11 1300 

Iron, Dissolved 0 0 1 189.5 226 259 2 NA 

Iron, Total 0 801 4 2330 114 4180 8 300 

Lead, Total 1.2 6 2 23 0 3.1 3 2.5** 

Manganese, 

Dissolved 0 33 6 34.8 0 106 11 NA 

Manganese, Total 3.6 37 6 97.8 8.3 165 13 100 

Nickel, Dissolved 0 3 4 4.8 2.3 7.2 10 8.2 

Nickel, Total 0 2.7 4 12 2.4 16.7 11 610 

Selenium, Dissolved 0 1.6 3 1.1 1.7 75.53 8 5 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Table 3.3.3. Minimum and Maximum Dissolved and Total Metal Concentrations in Vessel 

Source1

 and Ambient2 (Harbor) Water Relative to Median Sample Concentrations and 

Most Stringent Screening Benchmarks 

Metal 

Source 

Water 

Conc. 

(min) 

Source 

Water 

Conc. 

(max) 

Median Most 

N 

Conc. Ambient Ambient Stringent From 

Table 

3.3.1 

Conc. 

(min) 

Conc. N Screening (max) BM 

Selenium, Total 0 1.9 2 0 19.43 86.53 6 170 

Zinc, Dissolved 4.1 1200 6 124 0 116 13 81 

Zinc, Total 4.1 1100 6 331 0 23.9 15 7400 

N = sample size. 

(1) Ambient water was collected from background water surrounding the vessel sampled. 

(2) Source water was collected from the city tap water supply while pierside, except for one tugboat in 

Havre De Grace, Maryland, where source water was collected from a potable water storage tank on 

the vessel (service water) that was filled with city water. 

(3) As discussed in footnote 25, EPA suspects positive interference may have resulted in these high 

measured concentrations of total and dissolved selenium detected in ambient deck wash samples. 

Table 3.3.4. Comparison of Metal Concentrations in Deck Washdown Discharge Between 

Fishing Vessels and Non-Fishing Vessels1

Average Metal Concentration (μg/L) by Welch’s Modified 

Metal Form Vessel Type 2-Sample t-Test 

Fishing Non-Fishing t df P<|tα/2| 

Copper Dissolved 27.7 50.7 -1.68 18.2 0.110 

Nickel Dissolved 6.19 7.23 -1.05 20.7 0.306 

Zinc Dissolved 161 314 -2.15 14.9 0.049 

Arsenic2 Total 14.0 20.5 -0.49 19.8 0.629 

Lead Total 5.48 70.7 -3.76 19.1 0.001 

Notes: 

(1) Nonfishing vessels defined as tow/salvage vessels, tugboats, tour vessels, fire boat, water taxis, and 

supply vessels. The recreational vessel is not a study vessel and was excluded from these analyses. 

(2) Total arsenic concentrations discharged from the six tow/salvage boats were significantly higher than 

for the other 24 vessels (Welch’s Modified 2-Sample t-test, t=-5.26, P<0.001, on 16.7 df). 

155 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Table 3.3.5. Mean Concentrations of Dissolved and Total Heavy Metals from Deck Wash 

Discharges from Fishing Vessels and Nonfishing Vessels1,2 

Conc. (μg/L) in Conc. (μg/L) in 

Metal Form Fishing 

Vessels 

n Not Det. 

(%) 

Non-Fishing 

Vessels 

n Not Det. 

(%) 

Cadmium Dissolved 0.750 10 100 1.86 20 90 

Chromium Dissolved 3.79 10 70 5.93 20 35 

Copper Dissolved 27.7 10 0 50.7 20 0 

Lead Dissolved 2.00 10 100 8.85 20 45 

Nickel Dissolved 6.19 10 40 7.23 20 40 

Zinc Dissolved 161 10 0 314 20 0 

Cadmium Total 2.00 10 100 3.77 20 90 

Chromium Total 15.7 10 20 42.3 20 0 

Copper Total 93.2 10 0 157 20 0 

Lead Total 5.48 10 10 70.7 20 0 

Nickel Total 8.65 10 40 19.4 20 10 

Zinc Total 207 10 0 791 20 0 

Notes: 

(1) Nonfishing vessels defined as tow/salvage vessels, tugboats, tour vessels, fire boat, water taxis, and 

supply vessels. The recreational vessel is not a study vessel and was excluded from these analyses. 

(2) For these comparisons, minimum concentrations were set at 1⁄2 of the reporting limit of the highest 

minimum detection level, when multiple detection limits were present. Average concentrations of 

dissolved and total forms of all six heavy metals were lower in fishing vessels than in nonfishing vessels. 

156 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

157 

Figure 3.3.1. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Deck Washdown Water 

(Note: As discussed in footnotes 24 and 25, EPA suspects positive interfence may have resulted in elevated 

measured concentrations for a limited number of deck wash samples analyzed for dissolved arsenic and dissolved 

selenium). 

Aluminum

Antimony

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Thallium

Vanadium

Zinc

Dissolved Metals

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

158 

Figure 3.3.2. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Deck Washdown Water 

(Note: As discussed in footnotes 24 and 25, EPA suspects positive interfence may have resulted in elevated 

measured concentrations for a limited number of deck wash samples analyzed for total arsenic and dissolved 

selenium). 

Aluminum

Antimony

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Vanadium

Zinc

Total Metals

1

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

159 

Figure 3.3.3. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals 

in Samples of Deck Washdown Water 

(Note: Replacement values for non-detects are circled. Also, as discussed in footnotes 24 and 25, EPA suspects 

positive interfence may have resulted in elevated measured concentrations for a limited number of deck wash 

samples analyzed for dissolved arsenic and dissolved selenium). 

Aluminum

Antimony

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Thallium

Vanadium

Zinc

Dissolved Metals

0.1

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Aluminum

Antimony

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Vanadium

Zinc

Total Metals

0.01

0.10

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Samples of Deck Washdown Water 

(Note: Replacement values for non-detects are circled. Also, as discussed in footnotes 24 and 25, EPA suspects 

positive interfence may have resulted in elevated measured concentrations for a limited number of deck wash 

samples analyzed for total arsenic and dissolved selenium). 

160 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.3.2 Classical Pollutants 

Deck washdown water samples from 32 vessels were analyzed for 14 classical pollutants 

(see Table 3.3.6). The classical pollutants include measurements that are physical properties 

(temperature, conductivity, salinity, turbidity, TSS), oxygen consumption (BOD, COD), oil and 

grease (HEM and SGT-HEM), as well as chemical concentrations (pH, sulfide, DO, and TRC). 

Measured values of the physical properties of the discharge (conductivity, dissolved 

oxygen, pH, temperature, salinity) are unremarkable and appear to reflect conditions at the time 

(seasonality) and location (geographical) of sampling. For instance, conductivity and salinity in 

deck washdown water appear to reflect the type of source water used (ambient or potable 

service/city26 water), as shown by the measured values of these two parameters. Half the fishing 

vessels appear to have used ambient saltwater during normal operations (six of 11 vessels), while 

the remaining fishing boats and nearly all other vessel types (tugs, tow/salvage, tour, supply 

boats) used a freshwater source (aboard the vessel or pierside). Levels of pH were generally 

about neutral (between 7 and 8), with the only exceptions being two tugboats where the pH was 

9.1 and 9.8 (relatively high). Temperature of the deck washdown water ranged from 7.5 to 32 o

C 

and varied according to month (season) sampled and geographic location (warmer water samples 

in southern United States and colder in mid-Atlantic and northern states). Dissolved oxygen 

(DO) in deck washdown samples was sufficiently saturated (50 percent plus; DO ranged from 

5.5 to 10.5 mg/L) in all samples, except for low DO concentrations from three fishing vessels 

participating in the north Pacific fishery, which ranged from 1.6 to 1.9 mg/L. 

Figure 3.3.5 illustrates the variability of the values measured for the classical pollutants 

in deck washdown water. Turbidity (measure of water clarity) and TSS are clearly related and 

range from 4.1 to 460 NTU and 31 to 530 mg/L, respectively. Measured values above the 

median concentrations were dominated by the tug, tow/salvage, supply, fire, and water taxi boats 

for both parameters, while measured values below the median were largely from the fishing 

boats (with only a few exceptions). EPA notes that the majority of deck washdown samples from 

fishing vessels were taken while the vessel was shoreside, and do not reflect constituents of deck 

washdown while the vessel is engaged in fishing operations. Potable water measured during the 

study was low in turbidity (0 to 16 NTU) and TSS (0 mg/L), as was ambient (harbor) water, 

except for waters sampled in the Gulf Coast (Louisiana). Ambient turbidity and TSS were as 

high as 186 NTU and 98 mg/L, respectively, in a sample collected from one harbor in Louisiana. 

Of the remaining parameters, BOD, COD, and TOC have quite high concentrations (see 

Figure 3.3.5). While the measured values for these parameters in deck washdown water samples 

were generally evenly distributed for the different vessel types across the entire concentration 

 

26 Service water here means the vessel potable water supply. For study vessels, vessel service water generally 

originates from municipal water supply rather than produced on board. When deck washdown is performed pierside 

most vessels used city water as their source water. Many fishing vessels and at least one tugboat use ambient water 

as their water source when performing deck washdown offshore or underway. 

161 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

range, a select few vessels were clear standouts: three tugboats, a fishing (shrimping) vessel, and 

the supply boat. The concentrations of all three parameters were highly variable and span two 

orders of magnitude. In contrast, measured sulfide concentrations from deck washdown water 

samples collected from two fishing boats and a tow/salvage boat were all relatively low, but, 

when compared to the most stringent NRWQC of 0.002 mg/L, had PHQs ranging from 2.5 to 8.5 

(moderate exceedance - data not shown). 

PHQs were calculated for three additional classical pollutants for which benchmarks 

were available and are shown in Figure 3.3.6. As the figure shows, the TRC concentrations 

where TRC was detected above the reporting limit of 0.10 mg/L greatly exceeded the benchmark 

(most stringent NRWQC of 0.0075 mg/L, the saltwater chronic aquatic life criterion) by factors 

that ranged from 23 (tow/salvage vessel) to 106 (exceedance by 2 orders of magnitude – a 

fishing vessel). These concentrations (ranging from 0.17 to 0.80 mg/L) were measured in deck 

washdown water samples collected from three (of the 11) fishing vessels, the two tour boats, a 

tugboat, and the tow/salvage boat. It is worth pointing out that in one instance (i.e., for a tugboat 

with a high TRC concentration of 0.39 mg/L), the measured TRC concentration in the source 

(potable) water was 0.70 mg/L. It is also worth noting that only one of 11 respondents (a fishing 

vessel) indicated using chlorine bleach while washing decks, and this particular vessel had a 

measured TRC concentration in the deck washdown sample of 0.38 mg/L and a PHQ of 51. 

TSS in most of the deck washdown water samples collected exceeded the secondary 

treatment effluent limitation benchmark of 30 mg/L. However, 27 of 32 PHQs calculated for 

these samples were below 10 (Figure 3.3.6), and all five TSS samples with PHQs>10 (max PHQ 

= 17.7) were associated with tugboats. As discussed above, in the one potable water sample for 

which TSS was measured, TSS was not detected. 

BOD was measured in 22 deck washdown water samples that exceeded EPA’s secondary 

treatment effluent limit of 30 mg/L (Figure 3.3.6). As indicated above, the vessels with the 

highest level of exceedance (PHQs > 5) were associated with three tugboats, a fishing 

(shrimping) vessel, and the supply boat. 

EPA compared HEM and SGT-HEM concentrations measured in deck washdown 

samples to the existing international and U.S. regulatory limit of 15 ppm (15 mg/L) for oil and 

grease discharge. HEM and SGT-HEM were detected in all of the deck washdown water 

samples, with concentrations ranging from 1.2 to a very high 133 mg/L for HEM and 0.91 to a 

comparably high 84 mg/L for SGT-HEM. Based on the regulatory limit of 15 mg/L, PHQs 

exceeded one in only six of 29 vessels sampled for HEM and two in the 29 vessels sampled for 

SGT-HEM. The highest PHQs for both parameters corresponded with the supply boat and a 

tugboat, with PHQs of 4.7 and 8.9 for HEM and 1.2 and 5.6 for SGT-HEM, respectively. Note, 

oil and grease were not detected in the two potable water samples collected in this sampling 

program. 

162 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

163 

To summarize, just under a third of the vessels sampled had concentrations of TRC in 

deck washdown samples above the reporting limit of 0.10 mg/L. Of these seven samples, the 

measured TRC concentrations (as high as 0.80 mg/L) that exceeded the screening benchmark 

were not associated with any one particular class of vessel. For TSS, however, one vessel type 

(tugboats) had the highest number of exceedances. The elevated TSS in deck washdown water 

samples from tugboats may be caused by a less frequent washdown on these vessels compared 

with vessels such as fishing vessels. Just over two-thirds of vessels (22 out of 32) exceeded the 

most stringent screening benchmark for BOD; however, as in the case with TRC, no one 

particular class of vessels had a higher number of exceedances than other classes. 

Oil and grease are generally not of concern for this type of discharge, nor are any of the 

other physical parameters that were measured (conductivity, dissolved oxygen, pH, temperature, 

salinity). TOC was detected in all samples ranging from 3.6 to a very high 350 mg/L (one of the 

tugboats with high HEM). Organic carbon strongly complexes metals in both freshwater and 

saltwater matrices, and like the competing cations such as calcium and magnesium, renders 

dissolved metals less bioavailable and less likely to be rapidly available for biological organisms. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.3.6. Results of Deck Washdown Water Sample Analyses for Classical Pollutants1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Biochemical Oxygen Demand (BOD) mg/L 32 30 94 110 56 4.7 14 92 Chemical Oxygen Demand (COD) mg/L 32 32 100 390 160 24 52 90 570 Conductivity mS/cm 26 26 100 7.7 1.0 0.24 0.37 0.50 13 Dissolved Oxygen mg/L 26 26 100 7.2 7.7 1.6 1.8 6.3 8.9 Hexane Extractable Material (HEM) mg/L 29 26 90 14 2.8 1.7 12 pH SU 30 30 100 7.7 7.6 7.0 7.0 7.2 7.9 Salinity ppt 24 24 100 4.9 0.60 0.10 0.20 0.23 8.0 Silica Gel Treated HEM (SGT-HEM) mg/L 29 22 76 7.0 1.7 0.45 3.8 Sulfide mg/L 3 2 67 0.011 0.011 0.017 Temperature C 31 31 100 21 21 7.5 9.0 13 29 Total Organic Carbon (TOC) mg/L 25 25 100 44 24 3.6 5.0 7.1 52 Total Residual Chlorine mg/L 31 7 23 0.12 Total Suspended Solids (TSS) mg/L 32 32 100 170 120 27 31 59 250 Turbidity NTU 31 31 100 150 110 4.1 36 58 190 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

164 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

165 

Figure 3.3.5. Box and Dot Density Plot of Classical Pollutants Measured in Samples of Deck 

Washdown Water 

1000.00

BOD (mg/l)

COD (mg/l)

Cond (mS/cm)

DO (mg/l)

HEM (mg/l)

SGT-H (mg/l)

Salin. (ppt)

Sulf. (mg/l)

TOC (mg/l)

TRC (mg/l)

TSS (mg/l)

Temp. (C)

Turb. (NTU)

pH (SU)

Classical Pollutants

0.01

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

BOD (mg/l)

COD (mg/l)

Cond (mS/cm)

DO (mg/l)

HEM (mg/l)

SGT-H (mg/l)

Salin. (ppt)

Sulf. (mg/l)

TOC (mg/l)

TRC (mg/l)

TSS (mg/l)

Temp. (C)

Turb. (NTU)

pH (SU)

Classical Pollutants

0.1

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Figure 3.3.6. Box and Dot Density Plot of Potential Hazard Quotients for Classical 

Pollutants in Samples of Deck Washdown Water

(Note: Replacement values for non-detects are circled. Also, PHQs for sulfide are not shown in the figure, but are 

mentioned in the text). 

166 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.3.3 Pathogen Indicators (Microbiologicals) 

Selected deck washdown water samples were analyzed for the pathogen indicator 

bacteria E. coli, enterococci, and fecal coliform. Sampling for pathogens was limited to fishing 

vessels since EPA could not identify likely potential sources of pathogens in deck washdown 

discharges on other vessel types. EPA targeted select fishing vessels to attain the best crossrepresentation possible based on available funding and proximity to qualified subcontractor 

laboratories to meet sample hold times (< 6 hours). The types of fishing vessels sampled 

included three shrimping (trawler) boats in Louisiana, two ground fishery trawlers in 

Massachusetts, and a gillnetter boat in Alaska. All vessels indicated that their decks are washed 

frequently throughout the day (after or between catches, after unloading, etc.), and while pierside 

and underway (nearshore and farshore). Table 3.3.7 summarizes the analytical results. 

Concentrations were determined for each pathogen using the same (E. coli, enterococci) or 

comparable methods (fecal coliform). 

Figure 3.3.7 shows the variability of the values measured for the pathogens in deck 

washdown water samples from the various fishing vessels. Measured concentrations of E. coli

range from 20 MPN/100 ml for one of the shrimping trawlers to 8,336 MPN/100 ml for one of 

the ground fishery trawlers in Massachusetts. It should be noted, however, that the water the 

ground fishery trawler used for desk washing was ambient (harbor) water receiving stormwater 

and combined sewer overflow from a storm event. The measured concentration of E. coli in the 

ambient water at that location was 24,200 MPN/100 ml. Excluding this outlier, the concentration 

of E. coli from only one vessel (shrimper; concentration = 650 MPN/100 ml) exceeded EPA’s 

most stringent freshwater bathing NRWQC of 126 MPN/100 ml by more than a factor of five 

(PHQ = 5.1), as illustrated in Figure 3.3.8. EPA collected multiple samples from another 

shrimping vessel in Louisiana to measure E. coli in prefishing deck washdown water, postfishing 

water, without catch rinse water, and with catch rinse water. For this vessel, E. coli

concentrations ranged from a low of 10 (prefishing sample) to a high of only 50 MPN/100 ml 

(without catch rinse). The concentrations of E. coli were largely unaffected by either the addition 

of catch to the vessel (as E. coli concentrations in prefishing and postfishing deck washdown 

samples were similar) or the process of rinsing the catch while on deck.

The enterococci values measured in a deck washdown water samples ranged from 1.5 to 

1,300 MPN/100 ml, and follow the same general pattern as E. coli (Figure 3.3.7). Excluding the 

previously described example of the trawler in Massachusetts, which was directly influenced by 

high levels of enterococci in the ambient water resulting from storm-related combined sewage 

overflow (5,100 MPN/100 ml), the deck washdown water samples from two vessels (both 

shrimpers; concentrations = 637 and 914 MPN/100 ml, respectively) exceeded EPA’s most 

stringent bathing NRWQC for enterococci of 33 MPN/100 ml (freshwater) and 35 MPN/100 ml 

(saltwater) by factors of nearly 20 and 30 respectively (Figure 3.3.8). In contrast to E. coli, 

however, analysis of the multiple samples collected for enterococci in prefishing deck washdown 

167 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

168 

 

water (540 MPN/100 ml), postfishing water (8 MPN/100 ml), without catch rinse (1,200 

MPN/100 ml), and with catch rinse (801 MPN/100 ml) for the shrimping vessel in Louisiana 

indicate that their deck washing process appeared to reduce the presence of the pathogen in deck 

washdown discharge. 

The concentrations of fecal coliform bacteria measured in a deck washdown water 

samples are all substantial (ranging from 91 to 600 CFU/100 ml27), except for the very low 

concentration of 0.75 CFU/100 ml for the gillnetting vessel in Alaska (Figure 3.3.7). The 

associated PHQs for fecal coliform range from 0.05 (gillnetter) to 43 (one of the shrimping 

boats), as illustrated in Figure 3.3.8. The PHQs for this pathogen are based on the NRWQC of 14 

MPN/100 ml for shellfish harvesting. As with enterococci, the multiple samples measured for 

fecal coliform bacteria in prefishing deck washdown water (0 CFU/100 ml), postfishing water (6 

CFU/100 ml), without catch rinse (1,630 CFU/100 ml), and with catch rinse (620 CFU/100 ml) 

for the shrimping vessel indicate that their deck washing process did not increase (and seemed to 

reduce) the presence of this pathogen in deck washdown discharge. The single potable water 

sample taken while onboard a shrimping vessel pierside in Louisiana was free of all pathogens. 

The data collected for this study show that, while the three groups of pathogens are 

present in deck washdown discharge samples from commercial fishing vessels, concentrations 

are variable, and the source of the water used for deck washdown can greatly influence the 

background bacteria levels. Of the three pathogen groups, fecal coliform are present at 

concentrations exceeding EPA’s most stringent criteria more often than enterococci and E. coli, 

in that order. 

27 Excluding the outlier value of 8,050 CFU/ml from the ground fishery trawler in Maine influenced by the storm 

event. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.3.7. Results of Deck Washdown Water Sample Analyses for Pathogen Indicators1

Analyte2 Units3 No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90

E. Coli by MPN MPN/100 ml 5 5 100 1900 160 20 20 62 4500 8Enterococci by MPN MPN/100 ml 5 5 100 580 640 1.5 1.5 27 1100 1Fecal Coliform by MF CFU/100 ml 6 6 100 1600 560 0.75 0.75 68 2500 8

Notes:  (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in thi

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) MPN = Most Probable Number; MF = Membrane Filtration. (3) CFU = Colony Forming Units. (4) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

169 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

E. Coli

Enterococci

Fecal Colifo

Pathogen Indicators

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Figure 3.3.7 Box and Dot Density Plot of Pathogen Indicator Concentrations Measured in 

Samples of Deck Washdown Water

(Note: Corresponding units are MPN/100 ml for E. coli and enterococci, and CFU/100 ml for fecal coliform). 

170 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

E. Coli

Enterococci

Fecal Colifo

Pathogen Indicators

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Figure 3.3.8. Box and Dot Density Plot of Potential Hazard Quotients for Pathogens in 

Samples of Deck Washdown Water 

171 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.3.4 Nutrients 

Deck washdown discharge was also characterized for nutrient levels. Nutrient pollution, 

including nitrogen, phosphorus, and numerous micronutrients, is a component of certain vessel 

discharges and a major source of water quality degradation throughout the United States (USGS, 

1999). Deck washdown discharges from all vessel types were expected to contain potentially 

high levels of phosphorus because of the wide-spread use of detergents for deck cleansing. Deck 

washdown discharges from commercial fishing vessels were also expected to contain potentially 

elevated ammonia concentrations for the same reason, as well as from biological wastes from 

fish and shellfish catch. In addition to total phosphorus and total ammonia (as nitrogen), deck 

washdown water samples were also analyzed for nitrate/nitrite nitrogen (inorganic nitrogen) and 

TKN, the sum of organic nitrogen (including toxic ammonia nitrogen) (see Table 3.3.8). 

Concentrations of nitrate/nitrite nitrogen in deckwash discharge samples range from 

0.025 to 6.5 mg/L (see Figure 3.3.9). An interesting note is that the deck washdown water 

samples for commercial fishing vessels of all types did not exceed 0.50 mg/L while all other 

vessels exceeded this value. The five highest nitrate/nitrite concentrations (ranging from 2.5 to 

6.5 mg/L) were analyzed in samples from three tugs and two tow/salvage vessels. It is important 

to note, however, that most samples of deck washdown on fishing vessels were collected 

onboard fishing vessels pierside and not when fishing activity was occurring. In the two cases 

where deck washdown samples were collected where fishing activities were taking place, the 

samples were collected towards the end of the deck washdown activity and may not have 

captured potentially higher levels of nitrate/nitrite from biological wastes. 

The concentrations determined for TKN (sum of organic nitrogen) show the 

concentration range spans two orders of magnitude, from 0.05 to 40 mg/L (see Figure 3.3.9). In 

contrast to the nitrate/nitrite samples, the TKN concentrations from all vessels were evenly 

distributed across the entire concentration range. The two highest TKN concentrations (by more 

than a factor of two) correspond to a trolling vessel and a tugboat, with TKN concentrations of 

28 and 40 mg/L, respectively. 

Ammonia is the only nutrient form for which there are currently numeric NRWQC 

established to protect against its toxic effects. Only five of 31 vessels contained ammonia in deck 

washdown water samples slightly above (1.2 to 1.8 mg/L ammonia as nitrogen) the most 

stringent 2006 NRWQC of 1.2 mg/L, the freshwater chronic aquatic life criterion for total 

ammonia as nitrogen (see Figure 3.3.10). These values correspond with deck washdown water 

samples collected from two tow/salvage boats, two fishing vessels, and the recreational vessel. 

The benchmark for total phosphorus of 0.1 mg/L from the 1986 EPA Gold Book was 

exceeded in samples collected from all but one of the 31 vessels. The highest total phosphorus 

concentration of 22 mg/L from a tugboat exceeded the benchmark by a factor of 220 (see Figure 

172 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

173 

3.3.10). This concentration was 6.5 times higher then the next highest measured concentration of 

3.4 mg/L from a trolling vessel. The deck washdown water samples for phosphorus from all 

vessels were generally evenly distributed across the entire concentration range. 

Total ammonia in ambient and service water ranged from below detection to 0.93 mg/L 

and from below detection to 0.73 mg/L, respectively (all below the most stringent 2006 NRWQC 

of 1.24 mg/L). Total phosphorus in ambient and service water ranged from below detection to 

2.0 mg/L and from below detection to 0.52 mg/L, respectively (compared to 0.1 mg/L from the 

1976 EPA Red Book). 

In summary, out of the four nutrient parameters, only total phosphorus is likely a 

potential concern from deck washdown effluent. Twelve of the 19 respondents confirmed using 

standard liquid detergents aboard their vessels for deck washing, the expected source of total 

phosphorus in deck washdown discharges. However, ambient and domestic service water are 

also likely sources of phosphorus in a meaningful percentage of instances. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.3.8. Results of Deck Washdown Water Sample Analyses for Nutrients1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Ammonia As Nitrogen (NH3-N) mg/L 31 31 100 0.53 0.32 0.058 0.074 0.10 0.81 1.5 Nitrate/Nitrite (NO3/NO2-N) mg/L 32 27 84 1.4 1.5 0.16 1.9 2.7 Total Kjeldahl Nitrogen (TKN) mg/L 31 30 97 6.0 3.6 1.4 1.8 6.6 11 Total Phosphorus mg/L 31 31 100 1.7 0.79 0.060 0.15 0.44 1.6 2.9 Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

174 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

175 

Figure 3.3.9. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of 

Deck Washdown Water

(Note: NH3-N=Ammonia as Nitrogen, NO3/NO2-N= Nitrate/Nitrite Nitrogen, TKN=Total Kjeldahl Nitrogen, and 

Total Phosph (truncated)=Total Phosphorus). 

NH3-N

NO3/NO2-N

TKN

Total Phosph

Nutrients

0.1

1.0

10.0

C

o

n

c

e

n

t

r

a

tio

n

m( g

/

L)
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

NH3-N

NO3/NO2-N

TKN

Total Phosph

Nutrients

0.1

1.0

10.0

100.0

p

o

t

e

n

tial h

a

z

a

r

d

q

u

o

tie

n

t

Figure 3.3.10. Box and Dot Density Plot of Potential Hazard Quotients for Nutrients in 

Samples of Deck Washdown Water

(Note: NH3-N=Ammonia as Nitrogen, NO3/NO2-N= Nitrate/Nitrite Nitrogen, TKN=Total Kjeldahl Nitrogen, and 

Total Phosph (truncated)=Total Phosphorus). 

176 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

177 

3.2.3.5 Long-Chain Nonylphenols 

Deck washdown water samples from 29 vessels were analyzed for 27 long-chain 

alkylphenol ethoxylates: 16 NPEOs and 5 OPEOs (see Table 3.3.9). The NPEOs with the longest 

ethoxylate chains (i.e., less degraded products (NP18EO through NP10EO)) were detected in 

slightly under a third of the vessels (nine of 29), with concentrations increasing as ethoxylate 

chain is reduced (i.e., concentrations increasing from NP18EO to NP10EO because the longerchain products found in commercial formulations are quickly degraded). The OPEO with the 

longest ethoxylate chain (OP12EO) was also detected in about a third of the vessels (see Table 

3.3.9). As with NPEOs, the OPEO concentrations generally increase as the ethoxylate chain is 

reduced, except that no OPEOs with ethoxylate chains smaller than OP7EO were detected 

(similar to the situation in packing gland effluent; see Section 3.2.2.5). 

Of the several vessels where NPEOs were detected in the longer (NP18EO through 

NP10EO) ethoxylated compounds, only three of those vessels also had detectable concentrations 

of NPEOs of the shortest chain (NP3EO), albeit at very low concentrations ranging from 0.80 to 

29 μg/L. These were tow/salvage vessels, one of which confirmed using liquid detergent 

(PalmoliveTM) for deck washing (NP3EO concentration of 29 μg/L in deck washdown sample). 

A tugboat had the only measured concentration of OP8EO in its deck washdown water sample at 

a concentration of 19 μg/L. 

Total NPEO concentrations could be calculated from summed concentrations of 

individual chain lengths for five of the 29 vessels: three tow/salvage vessels and two tour boats 

(see Figure 3.3.11). The concentrations of total NPEOs ranged from 30 to 8,330 μg/L. 

As discussed in previous subsections (see Sections 3.2.1.7 (bilgewater) and 3.2.2.5

(packing gland effluents)), while there are no NRWQC for the sum of individual ethoxylate 

chains of NPEOs or OPEOs, these compounds will ultimately degrade to NP in fresh and salt 

water over time under all conditions. The NRWQC for NP in salt water based on chronic toxicity 

to aquatic organisms is 1.7 μg/L. EPA is uncertain as to exactly how much NP might be 

generated from the degradation of NPEO and OPEO isomers under a given harbor scenario and 

water quality condition (see Section 1.6.6 of this report). However, neither total NPEO or OPEO, 

nor any of the different isomers, were detected in ambient water at the locations where the 

vessels were sampled. Service water (generally city tapwater pierside) was not analyzed for longor short- chain nonylphenol and octylphenol ethoxylates. 

 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.3.9. Results of Deck Washdown Water Sample Analyses for Long-Chain Nonylphenols1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 

Total Nonylphenol Polyethoxylates μg/L 29 5 17 540 Nonylphenol octodecaethoxylate (NP18EO) μg/L 29 12 41 1.5 Nonylphenol heptadecaethoxylate (NP17EO) μg/L 29 9 31 3.4 Nonylphenol hexadecaethoxylate (NP16EO) μg/L 29 10 34 7.4 Nonylphenol pendecaethoxylate (NP15EO) μg/L 29 9 31 14 Nonylphenol tetradecaethoxylate (NP14EO) μg/L 29 9 31 25 Nonylphenol tridecaethoxylate (NP13EO) μg/L 29 9 31 44 Nonylphenol dodecaethoxylate (NP12EO) μg/L 29 8 28 64 Nonylphenol undecaethoxylate (NP11EO) μg/L 29 9 31 86 Nonylphenol decaethoxylate (NP10EO) μg/L 29 9 31 91 Nonylphenol nonaethoxylate (NP9EO) μg/L 29 8 28 88 Nonylphenol octaethoxylate (NP8EO) μg/L 29 8 28 75 Nonylphenol heptaethoxylate (NP7EO) μg/L 29 7 24 61 Nonylphenol hexaethoxylate (NP6EO) μg/L 29 6 21 34 Nonylphenol pentaethoxylate (NP5EO) μg/L 29 6 21 19 Nonylphenol tetraethoxylate (NP4EO) μg/L 29 4 14 11 Nonylphenol triethoxylate (NP3EO) μg/L 29 3 10 4.9 Octylphenol dodecaethoxylate (OP12EO) μg/L 29 8 28 1.4 Octylphenol undecaethoxylate (OP11EO) μg/L 29 2 6.9 1.8 Octylphenol decaethoxylate (OP10EO) μg/L 29 4 14 3.6 Octylphenol nonaethoxylate (OP9EO) μg/L 29 5 17 3.8 Octylphenol octaethoxylate (OP8EO) μg/L 29 1 3.4 10 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

178 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

0 2 4 6 8 10 12 14 16 18 20 22 24

Nonylphenols

0.01

0.10

1.00

10.00

100.00

1000.00

C

o

n

c

e

ntratio

n (u

g/L)

Figure 3.3.11. Box and Dot Density Plot of Nonylphenol Concentrations Measured in 

Samples of Deck Washdown Water 

Nonylphenol parameters are identified as follows: 

(1) Total Nonylphenol 

Polyethoxylates 

(2) Nonylphenol 

octodecaethoxylate (NP18EO) 

(3) Nonylphenol 

heptadecaethoxylate (NP17EO) 

(4) Nonylphenol 

hexadecaethoxylate (NP16EO) 

(5) Nonylphenol 

pendecaethoxylate (NP15EO) 

(6) Nonylphenol 

tetradecaethoxylate (NP14EO) 

(7) Nonylphenol 

tridecaethoxylate (NP13EO) 

(8) Nonylphenol 

dodecaethoxylate (NP12EO) 

(9) Nonylphenol 

undecaethoxylate (NP11EO) 

(10) Nonylphenol 

decaethoxylate (NP10EO) 

(11) Nonylphenol 

nonaethoxylate (NP9EO) 

(12) Nonylphenol 

octaethoxylate (NP8EO) 

(13) Nonylphenol 

heptaethoxylate (NP7EO) 

(14) Nonylphenol 

hexaethoxylate (NP6EO) 

(15) Nonylphenol 

pentaethoxylate (NP5EO) 

(16) Nonylphenol 

tetraethoxylate (NP4EO) 

(17) Nonylphenol triethoxylate 

(NP3EO) 

(18) Octylphenol 

dodecaethoxylate (OP12EO) 

(19) Octylphenol 

undecaethoxylate (OP11EO) 

(20) Octylphenol decaethoxylate 

(OP10EO) 

(21) Octylphenol 

nonaethoxylate (OP9EO) 

(22) Octylphenol octaethoxylate 

(OP8EO) 

179 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.3.6 Volatile and Semivolatile Organic Chemicals 

VOCs and SVOCs were not targeted for deck washdown water sample collection in this 

study because these compounds were not expected to be found in common deck washdown on 

most vessels28. In two cases during scheduled cleanings of the decks of two tow/salvage vessels, 

however, there was a noticeable oily sheen and where fuel was spilled at the fueling location 

while samplers were onboard the vessels. Samples of deck washdown water were taken in these 

instances and analyzed for VOCs and SVOCs (see Table 3.3.10). 

Of the 70 VOCs that were analyzed for in the two deck washdown samples, only 12 were 

detected in one or more of the two samples. Of these 12 VOCs, only acetone, chloroform, and 

toluene were detected in both samples. In one sample from the vessel with the oily sheen; 

acetone was detected at 20 μg/L. Figure 3.3.12 contains all the samples that were detected, the 

other five samples were detected with very low values. Benzene, ethylbenzene, and xylene 

(compounds associated with fuel oil spills) were detected in one of the two samples at 

surprisingly low levels. The PHQ of 13 for the benzene sample that was below detection levels 

was an artifact of the relatively high reporting limit of 25μg/L compared to the screening 

benchmark of 2.2 μg/L. PHQs for only two VOCs, dibromochloromethane and 

bromodichloromethane exceeded the benchmark (see Figure 3.3.13), which were artifacts of the 

reporting limits which were as high as 25μg/L compared to the screening benchmarks of 0.4 

μg/L and 0.55 μg/L, respectively. Both these were formerly used as flame retardants and as an 

intermediate in chemical manufacturing. 

Similarly, of the 62 SVOCs that were analyzed for in the two deck washdown samples, 

only three were detected in one or more of the two samples: bis(2-ethylhexyl) phthalate, 

caprolactam, and di-n-butyl phthalate (data not shown due to so few analytes detected). Levels 

detected in the latter two SVOCs are unremarkable. The concentration of bis(2-ethylhexyl) 

phthalate in the one sample where it was detected (i.e., the tow/salvage vessel with the oily 

sheen), however, was sufficiently high (6.7 μg/L) such that the associated PHQ, based on the 

most conservative screening benchmark of 1.2 μg/L (human health criteria), was 5.6 (data not 

shown). As previously noted, bis(2-ethylhexyl) phthalate is a manufactured chemical that is 

commonly added to plastics to make them flexible. Phthalates in general are known to interfere 

with reproductive health and liver and kidney function in both animals and humans (Sekizawa et 

 

28 It is worth noting that solvents in cleaning agents may be used for certain activities such as above-water-line hull 

cleaning. Samples associated with above-water-line hull cleaning were not collected during this study because none 

of the vessels engaged in such an activity while EPA’s sampling crew was aboard the vessel. During a survey 

collected while onboard the vessels, however, 11 of 16 respondents confirmed that they do perform above-water-line 

hull cleaning occasionally on their vessels.

180 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

181 

al., 2003; DiGangi et al., 2002). Bis(2-ethylhexyl) phthalate was not detected in the associated 

ambient water sample collected at the site corresponding with the two tow/salvage vessels, but 

di-n-butyl phthalate was (ambient concentration of 1.1 μg/L). 

Di-n-butyl phthalate was the only SVOC detected in ambient water samples collected in 

association with the deck washdown samples collected in the study. No VOCs were detected in 

ambient samples. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.3.10. Results of Deck Washdown Water Sample Analyses for VOCs and SVOCs1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% M

VOCs

1,2,4-Trimethylbenzene μg/L 2 1 50 13 0.30 0.30 0.30 1,3,5-Trimethylbenzene μg/L 2 1 50 13 0.090 0.090 0.090 Acetone μg/L 2 2 100 13 20 5.5 5.5 5.5 20 20 Benzene μg/L 2 1 50 13 0.3 0.3 0.3 Bromodichloromethane μg/L 2 1 50 13 1.2 1.2 1.2 Chloroform μg/L 2 2 100 1.3 1.5 1.0 1.0 1.0 1.5 1.5 Dibromochloromethane μg/L 2 1 50 13 0.7 0.70 0.70 Ethylbenzene μg/L 2 1 50 13 0.10 0.10 0.10 m-,p-Xylene (sum of isomers) μg/L 2 1 50 25 0.40 0.40 0.40 O-Xylene μg/L 2 1 50 25 0.20 0.20 0.20 Toluene μg/L 2 2 100 0.65 0.70 0.60 0.60 0.60 0.70 0.70 

SVOCs

Bis(2-ethylhexyl) phthalate μg/L 2 1 50 4.7 6.7 6.7 6.7 Caprolactam μg/L 2 2 100 79 100 56 56 56 100 100 Di-n-butyl phthalate μg/L 2 1 50 2.5 2.4 2.4 2.4 Naphthalene μg/L 2 1 50 13 0.40 0.40 0.40 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

182 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

183 

Figure 3.3.12. Box and Dot Density Plot of Volatile Organic Chemical Concentrations 

Measured in Samples of Deck Washdown Water

VOCs are identified as follows: 

(1) 1,2,4-Trimethylbenzene 

(2) 1,3,5-Trimethylbenzene 

(3) Acetone 

(4) Benzene 

(5) Bromodichloromethane 

(6) Chloroform 

(7) Dibromochloromethane 

(8) Ethylbenzene 

(9) m-,p-Xylene (sum of 

isomers) 

(10) O-Xylene 

(11) Toluene 

0 2 4 6 8 10 12

VOCs

0.1

1.0

10.0

C

o

n

c

e

ntr

atio

n (u

g

/

L)
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

184 

Figure 3.3.13. Box and Dot Density Plot of Potential Hazard Quotients for VOCs in 

Samples of Deck Washdown Water

VOCs are identified as follows (replacement values for non-detects are circled): 

(1) 1,2,4-Trimethylbenzene 

(2) 1,3,5-Trimethylbenzene 

(3) Acetone 

(4) Benzene 

(5) Bromodichloromethane 

(6) Chloroform 

(7) Dibromochloromethane 

(8) Ethylbenzene 

(9) m-,p-Xylene (sum of 

isomers) 

(10) O-Xylene 

(11) Toluene 

0 2 4 6 8 10 12

VOCs

0.0001

0.0010

0.0100

0.1000

1.0000

10.0000

P

ote

ntial H

a

z

a

r

d

Q

u

otie

nt
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.3.7 Summary of the Characterization of Deck Washdown Water 

Table 3.3.11 summarizes the specific analytes within deck washdown and runoff water 

that may have the potential to pose risk to human health or the environment. EPA’s interpretation 

of a realized risk likely posed by these analytes, relative to pollutant loadings, background 

ambient and source water contaminant levels and characteristics, and other relevant information 

useful for this assessment, is presented in Chapter 5. 

Metals were the class of pollutants found most frequently and at concentrations that 

exceeded national water quality criteria in samples of deck washdown discharge. Several 

dissolved metals were measured at PHQs>10, relative to the most stringent benchmarks. Among 

the dissolved metals, copper was the most prevalent, and was measured at PHQ>10 in 

tow/salvage, fire, taxi, tour, and supply vessels. Dissolved cadmium was rarely detected, but had 

the highest exceedance, in a tow/salvage vessel. Dissolved lead exceeded NRWQC benchmarks 

in five of six salvage vessels, three of nine tugboats, one of two tour vessels, the one fire vessel, 

and the one supply vessel. Dissolved zinc exceeded NRWQC benchmarks in five of six 

tow/salvage vessels, as well as in tug, tour, fire, and supply vessels. Among the total metals, 

arsenic and aluminum were the most prevalent, particularly in deck washdown discharges of 

tow/salvage boats (both metals), tugboats (aluminum), and fishing and fire vessels (arsenic). 

Total iron exceedances were also common, with the highest PHQs for total iron occurring in 

tugboats and tow/salvage vessels. Finally, total antimony and manganese exceedances were 

relatively rare, with PHQs in those instances associated mainly with the nonfishing vessels. In 

general, metal discharges were higher in the industrial nonfishing vessels compared to fishing 

vessels. 

Among the conventional pollutants, TRC was the most prevalent, with regard to high 

concentrations and frequency of exceedance of the discharge. The highest PQHs for TRC were 

observed in three of the 11 fishing vessels, the two tour boats, a tow/salvage vessel, and a 

tugboat. TSS and turbidity were the next most important classical pollutants, with high 

occurrences distributed across all vessel classes, but particularly tugboats. The highest 

exceedances of BOD were found in three tugboats, one shrimp vessel, and the supply boat. COD 

and TOC concentrations were similar to BOD concentrations. Oil and grease and sulfide were 

high in only a select few samples (in tugboat, tow/salvage boat, and the supply boat). 

Samples for pathogens were taken from only fishing vessels, with fecal coliform and 

enterococci potentially having the highest concentrations. Levels were high in all vessels except 

for the gillnetting vessel in Alaska. Differences in pathogen loads could be related to location or 

method of fishing (gillnetting vs. trawling). Pathogen loads in deck wash declined after washing 

in all cases. 

Total phosphorus was the only nutrient of potential concern, with high levels found in 

almost all samples, presumably due to the use of detergents in the deck wash practices. Long185 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

186 

chain nonylphenol polyethoxylates of the smallest chain (i.e., NP3EO, most degraded form) were 

found in only three of the tow/salvage vessels, and total nonylphenol polyethoxylates were found 

at high concentrations in two tour vessels. Finally, a moderately high PHQ of 5.6 for bis(2-

ethylhexyl) phthalate was found in the discharge of a tow/salvage vessel with a noticeably oily 

sheen. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

187 

Table 3.3.11. Characterization of Deck Washdown and Runoff Water and Summary of Analytes that May to Pose Risk 

Analytes that May Have the Potential Risk to Pose Risk in Deck Washdown and Runoff Water an

Vessel Type (no. vessels)

Microbiologicals 

Volatile Organic 

Compounds 

Semivolatile 

Organic 

Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Sulfide 

Short-Chain 

Alkylphenol 

Ethoxylates and NP 

Long-Chain 

Alkylphenol 

Ethoxylates 

Fishing (11) 

Fecal 

coliform 

Enterococci 

E. coli 

Cu,Zn Al,As,Fe x 

N

Tugboats (9) Cu,Pb,Zn Al, As,Fe,Mn x 

(in

on

hig

=

Tow/Salvage 

(6) 

Bis(2-

ethylhexyl) 

phthalate 

Cu,Cd,Cr,Pb,

Ni,Zn, 

Al, As,

Fe,Sb x x 

N

Tour (2) Cu,Pb,Zn Al,As x 

Water Taxi (1) Cu Al,As,Fe,M n 

Fire (1) Cu,Cr,Pb As,Al,Fe,S b 

Supply (1) Cu,Cd,Pb, Ni,Zn Al, As, Fe,Mn,Sb x 

Recreational 

(1) Cu,Ni Al, As 

Notes: (1) Analytes are generally bolded when a large proportion of the samples have concentrations exceeding the NRWQC (e.g., 25 to 50 percent), when sev

two or three of five), when a few samples result in PHQs greatly exceeding the screening benchmark (i.e., 100s to 1,000s), or, in the case of oil and greassamples exceed an existing regulatory limit by more than a factor of 2. See text in Section 3.1.3 for a definition of PHQs and Table 3.1 for screening benc

(2) EPA notes that the conclusion of potential risk is drawn from a small sample size, in some cases a single vessel, for certain discharges sampled from included these results in the tables to provide a concise summary of the data collected in the study, but strongly cautions the reader that these conclusionsamples from a given vessel class, should be considered preliminary and might not necessarily represent pollutant concentrations from these discharges class. (3) All dissolved metals identified as possible risks are potentially influenced by the dissolved metal concentrations measured in source water (gene

all vessel types), particularly dissolved Cu and Zn. (4) All total metals identified as possible risks are influenced by total metal concentrations measured in surrounding ambient water (relevant only for vessewashdown (i.e., many fishing vessels performing deck washdown while offshore, certain tug boats (as indicated in vessel survey)). 

(5) Elevated total phosphorus concentrations in deck washdown samples likely influenced by ambient and source water concentrations. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.4 Fish Hold and Fish Hold Cleaning Effluent (Refrigerated Seawater and 

Ice Slurry) 

Refrigerated seawater and ice/ice slurry are the two commonly used methods for 

preserving fish in the fish hold of many fishing vessels. EPA noted that some vessels 

(e.g., large shrimping vessels in the Gulf of Mexico) use dry freezers to preserve their 

catches; however, these vessels do not produce significant amounts of effluent from the 

hold that comes into contact with seafood product and that is later discharged. Lobster 

and crab boats have seawater flow-through tanks used to keep lobsters and crabs alive. 

Both the freezers and flow-through tanks might contain residual seafood material that 

sometimes is discharged when the vessels clean their holds. 

The analytes and parameters detected in fish hold effluent come from the vessel, 

ambient water and potable/service water. Additionally, many of the constituents can 

come from the seafood product itself. If the seafood (e.g., fish, shrimp) are not frozen, but 

preserved in refrigerated seawater or ice slurry, small quantities of organic material from 

the fish (e.g., lipids, protein) will be released as the fish degrade, thereby increasing the 

concentration of those constituents in the discharge. Furthermore, different volumes of 

blood, mucus, and other matter can drain from the seafood into the hold, depending on 

how the fish is butchered or cleaned on deck. For example, salmon, when caught via 

gillnets on gillnetting vessels, are cut at the gills and bled and then placed into the 

refrigerated sea water tanks/on ice before being cleaned (resulting in their internal organs 

and some blood leaking into the water). In contrast, salmon caught on trollers are cleaned 

while the fishing vessel is still at sea and the internal organs are discharged into the 

surrounding waters. Hence, on the salmon trollers, the organs and most of the residual 

blood are not in contact with refrigerated water/ice, and consequently, lower quantities of 

these materials are discharged when the vessel empties its hold at the dock. 

The volume of fish hold water generated by a fishing vessel depends on the size 

of the vessel and the method used for keeping the product fresh. Vessels such as small 

salmon trollers or long-liners that frequent Alaska waters have around 1,500 gallons of 

fish hold storage. Assuming a hold is occupied by approximately 50 percent fish and 35 

to 40 percent ice when the vessel off-loads at the seafood processing facility, the ice, 

which is thrown overboard daily after the fish are unloaded, would result in a fish hold 

discharge of between 500 and 600 gallons for these types of fishing vessels every three to 

seven days (70 to 200 gpd). 

188 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Collecting Fish Hold Ice from a Long Liner 

Fish Hold Ice from a Trawler 

Mid-size fishing vessels, such as gill netters, and purse seiners found in Alaska, 

and shrimp boats in the Gulf of Mexico, have fish hold volumes of between 3,000 and 

5,000 gallons. Assuming a hold contains between 35 and 40 percent of ice/water slurry, a 

189 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

vessel discharges between 1,000 and 2,000 gallons of fish hold water every two to three 

days (333 to 1,000 gpd). 

Larger fishing vessels such as off-shore trawlers found off the coast of New 

England and tenders found in Alaska can have refrigerated seawater holding tanks or ice 

hold tanks with capacities as large as 15,000 gallons. Assuming these fish hold tanks 

contain 30 to 40 percent refrigerated seawater or ice after the seafood is unloaded, the 

fish hold discharge would be between 4,500 and 6,000 gallons. These vessels are 

expected to unload seafood and discharge the fish hold water every three to five days 

(900 to 2,000 gpd). 

Two Examples of Full Fish Hold Tanks on a Tender Vessel 

190 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

EPA collected effluent samples from 31 commercial fishing vessels for this study. 

Samples were collected from the fish holds that were in use on 26 of these vessels. EPA 

generally collected single grab samples from these vessels while the vessels were 

dockside. These samples were usually collected while the effluent was being discharged, 

but they were occasionally collected directly from the fish hold. EPA analyzed samples 

for both total and dissolved metals, classical pollutants, pathogens, and nutrients. EPA 

also analyzed three samples from fish holds for nonylphenols. 

The fish hold tank is cleaned after the catch has been off-loaded at the seafood 

processing facility, so the frequency of fish hold cleaning depends on the type and 

amount of fish being caught. For example, off-shore trawlers in New England might only 

clean the fish hold tank every three to five days when they return to the fish processing 

facility. Small fishing vessels such as salmon trollers and long-liners in Alaska off-load 

the catch every three to seven days. Fish tenders and purse seiners with refrigerated 

seawater tanks might clean the tanks every couple of days when they return to the fish 

processing facility. 

On small fishing boats such as trollers and long-liners, and mid-size fishing boats 

such as gill netters, fish holds are typically cleaned using a garden hose at a flow rate of 

between 10 and 12 gpm. Fish hold cleaning is completed in 15 minutes or less, resulting 

in a discharge of between 150 and 200 gallons per day. Larger vessels such as off-shore 

trawlers found in New England and large tenders in Alaska also use a garden hose to 

wash down the fish hold tanks; however, cleaning these tanks requires approximately 30 

minutes. EPA estimated the volume of fish hold cleaning water discharge for these 

vessels ranges between 300 and 400 gallons per cleaning (60 to 200 gpd depending on 

frequency). 

EPA was able to collect samples of the fish hold cleaning water discharge from 

nine vessels. These samples were analyzed for the same constituents as fish hold effluent 

plus nonylphenols. Nonylphenols are suspected pollutants associated with cleaning 

products. 

3.2.4.1 Metals 

Fish Hold Effluent

Samples of refrigerated cooling water and ice slurry from 26 fish holds were 

analyzed for dissolved and total concentrations of 22 metals. The analytical results are 

summarized in Table 3.4.1 (total metals data) and Table 3.4.2 (dissolved metals data) for 

the 19 metals that were detected in one or more fish hold effluent samples. Figures 3.4.1 

and 3.4.2 present these same results for total and dissolved metals, respectively, 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

normalized by the lowest NRWQC where applicable. The following metals were detected 

in all fish hold water samples: 

 Total aluminum 

 Dissolved and total barium 

 Dissolved and total calcium 

 Dissolved and total cobalt 

 Dissolved and total iron 

 Dissolved and total potassium 

 Dissolved and total sodium 

 Dissolved and total vanadium 

 Dissolved and total zinc 

Concentrations of a number of other metals were measured for 50 percent or more 

of the samples analyzed: 

 Dissolved aluminum 

 Total arsenic 

 Dissolved and total copper 

 Dissolved and total magnesium 

 Dissolved and total manganese 

 Dissolved and total potassium 

 Total silver. 

Several metals for which EPA tested had concentrations that were notable. These 

metals include dissolved and total arsenic, and dissolved copper, selenium, and zinc (see 

Figures 3.4.1 and 3.4.2). A small percentage of the samples contained all the metals 

which EPA regularly analyzes; however, metals such as lead, nickel, and selenium were, 

with a few notable exceptions, in concentrations below PHQs at the point of discharge 

(see Figures 3.4.3 and 3.4.4). EPA analyzed for and detected dissolved and total barium, 

cobalt, iron, potassium, silver, sodium, and vanadium in only two samples. All of the 

detected concentrations in the two samples were low, except for iron. EPA also analyzed 

for antimony, beryllium, and thallium in these two samples and did not detect any of 

these metals. 

The concentrations of many of the metals that were detected in fish hold 

discharges are not unexpected as fish holds generally have numerous exposed metal 

surfaces. In addition, the pumps used to add water to the hold might also add low 

concentrations of metals. Finally, metallic fishing equipment, deck surfaces, and other 

materials sometimes come in contact with the fish or water that runs into the hold. 

Some metal concentrations, particularly mineral salts, appear to be primarily a 

result of background concentrations in the ambient water. For example, aluminum, 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

barium, calcium, iron, magnesium, sodium, and potassium appear to be primarily 

influenced by background concentrations. Other metals that had measurable 

concentrations (e.g., arsenic, copper, manganese, and zinc) appear to result largely from 

mechanically refrigerated water used to cool the sea water to preserve seafood catch, 

adding ice to do the same, or possibly, from the seafood catch itself, or from any 

combination of the three. 

Several metals were detected in at least one sample of fish hold effluent with PHQ 

values of greater than 1 (see Figures 3.4.3 and 3.4.4). For total metals, this included 

aluminum, arsenic, copper, iron, and manganese. However, as discussed above, 

aluminum concentrations appear to be primarily influenced by ambient water background 

concentrations. Total copper concentrations exceeded the total copper benchmark based 

on human health (for consumption of water and aquatic organisms) of 1,300 μg/L by a 

small fraction in two samples (Table 3.4.1). These total concentrations, however, could 

pose potential risk to the aquatic environment because the human health criteria of 1,300 

μg/L is significantly higher than the 3.1 μg/L benchmark used for dissolved copper based 

on the saltwater chronic ambient water quality criterion for the protection of aquatic life. 

When high levels of particulate copper are discharged, some of the particulate copper will 

likely convert to dissolved copper and be made bioavailable to aquatic life. EPA collected 

only two samples for analysis of total iron, one of which had a PHQ value of five and the 

other eight. 

Another metal with high PHQ values is total arsenic. The PHQ values for total 

arsenic ranged from between more than 100 to more than 20,000 (Figure 3.4.3)29. One 

reason for these extreme PHQ values is the exceptionally low screening benchmark of 

0.018 μg/L for total arsenic. Nonetheless, concentrations of total arsenic in the upper end 

ranges of these measurements are a possible environmental concern. These discharges 

may have the potential to cause or contribute to exceedances of water quality standards, 

particularly in areas where multiple fishing vessels discharge their holds into the same 

waters within the same time period. 

Several dissolved metals, including arsenic, cadmium, copper, iron, nickel, and 

selenium, also had PHQs above 1 (see Figure 3.4.4). Dissolved arsenic samples resulted 

in PHQs of approximately 9-10 for two discharges; one was from a shrimping vessel 

from the Gulf Coast and the other from a ground fishery vessel in New England, while a 

third boat ground fishery vessel in New England had a PHQ value of just over 2. There 

was also only one sample which had a PHQ value for cadmium of approximately 5. Only 

 

29 While EPA suspects the highest concentration of total arsenic (and total selenium) from a shrimping 

vessel might be slightly elevated due to positive interference, measured concentrations of arsenic in fish 

hold effluent from other similar vessels were absent positive interference and nearly as high. Therefore, 

EPA believes the measured concentrations of total arsenic (and to a lesser extent selenium) from the 

shimping vessel to reasonably represent true effluent concentrations for the discharge. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

194 

 

four of the 26 values exceeded a PHQ value of 1 for dissolved nickel, and none exceeded 

a value of 2. Dissolved selenium had 6 samples exceed a PHQ value of 1 (the highest 

value of which was approximately 12). Dissolved zinc had numerous PHQ values of 

greater than 1, but none greater than 10. Dissolved copper had numerous samples that 

exceeded the PHQ value of 1, with more than 25 percent of these samples having a PHQ 

value of greater than 10. 

The high dissolved arsenic concentrations were observed exclusively from three 

vessels; a shrimping boat (345 μg/L)30 and two ground fishery trawlers (74 and 310 

μg/L). Ambient water concentrations indicate that the arsenic likely did not come from 

the surrounding water, although dissolved arsenic was measured at a substantial level of 

26 μg/L in the ambient water where the shrimping vessel was sampled. Another possible 

explanation is entrainment of arsenic contaminated sediments on nets. Each of the vessels 

with high arsenic values (trawlers and shrimp boats) use nets that drag the ocean floor. 

When nets are retrieved and emptied on the deck of the vessel, entrained sediments from 

the ocean floor could migrate into the fish holds along with the fish and shrimp. One 

other possible source includes organic arsenic compounds that are primarily found in 

organisms living in the sea. Based on the limited data collected, EPA cannot identify the 

specific source(s) of the high dissolved arsenic values at this time. 

In summary, some samples of dissolved copper in fish hold effluent discharges 

were well above the PHQ screening benchmark of 3.1 μg/L based on the 2006 NRWQC 

saltwater chronic aquatic life criterion. Many of these concentrations resulted in PHQs of 

greater than 10, with some upwards of 200. The three elevated concentrations of 

dissolved arsenic could potentially pose an environmental concern, particularly if these 

arsenic concentrations are common in these vessel discharges. Finally, concentrations of 

total arsenic are also high relative to the benchmark, resulting in high PHQ values and 

may have the potential to pose risks to human health if discharged into drinking water 

sources, though almost all fishing vessels operate in marine or estuarine environments 

that are not used for drinking water.

30 While EPA suspects the highest concentration of dissolved arsenic (and dissolved selenium) from a 

shrimping vessel might be slightly elevated due to positive interference from major seawater cations, 

measured concentrations of arsenic in fish hold effluent from other similar vessels were nearly as high, but 

absent positive interference. Therefore, EPA believes the measured concentrations of dissolved arsenic 

(and to a lesser extent selenium) from the shimping vessel to reasonably represent true effluent 

concentrations for the discharge. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.4.1. Results of Fish Hold Effluent Sample Analyses for Total Metals1

Total Metal Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Heavy and Other Metals 

Aluminum μg/L 26 26 100 827 840 89 180 420 900 1800 Arsenic μg/L 26 16 62 40 4.8 13 210 Barium μg/L 2 2 100 98 110 83 83 83 110 110 Cadmium μg/L 26 3 12 0.99 1.9 Chromium μg/L 26 7 27 4.3 2.6 19 Cobalt μg/L 2 2 100 3.7 4.4 2.9 2.9 2.9 4.4 4.4 Copper μg/L 26 24 92 190 40 5.8 12 140 710 Iron μg/L 2 2 100 2000 2500 1600 1600 1600 2500 2500 Lead μg/L 26 9 35 7.1 5.6 31 Manganese μg/L 26 15 58 24 6.6 17 130 Nickel μg/L 26 5 19 7.7 17 Selenium μg/L 26 7 27 12 13 29 Silver μg/L 2 1 50 2.4 2.7 2.7 2.7 Vanadium μg/L 2 2 100 9.2 10 8.1 8.1 8.1 10 10 Zinc μg/L 26 26 100 340 230 27 46 100 450 940 

Cationic Metals 

Calcium μg/L 26 26 100 150000 190000 1900 3000 15000 270000 30000Magnesium μg/L 26 25 96 450000 580000 1800 14000 840000 98000Potassium μg/L 2 2 100 330000 480000 190000 190000 190000 480000 48000Sodium μg/L 2 2 100 1200000 1900000 370000 370000 370000 1900000 19000

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

195 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

196 

Table 3.4.2. Results of Fish Hold Effluent Sample Analyses for Dissolved Metals1

Dissolved Metal Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 9

Heavy and Other Metals 

Aluminum μg/L 26 24 92 490 670 20 60 850 9Arsenic μg/L 26 10 38 31 5.7 1Barium μg/L 2 2 100 64 84 44 44 44 84 Cadmium μg/L 26 1 4 0.77 Chromium μg/L 26 3 12 1.9 Cobalt μg/L 2 2 100 1.8 2.0 1.6 1.6 1.6 2.0 Copper μg/L 26 23 88 96 15 6.0 38 3Iron μg/L 2 2 100 350 360 340 340 340 360 3Lead μg/L 26 3 12 2.3 Manganese μg/L 26 19 73 22 11 28 Nickel μg/L 26 4 15 6.1 Selenium μg/L 26 6 23 9.2 2.5 Silver μg/L 2 2 100 1.3 1.5 1.0 1.0 1.0 1.5 Vanadium μg/L 2 2 100 3.4 3.5 3.2 3.2 3.2 3.5 Zinc μg/L 26 26 100 180 120 24 31 55 240 4

Cationic Metals 

Calcium μg/L 26 26 100 160000 180000 1200 1900 9000 290000 30Magnesium μg/L 26 25 96 480000 560000 770 11000 920000 99Potassium μg/L 2 2 100 330000 470000 180000 180000 180000 470000 47Sodium μg/L 2 2 100 1200000 2000000 360000 360000 360000 2000000 200

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

197 

Figure 3.4.1. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Fish Hold Effluent 

Aluminum

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Silver

Vanadium

Zinc

Total Metals

1

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1000

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

198 

Figure 3.4.2. Box and Dot Density Plot of Dissolved Metals Concentrations 

Measured in Samples of Fish Hold Effluent 

Aluminum

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Silver

Vanadium

Zinc

Dissolved Metals

1

10

100

1000

C

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

199 

Figure 3.4.3. Box and Dot Density Plot of Potential Hazard Quotients for Total 

Metals in Samples of Fish Hold Effluent 

(Note: Replacement values for non-detects are circled. Also, as discussed in the text above, total arsenic is 

a potential concern; however, the exceptionally high PHQ values are due in part to the low human health 

value for total arsenic used as a benchmark). 

Aluminum

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Silver

Vanadium

Zinc

Total Metals

0.001

0.010

0.100

1.000

10.000

100.000

1000.000

10000.000

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Aluminum

Arsenic

Barium

Cadmium

Chromium

Cobalt

Copper

Iron

Lead

Manganese

Nickel

Selenium

Silver

Vanadium

Zinc

Dissolved Metals

0.1

1.0

10.0

100.0

P

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nt Figure 3.4.4. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved 

Metals in Samples of Fish Hold Effluent 

(Note: Replacement values for non-detects are circled).

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

201 

Fish Hold Cleaning Effluent

 EPA expected effluent from the cleaning of fish holds to be fundamentally similar 

to fish hold effluent with two exceptions: 1) many vessels used a soap or disinfectant, 

which would not be expected to be present in the hold, and 2) cleaning fish holds brings 

in either potable water from the local municipality via a pierside hose (service water) or 

ambient water pumped from the surrounding waters. Table 3.4.3 presents summary 

statistics for fish hold cleaning effluent. Figures 3.4.6 and 3.4.7 show the detected results 

for total and dissolved metal concentrations, respectively, and Figures 3.4.8 and 3.4.9 

shows the PHQ values for total and dissolved concentrations, respectively, where 

applicable. 

Generally, average and maximum total and dissolved metals concentrations for 

fish hold cleaning were slightly lower than for fish hold effluent. These lower values 

could be due to any number of reasons: less contact time with the vessel for fish hold 

cleaning effluent, differences in source water (mechanically refrigerated and ice versus 

city tap water), less contact time (or none at all) with the seafood product or its residuals, 

etc. 

The lower concentrations of metals for fish hold cleaning effluent resulted in 

lower overall PHQ values for both total and dissolved forms, as well as a lower 

percentage of samples that exceed a PHQ of 1. Not surprisingly, the metals (dissolved 

copper, dissolved and total arsenic) identified as having high PHQs for fish hold effluent 

also exhibited higher PHQ values in fish hold cleaning effluent. Likewise, dissolved 

copper occurs in fish hold cleaning effluent at concentrations mostly above a PHQ value 

of one, and dissolved arsenic was found in two samples with PHQ values above one. 

Dissolved zinc was also found in several samples with PHQ values above one, the 

maximum being a PHQ value just below 10 (Figure 3.4.8). 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.4.3. Results of Fish Hold Cleaning Effluent Sample Analyses for Metals1

Metal Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Heavy and Other Metals 

Aluminum, Dissolved μg/L 9 9 100 780 880 74 74 760 950 100Aluminum, Total μg/L 9 9 100 1100 930 850 850 860 1500 170Arsenic, Dissolved μg/L 9 5 56 22 5.3 38 97 Arsenic, Total μg/L 9 5 56 35 8.7 64 150 Cadmium, Total μg/L 9 1 11 1.0 3.0 Chromium, Dissolved μg/L 9 1 11 1.5 3.4 Chromium, Total μg/L 9 3 33 4.6 5.4 23 Copper, Dissolved μg/L 9 8 89 34 12 8.6 32 180 Copper, Total μg/L 9 9 100 57 25 6.4 6.4 11 61 290 Lead, Dissolved μg/L 9 1 11 2.7 8.7 Lead, Total μg/L 9 4 44 19 37 79 Manganese, Dissolved μg/L 9 4 44 21 39 64 Manganese, Total μg/L 9 5 56 33 4.8 61 110 Selenium, Dissolved μg/L 9 1 11 6.0 14 Selenium, Total μg/L 9 2 22 7.4 7.0 18 Zinc, Dissolved μg/L 9 8 89 190 53 19 420 640 Zinc, Total μg/L 9 8 89 470 140 17 890 180

Cationic Metals 

Calcium, Dissolved μg/L 9 9 100 250000 270000 11000 11000 240000 300000 3200Calcium, Total μg/L 9 9 100 260000 280000 13000 13000 260000 310000 3200Magnesium, Dissolved μg/L 9 9 100 790000 860000 12000 12000 750000 990000 10000Magnesium, Total μg/L 9 9 100 780000 880000 13000 13000 710000 1000000 10000

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

202 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

203 

Figure 3.4.5. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Fish Hold Cleaning Effluent 

Aluminum

Arsenic

Cadmium

Chromium

Copper

Lead

Manganese

Selenium

Zinc

Total Metals

1

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1000

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

204 

Figure 3.4.6. Box and Dot Density Plot of Dissolved Metals Concentrations 

Measured in Samples of Fish Hold Cleaning Effluent 

Aluminum

Arsenic

Chromium

Copper

Lead

Manganese

Selenium

Zinc

Dissolved Metals

1

10

100

1000

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Aluminum

Arsenic

Cadmium

Chromium

Copper

Lead

Manganese

Selenium

Zinc

Total Metals

0.001

0.010

0.100

1.000

10.000

100.000

1000.000

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Figure 3.4.7. Box and Dot Density Plot of Potential Hazard Quotients for Total 

Metals in Samples of Fish Hold Cleaning Effluent 

(Note: Replacement values for non-detects are circled).

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

206 

Figure 3.4.8. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved 

Metals in Samples of Fish Hold Cleaning Effluent 

(Note: Replacement values for non-detects are circled).

Aluminum

Arsenic

Chromium

Copper

Lead

Manganese

Selenium

Zinc

Dissolved Metals

0.1

1.0

10.0

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.4.2 Classical Pollutants 

Table 3.4.4 presents analytical results for 14 classical pollutants detected in 

samples from fish hold effluent (all classical pollutants analyzed for in the study were 

detected). These detected results are also shown in Figure 3.4.9. 

Except for dissolved oxygen, other physical parameters measured (conductivity, 

pH, salinity, and temperature) did not have results that were likely to result in any impact 

on receiving water quality. Dissolved oxygen concentrations were low in several samples 

of fish hold effluent: hypoxic (< 2 mg/L) in three cases and marginal (<5 mg/L) in 19 

additional cases. These low oxygen conditions may be driven by the high BOD 

concentrations found in many of the fish holds. Effluent with low dissolved oxygen 

concentrations were also noted in the fish hold cleaning effluent, with six of nine samples 

(67 percent) having concentrations of less than 5 mg/L (see Table 3.4.5 and Figure 

3.4.10). 

EPA found BOD and COD to be highly elevated in fish hold effluent (Table 

3.4.4). BOD was measured in several samples in concentrations in the thousands of 

mg/L. High levels of BOD are almost certainly caused by the decay of the organic 

material associated with the seafood product. As shown in Figure 3.4.9, the majority of 

these concentrations are generally higher than those of raw sewage (which can range up 

to a few hundred mg/L), and almost all are higher than a wastewater treatment plant’s 

secondary treatment limit of 30 mg/L for BOD. The median value for BOD discharge 

was approximately 471 mg/L, indicating that BOD discharge from fish holds are 

abnormally elevated (see Figure 3.4.11). The highest BOD value of 5,130 mg/L 

approximates the concentrations found in sewage sludge (Metcalf and Eddy, 1979). 

These high levels of BOD in discharges could potentially pose environmental 

problems in certain circumstances. For example, high BOD concentrations in fish hold 

effluents are potentially ubiquitous, and discharges could result in impacts to receiving 

waters where there are numerous fishing vessels, poor flushing, or high levels of existing 

hypoxic (low oxygen) stress in the water body. In stratified waters with hypoxic or 

anoxic (no oxygen) conditions, the risk associated with elevated BOD is most likely to 

occur in deeper waters under a thermocline or picnocline. When using refrigerated 

seawater systems, fish hold effluent may be as saline (or more saline) than the 

surrounding water. Where it is also cooler than the surrounding water, the fish hold 

effluent would be more likely to sink to the bottom of the stratified water under the 

warmer water. This may deliver the BOD load to the deeper layers of the water body 

where oxygen levels are likely to be lower in eutrophic waters. In contrast, where ice is 

used to cool fish in the fish hold, the BOD load may be more likely to stay in the surface 

layers since fresh water is less dense than salt water. Thus, a low salinity fish hold 

207 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

effluent discharge may prevent the BOD loading from having as significant an impact to 

aquatic organisms in the receiving waters. 

The considerable variability in BOD concentrations from the 26 fish hold effluent 

samples may be due to how fish are kept. The average concentration of BOD is lowest 

for the lobster tank compared with the other fish hold types, which is logical since lobster 

tanks have continuously circulating ambient water with live seafood inside. Hence, the 

water is constantly being refreshed, while the seafood product generally has not begun 

the process of degrading or bleeding into the tank. There could be other differences in 

BOD concentrations based upon whether fish are kept on top of ice, in ice water slurry, or 

in refrigerated seawater. New England trawlers and Gulf Coast shrimp boats had several 

vessels with exceptionally high BOD concentrations. 

Whereas BOD measures oxygen demand from biodegradable material, COD 

measures oxygen demand for both biodegradable material and nonbiodegradable 

oxidizable material. Like BOD, COD discharge is elevated in fish hold effluent and fish 

hold cleaning effluent (Tables 3.4.4 and 3.4.5). Occasionally, these values are 

exceptionally high, which could potentially cause stress on a water body where there are 

many discharges from fish holds and where there may be low circulation or flushing or 

existing hypoxic or anoxic stress in the water body. 

Oil and grease as measured by HEM and SGT-HEM are generally discharged in 

low concentrations from fish hold effluent, with the vast majority of samples from both 

fish hold effluent and fish hold cleaning effluent having HEM and SGT-HEM being 

discharged in quantities below 5 mg/L. However, there are a few discharges where the 

concentrations exceed 15 mg/L. The highest of these values for either fish hold or fish 

hold cleaning effluent (the HEM concentration was approximately 28 mg/L - slightly less 

than twice the regulatory limit of 15 mg/L) are from the samples taken during a fish hold 

cleaning event while onboard a New England ground fishing vessel. These values 

demonstrate that while oil and grease discharges from fish holds sometimes occasionally 

occur at elevated concentrations, they were generally not observed at concentrations that 

are of particular concern. 

The concentrations of the classical pollutants EPA measured that are associated 

with sediment or cloudiness (i.e., TSS and turbidity) were roughly equivalent to 

concentrations observed in raw sewage effluent, but considerably lower than stormwater 

runoff from construction sites or highly urbanized streams. TSS was elevated in both fish 

hold effluent and fish hold cleaning effluent; however, concentrations were generally not 

sufficiently elevated to alone exceed water quality standards. Just under 90 percent of 

samples exceed the secondary treatment concentration of 30 mg/L for TSS (the value 

used to establish the PHQ benchmark), with a maximum concentration of 1,100 mg/L in 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

209 

a fish hold effluent sample. As with BOD, TSS appears to be more diluted in fish hold 

cleaning effluent than in fish hold effluent. While it did not test for volatile suspended 

solids (VSS) in this sampling program, EPA assumed that a significant percentage of the 

TSS concentration is directly caused by organic material related to the seafood product. 

Similar to TSS, turbidity concentrations were elevated in both fish hold effluent and fish 

hold cleaning effluent, and slightly more concentrated in fish hold effluent than in fish 

hold cleaning effluent. 

The concentrations of sulfide in fish hold and fish hold cleaning effluent were low 

in most samples, with most values falling below a reporting limit value of 0.01 mg/L. 

Sulfide was detected in only seven of 25 samples where the parameter was tested, and in 

only four of seven fish hold cleaning samples. However, a few samples had significantly 

elevated sulfide concentrations, including a maximum fish hold concentration of 0.16 

mg/L (PHQ value of 80) from fish hold discharges, and a maximum fish hold cleaning 

value of 0.48 mg/L (PHQ value of 240). These high sulfide values cannot be attributed to 

high background concentrations. A relatively higher percentage of detectable sulfide 

concentrations were noted in New England ground fishery trawlers compared with other 

areas (seven out of the 11 detections). EPA is unable to determine why the New England 

fishery vessels have higher concentrations of sulfide compared with vessels using other 

fishing platforms or from other areas; however, one possible explanation is that the New 

England fishery vessels are at sea for seven to 10 days, whereas Alaskan fishing vessels 

are off loaded once every one to two days. 

TRC was detected with some prevalence (roughly a third to two thirds of the 

samples for fish hold and fish hold cleaning effluent, respectively), with maximum 

concentrations of 0.3 mg/L (fish hold effluent) and 1.51 mg/L (fish hold cleaning 

effluent). PHQs for the fish hold and fish cleaning effluent ranged from one to 40 and one 

to 200, respectively (data not shown). Such high concentrations might be expected 

considering the source water (e.g., bag ice for keeping catch cold in fish holds) or use of 

chlorine bleach for cleaning and disinfection (fish hold cleaning effluent). In both cases, 

effluent volume is low relative to receiving waters for this volatile compound, and as 

such, EPA does not expect significant risk to human health or the environment. 

TOC was detected in all of the 25 of the fish hold effluent samples for which it 

was tested and all nine fish hold cleaning samples. Concentrations ranged from a low of 

1.8 mg/L to an extreme high of 2,200 mg/L (see Table 3.4.4). Background concentrations 

of TOC (i.e., from mechanically refrigerated water or ice) are much lower (in the range of 

2 to 19 mg/L) and do not appear to be a significant cause of the high TOC loads in the 

effluent. TOC levels are likely elevated by decay and residuals from the seafood product. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.4.4. Results of Fish Hold Effluent Sample Analyses for Classical Pollutants1

Parameter Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 9

Biochemical Oxygen Demand (BOD) mg/L 26 24 92 840 440 25 140 830 31Chemical Oxygen Demand (COD) mg/L 26 26 100 1500 940 52 340 660 1900 26Conductivity mS/cm 26 26 100 25 30 0.20 0.35 3.3 43 4Dissolved Oxygen mg/L 26 26 100 4.3 3.9 1.7 2.0 2.8 5.7 8Hexane Extractable Material (HEM) mg/L 26 18 69 3.2 1.5 2.9 6pH SU 26 26 100 7.0 6.8 6.0 6.3 6.5 7.5 7Salinity ppt 26 26 100 13 17 0.10 0.47 1.4 25 2Silica Gel Treated HEM (SGT-HEM) mg/L 26 15 58 3.4 0.98 2.2 3Sulfide mg/L 25 7 28 0.017 0.011 0.Temperature C 26 26 100 7.0 6.9 -0.16 0.098 3.0 9.5 1Total Organic Carbon (TOC) mg/L 25 25 100 290 140 1.8 8.3 48 260 9Total Residual Chlorine mg/L 26 10 38 0.096 0.13 0Total Suspended Solids (TSS) mg/L 26 26 100 210 130 10 29 71 190 6Turbidity NTU 26 26 100 96 63 9.0 16 25 120 3

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

210 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

211 

Table 3.4.5. Results of Fish Hold Cleaning Effluent Analyses for Classical Pollutants1

Parameter Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 9

Biochemical Oxygen Demand (BOD) mg/L 9 6 67 470 300 770 18Chemical Oxygen Demand (COD) mg/L 9 9 100 1100 960 490 490 530 1600 24Conductivity mS/cm 8 8 100 35 41 2.6 2.6 27 45 4Dissolved Oxygen mg/L 9 9 100 5.6 2.9 1.4 1.4 1.6 9.6 Hexane Extractable Material (HEM) mg/L 9 6 67 5.4 1.4 4.2 2pH SU 9 9 100 7.6 7.6 6.9 6.9 7.2 8.1 8Salinity ppt 9 9 100 48 24 1.3 1.3 19 27 2Silica Gel Treated HEM (SGT-HEM) mg/L 9 4 44 4.9 2.8 Sulfide mg/L 7 4 057 0.10 0.019 0.17 0Temperature C 9 9 100 9.2 8.2 4.7 4.7 5.7 12 Total Organic Carbon (TOC) mg/L 9 9 100 210 74 1.9 1.9 5.1 430 7Total Residual Chlorine mg/L 9 6 67 0.29 0.11 0.29 1Total Suspended Solids (TSS) mg/L 9 9 100 190 84 16 16 26 400 4Turbidity NTU 9 9 100 100 59 0.20 0.20 1.0 210 3

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

BOD (mg/l)

COD (mg/l)

Cond (mS/cm)

DO (mg/l)

HEM (mg/l)

SGT-H (mg/l)

Salin. (ppt)

Sulf. (mg/l)

TOC (mg/l)

TRC (mg/l)

TSS (mg/l)

Temp. (C)

Turb. (NTU)

pH (SU)

Classical Pollutants

0.01

0.10

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100.00

1000.00

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o

n

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nt Figure 3.4.9. Box and Dot Density Plot of Classical Pollutant Concentrations/Values 

Measured in Samples of Fish Hold Effluent 

212 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

BOD (mg/l)

COD (mg/l)

Cond (mS/cm)

DO (mg/l)

HEM (mg/l)

SGT-H (mg/l)

Salin. (ppt)

Sulf. (mg/l)

TOC (mg/l)

TRC (mg/l)

TSS (mg/l)

Temp. (C)

Turb. (NTU)

pH (SU)

Classical Pollutants

0.01

0.10

1.00

10.00

100.00

1000.00

C

o

n

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nt Figure 3.4.10. Box and Dot Density Plot of Classical Pollutant 

Concentrations/Values Measured in Samples of Fish Hold Cleaning Effluent 

213 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

BOD Concentrations in Wastewater Effluent

0

1000

2000

3000

4000

5000

Discharge Type

BOD Concentrations (mg/l)

Secondary Treatment Limit Raw Sewage

(Limit for Treated Sewage)

Fish Hold 

Effluent

Cleaning of 

Fish Hold

Raw Sewage Data Sources: Orford and Matusky (1959). Henry (1996). Medium value from Metcalf and Eddy (1979).

Figure 3.4.11. Comparison Between the BOD Secondary Treatment Limit from 

Sewage Treatment Facilities (30 mg/L), Average BOD Raw Sewage Concentrations, 

and BOD Concentrations from Fish Hold Effluent and Fish Hold Cleaning Effluent 

214 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.4.3 Pathogen Indicators (Microbiologicals) 

Sampling pathogen indicators from fish holds presented logistical challenges for 

the EPA sampling team. Many fishing vessels were sampled in locations remote from 

laboratories and the holding times of tests for these three pathogens (< 6 hours) prevented 

EPA from analyzing these samples from many of the sampling events. Nonetheless, EPA 

was able to test for E. coli and enterococci in seven fish hold effluent samples and for 

fecal coliform in 11 fish hold effluent samples. The results are summarized in Table 3.4.6 

(upper half of table) and shown graphically in Figure 3.4.12. 

What are Combined Sewer Overflows (CSOs) and Sanitary Sewer 

Overflows (SSOs)? 

Combined sewer systems are sewers that are designed to collect 

rainwater runoff, domestic sewage, and industrial wastewater in the 

same pipe. Most of the time, combined sewer systems transport all of 

their wastewater to a sewage treatment plant, where it is treated and 

then discharged to a water body. During periods of heavy rainfall or 

snowmelt, however, the wastewater volume in a combined sewer 

system can exceed the capacity of the sewer system or treatment 

plant. For this reason, combined sewer systems are designed to 

overflow occasionally and discharge excess wastewater directly to 

nearby streams, rivers, or other water bodies. These overflows, called 

combined sewer overflows (CSOs), contain not only stormwater but 

also untreated human and industrial waste, toxic materials, and debris. 

Properly designed, operated, and maintained sanitary sewer systems 

are meant to collect and transport all of the sewage that flows into 

them to a publicly owned treatment works (POTW). However, 

occasional unintentional discharges of raw sewage from municipal 

sanitary sewers occur in almost every system. These types of 

discharges are called sanitary sewer overflows (SSOs). SSOs have a 

variety of causes, including but not limited to severe weather, improper 

system operation and maintenance, and vandalism. EPA estimates 

that there are at least 40,000 SSOs each year. The untreated sewage 

from these overflows can contaminate our waters, causing serious 

water quality problems. 

Of these fish hold effluent samples, EPA detected bacteria concentrations above 

the most stringent screening benchmarks for one (of the seven) E. coli samples, four (of 

the seven) enterococci samples, and three (of the 11) fecal coliform samples. However, 

EPA strongly suspects that all of these exceedances were due primarily or exclusively 

due to background concentrations. For example, the fish hold effluent from a fishing 

vessel sampled in Gloucester, Massachusetts, exceeded all three stringent screening 

benchmarks for E. coli, enterococci, and fecal coliform. However, ambient water 

concentrations collected earlier in the day exceeded the concentrations in the later sample 

taken from the fish hold. The likely source of the pathogenic bacteria in this case was a 

combined sewer overflow (CSO) a few hundred feet above the location of the fishing 

vessel. The fishing 

vessel used ambient 

water to wash off its 

deck while 

unloading cargo 

(see section 

3.2.3.3). Some of 

this water likely 

made its way into 

the fish hold before 

EPA sampled the 

fish hold effluent 

again at the later 

time period; hence, 

in this case, EPA 

strongly doubts that 

the vessel was the 

source of the 

extremely high 

pathogen levels. 

215 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

216 

EPA encountered a similar situation while sampling a commercial fishing vessel 

in New Bedford, Massachusetts. The samples from the fish hold exceeded water quality 

criteria for enterococci (127 MPN/ 100 ml) and fecal coliform (125,000 CFU/ 100 ml). 

However, this vessel was sampled immediately adjacent to an SSO that contained raw 

fish waste and human sewage: the ambient water had enterococci concentrations of 4,342 

MPN/ 100 ml and fecal coliform concentrations of 6,500 CFU/ 100 ml. This vessel also 

used ambient water to hose off its deck, introducing the pathogenic bacteria to the fish 

hold. Note that for fecal coliform, this latter vessel’s fish hold effluent did appear to add 

to the high fecal coliform count in the sample. 

None of the concentrations of the three pathogens exceeded the most stringent 

NRWQC set for the pathogens in cases where the ambient concentrations were also 

below the stringent NRWQC. Although the results were based on this limited number of 

samples, EPA believes it is unlikely that there is an onboard source of these pathogenic 

bacteria in the fish hold. 

EPA was able to test the effluent from three separate fish holds from three vessels 

while they were being cleaned (see Table 3.4.6, lower half of table). Two of the fish hold 

cleaning effluent samples were from those vessels discussed above, where ambient water 

pathogen concentrations were impacted by the discharge from a CSO and an SSO. The 

third sample was from a vessel sampled in Sitka, Alaska. Similar to the fish hold effluent 

results from Massachusetts, EPA found that the concentrations of the effluent from the 

fish hold cleaning exceeded the NRWQC in one out of the three samples for E. coli, two 

out of the three samples for enterococci, and two out of three samples for fecal coliform. 

All the samples exceeding the most stringent screening benchmarks for the pathogens 

were from the vessels located in Massachusetts. Pathogen concentrations were below the 

detection limit for all three pathogens for the fish hold cleaning effluent from the vessel 

in Sitka. In all cases, background concentrations in the ambient water exceeded the fish 

hold cleaning effluent. Similar to what EPA observed with the fish hold effluent data, 

pathogen contamination in fish hold cleaning effluent from fishing vessels is not a likely 

source of pathogen contamination to receiving waters. Instead, EPA suspects that the 

pathogen contamination in these effluents might come from the vessel pumping ambient 

water with high levels of bacteria onboard. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.4.6. Results of Fish Hold and Fish Hold Cleaning Effluent Sample Analyses for Pathogen Indicato

Analyte2 Units3 No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Fish Hold 

E. coli by MPN MPN/100 ml 7 6 86 83 41 10 110 310 Enterococci by MPN MPN/100 ml 7 5 71 380 41 250 2200 Fecal Coliform by MF CFU/100 ml 11 6 55 11000 10 270 100000 

Fish Hold Cleaning 

E. Coli by MPN MPN/100 ml 3 2 67 200 52 550 550 Enterococci by MPN MPN/100 ml 3 2 67 1000 150 2800 2800 Fecal Coliform by MF CFU/100 ml 3 2 67 1900 250 5300 5300 

Notes:  (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in thi

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) MPN = Most Probable Number; MF = Membrane Filtration. (3) CFU = Colony Forming Units. (4) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

217 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

218 

Figure 3.4.12. Box and Dot Density Plot of Measured Pathogen Concentrations in 

Samples of Fish Hold Effluent

(Note: All values were subtantially influenced by background concentrations in the ambient water, and of 

the 25 sample results presented (seven results for E. coli, seven for enterococci, and 11 for fecal coliform), 

only two of the samples exceeded their background concentrations by more than 20 CFU/MPN 100 ml). 

100000

E. Coli

Enterococci

Fecal Colifo

Pathogen Indicators

10

100

1000

10000

C

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1

0

0

m

L
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.4.4 Nutrients 

Samples of fish hold effluent and fish hold cleaning were analyzed for four 

nutrients or nutrient-related parameters: ammonia nitrogen, nitrate/nitrite, TKN, and total 

phosphorus (see Table 3.4.7). The corresponding nutrient concentrations detected in fish 

hold and fish hold cleaning effluent samples are shown in Figures 3.4.13 and 3.4.14, 

respectively. 

Concentrations of total ammonia nitrogen (NH3-N), nitrate/nitrite nitrogen 

(NO3/NO2-N), TKN, and total phosphorus roughly compare to values of untreated raw 

sewage (see values in Table 3.4.8). The fish hold effluent had average ammonia 

concentrations of approximately 12 mg/L and the fish hold cleaning effluent had average 

concentrations of 16 mg/L, which compares roughly to weak sewage as reported by 

Metcalf and Eddy (1979) (see Table 3.4.8). However, there were several discharges in 

which the ammonia concentration substantially exceeded these concentrations, and these 

discharges could potentially result in acute toxic effects in the receiving water at and near 

the point of discharge (see Figure 3.4.13). These high values increase the average 

considerably (the median values for fish hold and fish hold cleaning effluent are 2.1 and 

4.8 mg/L, respectively). Most of the ammonia concentrations in samples collected from 

both fish hold and fish hold cleaning effluent exceed the PHQ screening benchmark of 

1.2 mg/L based on the freshwater chronic aquatic life criterion of 1.2 mg N/L, with the 

highest concentration resulting in a PHQ value of over 130. 

In contrast, average nitrate concentrations were near zero for both fish hold 

effluent (maximum concentration of 0.39 mg/L) and fish hold cleaning effluent 

(maximum concentration of max 0.53 mg/L). These concentrations are similar to those 

expected in raw sewage effluent no matter the strength of the sewage effluent (see Table 

3.4.8). However, the average total phosphorus concentrations of 13 mg/L for the fish hold 

effluent and 8.5 mg/L for fish hold cleaning effluent were similar to concentrations in 

medium to strong raw sewage (see Tables 3.4.7 and 3.4.8). 

TKN values averaged 110 mg/L for fish hold effluent and 59 mg/L for fish hold 

cleaning effluent. These TKN results31 can be roughly compared with total nitrogen 

results from Metcalf and Eddy (1979), showing that the nitrogen discharges are roughly 

equivalent to strong sewage. 

Protein, free amino acids, and nucleotides from fish and fish by-products are all 

potential sources of nitrogen. Inorganic phosphorus in the form of phosphate is a key 

 

31 TKN includes ammonia (NH3) and ammonium (NH4+), and organic nitrogen values. Total nitrogen 

includes ammonia (NH3) and ammonium (NH4+), organic nitrogen, and nitrate and nitrite values. Raw 

sewage tends to have very low nitrate and nitrite values. 

219 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

220 

element in DNA, RNA, and adenosine triphosphate (ATP) – key components present in 

the tissue and blood of any animal. 

 As shown in Figures 3.4.14 and 3.4.15, there is considerable variation exceeding 

two orders of magnitude in the concentrations of three of the four nutrient and nutrientrelated parameters. EPA observed that nutrient concentrations showed some relationship 

to the geographical location where the vessels operated. As shown in Figure 3.4.15, 

concentrations of ammonia, TKN, and TP from the Gulf Coast shrimp boats and the New 

England ground fishery trawlers appear to be higher than those from the fishing vessels 

sampled in Alaska or the New England lobster tank. In addition, compared to the lobster 

tank, whose water source is primarily flow-through water, all fishing vessel platforms 

appear to add nutrients to the effluent.
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.4.7. Results of Fish Hold (upper half) and Fish Hold Cleaning Effluent (lower half) Sample Analys

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Fish Hold 

Ammonia As Nitrogen (NH3-N) mg/L 26 25 96 12 2.1 0.64 1.1 6.7 Nitrate/Nitrite (NO3/NO2-N) mg/L 26 18 69 0.10 0.092 0.1Total Kjeldahl Nitrogen (TKN) mg/L 26 25 96 110 75 3.5 19 16Total Phosphorus mg/L 26 25 96 13 9.7 0.43 3.2 17 

Fish Hold Cleaning 

Ammonia As Nitrogen (NH3-N) mg/L 9 7 78 16 4.8 0.034 18 Nitrate/Nitrite (NO3/NO2-N) mg/L 9 8 89 0.24 0.27 0.070 0.3Total Kjeldahl Nitrogen (TKN) mg/L 9 6 67 59 40 14Total Phosphorus mg/L 9 7 78 8.5 11 0.025 17 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

Table 3.4.8. Raw Sewage Concentrations of Nutrients 

Concentration (expressed as mg/L) Constituent Strong Sewage Medium Sewage Weak Sewage 

Ammonia as N 50 25 12 Nitrate as N 0 0 0 Total Nitrogen 85 40 20 Total Phosphorus 15 8 4 Source: Metcalf and Eddy, 1979.

221 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

222 

Figure 3.4.13. Box and Dot Density Plot of Nutrient Concentrations Measured in 

Samples of Fish Hold Effluent

(Note: High maximum concentrations for certain samples for ammonia (160 mg N/L), total phosphorus (76 

mg/L), and TKN (338 mg/L) are evident). 

NH3-N

NO3/NO2-N

TKN

TP

Nutrients

0.1

1.0

10.0

100.0

C

o

n

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atio

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m( g

/

L)
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

223 

Figure 3.4.14. Box and Dot Density Plot of Nutrient Concentrations Measured in 

Samples of Fish Hold Cleaning Effluent 

(Note: For all parameters except ammonia, nutrient concentrations tend to be lower for fish hold cleaning 

effluent). 

NH3-N

NO3/NO2-N

TKN

TP

Nutrients

0.1

1.0

10.0

100.0

C

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Nutrient Concentrations by Fishing Platform/Type

0.01

0.1

1

10

100

1000

Concentration (mg/l)

Ammonia As Nitrogen

Total Kjeldahl Nitrogen

Total Phosphorus

Gillnetter Lobster 

Tank

Longliner Purse 

Seiner

Shrimp

Trawler

Tender N.E. 

Trawler

Troller

Figure 3.4.15. Comparison of Concentrations of Ammonia, TKN, and Total 

Phosphorus in Different Fishing Vessel Platforms to those in the Lobster Tank 

(which has a live catch and continuously circulating water) 

224 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

225 

3.2.4.5 Nonylphenols 

EPA analyzed three fish hold samples for nonylphenols. Short-chain nonylphenol 

ethoxylates (e.g., NP2EO, NP1EO) and NP were not detected in any of these samples. 

EPA expected this result because detergents should not be present when seafood catch is 

stored in the vessel’s fish hold compartment except for residual amounts from poor 

rinsing after cleaning. 

As expected, several long chain nonylphenol and octylphenol ethoxylates (NPEOs 

and OPEOs, respectively)) were detected in the fish hold cleaning samples collected from 

eight vessels (see Table 3.4.9). As with deck washdown water, the NPEOs with the 

longest ethoxylate chains were detected in approximately a third of the vessels, with 

concentrations increasing as ethoxylate chain is reduced (i.e., concentrations increasing 

from NP18EO to NP10EO). Of the vessels where long ethoxalate chain NPEOs were 

detected, only one of the three vessels had detectable concentrations of NPEOs 

representing the shortest chains (NP3EO through NP5EO); measured concentrations were 

low in the range of 12 to 32 μg/L, respectively. The OPEO with the longest ethoxylate 

chain (OP12EO) was detected in only one vessel, as were the lower ethoxylate chain 

OPEOs. For OPEOs, the concentrations showed the same general trend as the NPEOs 

with concentrations increasing as ethoxylate chain is reduced, although the 

concentrations of the shorter chain OPEOs were much lower than the shorter chain 

NPEOs. 

Total NPEO concentrations (from samples containing all 16 NPEO isomers) 

could be calculated for only two of the eight vessels whose fish hold cleaning effluent 

was sampled. The concentrations of total NPEOs ranged from 56 (a ground fishery 

trawler in Massachusetts) to 4,540 μg/L (another ground fishery trawler in 

Massachusetts). These results are shown graphically in Figure 3.4.16. 

While there is no NRWQC for the sum of NPEOs or OPEOs, as indicated in 

previous subsections, these compounds can degrade to NP in fresh and salt water (the 

saltwater chronic aquatic life criterion for NP is only 1.7 μg/L). EPA did not collect 

samples of background levels for analysis of total NPEOs, OPEOs, and NP from ambient 

or source water. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.4.9. Results of Fish Hold Cleaning Effluent Sample Analyses for Long-chain Nonylphenols1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75

Total Nonylphenol Polyethoxylates μg/L 8 2 25 620 4Nonylphenol octodecaethoxylate (NP18EO) μg/L 8 4 50 1.6 0.15 0.2Nonylphenol heptadecaethoxylate (NP17EO) μg/L 8 3 38 3.1 0.4Nonylphenol hexadecaethoxylate (NP16EO) μg/L 8 3 38 6.9 1.Nonylphenol pendecaethoxylate (NP15EO) μg/L 8 3 38 14 2.Nonylphenol tetradecaethoxylate (NP14EO) μg/L 8 2 25 25 2.Nonylphenol tridecaethoxylate (NP13EO) μg/L 8 2 25 39 3.Nonylphenol dodecaethoxylate (NP12EO) μg/L 8 2 25 56 5.Nonylphenol undecaethoxylate (NP11EO) μg/L 8 2 25 75 6.Nonylphenol decaethoxylate (NP10EO) μg/L 8 2 25 75 5.Nonylphenol nonaethoxylate (NP9EO) μg/L 8 2 25 73 4.Nonylphenol octaethoxylate (NP8EO) μg/L 8 2 25 74 4.Nonylphenol heptaethoxylate (NP7EO) μg/L 8 2 25 66 3.Nonylphenol hexaethoxylate (NP6EO) μg/L 8 2 25 51 1.Nonylphenol pentaethoxylate (NP5EO) μg/L 8 1 13 32 Nonylphenol tetraethoxylate (NP4EO) μg/L 8 1 13 21 Nonylphenol triethoxylate (NP3EO) μg/L 8 1 13 12 Octylphenol dodecaethoxylate (OP12EO) μg/L 8 1 13 2.8 Octylphenol undecaethoxylate (OP11EO) μg/L 8 1 13 2.7 Octylphenol decaethoxylate (OP10EO) μg/L 8 1 13 4.5 Octylphenol nonaethoxylate (OP9EO) μg/L 8 1 13 4.9 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

226 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

227 

Figure 3.4.16. Box and Dot Density Plot of Nonylphenol Concentrations Measured in 

Samples of Fish Hold Cleaning Effluent 

Nonylphenol parameters are identified as follows (nonylphenol and octylphenol ethoxylates in fish hold effluent 

were not detected): 

(1) Total Nonylphenol 

Polyethoxylates 

(2) Nonylphenol 

octodecaethoxylate (NP18EO) 

(3) Nonylphenol 

heptadecaethoxylate (NP17EO) 

(4) Nonylphenol 

hexadecaethoxylate (NP16EO) 

(5) Nonylphenol 

pendecaethoxylate (NP15EO) 

(6) Nonylphenol 

tetradecaethoxylate (NP14EO) 

(7) Nonylphenol 

tridecaethoxylate (NP13EO), 

(8) Nonylphenol 

dodecaethoxylate (NP12EO) 

(9) Nonylphenol 

undecaethoxylate (NP11EO) 

(10) Nonylphenol 

decaethoxylate (NP10EO) 

(11) Nonylphenol 

nonaethoxylate (NP9EO) 

(12) Nonylphenol 

octaethoxylate (NP8EO) 

(13) Nonylphenol 

heptaethoxylate (NP7EO) 

(14) Nonylphenol 

hexaethoxylate (NP6EO) 

(15) Nonylphenol 

pentaethoxylate (NP5EO) 

(16) Nonylphenol 

tetraethoxylate (NP4EO) 

(17) Nonylphenol triethoxylate 

(NP3EO) 

(18) Octylphenol 

dodecaethoxylate (OP12EO) 

(19) Octylphenol 

undecaethoxylate (OP11EO) 

(20) Octylphenol decaethoxylate 

(OP10EO) 

(21) Octylphenol 

nonaethoxylate (OP9EO)

1000.00

0 2 4 6 8 10 12 14 16 18 20 22

Nonylphenols

0.01

0.10

1.00

10.00

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o

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g/L)

100.00
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.4.6 Regional variation in Fish Hold Effluent Discharges 

Based on public comments received on EPA’s draft version of this report, EPA 

conducted a regional analysis of vessel fish hold discharges. EPA was able to conduct this 

analysis because there were 26 different hold discharges sampled. However, of the 26 fish hold 

discharges sampled, twenty were from Alaska, four were from New England, and only two were 

from the Gulf. A sample size of two is the absolute minimum number that can be used for any 

statistical comparisons, and caution must be exercised before drawing any general conclusions 

on the effects of fish hold discharge for an entire geographic region based on only two samples. 

Additionally, there is limited variation in the platforms sampled at New England and Gulf Coast 

locations. EPA cautions these results must be considered preliminary in nature and cannot be 

considered conclusive. The limitations of this analysis are also discussed in the following 

paragraphs. 

The potential regional 

differences in concentrations of fish 

hold discharges were examined for 

seven analytes (Total Copper, Total 

Zinc, Total Arsenic, Ammonia, Total 

Kjeldahl Nitrogen, Total Phosphorus, 

and Biological Oxygen Demand). 

Concentrations of each of these 

analytes were compared for the three 

regions in which vessels with fish hold 

discharge were sampled (Alaska, Gulf 

Coast, and New England). Mean 

analyte concentrations with 

corresponding standard deviations are 

shown for each of the regions in Table 

3.4.10. Based on this preliminary 

analysis, mean concentrations of all 

seven analytes were lower in the fish 

hold discharges from fishing vessels in 

Alaska compared to the concentrations 

discharged from fishing vessels in the 

Gulf Coast and New England. A 

preliminary statistical analysis 

(Welch’s t-tests accounting for 

unequal variance and unequal sample 

sizes – see accompanying text box for 

details) comparing each of these 

Regional Comparison of Fish Hold Discharge 

Concentrations 

A preliminary analysis was performed to assess the 

effects of geographic region on seven selected analytes 

listed in Table 3.4.10. Vessels were grouped into three 

broad geographic regions, and concentration differences 

between groups were evaluated using Welch’s t-tests 

accounting for unequal sample size and uneven variance. 

Prior to analysis, all concentrations were log transformed 

to stabilize sample variance. EPA performed t-test 

analyses with and without subtracting background analyte 

concentrations. The results were fundamentally similar. 

For each analyte, three comparisons were made (AlaskaGulf, Alaska-New England, Gulf-New England), at a 

Bonferroni adjusted significance level of .017 (.05/3), to 

account for the effect of multiple comparisons. 

Two additional analyses were performed to examine 

whether the observed regional differences could be 

explained by differences in fishing method (nets vs. no 

nets), or fish hold cooling method (ice vs. refrigerated 

seawater vs. both). These analyses also consisted of 

Welch’s t-tests for unequal sample size and unequal 

sample variance, and were conducted using log 

transformed concentrations after subtracting ambient 

concentration with appropriate Bonferroni adjusted 

significance levels to account for the effect of multiple 

comparisons. 

228 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

groups suggests that regional differences in the fish hold discharge concentrations for these 

seven analytes might be present, as concentrations from the two Gulf Coast vessels (shrimpers) 

were statistically significantly higher than concentrations from the twenty Alaska vessels for six 

of the seven analytes tested. The one exception was total arsenic, which did not differ 

significantly between any of the three regions. 

Although these results suggest the possibility of regional differences, they may also 

simply be a statistical artifact of: 1) a population of vessels that were both small in number and 

highly unevenly distributed across regions, 2) vessel type, 3) fish hold cooling method, 4) fishery 

type, or 5) some combination of the above. Both of the Gulf Coast vessels were shrimp trawlers, 

and three of the four New England vessels were ground fishery trawlers. Trawling vessels may 

also fish closer to the bottom of the water column, and could be expected to accumulate more 

organic matter along with their catch, which could potentially explain the higher concentrations 

of the analytes examined in this analysis. A fourth New England sample was taken from a 

lobster tank which consistently circulated ambient water. The twenty Alaska vessels consisted of 

five purse seiners, three gillnetters, three longliners, three tender vessels, and six trollers. The 

purse seiners and gillnetters spread nets, which may tend to pull fish or other material from 

closer to the bottom of the water column (though this is less likely in many deep waters off of 

Alaska). A second analysis was performed to determine whether the regional differences 

observed were an artifact of the distribution of vessel type; specifically, whether the vessel 

fishing method employed nets (trawlers, purse seiners, gillnetters), or some other method (lobster 

vessel, longliners, trollers). When the vessels were analyzed in two groups, those that do not use 

nets versus those that use nets, concentrations of total ammonia were statistically significantly 

higher, and concentrations of total arsenic and total copper were marginally (0.10<P<0.05) 

statistically significantly higher in vessels that use nets, perhaps because these vessels tend to 

fish closer to the bottom of the water column. It should be noted that both of the Gulf vessels 

and three of the four New England vessels were vessel types that employed nets, which may 

have influenced the results. When the same analysis was performed using only the Alaska 

vessels, only ammonia was marginally statistically significantly higher in the vessels that fish 

with nets, while zinc concentrations were statistically significantly higher in vessels that fish 

without nets. Again, small sample caveats apply to these and all other analyses described in this 

section. 

Finally, the effects of fish hold cooling method on fish hold discharge concentrations 

were examined. Of the twenty six vessels sampled, thirteen vessels used ice, ten used 

refrigerated water, two used both ice and refrigerated seawater, and one used recirculating 

ambient water. When vessels were examined as a function of cooling method, there were no 

statistically significant differences between any of the groups. This analysis was repeated for the 

subset of vessels from Alaska, and aside from (0.1<P<0.05) statistically significantly higher 

ammonia concentrations in Alaska vessels that chilled fish holds using refrigeration versus those 

that used ice, there were no statistically significant differences in fish hold discharges that could 

229 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

230 

be explained by fish hold cooling method. However, this result cannot be separated from the 

effects of fishing method (nets vs. no nets), as seven of seven vessels that cooled fish holds with 

refrigerated seawater also fished with nets, while nine of ten vessels that cooled with ice used 

fishing methods that did not involve nets. 

Although results of this analysis suggest differences in fish hold discharge concentrations 

are more pronounced between regions than between fishing method or fish hold cooling method, 

these results should be considered preliminary, and additional information will be required to 

draw any substantive conclusions regarding inter-region differences. Both the Gulf Coast and 

New England regions are represented by a small number of sample vessels. Not only is the Gulf 

Coast region represented by the minimum number of vessels with which to perform any 

statistical comparisons, the two vessels are similar with regard to vessel type and fish hold 

cooling method; therefore it cannot be assumed that the two sampled discharges are 

representative of the entire Gulf Coast fishery. While these analyses suggest the possibility of 

regional differences, the presence of true regional differences would require the sampling of a 

larger number of vessels from the Gulf and New England regions encompassing a broader, more 

evenly distributed number of vessels to account for the effects of vessel and discharge (ice or 

refrigerated water) type, as well as additional sampling of ambient receiving waters. 

Table 3.4.10. Means (and Standard Deviations) for Selected Analyte Concentrations, by 

Geographic Region. Units for All Analytes Expressed as μg/L, Except for BOD (mg/L). 

Mean Analyte Concentration Above Ambient (1 s.d.) Region Total Cu Total Zn Total As Ammonia TKN Total P BOD Vessel Type (no.) 

Alaska 53.7 253 4.79 2.72 75.4 8.40 416 Gillnetter (3) 

 (69.0) (223) (3.69) (2.74) (64.4) (6.35) (336) Longliner (3) 

 Purse Seiner (5) 

 Tender Vessel (3) 

 Troller (6) 

Gulf Coast 1640 446 186 19.0 397 24.7 3250 Shrimp Trawler (2) 

(30.7) (75.5) (233) (1.39) (201) (8.73) (499) 

New England 112 706 132 55.2 165 26.0 1720 Lobster Tank (1) 

 (146) (773) (170) (74.2) (245) (33.7) (2370) Ground Fishery Trawler (3) 

*As discussed in the text above, there are substantial limitations to this regional analysis which mean these results are preliminary in 

nature. Additional information is needed before making firm conclusions. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.4.7 Summary of the Characterization of Fish Hold Effluent and Fish Hold 

Cleaning Effluent 

Table 3.4.11 summarizes the specific analytes within fish hold and fish hold cleaning 

effluent water that may have the potential to pose risk to human health or the environment. 

EPA’s interpretation of a realized risk likely posed by these analytes, relative to pollutant 

loadings, background ambient and source water contaminant levels and characteristics, and other 

relevant information useful for this assessment, is presented in Chapter 5. 

Total iron was sampled for in only two vessels, but PHQs were between 5 and 10. 

Concentrations of dissolved copper exceeded NRWQC standards in all effluents sampled, with 

PHQs>10 in four of the vessels sampled. 

The concentrations of certain total and dissolved metals, as well as many of the other 

pollutants, measured in fish hold and fish hold cleaning effluent were elevated. Concentrations of 

total arsenic were detected in 16 of 26 samples, and when detected were measured at levels 

greatly exceeding its respective screening benchmark (i.e., NRWQC), resulting in PHQs of well 

over 100. Likewise, total copper concentrations, while only exceeding the NRWQC for human 

health of 1,300 μg/L in a few samples, were high in these few instances and might pose potential 

acute toxicity risk to aquatic life32. To a large degree, total aluminum, iron, and manganese 

concentrations could be explained by the respective metal concentrations in the surrounding 

waters. Arsenic and copper, however, most likely originated from the fish hold effluent. 

Concentrations of dissolved copper exceeded NRWQC standards in all effluents sampled, with 

PHQs well above 10 in four of the vessels sampled. Samples with concentrations of dissolved 

arsenic resulting in PHQs above 10 were limited to just two fishing vessels (a shrimper33 and a 

ground fishing trawler) with a third vessel having a PHQ of approximately 2. Approximately 2/3 

of the concentrations of dissolved zinc in fish hold effluent exceeded NRWQC benchmarks, but 

no concentrations of dissolved zinc exceeded a PHQ of 10, and most concentrations were below 

a PHQ of 3. Dissolved selenium was measured above reporting limits in only six discharges with 

PHQs>1 in all samples, and PHQs between 5 and 10 for two samples (including a shrimping 

vessel33). Total and dissolved metals concentrations were qualitatively similar in fish hold 

cleaning effluents, but, in general, concentrations in cleaning effluent were lower than in 

corresponding fish hold effluents. 

Several classical pollutants found in fish hold and fish hold cleaning effluent may have 

the potential to pose risk. A classical pollutant found in fish hold and fish hold cleaning effluent 

 

32 As discussed earlier in this chapter, total copper concentrations could pose potential risk to the aquatic 

environment because the human health criteria of 1,300 μg/L is significantly higher than the 3.1 μg/L benchmark 

used for dissolved copper based on the saltwater chronic ambient water quality criterion for the protection of aquatic 

life. When high levels of particulate copper are discharged, some of the particulate copper will likely convert to 

dissolved copper and be made bioavailable to aquatic life. 

33 See discussion in footnotes 29 and 30 and Section 3.2.4.1. 

231 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

232 

that poses one of the greatest potential risks to receiving waters is BOD, which was found at 

elevated concentrations in all sampled vessels and, in many instances, was higher than 

concentrations found in raw sewage (see Fig. 3.4.12). Concentrations of COD and TOC 

correlated with BOD concentrations and were similarly elevated in all fishing vessels. The high 

BOD in these samples likely contributed to the pervasively low dissolved oxygen levels in these 

samples. TSS and turbidity in fish hold and fish hold cleaning effluent are also equivalent to 

levels found in raw sewage, and concentrations of sulfide, particularly in samples from the New 

England ground fishery trawlers, exceeded the low PHQ screening benchmark (0.002 mg/L) for 

this classical pollutant. 

The other pollutants of potential concern in fish hold and fish hold cleaning effluent were 

the nutrient and nutrient-related parameters, particularly NH3-N, TKN, and TP, all of which 

were measured at concentrations similar to comparable concentrations typically measured in 

strong (raw) sewage samples. Again, mean concentrations of BOD, COD, TOC, NH3-N, TKN, 

and TP were highest in shrimping and trawling vessels. 

Aside from a select few samples, the high pathogen concentrations found in fish hold and 

fish hold cleaning samples likely did not stem from the effluent itself, but rather, from the 

excessively high concentrations measured in ambient background water contaminating the fish 

holds from the deck washdown process. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.4.11. Characterization of Fish Hold Effluent and Fish Hold Cleaning Effluent and Summary of An

Have the Potential to Pose Risk 

Analytes that May Have the Potential to Pose Risk in Fish Hold and Fish Hold C

Vessel Type (no. vessels)

Microbiologicals 

Volatile Organic Compounds 

Semivolatile Organic Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Sulfide 

Short-Chain Alkylphenol 

Ethoxylates and NP 

Long-Chain Alkylphenol 

Ethoxylates 

Fishing Vessels (31) enterococci, 

Fecal coliform

As,Cu, Zn Al,As, 

(Cu)2,Fe

x 

(1) Analytes are generally bolded when a large proportion of the samples have concentrations exceeding the NRWQC (e.g., 25 to 50 percent), when sev

two or three of five), when a few samples result in PHQs greatly exceeding the screening benchmark (i.e., 100s to 1,000s), in the case of oil and grease asamples exceed an existing regulatory limit by more than a factor of 2, or when concentrations of analytes are sufficiently high that they may have the pot

See text in Section 3.1.3 for a definition of PHQs and Table 3.1 for screening benchmarks used to calculate these values. 

(2) Only a few PHQs near or slightly exceeding 1, but concentrations (in excess of 1,000 μg/L) potentially acutely toxic to aquatic life, particularly to organ

233 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.5 Graywater

EPA sampled graywater from eight vessels: five tugboats, a shrimper, a water taxi and a 

recreational powerboat. The samples included graywater from sinks, dishwashers, and showers, 

as well as graywater samples from several mixed or unspecified sources. Graywater samples 

were analyzed for a range of pollutants including pathogen indicators, classical pollutants, 

nonylphenols, metals, and nutrients. The analytical results were intended to provide 

representative graywater pollutant concentrations over the range of normal vessel operations. 

Graywater volumes vary considerably depending on the class of vessel and its intended 

use, vessel size, the number of crew and passengers onboard, and the types of graywatergenerating activities onboard (e.g., galleys, sinks, showers, wash machines). Based on 

observations made during the sampling program and from discussions with crew members, EPA 

estimated that tugboats, some of which provide living quarters for three to five crew members, 

generate approximately 130 gpd of graywater. Water taxis, which carry a significantly larger 

number of crew and passengers, but with fewer graywater-generating activities, generate 

approximately 75 gpd of graywater. Graywater generation on commercial fishing boats might 

range from a few gpd to hundreds of gpd, depending on the length of the trip and the size of the 

crew. Due to the highly variable graywater generation volumes possible within vessel classes, 

EPA was unable to further define graywater generation rates. 

The Sink and Shower Facilities of a Tugboat 

234 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

235 

 

3.2.5.1 Pathogen Indicators (Microbiologicals) 

Graywater is generated from personal bathing, food preparation, and dish and clothes 

washing, so EPA expected that this vessel discharge category could contain high levels of 

pathogens. The analytical data for the pathogen indicator bacteria E. coli, enterococci and fecal 

coliform confirm this expectation as the levels of pathogens measured in graywater were by far 

the highest values measured in any of the vessel discharges. However, it should also be noted 

that for each of the pathogen indicators, a wide range of values were measured in the graywater 

samples. EPA also noted that source water (generally municipal water transferred onto the vessel 

(service water)) does not appear to account for any of the pathogen concentrations. 

The analytical results for pathogen indicators in the eight graywater samples are 

summarized in Table 3.5.1 and displayed in Figure 3.5.1. For each of these parameters, the 

highest levels (660,000 MPN/100 mL for E. coli, 240,000 MPN/100 mL for enterococci, and 

570,000 CFU/100 mL for fecal coliform) were measured in the mixed graywater sample from a 

tugboat. For comparison, EPA measured average levels of 292,000 MPN/100 mL for E. coli, 

8,920 MPN/100 mL for enterococci, and 36,000,000 CFU/100 mL for fecal coliform in untreated 

graywater, as reported in the 2008 Cruise Ship Discharge Assessment Report (USEPA, 2008). 

Typical fecal coliform concentrations in untreated domestic wastewater are 10,000 to 100,000 

MPN/100 mL34. The second highest concentration, of E. coli, was measured in a mixed 

(dish/shower) graywater sample, while the second highest concentrations, for enterococci and 

fecal coliform, were measured in a dishwashing sample. Samples of graywater from sinks and 

showers tended to have lower levels of the pathogen indicators. Pathogen indicators were not 

detected in graywater samples from the sink of one vessel, a water taxi. 

Figure 3.5.2 presents in box/scatter plots the PHQs for the three pathogen indicators in 

graywater. As this figure shows, the majority of the values measured for each of the pathogen 

indicators exceeded the water quality screening benchmarks, by up to four orders of magnitude 

(or more, in the case of fecal coliform). 

34 Note, as indicated above in Table 3.1 and elsewhere, units of MPN/100 ml for fecal coliform approximate similar 

units of CFU/100 ml; therefore, the two units of expression are appropriate for comparison here. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.5.1. Results of Graywater Sample Analyses for Pathogen Indicators1

Analyte Units2 No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% Ma

C

E. Coli MPN/100 ml 8 7 88 110000 16000 180 120000 660000 6Enterococci MPN/100 ml 8 7 88 40000 500 70 57000 240000 2Fecal Coliform CFU/100 ml 8 7 88 200000 270000 74 450000 570000 5Notes:  (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in thi

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) MPN = Most Probable Number; CFU = Colony Forming Units. (3) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

236 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

237 

Figure 3.5.1. Box and Dot Density Plot of Pathogen Indicator Values Measured in Samples 

of Graywater 

100000

E. Coli

Enterococci

Fecal colifo

Pathogen Indicators

1

10

100

1000

C

o

u

nt p

e

r

1

0

0

m

L

10000
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

238 

Figure 3.5.2. Box and Dot Density Plot of Potential Hazard Quotients for Pathogen 

Indicators Measured in Samples of Graywater 

(Note: Replacement values for non-detects are circled).

E. Coli

Enterococci

Fecal colifo

Pathogen Indicators

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

P

ote

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a

z

a

r

d

Q

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.5.2 Classical Pollutants 

Graywater samples were analyzed for 14 classical pollutants (see Table 3.5.2). Figure 

3.5.3 illustrates the variability of the concentrations/values measured for the classical pollutants 

in graywater. There was no one vessel or graywater source that tended to have the highest level 

of a majority of the classical pollutants, unlike the case for the pathogen indicators. The highest 

concentrations of oil and grease (100 mg/L HEM and 35.3 mg/L SGT-HEM) were measured in 

the sample of mixed dish/shower graywater on one tugboat; EPA speculates that the source of 

the oil and grease are primarily oils from cooking and other food sources discharged with the 

sink water. The highest levels of TSS (99 mg/L) and turbidity (128 NTU) were measured in the 

dishwashing graywater from a second tugboat. The highest sulfide concentration (1.45 mg/L) 

was measured in a shower graywater sample from a third tugboat. The highest measured 

concentrations of BOD (1200 mg/L), COD (4,040 mg/L), and TOC (440 mg/L) were measured 

in the sample of shower graywater from the recreational powerboat. 

Many of the classical pollutants that were elevated in the graywater samples likely reflect 

the washing and bathing activities that generate graywater discharges. For example, sulfide35 is a 

parameter that is commonly elevated in water distribution systems, especially on the hot water 

side. Sulfur-reducing bacteria, which use sulfur as an energy source, are the primary producers of 

large quantities of hydrogen sulfide. Sulfur-reducing bacteria can live in plumbing systems and 

hot water heaters. A second example is the high concentration of BOD measured in graywater 

samples (mentioned above), which reflects the BOD generated onboard the vessels sampled and 

not from the service water used by that vessel.

Figure 3.5.4 presents the PHQs for classical pollutants in graywater in box/scatter plots. 

As this figure shows, the PHQ threshold of 1 was exceeded for sulfide, TRC (detected in only 

one sample (0.11 mg/L) above the reporting limit of 0.0075 mg/L for a PHQ of 15), BOD, oil 

and grease (measured as HEM), and TSS. The highest PHQs were calculated for sulfide at 367 

and BOD at 40. All of the graywater samples exceeded the 30 mg/L benchmark for BOD, and all 

five of the detected concentrations of sulfide exceeded the 0.002 mg/L benchmark. 

The source of water used on the sampled vessels was, in all cases, potable freshwater 

bunkered in port (service water). Therefore, EPA did not consider it appropriate to compare the 

 

35 Although sulfide (S 2-) is the analyte, hydrogen sulfide (H2S) is the nonpriority pollutant for which a NRWQC has been 

established. Sulfides are commonly found as either hydrogen sulfide or hydrosulfide (HS-

). EPA conservatively assumes that all of 

the sulfide is in the form of hydrogen sulfide (H2S) is the form that is toxic to fish. However, the proportion of each depends on the 

pH of the water. At pH 9 about 99 percent of the sulfide is in the form of HS-

; at pH 7 the sulfide is equally divided between HS- and 

H2S; and at pH 5 about 99 percent of the sulfide is present as H2S. Unless heavily polluted, freshwater rivers typically tend to have 

a pH which ranges from about 4.5 to about 7, marine environments have an average pH of around 8.1 (seawater is more basic 

freshwater), while estuaries may have a pH between that of freshwater and seawater (approximately 5 to 8) dependent upon salinity 

and other factors. Hence, the use of sulfide (S 2-) as the analyte to detect for the presence of hydrogen sulfide (H2S) is more 

conservative in marine and estuarine environments than in freshwater ones, but is a reasonable analyte to use due to variation 

found in different aquatic ecosystems. 

239 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

240 

concentrations of classical pollutants in graywater to ambient water body concentrations; rather, 

EPA compared the concentrations of classical pollutants to those found in the service water. 

None of the conventional parameters discussed here were consistently detected in service water. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.5.2. Results of Graywater Sample Analyses for Classical Pollutants1

Analyte Units No. samples No. detected Detected proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75

Biochemical Oxygen Demand (BOD) mg/L 8 8 100 430 260 99 99 110 85Chemical Oxygen Demand (COD) mg/L 8 8 100 1000 440 180 180 270 17Conductivity mS/cm 7 7 100 0.43 0.41 0.22 0.22 0.30 0.5Dissolved Oxygen mg/L 7 7 100 7.4 7.1 6.0 6.0 6.3 8.Hexane Extractable Material (HEM) mg/L 8 8 100 39 29 9.4 9.4 14 6pH SU 8 8 100 7.4 7.2 6.1 6.1 6.7 8.Salinity ppt 6 6 100 0.25 0.20 0.10 0.10 0.18 0.4Silica Gel Treated HEM (SGTHEM) mg/L 8 6 75 8.1 1.5 0.33 9.Sulfide mg/L 8 5 63 0.11 0.017 0.0 0.0Temperature C 8 8 100 27 27 21 21 24 2Total Organic Carbon (TOC) mg/L 7 7 100 140 83 27 27 66 16Total Residual Chlorine mg/L 8 6 75 0.12 0.020 Total Suspended Solids (TSS) mg/L 8 8 100 52 58 14 14 37 6Turbidity NTU 8 8 100 74 89 40 40 45 11Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

241 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

242 

Figure 3.5.3. Box and Dot Density Plot of Classical Pollutant Concentrations/Values 

Measured in Samples of Graywater 

BOD (mg/l)

COD (mg/l)

Cond (mS/cm)

DO (mg/l)

HEM (mg/l)

SGT-H (mg/l)

Salin. (ppt)

Sulf. (mg/l)

TOC (mg/l)

TRC (mg/l)

TSS (mg/l)

Temp. (C)

Turb. (NTU)

pH (SU)

Classical Pollutants

0.001

0.010

0.100

1.000

10.000

100.000

1000.000

C

o

n

c

e

ntr

atio

n

o

r

A

m

o

u

nt
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

243 

Figure 3.5.4. Box and Dot Density Plot of Potential Hazard Quotients for Classical 

Pollutants in Samples of Graywater 

(Note: Replacement values for non-detects are circled).

BOD (mg/l)

COD (mg/l)

Cond (mS/cm)

DO (mg/l)

HEM (mg/l)

SGT-H (mg/l)

Salin. (ppt)

Sulf. (mg/l)

TOC (mg/l)

TRC (mg/l)

TSS (mg/l)

Temp. (C)

Turb. (NTU)

pH (SU)

Classical Pollutants

0.1

1.0

10.0

100.0

P

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a

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a

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

244 

3.2.5.3 Nonylphenols 

 Long- and short-chain nonylphenol and octylphenol ethoxylates and NP were expected in 

graywater discharges given their use in soaps for hand and body washing and in liquid detergents 

for dish washing. EPA anticipated that the long-chain alkylphenol ethoxylates would be present 

in all graywater samples where detergents were used for cleaning, while the short-chain 

ethoxylates (and possibly NP) would be present if detergents were used for cleaning and there 

was a graywater holding tank that provided the additional residence time necessary for biological 

activity to degrade the NPEOs and OPEOs. 

Graywater samples were analyzed for 34 long- and short-chain nonylphenol and 

octylphenol ethoxylates, including 28 NPEOs and OPEOs, bisphenol A, and total nonylphenol 

(NP). Of these parameters, 25 were detected in one or more samples (see Table 3.5.3). Average 

concentrations for NP18EO-NP3EO and OP12EO-OP6EO ranged from approximately 0.1 to 10 

μg/L. The average concentrations of total nonylphenol polyethoxylates (sum of NPEO isomers) 

and total octylphenol polyethoxylates (sum of OPEO isomers) were 66 and 63 μg/L, 

respectively. All of the NPEOs were detected in the graywater sample from the sink of one of the 

tugboats and the graywater sampled from the shower on the recreational powerboat. All of the 

OPEOs were detected in the graywater sampled from the shower on the recreational powerboat. 

NPEOs and OPEOs were also occasionally detected in graywater samples from three of the other 

vessels. 

 EPA did not calculate any PHQs for the nonylphenol parameters measured in graywater. 

The only screening benchmark available was the saltwater chronic NRWQC for NP (1.7 μg/L). 

There were no analytical results for NP to compare to this screening benchmark, and no 

NRWQC exist for the other nonylphenol parameters (individual or total long- and short-chain 

NPEOs and OPEOs). None of the long- or short-chain nonylphenol or octylphenol ethoxylates or 

NP were detected in the ambient water surrounding these vessels. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.5.3. Results of Graywater Sample Analyses for Nonylphenols (only long-chain NPEOs and OPEOs 

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 7

Total Nonylphenol Polyethoxylates μg/L 8 2 25 66 Nonylphenol octodecaethoxylate (NP18EO) μg/L 8 2 25 0.084 0.Nonylphenol heptadecaethoxylate (NP17EO) μg/L 8 3 38 0.31 0Nonylphenol hexadecaethoxylate (NP16EO) μg/L 8 3 38 0.59 0Nonylphenol pendecaethoxylate (NP15EO) μg/L 8 3 38 1.1 0Nonylphenol tetradecaethoxylate (NP14EO) μg/L 8 3 38 2.2 0Nonylphenol tridecaethoxylate (NP13EO) μg/L 8 3 38 3.5 1Nonylphenol dodecaethoxylate (NP12EO) μg/L 8 3 38 5.4 3Nonylphenol undecaethoxylate (NP11EO) μg/L 8 3 38 7.0 4Nonylphenol decaethoxylate (NP10EO) μg/L 8 2 25 6.7 2Nonylphenol nonaethoxylate (NP9EO) μg/L 8 2 25 7.3 2Nonylphenol octaethoxylate (NP8EO) μg/L 8 2 25 7.9 1Nonylphenol heptaethoxylate (NP7EO) μg/L 8 1 13 7.8 Nonylphenol hexaethoxylate (NP6EO) μg/L 8 1 13 7.3 Nonylphenol pentaethoxylate (NP5EO) μg/L 8 2 25 5.8 1Nonylphenol tetraethoxylate (NP4EO) μg/L 8 2 25 4.7 1Nonylphenol triethoxylate (NP3EO) μg/L 8 1 13 2.8 Total Octylphenol Polyethoxylates μg/L 8 1 13 63 Octylphenol dodecaethoxylate (OP12EO) μg/L 8 4 50 1.5 0.22 3Octylphenol undecaethoxylate (OP11EO) μg/L 8 2 25 2.0 3Octylphenol decaethoxylate (OP10EO) μg/L 8 2 25 3.5 4Octylphenol nonaethoxylate (OP9EO) μg/L 8 1 13 3.3 Octylphenol octaethoxylate (OP8EO) μg/L 8 1 13 7.6 Octylphenol heptaethoxylate (OP7EO) μg/L 8 1 13 10 Octylphenol hexaethoxylate (OP6EO) μg/L 8 1 13 10 Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

245 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.5.4 Metals 

Graywater samples were analyzed for dissolved (filtered) and total concentrations of 

metals. The analytical results are summarized in Table 3.5.4 for the dissolved metals and Table 

3.5.5 for the total metals that were detected in at least one graywater sample. The following 

metals were detected in all of the graywater samples: 

 Dissolved and total aluminum 

 Total barium 

 Dissolved and total calcium 

 Dissolved and total copper 

 Dissolved and total manganese 

 Dissolved and total potassium 

 Dissolved and total sodium 

 Dissolved and total zinc. 

Concentrations of other metals were measured in 50 percent or more of the graywater samples: 

 Dissolved barium 

 Total chromium 

 Total iron 

 Total lead 

 Dissolved and total magnesium 

 Dissolved and total nickel 

 Dissolved and total selenium 

 Total vanadium. 

 Figures 3.5.5 and 3.5.6 present the ranges of concentrations measured for dissolved and 

total metals in the graywater samples. The plots show that dissolved and total metals 

concentrations range over five orders of magnitude. Calcium, magnesium, potassium and 

sodium, which are the major cations present in seawater, were the dissolved metals measured at 

the highest concentrations. Dissolved aluminum, copper, and zinc were also measured at 

relatively high concentrations (greater than 100 μg/L) in most graywater samples. For these 

dissolved metals, service water samples contained up to 80 percent of the graywater 

concentration for aluminum, up to 100 percent for copper, and up to 170 percent for zinc. 

Although the comparison of service water and graywater concentrations suggests that service 

water might be the source of these metals in some of the graywater samples, this was not always 

the case. In fact, service water concentrations tended to be low in the samples that corresponded 

to the highest metals concentrations in graywater. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

247 

 Total concentrations for each metal were generally similar to or somewhat higher than 

the dissolved concentrations. Aside from the major seawater cations, concentrations of total 

metals in the graywater samples were highest for aluminum (912 μg/L), copper (440 μg/L), iron 

(458 μg/L), and zinc (3,470 μg/L). For these total metals, EPA found that service water samples 

contained up to 74 percent of the graywater concentration for aluminum, up to 115 percent for 

copper, up to 175 percent for iron, and up to 32 percent for zinc. As was the case for dissolved 

metals, comparing the service water and graywater concentrations suggests that service water 

might be the source of these total metals in some, but not all, of the graywater samples. 

 To quantify the relationship between dissolved and total metals concentrations, EPA 

calculated the average dissolved fraction (fd) of each metal in the graywater samples. The metals 

in graywater discharges with the highest average dissolved fractions (fd > 90 percent) included 

arsenic, calcium, magnesium, nickel, potassium, and sodium. For all of the other metals where 

dissolved fractions could be calculated (aluminum, barium, chromium, copper, iron, lead, 

manganese, selenium, vanadium, and zinc), the average values were in the intermediate (90 

percent > fd > 50 percent) range. 

The plots in Figures 3.5.7 and 3.5.8 display the distribution of PHQs based on the 

screening benchmark for each of the dissolved and total metals. For dissolved metals, copper and 

zinc concentrations consistently exceed the screening benchmarks; the maximum PHQs for 

copper and zinc were 90 and 18.5, respectively. For total metals, the measured concentrations of 

aluminum consistently exceeded the screening benchmarks. PHQs for total aluminum varied 

from 0.6 to 10.5. The PHQs based on measured concentrations of total arsenic were 160 and 110 

(arsenic was detected in only two of eight graywater samples, one of which may have an 

elevated measured concentration due to positive interference(see discussion on page 74 for more 

information); these high values reflect the very low NRWQC (0.018 μg/L; human health for the 

consumption of water + organism) for this carcinogen. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.5.4. Results of Graywater Sample Analyses for Dissolved Metals1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% Ma

C

Heavy and Other Metals 

Aluminum μg/L 7 7 100 190 160 24 24 86 300 460 Arsenic μg/L 8 2 25 1.9 1.1 4.5 Barium μg/L 3 2 67 26 27 45 45 Chromium μg/L 8 2 25 1.4 1.4 2.2 Copper μg/L 8 8 100 55 17 5.3 5.3 7.6 60 280 Iron μg/L 3 1 33 83 150 150 Lead μg/L 8 4 50 2.5 1.1 4.2 6.0 Manganese μg/L 8 8 100 17 8.8 4.7 4.7 6.4 35 42 Nickel μg/L 8 4 50 5.5 2.1 70 9.8 Selenium μg/L 8 1 13 3.5 1.4 Thallium μg/L 3 1 33 0.80 1.4 1.4 Vanadium μg/L 3 1 33 0.73 1.2 1.2 Zinc μg/L 8 8 100 400 240 70 70 80 610 1500 

Cationic Metals 

Calcium μg/L 8 8 100 34000 33000 1800 1800 25000 36000 81000 8Magnesium μg/L 8 7 88 9400 11000 6600 13000 18000 1Potassium μg/L 3 3 100 5500 5700 4100 4100 4100 6700 6700 Sodium μg/L 3 3 100 79000 48000 31000 31000 31000 160000 160000 1Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

248 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

249 

Table 3.5.5. Results of Graywater Sample Analyses for Total Metals1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Heavy and Other Metals 

Aluminum μg/L 8 8 100 380 420 50 50 190 540 910 Arsenic μg/L 8 2 25 2.0 1.5 2.9Barium μg/L 3 3 100 29 28 7.4 7.4 7.4 51 51 Cadmium μg/L 8 1 13 0.82 2.0 Chromium μg/L 8 4 50 2.5 2.2 4.2 4.9 Copper μg/L 8 8 100 100 71 10 10 14 140 440 Iron μg/L 3 2 67 220 150 460 460 Lead μg/L 8 5 63 7.6 1.7 5.8 43 Manganese μg/L 8 8 100 22 13 7.3 7.3 8.9 41 51 Nickel μg/L 8 4 50 5.9 2.6 8.6 10 Selenium μg/L 8 1 13 3.8 1.7 Vanadium μg/L 3 2 67 1.7 1.9 2.6 2.6 Zinc μg/L 8 8 100 890 270 54 54 130 2000 350

Cationic Metals 

Calcium μg/L 8 8 100 35000 36000 1900 1900 26000 37000 8200Magnesium μg/L 8 7 88 9700 11000 6500 13000 1800Potassium μg/L 3 3 100 5500 6400 3400 3400 340 6600 660Sodium μg/L 3 3 100 81000 47000 36000 36000 36000 160000 1600Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm(3) EPA suspects that this measured concentration may be elevated due to positive interference, see Section 3.1.3. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

250 

Figure 3.5.5. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Graywater 

Aluminum

Arsenic

Barium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Selenium

Thallium

Vanadium

Zinc

Dissolved Metals

1

10

100

1000

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

251 

Figure 3.5.6. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Graywater

Aluminum

Arsenic

Barium

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Selenium

Vanadium

Zinc

Total Metals

1

10

100

1000

C

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

252 

Figure 3.5.7. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals 

in Samples of Graywater 

(Note: Replacement values for non-detects are circled). 

100.00

Aluminum

Arsenic

Barium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Selenium

Thallium

Vanadium

Zinc

Dissolved Metals

0.01

0.10

1.00

10.00

P

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

253 

Figure 3.5.8. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Graywater 

(Note: Replacement values for non-detects are circled).

100.00

Aluminum

Arsenic

Barium

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Selenium

Vanadium

Zinc

Total Metals

0.01

0.10

1.00

P

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10.00
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

254 

3.2.5.5 Nutrients 

Graywater samples were analyzed for four nutrient and nutrient-related parameters: 

ammonia nitrogen, nitrate/nitrite, TKN, and total phosphorus (see Table 3.5.6). The nutrient 

concentrations measured in graywater samples are displayed in Figure 3.5.9. The highest nutrient 

concentrations measured in graywater were: 4.5 mg/L (ammonia nitrogen), 2.4 mg/L 

(nitrate/nitrite), 45 mg/L (TKN), and 3.4 mg/L (total phosphorus); all of these values were 

measured in a single sample of shower graywater from a tugboat. A likely source of the 

phosphorus in graywater could be phosphate detergents, although both phosphorus and nitrogen 

parameters also reflect food and possibly other wastes. Of these maximum nutrient 

concentrations, only TKN was high enough to fall within the range of concentrations typical of 

untreated domestic wastewater (20 to 85 mg/L; Metcalf and Eddy, 1979). Although each of these 

nutrients was occasionally detected in service water, only nitrate/nitrite was present in service 

water at concentrations high enough to be comparable with those in graywater. 

Figure 3.5.10 presents the PHQs calculated for the nutrients. As shown in this figure, 

total phosphorus PHQs ranged from 4.2 to 34 because concentrations in graywater consistently 

exceeded the screening benchmark. Graywater samples from three tugboats also had PHQs of 

greater than 1 because the concentrations for ammonia nitrogen exceeded the screening 

benchmark.
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.5.6. Results of Graywater Sample Analyses for Nutrients1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 90% 

Ammonia As Nitrogen (NH3-N) mg/L 8 8 100 1.3 0.75 0.19 0.19 0.22 1.8 4.5 Nitrate/Nitrite (NO3/NO2-N) mg/L 8 7 88 1.6 1.9 0.90 2.3 2.4 Total Kjeldahl Nitrogen (TKN) mg/L 8 8 100 10 6.7 2.2 2.2 3.8 7.7 45 Total Phosphorus mg/L 8 8 100 1.4 1.2 0.42 0.42 0.62 2.2 3.4 Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

255 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

256 

Figure 3.5.9. Box and Dot Density Plot of Nutrient Concentrations Measured in Samples of 

Graywater 

NH3-N

NO3/NO2-N

TKN

TP

Nutrients

0.01

0.10

1.00

10.00

C

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

257 

Figure 3.5.10. Box and Dot Density Plot of Potential Hazard Quotients for Nutrients in 

Samples of Graywater 

100.00

NH3-N

NO3/NO2-N

TKN

TP

Nutrients

0.01

0.10

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.5.6 Summary of the Characterization of Graywater Effluent Analyses 

Table 3.5.7 summarizes the specific analytes in graywater effluent that may have the 

potential to pose risk to human health or the environment. EPA’s interpretation of the realized 

risk that may be posed by these analytes, relative to pollutant loadings, background ambient and 

source water contaminant levels and characteristics, and other relevant information useful for 

this assessment, is presented in Chapter 5. 

Pathogens were found at higher concentrations in graywater effluent than in any other 

type of pollutant. The highest concentrations of all three pathogen groups (fecal coliforms, 

enterococci, and E. coli) were found in the effluent of one of the five tugboats sampled, but were 

found at high concentrations in all five sampled tugboats. For all eight vessels sampled, the 

majority of PHQs for all three pathogen groups were greater than 1 (PHQs for all fecal coliform 

samples were greater than 10), and, in many cases, were between 100 and 10,000. The fecal 

coliform concentrations most often exceeded the water quality benchmarks, followed by E. coli

and enterococci concentrations, in that order. Pathogens were not detected in the one water taxi. 

BOD was the pollutant with the next highest concentrations that exceeded water quality 

benchmarks, with PHQs>1 in all eight vessels and PHQ values exceeding 9 for five of the 

vessels. The highest BOD concentrations were found from the recreational powerboat (PHQ = 

40). Concentrations of COD and TOC were positively correlated to BOD concentrations and 

were found at high levels in all eight vessels. Sulfide was detected in five of the eight vessels and 

exceeded benchmark concentrations in all five instances (PHQs of up to 367). Sulfides were 

detected in graywater from all vessels sampled, and elevated in the five tugboat discharges, with 

PHQs ranging from 5-367. TSS and oil and grease (measured as HEM) concentrations were also 

slightly elevated, particularly in tugboats. The highest HEM concentration (100 mg/L) was 

observed in the graywater discharge from a tugboat. SGT-HEM was detected in six of eight 

vessels, but only one sample had a PHQ greater than 2. 

Total nonylphenol polyethoxylates (sum of isomers from NP3EO to NP18EO) were 

notable only in one tugboat and the recreational boat. Total NPEOs was highest in the graywater 

sample collected from the recreational powerboat. No short-chain alkylphenol ethoxylates 

(NP1EO,NP2EO or OP1EO or OP2EO) or bisphenol A were detected in any of the graywater 

samples. Likewise, no NP was detected, so no comparisons could be made to the screening 

benchmark. 

Among the nutrients sampled, total phosphorus concentrations exceeded the benchmark 

of 0.10 mg/L in all vessels sampled, with PHQs ranging from 4.2 to 34. 

Concentrations of dissolved copper and zinc regularly exceeded NRWQC benchmarks, 

with a maximum PHQ of 90 for dissolved copper and 18 for dissolved zinc. The median 

concentration for dissolved aluminum was 160 μg/L, though no benchmark exists. Service water 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

259 

 

concentrations of dissolved aluminum, copper, and zinc were moderately influential, but only in 

the graywater samples with the lowest measured concentrations. Total arsenic was detected in 

the shrimping36 and recreational vessel where concentrations exceeded NRWQC benchmarks 

(PHQ values were 111 and 161, respectively). Total aluminum concentrations exceeded 

NRWQC benchmarks in seven of the eight vessels, with one vessel exceeding a PHQ of 10. 

36 See Section 3.2.5.4and footnote 3 in Table 3.5.5. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.5.7. Characterization of Graywater Effluent and Summary of Analytes that May Have the Potenti(1) Analytes are generally bolded when a large proportion of the samples have concentrations exceeding the NRWQC (e.g., 25 to 50 percent), when sev

two or three of five), when a few samples result in PHQs greatly exceeding the screening benchmark (i.e., 100s to 1,000s), in the case of oil and grease asamples exceed an existing regulatory limit by more than a factor of 2, or when concentrations of analytes are sufficiently high that they may have the pot

See text in Section 3.1.3 for a definition of PHQs and Table 3.1 for screening benchmarks used to calculate these values. 

Analytes that May Have the Potential to Pose Risk in Graywater Effluent and Ves

Vessel Type (no. vessels)

Microbiologicals 

Volatile Organic Compounds 

Semivolatile Organic Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Sulfide 

Short-Chain Alkylphenol 

Ethoxylates or NPs 

Long-Chain Alkylphenol 

Ethoxylates 

Tugboat (5) fecal coliform 

enterococci 

E. coli

Al, Cu, Zn Al x x x 

Shrimping Vessel (1) fecal coliform 

enterococci 

E. coli

Cu, Zn As, Al 

Water Taxi (1) Cu, Zn Al 

Recreational (1) fecal coliform 

enterococi 

E. coli

Cu, Zn As, Al x x 

(2) EPA notes that the conclusion of potential risk is drawn from a small sample size, in some cases a single vessel, for certain discharges sampled from 

results in the tables to provide a concise summary of the data collected in the study, but strongly cautions the reader that these conclusions, where there class, should be considered preliminary and might not necessarily represent pollutant concentrations from these discharges from other vessels in this cla

260 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6 Engine Effluent 

Vessel engines are primarily used for two purposes: propulsion and electrical generation. 

Engines used for vessel propulsion can be either outboard or inboard engines. Vessels that 

require significant lighting or have electrical equipment such as appliances and/or electric motors 

are likely equipped with engines used for electrical generation. 

Engine cooling systems include direct cooling, indirect cooling, and keel cooling. Direct 

and indirect cooling systems discharge wastewater, while keel cooling systems are zero 

discharge. Some engines with direct and indirect cooling systems also use water to cool and quiet 

their exhaust, referred to as engine wet exhaust. These engines inject spent cooling water from 

the engine into the exhaust stream, so that the cooling water directly contacts the engine exhaust. 

Possible constituents of concern in engine effluent include the following: thermal loading; metals 

from the discharge contacting the exhaust system, from erosion of moving engine components 

(e.g., pistons), or from trace constituents of the fuel; and oil and grease and organic compounds 

as constituents of fuel or possible products of incomplete fuel combustion. 

The volume of engine cooling water discharged depends on the type of engine and power 

level of operation. Vessels with outboard propulsion engines discharge between 1 and 2 gpm of 

raw cooling water per engine based on observations made during the sampling program. The 

cooling water discharge rate from inboard marine diesel engines varies based on power levels, 

but typically averages around 20 gpm when engines operate between 1,500 and 2,000 rpm 

(Sherwood Pumps, 2009). Marine diesel generator sets require 5 to 6 gpm of cooling water for 

smaller units (9.5 kW) (Cummins, 2008), and up to 20 and 25 gpm of cooling water for larger 

marine generator sets (80 kW) (Cummins, 2004). Daily discharge rates for these engines are a 

function of daily operating time. 

261 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Collecting the Engine Effluent of a Water Taxi at Idle 

Collecting the Engine Effluent of a Tow and Salvage Vessel at Full Speed 

For this study, EPA collected engine cooling water discharge samples from a variety of 

vessel classes with different engine types, as summarized in Table 3.6.1. Note that two of the 

sampled vessels are recreational vessels and are not study vessels. In addition, both of the 

sampled research vessels and four of the six sampled tow/salvage vessels (those with outboard 

propulsion engines) were manufactured for pleasure and therefore are also recreational vessels 

and not study vessels. EPA sampled engine effluent from these vessels because all of the 

sampled engines can be installed on either recreational or nonrecreational vessels and are 

representative of engines on study vessels. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

 Samples were analyzed for classical pollutants, metals (dissolved and total), SVOCs, and 

VOCs. Engine discharge samples were typically collected from the discharge port using a sample 

transfer jar attached to a pole. The contents of the sample transfer jar were poured into a lined 

utility bucket. If the engines were operated at multiple engine levels (e.g., idle, half power, full 

power), then equal portions of sample were collected from each power level and composited for 

a single laboratory analysis. Ten of the 13 sampled vessels with inboard propulsion engines and 

all six sampled vessels with outboard propulsion engines were operated at multiple power levels. 

Similarly, if a vessel operated more than one engine, then equal portions of sample were 

collected from each engine and composited for a single laboratory analysis. However, samples 

for analysis of oil and grease and VOCs are not appropriate to composite. For these analytes, 

samples were collected and analyzed separately for each engine power level or were collected 

from only one of the multiple engines. 

Table 3.6.1. Sampled Engine Characteristics 

Fuel Type Cooling Type Engine Wet 

Exhaust? 

Number of Vessels 

Sampled Vessel Types 

Inboard Propulsion Engines 

Diesel Direct Yes 3 Water Taxi (2), Fishing 

Diesel Indirect Yes 5 Tour Boat (2), Water Taxi, Tow/Salvage, Fire 

Boat 

Diesel Unknown Yes 3 Tour Boat, Water Taxi, Recreational 

Diesel Unknown Unknown 1 Fishing 

Gasoline Indirect Yes 1 Recreational 

Outboard Propulsion Engines 

Gasoline Direct Yes 5 Tow/Salvage (4), Research 

Gasoline Unknown Yes 1 Research 

Generator Engines 

Diesel Direct Yes 1 Tour Boat 

Diesel Indirect Yes 1 Fire Boat 

Diesel Unknown Unknown 2 Fishing, Tour Boat 

Unknown Indirect Yes 1 Water Taxi 

EPA also observed a number of vessels, particularly tug boats and larger commercial 

fishing vessels, that use keel-cooled propulsion and generator engines. The vessels were not 

sampled as these closed-loop cooling systems do not have a discharge. Approximately two-thirds 

of the 61 vessels visited had keel cooled engine systems. 

An additional source of relevant engine effluent data is EPA’s sampling program for the 

Uniform National Discharge Standards (UNDS) rulemaking. In 2006, EPA sampled propulsion 

engine wet exhaust discharges from two small Armed Forces vessels with inboard diesel engines 

with engine wet exhaust: a 36-foot landing craft personnel large (LCPL) and a 7-meter rigid 

inflatable boat (RIB) (USEPA, 2008b). This sampling program was specifically designed to 

263 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

characterize engine wet exhaust discharges by power level. While these Armed Forces vessels 

are not study vessels, the engines used on these vessels are comparable to those used on study 

vessels. Samples from both vessels were analyzed for eight classical pollutants and 92 volatile 

and semivolatile compounds. Samples from the LCPL were also analyzed for seven total metals. 

Grab samples of the engine discharge were collected from sample taps installed into the exhaust 

lines of the vessels. Three replicate engine discharge samples were collected at each of five 

different engine power levels: 0 percent (idle), 25 percent, 50 percent, 75 percent, and 100 

percent (full power). Three replicate background seawater samples were also collected. Sampling 

was conducted in the open ocean. 

3.2.6.1 Inboard Propulsion Engines 

For this study, EPA collected cooling water discharge samples from inboard propulsion 

engines on 13 vessels: four water taxis, three tour boats, two fishing vessels, one tow/salvage 

vessel, one fire boat, and two recreational vessels (Table 3.6.1). These engines included both 

direct and indirect cooling discharges from both gasoline- and diesel-fueled engines. For the 

UNDS program, EPA sampled engine wet exhaust from inboard propulsion engines on two 

personnel craft. Results for each class of pollutant are presented and discussed in the following 

subsections. 

The Inboard Propulsion Engine of a Fire Boat 

264 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.1.1 Classical Pollutants 

Table 3.6.2 presents analytical results for 11 classical pollutants detected in samples of 

discharges from inboard propulsion engines. All of the classical pollutants analyzed for were 

detected and the detected results are shown in Figure 3.6.1. Engine cooling water discharge 

differs from all other discharges in that the water used in the engines is drawn from surrounding 

waters and immediately discharged to the same waters. For this reason, EPA analyzed the sample 

results to determine which pollutant concentrations were contributed primarily by engine 

operations and which were contributed primarily by background ambient concentrations (see 

footnotes on Table 3.6.2 and Figure 3.6.1). The remainder of this subsection discusses those 

pollutants found to be contributed primarily by engine operations. 

Temperature increases in engine effluent above background were generally less than 5°C. 

However, on three vessels operated at higher power levels (recreational vessel, tow/salvage 

vessel, and fire boat), temperature increases were greater than 20°C. EPA’s findings were similar 

for the UNDS sampling program, with temperature increases ranging from less than 3°C at idle 

to a maximum of 27°C at full power. 

Oil and grease (measured as HEM) was detected in the majority of engine effluent 

samples; however, detected concentrations were low (most were less than 5 mg/L). All sample 

results were well below the 33 CFR § 151.10 and MARPOL prohibition of the discharge of oil 

and oily mixtures with an oil content greater than 15 ppm into seawater from vessels. HEM 

values exceeded 5 mg/L in only three grab samples, and all three were collected during engine 

operation at relatively high power levels. For the UNDS sampling program, HEM was not 

detected in any engine effluent samples, regardless of power level (≤ 4 mg/L). 

Sulfide was detected in only two of 11 samples at concentrations of 0.013 and 0.016 

mg/L. These measured concentrations are six to eight times greater than the most conservative 

PHQ screening benchmark of 0.002 mg/L. Sulfide might be present as a trace constituent in the 

fuel, as a product of incomplete combustion, or due to formation within the biofilm in the 

cooling system piping. For the UNDS sampling program, sulfide was not detected in any engine 

wet exhaust samples. 

For this study, TSS concentrations in effluent discharge samples were contributed 

primarily by background ambient concentrations (i.e., sample concentrations ranged from <5 to 

17 mg/L while ambient water concentrations ranged from 7.8 to 20 mg/L). For the UNDS 

sampling program, TSS was not detected in any of the samples from the LCPL; however, TSS 

was present in the RIB discharge samples at concentrations ranging from 6 to 14 mg/L, which 

were statistically greater than background for some power levels. UNDS TSS results correspond 

with the field observations for samples from the RIB at the highest power levels (i.e., the 

samples were observed to be cloudy and contained settleable materials (resembling soot)). In this 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

266 

study, EPA observed that some effluent engine samples were also cloudy and contained 

settleable materials at higher power levels. 

TRC was detected in only one engine effluent sample collected from a fishing vessel at a 

concentration of 0.17 mg/L. Fish hold effluent from this vessel, containing TRC at a 

concentration of 0.27 mg/L, was discharged into the water surrounding the vessel just prior to 

collection of engine effluent samples; the propulsion engine on this vessel utilizes the ambient 

water for cooling. EPA believes that the TRC value for the engine effluent sample was likely 

influenced by the fish hold effluent discharge.
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.2. Results of Inboard Propulsion Engine Sample Analyses for Classical Pollutants1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Conductivity2 mS/cm 10 6 100 11 6.1 0.22 0.22 0.22 17 Dissolved Oxygen3 mg/L 10 6 100 6.8 7.4 1.7 2.0 4.0 9.3 Hexane Extractable Material (HEM) mg/L 12 8 66 3.0 2.2 3.8 pH2 SU 13 13 100 6.9 6.6 6.2 6.2 6.4 7.4 Salinity2 ppt 10 10 100 6.9 3.3 0.10 0.10 0.10 9.9 Silica Gel Treated HEM (SGT-HEM) mg/L 12 7 58 4.0 2.6 3.6 Sulfide mg/L 11 2 18 0.0062 Temperature C 13 13 100 22 21 6.5 9.9 17 26 Total Residual Chlorine2 mg/L 13 1 7.7 0.048 Total Suspended Solids (TSS) 3 mg/L 11 8 73 11 13 16 Turbidity3 NTU 13 13 100 32 29 1.2 2.7 18 45 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in ambient water. (3) Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background concentrations in ambient water. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

268 

Figure 3.6.1. Box and Dot Density Plot of Classical Pollutant Values Measured in Samples 

of Inboard Propulsion Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

Cond(mS/cm)*

DO (mg/l)**

HEM (mg/l)

SGT-H (mg/l)

Salin.(ppt)*

Sulf. (mg/l)

TRC (mg/l)*

TSS (mg/l)**

Temp. (C)

Turb(NTU)**

pH (SU)*

Classical Pollutant

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3.2.6.1.2 Metals 

Inboard propulsion engine effluent samples were analyzed for 22 dissolved and total 

metals. Table 3.6.3 presents analytical results for the 16 metals that were detected in one or more 

engine effluent samples. The detected results are also shown in Figures 3.6.2 and 3.6.3 for 

dissolved and total metals, respectively. Figures 3.6.4 and 3.6.5 display the distribution of PHQs 

based on the screening benchmark for each of the dissolved and total metals. EPA analyzed the 

sample results to determine which metals were contributed primarily by engine operations and 

which were contributed primarily by background ambient concentrations. The remainder of this 

subsection discusses those metals found to be contributed primarily by engine operations. 

For most metals, concentrations for the dissolved and total forms were similar, indicating 

that engine operations contribute metals in dissolved rather that particulate form. Two exceptions 

were iron and lead. A comparison of dissolved and total iron concentrations indicates that almost 

all iron was present in particulate form. One possible source of particulate iron in engine effluent 

is rust. Lead was detected in engine effluent samples from only four of the 13 vessels sampled 

(three water taxis and a tow/salvage vessel). Total lead concentrations (maximum measured 

concentration = 9.6 μg/L) exceeded dissolved lead concentrations by three to four times. 

Dissolved and total copper were detected in almost all engine effluent samples at 

concentrations ranging from 3 to 53 μg/L and 5 to 66 μg/L, respectively. Dissolved copper 

concentrations exceeded the PHQ screening benchmark of 3.1 μg/L (saltwater chronic criterion) 

by one to 17 times (see Figure 3.6.4). In contrast, none of the total copper concentrations 

exceeded the PHQ screening benchmark of 1,300 μg/L (human heath for consumption of water 

and aquatic organisms (see Figure 3.6.5)). 

Dissolved and total zinc were also detected in a majority of engine effluent samples. 

Detected concentrations ranged from 12 to 120 μg/L and 11 to 95 μg/L for dissolved and total 

zinc, respectively (see Figures 3.6.2 and 3.6.3). However, only the two highest detected 

dissolved zinc concentrations (83 and 120 μg/L) exceeded the PHQ screening benchmark of 81 

μg/L (saltwater chronic criterion). None of the detected total zinc concentrations exceeded the 

PHQ screening benchmark of 7,400 μg/L (human heath for consumption of water and aquatic 

organisms). 

Dissolved and total nickel were detected in approximately half of the engine effluent 

samples, and dissolved and total chromium and lead were each detected in fewer than half of the 

engine effluent samples. Detected concentrations were generally within five times the reporting 

limit and none exceeded the screening benchmarks for these analytes (see Figures 3.6.4 and 

3.6.5). Note, however, that lead is a persistent bioaccumulative and toxic chemical (PBT) and the 

long-term mass loading is more important than the discharge concentrations. 

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270 

Dissolved manganese was detected in 11 of 13 engine effluent samples. Manganese was 

predominantly in particulate form in background ambient water; therefore, EPA assumed 

dissolved manganese concentrations in engine effluent samples to be contributed by engine 

operations. NRWQCs or other PHQ screening benchmarks have not been determined for 

dissolved manganese. 

Dissolved iron and dissolved and total vanadium were each detected in no more than 

three engine effluent samples at measured concentrations close to the reporting limit. NRWQCs 

or other PHQ screening benchmarks have not been determined for these analytes at this time. 

Finally, the concentrations in engine effluent discharges that exceeded the PHQ screening 

benchmark concentrations for dissolved selenium, total aluminum, and total arsenic were caused 

by high background concentrations in ambient water (which exceeded benchmark 

concentrations) and not by engine operations. Moreover, in the case of dissolved and total 

arsenic and selenium, measured concentrations above their respective reporting limits (three 

different water taxis and the recreational vessel) may be substantially elevated due to positive 

interference (see Section 3.1.3). After subtracting the contribution of ambient water (also 

potentially elevated due to positive interference), none of the detected concentrations exceeded 

their PHQ screening benchmarks. 

Comparing study sampling results with the metals data from the engine wet exhaust 

sampling conducted for the UNDS program affirms EPA’s sampling results. For the UNDS 

program, EPA determined that five of the seven total metals analyzed for were present at 

concentrations statistically greater than background: cadmium, chromium, copper, lead, and 

nickel. Total mercury was not detected in any samples, and total arsenic concentrations did not 

exceed background concentrations. Table 3.6.4 compares the metals results from this study and 

the UNDS program. 

EPA notes that there were some important differences between the UNDS sampling and 

the sampling conducted in this study to consider when comparing the results. The UNDS 

program used a different analytical method, as well as a different methodology to calculate mean 

concentrations. Also, background metals concentrations in harbors for this study are greater than 

those in the open ocean for the UNDS program. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.3. Results of Inboard Propulsion Engine Sample Analyses for Metals1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Heavy and Other Metals 

Aluminum, Dissolved2 μg/L 13 12 92 200 100 3.8 23 180 Aluminum, Total2 μg/L 13 13 100 340 300 59 61 120 410 Arsenic, Dissolved3,4 μg/L 13 4 31 4.2 8.7 Arsenic, Total3,4 μg/L 13 6 46 4.5 8.7 Barium, Dissolved2 μg/L 7 7 100 35 32 23 23 29 34 Barium, Total2 μg/L 7 7 100 36 34 24 24 28 35 Chromium, Dissolved μg/L 13 3 23 1.2 0.75 Chromium, Total μg/L 13 3 23 1.3 0.95 Copper, Dissolved μg/L 13 12 92 16 6.6 1.6 5.5 23 Copper, Total μg/L 13 11 85 18 9.3 5.6 25 Iron, Dissolved μg/L 7 1 14 64 Iron, Total3 μg/L 7 6 86 250 250 150 310 Lead, Dissolved μg/L 13 3 23 1.5 0.60 Lead, Total μg/L 13 4 31 3.0 4.1 Manganese, Dissolved μg/L 13 11 85 43 44 30 55 Manganese, Total2 μg/L 13 11 85 55 53 40 74 Nickel, Dissolved μg/L 13 7 54 4.4 2.5 4.3 Nickel, Total2 μg/L 13 7 54 4.6 3.1 4.3 Selenium, Dissolved2,4 μg/L 13 4 31 11 21 Selenium, Total3,4 μg/L 13 4 31 11 21 Vanadium, Dissolved μg/L 7 3 43 0.90 1.4 Vanadium,Total μg/L 7 2 29 1.4 1.1 Zinc, Dissolved μg/L 13 9 69 38 23 74 Zinc, Total μg/L 13 11 85 38 29 11 75 

Cationic Metals 

Calcium, Dissolved2 μg/L 13 13 100 80000 37000 24000 24000 26000 62000 

271 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

272 

Table 3.6.3. Results of Inboard Propulsion Engine Sample Analyses for Metals1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Calcium, Total2 μg/L 13 13 100 81000 37000 26000 26000 29000 62000 Magnesium, Dissolved2 μg/L 13 13 100 200000 12000 5200 5200 5900 16000Magnesium, Total2 μg/L 13 13 100 200000 12000 5800 5900 6500 16000Potassium, Dissolved2 μg/L 7 7 100 32000 39000 4000 4000 4100 58000 Potassium, Total2 μg/L 7 7 100 32000 39000 3700 3700 3800 58000 Sodium, Dissolved3 μg/L 7 7 100 770000 860000 36000 36000 40000 160000Sodium,Total3 μg/L 7 7 100 860000 860000 35000 35000 39000 160000

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in ambient water. (3) Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background concentrations in ambient water. (4) Values well above their respective reporting limits are suspected of being elevated due to positive interference. (See discussion in Section 3.1.3). 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Table 3.6.4. Comparison of Metals Results for EPA P.L. 110-299 and UNDS Engine Wet 

Exhaust Sampling 

Mean Inboard Propulsion Engine Effluent Concentration (μg/L) Metal EPA P.L. 110-299 Sampling UNDS Engine Wet Exhaust Sampling 

Arsenic, Total 4.5 2.2 

Cadmium, Total Not Detected (Reporting Limit = 1) 0.024 

Chromium, Total 1.3 0.33 

Copper, Total 18 24 

Lead, Total 3.0 0.2 

Nickel, Total 4.6 6.8 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

274 

Figure 3.6.2. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Inboard Propulsion Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Values well above their respective reporting limits for dissolved arsenic and selenium are suspected of being 

elevated due to positive interference). 

Aluminum*

Arsenic**

Barium*

Chromium

Copper

Iron

Lead

Manganese

Nickel

Selenium*

Vanadium

Zinc

Dissolved Metals

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

275 

Figure 3.6.3. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Inboard Propulsion Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Values well above their respective reporting limits for total arsenic and selenium are suspected of being 

substantially elevated due to positive interference).

Aluminum*

Arsenic**

Barium*

Chromium

Copper

Iron**

Lead

Manganese*

Nickel*

Selenium**

Vanadium

Zinc

Total Metals

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

276 

Figure 3.6.4. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals 

in Samples of Inboard Propulsion Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Replacement values for non-detects are circled. Also, values well above their respective reporting limits for 

dissolved arsenic and selenium are suspected of being elevated due to positive interference). 

Aluminum*

Arsenic**

Barium*

Chromium

Copper

Iron

Lead

Manganese

Nickel

Selenium*

Vanadium

Zinc

Dissolved Metals

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277 

Figure 3.6.5. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Inboard Propulsion Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Replacement values for non-detects are circled. Also, values well above their respective reporting limits for 

total arsenic and selenium are suspected of being elevated due to positive interference).

100.00

Aluminum*

Arsenic**

Barium*

Chromium

Copper

Iron**

Lead

Manganese*

Nickel*

Selenium**

Vanadium

Zinc

Total Metals

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.1.3 Semivolatile Organic Compounds 

Inboard propulsion engine effluent samples were analyzed for 76 SVOCs for the 

sampling conducted as part of the P.L. 110-299 study. Table 3.6.5 presents analytical results for 

the 31 SVOCs that were detected in one or more engine effluent samples. The detected results 

are also shown in Figures 3.6.6 and 3.6.7 for analyte concentrations and for PHQs based on the 

lowest NRWQC or other PHQ screening benchmark where applicable, respectively. EPA 

analyzed the sample results to determine which SVOCs were contributed primarily by engine 

operations and which were contributed primarily by background ambient concentrations. All 

were found to be contributed primarily by engine operations. 

Many of the detected SVOCs can be classified among the following pollutant classes: 

polycyclic aromatic hydrocarbons or PAHs (14 analytes), straight-chain hydrocarbons (five 

analytes), phenol and methyl phenols (five analytes), and phthalates (two analytes). These 

include all of the SVOCs detected most frequently and at the highest concentrations. 

PAHs are present in fuel in small amounts and may be formed as products of incomplete 

combustion. EPA has identified seven PAHs as probable human carcinogens, six of which were 

detected in engine effluent collected from a recreational vessel with a gasoline engine 

dewinterized immediately prior to sampling (see details below): benzo(a)anthracene, 

benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, chrysene, and indeno(1,2,3-

cd)pyrene. Most of these compounds exceed a PHQ of 1,000 as shown in Figure 3.6.7. 

Phthalates are plasticizers (chemicals added to plastics to make them flexible) and are 

commonly detected in environmental samples (ATSDR, 2002). Bis(2-ethylhexyl) phthalate was 

detected at concentration just above the screening benchmark of 1.2 μg/L (human heath for 

consumption of water and aquatic organisms). 

Phenol and methyl phenols are present in petroleum products and may also be generated 

as products of incomplete combustion. Discharges of phenol and methyl phenols are assumed to 

not cause any environmental impacts as detected concentrations did not exceed the PHQ 

screening benchmarks for these analytes. Straight-chain (alkane) hydrocarbons are also 

components of fuel; none of the straight-chain hydrocarbons detected in engine effluent have a 

NRWQC or other PHQ screening benchmark, and they are not PBT chemicals 

It is important to note that 11 of the detected SVOCs were found only in one sample 

collected from a recreational vessel (recreational vessels are not study vessels). These included 

all six of the detected PAHs that are probable human carcinogens, as well as four additional 

PAHs. Engine effluent from this recreational vessel also contributed the maximum detected 

concentrations for six additional analytes, including several additional PAHs as well as four of 

the five detected phenol/methyl phenols. (Maximum sample concentrations for 2,4-

dimethylphenol, straight-chain hydrocarbons, and phthalates were contributed by other vessels.) 

278 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

279 

This recreational vessel was the only sampled vessel that used gasoline as fuel rather than diesel; 

however, the lack of replication precludes any determination as to whether fuel type is a critical 

factor for engine effluent characteristics. In addition, the engines on this vessel were 

dewinterized immediately prior to sampling. The lack of engine operation for several months 

prior to sampling could have contributed to engine effluent characteristics. 

Comparing study sampling results with the results from the engine wet exhaust sampling 

conducted for the UNDS program reveals some similarities. For the LCPL, phenol and bis(2-

ethylhexyl)phthalate were the only detected SVOCs; however, the presence of bis(2-ethyhexyl) 

phthalate in LCPL effluent may be due to laboratory contamination and so data for the purpose 

of comparison are not shown in this report. For the RIB, phenol was the only detected SVOC. 

EPA determined that phenol was present at concentrations statistically greater than background. 

Table 3.6.6 compares the phenol results from this study to those from the UNDS program. Note 

that the UNDS program used a different methodology to calculate mean concentrations. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.5. Results of Inboard Propulsion Engine Sample Analyses for SVOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

1,2-Diethyl-Cyclobutane μg/L 1 1 100 10 1,6-Dimethyl μg/L 1 1 100 35 1-Methylnaphthalene μg/L 2 2 100 13 24 3.2 3.2 3.2 24 2,4-Dimethylphenol μg/L 12 4 33 3.7 2.4 2-Methylnaphthalene μg/L 8 6 75 17 13 0.90 36 Acenaphthene μg/L 12 1 8.3 2.0 Acenaphthylene μg/L 12 3 25 7.0 1.7 Anthracene μg/L 12 1 8.3 3.3 Benzo(a)anthracene μg/L 12 1 8.3 3.3 Benzo(a)pyrene μg/L 12 1 8.3 3.2 Benzo(b)fluoranthene μg/L 12 1 8.3 2.8 Benzo(g,h,i)perylene μg/L 12 1 8.3 2.6 Benzo(k)fluoranthene μg/L 12 1 8.3 3.1 Bis(2-ethylhexyl) phthalate μg/L 12 4 33 1.7 1.2 Chrysene μg/L 12 1 8.3 3.3 Di-n-butyl phthalate μg/L 12 6 50 1.7 1.1 1.6 Eicosane μg/L 2 2 100 19 28 10 10 10 28 Fluorene μg/L 12 4 33 3.5 2.8 Heptadecane μg/L 4 4 100 29 27 3.5 3.5 3.8 67 Indeno(1,2,3-cd) μg/L 12 1 8.3 2.5 m-Cresol μg/L 4 1 25 13 34 Naphthalene μg/L 12 10 8.3 30 6.6 1.9 34 n-Hexadecane μg/L 3 3 100 26 17 3.1 3.1 3.1 57 Nonadecane μg/L 2 2 100 27 38 15 15 15 38 Nonanoic Acid μg/L 1 1 100 11 o-Cresol μg/L 3 3 100 6.6 5.8 5.7 5.7 5.7 8.4 

280 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

281 

Table 3.6.5. Results of Inboard Propulsion Engine Sample Analyses for SVOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Octadecane μg/L 2 2 100 10 17 3.1 3.1 3.1 17 p-Cresol μg/L 7 5 71 26 17 24 Phenanthrene μg/L 12 3 25 6.1 1.3 Phenol μg/L 12 8 67 27 3.7 37 Pyrene μg/L 12 1 8.3 6.6 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in ambient water. 

(3) Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background concentrations in ambient water. 

Table 3.6.6. Comparison of Phenol Results for EPA P.L. 110-299 and UNDS Engine Wet Exhaust Samplin

Mean Inboard Propulsion Engine Effluent Concent

UNDS Small Boat Engine W

Analyte EPA P.L. 110-299 Sampling 

LCPL 

Phenol 27 13 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

282 

Figure 3.6.6. Box and Dot Density Plot of SVOC Concentrations Measured in P.L. 110-299 

Study Samples of Inboard Propulsion Engine Effluent 

SVOCs are identified as follows: 

(1) 1,2-Diethyl-Cyclobutane 

(2) 1,6-dimethylnaphthalene 

(3) 1-methylnaphthalene 

(4) 2,4-Dimethylphenol 

(5) 2-Methylnaphthalene 

(6) Acenaphthene 

(7) Acenaphthylene 

 (8) Anthracene 

(9) Benzo(a)anthracene 

(10) Benzo(a)pyrene 

(11) Benzo(b)fluoranthene 

(12) Benzo(g,h,i)perylene 

(13) Benzo(k)fluoranthene 

(14) Bis(2-ethylhexyl) phthalate 

(15) Chrysene 

(16) Di-n-butyl phthalate 

(17) Eicosane 

(18) Fluorene 

(19) Heptadecane 

(20) Indeno(1,2,3-cd)pyrene 

(21) m-Cresol 

(22) Naphthalene 

(23) n-Hexadecane 

(24) Nonadecane 

(25) Nonanoic Acid 

(26) o-Cresol 

(27) Octadecane 

(28) p-Cresol 

(29) Phenanthrene 

(30) Phenol 

(31) Pyrene 

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

SVOCs

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Figure 3.6.7. Box and Dot Density Plot of Potential Hazard Quotients for SVOCs in P.L. 

110-299 Study Samples of Inboard Propulsion Engine Effluent 

SVOCs are identified as follows (replacement values for non-detects are circled): 

(1) 1,2-Diethyl-Cyclobutane 

(2) 1,6-dimethylnaphthalene 

(3) 1-methylnaphthalene 

(4) 2,4-Dimethylphenol 

(5) 2-Methylnaphthalene 

(6) Acenaphthene 

(7) Acenaphthylene 

(8) Anthracene 

(9) Benzo(a)anthracene 

(10) Benzo(a)pyrene 

(11) Benzo(b)fluoranthene 

(12) Benzo(g,h,i)perylene 

(13) Benzo(k)fluoranthene 

(14) Bis(2-ethylhexyl) phthalate 

(15) Chrysene 

(16) Di-n-butyl phthalate 

(17) Eicosane 

(18) Fluorene 

(19) Heptadecane 

(20) Indeno(1,2,3-cd)pyrene 

(21) m-Cresol 

(22) Naphthalene 

(23) n-Hexadecane 

(24) Nonadecane 

(25) Nonanoic Acid 

(26) o-Cresol 

(27) Octadecane 

(28) p-Cresol 

(29) Phenanthrene 

(30) Phenol 

(31) Pyrene 

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

SVOCs

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.1.4 Volatile Organic Compounds 

Inboard propulsion engine effluent samples were analyzed for 84 VOCs. Table 3.6.7 

presents analytical results for the 38 VOCs that were detected in one or more engine effluent 

samples. The detected results are also shown in Figures 3.6.8 and 3.6.9 for analyte 

concentrations and for PHQs based on the lowest NRWQC or other PHQ screening benchmark 

where applicable, respectively. EPA analyzed the sample results to determine which VOCs were 

contributed primarily by engine operations and which were contributed primarily by background 

ambient concentrations. All were found to be contributed primarily by engine operations. 

Approximately one-third of the detected VOCs were frequently detected in engine 

effluent (i.e., greater than half of the sampled vessels). Some of these compounds are volatile 

constituents of fuel, specifically benzene, toluene, ethylbenzene, and xylene. Others are 

trimethylbenzenes, which are naturally present in fuel, and ketones, which may be formed as 

products of incomplete combustion. Among these compounds, only benzene and toluene have an 

NRWQC. Approximately half of the detected benzene concentrations (from water taxis, tour 

boats and a recreational vessels) exceeded the PHQ screening benchmark of 2.2 μg/L (human 

heath for consumption of water and aquatic organisms), including discharges from one vessel 

that exceeded the benchmark by a factor of more than 50 (the next highest concentration that 

exceeded the benchmark was by less than a factor of 4) (see Figure 3.6.9). None of the detected 

toluene concentrations exceeded the PHQ screening benchmark of 1,300 μg/L (human health for 

consumption of water and aquatic organisms). 

Approximately one-third of the detected VOCs were detected relatively infrequently (i.e., 

detected in fewer than half the sampled vessels). Among these compounds, only chloroform and 

methylene chloride have an NRWQC. However, none of the detected concentrations for these 

two analytes exceeded the PHQ screening benchmarks of 5.7 μg/L (human heath for 

consumption of water and aquatic organisms) and 1,300 μg/L (human heath for consumption of 

water and aquatic organisms), respectively. 

The final third of detected VOCs were detected in engine effluent from only one or two 

vessels. None of these analytes have an NRWQC or are PBT chemicals, and are therefore not 

expected to have the potential to pose risk to human health or the environment. 

It is important to note the maximum detected concentrations for 11 of the VOCs were 

found in samples collected from a recreational vessel (recreational vessels are not study vessels). 

These included benzene, toluene, ethylbenzene, xylene, and trimethylbenzenes (maximum 

sample concentrations for ketones were contributed by other vessels). As noted above, this 

recreational vessel was the only sampled vessel that used gasoline as fuel rather than diesel; 

however, this data set is too small to demonstrate whether fuel type is a critical factor for engine 

effluent characteristics. In addition, the engines on this vessel were dewinterized immediately 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

285 

prior to sampling. The lack of engine operation for several months prior to sampling could have 

contributed to engine effluent characteristics. 

Comparing these sampling results with the results from the engine wet exhaust sampling 

conducted for the UNDS program reveals some similarities. For the LCPL, no VOCs were 

detected. For the RIB, 1,2,3-trimethylbenzene, and 1,3,5-trimethylbenzene were the detected 

VOCs. However, EPA determined that the trimethylbenzenes were not present at concentrations 

statistically greater than background. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.7. Results of Inboard Propulsion Engine Sample Analyses for VOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. 2 Median Conc. Minimum Conc. 10% 25% 75% 

(2-Methyl-1-Propenyl)-Benzene μg/L 1 1 1.00 3.2 1,2,3,4-Tetrahydro-5-Methylnaphthalene μg/L 1 1 1.00 24 1,2,3,4-Tetrahydro-6-Methylnaphthalene μg/L 2 2 1.00 19 33 4.6 4.6 4.6 33 1,2,3,4-Tetrahydro μg/L 2 2 1.00 12 22 3.2 3.2 3.2 22 1,2,4-Trimethylbenzene μg/L 7 7 1.00 6.1 1.8 0.12 0.12 0.30 3.8 1,3,5-Trimethylbenzene μg/L 7 5 0.71 2.1 0.70 0.92 1,3-Methylnaphthalene μg/L 1 1 1.00 4.2 1,7-Methylnaphthalene μg/L 1 1 1.00 19 2,3-Dihydro-4-Methyl-1HIndene μg/L 1 1 1.00 53 2,6-Dimethyl μg/L 1 1 1.00 41 2-Butanone μg/L 7 7 1.00 17 7.8 2.6 2.6 3.0 32 2-Ethyl-1,3,5-TrimethylBenzene μg/L 1 1 1.00 4.4 2-Ethyl-1,4-DimethylBenzene μg/L 1 1 1.00 20 2-Hexanone μg/L 7 5 0.71 2.1 1.1 2.9 4-Isopropyltoluene μg/L 7 3 0.43 1.8 1.3 4-Methyl-2-Pentanone μg/L 7 3 0.43 1.9 0.80 Acetone μg/L 8 8 1.00 58 34 6.0 6.0 15 110 Benzene μg/L 12 9 0.75 12 2.3 0.17 5.4 Benzocycloheptatriene μg/L 1 1 1.00 39 Biphenyl μg/L 8 6 0.75 4.1 3.0 0.27 4.5 Chloroform μg/L 12 4 0.33 1.7 1.0 Dimethocxymethane μg/L 1 1 1.00 89 Ethylbenzene μg/L 12 6 0.50 2.3 0.10 0.83 Isopropylbenzene μg/L 7 3 0.43 1.9 1.4 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human 

287 

Table 3.6.7. Results of Inboard Propulsion Engine Sample Analyses for VOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. 2 Median Conc. Minimum Conc. 10% 25% 75% 

m-,p-Xylene (sum of isomers) μg/L 7 7 1.00 11 1.8 0.30 0.30 0.90 2.0 Methyl acetate μg/L 7 1 0.14 2.4 Methyl tertiary butyl ether (MTBE) μg/L 7 1 0.14 2.4 Methylene chloride μg/L 12 4 0.33 1.2 0.14 n-Butylbenzene μg/L 7 3 0.43 1.8 1.0 n-Pentadecane μg/L 2 2 100 24 31 16 16 16 31 n-Propylbenzene μg/L 7 4 57 1.5 0.15 0.40 n-Tetradecane μg/L 2 2 100 20 33 6.5 6.5 6.5 33 O-Xylene μg/L 7 7 100 5.5 1.5 0.20 0.20 0.65 1.8 sec-Butylbenzene μg/L 7 1 14 2.3 Styrene μg/L 7 7 100 6.1 1.3 0.13 0.13 0.50 3.4 Toluene μg/L 12 8 67 11 0.90 2.8 Trichlorofluoromethane μg/L 12 1 8.3 2.1 Vinyl acetate μg/L 7 1 14 2.4 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) In some cases, the detected concentration(s) for an analyte could be lower than the replacement value (1⁄2 of the reporting limit) for a concentration tha

extreme (but possible) case, this could result in an average concentration for an analyte that is greater than the maximum detected concentration. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

288 

Figure 3.6.8. Box and Dot Density Plot of Volatile Organic Compounds Concentrations 

Measured in P.L. 110-299 Study Samples of Inboard Propulsion Engine Effluent 

VOCs are identified as follows: 

(1) (2-Methyl-1-Propenyl)-

Benzene 

(2) 1,2,3,4-Tetrahydro-5-

Methylnaphthalene 

(3) 1,2,3,4-Tetrahydro-6-

Methylnaphthalene 

(4) 1,2,3,4-

Tetrahydronaphthalene 

(5) 1,2,4-Trimethylbenzene 

(6) 1,3,5-Trimethylbenzene 

(7) 1,3-Methylnaphthalene 

(8) 1,7-Methylnaphthalene 

(9) 2,3-Dihydro-4-Methyl-1HIndene 

(10) 2,6-dimethylnaphthalene 

(11) 2-Butanone 

(12) 2-Ethyl-1,3,5-TrimethylBenzene 

(13) 2-Ethyl-1,4-DimethylBenzene 

(14) 2-Hexanone, 

(15) 4-Isopropyltoluene 

(16) 4-Methyl-2-Pentanone 

(17) Acetone 

(18) Benzene 

(19) Benzocycloheptatriene 

(20) Biphenyl 

(21) Chloroform 

(22) Dimethoxymethane 

(23) Ethylbenzene 

(24) Isopropylbenzene 

(25) m-,p-Xylene (sum of 

isomers) 

(26) Methyl acetate 

(27) Methyl tertiary butyl ether 

(MTBE) 

(28) Methylene chloride 

(29) n-Butylbenzene, 

(30) n-Pentadecane 

(31) n-Propylbenzene 

(32) n-Tetradecane 

(33) O-Xylene 

(34) sec-Butylbenzene 

(35) Styrene 

(36) Toluene 

(37) Trichlorofluoromethane 

(38) Vinyl acetate 

0 2 4 6 8 10121416182022242628303234363840

VOCs

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Figure 3.6.9. Box and Dot Density Plot of Potential Hazard Quotients for Volatile Organic 

Compounds in P.L. 110-299 Study Samples of Inboard Propulsion Engine Effluent 

VOCs are identified as follows (replacement values for non-detects are circled): 

(1) (2-Methyl-1-Propenyl)-

Benzene 

(2) 1,2,3,4-Tetrahydro-5-

Methylnaphthalene 

(3) 1,2,3,4-Tetrahydro-6-

Methylnaphthalene 

(4) 1,2,3,4-

Tetrahydronaphthalene 

(5) 1,2,4-Trimethylbenzene 

(6) 1,3,5-Trimethylbenzene 

(7) 1,3-Methylnaphthalene 

 (8) 1,7-Methylnaphthalene 

(9) 2,3-Dihydro-4-Methyl-1HIndene 

(10) 2,6-dimethylnaphthalene 

(11) 2-Butanone 

(12) 2-Ethyl-1,3,5-TrimethylBenzene 

(13) 2-Ethyl-1,4-DimethylBenzene 

(14) 2-Hexanone 

(15) 4-Isopropyltoluene 

(16) 4-Methyl-2-Pentanone 

(17) Acetone 

(18) Benzene 

(19) Benzocycloheptatriene 

(20) Biphenyl 

(21) Chloroform 

(22) Dimethoxymethane 

(23) Ethylbenzene 

(24) Isopropylbenzene 

(25) m-,p-Xylene (sum of 

isomers) 

(26) Methyl acetate 

(27) Methyl tertiary butyl ether 

(MTBE) 

(28) Methylene chloride 

(29) n-Butylbenzene 

(30) n-Pentadecane 

(31) n-Propylbenzene 

(32) n-Tetradecane 

(33) O-Xylene 

(34) sec-Butylbenzene 

(35) Styrene 

(36) Toluene 

(37) Trichlorofluoromethane 

(38) Vinyl acetate 

0 2 4 6 8 10121416182022242628303234363840

VOCs

0.0001

0.0010

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0.1000

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.2 Outboard Propulsion Engines 

For this study, EPA collected samples of discharges from outboard propulsion engines on 

six vessels: four tow/salvage vessels and two research vessels (see Table 3.6.1 above). It is 

important to note that all six of these vessels were confirmed by the vessel owners/operators to 

be manufactured for pleasure. Vessels manufactured for pleasure are defined as recreational 

vessels under P.L. 110-288 and are not study vessels. Nonetheless, EPA has included the results 

here assuming they are representative of vessels with outboard propulsion engines, some of 

which may be study vessels. EPA also collected these results so that the Agency could later 

compare results between study vessels and recreational vessels if appropriate. 

The Outboard Engine of a Tow and Salvage Vessel 

3.2.6.2.1 Classical Pollutants 

Outboard propulsion engine effluent samples were analyzed for 11 classical pollutants. 

Table 3.6.8 presents analytical results for the eight classical pollutants that were detected in one 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

291 

or more engine effluent samples. The detected results are also shown in Figure 3.6.10. EPA 

analyzed the sample results to determine which pollutants concentrations were contributed 

primarily by engine operations and which were contributed primarily by background ambient 

concentrations (see footnotes on table and figure). The remainder of this subsection discusses 

those pollutants found to be contributed primarily by engine operations. 

Temperature increases in engine effluent above background were less than 5°C for all 

vessels. Engine effluent temperatures were only slightly higher (approximately 1°C) when 

vessels were operated at higher power levels as compared to idling. 

Oil and grease (measured as HEM) was not detected in any of the engine effluent 

samples. SGT-HEM was detected in only two of 16 grab samples at concentrations significantly 

less than the reporting limit (sample concentrations of 0.86 mg/L and 0.94 mg/L, compared to 

reporting limit of 10 mg/L). 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.8. Results of Outboard Propulsion Engine Sample Analyses for Classical Pollutants1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Conductivity3 mS/cm 5 5 100 167 17 7.3 7.3 9.2 22 Dissolved Oxygen2 mg/L 5 5 100 6.2 6.3 5.7 5.7 5.9 6.4 pH2 SU 6 6 100 7.4 7.3 7.0 7.0 7.1 7.7 Salinity3 ppt 5 5 100 11 12 3.9 3.9 7.3 14 Silica Gel Treated HEM (SGT-HEM) mg/L 6 2 33 4.5 3.6 Temperature C 6 6 100 28 31 14 14 25 31 Total Suspended Solids (TSS) 3 mg/L 6 2 33 8.1 13 Turbidity2 NTU 6 6 100 13 10 6.5 6.5 8.0 21 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in ambient water. (3) Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background concentrations in ambient water. 

292 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

293 

Figure 3.6.10. Box and Dot Density Plot of Classical Pollutant Values Measured in Samples 

of Outboard Propulsion Engine Effluent

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

 

Con(mS/cm)**

DO (mg/l)*

SGT-H (mg/l)

Salin(ppt)**

TSS (mg/l)**

Temp. (C)

Turb (NTU)*

pH (SU)*

Classical Pollutant

5

10

15

20

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3.2.6.2.2 Metals 

Outboard propulsion engine effluent samples were analyzed for dissolved and total 

concentrations of 22 metals. Table 3.6.9 presents analytical results for the 14 metals that were 

detected in one or more engine effluent samples. The detected results are also shown in Figures 

3.6.11 and 3.6.12 for dissolved and total metals, respectively. Figures 3.6.13 and 3.6.14 display 

the distribution of PHQs based on the screening benchmark for each of the dissolved and total 

metals. EPA analyzed the sample results to determine which metals were contributed primarily 

by engine operations and which were contributed primarily by background ambient 

concentrations (see footnotes on table and figures). The remainder of this subsection discusses 

those metals found to be contributed primarily by engine operations. 

Dissolved and total concentrations for both vanadium and zinc are similar, which 

indicates that engine operations contribute these metals in dissolved rather that particulate form. 

Dissolved zinc was detected in all engine effluent samples at concentrations two to five times the 

reporting limit; none of the concentrations exceed the PHQ screening benchmark (a value of 81 

μg/L based on the chronic saltwater criterion for aquatic life). Dissolved vanadium was detected 

in engine effluent from four of the six sampled vessels at concentrations close to the reporting 

limit (<2 times reporting limit of 1 μg/L). Dissolved vanadium does not have an NRWQC or 

other PHQ screening benchmark. 

Total arsenic was detected in engine effluent from five of the six sampled vessels at 

concentrations two to five times the reporting limit (reporting limit = 8 μg/L), however, EPA 

suspects the measured concentrations of total (and dissolved) arsenic are elevated due to positive 

interference. Likewise, dissolved selenium was detected in all engine effluent samples at 

concentrations ranging from 2.4 to 100 μg/L; however, EPA suspects the measured 

concentrations of dissolved (and total) selenium are elevated due to positive interference. 

Finally, concentrations in engine effluent discharges for dissolved copper, total 

aluminum, total iron, and total manganese that exceed benchmark concentrations appear to be 

caused by background concentrations in ambient water and not by engine operations. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.9. Results of Outboard Propulsion Engine Sample Analyses for Metals1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Heavy and Other Metals

Aluminum, Dissolved2 μg/L 6 5 83 7.4 8.2 5.1 9.7 Aluminum, Total2 μg/L 6 6 100 160 58 34 34 38 320 Arsenic, Dissolved3,4 μg/L 6 5 83 25 32 8.6 37 Arsenic, Total3,4 μg/L 6 5 83 24 30 9.9 34 Barium, Dissolved2 μg/L 6 6 100 25 15 13 13 14 41 Barium, Total2 μg/L 6 6 100 27 16 14 14 14 43 Copper, Dissolved3 μg/L 6 6 100 3.3 3.4 2.8 2.8 3.1 3.5 Copper, Total3 μg/L 6 5 83 3.6 3.4 2.4 3.8 Iron, Total3 μg/L 6 2 33 200 460 Manganese, Dissolved2 μg/L 6 6 100 6.0 5.4 1.0 1.0 1.2 10 Manganese, Total3 μg/L 6 6 100 57 35 29 29 29 91 Nickel, Dissolved3 μg/L 6 6 100 5.6 6.6 3.2 3.2 3.6 7.1 Nickel, Total3 μg/L 6 6 100 11 7.7 3.3 3.3 5.6 14 Selenium, Dissolved3,4 μg/L 6 6 100 76 97 2.4 2.4 24 110 Selenium, Total3,4 μg/L 6 6 100 72 94 1.5 1.5 22 100 Vanadium, Dissolved μg/L 6 2 33 0.87 1.5 Vanadium,Total μg/L 6 3 50 1.7 1.2 1.4 Zinc, Dissolved3 μg/L 6 6 100 11 11 3.5 3.5 7.1 14 Zinc, Total μg/L 6 6 100 11 8.3 3.5 3.5 6.4 14 

Cationic Metals

Calcium, Dissolved3 μg/L 6 6 100 130000 160000 43000 43000 50000 17000Calcium, Total3 μg/L 6 6 100 130000 160000 43000 43000 51000 17000Magnesium, Dissolved3 μg/L 6 6 100 380000 480000 31000 31000 120000 52000

295 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

296 

Table 3.6.9. Results of Outboard Propulsion Engine Sample Analyses for Metals1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Magnesium, Total3 μg/L 6 6 100 370000 480000 31000 31000 120000 52000Potassium, Dissolved3 μg/L 6 6 100 130000 160000 11000 11000 48000 19000Potassium, Total3 μg/L 6 6 100 130000 160000 11000 11000 48000 18000Sodium, Dissolved3 μg/L 6 6 100 2900000 3800000 220000 220000 1000000 410000Sodium,Total3 μg/L 6 6 100 2900000 3700000 220000 220000 1100000 400000

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in ambient water. (3) Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background concentrations in ambient water. (4) Measured concentrations well above their respective reporting limits, are suspected of being elevated due to positive interference (See section 3.1.3)
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

297 

Figure 3.6.11. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Outboard Propulsion Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Measured concentrations well above their respective reporting limits for dissolved arsenic and selenium are 

suspected of being elevated due to positive interference). 

Aluminum*

Arsenic**

Barium*

Copper**

Manganese*

Nickel**

Selenium**

Vanadium

Zinc**

Dissolved Metals

1

10

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

298 

Figure 3.6.12. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Outboard Propulsion Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Measured concentrations well above their respective reporting limits for total arsenic and selenium are 

suspected of being elevated due to positive interference). 

Aluminum*

Arsenic**

Barium*

Copper**

Iron**

Manganese**

Nickel**

Selenium**

Vanadium

Zinc

Total Metals

1

10

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299 

Figure 3.6.13. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals 

in Samples of Outboard Propulsion Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Replacement values for non-detects are circled. Also, measured concentrations well above their respective 

reporting limits for dissolved arsenic and selenium are suspected of being elevated due to positive interference).

Aluminum*

Arsenic**

Barium*

Copper**

Manganese*

Nickel**

Selenium**

Vanadium

Zinc**

Dissolved Metals

0.10

1.00

10.00

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

300 

Figure 3.6.14. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Outboard Propulsion Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Replacement values for non-detects are circled. Also, measured concentrations well above their respective 

reporting limits for total arsenic and selenium are suspected of being elevated due to positive interference).

Aluminum*

Arsenic**

Barium*

Copper**

Iron**

Manganese**

Nickel**

Selenium**

Vanadium

Zinc

Total Metals

0.001

0.010

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10.000

100.000

1000.000

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301 

3.2.6.2.3 Semivolatile Organic Compounds 

Outboard propulsion engine effluent samples were analyzed for 62 SVOCs. Table 3.6.10 

presents analytical results for the seven SVOCs that were detected in one or more engine effluent 

samples. The detected results are also shown in Figure 3.6.15. EPA analyzed the sample results 

to determine which SVOCs were contributed primarily by engine operations and which were 

contributed primarily by background ambient concentrations. All were found to be contributed 

primarily by engine operations. 

The detected SVOCs can be classified among the following pollutant classes: polycyclic 

aromatic hydrocarbons (PAHs) (one analyte), phenol and methyl phenols (four analytes), 

phthalates (one analyte), and methylnaphthalenes (one analyte). All of these SVOCs were 

frequently detected in engine effluent (i.e., more than half of the sampled vessels). However, all 

of the detected SVOC concentrations are well below any applicable PHQ screening benchmarks. 

For example, the maximum PHQ for any of the detected SVOCs was 2,4-dimethylphenol with a 

PHQ of approximately 0.005. Therefore, SVOCs in engine effluent are highly unlikely to have 

the potential to pose risk to human health or the environment.
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.10. Results of Outboard Propulsion Engine Sample Analyses for SVOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

2,4-Dimethylphenol μg/L 6 1 17 2.5 0.49 2-Methylnaphthalene μg/L 6 2 33 2.4 1.5 Di-n-butyl phthalate μg/L 6 3 50 2.4 1.2 2.3 m-Cresol μg/L 6 2 33 2.6 1.9 Naphthalene μg/L 6 5 83 7.8 2.0 1.4 12 p-Cresol μg/L 6 2 33 3.7 3.9 Phenol μg/L 6 2 33 4.6 5.9 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. 

302 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

303 

Figure 3.6.15. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Outboard Propulsion Engine Effluent 

(Note: two analyte names were truncated: 2-Methylnaphalene and Di-n-butyl phthalate). 

2,4-Dimethyl

2-Methylnaph

Di-n-butyl p

Naphthalene

Phenol

m-Cresol

p-Cresol

SVOCs

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20

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.2.4 Volatile Organic Compounds 

Outboard propulsion engine effluent samples were analyzed for 70 VOCs. Table 3.6.11 

presents analytical results for the 18 VOCs that were detected in one or more engine effluent 

samples. The detected results are also shown in Figures 3.6.16 and 3.6.17 for analyte 

concentrations and for PHQs based on the lowest NRWQC or other PHQ screening benchmark 

where applicable, respectively. EPA analyzed the sample results to determine which VOCs were 

contributed primarily by engine operations and which were contributed primarily by background 

ambient concentrations. All were found to be contributed primarily by engine operations. Some 

of these compounds are volatile constituents of fuel, specifically benzene, toluene, ethylbenzene, 

and xylene. Others are trimethylbenzenes, which are naturally present in fuel, and one is a 

ketone, which may be formed as a product of incomplete combustion. Among these compounds, 

benzene, ethylbenzene, and toluene have an NRWQC. Most of the detected benzene 

concentrations exceeded the PHQ screening benchmark of 2.2 μg/L (human heath for 

consumption of water and aquatic organisms), including discharges from the two research 

vessels that exceed the benchmark by factors of five and 28. None of the detected ethylbenzene 

and toluene concentrations exceeded the PHQ screening benchmarks. 

The final one-third of the detected VOCs were detected relatively infrequently (i.e., 

detected in fewer than half the sampled vessels). Among these compounds, only methylene 

chloride has an NRWQC. However, none of the detected methylene chlorine concentrations 

exceeded the screening benchmark. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.11. Results of Outboard Propulsion Engine Sample Analyses for VOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. 2 Median Conc. Minimum Conc. 10% 25% 75% 

1,2,4-Trimethylbenzene μg/L 6 6 100 13 2.3 0.30 0.30 0.53 24 1,3,5-Trimethylbenzene μg/L 6 5 83 4.6 1.9 0.75 6.5 2-Butanone μg/L 6 2 33 3.8 3.8 2-Hexanone μg/L 6 1 17 2.5 0.56 4-Methyl-2-Pentanone μg/L 6 1 17 2.3 0.35 Acetone μg/L 6 5 83 7.8 2.5 1.4 11 Benzene μg/L 6 6 100 13 2.4 0.13 0.13 0.76 24 Cyclohexane μg/L 6 1 17 2.4 0.41 Ethylbenzene μg/L 6 6 100 8.2 2.1 0.90 0.90 0.92 14 Isopropylbenzene μg/L 6 2 33 2.4 1.3 m-,p-Xylene (sum of isomers) μg/L 6 6 100 28 3.4 0.33 0.33 0.43 52 Methyl tertiary butyl ether (MTBE) μg/L 6 1 17 2.3 0.34 Methylcyclohexane μg/L 6 1 17 2.3 0.36 Methylene chloride μg/L 6 5 83 0.58 0.20 0.15 0.20 n-Propylbenzene μg/L 6 4 67 3.2 1.7 3.6 O-Xylene μg/L 6 6 100 15 4.0 0.17 0.17 0.43 26 Styrene μg/L 6 5 83 4.9 3.4 0.22 6.6 Toluene μg/L 6 6 100 52 3.8 0.40 0.40 0.75 98 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) In some cases, the detected concentration(s) for an analyte could be lower than the replacement value (1⁄2 of the reporting limit) for a concentration tha

extreme (but possible) case, this could result in an average concentration for an analyte that is greater than the maximum detected concentration. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

306 

Figure 3.6.16. Box and Dot Density Plot of Volatile Organic Compounds Concentrations 

Measured in Samples of Outboard Propulsion Engine Effluent 

VOCs are identified as follows: 

(1) 1,2,4-Trimethylbenzene 

(2) 1,3,5-Trimethylbenzene 

(3) 2-Butanone 

(4) 2-Hexanone 

(5) 4-Methyl-2-Pentanone 

(6) Acetone 

(7) Benzene 

(8) Cyclohexane 

(9) Ethylbenzene 

(10) Isopropylbenzene 

(11) m-,p-Xylene (sum of 

isomers) 

(12) Methyl tertiary butyl ether 

(MTBE) 

(13) Methylcyclohexane 

(14) Methylene chloride 

(15) n-Propylbenzene 

(16) O-Xylene 

(17) Styrene 

(18) Toluene 

0 2 4 6 8 10 12 14 16 18 20

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307 

Figure 3.6.17. Box and Dot Density Plot of Potential Hazard Quotients for Volatile Organic 

Compounds in Samples of Outboard Propulsion Engine Effluent 

VOCs are identified as follows (replacement values for non-detects are circled): 

(1) 1,2,4-Trimethylbenzene 

(2) 1,3,5-Trimethylbenzene 

(3) 2-Butanone 

(4) 2-Hexanone 

(5) 4-Methyl-2-Pentanone 

(6) Acetone 

(7) Benzene 

(8) Cyclohexane 

(9) Ethylbenzene 

(10) Isopropylbenzene 

(11) m-,p-Xylene (sum of 

isomers) 

(12) Methyl tertiary butyl ether 

(MTBE) 

(13) Methylcyclohexane 

(14) Methylene chloride 

(15) n-Propylbenzene 

(16) O-Xylene 

(17) Styrene 

(18) Toluene 

10.000

0 2 4 6 8 10 12 14 16 18 20

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.3 Generator Engines 

For this study, EPA collected cooling water discharge samples from engines on generator 

sets onboard five vessels: a fishing vessel, a fire boat, two tour boats, and a water taxi (Table 

3.6.1). These engines included both direct and indirect cooling discharges from both gasolineand diesel-fueled engines. 

The Generator on a Fire Boat 

3.2.6.3.1 Classical Pollutants 

Table 3.6.12 presents analytical results for 11 classical pollutants detected in samples of 

discharges from generator engines (all classical pollutants analyzed for were detected). The 

detected results are also shown in Figure 3.6.18. EPA analyzed the sample results to determine 

which pollutant concentrations were contributed primarily by generator engine operations and 

which were contributed primarily by background ambient concentrations (see footnotes on table 

and figure). The remainder of this subsection discusses those classical pollutants found to be 

contributed primarily by generator engine operations. 

Temperature increases in generator engine effluent above background were 

approximately 5°C for the fishing vessel, fire boat, and water taxi. For the two tour boats, 

temperature increases were 9 and 13°C. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

309 

Oil and grease (measured as HEM) was detected in engine effluent from three of the five 

sampled generators; however, detected concentrations were low, ranging from less than the 

reporting limit to just above the reporting limit (reporting limit = 5 mg/L). All sample results 

were well below the 33 CFR Part 151.10 prohibition of the discharge of oil and oily mixtures 

with an oil content greater than 15 ppm into seawater from vessels. 

Sulfide was detected in only one of five samples at a concentration of 0.012 mg/L, which 

is slightly above the reporting limit of 0.01 mg/L. This concentration is six times greater than the 

most conservative PHQ screening benchmark – a 2006 NRWQC value of 0.002 mg/L for the 

protection of aquatic life. Sulfide could be present due to entrainment in fuel, as a product of 

incomplete combustion, or due to formation within the biofilm in the cooling system piping. 

TRC was detected in only one generator engine effluent sample collected from a water 

taxi at a concentration of 0.15 mg/L. This detected concentration is 20 times greater than the 

PHQ screening benchmark of 0.0075 mg/L. There is no known source of TRC for this vessel as 

background concentration of the ambient water at this location was below detection and the 

generator did not use service water that might contain TRC. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.12. Results of Generator Engine Sample Analyses for Classical Pollutants1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. 4 Median Conc. Minimum Conc. 10% 25% 75% 

Conductivity2 mS/cm 4 4 100 11 0.31 0.23 0.23 0.23 32 Dissolved Oxygen2 mg/L 4 4 100 5.3 6.2 1.9 1.9 2.6 7.7 Hexane Extractable Material (HEM) mg/L 5 3 60 2.9 1.1 4.3 pH2 SU 5 5 100 6.5 6.6 5.7 5. 7 5.9 7.0 Salinity3 ppt 4 4 100 6.5 0.20 0.10 0.10 0.10 19 Silica Gel Treated HEM (SGT-HEM) mg/L 5 1 20 4.2 0.55 Sulfide mg/L 4 1 25 0.0068 0.0090 Temperature C 5 5 100 21 20 18 18 19 24 Total Residual Chlorine mg/L 5 1 20 0.060 0.075 Total Suspended Solids (TSS) 3 mg/L 4 3 75 9.0 12 2.1 13 Turbidity2 NTU 5 5 100 27 33 1.3 1.3 14 38 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in ambient water. (3) Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background concentrations in ambient water. (4) In some cases, the detected concentration(s) for an analyte could be lower than the replacement value (1⁄2 of the reporting limit) for a concentration tha

extreme (but possible) case, this could result in an average concentration for an analyte that is greater than the maximum detected concentration. 

310 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

311 

Figure 3.6.18. Box and Dot Density Plot of Classical Pollutant Values Measured in Samples 

of Generator Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

Cond(mS/cm)*

DO (mg/l)*

HEM (mg/l)

SGT-H (mg/l)

Salin(ppt)**

Sulf. (mg/l)

TRC (mg/l)

TSS (mg/l)**

Temp. (C)

Turb.(NTU)*

pH (SU)*

Classical Pollutants

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312 

3.2.6.3.2 Metals 

Generator engine effluent samples were analyzed for dissolved and total concentrations 

of 22 metals. Table 3.6.13 presents analytical results for the 11 metals that were detected. The 

detected results are also shown in Figures 3.6.19 and 3.6.20 for dissolved and total metals, 

respectively. Figures 3.6.21 and 3.6.22 display the distribution of PHQs based on the screening 

benchmark for each of the dissolved and total metals. EPA analyzed the sample results to 

determine which metals were contributed primarily by generator engine operations and which 

were contributed primarily by background ambient concentrations (see footnotes on table and 

figures). The remainder of this subsection discusses those metals found to be contributed 

primarily by generator engine operations. 

Dissolved and total metals concentrations are similar, which indicates that engine 

operations contribute metals in dissolved rather that particulate form. Dissolved copper was 

detected in all five generator effluent samples at concentrations ranging from 2.4 to 13 μg/L. 

Total copper was detected in two of the five samples at concentrations of 2.4 and 11 μg/L 

(reporting limit = 5 μg/L). Dissolved copper concentrations exceeded the PHQ screening 

benchmark of 3.1 μg/L (2006 NRWQC saltwater chronic aquatic life criterion) by as much as 

five times. In contrast, none of the total copper concentrations exceeded the PHQ screening 

benchmark of 1,300 μg/L (human health criterion based on consumption of water and aquatic 

organisms). 

Dissolved manganese was detected in four of the five generator engine effluent samples. 

Manganese was predominantly in particulate form in background ambient water; therefore, 

dissolved manganese concentrations in engine effluent samples are assumed to be contributed by 

engine operations. NRWQCs or other PHQ screening benchmarks have not been determined for 

dissolved manganese. 

Dissolved zinc was detected in two of the five generator engine effluent samples. 

Detected concentrations were 21 to 29 μg/L, which are substantially lower than the screening 

benchmark of 81 μg/L (2006 NRWQC saltwater chronic aquatic life criterion). 

Finally, concentrations in generator engine effluent discharges that exceed benchmark 

concentrations for total aluminum are likely caused or heavily influenced by higher 

concentrations in ambient water (which exceeded benchmark concentrations). 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.13. Results of Generator Engine Sample Analyses for Metals1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. 4 Median Conc. Minimum Conc. 10% 25% 75% 

Heavy and Other Metals 

Aluminum, Dissolved2 μg/L 5 5 100 280 160 11 11 86 540 Aluminum, Total2 μg/L 5 5 100 420 390 120 120 220 640 Barium, Dissolved2 μg/L 1 1 100 37Barium, Total2 μg/L 1 1 100 37Copper, Dissolved μg/L 5 5 100 6.5 5.6 2.4 2.4 3.9 9.5 Copper, Total μg/L 5 2 40 4.2 6.7 Iron, Total2 μg/L 1 1 100 200 Manganese, Dissolved μg/L 5 4 80 33 36 16 49 Manganese, Total3 μg/L 5 4 80 40 43 17 59 Nickel, Dissolved3 μg/L 5 1 20 4.5 1.4 Nickel, Total3 μg/L 5 1 20 3.5 1.4 Zinc, Dissolved μg/L 5 2 40 13 25 Zinc, Total3 μg/L 5 3 60 11 12 15 

Cationic Metals 

Calcium, Dissolved2 μg/L 5 5 100 80000 26000 23000 23000 24000 16000Calcium, Total2 μg/L 5 5 100 82000 28000 27000 27000 27000 16000Magnesium, Dissolved2 μg/L 5 5 100 180000 5900 5200 5200 5200 44000Magnesium, Total2 μg/L 5 5 100 180000 6600 5900 5900 5950 45000Potassium, Dissolved2 μg/L 1 1 100 4000 Potassium, Total2 μg/L 1 1 100 3600 Sodium, Dissolved2 μg/L 1 1 100 37000 Sodium,Total2 μg/L 1 1 100 36000 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in ambient water. (3) Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background concentrations in ambient water. (4) In some cases, the detected concentration(s) for an analyte could be lower than the replacement value (1⁄2 of the reporting limit) for a concentration tha

extreme (but possible) case, this could result in an average concentration for an analyte that is greater than the maximum detected concentration. 

313 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

314 

Figure 3.6.19. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Generator Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

Aluminum*

Barium*

Copper

Manganese

Nickel**

Zinc

Dissolved Metals

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

315 

Figure 3.6.20. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Generator Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

Aluminum*

Barium*

Copper

Iron*

Manganese**

Nickel**

Zinc**

Total Metals

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Aluminum*

Barium*

Copper

Manganese

Nickel**

Zinc

Dissolved Metals

1

2

3

4

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Figure 3.6.21. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals 

in Samples of Generator Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Replacement values for non-detects are circled). 

316 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Aluminum*

Barium*

Copper

Iron*

Manganese**

Nickel**

Zinc**

Total Metals

0.001

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1.000

10.000

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Samples of Generator Engine Effluent 

* Sample concentrations were almost completely accounted for (≥ 90 percent) by background concentrations in 

ambient water. 

** Sample concentrations were predominantly accounted for (≥ 50 percent and <90 percent) by background 

concentrations in ambient water. 

(Note: Replacement values for non-detects are circled). 

317 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.3.3 Semivolatile Organic Compounds 

Generator engine effluent samples were analyzed for 79 SVOCs. Table 3.6.14 presents 

analytical results for the 26 SVOCs that were detected in one or more engine effluent samples 

(14 of the detected SVOCs were analyzed for and detected in only one generator effluent 

sample). The detected results are shown in Figures 3.6.23 and 3.6.24 for analyte concentrations 

and PHQs based on the lowest applicable NRWQC or other PHQ screening benchmark. EPA 

analyzed the sample results to determine which SVOCs were contributed primarily by generator 

engine operations and which were contributed primarily by background ambient concentrations. 

All were found to be contributed primarily by generator engine operations. 

Many of the detected SVOCs can be classified among the following pollutant classes: 

PAHs (five analytes), straight-chain hydrocarbons (six analytes), phenol and methyl phenols 

(five analytes), and phthalates (two analytes). These include all of the SVOCs analyzed for and 

detected most frequently and at the highest concentrations. 

PAHs are present in fuels in small amounts and may be formed as products of incomplete 

combustion. However, none of the detected PAH concentrations exceeded the screening 

benchmarks for these analytes, indicating that they are unlikely to have the potential to pose risk 

to human health or the environment. 

Straight-chain (alkane) hydrocarbons are also components of fuel. None of these analytes 

has an NRWQC or other PHQ screening benchmark, and they are not PBT chemicals. Therefore, 

the straight-chain hydrocarbons detected in engine effluent are unlikely to have the potential to 

pose risk to human health or the environment. 

Phenol and methyl phenols are also present in petroleum products and may also be 

generated as products of incomplete combustion. Discharges of phenol and methyl phenols are 

assumed not to result in any environmental impacts as detected concentrations did not exceed the 

screening benchmarks for these analytes. 

Phthalates are plasticizers (chemicals added to plastics to make them flexible) and are 

commonly detected in environmental samples (ATSDR, 2002). Bis(2-ethylhexyl) phthalate was 

detected at concentration just above the screening benchmark of 1.2 μg/L (human heath for 

consumption of water and aquatic organisms). 

The generator engine effluent sample from the fire boat contained the maximum 

concentration of 12 of the detected SVOCs. These include all five of the detected PAHs, four of 

the five detected phenols and methyl phenols, and both of the detected phthalates. The generator 

effluent sample from a tour boat contained the maximum concentration of all six of the detected 

straight-chain hydrocarbons. 

318 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.14. Results of Generator Engine Sample Analyses for SVOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. 2 Median Conc. Minimum Conc. 10% 25% 75% 

1-methylnaphthalene μg/L 3 3 100 6.7 5.4 3.8 3.8 3.8 11 2,4-Dimethylphenol μg/L 5 1 20 2.6 4.0 2-Cyclopenten1-one μg/L 2 2 100 8.5 13 3.9 3.9 3.9 13 2-Hydroxy-Benzaldehyde μg/L 2 2 100 11 17 4.3 4.3 4.3 17 2-Methylnaphthalene μg/L 4 4 100 16 10 4.6 4.6 5.5 32 2-Naphthalene μg/L 2 2 100 18 20 16 16 16 20 3-Methyl-Benzaldehyde μg/L 1 1 100 18 3-Methylphenol μg/L 1 1 100 12 3-Phenyl-2-Propenal μg/L 1 1 100 8.1 Acenaphthylene μg/L 5 1 20 1.8 1.9 Acetophenone μg/L 1 1 100 11 Bis(2-ethylhexyl) phthalate μg/L 5 1 20 1.3 0.63 Di-n-butyl phthalate μg/L 5 1 20 1.3 0.59 Eicosane μg/L 1 1 100 32 Fluorene μg/L 5 1 20 2.0 2.4 Heneicosane μg/L 1 1 100 22 Heptadecane μg/L 3 3 100 30 8.9 4.1 4.1 4.1 76 m-Cresol μg/L 1 1 100 18 Naphthalene μg/L 5 4 80 17 7.3 2.3 36 n-Hexadecane μg/L 1 1 100 46 Nonadecane μg/L 1 1 100 40 Octadecane μg/L 1 1 100 44 p-Cresol μg/L 1 1 100 43 

319 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

320 

Table 3.6.14. Results of Generator Engine Sample Analyses for SVOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. 2 Median Conc. Minimum Conc. 10% 25% 75% 

Phenanthrene μg/L 5 3 60 3.9 3.2 6.8 Phenol μg/L 5 4 80 23 13 2.1 48 Pyrene μg/L 5 1 20 1.4 0.90 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) In some cases, the detected concentration(s) for an analyte could be lower than the replacement value (1⁄2 of the reporting limit) for a concentration tha

extreme (but possible) case, this could result in an average concentration for an analyte that is greater than the maximum detected concentration. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

321 

Figure 3.6.23. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Generator Engine Effluent 

SVOCs are identified as follows: 

(1) 1-methylnaphthalene 

(2) 2,4-Dimethylphenol 

(3) 2-Cyclopenten1-one 

(4) 2-Hydroxy-Benzaldehyde 

(5) 2-Methylnaphthalene 

(6) 2-

Naphthalenecarboxaldehyde 

(7) 3-Methyl-Benzaldehyde 

(8) 3-Methylphenol 

(9) 3-Phenyl-2-Propenal 

(10) Acenaphthylene 

(11) Acetophenone 

(12) Bis(2-ethylhexyl) phthalate 

(13) Di-n-butyl phthalate 

(14) Eicosane 

(15) Fluorene 

(16) Heneicosane 

(17) Heptadecane 

(18) m-Cresol 

(19) Naphthalene 

(20) n-Hexadecane 

(21) Nonadecane 

(22) Octadecane 

(23) p-Cresol 

(24) Phenanthrene 

(25) Phenol 

(26) Pyrene

0 2 4 6 8 10 12 14 16 18 20 22 24 26

SVOCs

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322 

Figure 3.6.24. Box and Dot Density Plot of Potential Hazard Quotients for SVOCs in 

Samples of Generator Engine Effluent 

SVOCs are identified as follows (replacement values for non-detects are circled): 

(1) 1-methylnaphthalene 

(2) 2,4-Dimethylphenol 

(3) 2-Cyclopenten1-one 

(4) 2-Hydroxy-Benzaldehyde 

(5) 2-Methylnaphthalene 

(6) 2-Naphthalenecarboxaldehyde 

(7) 3-Methyl-Benzaldehyde 

(8) 3-Methylphenol 

(9) 3-Phenyl-2-Propenal 

(10) Acenaphthylene 

(11) Acetophenone 

(12) Bis(2-ethylhexyl) phthalate 

(13) Di-n-butyl phthalate 

(14) Eicosane 

(15) Fluorene 

(16) Heneicosane 

(17) Heptadecane 

(18) m-Cresol 

(19) Naphthalene 

(20) n-Hexadecane 

(21) Nonadecane 

(22) Octadecane 

(23) p-Cresol 

(24) Phenanthrene 

(25) Phenol 

(26) Pyrene 

0 2 4 6 8 10 12 14 16 18 20 22 24 26

SVOCs

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3.2.6.3.4 Volatile Organic Compounds 

Generator engine effluent samples were analyzed for 80 VOCs. Table 3.6.15 presents 

analytical results for the 28 VOCs that were detected. The detected results are also shown in 

Figures 3.6.25 and 3.6.26 for analyte concentrations and for PHQs based on the lowest NRWQC 

or other PHQ screening benchmark, where applicable, respectively. EPA analyzed the sample 

results to determine which VOCs were contributed primarily by generator engine operations and 

which were contributed primarily by background ambient concentrations. All were found to be 

contributed primarily by generator engine operations. 

Twenty-two of the detected VOCs were analyzed for in only one sample. None of these 

compounds has an NRWQC or are PBT chemicals. Of the seven detected VOCs that were 

analyzed for in more than one sample, three have an NRWQC: benzene, ethylbenzene, and 

toluene. All of the detected benzene concentrations (from three of the five samples) exceeded the 

PHQ screening benchmark of 2.2 μg/L by factors ranging from one to nine. The single detected 

concentration for each of ethylenebenzene and toluene did not exceed their respective PHQ 

screening benchmarks. 

Note that the generator effluent sample from the fire boat contained the maximum 

concentration of 19 of the detected VOCs. These include benzene, toluene, ethylbenzene, xylene, 

trimethylbenzenes, and ketones. 

323 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.15. Results of Generator Engine Sample Analyses for VOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

(E)-2-Butenal μg/L 1 1 100 12 1,2,3,4-Tetrahydro-5-Methylnaphthalene μg/L 1 1 100 5.9 1,2,3,4-Tetrahydro-6-Methylnaphthalene μg/L 1 1 100 7.2 1,2,4-Trimethylbenzene μg/L 1 1 100 8.0 1,3,5-Trimethylbenzene μg/L 1 1 100 1.6 2,6-Dimethyl μg/L 1 1 100 5.5 2-Butanone μg/L 1 1 100 832-Butenal μg/L 1 1 100 192-Ethyl-1,4-DimethylBenzene μg/L 1 1 100 5.7 4-Isopropyltoluene μg/L 1 1 100 0.40 4-Methyl-2-Pentanone μg/L 1 1 100 1.7 Acetone μg/L 2 2 100 120 220 22 22 22 220 Benzaldehyde μg/L 1 1 100 4.2 Benzene μg/L 5 3 60 5.9 3.1 12 Benzofuran μg/L 1 1 100 6.9 Biphenyl μg/L 1 1 100 12 Ethylbenzene μg/L 5 1 20 1.4 1.0 Isopropylbenzene μg/L 1 1 100 0.50 m-,p-Xylene (sum of isomers) μg/L 1 1 100 5.3 Methyl acetate μg/L 1 1 100 0.80 n-Pentadecane μg/L 1 1 100 40n-Propylbenzene μg/L 1 1 100 0.90 n-Tetradecane μg/L 1 1 100 20O-Xylene μg/L 1 1 100 3.4 sec-Butylbenzene μg/L 1 1 100 0.50 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human 

325 

Table 3.6.15. Results of Generator Engine Sample Analyses for VOCs 1

Analyte Units No. Samples No. Detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 75% 

Styrene μg/L 1 1 100 8.9 Toluene μg/L 5 1 20 3.5 6.2 Vinyl acetate μg/L 1 1 100 1.5 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

326 

Figure 3.6.25. Box and Dot Density Plot of VOC Concentrations Measured in Samples of 

Generator Engine Effluent 

VOCs are identified as follows: 

(1) (E)-2-Butenal 

(2) 1,2,3,4-Tetrahydro-5-

Methylnaphthalene 

(3) 1,2,3,4-Tetrahydro-6-

Methylnaphthalene 

(4) 1,2,4-Trimethylbenzene 

(5) 1,3,5-Trimethylbenzene 

(6) 2,6-dimethylnaphthalene 

(7) 2-Butanone 

(8) 2-Butenal 

(9) 2-Ethyl-1,4-DimethylBenzene 

(10) 4-Isopropyltoluene 

(11) 4-Methyl-2-Pentanone 

(12) Acetone 

(13) Benzaldehyde 

(14) Benzene 

(15) Benzofuran 

(16) Biphenyl 

(17) Ethylbenzene 

(18) Isopropylbenzene 

(19) m-,p-Xylene (sum of 

isomers) 

(20) Methyl acetate 

(21) n-Pentadecane 

(22) n-Propylbenzene 

(23) n-Tetradecane 

(24) o-Xylene 

(25) sec-Butylbenzene 

(26) Styrene 

(27) Toluene 

(28) Vinyl acetate

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

VOCs

1

10

100

C

o

n

c

e

ntr

atio

n (u

g

/

L)
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

10.00

327 

Figure 3.6.26. Box and Dot Density Plot of Potential Hazard Quotients for VOCs in 

Samples of Generator Engine Effluent 

VOCs are identified as follows (replacement values for non-detects are circled): 

(1) (E)-2-Butenal 

(2) 1,2,3,4-Tetrahydro-5-

Methylnaphthalene 

(3) 1,2,3,4-Tetrahydro-6-

Methylnaphthalene 

(4) 1,2,4-Trimethylbenzene 

(5) 1,3,5-Trimethylbenzene 

(6) 2,6-dimethylnaphthalene 

(7) 2-Butanone 

(8) 2-Butenal 

(9) 2-Ethyl-1,4-DimethylBenzene 

(10) 4-Isopropyltoluene 

(11) 4-Methyl-2-Pentanone 

(12) Acetone 

(13) Benzaldehyde 

(14) Benzene 

(15) Benzofuran 

(16) Biphenyl 

(17) Ethylbenzene 

(18) Isopropylbenzene 

(19) m-,p-Xylene (sum of 

isomers) 

(20) Methyl acetate 

(21) n-Pentadecane 

(22) n-Propylbenzene 

(23) n-Tetradecane 

(25) sec-Butylbenzene 

(26) Styrene 

(27) Toluene 

(28) Vinyl acetate

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28

VOCs

0.00

0.01

0.10

1.00

P

ote

ntial H

a

z

a

r

d

Q

u

otie

nt
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.4 Comparison of Effluent Generated at Different Propulsion Engine Power 

Levels 

Although inboard and outboard propulsion engines were often sampled during operation 

at different power levels (e.g., idle, half power, full power), these samples were generally 

composited for a single analysis. Exceptions include samples for analysis of HEM/SGT-HEM 

and VOCs, which were collected and analyzed separately for each power level of engine 

operation (composite samples for these analytes are not appropriate). EPA reviewed the 

HEM/SGT-HEM and VOC data to determine whether there were any trends in the resulting data 

based on engine power level of operation. 

HEM was detected in the majority of inboard engine effluent samples; however, detected 

concentrations were low (the majority were less than the reporting limit of 5 mg/L). Of the eight 

vessels with inboard engines with detected HEM concentrations that were sampled at different 

power levels, engine effluent samples from six had higher HEM concentrations at higher engine 

levels than at idle. Data for the remaining two vessels were inconclusive. Note, however, that 

differences in HEM concentrations among power levels were small, ranging from 0.1 to 5 mg/L. 

For outboard engines, HEM was not detected in any of the engine effluent samples. 

Regarding VOC results for inboard engines, EPA reviewed benzene, toluene, 

ethylbenzene, and xylene concentrations as these compounds were the most frequently detected. 

Of the eight vessels with inboard engines with detected benzene concentrations that were 

sampled at different power levels, engine effluent samples from five contained higher benzene 

concentrations at higher engine levels than at idle. Data for the remaining three vessels showed 

the opposite pattern, with higher benzene concentrations at idle than at higher engine levels. For 

seven of these sampled vessels, differences in benzene concentrations among the power levels 

were small, ranging from 0.1 to 4.7 μg/L. In contrast, for the remaining vessel (a recreational 

vessel), the difference in benzene concentrations from idle to three-quarter speed was 89 μg/L, 

with the higher concentration detected at idle. As discussed previously, this recreational vessel 

was the only sampled vessel that used gasoline as fuel rather than diesel. In addition, the engines 

on this vessel were dewinterized immediately prior to sampling. 

The differential among detected concentrations of ethylbenzene, xylene, and toluene at 

different power levels is too small to draw any conclusions, except for the engine effluent data 

for the recreational vessel. Differences in detected concentrations between idle and three-quarter 

power were 18 μg/L for ethylbenzene, 73 μg/L for m-,p-xylene, 31 μg/L for o-xylene, and 84 

μg/L for toluene. The higher concentrations were found at idle for all four analytes. 

The UNDS sampling program provides a useful comparison for this study as it was 

specifically designed to evaluate engine wet exhaust characteristics among power levels, 

including the separate collection and analysis of three replicate samples at each of five different 

328 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

329 

power levels. Tables 3.6.16 and 3.6.17 present sample results from the UNDS study by power 

level for the LCPL and RIB, respectively. 

EPA made several conclusions for the LCPL based on a review of the engine effluent 

results. Chromium, copper, lead, and nickel were all detected at concentrations significantly 

greater than background concentrations for all five power levels. For copper and nickel, 

concentrations were highest at idle, second highest at 100 percent power, and then generally 

decreased with decreasing power levels (decreasing engine RPM). Chromium concentrations 

were highest at 100 percent power and then also decreased with decreasing power levels, with 

the lowest chromium concentrations found at idle. Lead concentrations were not significantly 

different at the various power levels. For TOC and phenol, only idle concentrations were 

significantly greater than background concentrations. 

For the RIB, only TOC concentrations were significantly greater than background 

concentrations for all five power levels. TOC concentrations were highest at 100 power and then 

generally decreased with decreasing power levels; TOC concentrations were lowest at idle. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.16. Mean Concentration Results, UNDS Engine Wet Exhaust Discharge and Background Sampl

Mode 1 

RPM 2050 

(100% Power) 

Mode 2 

RPM 1850 

(75% Power) 

Mode 3 

RPM 1650 

(50% Power) 

Mode 4 

RPM 1300 

(25% Power) 

Mode 5 

RPM 750 

(0% Power) 

B

Analyte 

Mean Mean Mean Mean Mean 

Classical Parameters Nitrate/Nitrite (NO2 + NO3-N) ND (0.010) 0.011 0.011 ND (0.010) 0.012 Total Organic Carbon (TOC) 1.15 1.03 0.933 0.858 1.73 Metals Arsenic, Total 2.22 1.98 1.92 2.38 2.21 Cadmium, Total 0.032 0.028 0.024 0.022 0.022 Chromium, Total 0.574 0.431 0.313 0.310 0.260 Copper, Total 21.7 26.0 17.2 13.5 40.1 Lead, Total 0.369 0.188 0.145 0.118 0.127 Nickel, Total 4.12 4.79 3.04 2.81 14.8 SVOCs Bis(2-ethylhexyl)phthalate ND (10.0) ND (10.0) ND (10.18) ND (10.0) 20.4 Phenol ND (10.0) ND (10.0) ND (10.18) ND (10.0) 19.7 

Source: USEPA, 2008b. (1) Mean values were estimated based on the replicate concentrations for each mode or background sample using a lognormal or modified-delta lognorm

ND – Not detected (number in parentheses is reporting limit). 

330 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

331 

Table 3.6.17. Mean Concentration Results, UNDS Engine Wet Exhaust Discharge and Background Sampl

Mode 1 

RPM 2450 

(100% Power) 

Mode 2 

RPM 2270 

(75% Power) 

Mode 3 

RPM 1720 

(50% Power) 

Mode 4 

RPM 1290 

(25% Power) 

Mode 5 

RPM 400 

(0% Power) 

Analyte 

Mean Mean Mean Mean Mean 

Classical Parameters Biochemical Oxygen Demand (BOD) ND (2.00) ND (2.00) ND (2.00) 4.8 3.3 Nitrate/Nitrite (NO2 + NO3-N) 0.017 ND (0.010) 0.015 0.012 0.013 Total Organic Carbon (TOC) 1.67 1.55 1.27 1.15 1.29 Total Suspended Solids (TSS) 11.9 12.4 ND (5.00) 5.3 ND (5.00) SVOCs Phenol 32.4 24.6 ND (10.0) ND (10.0) ND (10.0) VOCs1,2,3-Trimethylbenzene 12.3 ND (10.0) ND (10.0) ND (10.0) 12.6 1,3,5-Trimethylbenzene 12.3 ND (10.0) ND (10.0) ND (10.0) 12.6 

Source: USEPA, 2008b. (1) Mean values were estimated based on the replicate concentrations for each mode or background sample using a lognormal or modified-delta lognorm

ND – Not detected (number in parentheses is reporting limit). 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.5 Engine Dewinterizing Effluent 

Marine engines used in cold climates typically require maintenance prior to winter 

storage to prevent engine damage caused by freezing or corrosion. The indirect cooling systems 

in inboard engines are typically winterized by draining the water from the ambient water cooling 

system and refilling the system with approximately 5 gallons of antifreeze. Marine engine 

antifreeze contains propylene glycol37, corrosion inhibitors, and other additives. In spring, the 5 

gallons of antifreeze is emptied by starting the engine, which discharges the glycol solution and 

replaces it with ambient water. EPA sampled dewinterizing effluent from an inboard engine on a 

recreational vessel as it was converted from winter storage. This sample was collected in the 

same manner as that used for sampling other engine effluents. The sample was analyzed for 

select classical pollutants and metals. 

Table 3.6.18 presents the collected dewinterizing effluent data, together with the mean 

inboard propulsion engine effluent concentrations from Tables 3.6.2 and 3.6.3. The source of the 

biochemical oxygen demand concentrations is the propylene glycol in the antifreeze. Elevated 

metals concentrations in dewinterizing effluent compared to those in inboard engine effluent 

could have been due to prolonged contact of the antifreeze with the engine cooling system and 

associated piping. 

Outboard engines are winterized by spraying an oily aerosol, commonly referred to as 

“fog,” into the combustion air intake while the motor is running. Therefore, the engine 

dewinterizing effluent sample results in this subsection are not applicable to outboard engines. 

 

37 Ethylene glycol is not used for marine applications due to its higher toxicity as compared to propylene glycol. 

332 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

333 

Table 3.6.18. Comparison of Dewinterizing Effluent with Propulsion Effluent 

Analyte Units Dewinterizing Effluent Inboard Propulsion Engine Mean Concentration 

from Tables 3.6.2 and 3.6.3

Classical Parameters 

Biochemical Oxygen Demand 

(BOD) mg/L 11 Not analyzed 

Total Residual Chlorine mg/L 2.8 0.0481

Turbidity NTU 350 322

Metals 

Aluminum, Dissolved μg/L 560 2001

Aluminum, Total μg/L 3,700 3401

Antimony, Dissolved μg/L 2.1 Not detected 

Antimony, Total μg/L 2.4 Not detected 

Arsenic, Dissolved μg/L 24 4.22,4

Arsenic, Total μg/L 32 4.52,4

Barium, Dissolved μg/L 43 351

Barium, Total μg/L 59 361

Calcium, Dissolved μg/L 21,000 80,0001

Calcium, Total μg/L 25,000 81,0001

Chromium, Dissolved μg/L 820 1.2 

Chromium, Total μg/L 720 1.3 

Cobalt, Dissolved μg/L 8.7 Not detected 

Cobalt, Total μg/L 12 Not detected 

Copper, Dissolved μg/L 370 16 

Copper, Total μg/L 820 18 

Iron, Dissolved μg/L 3,300 64 

Iron, Total μg/L 20,000 2502

Lead, Dissolved μg/L 19 1.5 

Lead, Total μg/L 64 3.0 

Magnesium, Dissolved μg/L 5,200 200,0001

Magnesium, Total μg/L 6,400 200,0001

Manganese, Dissolved μg/L 160 43 

Manganese, Total μg/L 400 551

Nickel, Dissolved μg/L 7.2 4.4 

Nickel, Total μg/L 18 4.61

Potassium, Dissolved μg/L 23,000 32,0001

Potassium, Total μg/L 23,000 32,0001

Selenium, Dissolved μg/L 45 111,4

Selenium, Total μg/L 54 112,4

Sodium, Dissolved μg/L 690,000 770,0002

Sodium, Total μg/L 630,000 860,0002

Vanadium, Dissolved μg/L 230 Not detected 

Vanadium, Total μg/L 190 Not detected 

Zinc, Dissolved μg/L 570 38 

Zinc, Total μg/L 900 38 

(1) Sample concentrations were almost completely accounted for (≥90 percent) by background concentrations in ambient water. 

(2) Sample concentrations were predominantly accounted for (≥50 percent and <90 percent) by background concentrations in 

ambient water. 

(3) Measured concentrations well above their respective reporting limits for dissolved arsenic and selenium are suspected of being 

elevated due to positive interference
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.6.6 Summary of the Characterization of Engine Effluent Analyses 

Tables 3.6.19 and 3.6.20, and Table 3.6.21 at the end of this subsection, compare effluent 

characteristics for inboard and outboard propulsion engines and generator engines. Specifically, 

Table 3.6.19 compares the number of analytes detected in effluent from these engines, while 

Table 3.6.20 compares engine effluent analyte concentrations for those pollutants that may have 

the potential to lead to environmental impacts. Finally, Table 3.6.21 summarizes the specific 

analytes within each engine effluent type with the potential to pose risk to human health or the 

environment. The Table 3.6.21 is presented here to help interpret a realized risk likely posed by 

these analytes in engine effluent as summarized in Chapter 5. 

Table 3.6.19. Comparison of Number of Detected Analytes in Engine Effluent 

Number of Analytes Detected in Engine Effluent Analyte Class Inboard Propulsion Outboard Propulsion Generator 

Classical Parameters 11 11 11 

Metals 16 14 11 

SVOCs 31 7 26 

VOCs 38 18 28 

Total 96 50 76 

Table 3.6.20. Comparison of Results for Selected Analytes in Engine Effluent 

Mean Concentration Analyte Units Inboard Propulsion Outboard Propulsion Generator 

Temperature Differential °C 5 (low power levels) 

20 (high power levels) <5 <5 to 13 

Oil and Grease (HEM) mg/L 3.0 Not detected 2.9 

Arsenic, Total μg/L 4.51 241 Not detected 

Copper, Dissolved μg/L 16 3.3 6.5 

Lead, Dissolved μg/L 1.5 Not detected Not detected 

Lead, Total μg/L 3.0 Not detected Not detected 

Selenium, Dissolved μg/L 111 761 Not detected 

Zinc, Dissolved μg/L 38 11 13 

PAHs μg/L 14 total detected 

6 carcinogens 

1 detected 

0 carcinogens 

5 detected 

0 carcinogens 

Benzene μg/L 12 13 5.9 

(1) Measured concentrations well above their respective reporting limits for dissolved arsenic and 

selenium are suspected of being elevated due to positive interference. 

Among all engine types, the SVOCs and VOCs were the most frequently detected 

pollutants (Table 3.6.19). Concentrations of PAHs were potentially high in inboard engine 

effluent. Fourteen PAHs were detected, including six of the seven PAHs classified as known 

carcinogens (Table 3.6.20), but these were only detected in a single inboard engine effluent from 

a gasoline engine of a recreational vessel (not a study vessel) dewinterized immediately prior to 

sampling. PAH concentrations in this sample were several hundred to over 1,000 times greater 

than their associated benchmarks. PAHs were also detected in outboard engine and generator 

334 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

335 

effluents, but at concentrations lower than their associated benchmarks. Furthermore, none of the 

probable human carcinogens were detected in generator or outboard propulsion engine effluent 

samples. 

The plasticizer bis(2-ethylhexyl) phthalate was found in the effluents of all engine types, 

PHQs were just above 1; however, the measured concentrations appear to be largely reflective of 

ambient concentrations. The VOC benzene was also found at concentrations above the PHQ 

screening benchmarks in all engine effluents. Trimethylbenzenes and ketones (VOCs) were 

frequently detected in the effluents of inboard engines, but no screening benchmarks exist for 

these compounds. Despite the high frequency of concentrations of benzene that exceeded 

screening benchmarks in engine effluent of all types, rarely were PHQs in excess of 5. 

Among the classical pollutants, inboard propulsion engines increase cooling water 

temperatures by moderate amounts (<5°C) at low power levels, but by as much as 20°C at higher 

power levels. In contrast, outboard propulsion engines increase cooling water temperatures by 

<5°C, regardless of engine level. Most of the generator engine effluent samples increased 

cooling water temperature by <5°C; however, two of the generator engine effluent samples had 

greater temperature differentials. 

Oil and grease was not detected in effluent from outboard propulsion engines, but was 

detected at concentrations just above reporting limits in effluent from inboard propulsion and 

generator engines. Such concentrations were well below PHQ screening benchmarks for 

saltwater discharge. However, EPA did occasionally observe a sheen in receiving waters where 

marine engines were operating. 

Table 3.6.21 lists those metals that were found to be contributed primarily by engine 

operations (elevated above ambient water concentrations) and were detected at concentrations 

that exceed a NRWQC, indicating that they may have the potential to cause environmental 

impacts. After accounting for background concentrations, dissolved concentrations of copper 

exceeded NRWQC in most inboard engine and generator effluents. The highest PHQ for 

dissolved copper was 17. Several effluents from inboard and outboard engines had dissolved 

selenium at concentrations approximately two to seven times higher than NRWQC benchmarks; 

however, these measured concententrations are suspected of being elevated due to positive 

interference. Among the total metals, PHQs for arsenic were much greater than 1 in both inboard 

and outboard engines. However, as in case of dissolved selenium, all of the arsenic values 

measured above reporting limits are suspected of being elevated due to positive interference. 

Total arsenic was not detected in generator effluents. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.6.21. Characterization of Engine Effluent and Summary of Analytes that May Have the Potential 

Analytes that May Have the Potential to Pose Risk in Engine Effluent Discharge an

Vessel Type (no. vessels)

Microbiologicals 

Volatile Organic Compounds 

Semivolatile Organic Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Sulfide 

Short-Chain Alkylphenol 

Ethoxylates or NP 

Long-Chain Alkylphenol 

Ethoxylates 

Inboard Engines 

Water Taxis (4) Benzene Bis(2-ethylhexyl) 

phthalate 

Cu 

Tour Boats(3) Benzene 

Cu 

Fishing Vessels (2) 

Cu 

 Tow/Salvage Vessel (1) 

Cu 

Fire Boat (1) Bis(2-ethylhexyl) 

phthalate Cu 

Recreational Vessel (2)4 Benzene PAHs5

Cu

x 

Outboard Engines 

Tow/Salvage Vessel (4) Benzene 

Research (2) Benzene 

336 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

337 

Table 3.6.21. Characterization of Engine Effluent and Summary of Analytes that May Have the Potential 

Analytes that May Have the Potential to Pose Risk in Engine Effluent Discharge an

Generator Engines (5) Benzene Bis(2-ethylhexyl) 

phthalate 

Cu x 

Notes: (1) Analytes are generally bolded when a large proportion of the samples have concentrations exceeding the NRWQC (e.g., 25 to 50 percent), when sev

PHQs > 10 (e.g., two or three of five), when a few samples result in PHQs greatly exceeding the screening benchmark (i.e., 100s to 1,000s), or, in the cas

nonylphenol, when one or more samples exceed an existing regulatory limit by more than a factor of 2. See text in Section 3.1.3 for a definition of PHQs a

benchmarks used to calculate these values. (2) EPA notes that the conclusion of potential risk is drawn from a small sample size, in some cases a single vessel, for certain discharges sampled from 

included these results in the tables to provide a concise summary of the data collected in the study, but strongly cautions the reader that these conclusionsamples from a given vessel class, should be considered preliminary and might not necessarily represent pollutant concentrations from these discharges class.

(3) At full (100%) power. (4) For inboard engine effluent, higher measured concentrations and concentrations that exceeded the screening benchmarks were consistently from the 

was de-winterized immediately prior to sampling (see text). The recreational vessel was the only vessel sampled that used gasoline instead of diesel fuel. 

samples were less than 5. (5) All PAHs detected (6 of which are probable human carcinogens) were from one sample collected from a recreational vessel with a gasoline engine de

to sampling and after a winter of non-use. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.7 Firemain Discharges

The primary purpose of the firemain system is to supply water for fire fighting, although 

this system can also be used for other secondary purposes (deck washing, various maintenance 

and training activities, anchor chain washdown, or to create bypass flow from the firemain 

pumps to cool auxiliary machinery equipment) onboard the vessels of interest in this study. The 

firemain systems (see Section 1.5) sampled by EPA on three tour boats, two tug boats, and the 

single fire boat for this study are generally only used during emergencies and during biweekly 

testing. The firemain system intake water sampled on the vessels selected in this study was taken 

from the surrounding (ambient) water without addition of foam-forming agents such as aqueous 

film-forming foam (AFFF) or other chemical additions. 

The Firemain Hose on a Tour Boat 

 It should be noted that AFFF agents could potentially be used on the vessels of interest 

in this study, although none of the vessels were outfitted with systems that used AFFF. AFFF 

agents are used for fire suppression and are a combination of fluoro-chemical surfactants, 

hydrocarbon surfactants, and solvents that are injected into the water stream of a fire hose. These 

film-forming agents can form water solution films on the surface of flammable liquids, 

separating the fuel from the air (oxygen). 

EPA focused on analyzing the samples of firemain discharge water for metals, VOCs, 

and SVOCs. Metals were selected for analysis because water in the “wet type” firemain system 

passes through a significant amount of metal pipe onboard most vessels. EPA initially selected 

338 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

VOCs and SVOCs to characterize the AFFF, which, as noted, none of the vessels sampled in the 

study used while testing their firemain systems. Despite the lack of AFFF use while testing 

firemain systems, EPA decided to analyze for VOCs and SVOCs in firemain system discharge 

water anyway. 

3.2.7.1 Metals 

Only half the total number of metals analyzed for in water samples from firemain systems 

were detected in the six vessels sampled. 

Figure 3.7.1 presents the concentration ranges for dissolved metals detected in firemain 

water samples. The figure shows that dissolved metals concentrations span two orders of 

magnitude. Average dissolved concentrations of aluminum and zinc were highest, followed, in 

order of decreasing concentration, by barium, copper, manganese, nickel, and lead. 

Figure 3.7.2 presents the concentration ranges of total metals detected in firemain water 

samples. Except for barium (dissolved:total metal ratio, or fd, of 0.96), total metal concentrations 

were much higher than their corresponding dissolved metal concentrations, particularly for lead 

and copper. For the other total metal concentrations detected at higher levels, a disproportionate 

amount of the metals in ambient water is in the particulate form (i.e., aluminum, manganese and 

probably iron). 

Arsenic, cadmium, selenium, antimony, beryllium, cobalt, silver, thallium, and vanadium 

were not detected in the firemain discharges. 

Dissolved and total aluminum and total manganese were detected in the firemain effluent 

of all six of the vessels sampled. These metal concentrations are moderately to strongly 

influenced by ambient water concentrations. Dissolved zinc, also moderately influenced by 

ambient water, was detected in five of the samples. Dissolved and total copper, as well as 

dissolved manganese, were detected in four of the samples and were generally not affected by 

ambient water concentrations. Total lead was detected in three of the samples, and only one of 

the firemain systems had dissolved lead and chromium at detectable levels. Dissolved and total 

barium and total iron were also detected in one sample from a firemain system. 

Disparities between dissolved:total metal concentrations sampled in firemain water 

versus ambient water suggest chromium, lead, and iron detected in firemain samples at least 

partially originated from the network of pipes within the firemain system. The dissolved:total 

metal ratio for copper was lower in the firemain water samples than in the ambient water samples 

(fds of 0.79), suggesting the possibility that some of the total copper detected in firemain samples 

originated from the network of pipes within the vessels that support the firemain system - most 

likely due to corrosion. Dissolved:total concentrations in firemain samples for the remaining 

metals (aluminum, barium, zinc, manganese, nickel) were similar to corresponding ambient 

339 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

340 

dissolved:total concentration ratios, suggesting most of these metals detected in firemain samples 

originated from the ambient water. Ambient harbor water data are not shown. 

Figures 3.7.3 and 3.7.4 display the distribution of PHQs based on the most conservative 

(most protective) screening benchmark for each of the dissolved and total metals. PHQs for only 

one of the dissolved metals (copper) include a value of greater than 10 (one dissolved copper 

concentration from the firemain system analyzed from a tour boat resulted in a PHQ of 24). 

PHQs with values of slightly higher than 1 were found for two other dissolved metals (lead and 

zinc) when using the most conservative (most stringent 2006 NRWQC) screening benchmark. In 

contrast, all of the concentrations for total aluminum and the concentrations for the single 

detected total iron value exceeded the most stringent 2006 NRWQC; however, none of these 

PHQs exceeded 11. 

In summary, the concentration of metals in firemain water was generally lower than some 

other discharges (e.g. bilgewater, deck washdown water). The water used in the vessel firemain 

systems analyzed in this study was ambient water, and the concentrations of most of the 

dissolved and total metals in firemain water reflect these surrounding ambient concentrations. 

Aluminum, manganese, and iron had high concentrations in the ambient water from which the 

firemain withdrew water and were generally higher or the same as other discharges. Dissolved 

and total copper, dissolved and total lead, and to a lesser degree, nickel and zinc, were found in 

concentrations higher than the ambient water. Of these metals, dissolved copper is the only metal 

also found at concentrations consistently above the most conservative screening benchmarks, 

albeit only with PHQ values in the 1 to 11 range, which is considerably lower than values found 

in most other discharge types discussed in this report. 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.7.1. Results of Firemain System Sample Analyses for Metals1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. 5 Median Conc. Minimum Conc. 10% 25% 75% 90% 

Heavy and Other Metals 

Aluminum, Dissolved3 μg/L 6 6 100 110 140 15 15 72 150 160 Aluminum, Total4 μg/L 6 6 100 330 360 180 180 200 440 650 Barium, Dissolved3 μg/L 1 1 100 36 Barium, Total3 μg/L 1 1 100 37 Chromium, Total4 μg/L 6 1 17 1.7 1.2 4.9 Copper, Dissolved μg/L 6 4 67 23 15 40 74 Copper, Total μg/L 6 4 67 150 70 290 580 Iron, Total μg/L 1 1 100 3800 Lead, Dissolved μg/L 6 1 17 2.1 1.1 4.3 Lead, Total μg/L 6 3 50 50 7.6 81 270 Manganese, Dissolved4 μg/L 6 4 67 17 16 31 47 Manganese, Total4 μg/L 6 6 100 86 98 49 49 59 120 120 Nickel, Dissolved4 μg/L 6 1 17 4.9 1.1 4.4 Nickel, Total4 μg/L 6 2 033 7.0 11 11 Zinc, Dissolved4 μg/L 6 5 83 120 58 5.3 270 370 Zinc, Total μg/L 6 6 100 490 280 20 20 26 1200 1600 

Cationic Metals 

Calcium, Dissolved3 μg/L 6 6 100 27000 25000 23000 23000 24000 29000 37000 Calcium, Total3 μg/L 6 6 100 30000 29000 23000 23000 23000 38000 40000 Magnesium, Dissolved3 μg/L 6 6 100 6500 6500 5200 5200 5700 7200 9000 Magnesium, Total3 μg/L 6 6 100 7300 6600 5500 5500 6200 9200 9800 Sodium, Dissolved3 μg/L 1 1 100 38000 Sodium,Total3 μg/L 1 1 100 37000 Potassium, Dissolved3 μg/L 1 1 100 3800 Potassium, Total3 μg/L 1 1 100 3600 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this table were only calcu

detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentration was not calculated. A blank cell reflects 

percentile could not be computed based on detected concentrations. The percentiles are the concentrations of each analyte below which at least that percentage of the values 

concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchmark used to calculate 

(3) Sample concentrations were strongly influenced by background concentrations in ambient water, accounting for greater than 90% of sample concentrations in the majority o

(4) Sample concentrations were moderately influenced by background concentrations in ambient water, accounting for between 50 and 90% of sample concentrations in the m(5) In some cases, the detected concentration(s) for an analyte could be lower than the replacement value (1⁄2 of the reporting limit) for a concentration that was nondetected. In 

this could result in an average concentration for an analyte that is greater than the maximum detected concentration. 

341 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

342 

Figure 3.7.1. Box and Dot Density Plot of Dissolved Metals Concentrations Measured in 

Samples of Firemain Water 

Aluminum

Barium

Copper

Lead

Manganese

Nickel

Zinc

Dissolved Metals

1

10

100

C

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

343 

Figure 3.7.2. Box and Dot Density Plot of Total Metals Concentrations Measured in 

Samples of Firemain Water 

Aluminum

Barium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Total Metals

1

10

100

1000

C

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

344 

Figure 3.7.3. Box and Dot Density Plot of Potential Hazard Quotients for Dissolved Metals 

in Samples of Firemain Water

(Note: Replacement values for non-detects are circled). 

Aluminum

Barium

Copper

Lead

Manganese

Nickel

Zinc

Dissolved Metals

0.1

1.0

10.0

P

ote

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a

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a

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

345 

Figure 3.7.4. Box and Dot Density Plot of Potential Hazard Quotients for Total Metals in 

Samples of Firemain Water 

(Note: Replacement values for non-detects are circled). 

10.000

Aluminum

Barium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Total Metals

0.001

0.010

0.100

P

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a

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.7.2 Classical pollutants 

The firemain system water samples were analyzed for 10 classical pollutants (BOD, 

COD, TOC, and sulfide were not analyzed for as they were not expected in firemain system 

discharge (see Table 2.2). Of the 10 classical pollutants analyzed for, oil and grease (measured as 

HEM and SGT-HEM) were not detected in any samples (Table 3.7.2). The concentrations of all 

other pollutants, with the possible exception of turbidity, were not elevated. 

The conductivity, pH, and low salinity (ranging from 0.01 to 0.2 parts per thousand) in 

the firemain water samples are consistent with freshwater ambient water (all firemain samples 

were taken from vessels operating in fresh water). The pH of these waters was between 7 and 8, 

and turbidity and TSS was low, under 90 NTU and 20 mg/L, respectively. The firemain system 

effluent was sampled in the spring, and the temperature was in a seasonal range of 14 to 22o

C 

and varied according to geographic location (warmer water samples in southern United States 

and colder in mid-Atlantic and northern states). Dissolved oxygen in firemain system water 

ranged from a low of 4.1 mg/L (slightly less then 50 percent saturation) to a high of 13 mg/L 

(super-saturated). All of these values were, to a large degree, consistent with concentrations of 

these parameters found in respective ambient water. 

Figure 3.7.5 illustrates the variability of the values measured for the classical pollutants 

in firemain system water, which is relatively low given the relative similarities in ambient water 

quality (freshwater harbors sampled during springtime) for the three locations where vessels 

were sampled. The only other parameters detected in this category were TRC and turbidity. TRC 

was only detected in one of the six samples collected (measured at the reporting limit = 0.10 

mg/L; PHQ = 13). All of the other TRC concentrations were below the reporting limit of 0.10 

mg/L, which, when reported at half the reporting limit or 0.05 mg/L, still exceeds the most 

stringent 2006 NRWQC for TRC of 0.0075 mg/L. In contrast, turbidity ranged from a low of 4.6 

to a high of 89 NTU, concentrations similar to the range of turbities (3 to 180 NTU) observed in 

estuaries. In contrast, turbidity in raw sewage can be several hundred NTUs or more. There is no 

screening benchmark for turbidity from which to assess potential to cause or contribute to 

adverse effects on water quality. 

To summarize, the concentrations of classical pollutants in firemain system water 

samples are within the normally expected ranges for the given season and geographical location 

where vessels were sampled. It appears that the classical pollutant concentrations primarily 

reflect concentrations found in the ambient water. 

346 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.7.2. Results of Firemain System Water Sample Analyses for Classical Pollutants1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc. Median Conc. Minimum Conc. 10% 25% 7

Conductivity mS/cm 5 5 100 0.32 0.24 0.23 0.23 0.24 0Dissolved Oxygen mg/L 5 5 100 7.7 6.8 4.1 4.1 4.9 pH SU 6 6 100 7.4 7.4 6.9 6.9 7.0 Salinity ppt 5 5 100 0.12 0.10 0.010 0.010 0.055 0Temperature C 5 5 100 18 19 14 14 15 Total Residual Chlorine mg/L 6 1 17 0.05 0Total Suspended Solids (TSS) mg/L 1 1 100 16 Turbidity NTU 6 6 100 33 27 4.6 4.6 16 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

347 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

348 

Figure 3.7.5. Box and Dot Density Plot of Classical Pollutants Measured in Samples of 

Firemain Water 

(Note: Concentrations reflect ambient water concentrations and values because ambient water was used as the 

source of water for all fireman systems in the vessels sampled in the study program). 

Cond (mS/cm)

DO (mg/l)

Salin. (ppt)

TRC (mg/l)

TSS (mg/l)

Temp. (C)

Turb. (NTU)

pH (SU)

Classical Pollutants

0.01

0.10

1.00

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.7.3 Volatile and Semivolatile Organic Chemicals 

VOC and SVOCs were targeted in firemain systems for this program because of the 

expectation that AFFF agents might be injected into the water stream of a fire hose to practice 

potential fire suppression scenarios. AFFF was not used, however, by any of the vessels sampled 

for this study. 

Of the 57 SVOCs that were analyzed for in the six firemain system water samples, only 

six were detected, none of which were detected in more than one sample (Table 3.7.3 and Figure 

3.7.6). Similarly, of 37 VOCs analyzed for, only five were detected, and as with the SVOCs, 

none were detected in more than one sample (Table 3.7.3). When SVOC and VOC 

concentrations were above detection levels, concentrations were relatively low. Of these, only 

bis(2-ethylhexyl) phthalate was measured at a sufficiently high concentration of 4.6 μg/L that 

exceeded the associated PHQ of 3.8, based on the most conservative screening benchmark of 1.2 

μg/L (human health criterion). Bis(2-ethylhexyl) phthalate was also the only SVOC or VOC 

detected in ambient water, but interestingly, at a slightly higher concentration of 13 μg/L. 

349 
Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.7.3. Results of Firemain Water Sample Analyses for SVOCs 1

Analyte Units No. samples No. detected Detected Proportion (%) Average Conc.1 Median Conc. Minimum Conc. 10% 25% 75% 90% 

SVOCs 

2,6,10,14-Tetramethyl Pentadecane μg/L 1 1 100 9.9 2-Mercaptobenzothiazole μg/L 1 1 100 4.1 Benzothiazole μg/L 1 1 100 7.2 Bicyclo[2.2.1]heptane,1,7,7-Trimethyl- μg/L 1 1 100 14 Bis(2-ethylhexyl) phthalate μg/L 4 1 25 2.1 3.4 4.6 Isopropylbenzene-4,methyl-1 μg/L 1 1 100 9.9 

VOCs 

1-Methyl-2-(1-Methylethyl)-Benzene μg/L 1 1 100 97 1-Methyl-4-(1-Methylidene)-Cyclohexane μg/L 1 1 100 6.8 Limonene μg/L 1 1 100 9.5 n-Pentadecane μg/L 1 1 100 3.8 n-Tetradecane μg/L 1 1 100 3.5 

Notes: (1) Nondetect (censored) concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations. The remaining statistics in this 

when analytes were detected at a sufficient frequency. For example, if an analyte was detected in fewer than 50% of samples, then a median concentrati

cell reflects a situation when a median or percentile could not be computed based on detected concentrations. The percentiles are the concentrations of eleast that percentage of the values fall. So the 10th percentile is the concentration below which at least 10% of the observations were found. (2) Screening BM represents the screening benchmark referred to in Section 3.1.3, and is the most stringent 2006 NRWQC or other conservative benchm

350 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

351 

Figure 3.7.6. Box and Dot Density Plot of SVOC Concentrations Measured in Samples of 

Firemain Water 

SVOCs are identified as follows: 

(1) 2,6,10,14-Tetramethyl 

Pentadecane, 

(2) 2-Mercaptobenzothiazole, 

(3) Benzothiazole, 

(4) Bicyclo[2.2.1]Heptane,1,7,7-

Trimethyl-, 

(5) Bis(2-Ethylhexyl) Phthalate, 

(6) Isopropylbenzene-4, Methyl1 

0 1 2 3 4 5 6 7

SVOCs

2

4

6

8

10

12

14

16

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.7.4 Summary of the Characterization of Firemain System Water Analyses 

Table 3.7.4 summarizes the specific analytes in firemain system effluent that may have 

the potential to pose risk to human health or the environment. EPA’s interpretation of a realized 

risk likely posed by these analytes, relative to pollutant loadings, background ambient and source 

water contaminant levels and characteristics, and other relevant information useful for this 

assessment, is presented in Chapter 5. 

The proportion of dissolved to total metals for firemain system discharge was low 

overall, relative to other discharge types. Among the dissolved metals, copper was detected in 

the highest concentrations and exceeded the NRWQC in the largest number of samples (four of 

six samples). The corresponding PHQs for dissolved copper ranged from approximately 4 to 

over 20. Dissolved lead and zinc had concentrations that exceeded the most conservative 

NRWQC in one and three samples, respectively, but none of the PHQs were above 10. Total 

aluminum and iron concentrations exceeded NRWQC benchmarks in all samples, with PHQs 

ranging from 1-5 (aluminum) and of approximatley 13 (iron; single sample from a fire boat). 

However, most of the aluminum in firemain discharge can be attributed to aluminum in the 

ambient waters. Overall, the concentrations of metals in firemain discharge were low compared 

to other discharge types. 

Among the classical pollutants, TRC was the only pollutant of potential concern. 

However, TRC was detected right at the reporting limit of 0.10 mg/L in only one of six samples 

and the concentration likely reflects an elevated TRC concentration in the ambient water. 

Finally, the concentration of bis(2-ethylhexyl) phthalate (an SVOC) exceeded the 

NRWQC (PHQ = 3.8) in one discharge sample; however, most SVOCs and VOCs sampled for 

were below detection limits, and when they were detected, occurred at very low concentrations. 

It is noteworthy to reiterate that bis(2-ethylhexyl) phthalate was also the only SVOC or VOC 

detected in ambient water, and at a slightly higher concentration (13 μg/L) than in the one 

firemain water sample. 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human 

Table 3.7.4. Characterization of Firemain Discharge and Summary of Analytes that May Have the Potenti

Analytes that May Have the Potential to Pose Risk in Firemain Discharge and Probable Source1, 2

Vessel Type (no. vessels)

Microbiologicals 

Volatile Organic Compounds 

Semivolatile Organic Compounds 

Metals (total and dissolved) 

Oil and Grease 

Sulfide 

Short-Chain Alkylphenol 

Ethoxylates and NP 

Long-Chain Alkylphenol 

Ethoxylates 

Nutrients 

BOD, COD, and TOC 

Total Suspended Solids 

Tour (3) Bis(2-ethylhexyl) 

phthalate 

Cu(dissolved); 

Fe (total) 

Tug (2) 

Fireboat (1) Cu (dissolved) 

Notes: (1) EPA notes that the conclusion of potential risk is drawn from a small sample size, in some cases a single vessel, for certain discharges sampled from included these results in the tables to provide a concise summary of the data collected in the study, but strongly cautions the reader that these conclusionsamples from a given vessel class, should be considered preliminary and might not necessarily represent pollutant concentrations from these discharges class. (2) Analytes are generally bolded when a large proportion of the samples have concentrations exceeding the NRWQC (e.g., 25 to 50 percent), when sevePHQs > 10 (e.g., two or three of five), when a few samples result in PHQs greatly exceeding the screening benchmark (i.e., 100s to 1,000s), or, in the cas

nonylphenol, when one or more samples exceed an existing regulatory limit by more than a factor of 2. See text in Section 3.1.3 for a definition of PHQs a

benchmarks used to calculate these values. 

353 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.8 Antifouling Hull Coatings 

Antifouling hull systems (AFSs) are specialized paints and other coatings intended to 

retard the growth of algae, weeds, and encrusting organisms such as barnacles and zebra mussels 

on the underwater portion of vessel hulls. These organisms may foul hulls and other underwater 

parts, increasing corrosion and drag, reducing safety and maneuverability, decreasing fuel 

efficiency and economy, and lengthening transit times (WHOI, 1952). Vessel hull fouling is 

often significant as vessels can move between a diverse range of aquatic environments and 

remain in the photic zone that is the most productive region of the water body (Chambers et al., 

2006). Exposed to a variety of organisms, vessel hulls can transfer the organisms into other water 

bodies, where they can become invasive species38. 

. 

Figure 3.8.1. Encrusting organisms (left) and weeds (right) growing on vessel hulls 

(figures from the Naval Surface Warfare Center’s Carderock Division, West 

Bethesda, Maryland, and the Boating Industry 

Association of Victoria, South Melbourne, 

Australia39). 

The development of AFSs has a long history, as 

mariners have tried for centuries to keep vessel bottoms free 

of barnacles and other fouling growth (Yebra et al., 2004; 

Readman, 2006). Ancient civilizations of the Greeks and the 

Romans coated their vessels with lead sheathing secured by 

What is a Biocide? 

A biocide is a chemical 

substance capable of 

killing living organisms, 

usually in a selective 

way. 

 

38 For this report, EPA did not evaluate the relationship between Anti Foulant Systems, fouled vessel hulls and the 

transport/spread of invasive species Other studies have shown that fouled vessel hulls contribute to the spread of 

invasive species and increase fuel consumption, thereby increasing greenhouse gas emissions and vessel operator 

cost. Though it is beyond the scope of this study, preventing vessel hull fouling provides important environmental 

and economic benefits, however, as discussed in this section, biocidal anti-foulant paints can also contribute to 

environmental degradation. 

39 See http://www.dt.navy.mil/sur-str-mat/fun-mat/pai-pro-bra/fou-con-tec/images/fouling.jpg and 

http://www.biavic.com.au/files/weedunderhull.jpg, respectively, for access to figures. 

354 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

copper nails. These heavy metals were early examples of using biocides to control fouling. 

Columbus’ ships are thought to have been coated with pitch and tallow. In the United Kingdom, 

lead sheathing was abandoned by the Navy in the late 1600s, and antifouling paints containing 

tar, grease, sulphur pitch and brimstone were developed (Carberry, 2006). One hundred years 

later, copper sheathing was used that prevented fouling through dissolution of the toxic metal 

ions (Readman, 2006). With the introduction of iron ships in the mid-1800s, different antifouling 

paints were needed because the copper sheathing reacted with the hull material to hasten 

corrosion of the iron. New paints were developed by adding toxic biocides such as copper oxide, 

arsenic, and mercury oxide to resin binders. Following the Second World War, the introduction 

of petroleum-based resins and health and safety concerns relating to arsenic- and mercurycontaining paints meant that copper-based paints became most popular (Readman, 2006). 

In the late 1950s and early 1960s, new antifouling paint formulations using tributyltin 

(TBT) proved to be excellent in preventing hull fouling. TBT, especially in “self-polishing” 

formulations, proved very efficient, and the application of TBT-based paints rapidly expanded. 

TBT was frequently formulated together with cuprous oxide to control a broader range of 

organisms. Not only was antifouling performance improved, but tin-based formulas (without 

copper components) are noncorrosive to aluminum, which was being used more in the 

construction of vessel hulls and propulsion systems. Unfortunately, the use of TBT also had 

severe and unexpected environmental consequences (Carberry, 2006). As the popularity of TBT 

grew, oyster producers in France reported shell malformations caused by paint leachate 

containing TBT that rendered their harvest worthless. Wild populations of other mollusc species 

were also affected at very low concentrations of TBT in the water and sediment (Evans et al., 

1994). For example, female dog whelks (Nucella sp.) developed male characteristics (termed 

imposex) at these levels (Bryan et al., 1986). This masculinization of female gastropods was also 

reported in the open North Sea (Ten Hallers-Tjabbes et al., 1994). TBT use on small vessels was 

phased out in the late 1980s, when EPA and other regulatory agencies (including those in 

Canada, Australia, and many in Europe) restricted use of TBT-based AFSs to ships longer than 

25 meters (see Section 6.2.3 of this report for further discussion about regulatory elimination of 

TBT).

Restrictions on the use of TBT-based AFSs opened the market for paint manufacturers 

and chemical companies developing new biocides for new antifouling paints to be used on 

vessels. Other metallic species, such as copper (copper hydroxide, copper thiocyanate) and zinc 

(zinc pyrithione), are currently used as substitutes for TBT. Copper oxide (in formulations 

without TBT) is by far the most common of the metallic biocides, used in more than 90 percent 

of the approximately 180 AFS products registered in California (Singhasemanon, 2008). A single 

AFS product might actually contain multiple biocides, with “booster biocides” incorporated to 

increase the duration and functionality of copper-based AFSs (Chambers et al., 2006). Irgarol is 

currently the organic biocide booster most frequently formulated into AFS products. As was the 

case for TBT, the biocides used in AFSs today can be toxic to a range of aquatic organisms, not 

355 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

just fouling organisms. In the subsections below, EPA discusses the literature on studies of 

adverse effects of these AFS biocides to aquatic resources as well as alternatives to using 

biocidal AFSs. 

EPA did not sample antifouling systems as part of this study because of lack of time and 

resources available for this study. Assessing AFS discharge involves isolating a commercial 

vessel within a confined body of water (a “boat bag” or slip liner), and measuring the release, 

discharge, or leaching of the AFS biocide(s) over a period of time (weeks or months); the 

amount of time needed for the study would impose economic hardship on the vessel’s owners 

and operators. Rather, EPA elected to rely on the significant secondary data on anitifouling 

systems available in the literature. 

3.2.8.1 Copper Biocides 

Copper is typically the biocide added to antifouling paints to prevent biofouling 

organisms from attaching to the hull. The most common form of copper used in AFSs is cuprous 

oxide, which acts as a preventative biocide by leaching into the water body. Cuprous oxide 

concentrations in marine antifouling paints range from 26 to 76 percent by weight, with most 

paints in the 40- to 70-percent range. Since cuprous oxide is 89 percent copper by weight, typical 

cuprous oxide marine antifouling paints are 36 to 62 percent copper by weight (TDC 

Environmental, 2004). Two additional copper biocides are occasionally used in AFSs: copper 

thiocyanate and copper hydroxide. These formulations are not as common, although copper 

thiocyanate has the advantage of being compatible with aluminum. The contribution of copper 

from these paints to receiving water is small relative to AFSs containing cuprous oxide (TDC 

Environmental, 2004). 

Conventional copper-based AFSs fall into several general categories: copolymer or 

ablative paints and hard contact leaching paints (Conway and Locke, 1994). Copolymer paints 

release biocide at a constant rate, ablating (wearing away) much like a bar of soap, which is 

intended to reduce the need for cleaning. Hard contact leaching paints are usually modified 

epoxy paints that leach biocide upon contact with water, and, over time, the biocide is released at 

a decreasing rate. Each of these coating formulations can benefit from periodic hull cleaning to 

remove fouling growth, maintain a smooth surface, and improve the copper release on vessel 

hulls, but underwater hull cleaning can be a source of pollution or introduce non-native species if 

not done carefully. Cleaning frequencies and methods vary by paint type, area of vessel 

operation, frequency and conditions of operation, and vessel operator’s needs. Techniques that 

capture removed fouling growth and paint residue reduce negative impacts on the environment. 

Passive leaching rates from antifouling paint, including those that are copper-based, 

depend on a number of factors, including the paint matrix (e.g., vinyl, epoxy), copper content, 

age of the paint, time since last hull cleaning, and frequency of painting. Leaching rates also vary 

356 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

with environmental conditions such as pH, temperature, salinity, and the existing slime “biofilm” 

layer (CRWQCB, 2005). 

Rates of passive leaching of dissolved copper from AFSs on seven recreational vessels 

painted with epoxy copper antifouling paints were investigated in studies conducted in Southern 

California by the U.S. Navy, under test conditions intended to represent realistic vessel 

conditions. Copper release rates were found to range from 2 to 14 μg/cm2

/day, with an average 

leaching rate of 8.2 μg/cm2

/day40. In another study of copper-based AFSs on recreational 

vessels, researchers with the Southern California Coastal Water Research Project (SCCWRP) 

measured the mass emissions of dissolved copper from both passive leaching and underwater 

hull cleaning (Schiff et al., 2003). Fiberglass panels were painted with copper-based antifoulin

paints and immersed in seawater in a harbor environment. SCCWRP researchers determined th

average flux rates for epoxy and hard vinyl copper antifouling paints to be approximately 4.3 

3.7 μg/cm2

/day over the course of a month, respectively. In the SCCWRP study, the authors al

discussed the comparability of the results between the U.S. Navy and SCCWRP studies. 

According to the authors, the range of passive leaching measurements from the U.S. Navy study 

was within the range of measurements obtained in the SCCWRP study. By combining the results 

from the two studies, an average passive leaching rate for vessels at the Shelter Island Yacht 

Club (SIYB) was determined to be 6.5 μg/cm2/day (CRWQCB, 2005). In the United Kingdom, 

Thomas et al. (1999) found higher copper leaching rates for ablative copper antifouling paint 

ranging from 18.6 to 21.6 μg/cm2

/day in 17 day experiments (Schiff et al., 2003). Table 3.8.1 

summarizes the passive leaching rates for vessel AFSs found in the literature. The copper 

leaching rates summarized in this table were measured in experiments designed to simulate 

environmentally relevant conditions. However, more recently developed types of AFSs may 

leach at different rates, and the actual rates of copper leaching from many vessels and real-world 

environmental conditions may differ from those in Table 3.8.1

g 

e 

and 

so 

 

41. 

Estimates of copper released from AFS leaching and underwater hull cleaning were 

calculated based upon the 6.5 μg/cm2

/day average flux rate cited above, which was extrapolated 

to vessels using the underwater surface area of the hull42, and then to marinas (or harbors) based 

on the number of vessels in the marinas. Despite the caveats and limitations discussed above, 

EPA uses these estimates in Chapter 4 to calculate loadings from vessel hull AFSs to attempt to 

40 EPA notes that a calculated average for release rates will not reflect real-world conditions for many vessels and 

environmental conditions. 

41 Additional test data for copper AFC leaching rates were provided to EPA by the Antifouling Coatings Work 

Group (AFWG) of the American Coatings Assoc iation (ACA) during the public comment period. These data 

substantially agree with EPA's best estimate of copper AFC leaching rate (6.5 μg/cm2

/day) used for water quality 

modeling in Chapter 4.

42 Hull surface area can be estimated using the following equation: Hull Surface Area = VesselLength*Beam*0.85 

(Interlux, 1999). 

357 
Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

understand the impacts of this source of copper discharge from certain vessels on large water 

bodies. 

Even when an effective AFS is used, the biofouling could accumulate over time to 

unacceptable levels. If the AFS is still viable, this accumulated growth can be removed from 

vessel hulls by a number of methods, most frequently by underwater hull cleaning. Several 

studies have investigated the release of copper from copper-based AFSs into water bodies during 

underwater hull cleaning. The amount of copper released depends on cleaning frequency, method 

of cleaning, type of paint, and frequency of painting (SWRCB, 1996). Valkirs et al. (1994) found 

that underwater hull cleaning resulted in elevated total copper concentrations near the vicinity of 

the operation as dissolved copper was released during and shortly after hull cleaning. Smaller 

amounts of dissolved copper also leached from debris and sediments after cleaning. The 

particulate form of copper was rapidly incorporated into the bottom sediment, likely rendering it 

unavailable to aquatic organisms. The biologically active species of copper complexed rapidly, 

and dissolved copper levels returned to precleaning conditions within minutes to hours after the 

hull cleaning. Valkirs et al. (1994) concluded that potential adverse effects of hull cleaning on 

aquatic organisms from the increased dissolved copper concentrations were relatively short-term 

and pulsed in nature, while the potential adverse effects of increased particulate copper were 

probably long-term in nature, and dependent on resuspension or sediment uptake from benthic 

organisms. 

McPherson and Peters (1995) also studied the effects of underwater hull cleaning on 

water body copper concentrations and toxicity to aquatic life. In the study, an underwater hull 

cleaning operation was performed in Shelter Island Yacht Basin using Best Management 

Practices (BMPs) that used less abrasive techniques to remove fouling growth (e.g., hand-wiping 

with a soft cloth). Most of the copper released during the cleaning was in the dissolved form. 

Researchers found that the plume of copper released by cleaning moved with the current, and 

that the degree of plume contamination depended on fouling extent and exertion by the diver. 

McPherson and Peters (1995) concluded that underwater hull cleaning elevates concentrations in 

the vicinity of the operation, which return to background levels within minutes. The researchers 

did not identify the type of antifouling paint (ablative or contact leaching paint), the age of the 

antifouling paint on the vessel, or the time since last hull cleaning. While the study provided 

important information regarding impacts of underwater hull cleaning on water quality, it did not 

provide copper emission rates associated with hull cleaning. 

Schiff et al. also estimated dissolved copper emissions rates associated with underwater 

hull cleaning. Fiberglass panels were painted with copper antifoulants to simulate the hulls of 

recreational vessels. The study objective was to estimate the flux rates of dissolved copper from 

underwater hull cleaning of vessels painted with two commonly used types of copper-based 

antifouling paints in San Diego Bay. Schiff found that hull cleaning released between 3.8 to 17.4 

μg/cm2

 per event (see Table 3.8.2), with an average release of 8.6 μg/cm2/event. The researchers 

concluded that underwater hull cleaning results in a greater daily load of copper to the 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

environment than passive leaching. In terms of mass loading, the authors concluded that 

approximately 95 percent of dissolved copper from antifouling paint enters the environment via 

passive leaching (CRWQCB, 2005). EPA notes, however, that this does not include loading rates 

from particulate copper, which may also impair the environment in the benthos due to 

biogeochemical cycling. 

AFSs that are applied to vessel hulls are one of the most commonly identified major 

sources for copper in marinas. A number of studies have been carried out to estimate the loading 

of copper from vessel AFSs. EPA estimated that copper loading from AFS use in California’s 

Lower Newport Bay (LNB) area, which harbors approximately 10,000 boats, contributed more 

than 62,000 pounds of copper (via passive leaching and underwater hull cleaning) into LNB 

waters annually (USEPA, 2002). EPA believed that this load could account for as much as 80 

percent of all copper input into LNB. 

The U.S. Navy and private researchers conducted two copper source loading studies for 

the San Diego Bay in the late 1990s (Johnson et al., 1998; PRC, 1997). Both studies concluded 

that AFSs accounted for the majority of dissolved copper loading to the bay. The San Diego 

Regional Water Quality Control Board (SDRWQCB) estimated that passive leaching and 

underwater hull cleaning of the 2,400 boats berthed in the SIYB marina combine to contribute 98 

percent of the copper load to the basin (Singhasemanon et al., 2009). Of the approximately 1.8 

pounds of copper estimated released per boat per year (TDC Environmental, 2004), about 95 

percent is believed to leach from AFS while boats are moored at the dock; the remaining 5 

percent is believed to be released during monthly underwater hull cleaning activities. 

The constant input of copper by leaching from the AFSs applied to pleasure, commercial, 

and military vessels has been cited as a likely primary source of copper in San Diego Bay. 

Sediment concentrations measured at the SIYB were relatively high (from 133 to 212 mg/kg) 

compared to other areas in San Diego Bay (Valkirs et al., 1994). Elevated copper concentrations 

(108 to 270 mg/kg) were found throughout San Diego Bay, with small boat harbors, commercial 

shipping berths, and military berths most affected. This distribution pattern is expected, 

considering the historical use of copper-based antifouling paints in the area. 

Marinas in general tend to have elevated levels of pollutants in the water and sediments, 

including copper, as explained later in this subsection. For example, monitoring in the Southern 

California Bight demonstrated that sediment from marinas throughout southern California had 

consistently elevated copper levels compared to surrounding waters (Bay et al., 2000). The 

National Oceanic and Atmospheric Administration (NOAA , 1991) found the highest sediment 

concentrations, reaching over 104 mg copper/dry kg, in marinas, compared to other areas 

throughout the Southern California Bight. Sediment quality surveys around the United States 

routinely find high copper concentrations in marinas and harbors (USEPA, 1996; NOAA, 1994). 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

A recent study of AFS biocides in California marinas found dissolved copper 

concentrations ranging from 0.1–18.4 μg/L (Singhasemanon, 2008) in the water. Concentrations 

were significantly higher in salt- and brackish water marinas than in freshwater marinas. 

Dissolved copper concentrations in many of the salt- and brackish water marinas exceeded 

established water quality standards. Thus, there are ecological risks due to copper in many salt 

and brackish water marinas (Singhasemanon, 2008). 

Copper contamination from vessel hulls is a water quality problem that is not unique to 

California. Within the United States, other areas of current concern to regulators include 

Chesapeake Bay, Maryland; Port Canaveral and Indian River Lagoon, Florida; and various 

harbors in the state of Washington (Carson et al, 2009). 

Elevated copper levels in marinas may be attributable to a number of factors. Marinas are 

home to high concentrations of recreational and commercial vessels. Since recreational vessels 

spend much of their time moored in marinas, most of the biocide from the antifouling paints on 

the vessel hulls is released in the marinas. Moreover, marinas are purposefully constructed to 

shelter boats from currents and waves, so they are not flushed well. Elevated trace metal 

concentrations in marinas are partly the result of the lack of mixing and dispersion. Thus, AFS 

pollution at these locations would represent some of the worst-case scenarios with regard to 

water quality (Singhasemanon et al., 2009; CRWQCB, 2005). 

 The biocides leached from AFSs can accumulate in the water of poorly flushed boat 

basins to levels that might harm marine life, especially mollusks, crustaceans, and echinoderms 

(Johnson and Gonzalez, 2006). At relatively low concentrations, copper is toxic to a wide range 

of aquatic organisms, not just fouling organisms (CRWQCB, 2005). Concentrations as low as 5 

to 25 μg/L can be lethal for marine invertebrates (Chambers et al., 2006). Elevated copper levels 

affect growth, development, feeding, reproduction, and survival at various life stages of fish, 

mussels, oysters, scallops, crustaceans, and sea urchins. High copper levels also change the types 

of phytoplankton that thrive in boat basins (Calabrese et al., 1984). Low levels of dissolved 

copper affect the olfactory capabilities in juvenile Coho salmon, which is critical for homing, 

foraging, and predator avoidance (Baldwin et al., 2004). The effect of copper on olfaction of 

juvenile salmonids suggests that copper might affect other fish species, too. Most effects on fish 

are sublethal (e.g., they may hinder metabolic processes, reproduction, development, activity 

levels and behavior). Thus, the damage is chronic and less noticeable than, for example, fish kills 

caused by sudden oxygen depletion (Evans et al., 1994). 

In the California marina study, significant toxicity was measured in eight of 47 water 

samples; seven of the toxic samples came from Marina del Rey (MdR) in Los Angeles 

(Singhasemanon et al., 2009). The authors concluded that copper was the most likely cause of 

the toxicity in these samples. Two models of copper bioavailability and toxicity to aquatic 

organisms, the Biotic Ligand Model (BLM) and dissolved organic carbon (DOC) model, were 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

used to confirm these findings. The BLM and DOC model predictions agreed favorably with the 

actual toxicity data, although both models tended to slightly overpredict toxicity, especially when 

close to the toxic effect concentration (i.e., EC50) (Singhasemanon, 2008). 

Rivera-Duarte et al. (2003) also investigated the bioavailability and toxicity of copper in 

San Diego Bay and found that toxicity was based on chemical speciation and followed the free 

ion activity model. The EC50 for mussel larval development was observed near 10-11 molar (i.e., 

0.64 ng/L) free copper ion. The toxic threshold concentration of free copper ion was independent 

of spatial and temporal effects, indicating the need to study chemical speciation of copper 

released from antifouling paints in order to determine its environmental effects (Rivera-Duarte et 

al., 2003). 

Table 3.8.1. Rates of Passive Copper Leaching from Vessel AFSs 

Study Test Method AFS Leaching Rate 

(μg/cm2/day) 

UK (Thomas et al., 1999) Not reported Ablative copper 

antifouling paint 18.6 – 21.6 

U.S. Navy (Zirino and 

Seligman, 2002) Not reported Ablative copper antifouling paint Average = 3.9 

U.S. Navy (Valkirs et al., 

2003) 

7 recreational 

vessels in 

recirculating dome 

system 

Epoxy copper 

antifouling paint 

2 - 14 

(average = 8.2) 

Epoxy copper 

antifouling paint 4.3 

Hard vinyl/Teflon copper 

antifouling paint 3.7 SCCWRP (Schiff et al., 

2003) 

Fiberglass panels 

in recirculating 

dome system 

Biocide-free coating 0.24 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

Table 3.8.2. Dissolved Copper Release from Vessel AFSs During an Underwater 

Hull Cleaning “Event”

AFS Cleaning Method Copper Release 

(μg/cm2/event) 

Less abrasive management 

practices 8.6 Epoxy copper antifouling paint 

No management practices 17.4 

Less abrasive management 

practices Hard vinyl/Teflon copper 3.8 

antifouling paint No management practices 4.2 

Less abrasive management 

practices 0.03 

Biocide-free coating 

No management practices 0.05 

Source: Schiff et al., 2003

Table 3.8.3. Estimated Dissolved Copper Mass Emissions from a 9.1m (30ft) 

Powerboat 

Dissolved Copper Emission (grams/month) 

Source 

Epoxy Copper Antifouling Paint Hard Vinyl/Teflon Copper 

Antifouling Paint

Biocide-Free 

Coating

Passive leaching 

(min-max) 

24.9 

(23.3-27.8) 

21.4 

(15.7-24.5) 

1.4 

(0.9-1.8) 

Underwater hull 

cleaning with BMPs 

(min-max) 

1.8 

(1.7-2.0) 

0.8 

(0.5-1.2) 

<0.01 

(0-0.01) 

Total emissions 

(min-max) 

26.7 

(20.5-33.6) 

22.2 

(15.0-31.5) 

1.4 

(0.9-1.8) 

Source: Schiff et al., 2003 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

3.2.8.2 Irgarol and Other Organic Biocide Boosters 

Irgarol (Irgarol 1051, N-tert-butyl-N′-cyclopropyl-6-methylthio- 1,3,5-triazine-2,4-

diamine) is a highly effective biocide used in AFSs to prevent the growth of autotrophic (e.g., 

plants and algae) organisms on vessel hulls. After the ban of tributyltin (TBT) on vessels shorter 

than 25 meters, the use of TBT-free paints containing copper compounds and organic booster 

biocides such as Irgarol increased considerably and became more widespread (Mohr et al., 

2009). Other organic biocides, including Diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea), 

dichlorofluanid (1,1-dichloro-N-(dimethylamino)sulfonyl)-1-fluoro-Nphenylmethanesulfenamide), and Sea-Nine (4,5-dichloro-2-n-octyl-4-isothiazolino-3-one) are 

also added to AFS preparations to boost performance (Thomas et al., 2001). The use of biocide 

boosters is in part a response to concerns about performance, environmental impacts, and, 

according to Chambers et al., (2006), a reported increasing tolerance of some macrophytes and 

algae to copper. Freshwater locations such as the Great Lakes are plagued primarily by algae 

(West Marine, 2008), and booster biocides such as Irgarol are used to restrict the growth of algae 

by blocking photosynthesis near the water surface. To date, however, most studies on Irgarol 

have focused on marine areas and toxicity tests with marine organisms (Mohr et al., 2009). 

Irgarol has been detected with increasing frequency at ecologically sensitive levels in 

coastal waters worldwide, as reviewed by Konstantinou and Albanis (2004). In ports and marinas 

in coastal waters, it has been detected in relevant effect concentrations of up to 4.2 μg/L (Basheer 

et al., 2002). Levels of up to 1.4 and 2.4 μg/L have been reported from UK marinas and 

freshwater sites (Thomas et al., 2002). In the United States, Irgarol and its major metabolite M1 

have been detected in the Chesapeake Bay and Florida (Hall and Gardinali, 2004). In the 

California marina study, Irgarol and M1 were detected in all 45 marina samples (Singhasemanon 

et al., 2009); Irgarol concentrations ranged from 12 to 712 ng/L, and M1 concentrations ranged 

from 1.6 to 217.1 ng/L. Higher concentrations of irgarol and M1 were found in salt water 

marinas. 

Although Irgarol was predicted to easily dissipate under natural conditions (Hall et al., 

2005), it is the most frequently detected antifouling biocide worldwide (Konstantinou and 

Albanis, 2004). Published values of the half-life of Irgarol in water are between 24 and 200 days 

(Mohr et al., 2009). 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

 EPA has expressed concern over the potential toxic effects of Irgarol on aquatic plants 

and algae (USEPA, 2003a). Compared to other triazines like atrazine and simazine, Irgarol is a 

more potent inhibitor of algal photosynthesis, and is 

therefore highly toxic to macrophytes, phytoplankton, 

and periphyton (Mohr et al., 2008). Irgarol is likely to 

be much less toxic to animals than flora (Mohr et al., 

2009). The main metabolite M1 is also toxic to aquatic 

plants and algae, but in many cases much more than 10 

times less toxic than Irgarol. 

What are Macrophytes, 

Phytoplankton, and 

Periphyton? 

A macrophyte is an aquatic 

plant that grows in or near 

water and is either emergent, 

submergent, or floating. 

Phytoplankton are planktonic 

algae that live in water bodies. 

Periphyton is a complex 

mixture of algae, 

cyanobacteria, heterotrophic 

microbes, and detritus that is 

attached to submerged 

surfaces in most aquatic 

ecosystems. 

Although Irgarol is formulated in AFSs to 

control periphyton on vessel hulls, the range of 

environmental concentrations measured in freshwater 

can be toxic to nontarget macrophytes. The results of 

the Mohr et al. (2009) study indicate that Irgarol is 

likely to have serious impacts on natural macrophyte 

communities at environmentally relevant 

concentrations. The fact that Irgarol accumulates in 

macrophytes, especially at lower concentrations, 

suggests the expected toxicity of Irgarol may be 

underestimated (Mohr et al., 2009). 

Irgarol concentrations at many of the marinas in the California study were high enough to 

be toxic to some phytoplankton and aquatic plants (Singhasemanon et al., 2009). For example, 

the range of observed Irgarol concentrations (12 to 712 ng/L) exceed aquatic benchmark values 

that are protective of 90 percent of aquatic plant species. The Irgarol metabolite M1 never 

exceeded the aquatic benchmark value (Singhasemanon, 2008). 

3.2.8.3 Zinc Biocides 

In recent years, there has been an increase in the registration of AFS products with zinc 

pyrithione (bis(N-oxopyridine-2-thionato)zinc(II)), also commonly known as zinc omadine, as 

the primary biocide (Singhasemanon et al., 2009). 

In a California marina study, dissolved zinc concentrations from paints containing zinc 

omadine ranged from 1.0–66.6 μg/L with a concentration distribution that was similar to 

dissolved copper (Singhasemanon, 2008). Dissolved zinc concentrations were much higher in 

saltwater marinas than brackish and freshwater marinas. Zinc concentrations did not exceed 

California Toxics Rule (CTR) fresh- and saltwater standards. If zinc pyrithione becomes more 

popular as an AFS biocide in the future (e.g., as a replacement for copper AFSs), the 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

contributions of zinc AFSs to the marina zinc load will increase and potentially lead to zincrelated toxicity (Singhasemanon et al., 2009). 

3.2.8.4 Emerging Biocides 

As mentioned in the introduction to this subsection, AFSs using copper-containing 

biocides are the most common substitutes for TBT. However, paint manufacturers continue to 

search for new antifouling biocides. One promising development is ECONEA, a metal-free 

biocide developed by a pharmaceutical company. According to the paint manufacturers, 

ECONEA is rapidly biodegradable and does not accumulate in the marine environment, and is 

reported by the manufacturer to very effectively control a wide range of invertebrate fouling 

organisms in significantly less amounts compared to conventional biocides. However, AFSs 

formulated with ECONEA have not entered the market, and independent testing data are not 

currently available. 

3.2.8.5 Biocide-Free (Nonbiocidal) AFSs 

In recent years, biocide-free coatings designed to prevent fouling growth from adhering 

to boat hulls have entered the market. Biocide-free coatings are designed to produce a slick 

surface that prevents fouling organisms from firmly adhering to the hull. Currently available 

nonbiocidal bottom coatings may be silicone-based, epoxy-based, water (urethane)-based, or 

polymer-based. They do not include biocidal components. Epoxy coatings are durable, and are 

expected to last for many years, but require frequent and aggressive cleaning (Johnson and 

Miller, 2002). The most commonly used nonbiocidal coatings are silicone elastomeric coatings, 

which are rubbery and are more easily nicked or abraded than epoxy, although recent advances 

have improved their durability. They are sometimes called “fouling release” coatings, because 

fouling growth is sheared off the hull once the vessel exceeds a certain speed (e.g., 20 knots). 

Movement of a foul-release-coated vessel through the water dislodges organisms that do adhere. 

The utility of these coatings depends on vessel speeds and the proportion of time the vessel is 

underway (rather than at dock). Foul-release coatings are typically more expensive than biocidal 

AFSs. Because of their expense and operational requirements, foul-release systems generally are 

not used on recreational vessels at this time. 

To date, nontoxic AFS alternatives have not been widely accepted in the boating 

industry, due to concerns about practicality and cost. If adopted, these alternatives would 

eliminate the leaching of biocides from marine antifouling paint, as well as biocide release 

during underwater hull cleaning. 

A number of projects are underway to develop new biocide-free AFSs. The European 

Commission is collaborating with industry with the goal of developing a nonbiocidal antifouling 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

coating that relies on nanostructuring to impede the adhesion of fouling organisms (Ambio, 

2008). The U.S. Navy is sponsoring research by University of Florida engineers to develop a 

biocide-free hull coating based on the geometry of shark skin scales. Chambers et al. (2006) 

provide a review of these and other biomimetic approaches to environmentally effective AFSs. 

Because nonbiocidal coatings do not affect fouling growth, they may need more frequent 

cleaning than biocide-based AFSs, and can be more effective when used with other practices 

designed to increase the amount of shearing and decrease exposure to fouling organisms during 

times of inactivity: using the vessel more often and/or operating it at higher speeds; storing it on 

land or on a hoist at the slip when not in use; and, surrounding the vessel with a slip liner and 

adding 10 to 15 percent fresh water to reduce salinity (Johnson and Gonzalez, 2006). 

3.2.8.6 BMPs 

The most effective way to reduce biocide emissions from AFSs on recreational vessels is 

by carefully selecting the AFS. The owner/operator should match antifouling performance with 

how the vessel typically operates. Choosing a nonbiocidal AFS can eliminate emissions from 

vessels that, for example, operate at high speeds when they are underway. Slow-release 

formulations or formulations with lower biocide content may also reduce the release of biocides 

into the aquatic environment. As noted previously, passive leaching accounts for most of the 

biocide release from recreational vessels, but biocide also could leach into the water body during 

underwater hull cleaning and AFS application and removal. 

In addition to AFS selection, other BMPs may be used to limit emissions of toxic 

components from AFSs. These BMPs include specifications for capturing and treating materials 

removed during underwater hull cleaning, properly managing wastes from AFS application 

processes, and capturing and appropriately disposing of old hull coating residue prior to 

repainting. When nonbiocidal coatings are used, companion strategies can be used to reduce 

fouling including slip liners, boat lifts, and frequent hull cleaning (Johnson and Gonzalez, 2006). 

BMPs for underwater hull cleaning must also address the potential introduction of aquatic 

nuisance species (ANS). EPA notes that small vessels are strongly suspected of contributing to 

the spread of numerous invasive species including zebra and quagga mussels. Prohibitions on 

biocide-containing AFSs could potentially exacerbate the spread of ANS as the toxicity of vessel 

hull coatings declines and as water quality improves as a result. 

Pollutants from passive leaching and hull cleaning can be reduced by implementing other 

BMPs, such as using nontoxic (or less toxic) antifouling paints to replace copper-based paints. 

Switching to nontoxic and less toxic antifouling paints will reduce the loading from both passive 

leaching and underwater hull cleaning. For example, if all new boats entering the Shelter Island 

Yacht Basin use nontoxic or less toxic coatings and existing boats replace copper coatings with 

nontoxic or less toxic coatings at the next routine hull-stripping (as assumed in their total 

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Chapter 3 – Analysis of Discharges and Potential Impact to Human Health and the Environment 

367 

maximum daily load), the basin’s water quality is expected to dramatically improve (CRWQCB, 

2005). Additionally, nontoxic or less toxic coatings will require companion strategies such as 

slip liners, boat lifts, and frequent hull cleaning to control fouling (Johnson and Gonzalez, 2006). 

3.2.8.7 Conclusion 

Antifouling systems currently used on the majority of recreational and commercial 

vessels are paints that prevent and retard fouling growth by leaching biocides, most frequently 

cuprous oxide, onto the hull. Biocides can enter a water body through passive leaching, 

underwater hull cleaning, hull painting, and AFS removal processes. Biocides leached from 

vessel AFSs can accumulate in the water of poorly flushed boat basins to levels that could harm 

marine life. Copper from vessel hulls in particular is a water quality concern in many nearcoastal waters of the United States, including the waters of Southern California, the Chesapeake 

Bay, Port Canaveral and Indian River Lagoon in Florida, and in various harbors in the state of 

Washington. Copper leaching from vessel hulls has also been reported as a problem in several 

European countries, including Sweden, the Netherlands, and Denmark. 

Concerns about impacts to aquatic ecosystems from both TBT and copper have led to the 

development of AFSs that use alternative biocides or are biocide-free. At this time, these 

alternatives are relatively costly and have not been widely accepted by boaters. Releases of 

biocidal components of AFS can be reduced by implementing BMPs, including the use of 

nontoxic (or less toxic) antifouling paints to replace copper-based paints. 

 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

CHAPTER 4 

POTENTIAL LARGE-SCALE IMPACTS OF STUDY VESSELS’ 

INCIDENTAL DISCHARGES TO HUMAN HEALTH AND THE 

ENVIRONMENT 

In Chapter 3, EPA described the variety of vessel discharges and the scope and 

magnitude of pollutants discharged by ‘study vessels.’ EPA discussed whether these discharges 

of pollutants exceeded a National Recommended Water Quality Criteria (NRWQC) at end-ofpipe or contained persistent bioaccumulative toxic (PBT) chemicals which could indicate a 

potential for environmental effects. Public Law (P.L.) 110-299 tasks EPA with assessing the 

potential for discharges incidental to the normal operation of vessels to pose a risk to human 

health, welfare, or the environment from all sizes of commercial fishing vessels and other 

nonrecreational vessels less than 79 feet in length. As part of this assessment, EPA used a 

screening-level model as a tool to evaluate the cumulative effects of discharges from a 

population of such vessels operating in a large receiving water body. 

EPA developed the screening-level water quality model to assess the impacts of vessel 

discharges on a hypothetical harbor environment1. For purposes of the model, EPA developed 

several vessel population scenarios that included multiple vessels from numerous vessel classes, 

such as fishing vessels, tour boats, water taxis, and tugboats discharging various waste streams 

(e.g., antifouling leachate, bilgewater, engine effluent, graywater). EPA then modeled numerous 

scenarios combining the different vessel populations in different hypothetical harbors to 

represent a range of environmental conditions potentially observed in harbors across the United 

States. 

 Due to the limitations of this screening-level model, EPA assumed that the 

background concentration for all analytes in the harbor water was zero. Although this assumption 

is likely unrealistic, removing other loading considerations from model calculations allowed 

EPA to evaluate whether incidental discharges from study vessels alone have the potential to 

exceed National Recommended Water Quality Criteria (NRWQC) in receiving waters without 

any additional sources of pollution. Vessel discharges may have a potential to contribute to 

water body impairment when vessel discharge pollutant concentrations exceed the NRWQC at 

end-of-pipe, depending on the quantity of pollutant in the discharge, what other potential sources 

of pollution are present, and the characteristics of the waters in which the vessel is operating. 

For example, if a group of vessels contributes a significant quantity of a given pollutant via a 

 

1

 For this analysis, the “harbor environment” refers to a large body of water that could potentially have 175 to 300 

commercial vessels simultaneously discharging. EPA assumed that the harbor area extended beyond the defined 

vessel docking area to include the surrounding water body with an estimated surface area ranging from one to three 

square miles. 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

discharge into a water body, the impact of the vessel discharge is more likely to contribute to a 

water quality exceedance. If a group of vessels contributes only a very small quantity of a given 

pollutant via a discharge, the impact of the vessel discharge is less likely to contribute 

meaningfully to a water quality exceedance. EPA believes that assessing the potential for vessel 

discharges to contribute to water-body impairment is best conducted on a site-specific basis and 

is beyond the scope of this screening-level analysis. 

Based on this assessment, EPA determined that incidental discharges from study vessels 

do not solely cause any NRWQC to be exceeded in the modeled hypothetical large estuaries and 

harbors. This determination suggests that these discharges alone are unlikely to cause 

impairments to relatively large water bodies. However, if a large water body already contains 

select pollutants, then vessels that contribute significant quantities of these pollutants might 

contribute to such an NRWQC exceedance. Furthermore, as discussed in Chapter 3, many 

pollutants detected in the vessel discharges were present at concentrations that exceed an 

NRWQC at the end of pipe, and therefore have the potential to negatively impact the receiving 

water on a more localized scale. Because the screening model assumes instantaneous and 

universal dilution in a large hypothetical harbor, the model is not designed to examine impacts 

on a local scale, in small water bodies with many vessels, or in water bodies with little to no 

flushing (i.e. dilution). These discharges may cause environmental concerns in areas such as 

small side embayments or marinas where flushing rates are low (see discussion in Section 4.6). 

As discussed above, EPA further notes that this model does not take into account any loadings 

from vessels that are not study vessels or other point/nonpoint sources that discharge pollutants 

that contribute to the loadings in the water body. 

For the purpose of this study, EPA selected a simple screening-level model to provide a 

coarse “big picture” assessment of the overall potential for discharges from study vessels to 

cause or contribute to an impact on human health, welfare, or the environment. Although a 

screening-level model has several limitations, it identifies any major water quality issues, 

provides valuable information on pollutants of concern, identifies data gaps, and serves as a 

starting point for any future site-specific studies that are beyond the scope and objectives of this 

study. 

The remainder of this chapter details EPA’s cumulative effects assessment and is 

organized as follows: 

 Section 4.1: Model Selection - Presents EPA’s rationale for selecting the Fraction of 

Freshwater Screening-Level Model for the analysis. 

 Section 4.2: Fraction of Freshwater Model - Describes the “fraction of freshwater 

model” and presents the equations and input parameters required for the screeninglevel analysis. 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

 Section 4.3: Vessel Discharge Loading Rates - Describes the methodology for 

developing the input parameters required to calculate the total analyte-specific 

loading rates for each vessel population scenario. 

 Section 4.4: Hypothetical Harbor - Describes the methodology for developing 

hypothetical harbor input parameters. 

 Section 4.5: Model Scenarios - Presents the 24 model scenarios represented in the 

model. 

 Section 4.6: Model Results - Presents the results from the “fraction of freshwater 

model.” 

 Section 4.7: Conclusions - Presents EPA’s conclusions on the potential for vessel 

discharges from study vessels to solely impact large-scale harbors or estuaries (e.g., 

to solely pose a risk to human health, welfare, and the environment). 

4.1 MODEL SELECTION

Study vessels discharge into coastal harbors throughout the United States. Estuarine 

models, which are commonly used to assess harbor water quality, consist of two primary 

components: hydrodynamics (i.e., water transport processes) and water quality. Estuarine models 

are generally classified into the following four levels according to the temporal and spatial 

complexity of the hydrodynamic component of the model: 

 Level I - Desktop screening models that calculate seasonal or annual mean 

concentrations based on steady-state conditions and simplified flushing time 

estimates. 

 Level II - Computerized steady-state or tidally averaged quasi-dynamic simulation 

models, which generally use a box or compartment-type network. 

 Level III - Computerized one-dimensional (i.e., estuary is well-mixed vertically and 

laterally) and quasi-two-dimensional (i.e., a link-node system describes estuary 

longitudinal and lateral mixing) dynamic simulation models. 

 Level IV - Computerized two-dimensional (i.e., represents estuary longitudinal and 

lateral mixing) and three-dimensional (i.e., represents estuary longitudinal, lateral, 

and vertical mixing) dynamic simulation models (EPA 2001). 

The sheer number of different coastal harbor environments potentially impacted by these 

vessels precludes using the more complex and data-intensive Level II, III, and IV models for the 

cumulative impacts analysis. For these reasons, EPA selected a Level I screening-level model, 

the “fraction of freshwater model,” for the environmental assessment of vessel discharges from 

study vessels. 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

In addition to coastal harbors, study vessels also discharge to freshwater environments 

such as the Great Lakes and major river systems (e.g., Mississippi River). The “fraction of 

freshwater model” is applicable to only estuarine or saltwater-influenced environments; 

therefore, the modeling approach presented in this chapter does not address the potential 

environmental impact of vessel discharges in completely freshwater environments. Additional 

screening-level modeling approaches would be required to assess possible impacts of vessel 

discharges in these environments. EPA assumes that discharges to freshwater systems represent a 

smaller percentage of the total load from study vessels based on hailing port information 

provided in the Marine Information for Safety and Law Enforcement (MISLE) database 

maintained by the U.S. Coast Guard. Based on these data, commercial fishing vessels are almost 

exclusively located along U.S. coastal waters, and only about a third of other nonrecreational 

vessels less than 79 feet in length cite an inland waterway as their hailing port. 

4.2 FRACTION OF FRESHWATER MODEL

The “fraction of freshwater model” is a series of equations that represent the harbor 

environment in zero dimensions and at a steady state (USEPA, 2001). These calculations are 

zero-dimensional in that they estimate concentrations at a given point in a water body within a 

specified, spatially homogenous volume. For example, the calculations assume instantaneous and 

homogeneous mixing of vessel discharges within the defined volume of a given harbor. It does 

not account for gradients of concentrations that would occur with distance from discharge 

source(s) such as plumes from vessels and other sources2. Specifying plumes and accounting for 

locations of numerous discharge sources would require a two- or three-dimensional model, 

which is beyond this Level I screening-level analysis. 

Steady state means that the calculations provide an instantaneous estimate of the 

concentration under the assumption of chemical and physical equilibrium. Chemical equilibrium 

means that the water body salinity and the vessel discharge analyte concentrations do not change 

over time, while physical equilibrium means that the volume of water in the water body, tides, 

currents, and vessel discharge flow rates do not change over time. The assumption is that every 

process occurs instantaneously; therefore, temporal variability is not a factor. Accounting for 

changes in tides, currents, river flow, vessel discharge flow rates, and discharge concentrations 

over time would require a dynamic model, which is beyond this Level I screening-level model. 

This aspect of the model may cause it to underestimate localized environmental impacts, 

 

2

 Discharge plumes can be highly structured, especially in low-flushing environments; therefore, the development of 

a worst-case scenario using a screening-level model is not entirely conservative due to the assumptions of 

instantaneous and homogenous mixing within the entire volume of the harbor. A true worst-case scenario would 

likely include the concentration of pollutants within a small area of the harbor due to minimal dispersion of 

discharge plumes across the harbor. It would also include background concentrations and take other pollutant 

loadings into account (e.g., sewage treatment facilities, recreational vessels and other large vessels, stormwater, 

agricultural runoff). 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

especially in areas with inadequate flushing. However, in estimating quantities of pollutants 

discharged from the various discharge types, EPA has tended to use conservative parameter 

estimates (i.e., estimates that may overstate the average value) for variables such as flow and 

pollutant concentration. 

The “fraction of freshwater model” calculates the analyte concentration in a harbor 

resulting from vessel discharges using the following four steps: 

 Step 1: Calculate vessel discharge analyte loading rates (Equations 4-1 and 4-2) 

 Step 2: Calculate the fraction of freshwater in the harbor (Equation 4-3) 

 Step 3: Calculate the harbor flushing time (Equation 4-4) 

 Step 4: Calculate the harbor analyte concentration (Equation 4-5) 

The following subsections describe the input requirements, assumptions, and calculations 

for each step in the “fraction of freshwater model.” 

4.2.1 Step 1: Calculate Vessel Discharge Analyte Loading Rates 

Analyte-specific total discharge loading rates (We) are required as input values in the 

“fraction of freshwater model” to calculate the instantaneous analyte concentrations in the harbor 

(Cx). In this analysis, analyte loading rates were based on the following four input parameters: 

 Average analyte concentrations for each vessel class discharge type; 

 Estimated flow rate for each discharge type within a vessel class; 

 Number of vessels per vessel class present in the harbor; and 

 Percentage of vessels per vessel class discharging each discharge type in the harbor 

(Equation 4-1). 

We,z = ( Ce,y,z* Qy,z * N,z* Py,z) Equation 4-1 

Where: 

We,z = Discharge loading rate for analyte e from vessel class z (mass/time) 

Ce,y,z = Average concentration of analyte e in discharge y from vessel class z 

(mass/volume) 

Qy,z = Flow rate for discharge y from vessel class z (volume/time) 

N,z = Number of vessels in vessel class z present in the harbor 

Py,z = Percentage of vessels in vessel class z discharging discharge y

EPA calculated the analyte-specific total discharge loading rate by summing the 

discharge loading rates for that analyte from each vessel class (Equation 4-2). Section 4.3

describes EPA’s methodology for calculating this loading rate in more detail. 

We = ( We,z) Equation 4-2 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

Where: 

We = Total discharge loading rate for analyte e from study vessel 

discharges (mass/time) 

We,z = Discharge loading rate for analyte e from vessel class z (mass/time) 

4.2.2 Step 2: Calculate the Fraction of Freshwater in the Harbor

The “fraction of freshwater model” estimates analyte concentrations in one dimension 

using information on freshwater inflow and by comparing salinity in the harbor with salinity in 

the seawater at the mouth of the harbor (USEPA, 2001). The fraction of freshwater (fx) at any 

location in the estuary is calculated as: 

fx = (Ss – Sx)/Ss Equation 4-3 

Where: 

fx = Fraction of freshwater at location x in the model harbor (unit-less) 

Ss = Seaward boundary salinity at the mouth of model harbor (PSU) 

Sx = Salinity at location x in model harbor (PSU) 

EPA states that this ratio (fx ) “...can be viewed as the degree of dilution of the freshwater 

inflow (as well as pollutants) by seawater” from tidal influx in the harbor (USEPA, 2001). 

4.2.3 Step 3: Calculate the Harbor Flushing Time

Harbor flushing time is defined as the amount of time required to replace the freshwater 

volume of the harbor by the river freshwater input. The flushing time (t) of the model harbor is 

calculated using Equation 4-4:

t = (V * fx)/Qfw Equation 4-4 

Where: 

t = Model harbor flushing time 

V = Volume of model harbor 

fx = Fraction of freshwater at location x in model harbor (unit-less) 

Qfw = Inflow of freshwater to model harbor from the model river 

(volume/time) 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

4.2.4 Step 4: Calculate the Harbor Analyte Concentration 

The concentration of an analyte at location x (Cx) is the analyte-specific total loading rate 

(We in mass/time) divided by the flow rate away from location x, described by the volume of the 

harbor (V) divided by the flushing time (t) (USEPA 2001): 

Cx = We/(V/t) Equation 4-5 

Where: 

Cx = Instantaneous analyte concentration at location x in model harbor 

(mass/volume) 

We = Analyte-specific loading rate (mass/time) as calculated under Step 1 

V = Volume of the model harbor as defined in Step 3 

t = Model harbor flushing time as calculated in Step 3 

4.3 VESSEL DISCHARGE LOADING RATES

Step 1 in the “fraction of freshwater model” calculates a range of analyte-specific total 

loading rates (We in mass/time) from fishing and nonrecreational vessels less than 79 feet based 

on the analyte concentration in a given discharge, the estimated flow rate for a given discharge, 

and assumptions on the number of vessels present in a harbor and percentage of vessels 

discharging each discharge type in the harbor. The following subsections present EPA’s 

methodology for developing the modeling input parameters to calculate the analyte-specific total 

discharge loading rate. 

4.3.1 Calculate the Average Analyte Concentrations

As described in Chapter 2, EPA collected wastewater characterization data for nine 

vessel discharges sampled from a total of 61 vessels (See Table 2.1). The objective of EPA’s 

sampling program was to provide information on the nature, type, and composition of discharges 

from representative single study vessels and study vessel classes. EPA calculated vessel-classspecific analyte concentrations by averaging all of the discharge effluent sampling data by 

discharge type and by analyte. Replicate samples from a single vessel were averaged together 

prior to calculating a vessel-class-specific average. Certain analytes were not detected above the 

sample reporting limit in some wastewater samples. To fully represent the variability of pollutant 

concentrations in vessel discharges, EPA included both nondetected and detected results in 

calculating average vessel-class-specific analyte concentrations. For nondetected results, EPA 

assumed the analyte concentration was equal to one-half the sample reporting limit for that 

analyte. EPA based this assumption on the expectation that the analyte was present in 

wastewater, albeit at a concentration less than the sample reporting limit. 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

4.3.2 Discharge Flow Rate Assumptions

EPA calculated discharge-specific flow rates for each of the 593 study vessels sampled 

based on the following information for each discharge type: 

 Known or estimated flow rates for the pump or mechanism controlling the discharge 

 Assumptions on the frequency of discharge 

 Assumptions on the duration of the discharge 

EPA estimated vessel-specific discharge flow rates based on data and field observations 

from EPA’s vessel sampling program, as well as information from secondary data sources. EPA 

developed frequency and duration assumptions based on interview responses from the vessel 

crew or observations from EPA’s vessel sampling team. For example, EPA reviewed interview 

responses from a tow/salvage vessel operator to estimate bilge discharges based on the 

observation that the bilge pump discharges 60 gallons per minute for an approximate duration of 

five seconds per pump-out with an average frequency of one pump out every 10-minutes. As 

another example, the frequency at which fishing vessels discharge fish hold water into a harbor is 

generally dictated by how often the vessel offloads its catch. EPA used vessel sampling team 

field observations to develop the discharge frequency for each fishing vessel subclass (Table 

4.3.1). 

In addition, many of the study vessel classes discharge different amounts in different 

seasons. For example, fishing vessels operate during certain times of the year to coincide with 

different peak fishing seasons. As a conservative estimate, to account for the seasonal nature of 

these discharge loadings, EPA developed vessel flows to represent the loading rate that would 

typically occur during peak vessel activity for each vessel class. Specifically, EPA calculated the 

loading rates to represent the summer (or peak) season for all vessels, which is the time of 

greatest fishing activity in the major harbors across the United States and is generally the peak of 

recreational and tourist activity. 4

 

 

3

 As previously discussed, EPA excluded the sampling data from the two recreational vessels in the model because 

these vessels are not study vessels. 

4

 Vessel flow rates presented in the screening-level analysis are not intended to be used to estimate annual loads. 

Additional seasonal considerations, such as the length of different fishing seasons, are required to calculate annual 

loads, which is beyond the scope of the screening-level analysis. 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

376 

Table 4.3.1. Offload Frequency by Fishing Vessel Subtype 

Fishing Vessel Subclass Frequency of Offloads1

Purse Seiners Daily 

Trollers Daily 

Gillnetters Daily 

Tenders Once every 2 days 

Longliners Once every 2 days 

Shrimpers Once every 3 days 

Trawlers Once every 3 days 

(1) Based on sampling team observation in the field. 

Table 4.3.2 provides examples of the known or estimated field data parameters and 

assumptions used to calculate the vessel-specific discharge flow rates for each discharge type. 

Where data parameter information were unknown, EPA used information from a similar vessel 

discharge type or used best professional judgment to estimate the required information. 

Appendix G provides a detailed description of the data and assumptions used to calculate the 

discharge-specific flows for each of these 59 sampled vessels. EPA averaged the vessel-specific 

discharge flows presented in Appendix G by vessel class and discharge type to calculate the 

vessel class-specific flow rates (Qy,z) used in the model (Table 4.3.3). 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human 

Table 4.3.2. Examples of Field Data and Assumptions for Flow Rate Calculations by Discharge 

Discharge 

Type Example Data Parameters Example Assumptions Example Discharge Flow Ca

Bilgewater - Flow rate of bilge pump 

- Frequency of bilge pump out - Duration of a single pump out 

- 12 volt bilge pump at 20 gpm1

- Discharged all year - 5 min to pump bilge - 2 pumpouts per day 

- 5 min to pump bilge - 1 pump per week - Discharged 365 days a year - 12 volt bilge pump at 20 gpm 20 gal per min X 5 min X 1 pump/7 days = 14

Deck Wash - Volume of water used 

during deck wash down - Frequency of deck washes - Duration of deck washes - Flow rate of garden hose or high-pressure sprayers used to wash decks 

- Garden hose flow rate is 11.67 gpm2

- 1 wash every 2 weeks - 15 minutes per deck wash 

- Cleaned with hose - 15 minute per deck wash - Garden hose flow rate is 11.67 gpm - 1 wash every 2 weeks 11.67 gal per min X 15 min X 1 wash/14 days (0.03 m3/day) 

Fish Hold - Volume of holding tanks 

- Volume of fish - Whether the tanks hold fish in water or ice - Amount of ice - Frequency of offloads - Length of fishing season 

- Density of fish is 0.9 kg/liter - Holding tank is 70% shrimp, 30% water3

- Ice tank holds 50% fish, 35% ice, 15% air4

- 5,000-gallon tank - 75% full at offload - Holding tank is 70%shrimp, 30% water - 1 offload every 3 days 5000 gal X 30% X 3/4 full X 1offload/3 days m3/day) 

Fish Hold Clean 

- Frequency of tank cleanings - Length of fishing season - Washed with garden hose 

- 30-minute wash for tenders and purse seiners - 15-minute wash for all other fishing vessels - Wash done after each offload - Garden hose flow rate is 11.67 gpm 

- 15-minute hose down after each offload - 1 offload every 3 days - Garden hose flow rate is 11.67 gpm 11.67 gal per min X 15 min X 1 wash/ 3 day = (0.13 m3/day) 

Graywater - Number of crew onboard 

- Types of graywater generated - Frequency of laundry washed - Frequency of showers 

- Laundry – front-load washer uses 25 gal/load - Laundry - standard washer uses 40 gal/load - Shower - 17.2 gal per shower5

- Shower - 0.8 showers per person per day5

- Sink - 30 min of sink use per crew per week - Sink - 2.2 gal per min in standard sink 

- 3 crew - 17.2 gal per shower - 0.8 showers per person per day 3 crew X 17.2 gal per shower X 0.8 showers pgal/day (0.16 m3/day) 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human 

378 

Table 4.3.2. Examples of Field Data and Assumptions for Flow Rate Calculations by Discharge 

Discharge 

Type Example Data Parameters Example Assumptions Example Discharge Flow Ca

Generator Engine 

- Engine type - Cooling system type - Hours of use per year 

- 2 gpm cooling flow for a standard generator6

- 17,000 hours over 15 years - 2 gpm cooling flow 2 gal/min X 60 min/hr X 17000hrs/15 years/36(1.41 m3/day) 

Propulsion Engine 

- Engine type - Cooling system type - Hours of use per year - Number of engines onboard 

- 1 gpm cooling water flow rate for outboard engine - 20 gpm cooling water flow rate for inboard engine6

- Cummins inboard 380hp diesel engine - 463 hours in last 2 years - 20 gpm cooling water flow rate 20 gal per min X 231.5 hours/year = 761.1 gal

Shaft Water 

- Duration of boat operation - 10 mL/min constant drip (3.8 gal/day 

drip)4

- operates 5 days/week - 10 mL/min constant drip (3.8 gal/day drip) 3.8 gal per day X 5 days/week = 2.71 gal/day 

(1) Estimate based on commonly used 12-volt bilge pumps. Flow rates ranged from 5 gpm to 30 gpm via Google. (2) EPA used http://www.uiweb.uidaho.edu/extension/lawn/Files/Garden_Hose.htm to calculate the average flow rate of a garden hose 

calculated the flow rate as the average flow for all three sizes of standard garden hose (1/2, 5/8, and 3/4 inches in diameter), assuming a 

and a hose length of 100 feet. (3) Based on data from one of the sampled vessels: 2,700 cubic feet per tank, 3 tanks (229,461.75 liters of tanks space), holds 325,000 l

liters of fish assuming density of fish is 0.9 kg/L). 163,798 liters of fish/229,461.75 liters of tanks space = 70% of fish. Assume remain(4) Based on sampling team observation in the field. (5) WaterSense Showerhead Factoids, Draft Date 7/27/09. 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

379 

Table 4.3.3. Vessel Flow Rates 

Vessel Class Vessel Subclass Discharge 

Flow Discharged to 

Harbor per Vessel 

(m3/day) 1

Fire Boat NA Deck Wash 0.0100 

Fire Boat NA Engine Effluent 36.3 

Fire Boat NA Fire Main Effluent 0.00 2

Fire Boat NA Generator Effluent 1.80 

Fishing Gillnetter Engine Effluent 14.9 

Fishing Gillnetter Fish Hold Effluent 0.800 

Fishing Lobster Boat Fish Hold Effluent 2.83 

Fishing Longliner Bilgewater 0.450 

Fishing Longliner Fish Hold Effluent 2.83 

Fishing Longliner 

Fish Hold 

Cleaning Effluent 0.00 2

Fishing Purse Seiner Engine Effluent 16.6 

Fishing Purse Seiner Fish Hold Effluent 16.3 

Fishing Purse Seiner 

Fish Hold 

Cleaning Effluent 1.07 

Fishing Purse Seiner Generator Effluent 1.41 

Fishing Shrimper Bilgewater 2.84 

Fishing Shrimper Deck Wash 0.344 

Fishing Shrimper Fish Hold Effluent 1.25 

Fishing Shrimper Graywater 0.00 2

Fishing Tender Vessel Fish Hold Effluent 19.3 

Fishing Tender Vessel 

Fish Hold 

Cleaning Effluent 0.660 

Fishing Trawler Deck Wash 0.344 

Fishing Trawler Fish Hold Effluent 1.25 

Fishing Trawler Fish Hold Clean 0.220 

Fishing Troller Deck Wash 0.470 

Fishing Troller Fish Hold Effluent 3.04 

Fishing Troller 

Fish Hold 

Cleaning Effluent 0.660 

Research NA Engine Effluent 0.0900 

Supply Boat NA Deck Wash 0.0300 

Tour Boat NA Bilgewater 0.0400 

Tour Boat NA Deck Wash 0.140 

Tour Boat NA Engine Effluent 42.2 

Tour Boat NA Fire Main Effluent 0.00 2

Tour Boat NA Generator Effluent 3.82 

Tow/Salvage NA Bilgewater 1.39 

Tow/Salvage NA Deck Wash 0.0240 

Tow/Salvage NA Engine Effluent 0.952 

Tugboat NA Deck Wash 0.0978 

Tugboat NA Fire Main Effluent 0.00 2

Tugboat NA Graywater 0.478 

Tugboat NA Shaft Water 0.0100 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

380 

Table 4.3.3. Vessel Flow Rates 

Vessel Class Vessel Subclass Discharge 

Flow Discharged to 

Harbor per Vessel 

(m3/day) 1

Water Taxi NA Bilgewater 0.130 

Water Taxi NA Deck Wash 0.0650 

Water Taxi NA Engine Effluent 39.8 

Water Taxi NA Generator Effluent 9.08 

Water Taxi NA Graywater 0.280 

NA – Not applicable. 

(1) EPA estimated discharge flow rates for each vessel class based on data and field 

observations from EPA’s vessel sampling program, as well as information from secondary 

data sources. EPA assumes that discharges not listed for a given vessel class are either not 

generated by a given vessel class or are discharged outside of the hypothetical harbor area. 

(2) These waste streams are all discharged in the harbor; however, the relatively small 

volume and infrequency of the discharge results in an insignificant daily discharge volume. 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

4.3.3 Number of Vessels Present in the Harbor 

The total number of vessels present in any given harbor and the distribution of vessels 

among the different vessel classes operating in that harbor vary significantly across the United 

States. The number and distribution of vessels among the different classes depend on factors 

such as the regional economic base (e.g., fishing versus recreation), size of the city supporting 

the harbor, and geographic location (e.g., Alaska versus Gulf of Mexico). To represent the 

variety of vessel combinations potentially present in a harbor, EPA developed the following 

three vessel population scenarios for the model: 

 Scenario 1: Fishing Harbor - A harbor where fishing is the primary economic driver 

in the region, and fishing vessels represent the majority of vessels present in the 

harbor5. 

 Scenario 2: Large Metropolitan Harbor - A harbor where there are nonrecreational 

study vessels associated with a large metropolitan city that would require a greater 

number of support vessels such as supply boats, tow/salvage vessels, and tugboats. In 

addition, EPA assumed that there would be a higher level of vessel activity within the 

hypothetical harbor compared to the activity assumed for Scenarios 1 and 3. Note that 

this screening analysis does not include large non study vessels such as container 

ships, tankers, bulk carriers, or other larger vessels, which would be present in almost 

any large port6. 

 Scenario 3: Recreational Harbor – A harbor where the primary economic driver is the 

tourist or recreation industry. Although recreational vessels are not study vessels, 

EPA assumed that a recreational harbor would have a high concentration of 

nonrecreational support vessels such as tow/salvage, tour boats, and water taxis 

associated with the regional recreational and tourist industry. However, as noted 

previously, this analysis does not consider discharges from non study vessels and 

other sources. 

EPA used data from the MISLE database maintained by the U.S. Coast Guard to develop 

the number of vessels present in the hypothetical harbors for the three scenarios and the 

distribution among the different vessel classes. The MISLE database includes a wide range of 

information regarding vessel and facility characteristics, accidents, marine pollution incidents, 

and other pertinent information tracked by the U.S. Coast Guard from investigation and 

 

5

 Charter fishing vessels are not modeled as part of this analysis. Charter fishing vessels are generally either 

manufactured or used primarily for pleasure, or leased, rented, or chartered to a person for the pleasure of that 

person. Many are not inspected by the US Coast Guard. These vessels are exempted from NPDES permitting 

requirements by the Clean Boating Act (P.L. 110-288). Other charter fishing vessels are inspected by the US Coast 

Guard. These inspected, non-recreational vessels are not exempted from NPDES by the Clean Boating Act, and are 

study vessels only if they are less than 79 feet. As a general matter, therefore, EPA anticipates that a significant 

portion of charter fishing vessels are not study vessels. 

6

 Due to time and resource constraints, EPA did not sample these large vessels for this study. Therefore, EPA did not 

calculate loadings from these larger vessels for this screening analysis. 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

382 

inspection activity. While MISLE represents the most comprehensive national dataset currently 

available, it may not capture the entire universe of study vessels that operate in U.S. waters (see 

Chapter 1 of this report for further discussion about the vessel universe in this study and the 

MISLE database). 

EPA identified and compiled hailing port and vessel class distribution data on the top 20 

hailing ports cited in the MISLE database. Based on the identified harbors, EPA selected 

representative harbors for each vessel population scenario to develop the vessel distributions in 

the model (see Table 4.3.4). 

Table 4.3.4. Vessel Population Scenario Representative Harbors 

Based on the Top 20 Hailing Ports Cited in the MISLE Database 

Top 20 Hailing Ports 

Cited in MISLE 

Vessel 

Population 

Scenario 1 

Fishing 

Harbor 

Vessel 

Population 

Scenario 2 

Large 

Metropolitan 

Harbor 

Vessel 

Population 

Scenario 3 

Recreational 

Harbor 

Boston, MA X 

Cordova, AK X 

Gloucester, MA X 

Homer, AK X 

Houma, LA X 

Houston, TX X X 

Juneau, AK X 

Ketchikan, AK X 

Key West, FL X 

Kodiak, AK X 

Miami, FL X X 

New Orleans, LA X X X 

New York, NY X X 

Norfolk, VA X 

Petersburg, AK X 

Portland, OR X X 

San Diego, CA X X 

San Francisco, CA X 

Seattle, WA X X 

Sitka, AK X 

For each representative harbor, EPA calculated the percentages of fishing vessels and 

non-fishing study vessels reported in the MISLE database (see Table 4.3.5, Table 4.3.6, and 

Table 4.3.7). EPA averaged the percentages of fishing and non-fishing vessels to develop the 

overall proportion of these vessel types for each vessel population scenario. 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

Table 4.3.5. Percentage of Study Vessels Present in 

Representative Fishing Harbor 

Hailing Port Percentage of Fishing 

Vessels

Percentage of 

Non-fishing Study 

vessels 

 New Orleans, LA 26% 74% 

 Seattle, WA 69% 31% 

 Houston, TX 56% 44% 

 Juneau, AK 82% 18% 

 Houma, LA 39% 61% 

 Cordova, AK 94% 6% 

 Homer, AK 82% 18% 

 Sitka, AK 76% 24% 

 Kodiak, AK 91% 9% 

 Portland, OR 51% 49% 

 Ketchikan, AK 62% 38% 

 Gloucester, MA 84% 16% 

 Petersburg, AK 93% 7% 

Average 70% 30% 

Source: MISLE database. 

Table 4.3.6. Percentage of Study Vessels Present in 

Representative Large Metropolitan Harbor

Hailing Port Percentage of Fishing 

Vessels

Percentage of 

Non-fishing Study 

vessels 

 New Orleans, LA 26% 74% 

 New York, NY 21% 79% 

 Miami, FL 43% 57% 

 Boston, MA 55% 45% 

 San Diego, CA 37% 63% 

Average 36% 64% 

Source: MISLE database.

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

Table 4.3.7. Percent of Study Vessels Present in 

Representative Recreational Harbor 

Hailing Port Percent of Fishing 

Vessels

Percent of 

Non-fishing Study 

vessels 

New Orleans, LA 26% 74% 

Seattle, WA 69% 31% 

New York, NY 21% 79% 

Houston, TX 56% 44% 

San Francisco, CA 64% 36% 

Miami, FL 43% 57% 

Norfolk, VA 28% 72% 

Houma, LA 39% 61% 

San Diego, CA 37% 63% 

Portland, OR 51% 49% 

Key West, FL 47% 53% 

Average 44% 56% 

Source: MISLE database.

EPA established the total number of vessels present in each vessel population scenario 

based on: 

 Field observations from EPA’s vessel sampling program. 

 Total vessel population data for the top 20 hailing ports as reported in the MISLE 

database. 

 An assumption that the hypothetical harbor is representative of up to 10 miles of 

shoreline. 

 An assumption that the vessel distributions reflect vessel populations during peak 

activity for each scenario (i.e., summer season during peak fishing, recreational, and 

tourist activity). 

Based on these assumptions, EPA selected a total vessel population of 175 vessels for 

Scenarios 1 and 3 and 300 vessels for Scenario 2 (see Table 4.3.8). Table 4.3.8 presents the 

distribution of vessels among the different vessel classes for each vessel population scenario 

developed using the vessel ratios discussed above, assumptions on the total vessel population, 

field observations, and best professional judgment. 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

385 

Table 4.3.8. Vessel Population Scenarios 

Vessel Class Vessel Subclass 

Vessel Population 

Scenario 1 

Fishing Harbor 

Vessel Population 

Scenario 2 

Metropolitan Harbor 

Vessel Population 

Scenario 3 

Recreational Harbor 

Fire Boat NA 1 5 1 

Fishing Gillnetter 12 10 9 

Fishing Lobster Boat 12 10 9 

Fishing Longliner 24 16 15 

Fishing Purse Seiner 12 10 9 

Fishing Shrimper 10 8 5 

Fishing Tender Vessel 20 10 9 

Fishing Trawler 20 16 13 

Fishing Troller 12 10 9 

Research NA 2 10 8 

Supply Boat NA 12 55 10 

Tour Boat NA 10 20 24 

Tow/Salvage NA 6 40 20 

Tugboat NA 12 60 10 

Water Taxi NA 10 20 24 

Total Number of Vessels 175 1 300 2 175 3

NA – Not applicable. 

(1) Fishing harbor - percentage of fishing vessels is 70%, percentage of non-fishing vessels is 30%. 

(2) Large metropolitan harbor - percentage of fishing vessels is 30%, percentage of non-fishing vessels is 70%. 

(3) Recreational harbor - percentage of fishing vessels is 45%, percentage of non-fishing vessels is 55%. 

4.3.4 Percentage of Vessels Discharging in the Harbor

In addition to the number of vessels present in the harbor, EPA also established the 

percentage of vessels within each vessel class and discharge type that discharge into the harbor. 

The purpose of this is to account for the fact that not all vessels within a vessel class discharge 

all waste streams. EPA developed and selected the percentage of vessels discharging to the 

harbor (see Table 4.3.9) based on interview responses and data collected during EPA’s vessel 

sampling program. EPA assumed all sampled vessels generate all discharges unless otherwise 

noted by the vessel operators as follows: 

 Vessel does not have the system or process responsible for the discharge (e.g., the 

vessel does not generate graywater as it does not have sinks, showers, or washing 

machines). 

 System has no discharge (e.g., vessel propulsion and generator engines are keelcooled). 

 Vessel typically discharges outside U.S. waters (e.g., fishing vessel washes decks 

after each catch at fishing grounds greater than 12 nautical miles from shore). 

Based on these criteria, EPA calculated the percentage of vessels (Py,z) in each vessel 

class that discharge each discharge type into the harbor using the following equation: 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

386 

Py,z= SampleNy,z / Sample Nz Equation 4-6 

Where: 

Py,z = Percentage of vessels in vessel class z discharging discharge y

Sample Ny,z = Number of vessels in vessel class z discharging discharge y 

from EPA’s vessel sampling program 

Sample Nz = Number of vessels from vessel class z from EPA’s vessel 

sampling program 

Appendix G includes the field data and assumptions used to develop the percentage of 

vessels input parameter (Py,z) for each vessel class and discharge stream. 

 

Table 4.3.9. Percentage of Vessels Discharging in the Harbor 

Vessel Class Vessel Subclass Discharge 

Percentage of 

Vessels 

Discharging Flow 

in Harbor 1

Fire Boat NA Deck Wash 100% 

Fire Boat NA Engine Effluent 100% 

Fire Boat NA Fire Main Effluent 100% 

Fire Boat NA Generator Effluent 100% 

Fishing Gillnetter Engine Effluent 80% 

Fishing Gillnetter Fish Hold Effluent 80% 

Fishing Lobster Boat Fish Hold Effluent 100% 

Fishing Longliner Bilgewater 33% 

Fishing Longliner Fish Hold Effluent 100% 

Fishing Longliner 

Fish Hold 

Cleaning Effluent 100% 

Fishing Purse Seiner Engine Effluent 40% 

Fishing Purse Seiner Fish Hold Effluent 100% 

Fishing Purse Seiner 

Fish Hold 

Cleaning Effluent 100% 

Fishing Purse Seiner Generator Effluent 40% 

Fishing Shrimper Bilgewater 50% 

Fishing Shrimper Deck Wash 80% 

Fishing Shrimper Fish Hold Effluent 80% 

Fishing Shrimper Graywater 100% 

Fishing Tender Vessel Fish Hold Effluent 100% 

Fishing Tender Vessel 

Fish Hold 

Cleaning Effluent 67% 

Fishing Trawler Deck Wash 80% 

Fishing Trawler Fish Hold Effluent 80% 

Fishing Trawler 

Fish Hold Clean 

Effluent 40% 

Fishing Troller Deck Wash 17% 

Fishing Troller Fish Hold Effluent 100% 

Fishing Troller 

Fish Hold 

Cleaning Effluent 33% 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

387 

Table 4.3.9. Percentage of Vessels Discharging in the Harbor 

Vessel Class Vessel Subclass Discharge 

Percentage of 

Vessels 

Discharging Flow 

in Harbor 1

Research NA Engine Effluent 100% 

Supply Boat NA Deck Wash 100% 

Tour Boat NA Bilgewater 67% 

Tour Boat NA Deck Wash 67% 

Tour Boat NA Engine Effluent 100% 

Tour Boat NA Fire Main Effluent 100%

Tour Boat NA Generator Effluent 67% 

Tow/Salvage NA Bilgewater 33% 

Tow/Salvage NA Deck Wash 100% 

Tow/Salvage NA Engine Effluent 83% 

Tugboat NA Deck Wash 100% 

Tugboat NA Fire Main Effluent 100% 

Tugboat NA Graywater 67% 

Tugboat NA Shaft Water 89% 

Water Taxi NA Bilgewater 75% 

Water Taxi NA Deck Wash 100% 

Water Taxi NA Engine Effluent 100% 

Water Taxi NA Generator Effluent 25% 

Water Taxi NA Graywater 25% 

NA – Not applicable. 

(1) The percentages of vessels discharging to the harbor were determined based on 

field observations of sampled vessels. As a conservative estimate, it was assumed that 

100% of vessels in sampled vessel classes with no information available discharge in 

the harbor. 

4.3.5 Vessel Discharge Loading Rates

EPA calculated the vessel class-specific loading rates for each analyte (We,z) using 

Equation 4-1 for each of the three vessel population scenarios described in Section 4.3.3. EPA 

then calculated the total analyte-specific load rates (We) for each vessel population scenario using 

Equation 4-2. Appendix G presents the total analyte-specific loading rates for each of the three 

vessel population scenarios represented in the model (i.e., fishing harbor, large metropolitan 

harbor, and recreational harbor). 

4.3.6 Dissolved Copper Loading Rates from Antifouling Paints

In addition to the loading rates calculated based on EPA’s vessel sampling program data, 

EPA also considered the additional dissolved copper load to receiving waters associated with 

antifouling paints used on vessel hulls. As described in Chapter 3, antifouling systems (AFSs) 

are designed to release biocide over time to retard growth and maintain a smooth underwater 

surface (Schiff et al., 2003). Copper oxide is the most common biocide added to AFSs to prevent 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

388 

biofouling organisms from attaching to the hull. Numerous studies have investigated the leaching 

rate of copper from both passive leaching and underwater hull cleaning (Thomas et al., 1999; 

Zirino and Seligman, 2002; Valkirs et al., 2003; Schiff et al., 2003). Based on estimates 

produced in these studies, EPA selected a dissolved copper leaching rate of 8.2 μg/cm2/day to 

estimate the additional dissolved copper load to the harbor from vessel AFSs. EPA estimated the 

average vessel length for each vessel class based on information available in the MISLE database 

and field observations from EPA’s vessel sampling program (Table 4.3.10). EPA assumed that 

the beam of the vessel beam (i.e., width) was equal to approximately one-third its length and 

used Equation 4-7 (Interlux, 1999) to estimate the hull surface area for each vessel class: 

Az = Lz * (Lz/3) * 0.85 Equation 4-7 

Where: 

Az = Hull surface area for individual vessels in vessel class z (area) 

Lz = Average length of vessels in vessel class z (distance) 

Table 4.3.10. Estimated Average Vessel Length 

by Vessel Class 

Vessel Class Vessel Subclass Vessel Length 

(feet) 1

Fire Boat NA 50 

Fishing Gillnetter 35 

Fishing Lobster Boat 35 

Fishing Longliner 35 

Fishing Purse Seiner 50 

Fishing Shrimper 50 

Fishing Tender Vessel 100 

Fishing Trawler 50 

Fishing Troller 35 

Research NA 40 

Supply Boat NA 50 

Tour Boat NA 50 

Tow/Salvage NA 40 

Tugboat NA 79 

Water Taxi NA 79 

NA – Not applicable. 

(1) - EPA estimated the average vessel length for each vessel 

class based on information available in the MISLE database 

and field observations during EPA’s vessel sampling 

program. 

EPA calculated the dissolved copper loading rate from AFSs for each vessel population 

scenario using Equation 4-8, and then added these loadings to the dissolved copper loading rates 

calculated in Section 4.3.5 for the other vessel discharges to determine the total dissolved copper 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

389 

load introduced into the harbor for each loading scenario7

. EPA calculated that AFSs contribute 

approximately 2.79 lbs/day of dissolved copper under Vessel Population Scenario 1 (fishing 

harbor), 4.86 lbs/day under Vessel Population Scenario 2 (large metropolitan harbor), and 2.63 

lbs/day under Vessel Population Scenario 3 (recreational harbor8

). Appendix G presents the total 

dissolved copper loading rates represented in the model. 

AFC Wcopper =  Nz * Az * 8.2 μg/cm2/day Equation 4-8 

Where: 

AFS Wcopper = AFS discharge loading rate for dissolved copper (mass/time) 

Nz = Number of vessels in vessel class z present in the harbor 

Az = Hull surface area for individual vessels in vessel class z (area) 

4.4 HYPOTHETICAL HARBOR 

Given the wide variety of coastal harbor environments potentially impacted by study 

vessel discharges, EPA developed several hypothetical harbors for the vessel discharge 

environmental assessment to represent a range of environmental conditions that could potentially 

be impacted. To develop input values that represented realistic environmental conditions, EPA 

identified and collected environmental data on eight harbors (Table 4.4.1) that represented a 

geographically and environmentally diverse group of water bodies, had the potential for a high 

density of study vessels, and received freshwater inflow from a major river system. 

Table 4.4.1. Harbors Selected for Model Input Parameter Development 

Harbor Name City Name State River Name 

Cohasset Harbor Boston Massachusetts Gulf River 

Dorchester Bay Boston Massachusetts Neponset River 

Auke Bay Juneau Alaska Mendenhall River 

Biscayne Bay Miami Florida Miami River 

Mobile Bay Mobile Alabama Tensaw, Blakeley, and Mobile River 

Yaquina Bay Newport Oregon Yaquina River 

Craford Bay Norfolk Virginia Eastern and Southern Branch Elizabeth River 

Eastern Channel Sitka Alaska Indian River 

The “fraction of freshwater model” requires the following four input parameters to define 

the water body characteristics: 

 

7

 Note that some hull cleaning methods can release a plume of antifouling paint, which contains copper in particulate 

form, in the water. The particulate copper can settle into the sediments and over time reenter the water body in the 

dissolved form. EPA did not include the potential dissolved copper load from particulate copper resulting from hull 

cleaning. 

8

 As noted above, these loading rates do not include the loading from nonstudy vessels. 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

390 

 Seaward boundary salinity at the mouth of the harbor (Ss) 

 Salinity at location x in the harbor (Sx) 

 Volume of the harbor (V) 

 Inflow of freshwater to the harbor (Qfw) 

EPA collected data on the four input parameters for the harbors listed in Table 4.4.1 and 

calculated a flushing time using Equation 4-4 in Section 4.2.3. Appendix G presents the 

environmental data identified by EPA for each harbor listed in Table 4.4.1. EPA selected the 

input parameters for the hypothetical harbors’ salinity, volume, and river flow based on the 

environmental data collected for the harbors with the minimum and maximum flushing times 

(Table 4.4.2). EPA assumed an average ocean salinity of 35 PSU for the salinity at the seaward 

boundary of the hypothetical harbor. 

Table 4.4.2. Hypothetical Harbor Input Parameters

Model Parameter Model Input 

Value Units 

Harbor Salinity (Sx) Minimum 26.1 PSU 

Harbor Salinity (Sx) Maximum 31 PSU 

Ocean Salinity (Ss) 35 PSU 

Harbor Volume (V) Minimum 3,090,000 m3

Harbor Volume (V) Maximum 38,500,000 m3

River Flow (Qfw) Minimum 352,000 m3/day 

River Flow (Qfw) Maximum 2,900,000 m3/day 

Using the input parameters in Table 4.4.2, EPA developed eight hypothetical harbors for 

the vessel discharge environmental assessment (see Table 4.4.3). For each harbor scenario, EPA 

calculated the fraction of freshwater (fx) and flushing time (t) using Equations 4-3 and 4-4 in 

Sections 4.2.2 and 4.2.3, respectively. Flushing times for the hypothetical harbors ranged from

less than a day (0.122 days or 2.9 hours) to 27.8 days. 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

391 

Table 4.4.3. Hypothetical Harbor Scenarios

Hypothetical 

Harbor Scenarios 

Harbor 

Salinity (Sx) 

Ocean 

Salinity (Ss) 

Harbor 

Volume (V) River Flow (Qfw) fx

Flushing 

Time 

(Days) 

Harbor Scenario 1 26.1 PSU 

 Sx Min 35 PSU 3,090,000 m3 

V Min 

352,000 m3

/day 

Qfw Min 0.254 2.23 

Harbor Scenario 2 26.1 PSU 

 Sx Min 35 PSU 3,090,000 m3 

V Min 

2,900,000 m3

/day 

Qfw Max 0.254 0.271 

Harbor Scenario 3 26.1 PSU 

 Sx Min 35 PSU 38,500,000 m3 

V Max 

352,000 m3

/day 

Qfw Min 0.254 27.8 

Harbor Scenario 4 26.1 PSU 

 Sx Min 35 PSU 38,500,000 m3 

V Max 

2,900,000 m3

/day 

Qfw Max 0.254 3.38 

Harbor Scenario 5 31 PSU 

 Sx Max 35 PSU 3,090,000 m3 

V Min 

352,000 m3

/day 

Qfw Min 0.114 1 

Harbor Scenario 6 31 PSU 

 Sx Max 35 PSU 3,090,000 m3 

V Min 

2,900,000 m3

/day 

Qfw Max 0.114 0.122 

Harbor Scenario 7 31 PSU 

 Sx Max 35 PSU 38,500,000 m3 

V Max 

352,000 m3

/day 

Qfw Min 0.114 12.5 

Harbor Scenario 8 31 PSU 

 Sx Max 35 PSU 38,500,000 m3 

V Max 

2,900,000 m3

/day 

Qfw Max 0.114 1.52 

4.5 MODEL SCENARIOS

EPA developed a total of 24 model scenarios (see Table 4.5.1) for the screening-level 

analysis based on the three vessel population scenarios and the eight hypothetical harbors 

discussed in Sections 4.3.3 and 4.4, respectively. EPA calculated the estimated harbor dilution 

for each model scenario using the following equation: 

Dx = (V/t)/(Qy,z * Ny,z* Py,z) Equation 4-9 

 

 Where: 

Dx = Harbor dilution at location x

V = Volume of model harbor 

t = Model harbor flushing time 

Qy,z = Flow rate for discharge y from vessel class z (volume/time) 

Ny,z = Number of vessels in vessel class z discharging discharge y 

Py,z = Percent of vessels in vessel class z discharging discharge y
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

392 

Table 4.5.1. Fraction of Freshwater Model Scenarios

Model 

Scenario 

Total Loading Rate (We) 

Scenario 

Hypothetical 

Harbor 

Scenario 

Dilution (Dx) 

Model Scenario 1 Vessels Population Scenario 1 Fishing Harbor Harbor Scenario 1 705 

Model Scenario 2 Vessels Population Scenario 1 Fishing Harbor Harbor Scenario 2 5,810 

Model Scenario 3 Vessels Population Scenario 1 Fishing Harbor Harbor Scenario 3 705 

Model Scenario 4 Vessels Population Scenario 1 Fishing Harbor Harbor Scenario 4 5,810 

Model Scenario 5 Vessels Population Scenario 1 Fishing Harbor Harbor Scenario 5 1,570 

Model Scenario 6 Vessels Population Scenario 1 Fishing Harbor Harbor Scenario 6 12,900 

Model Scenario 7 Vessels Population Scenario 1 Fishing Harbor Harbor Scenario 7 1,570 

Model Scenario 8 Vessels Population Scenario 1 Fishing Harbor Harbor Scenario 8 12,900 

Model Scenario 9 Vessels Population Scenario 2 Metropolitan Harbor Harbor Scenario 1 506 

Model Scenario 10 Vessels Population Scenario 2 Metropolitan Harbor Harbor Scenario 2 4,170 

Model Scenario 11 Vessels Population Scenario 2 Metropolitan Harbor Harbor Scenario 3 506 

Model Scenario 12 Vessels Population Scenario 2 Metropolitan Harbor Harbor Scenario 4 4,170 

Model Scenario 13 Vessels Population Scenario 2 Metropolitan Harbor Harbor Scenario 5 1,130 

Model Scenario 14 Vessels Population Scenario 2 Metropolitan Harbor Harbor Scenario 6 9,280 

Model Scenario 15 Vessels Population Scenario 2 Metropolitan Harbor Harbor Scenario 7 1,130 

Model Scenario 16 Vessels Population Scenario 2 Metropolitan Harbor Harbor Scenario 8 9,280 

Model Scenario 17 Vessels Population Scenario 3 Recreational Harbor Harbor Scenario 1 494 

Model Scenario 18 Vessels Population Scenario 3 Recreational Harbor Harbor Scenario 2 4,070 

Model Scenario 19 Vessels Population Scenario 3 Recreational Harbor Harbor Scenario 3 494 

Model Scenario 20 Vessels Population Scenario 3 Recreational Harbor Harbor Scenario 4 4,070 

Model Scenario 21 Vessels Population Scenario 3 Recreational Harbor Harbor Scenario 5 1,100 

Model Scenario 22 Vessels Population Scenario 3 Recreational Harbor Harbor Scenario 6 9,050 

Model Scenario 23 Vessels Population Scenario 3 Recreational Harbor Harbor Scenario 7 1,100 

Model Scenario 24 Vessels Population Scenario 3 Recreational Harbor Harbor Scenario 8 9,050 

As shown in Table 4.5.1, there are duplicate dilution factor values for different model 

scenarios (e.g., Model Scenarios 1 and 3 both have a dilution factor of 705). Hence, there are 

effectively 12 unique model scenarios and not 24 presented in this screening-level analysis. The 

duplicate dilution factors are an artifact of EPA’s decision to calculate dilution factors and 

instantaneous harbor concentrations using all combinations of the input parameters in Table 

4.4.2. In calculating the dilution factor, the volume of the harbor (V) cancels out of the dilution 

equation (Equation 4-9) and is not a consideration (see below). 

 Dx = (V/t)/(Qy,z * Ny,z* Py,z) 

 

 Where: 

(V/t) = (V/(V*fx/Qfw) 

(Qy,z * Ny,z* Py,z) = Total discharge flow from all vessels 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

393 

EPA used three total discharge flows ((Qy,z * Ny,z* Py,z) (i.e., vessel flows in a fishing 

harbor, large metropolitan harbor, and recreational harbor) and four different volume-toflushing-time (V/t) ratios (i.e., assumed two fx values in the model and two Qfw values) in the 

model. Section 4.6 discusses the results from the 12 unique model scenarios and presents the 

results of the duplicate scenarios as one result (i.e., harbor concentrations from Model Scenarios 

1 and 3). 

4.6 MODEL RESULTS

EPA calculated the instantaneous concentration (Cx) in the hypothetical harbor using 

Equation 4-5 presented in Section 4.2.4 for each of the 12 model scenarios defined in Table 

4.5.1. Appendix G presents the concentrations for all model scenarios for each vessel population 

scenario. EPA compared the instantaneous concentrations in the hypothetical harbor with the 

NRWQC to evaluate the potential for the cumulative effect of study vessel incidental discharges 

to impact aquatic life or human health. EPA determined that none of the modeled concentrations 

in the hypothetical harbor for the 12 scenarios exceeded an aquatic life or human health 

NRWQC. 

4.6.1 Dilution Factor Analysis

The model scenario dilutions factors calculated for the 12 unique scenarios ranged from 

494 to 12,900. EPA performed a sensitivity analysis to determine the dilution factor at which 

point NRWQC would be exceeded. EPA calculated the “tipping point” dilution in the 

hypothetical harbor where the instantaneous concentration in the harbor would equal the most 

stringent NRWQC for aquatic life or human health using the three vessel population scenario 

loading rates discussed in Section 4.3.5. Table 4.6.1 presents the tipping point dilution factors for 

the top 10 analytes with the highest dilution factor requirements to avoid exceeding an NRWQC. 

Based on the results of the dilution analysis, a harbor dilution factor of greater than 358 is 

required to avoid exceeding any NRWQC for aquatic life or human health, which is below the 

range of calculated model scenario dilution factors (i.e., 494 to 12,900). This sensitivity analysis 

also demonstrates that dissolved copper and total arsenic represent the most significant 

environmental risk from study vessels incidental discharges. These two analytes have relatively 

stringent range of dilution requirements depending on the vessel population scenario selected to 

avoid exceeding a NRWQC (i.e., dilution factors of greater than 144 to 266 for dissolved copper 

and 284 to 358 for total arsenic) and represent the highest dilution requirements for all the 

analytes detected in vessel discharges. Following dissolved copper, the required dilution factors 

drop off significantly with a dilution of greater than 33.7 required to avoid exceeding all other 

NRWQC with most of the remaining dilution factors below one. 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

394 

Table 4.6.1. “Tipping Point” Dilution Factors for Harbor Instantaneous 

Concentration to Equal the NRQWC Based on Vessel Population Scenario 

Loading Rates 1

Class Analyte 

Vessel 

Scenario 1 

Fishing Harbor 

Dilution (Dx) 

Vessel 

Scenario 2 

Metropolitan 

Harbor 

Dilution (Dx) 

Vessel 

Scenario 3 

Recreational 

Harbor 

Dilution (Dx) 

Metals Arsenic, Total 2 358 331 284 

Metals Copper, Dissolved 214 266 144 

Metals Arsenic, Dissolved 2 31.4 33.7 29.6 

Classicals Total Residual Chlorine 12.4 16.2 12.2 

Metals Aluminum, Total 6.77 5.15 4.83 

Classicals Sulfide 1.75 2.36 1.65 

Metals Selenium, Total 2 1.13 1.46 1.52 

VOC Benzene 0.756 1.57 1.34 

Metals Manganese, Total 0.684 0.983 1.04 

(1) Table includes only those analytes that required a dilution factor of greater than one to avoid 

exceeding a NRWQC. 

(2) EPA suspects a limited number of the samples analyzed for selenium (and even fewer for 

arsenic) for bilgewater, packing gland effluent, propulsion engine effluent, graywater and deck 

washdown water may have elevated measured concentrations due to positive interference. Despite 

these limited instances of interference, EPA believes the fish hold concentrations reasonably 

represent true effluent concentrations for the discharge (see discussion in Sections 3.1.3 and 3.2.4.1 

for further information). EPA considered these interferences when interpreting the potential for 

vessel discharges to pose a risk to human health, aquatic life, or the environment and determined 

that such cationic interference does not influence the major findings presented in the modeling 

analysis. 

4.6.2 Supplemental Model Run in Response to Comments

 In response to public comments submitted for the draft version of this report, EPA 

performed a supplemental model run using revised values based on information submitted by 

commenters to assess the impacts of these alternative values on the model results. EPA adjusted 

the model assumptions presented in Table 4.6.2 and recalculated the associated discharge flows 

and loads. EPA observed no significant change in model results based on the revised values. 

Table 4.6.3 presents the revised “tipping point” dilution factors for the supplemental model run. 

Table 4.6.2. Revised Model Assumptions

Vessel 

Class 

Vessel 

Subclass Discharge Old Assumption New Assumption 

Fishing Gillnetter Fish Hold Offloads daily Offloads once per five days 

Fishing Longliner Fish Hold Offloads once per two days Offloads once per five days 

Fishing Toller Fish Hold Clean Offloads daily Offloads once per seven days 

Fishing Toller Fish Hold Offloads daily Offloads once per seven days 

Fishing Toller Fish Hold 840 ft3 fish hold 595 ft3 fish hold 

Fishing Toller Fish Hold 5.5 tons of ice per offload 2 tons of ice per offload 

Fishing Toller Deck Wash 125 gallons per deck wash 50 gallons per deck wash 

Fishing Shrimping Bilge Water 150 gallons per minute bilge 

pump rate 

20 gallons per minute bilge 

pump rate 

Tour Boat NA Bilge Water 14.3 gallons per day 5 gallons per day 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

395 

Table 4.6.3. Supplemental Model Run “Tipping Point” Dilution Factors for 

Harbor Instantaneous Concentration to Equal the NRQWC Based on Vessel 

Population Scenario Loading Rates 1

Class Analyte 

Vessel 

Scenario 1 

Fishing Harbor 

Dilution (Dx) 

Vessel 

Scenario 2 

Metropolitan 

Harbor 

Dilution (Dx) 

Vessel 

Scenario 3 

Recreational 

Harbor 

Dilution (Dx) 

Metals Arsenic, Total 2 349 325 279 

Metals Copper, Dissolved 3 225 273 147 

Metals Arsenic, Dissolved 2 31.1 33.6 29.5 

Classicals Total Residual Chlorine 12.4 16.2 12.1 

Metals Aluminum, Total 6.77 5.10 4.79 

Classicals Sulfide 1.68 2.33 1.60 

Metals Selenium, Total 2 1.03 1.42 1.50 

VOC Benzene3 0.790 1.61 1.37 

Metals Manganese, Total 3 0.696 0.997 1.05 

(1) Table includes only those analytes that required a dilution factor of greater than one to avoid 

exceeding a NRWQC. 

 (2) EPA suspects a limited number of the samples analyzed for selenium (and even fewer for 

arsenic) for bilgewater, packing gland effluent, propulsion engine effluent, graywater and deck 

washdown water may have elevated measured concentrations due to positive interference. Despite 

these limited instances of interference, EPA believes the fish hold concentrations reasonably 

represent true effluent concentrations for the discharge (see discussion in Sections 3.1.3 and 3.2.4.1 

for further information). EPA considered these interferences when interpreting the potential for 

vessel discharges to pose a risk to human health, aquatic life, or the environment and determined 

that such cationic interference does not influence the major findings presented in the modeling 

analysis. 

(3) The revised model assumptions (see Table 4.6.2) did not significantly impact the total loads for 

this analyte; however, these assumptions lowered the total discharge volume from these vessels. 

Therefore, the dilution factors for the supplemental model run for this analyte are higher than the 

original model run due to the same mass loading rate being divided by a smaller total discharge 

flow. 

4.6.3 Loading Rate Analysis

 EPA compared the three analyte-specific loading rates used in the model with other 

known loading rates to provide perspective on their magnitude and on their relative contribution 

to the possible impairment of receiving waters (see Table 4.6.2 and Table 4.6.3). EPA selected 

the following loading sources for comparison: 

 Loads From Publicly Owned Treatment Works (POTW) 

 Dissolved copper loads discharged to the Shelter Island Yacht Basin 

 Estimated metal loading rates from urban stormwater 

EPA generated estimates for hypothetical medium-sized sewage treatment facilities with 

a discharge rate of 10 million gallons per day (MGD). These estimates were derived from the 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

396 

 

National Research Council’s 1993 report “Managing Wastewater in Urban Areas”. EPA 

calculated loadings by multiplying an effluent volume of 10 MGD times the low and high 

effluent concentrations for selected parameters using four types of wastewater treatment 

(chemically-enhanced primary plus biological treatment, primary or chemically enhanced 

primary plus nutrient removal, primary or chemically enhanced primary plus nutrient removal 

plus gravity filtration, or primary or chemically enhanced primary plus nutrient removal plus 

high lime plus filtration)9. Values presented in Table 4.6.2 present the lowest and highest 

derived loadings for these medium systems. EPA determined that the nutrient loads from the 

175 to 300 study vessels were comparable to the low end estimates for Ammonia as Nitrogen 

and total phosphorus, but notably lower than those from the high end treated effluent estimates 

from sewage treatment facilities. As noted above, the model nutrient loadings from study vessels 

do not include sewage discharges (which is likely a source of nutrients from these vessels)10, 

whereas these data are from POTW effluent, which has a significant sewage component. Table 

4.6.2 shows that a medium sewage treatment facility discharges a higher volume of metals than 

these 175 to 300 study vessels. Finally, these study vessels discharge comparable levels of 

BOD; though sewage treatment facilities are discharging a larger volume of effluent, they 

remove significant quantities of BOD from the effluent. On the other hand, study vessels’ 

incidental discharges are untreated waste, some of which has notably high BOD concentrations 

(e.g., fish hold effluent). 

EPA also obtained nutrient loading estimates from a sewage treatment facility with 

advanced nutrient removal capabilities to provide real world example nutrient loadings that may 

be associated with POTW discharges (Albert, 2007). This facility discharges approximately 40 to 

50 MGD. EPA determined that the nutrient loads (i.e., ammonia as nitrogen, nitrate/nitrite as 

nitrogen, total Kjeldahl nitrogen, and total phosphorus) from the 175 to 300 study vessels used to 

establish the vessel loads in the screening-level analysis were notably lower than the nutrient 

loads from this sewage treatment facility. It is important to note that these model nutrient loads 

do not include nutrient contributions from vessel sewage discharges (possibly a significant 

source of nutrients), as sewage discharges are excluded from the scope of P.L. 110-299. 

9

 A number of systems exist which are both smaller and larger than 10 MGD; for example, the Blue Plains POTW in 

Washington DC is the largest advanced wastewater treatment system in the word and discharges an average of 

approximately 330 MGD. The wastewater treatment facilities in nearby Arlington County discharge less than 40 

MGD. In comparison, the sewage treatment facility in Sitka, Alaska is designed to discharge only 1.8 MGD. 10 Sewage from vessels within the meaning of CWA section 312, which includes graywater in the case of 

commercial vessels operating on the Great Lakes, is exempt from the CWA definition of “pollutant”. 33 U.S.C. 

1362(6); 33 U.S.C. 1322(a)(6). As a result, vessel sewage discharges are not subject to NPDES permitting. Instead, 

Congress enacted a separate non-permitting scheme – CWA section 312 – to regulate the discharge of sewage from 

vessels. 

Under section 312 of the CWA, all vessels equipped with installed toilet facilities must also be equipped with an 

operable U.S. Coast Guard-certified marine sanitation device (MSD). 33 U.S.C. 1322(h). The provisions of section 

312 are implemented jointly by EPA and the Coast Guard: EPA sets performance standards for MSDs, and the Coast 

Guard is responsible for developing regulations governing the design, construction, certification, installation and 

operation of MSDs, consistent with EPA’s standards. 33 U. S.C. 1322(b). Current performance standards which 

apply to MSDs have standards for solids and fecal coliform. Generally speaking, most MSDs currently installed on 

study vessels are not designed to remove nutrients from sewage. 
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

397 

Therefore, these estimates are not a complete representation of vessel nutrient loadings; rather, 

they are merely an estimate of nutrient loadings from incidental discharges. 

As described in Chapter, 3 dissolved copper concentrations resulting from study vessels’ 

incidental discharges potentially pose a risk to aquatic life. A significant contribution of the 

dissolved copper load is from copper leaching from antifouling coatings on vessel hulls. In 2005, 

the California Regional Water Quality Control Board examined the dissolved copper loads to 

Shelter Island Yacht Basin from recreational vessel antifouling hull coatings and other source 

loads in support of a Total Maximum Daily Load (TMDL) analysis for the impaired water. EPA 

compared the dissolved copper loads from Shelter Island Yacht Basin TMDL to the vessel 

population scenario loading rates (Table 4.6.2). EPA determined that the estimated dissolved 

copper loads from 175 to 300 study vessels used in the model (i.e., 2.75 to 4.97 lb/day) were 

consistent with the combined dissolved copper loads from passive leaching and hull cleaning 

from 2,363 recreational vessels present in Shelter Island Yacht Basin (i.e., 12.7 lb/day). EPA also 

compared the model dissolved copper loads to the combined estimated contributions from urban 

runoff, background, and atmospheric deposition in Shelter Island Yacht Basin (i.e., 0.381 

lb/day). The model dissolved copper loads from hull leaching and other discharge streams were 

significantly larger than the other source contributions present in Shelter Island Yacht Basin, 

suggesting that dissolved copper from study vessels incidental discharges can represent a 

significant portion of the dissolved copper load in a water body. 

EPA also estimated metal loading rates for urban stormwater runoff based on reported 

loading rates from a 2001 literature study by Davis et al. and an assumed watershed area of 

approximately 17 square miles (watershed area determined from readily available information on 

watersheds’ drainage areas for the water bodies discussed in Table 4.4.1). As shown in Table 

4.6.2, EPA determined that urban stormwater likely represents a greater load of total copper, 

total lead, zinc, and cadmium to receiving waters than discharges from 175 to 300 study vessels. 

However, the model results indicate that dissolved copper loads from study vessels are 

significant.
Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human 

Table 4.6.4. Comparison of Model Loading Rates with Other Potential Point Source Loading Rates 

Model Loading Rates from 

Vessel Population Scenarios 1 Shelter Island Yacht Basin Loading R

Analyte 

Fishing 

Harbor 

(lb/day) 

Large 

Metropolitan 

Harbor 

(lb/day) 

Recreational 

Harbor 

(lb/day) 

POTW 

Loading 

Rates 

10 

mg/day2

(lb/day) 

POTW 

Loading 

Rates 

~40 

mg/day3

(lb/day) 

Passive 

Leaching 

(lb/day) 

Hull 

Cleaning 

(lb/day) 

Urban 

Runoff 

(lb/day) 

Backgrou

(lb/day) 

Ammonia as Nitrogen (NH3-N) 

8.52 6.07 5.07 8.35-41.7 36.2 NA NA NA NA 

Biochemical Oxygen Demand (BOD) 

635 481 392 250.4- 751.1 NA NA NA NA NA 

Nitrate/Nitrite (NO3 + NO2-N) 

0.127 0.203 0.102 NA 1,320 NA NA NA NA 

Total Phosphorus 13.8 8.91 7.74 8.35-125.2 22.0 NA NA NA NA Total Kjeldahl Nitrogen (TKN) 

97.8 68.5 59.0 NA 285 NA NA NA NA 

Arsenic, Total 0.0279 0.0359 0.0315 0.117-1.17 NA NA NA NA NA Cadmium, Total 0.000749 0.000657 0.000551 0.117- 0.609 NA NA NA NA NA Copper, Dissolved 2.88 4.97 2.75 NA NA 12.1 0.604 0.181 0.181 Copper, Total 0.158 0.179 0.165 1.25-4.17 NA NA NA NA NA Lead, Total 0.0108 0.0154 0.0142 1.50-4.01 NA NA NA NA NA Zinc, Total 0.758 0.613 0.516 3.34-9.35 NA NA NA NA NA NA- Not available. (1) Model loading rates do not include contributions from study vessel sewage waste streams as these discharges are not covered under P.L. 110-299. 

(2) Estimated loadings from concentrations for medium sewage treatment facilities (~10 mg/d) derived from concentrations presented in National Res(3) Estimated nutrient loads from an actual sewage treatment facility with advanced nutrient removal capabilities with an average of approximately 40 (4) Estimated point source loads to Shelter Island Yacht Basin (California Regional Water Quality Control Board, 2005). (5) Passive leaching and hull cleaning loading rates were based on an assumption of 2,363 recreational vessels present in Shelter Island Yacht Basin. 

(6) Urban runoff contributions were based on a watershed area of 0.84 mi2 draining to Shelter Island Yacht Basin, and the atmospheric deposition loadShelter Island Yacht Basin of 0.27 mi2. (7) Estimated urban stormwater loads were based on loading rates presented in Davis et al., 2001 and an assumed watershed area of 17 mi2 (MA DEP

The loading rates presented are average annual daily loads. 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

4.7 CONCLUSIONS

This screening-level analysis evaluated the potential for discharges incidental to the 

normal operation of vessels to pose a risk to human health, welfare, or the environment in large 

water bodies. The analysis includes all sizes of commercial fishing vessels and other 

nonrecreational vessels less than 79 feet in length. EPA selected a Level I screening-level model 

(see Section 4.1) to help assess the potential impacts from study vessels’ incidental discharges 

and modeled several scenarios combining different vessel assemblages and different hypothetical 

harbors to represent a range of environmental conditions potentially observed in harbors across 

the United States. The modeled constituent concentrations from the discharges into the 

hypothetical harbor for the 12 scenarios did not exceed an aquatic life or human health NRWQC 

solely from study vessel discharges; however, the model did not account for background 

loadings. Certain pollutants (e.g., arsenic and dissolved copper) are more likely to contribute to a 

water quality criterion being exceeded under real-world conditions. Furthermore, the model’s 

capabilities do not allow for the evaluation of whether these discharges cause localized impacts 

(see Section 4.2), nor do they allow an analysis of issues such as bioaccumulation or persistent 

toxicity in water bodies or accumulation of pollutants in sediments. 

As discussed in the introduction, EPA’s fraction of freshwater analysis is only intended to 

evaluate environmental effects from vessel discharges at the water body or harbor scale and does 

not address the environmental effects that could potentially occur in localized areas such as small 

side embayments or marinas. As discussed in Section 4.1, the “fraction of freshwater model” 

does not describe concentration gradients within plumes from vessels. Accounting for spatial and 

temporal variability in a harbor would require a more data intensive dynamic model and is 

beyond a Level I screening-level model. EPA acknowledges that incidental discharges from 

study vessels may pose an environmental threat in confined areas with low receiving water 

flushing rates and a large population of vessels. In the dilution analysis discussed in Section 4.6, 

EPA determined that a “tipping point” dilution factor of greater than 358 would be required to 

avoid exceeding any NRWQC based on the estimated loading rates used in the model (see Table 

4.6.1). These results suggest that the loading rates represented in the model may have the 

potential to cause a water quality criterion to be exceeded on a localized scale either before 

complete mixing is achieved in the receiving water (i.e., as the plume dissipates) or if the 

discharges are released in a receiving water with a dilution potential of lower than 358. The 

model further suggests that these vessels may be more likely to contribute to an NRWQC being 

exceeded (particularly where the diluting factor is high for a pollutant) where the ambient 

concentrations or other sources of pollutants are significant. On the other hand, EPA has tended 

to use conservative estimates of some parameters (e.g., flow and pollutant concentrations) in its 

modeling. 

In the “fraction of freshwater model,” EPA calculated the instantaneous concentration in 

the hypothetical harbor based solely on pollutant contributions from discharges from study 

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Chapter 4 – Potential Large Scale Impacts of Study Vessels Incidental Discharges to Human Health and the Environment 

400 

vessels. Although the assumption that harbor background pollutant concentrations are zero for all 

analytes is likely unrealistic, removing other loading considerations from model calculations 

allows for the assessment of the potential for study vessel incidental discharges alone to cause an 

NRWQC to be exceeded. Although the “fraction of freshwater model” results suggest that study 

vessels’ incidental discharges will not cause an environmental impact on their own, the fact that 

pollutants are present in the vessel discharges at concentrations that exceed the NRWQC at endof-pipe may support a determination that some of these discharges have the potential to 

contribute to a water quality standard exceedence. 

Based on the dilution results, the two pollutants that represent the greatest risk for 

contributing to an environmental effect or water body impairment are total arsenic and dissolved 

copper. EPA determined that the loading rates from the metropolitan harbor (i.e., Model 

Scenarios 9 and 11) were at the greatest risk of exceeding the NRWQC for these pollutants. 

However, the minimum dilution factors required to avoid exceeding the NRWQC for these 

pollutants (i.e., 284 for total arsenic and 144 for dissolved copper in the recreational harbor) are 

similar to the lowest dilution factor represented in the hypothetical harbor scenarios (i.e., 494). 

This suggests that study vessel’s incidental discharges may be contributing a significant load of 

these two pollutants to the water body. Given the right environmental conditions (i.e., low 

flushing) or pollutant loadings from other point/nonpoint sources (e.g., recreational vessels, large 

commercial vessels, stormwater runoff, and industrial and municipal point sources), the 

concentrations of these pollutants may have a potential to cause or contribute to an exceedence 

of the NRWQC, regardless of vessel class distributions. These results are consistent with realworld observations that metals are frequently associated with vessel discharges in concentrations 

of potential environmental concern (see Chapter 3). In particular, environmental impacts from 

dissolved copper leaching from hull coatings has been well documented in low flushing 

environments such as Shelter Island Yacht Basin near San Diego, California, and Marina Del 

Rey Harbor in Los Angeles, California. 

Nutrients from study vessels’ incidental discharges represent another pollutant class with 

the potential to contribute to deleterious environmental effects. Nutrients differ from other 

pollutants present in vessel discharges in that the environmental effects are driven by sitespecific environmental conditions (e.g., water temperature, types of algae present, limiting 

nutrient). For example, the estimated nutrient loads used in the modeling analysis may contribute 

to an environmental effect in one water body, but not another depending on a variety of factors 

that control eutrophication. EPA has not developed an NRWQC for nutrients; however, some 

states have established water-body-specific or state-wide standards for nutrients based on sitespecific evaluations. 
Chapter 5 - Summary of Findings 

CHAPTER 5 

SUMMARY OF FINDINGS 

This chapter summarizes the major findings of EPA’s detailed analyses described in 

Chapters 1, 3, and 4. It describes findings on vessel classes that are covered by this study. It 

summarizes major findings from the characterization of select discharges from the study vessels, 

including EPA’s interpretation of these findings in the context of the level of potential risk from 

these pollutant loadings. Additionally, it discusses major findings of EPA’s assessment of the 

predicted impacts of these discharges to a hypothetical harbor. This chapter also briefly 

summarizes possible benefits to human health, welfare, and the environment from reducing, 

eliminating, controlling, or mitigating discharges from study vessels. 

5.1 SUMMARY OF CLASSES OF VESSELS COVERED BY THIS STUDY

EPA estimates there is a population of approximately 140,000 study vessels. According 

to the U.S. Coast Guard’s Marine Information for Safety and Law Enforcement (MISLE) 

database, there are approximately 70,000 commercial fishing vessels operating in the United 

States. These vessels represent the largest category of study vessels. Passenger vessels comprise 

the second highest number of vessels within the study population, with approximately 21,000 

vessels. These vessels are further classified by subtypes according to the types of activities in 

which they are involved, such as diving vessels, charter fishing vessels, ferries, harbor cruise 

vessels, and sailing vessels. The study population also includes over 11,000 utility vessels, 

including tugs/towing vessels, school ships, research vessels/ships, mobile offshore drilling units, 

offshore vessels, offshore supply vessels, oil recovery vessels, and industrial vessels. Other 

vessel categories such as freight barges (approximately 8,000 vessels), tank barges 

(approximately 900 vessels), freight ships (approximately 800 vessels), unclassified public 

vessels (approximately 600 vessels), and tank ships (approximately 200 vessels) account for the 

remainder of other non-recreational study vessels. An additional 27,375 vessels in the MISLE 

database are also believed to be study vessels; however, the database does not indicate their type 

of service. See Chapter 1 for additional discussions of the study vessel and recreational vessel 

populations. 

5.2 SUMMARY OF EFFLUENT CHARACTERIZATION OF SELECT DISCHARGES 

FROM THE STUDY VESSELS

The major findings of EPA’s analysis of the vessel discharge characterization data for 

study vessels are summarized below. For this study, EPA sampled 61 vessels in nine states 

generating over 22,000 data points. EPA tested for 301 analytes and detected 154 of these 

analytes in at least one sample; therefore, 158 of the tested analytes were never found in the 

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Chapter 5 - Summary of Findings 

discharges. Section 5.2.1 discusses the estimated volumes of the discharges and Section 5.2.2 

discusses the detected pollutants that may have the potential to pose a risk to human health or the 

environment. See chapters 3 and 4 for more technical, in-depth discussions of these results. 

5.2.1 Estimated Volumes of Select Discharges from the Study Vessels

EPA estimated volumes for each discharge from the study vessels based on data and field 

observations from EPA’s vessel sampling efforts, as well as information from secondary data 

sources. Discharge volumes are important to both characterize the discharge and to analyze the 

potential risk of the pollutant concentrations discharged from vessels. EPA also used these 

discharge volumes to calculate flow rates for the modeling of pollutant loadings to a hypothetical 

harbor in Chapter 4. 

Bilgewater generation rates are highly variable. EPA observed as little as 2 gallons of 

bilgewater discharged from a tow/salvage vessel following a tow activity to as much as 750 

gallons of bilgewater discharged during the daily bilge pump-out from a 62-foot shrimp boat 

from the Gulf of Mexico. In general, based on observations from dozens of vessel operations, 

EPA estimates that small (less than 79 feet), nonrecreational vessels typically generate between 

10 and 15 gallons per day (gpd) of bilgewater. 

Stern tube packing gland effluent is by nature limited to the small amount of water 

needed to provide cooling and lubrication to the gland around the drive shaft. The range in 

estimated discharge for stern tube packing gland effluent is approximately 4 to 8 gpd. 

For deckwash water from tour boats, water taxis, and tow boats, EPA estimates a 

discharge volume of between 20 and 30 gpd. Fishing boats are estimated to generate more 

deckwash water and the volumes generated vary with the type of boat. Trollers, trawlers, 

gillnetters, and purse seiners may wash their decks three to four times per day while fishing, 

producing as much as an estimated 750 to 900 gpd of deckwash water. 

The volume of fish hold effluent generated by a fishing vessel depends on the size of the 

vessel and the method used to keep the product fresh. Smaller fishing vessels such as small 

salmon trollers or long-liners may discharge an estimated fish hold volume ranging from 70 to 

200 gpd. Mid-size fishing vessels, such as gill netters and purse seiners found in Alaska and 

shrimp boats in the Gulf of Mexico may discharge approximately 333 to 1,000 gpd. Larger 

fishing vessels such as off-shore trawlers found in New England and tenders found in Alaska, 

however, can have refrigerated seawater holding tanks or ice hold tanks as large as 15,000 

gallons. These vessels are expected to offload seafood and discharge the fish hold effluent every 

three to five days, resulting in an estimated flow rate ranging from 900 to 2,000 gpd. EPA 

estimates the volume of fish hold cleaning effluent discharged by certain fishing vessels to be 

anywhere from 300 to 400 gallons per cleaning, which occur typically every three to five days 

402 

 
Chapter 5 - Summary of Findings 

when the fish holds are emptied (discharge volumes range from an estimated 60 to 200 gpd 

depending on frequency of offloading). 

Fisherman unloading their catch to the dock from a trawler (dragger) in Massachusetts. 

Graywater volumes also vary considerably depending on the class of vessel and its use, 

size, number of crew and passengers onboard, and types of graywater-generating activities 

onboard (e.g., galleys, sinks, showers, and washing machines). For example, EPA estimated that 

tugboats, some of which provide living quarters for three to five crew members, generate 

approximately 130 gpd of graywater. Water taxis typically have considerably more people 

onboard, but less graywater is generated per person because the discharge is typically limited to 

bathroom sinks with an estimated 75-gpd discharge. Graywater generation on commercial 

fishing boats might range from a few to hundreds of gpd, depending on the length of the trip and 

the size of the crew. 

Finally, the volume of engine effluent discharged depends on the type of engine and 

power level of operation. Vessels with outboard propulsion engines are estimated to discharge 

between 1 to 2 gallons per minute (gpm) of raw cooling water per engine. The cooling water 

discharge rate from inboard marine diesel engines varies based on power levels, but typically 

averages around 20 gpm for the study vessels. Marine diesel generator sets require 

approximately 5 to 6 gpm of cooling water for smaller units, and up to 20 to 25 gpm of cooling 

water for larger marine generator sets. Daily discharge rates for these engines are a function of 

the daily operating time. 

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Chapter 5 - Summary of Findings 

5.2.2 Analytes of Potential Risk in Select Discharges from Study Vessels 

EPA compared the measured concentration of any given analyte to its most stringent 

benchmark1

 (Table 3-1) as one means to identify pollutants in vessel discharges that may have a 

potential to pose a risk to human health or aquatic life. EPA divided the concentration of an 

analyte by its corresponding benchmark to calculate a potential hazard quotient (PHQ). If a PHQ 

is less than 1, there is less of a concern that the pollutant in the discharge will have impacts to 

human health or aquatic life. An exception to this determination is when the pollutant is 

persistent and/or bioaccumulative and may increase in concentration within the ecosystem food 

chain to harmful levels. If a PHQ is equal to or greater than 1, then there is more of a concern. 

However, PHQs of greater than 1 do not provide conclusive evidence of risk to human health or 

the environment for the following reasons: 

1. Samples were collected at the “end of pipe” as the vessels discharged into larger waters 

(e.g., harbors, rivers). However, the discharge is typically diluted in the water body. 

Therefore, accounting for possible dilution in the receiving water could result in ambient 

PHQ of less than 1 (except possibly small harbors or marinas with limited or no flushing 

or where the receiving water PHQ is already above 1 due to other factors). 

2. The benchmarks used to evaluate the potential for risk were always the most protective, 

even if it was not the most commonly applicable screening benchmark for that particular 

analyte. Given this, the potential for risk might be over-stated. 

3. The surrounding ambient water or source water (vessel service2 or city water supply) 

used in the vessel systems that generated these discharges (e.g., engine cooling water 

drawn from ambient water or potable water used for deck cleaning) may already contain 

high concentrations of some of these analytes. In these instances, a high analyte 

concentration measured at the “end of pipe” may not originate from vessel activities, but 

rather from the water used in these operations. 

EPA made the following general observations based on its review of the vessel discharge 

data (see Chapter 3 for EPA’s detailed analysis of the data): 

 Dissolved copper was the analyte detected in vessel discharges at concentrations that 

consistently posed the greatest potential risk for local impacts and for contributing to 

exceedances of water quality standards in larger water bodies. Copper is a heavy metal 

that can restrict the growth and reproduction of plants and algae and can produce both 

acute (short-term) and chronic (long-term) toxic effects on reproduction, growth, and 

 

1

 To provide a context for the level of contaminant concentrations presented, EPA used National Recommended 

Water Quality Criteria (NRWQC) and several other benchmarks as a preliminary screen for all discharge data with 

the potential to cause or contribute to the nonattainment of a water quality standard in a given receiving water body. 2

 Service water here means the vessel potable water supply. For study vessels, vessel service water generally 

originates from municipal water supply rather than produced on board. 

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Chapter 5 - Summary of Findings 

survival in fish and shellfish. Prolonged exposure to elevated copper concentrations can 

lead to long-term liver and kidney damage in humans. Concentrations of dissolved 

copper exceeding the most protective screening benchmark were found in at least some 

samples for every sampled discharge type, except for outboard engine and generator 

engine effluents. 

Dissolved copper was detected at the highest concentrations in the deck washdown, 

graywater, fish hold, and bilgewater discharges from most vessel classes, particularly 

utility vessels (e.g., towboats, supply boats). PHQs for mean dissolved copper 

concentrations ranged from a low of 1.1 in graywater discharges to a high of 

approximately 200 in fish hold effluent. Based on concentration and average discharge 

volume, deck washdown and fish hold discharges contribute the most dissolved copper. 

Copper is released (leached) from antifouling hull coatings used on certain vessels to 

prevent buildup of organisms such as barnacles and algae. Copper can also be released 

via underwater hull cleaning, hull coating removal operations, and paint application. 

Although copper antifouling discharges were not measured, previous studies have shown 

it can be a major contributor to copper concentrations in harbors, especially marinas with 

large vessel populations (see Section 3.2.8.1). 

Average ambient dissolved copper concentrations in the harbors sampled in this study 

were also slightly higher than the most protective benchmark (mean PHQ of 1.6). 

However, discharge concentrations still exceeded the benchmark even after subtracting 

the potential contribution of copper from ambient waters. 

 Total arsenic3

 concentrations in vessel discharges were also notably higher than the most 

protective screening benchmark. In samples where arsenic was detected, PHQs for mean 

total arsenic concentrations ranged from a low of 110 in graywater discharge to a high of 

2,900 in bilgewater discharge. Arsenic is a metalloid (a nonmetallic element with some 

metal properties) that is easily absorbed by aquatic plants, algae, fish, and shellfish. 

Arsenic can cause a variety of acute and chronic toxic effects in aquatic organisms, as 

well as in humans who ingest arsenic via drinking water and contaminated seafood. 

Arsenic is a known carcinogen, and prolonged high exposures via ingestion can cause 

cancer, skin irritation, kidney and liver damage, and neurological damage. 

Despite the high potential toxicity of total arsenic, the risk posed to aquatic life is lower 

than what is suggested by this analysis for two reasons. First, the screening benchmark 

for total arsenic is a human health criterion to prevent cancer-causing agents in drinking 

water and is over 100 times lower than that of any other metal in this study. The high 

 

3

 See discussion in Section 3.1.3 regarding potential positive interference which may have resulted in elevated 

measured concentrations of arsenic for a subset of samples. 

405 

 
Chapter 5 - Summary of Findings 

total arsenic PHQs in vessel discharges are the result of this low benchmark for human 

health, which is 2,000 times lower than the dissolved arsenic benchmark that is based on 

chronic, long-term toxicity to saltwater aquatic life. Many of the waters where many 

study vessels operate, particularly for certain vessel types such as commercial fishing 

vessels, are not typically used as drinking water sources (i.e., ocean and coastal waters). 

However, some waters where study vessels operate (e.g., the Mississippi River) do serve 

as drinking water sources and high arsenic loadings in these waters could contribute to 

human health concerns. 

Second, between 20 to 100 percent of the total arsenic measured in the various vessel 

discharges can be attributed to ambient water that is used as source water for vessel 

systems. Vessel discharges most influenced by ambient total arsenic concentrations 

include those from stern tube packing glands, outboard engines, and firemain systems. 

However, less than half of the total arsenic measured in bilgewater, deckwash, and fish 

hold discharges appears to be contributed by concentrations in ambient water, indicating 

that these discharges potentially contribute to arsenic toxicity in receiving waters. Based 

on concentration and average discharge volume, deck washdown and fish hold discharges 

appear to contribute the most total arsenic. 

 Total aluminum concentrations exceeded benchmark concentrations in at least some 

samples for all discharge types; however, some of the aluminum concentrations in the 

discharge may be due to background concentrations (e.g., not added to the discharge by 

the vessel). Average PHQs for total aluminum ranged from a high of 39 in deck 

washdown discharge to a low of 1.8 in outboard engine effluent. The metalloid aluminum 

is most toxic to aquatic organisms in acidic conditions (i.e., waters with a pH < 7). When 

pH is neutral (7) or higher, aluminum can still inhibit growth of aquatic organisms but to 

a lesser extent. The pH measured in the vessel discharges and ambient water sampled in 

this study was generally 7 or higher. Chronic exposure to high concentrations can cause 

aluminum to accumulate in bones of fish (and humans) and lead to loss of kidney 

function. 

Indications are that the potential risk from total aluminum is greatest in deck washdown 

discharges, followed by fish hold discharges, and then stern tube packing gland 

discharges. For deck washdown, there is an elevated risk because of the high aluminum 

concentrations (possibly from the leaching of the abundant amount of aluminum found on 

the surfaces of many vessels), as well as the potentially large discharge volume (up to 

900 gpd). Fish hold discharge also contains high total aluminum concentrations with 

discharges up to 1,000 gpd. Although concentrations in the stern tube packing gland 

discharge are nearly as high as those in fish hold effluent, potential for risk from stern 

tube packing gland effluent is lower due to the lower volume of the discharge. 

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Chapter 5 - Summary of Findings 

Ambient concentrations of total aluminum were high (ranging from 29 to 3,950 μg/L – 

see Appendix E) in all of the sampled harbors for this study. The average concentration 

of total aluminum in ambient water is higher than the average concentration of total 

aluminum for all discharge types except for deck washdown, fish hold effluent, and stern 

tube/packing gland effluent. For fish hold4

 and stern tube packing gland discharges, it 

appears half of the measured total aluminum likely originates from the ambient water. 

Deck washdown discharge from vessels that use ambient water to clean decks have an 

estimated 20 percent of the measured total aluminum concentrations contributed by 

ambient water. In contrast, only 2 percent of the measured total aluminum concentrations 

were attributable to background concentrations for vessels that used service water to 

clean their decks (primarily tugboats/utility vessels). 

 Concentrations of other metals such as total iron and manganese and dissolved cadmium, 

lead and zinc above their respective screening benchmarks were measured in some 

samples of deck washdown effluents (PHQs ranging from 1 to 11). These heavy metals 

are all known to produce acute and chronic toxic effects in aquatic organisms and 

humans, in the following order: cadmium is more toxic than lead, which is more toxic 

than zinc, which is more toxic than iron. These elevated concentrations were particularly 

prevalent in the deck washdown discharges from utility vessels. However, decks of utility 

vessels (tugboats) are washed less frequently than fishing vessel decks, so overall metal 

loads from the two types of vessels are more comparable than concentrations alone might 

suggest. Although background concentrations of these metals in the ambient and service 

waters used to wash decks were generally low (except for dissolved zinc in some 

background samples), average PHQs of all these metals in vessel discharges were not 

significantly greater than 1, indicating that these metals likely pose minimal potential risk 

to the environment. 

 Total phosphorus concentrations were elevated in some samples of bilgewater, deck 

washdown, fish hold, and graywater discharges. Average PHQs for total phosphorus in 

these discharge categories ranged from a high of 130 in fish hold effluent to a low of 14 

in graywater. Total phosphorus in some vessel discharges comes from detergents and 

soaps. Other total phosphorus loadings come from decaying seafood (in fish hold) or 

leftover food (graywater). Based on concentration and average discharge volume, fish 

hold effluent contributes the most total phosphorus. 

Phosphorus is an important macronutrient limiting reproduction and growth of plant 

material and algae (so called “primary production”). Elevated levels of phosphorus can 

 

4

 The assertion that background concentrations contribute approximately half of aluminum concentrations for fish 

hold effluent assumes that vessels either took in the original fish hold water from the surrounding harbor waters, or 

that the fishing grounds where the vessel took in the fish hold water share similar characteristics with surrounding 

harbor waters. 

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Chapter 5 - Summary of Findings 

contribute to nuisance algal blooms, eutrophication (nutrient enrichment), and low 

dissolved oxygen levels in the water column (hypoxia). Ambient concentrations of total 

phosphorus, averaged across all sampled harbors, were twice the concentration of the 

PHQ screening benchmark. 

 The concentrations of reactive nitrogen compounds (e.g., nitrate, nitrite, ammonia) and 

the parameter TKN were generally not significantly elevated; except for in fish hold and 

fish hold cleaning effluents. Concentrations of ammonia exceed the most stringent 

recommended acute aquatic life criterion. Concentrations of TKN also exceeded the most 

stringent screening value. TKN in fish hold and fish hold cleaning effluent were also 

typical of concentrated raw sewage. 

 Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) were elevated 

in bilgewater, deck washdown, fish hold, and graywater discharges. BOD and COD are 

measures of oxygen-demanding substances present in the discharges (e.g., organic 

matter) that can contribute to hypoxia (low dissolved oxygen) in receiving waters. 

Average BOD concentrations were highest in fish hold effluents (as high as 25 times the 

concentrations in raw sewage), followed by graywater and then bilgewater and deck 

washdown water. The BOD levels in fish hold effluent and graywater are comparable to 

BOD concentrations in raw sewage. Fish hold effluent also has a relatively high 

discharge volume, so this discharge can contribute a significant BOD/COD loading to 

receiving waters, particularly when multiple vessels discharge at the sample location 

(e.g., pierside at a fish processing facility). Hence, depending upon receiving water 

characteristics, BOD and COD from fish hold effluent may significantly impact the local 

environment and contribute to water quality exceedances in receiving waters. 

 Pathogen indicators, E. coli, enterococci, and fecal coliforms, were also found in elevated 

concentrations in some samples of bilgewater and deck washdown (fishing vessels only), 

fish hold, and graywater discharges. These three types of bacteria are all found in animal 

digestive tracts. Epidemiological studies suggest a link between high concentrations of E. 

coli and enterococci in ambient waters and incidents of gastrointestinal illnesses 

associated with swimming. Accordingly, they are used as indicators of the possible 

presence of intestinal pathogens. The highest concentrations by far of all three pathogen 

indicators were found in graywater, with PHQs of around 1,000 for all three bacteria. The 

estimated discharge volume of graywater from study vessels, however, is relatively small 

(130 gpd maximum). Larger vessels with additional crew or passengers are expected to 

generate considerably more graywater (see EPA’s Cruise Ship Discharge Assessment 

Report, USEPA, 2008c). Fish hold effluent contained the second highest concentrations 

of these pathogen indicators and may pose a potential level of risk considering the 

relatively high volume of this discharge and possible discharge by multiple vessels in the 

same location. However, EPA notes that most of the pathogen concentrations in fish hold 

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Chapter 5 - Summary of Findings 

effluent were well below or similar to ambient water concentrations, and this study is 

inconclusive as to whether fish hold effluent results in additional discharge of pathogen 

indicators5

. 

 The semivolatile organic compound bis(2-ethylhexyl) phthalate was found in elevated 

concentrations in some samples of bilgewater, stern tube packing gland, deck washdown, 

firemain, and inboard engine and engine generator discharges. The highest PHQ of 59 for 

bis(2-ethylhexyl) phthalate was found in a bilgewater discharge sample. Even though 

bis(2-ethylhexyl) phthalate was found at elevated concentrations in multiple discharges, 

the overall frequency of detection was low and generally detected at concentrations just 

slightly above the benchmark. This compound is a plasticizer that is added to an everincreasing variety of plastics to provide flexibility and is the most common phthalate in 

the environment. Although no conclusive evidence exists demonstrating bis(2-

ethylhexyl) phthalate affects humans, high concentrations have been shown to feminize 

males of other species. Bis(2-ethylhexyl) phthalate was not analyzed for in fish hold or 

graywater discharge samples. 

 Benzene was the only volatile organic compound found with any frequency at 

concentrations above, but generally close to, the PHQ benchmark. Benzene is a known 

carcinogen that is a common constituent of fuel. Benzene can also be formed as a product 

of incomplete combustion of fuel. Elevated concentrations of benzene were detected in a 

bilgewater sample and in samples from both outboard engine and generator engine 

discharges. 

 Long- or short-chain nonylphenol and octylphenol ethoxylates (two distinct subsets of 

alkylphenol ethoxylates) were detected in some samples of bilgewater, stern tube/packing 

gland, deck washdown, and graywater discharges, and total nonylphenol was detected in 

one sample from bilgewater. Nonylphenols were not analyzed for in samples of the 

remaining discharge types. 

Nonylphenols (a term used generally here to identify a specific group of alkylphenols of 

potential human and environmental concern which also includes the octylphenols) are 

manmade organic compounds that are used in a wide variety of applications, such as the 

manufacturing of detergents, because of their surfactant properties. Nonylphenols are 

synthetic estrogens, which means they can mimic the natural vertebrate hormone estrogen 

 

5

 Fish hold water may also serve as a potential pathway for the spread of aquatic nuisance species (ANS). This might 

occur where fish and water are taken onboard in one place and then transported significant distances for sale or 

unloading and the water is discharged. Organisms discharged with the water may include parasites and commensals 

taken in with fish, as well as organisms taken in with water used for refrigerated seawater. EPA did not study the 

potential for these discharges to transport ANS; however, the Agency is identifying this as a potential area of 

concern that may warrant further research. 

409 

 
Chapter 5 - Summary of Findings 

410 

 

and evoke an estrogen-like response. An example of such a response is the disruption of 

male sexual development, causing female characteristics to emerge. 

Commercial nonylphenol is most accurately described by CAS number 84852-15-3 

(phenol, 4-nonyl-branched), but CAS numbers 104-40-5 (phenol, 4-nonyl-) and 25154-

52-3 (phenol, nonyl) have also been used to describe these compounds. The commercial 

nonylphenol mixtures tested that correspond with EPA’s criteria are those with CAS 

numbers 84852-15-3 and 25154-52-3. The analyte category named “total nonylphenol” in 

the database generated for this study is directly equivalent to the commercial mixture of 

nonylphenol isomers specified under CAS Number 84852-15-3, and thus is directly 

comparable to the NRWQC. 

Total nonlyphenol (or NP) was not detected, except in one bilgewater sample with a PHQ 

of 4. Long-chain nonylphenol and octylphenol ethoxylates were detected with far greater 

frequency, but these longer chain compounds are more water soluble and less toxic than 

NP. The long-chain nonylphenol and octylphenol ethoxylates will all degrade into NP 

over time; however, research is ongoing with regard to proportion and duration of the 

conversion. 

Table 5.1 summarizes the major findings discussed above. 
411 

Table 5.1. Analytes of Potential Risk by Discharge1

Analyte Group 

Discharge Type (Volume/vessel) 

Microbiologicals 

Volatile and 

Semivolatile 

Organic 

Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Classical 

Pollutants 

Nutrients 

Bilgewater (2 to hundreds of gpd; average between 10 and 15 gpd) 

enterococci (detected in only sample collected – shrimping boat; PHQ=124) 

Benzene (Detected in 4 of 7 samples – highest PHQ = 187; towboat) Bis(2-ethylhexyl) phthalate (detected in 4 of 7 samples – non-fishing vessels only; PHQs up to 59) 

Copper (detected in all of 7 samples; PHQ up to 113 - tour boat) Cadmium (detected in only 1 sample; PHQ value of 40 – tour boat). 

Arsenic (detected in all of 7 samples; PHQs 72 to 1,790) 

HEM (detected in all of 7 samples; only one sample where PHQ exceeds factor of 2 – conc. = 44 mg/L; towboat) 

Sulfide(detected in only 2 samples; PHQ as high as 210 from a fishing boat) TRC(highest conc. 0.16 mg/L, tour boat; PHQ = 21) BOD/COD (elevated in 3 of 5 samples; conc. roughly equivalent to raw sewage) 

Total phosphorus (elevated in 3 of 5 samples; highest PHQ=130 – longliner fishing boat) 

Lonshocha(NP singsamshriboa= 4)

Stern tube packing gland effluent (from 4 to 8 gpd) 

NA Bis(2-

ethylhexyl) phthalate (detected in 3 of 9 samples – max. conc. = 24 μg/L; PHQ = 20) 

Nickel(detected in 6 of 9 samples; PHQs in 4 samples from 13 to 126) Copper (detected in 4 of 9 samples; PHQs from 5 to 30) 

Arsenic (detected in 3 of 9 samples; PHQs possibly exceed 250) 

TSS (detected in all of 9 samples – max conc. = 270 mg/L; PHQ = 9) 
412 

Table 5.1. Analytes of Potential Risk by Discharge1

Analyte Group 

Discharge Type (Volume/vessel) 

Microbiologicals 

Volatile and 

Semivolatile 

Organic 

Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Classical 

Pollutants 

Nutrients 

Deck washdown and/or runoff (from 20 to 30 gpd utility; 750 to 900 gpd fishing) 

Fecal coliform, enterococci E. coli

(detected in all 5 samples collected - fishing vessels only. Concentrations of fecal coliform highest in samples; PHQs as high as 40) 

Copper (detected in 29 of 31 samples - PHQs from 2 to 65; highest for utility vessels) Zinc (detected in all of 31 samples – 67% of PHQs between 1 and 10. Max. conc. of 1,200 μg/L in tugboat; PHQ = 14) Lead (detected in 15 of 31 samples – PHQs in 2 samples from 10 to 21) Cadmium (detected in 2 of 31 samples – max. conc. = 22 μg/L in tow boat; PHQ = 90) 

Arsenic(detected in 23 of 31 samples; conc. from 4 to 83 μg/L – PHQs from 200 to 4,000 because very low NRWQC) Aluminum(detected in 30 of 31 samples – PHQs between 7.5 and 150. Max. conc. of 13,000 μg/L in tugboat) Iron (detected in 18 of 19 samples – PHQs between 3.1 and 48. Max. conc. of 14,500 μg/L in tugboat) Manganese (detected only in tugboats and water taxi – PHQs between 1.2 and 13. Max. conc. of 12,800 μg/L in water taxi)2 

HEM 

(detected in 26 of 29 samples – only 3 samples with PHQ > 2. Range of concentrations 1.1 to a max of 133 mg/L in a tugboat) SGT HEM (detected in 22 of 29 samples – only 1 sample with PHQ > 2. Range of concentration 0.91 to a max of 84 mg/L in a tugboat) 

BOD and COD (detected in 29 of 31 BOD samples- all COD samples; concentrations roughly equivalent to raw sewage- all vessel types) TSS (detected in all of 32 samples – PHQs between 1 and 17; max. concentrations in tugboats) TRC (detected in 7 of 31 samples - PHQs between 23 and 100. Max. conc. of 0.8 mg/L in fish trolling boat 

Total phosphorus (detected in all of 31 samples; PHQ as high as 220 in a tugboat) 
413 

Table 5.1. Analytes of Potential Risk by Discharge1

Analyte Group 

Discharge Type (Volume/vessel) 

Microbiologicals 

Volatile and 

Semivolatile 

Organic 

Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Classical 

Pollutants 

Nutrients 

Fish hold/ Fish hold cleaning effluent - Fishing vessels only (tens to several hundred or a few thousand gpd (or gallons per several days dependent upon offloading frequency) based on fishing vessel type and platform) 

Fecal 

coliform, enterococci (detected in only 1 sample well above ambient concentrations; PHQs of 8,900 and 68 respectively) 

 NA Copper

(detected in 23 of 26 samples - PHQs from 1 to 300. Max. conc. of 921 μg/L in shrimper) 

Arsenic (detected in 16 of 26 samples; conc. from 3.1 to 380 μg/L – PHQs from 170 to potentially 21,000 because very low NRWQC) 

BOD and COD (detected in 24 of 26 BOD samples- all COD samples; median concentrations of BOD and COD were 440 and 940 mg/L with max of 5,100 and 8,700 mg/L equivalent to sewage sludge) Sulfide (detected in 7 of 25 samples – PHQs between 5 and 80; max. concentrations = 0.16 mg/L in fish trawler) TSS (detected in all of 26 samples – PHQs of 4 samples between 17 and 37) DO (hypoxic, i.e., ≤ 2.0 

mg/L in 3 of 26 samples – all purse seiners) 

Ammonia (detected in 25 of 26 samples; conc. from 0.087 to 160 μg/L – PHQ at max conc. = 133) TKN (detected in 25 of 26 samples; values indicative of strong sewage) Total phosphorus (detected in 25 of 26 samples - all but 3 samples resulting in PHQs above 10; highest PHQ=760)

NA 
414 

Table 5.1. Analytes of Potential Risk by Discharge1

Analyte Group 

Discharge Type (Volume/vessel) 

Microbiologicals 

Volatile and 

Semivolatile 

Organic 

Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Classical 

Pollutants 

Nutrients 

Graywater (tugs – 130 gpd; taxis – 75 gpd; fishing – a few to few hundred gpd)

E. coli,Fecal coliform, enterococci (detected in 7 of 8 samples collected - concentrations of fecal coliform generally highest in mixed shower/sink samples; PHQs as high as 1,000) 

 NA Copper 

(detected in all of 8 samples - PHQs from 1.7 to 90. Max. conc. of 280 μg/L in tugboat) Zinc (detected in all of 8 samples - max. conc. = 1,500 μg/L in sink water from a water taxi; PHQ = 19) 

HEM 

(detected in all of 8 samples - 4 samples with PHQ 2 or more. Concentrations from 9.4 to a max of 100 mg/L in tugboats) SGT HEM (detected in 6 of 8 samples – only 1 sample with PHQ >2. Range of concentration 1.3 to a max of 35 mg/L from a tugboat) 

Sulfide (detected in 5 of 8 samples – PHQs between 4.8 and 370; max. concentration = 0.73 mg/L in tugboat) BOD and COD (detected in all of 8 samples; median concentration of BOD and COD were 260 and 440 mg/L, respectively with max of 1,200 and 4,000 mg/L indicative of strong sewage) 

Total phosphorus (detected in 8 of 8 samples – all but 3 PHQs above 10; highest PHQ=34 in tugboat) 
415 

Table 5.1. Analytes of Potential Risk by Discharge1

Analyte Group 

Discharge Type (Volume/vessel) 

Microbiologicals 

Volatile and 

Semivolatile 

Organic 

Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Classical 

Pollutants 

Nutrients 

Propulsion Engine Effluent – inboard (20 gpm – high power) 

 NA PAHs 

(6 probable carcinogenic PAHs detected in sample from a recreational vessel with a gasoline engine. Measured concentrations result in PHQs from 2,100 to 4,800) 

Copper (detected in 12 of 13 samples - PHQs from 3 samples from 11 to 17. Max. conc. of 53 μg/L in sample from water taxi at idle) 

Temperature 

(high idle only; temperature increases of up to 20oC) 

NA NA 

Propulsion Engine Effluent – outboard (1 to 2 gpm) 

 NA Benzene 

(detected in 6 of 6 samples – only one sample with a PHQ above 10; value of 28 based on a max. conc. of 62 μg/L in sample from research vessel averaged from variable speeds) 

NA NA
416 

Table 5.1. Analytes of Potential Risk by Discharge1

Analyte Group 

Discharge Type (Volume/vessel) 

Microbiologicals 

Volatile and 

Semivolatile 

Organic 

Compounds 

Metals (dissolved) 

Metals (total) 

Oil and Grease 

Classical 

Pollutants 

Nutrients 

Engine Effluent - Generator (5 to 25 gpm) 

 NA Benzene 

(detected in 3 of 5 samples – only one sample with a PHQ approaching 10; value of 9 based on a max. conc. of 21 μg/L in sample from a fire boat) 

NA NA

Firemain Systems (no volume estimated- used infrequently) 

 NA Copper 

(detected in 4 of 6 samples - PHQs from 3.8 to 23; highest for a tour boat) 

NA NA

Notes: (1) Generally includes analytes when a large proportion of the samples have concentrations exceeding the NRWQC, when several of the samples have P

samples result in PHQs greatly exceeding the screening benchmark (i.e., 100s to 1,000s), or, in the case of oil and grease and for nonylphenol, when one 

existing regulatory limit by more than a factor of 2. See text above and in Section 3.1.3 for a definition of PHQs and Table 3.1 for screening benchmarks u

(2) Longer chain nonylphenol and octylphenol ethoxylates degrade to shorter chained ethoxylates under aerobic conditions. In general, the shorter the chpersistent, and toxic the substance becomes. 4-Nonylphenol (NP) is a shorter-chain nonylphenol that has been found in surface water and is toxic to aquthe longer chain nonylphenol and octylphenol ethoxylates as they break down. The time span from time of use on the vessel to time of sampling of the dis

enough for this to occur, except for discharges of bilgewater. gpm = gallons per minute gpd = gallons per day NA - Not applicable; discharge not analyzed for this analyte group.
5.3 SUMMARY OF PREDICTED IMPACTS FROM SELECT POLLUTANTS IN STUDY 

VESSEL DISCHARGES 

5.3.1 Potential Watershed-Wide Impacts from Study Vessels

Using estimated discharge volumes and average pollutant concentrations, EPA evaluated 

the potential for cumulative effects of the discharges from an assemblage of study vessels on a 

large hypothetical harbor. The evaluation used a screening-level water quality model to estimate 

the pollutant concentration into several hypothetical harbors based on different scenarios of 

vessel groups. Model assumptions included instantaneous and universal dilution of vessel 

discharges in the harbor and a background concentration of zero for all analytes in the harbor 

environment (i.e., the model is not able to evaluate whether vessel discharges are likely to cause 

environmental or human health impacts in the immediate vicinity of the vessel discharges or in 

small water bodies). Instead, the model can only analyze potential vessel loadings to and impacts 

on hypothetical large water bodies. Furthermore, the model is not able to analyze parameters that 

do not have numeric aquatic life or human health based criteria such as BOD or nutrients. 

The model did not predict that discharges from the study vessels solely exceeded aquatic 

life or human health NRWQC for any of the hypothetical harbor scenarios evaluated. This is 

primarily due to the large dilution predicted in these large harbors (even with low flushing). 

However, some of these pollutants from these vessels could reasonably have more significant 

local impacts (although determining this is outside the scope of the model used in this study). In 

smaller water bodies with many vessels or in more confined areas of a harbor with little to no 

flushing, EPA believes study vessel discharges have the potential to cause or contribute to 

exceedances of NRWQC in receiving waters. 

Under the low-dilution scenarios, dissolved copper and total arsenic discharges represent 

the greatest environmental concern and are more likely than other pollutants to contribute to 

exceedances of water quality standards, particularly if there are other sources of these pollutants 

(e.g., stormwater runoff) present. These results are summarized below. 

Dissolved Copper

EPA determined that the loading rates of dissolved copper from a metropolitan harbor 

likely posed the greatest potential risk to human health and aquatic life from study vessels on a 

large scale. Compared to other types of harbors, a metropolitan harbor has a higher level of 

activity from its vessel population and has more support utility vessels such as supply boats, 

tow/salvage vessels, and tugboats. The model predicted that discharges from study vessels have 

the reasonable potential to contribute a significant load of dissolved copper to a water body. 

Furthermore, when considering the loadings of dissolved copper from other sources (e.g., 

recreational vessels, large commercial vessels, stormwater runoff, and industrial and municipal 

417
point sources), the model results suggest a reasonable potential for the concentrations of 

dissolved copper to exceed the NRWQC in this type of harbor. 

The results of this study are consistent with real-world observations that metals are 

frequently associated with vessel discharges in concentrations of potential environmental 

concern. Environmental impacts from dissolved copper leaching from antifouling hull coatings 

have been well documented in low-flushing environments in harbors with large numbers of 

recreational vessels, such as the Shelter Island Yacht Basin near San Diego, California, and 

Marina Del Rey Harbor in Los Angeles, California (see Section 3.3.8.1 of this report). The 

impacts from the high levels of dissolved copper include reduced primary production and 

productivity; accumulation of copper in sediments, reducing sediment quality; and chronic lowlevel toxicity to aquatic organisms, especially sensitive mollusks, crustaceans, and echinoderms.

Total Arsenic

EPA determined that the loading rates of total arsenic (and to a certain extent, dissolved 

arsenic) may pose a potential risk to human health and the environment in low-dilution or lowflushing environments. Arsenic was found to be ubiquitous in this study, both in vessel 

discharges and in ambient water6. Although arsenic concentrations in ambient water can be quite 

high in select harbors, certain discharges from study vessels contribute to the overall arsenic 

load. While the source of total arsenic in vessel discharges is unknown, EPA suspects that 

atmospheric deposition contributes to total arsenic concentrations in deck washdown and 

possibly in bilgewater. Total arsenic in fish hold discharges may be biological in origin (from 

seafood catch) or from sediment entrained in the catch. The biological contribution of arsenic 

may be significant in that total arsenic concentrations are substantially greater in seawater 

organisms than in freshwater organisms (Francesconi and Kuehnelt, 2002; USEPA 2003b). 

The greatest impact of high total arsenic in harbors is primarily via the food chain and 

subsequent bioaccumulation to high levels in seafood consumed by humans. Arsenic exposure 

through drinking water is also of concern where receiving water is used as a source for drinking 

water. Arsenic is strongly linked to cancer in humans and a potent inhibitor of certain enzymes in 

vertebrates. 

5.3.2 Potential Localized or Near-Field Impacts of Vessel Discharges to Receiving 

Waters 

EPA found that some study vessel incidental discharges may pose an environmental 

threat in confined water bodies with low flushing rates and a large population of vessels, in water 

bodies that are hypoxic or hypereutrophic, and/or where the background concentrations or other 

 

6

 See discussion in Section 3.1.3 regarding potential positive interference which may have resulted in elevated 

measured concentrations of arsenic for a subset of samples. 

418
sources of these pollutants are significant. In addition to the parameters (copper and arsenic) 

discussed in Section 5.3.1, the following classical pollutants may likely exhibit near-field effects. 

BOD and COD

In general, oxygen-demanding compounds in vessels discharges (measured as BOD and 

COD) are expected to pose little risk to the environment due to the relatively low volume of 

vessel discharges that contain these pollutants. However, the frequency and magnitude of BOD 

and COD in certain discharges (as much as 25 times the concentrations found in raw sewage) 

warrant additional discussion. 

 Specifically, the relatively high BOD and COD concentrations in fish hold and fish hold 

cleaning effluent could pose a localized water quality impact in areas such as small side 

embayments where flushing rates are low or where portions of the water body are already low in 

dissolved oxygen. The high levels of BOD result from the degradation of organic material and its 

by-products in the fish hold. Higher volume discharges with high BOD concentrations (e.g., 

certain fish hold effluent) may contribute to localized hypoxic conditions in receiving waters, 

depending on the volume of effluent discharged, the number of vessels discharging in confined 

areas, and other factors such as season and water temperature. 

Pathogen Indicators

Bacteria such as E. coli, enterococci, and fecal coliforms are generally of limited concern 

for most discharges where the pathogens were present (i.e., bilgewater, deck washdown, and fish 

hold discharges). However, high levels of pathogens in graywater (and potentially other 

discharge types) may pose some risk to human health and larger vessels with additional crew or 

passengers are expected to generate considerably more graywater than smaller vessels. However, 

looked at on a relative basis, the risk from pathogens in graywater is substantially lower than 

risks from other sources that cause very high concentrations of pathogen indicators in 

surrounding ambient water. For example, during sampling for this study in Massachusetts that 

took place in wet weather, a sanitary sewer overflow and a combined sewer overflow caused 

extremely high pathogen indicator counts in two different harbors, relative to what would be 

expected from graywater discharges from study vessels. 

Total Phosphorus

Nutrients in vessel discharges are generally expected to pose little risk to the 

environment. However, the frequency and magnitude of total phosphorus in certain discharges 

warrants some additional discussion. 

The environmental effects of nutrients are driven by site-specific environmental 

conditions (e.g., receiving water temperature, types of algae present, and limiting nutrient 

conditions). For example, nutrients in vessel discharges may contribute to an environmental 

419
effect in one water body, but not another depending on a variety of environmental conditions that 

control eutrophication (excess productivity in a water body). While EPA has not developed 

NRWQC for total phosphorus and other nutrients in coastal waters, some states have established 

water-body-specific or state-wide standards for nutrients based on site-specific evaluations. 

As mentioned above, the water quality impact of concern for total phosphorus is 

eutrophication. The first indications of potential problems are the increased ambient levels of 

total phosphorus, often followed by an immediate increase in the density (biomass) of the 

planktonic algal community. This increased algal biomass usually blocks light and reduces water 

clarity and may contribute to nuisance algal blooms and declining dissolved oxygen. Of note in 

this study was that the mean total phosphorus concentration in the 15 ambient water samples 

collected was two times the screening benchmark, suggesting that the incremental effect of 

discharges from study vessels may be small. 

5.4 POSSIBLE BENEFITS TO HUMAN HEALTH, WELFARE, AND THE 

ENVIRONMENT FROM REDUCING, ELIMINATING, CONTROLLING, OR 

MITIGATING ONE OR MORE OF THE DISCHARGES FROM THE STUDY 

VESSELS 

Some vessel discharges from commercial fishing vessels and commercial vessels less 

than 79 feet in length may have the potential to impact the aquatic environment and/or human 

health. As noted above, using the results obtained in this study, EPA modeled a hypothetical 

large harbor to evaluate the potential water quality impacts caused by the nine vessel discharge 

types EPA sampled. Based on this evaluation, EPA determined that the incidental discharges 

from study vessels to a relatively large water body are not likely to solely cause an exceedance of 

any NRWQC (i.e., these discharges are unlikely to pose acute or chronic excursions of the 

NRWQC across an entire large water body). However, many of the pollutants in the vessel 

discharges were at end-of-pipe concentrations that exceeded an NRWQC, and therefore have the 

potential to contribute to an exceedance of water quality standards at a more localized scale. The 

study results indicate that total arsenic and dissolved copper are the most significant water 

quality concern for the study vessels as a whole. These pollutants are more likely than other 

pollutants to contribute to exceedances of water quality standards, particularly if there are other 

sources of pollutants or the receiving water already has high background concentrations. 

420
421

.

Gloucester Harbor faces many environmental stressors including Combined Sewer 

Overflows and Urban Stormwater Runoff. For most pollutants, the impact of these sources 

may be more significant than from study vessels. However, some pollutants, such as copper 

or BOD are discharged in notable quantities from certain study vessel discharges. 

Like an individual house in an urban watershed, most individual vessels have only a 

minimal environmental impact. However, the impacts caused by these vessels is potentially 

significant where there are high vessel concentrations, low circulation in waters, additional 

environmental stressors, or pollutant loadings from other sources (e.g., recreational vessels, large 

commercial vessels, stormwater runoff, and industrial and municipal point sources). Reducing 

certain discharges or certain pollutants in discharges from these vessels in sensitive waters may 

result in significant environmental benefits to those waters; however, EPA did not analyze the 

feasibility or cost of managing these discharges as part of this study. 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States 

422 

CHAPTER 6 

ANALYSIS OF THE EXTENT TO WHICH INCIDENTAL 

DISCHARGES ARE CURRENTLY SUBJECT TO REGULATION 

UNDER FEDERAL LAW OR A BINDING INTERNATIONAL 

OBLIGATION OF THE UNITED STATES 

As discussed in Chapter 1, Congress directed EPA, in consultation with the U.S. Coast 

Guard and other interested federal agencies, to conduct a study of discharges incidental to the 

normal operation of all fishing vessels and nonrecreational vessels less than 79 feet in length 

(study vessels). Among other things, the study’s charge directed EPA to include an “analysis of 

the extent to which the discharges are currently subject to regulation under federal law or a 

binding international obligation of the United States” (Public Law (P.L.) 110-299 § 3(b)(6)). 

This chapter and accompanying tables present that analysis. Note, however, that as discussed in 

Chapter 1, this chapter includes some discussion of treaties and statutes that pertain to nonstudy 

vessels for information purposes. In accordance with P.L. 110-299, this study does not include 

significant discussion about discharges of sewage or ballast water.1

 

This chapter is organized into four sections. Section 6.1 offers brief overviews of the 

international obligations addressing vessel discharges, while Section 6.2 summarizes applicable 

federal statutes and regulations. Section 6.3 includes a brief overview of other international and 

federal laws that do not directly regulate discharges incidental to the normal operation of a 

vessel, but which the Agency felt merited some discussion. Finally, Section 6.4 provides tables 

identifying which applicable laws apply to specific incidental discharges. 

6.1 INTERNATIONAL AGREEMENTS

6.1.1 The International Convention for the Prevention of Pollution from Ships (MARPOL

73/78) 

The International Convention for the Prevention of Pollution from Ships, 1973, as 

modified by the Protocol of 1978 (MARPOL 73/78), is the primary international instrument for 

regulating and preventing pollution from vessels. A total of 150 countries are Parties to 

 

1

 As of the writing of this report, ballast water discharges are regulated by the U.S. Coast Guard under the National 

Invasive Species Act of 1996 (NISA), by EPA under Section 402 of the Clean Water Act, and by several states 

under state law. NISA is discussed briefly in this analysis to the extent that it addresses invasive species from 

sources other than ballast water. Furthermore, the International Convention for the Control and Management of 

Ships’ Ballast Water and Sediments (BWM Convention), adopted by the International Maritime Organization (IMO) 

in 2004, establishes ballast water discharge standards. The Convention has not yet attracted the requisite number of 

Parties necessary for its entry into force. For further discussion, see Standards for Living Organisms in Ships’ 

Ballast Water Discharged in U.S. Waters (74 FR 44,631 (Aug. 28, 2009)). 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States 

423 

MARPOL. MARPOL includes six annexes, covering six categories of vessel discharges: oil 

(Annex I), noxious liquid substances (Annex II), harmful packaged substances (Annex III), 

sewage (Annex IV), garbage (Annex V), and air emissions (Annex VI). 

Before entering into force, the Convention required ratification by 15 member states, with 

a combined merchant fleet of not less than 50 percent of the total world shipping fleet, measured 

by gross tonnage. To ratify the convention, member states are required to ratify only Annexes I 

and II; the remaining annexes are optional. The United States has ratified Annexes I, II, III, V, 

and VI (the United States has not ratified Annex IV, which regulates sewage discharges from 

ships; the United States regulates sewage under Section 312 of the Clean Water Act, which is 

discussed in Section 6.2, Federal Laws). 

In the United States, MARPOL is primarily implemented through the Act to Prevent 

Pollution from Ships (APPS), 33 U.S.C. §§ 1901–1915. APPS implements Annexes I, II, V, and 

VI. Annex III of MARPOL is implemented through the Hazardous Materials Transportation Act, 

49 U.S.C. § 5101 et seq. These implementing statutes are discussed in depth in Section 6.2, 

Federal Laws. 

6.1.1.1 MARPOL Annex I: Prevention of Pollution by Oil 

MARPOL Annex I establishes requirements for the control of oil pollution from vessels. 

As previously discussed in this report, small to large amounts of oil can be found in numerous 

vessel discharges, including bilgewater, deck runoff, and engine effluent. The requirements of 

this Annex apply to all ships operating in the marine environment, unless expressly provided 

otherwise. 

Every oil tanker of 150 gt and above and every other ship of 400 gt and above is required 

to undergo a series of surveys to ensure that the ship’s structure, equipment, systems, fittings, 

arrangements, and material are in full compliance with all applicable Annex I requirements and 

do not pose “an unreasonable threat of harm to the marine environment” (Annex I, Regulations 

6.1 and 6.4.1). The surveys are required before the ship is put in service (or before an 

International Oil Pollution Prevention Certificate [IOPP Certificate], explained below, is issued 

for the first time); for IOPP Certificate renewal purposes; at certain intervals surrounding the 

anniversary date of the ship’s IOPP Certificate; and after certain repairs or renewals are 

completed (Annex I, Regulation 6). 

Oil tankers of 150 gt and above and ships of 400 gt and above that travel to ports or 

offshore terminals under the jurisdiction of other Parties to Annex I are required to have an IOPP 

Certificate, which indicates completion of and compliance with Annex I’s inspection 

requirements. These certificates are issued or endorsed by the government of the state, or any 

persons or organizations authorized by it, under whose authority the ship is operating (Annex I, 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States 

424 

Regulation 7). The IOPP Certificate shall not be issued for a time period exceeding five years, 

subject to various survey provisions contained in the Annex (Annex I, Regulation 10). 

Annex I prohibits the discharge of oil or oily mixtures into the sea, except under the 

following circumstances: 

 Ships of 400 gt and above, whether inside or outside a special area where: 

o The ship is proceeding en route. 

o The oily mixture is processed through area-appropriate oil filtering equipment 

(under Regulation 14). 

o The oil content of the effluent without dilution does not exceed 15 parts per 

million (ppm). 

o The oily mixture does not originate from cargo pump-room bilges on oil tankers. 

o The oily mixture, in case of oil tankers, is not mixed with oil cargo residues. 

 Ships of less than 400 gt, whether inside or outside a special area where: 

o The ship is proceeding en route. 

o The ship has in operation equipment of a design approved by the government 

under whose authority the ship is operating, that ensures that the oil content of the 

effluent without dilution does not exceed 15 ppm. 

o The oily mixture does not originate from cargo pump-room bilges on oil tankers. 

o The oily mixture, in the case of oil tankers, is not mixed with oil cargo residues 

(Annex 1, Regulation 15). 

 Discharges of oil or oily mixtures from cargo areas of oil tankers outside special areas 

where: 

o The tanker is more than 50 nautical miles from the nearest land. 

o The tanker is proceeding en route. 

o The instantaneous rate of discharge of oil content does not exceed 30 liters per 

nautical mile. 

o For tankers delivered on or before December 31, 1979, the total quantity of oil 

discharged into the sea does not exceed 1/15,000 of the total quantity of the 

particular cargo of which the residue formed a part, or for tankers delivered after 

December 31, 1979, 1/30,000 of the total quantity of the particular cargo of which 

the residue formed a part. 

o The tanker has in operation an oil discharge monitoring and control system and a 

slop tank arrangement (under Regulations 29 and 31). (Annex 1, Regulation 34). 

Discharges of oil or oily mixtures from the cargo area of an oil tanker while in a special 

area are prohibited (Annex 1, Regulation 34). 

Discharging oil or oily mixtures from any ship in the Antarctic area is expressly 

prohibited. No discharge into the sea may contain substances in quantities or concentrations that 

are hazardous to the marine environment or substances introduced for the purpose of 

circumventing the conditions of discharge specified in Annex 1 (Annex 1, Regulation 15). 
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The prohibition against the discharge of oil and oily mixtures does not apply where the 

discharge is necessary for the purpose of securing the safety of a ship or saving life at sea. The 

prohibition also does not apply where the discharge resulted from damage to the ship or its 

equipment, provided that all reasonable precautions were taken after the occurrence of the 

damage or discovery of the discharge and the damage was not caused intentionally or recklessly 

with knowledge that damage would probably result. Ships may discharge substances containing 

oil when those substances are being used to combat specific pollution incidents in an effort to 

minimize damage from the pollution, subject to relevant governments’ approvals (Annex I, 

Regulation 4). 

Every oil tanker of 150 gt and above and every other ship of 400 gt and above must 

maintain an Oil Record Book Part I.2

 The Oil Record Book Part I must be completed whenever 

any of the following machinery-space events occur: ballasting or cleaning of oil fuel tanks; 

discharge of dirty ballast water or cleaning water from oil fuel tanks; collection and disposal of 

oil residues; discharge overboard or disposal otherwise of bilgewater that has accumulated in 

machinery spaces; bunkering of fuel or bulk lubricating oil; accidental or other exceptional 

discharge of oil; and failure of oil filtering equipment. The Oil Record Book Part I must be 

readily available for inspection. A Party to Annex I may request inspection of the Oil Record 

Book Part I while any ship to which this Annex applies is in its port or offshore terminal and 

require the master of the ship to certify that any copies made of the Oil Record Book Part I are 

true. (Annex I, Regulation 17). 

Oil tankers of 150 gt and above and all other ships of 400 gt and above must carry 

onboard a shipboard oil pollution emergency plan approved by the government under whose 

authority the tanker is operating. The plan must include the procedures for ship operators to 

follow to report an oil pollution incident, the list of authorities or people to be contacted in the 

event of an oil pollution incident, a detailed description of the actions to be taken immediately to 

reduce the discharges of oil following an incident, and a contact onboard responsible for 

coordinating with authorities to combat the pollution. This plan may be combined with the 

emergency response plan required by MARPOL Annex II (discussed below). Oil tankers of 

5,000 tons deadweight or more must have prompt access to computerized damage stability and 

residual structural strength calculation programs (Annex I, Regulation 37). 

Governments of Parties to Annex I must ensure that there are adequate reception facilities 

for discharging oil and oily residues and comply with various requirements related thereto, 

including capacity and location requirements (Annex I, Regulation 38). 

2 Oil tankers must also maintain an Oil Record Book Part II (Annex I, Regulation 36).
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Although ballast water falls outside the scope of P.L. 110-299, the Agency notes that 

Annex I includes regulations governing ballast water. These regulations establish when ships 

must have segregated ballast tanks and under what circumstances ballast water may be carried in 

oil fuel tanks or cargo tanks (Annex I, Regulations 16 and 18). 

In addition to the requirements discussed above, Annex I includes a number of 

requirements applicable to oil tankers alone. Since oil tankers would not generally be expected to 

be study vessels, EPA has omitted an in-depth discussion of these requirements, which include: 

1. New-build protective cargo tank arrangements (including double-hull/double-bottom 

requirements) for certain tankers (Annex I, Regulations 19–20). 

2. Double-bottom pump-room requirements for oil tankers of 5,000 tons deadweight and 

above constructed on or after January 1, 2007 (Annex I, Regulation 22). 

3. Requirement that oil tankers delivered on or after January 1, 2010, be built in such a way 

that if they are damaged, oil will not spill from them at a rate greater than MARPOL 

allows (Annex I, Regulations 23-25). 

4. Limitations on the size and arrangement of cargo tanks for oil tankers of 150 gt and 

above, depending on delivery date (Annex I, Regulation 26). 

5. Subdivision, damage stability, and intact stability criteria (Annex I, Regulations 27–28). 

6. Cargo tank cleaning requirements, including requirements relating to slop tanks (Annex I, 

Regulation 29). 

7. Pumping, piping, and discharge arrangement regulations governing the discharge of dirty 

ballast water or oil-contaminated water (Annex I, Regulation 30). 

8. Oil discharge monitoring and control system requirements, including requirements for 

effective government-approved oil/water interface detectors (Annex I, Regulations 31–

32). 

Also outside the scope of this study, but worth noting, is that Annex I includes 

requirements applicable to fixed or floating platforms. Specifically, fixed or floating platforms 

must comply with the requirements of the Annex applicable to ships of 400 gt and above, other 

than oil tankers, except that they shall be equipped only to the extent practicable relating to tanks 

for oily residue and oil filtering equipment. Records involving oil or oily mixture discharges 

must be kept in a form approved by the government under whose authority the vessel is 

operating, and the discharge of oil or oily mixtures to the sea is prohibited except when the oil 

content of the discharge without dilution does not exceed 15 ppm (Annex I, Regulation 39). 
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6.1.1.2 MARPOL Annex II: Control of Pollution by Noxious Liquid Substances 

in Bulk 

MARPOL Annex II addresses pollution caused by “noxious liquid substances” (NLS) 

carried in bulk. Substances regulated as NLS under MARPOL are categorized into four 

categories3

 based on their potential to cause harm: 

 Category X: Substances that, if discharged into the sea from tank cleaning or 

deballasting operations, present a major hazard to either marine 

resources or human health and therefore justify the prohibition 

of the discharge into the marine environment. 

 Category Y: Substances that, if discharged into the sea from tank cleaning or 

deballasting operations, present a hazard to either marine 

resources or human health or cause harm to amenities or other 

legitimate uses of the sea and therefore justify a limitation on the 

quality and quantity of the discharge into the marine 

environment. 

 Category Z: Substances that, if discharged into the sea from tank cleaning or 

deballasting operations, will present a minor hazard to either 

marine resources or human health and therefore justify less 

stringent restrictions on the quality and quantity of the discharge 

into the marine environment. 

 Other Substances: Substances that fall outside of categories X, Y, or Z because 

they are considered to present no harm to marine resources, 

human health, amenities, or other legitimate uses of the sea 

when discharged into the sea from tank cleaning or deballasting 

operations. The discharge of bilge or ballast water or other 

residues or mixtures containing these substances are not subject 

to any requirements under MARPOL Annex II. (Annex II, 

Regulation 6). 

All ships certified to carry one or more of these substances in bulk must follow the 

requirements established in Annex II unless the discharge is necessary for the purpose of 

securing the safety of a ship or saving life at sea (Annex II, Regulations 2–3). The Annex’s 

requirements also do not apply where the discharge resulted from damage to the ship or its 

equipment, provided that reasonable precautions were taken after the occurrence of the damage 

or discovery of the discharge, and the damage was not caused intentionally or recklessly with 

knowledge that damage would probably result. Discharges of other substances may also be 

exempted from Annex II’s requirements if they are government-approved (by both the 

government under whose authority the ship is operating and any government in whose 

3

 This categorization scheme was developed when Annex II was revised; it entered into force in January 2007. The 

United States Coast Guard’s implementing regulations, discussed below, have not yet been revised to reflect this 

new scheme. 
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jurisdiction the discharge will occur) and being used to combat specific pollution incidents in an 

effort to minimize damage from the pollution (Annex II, Regulation 3). Regulation 4 of Annex II 

provides for a number of other specific exemptions to the Annex’s requirements. 

Ships intending to carry NLS in bulk to other Parties to MARPOL must obtain an 

International Pollution Prevention Certificate for the Carriage of Noxious Liquid Substances in 

Bulk (“Certificate”). The Certificate records the results of the various inspections to which NLScarrying ships are subject. The government under which the ship is registered is typically 

responsible for issuing the Certificate, using a form provided in Appendix 3 to Annex II (Annex 

II, Regulation 9). Certificates are issued for a period of time not to exceed five years (Annex II, 

Regulation 10). 

Prior to and at periodic intervals after a ship is issued a Certificate, it is subject to a 

complete inspection of its structure, equipment, systems, fittings, arrangements, and materials to 

ensure compliance with Annex II. The government of the country under whose authority a ship is 

operating is responsible for having these inspections conducted. If a ship or its equipment is 

found to not correspond substantially with the particulars of the Certificate, corrective action 

must be taken. If corrective action is not taken, the ship’s Certificate should be withdrawn. 

Conformity with these MARPOL requirements is necessary to ensure that the ship does not pose 

an unreasonable threat of harm to the marine environment (Annex II, Regulation 8). 

Ships that are certified to carry NLS in bulk that are identified in chapter 17 of the 

International Bulk Chemical Code must generally ensure that their design, construction, 

equipment, and operation are in conformance with the requirements of that Code (Annex II, 

Regulation 11). 

Ships constructed prior to July 1, 1986, must have a pumping and piping arrangement 

ensuring that each tank certified to carry substances in Category X or Y does not retain more 

than 300 liters of residue in the tank and its associated piping. Each tank certified to carry 

substances in Category Z must not retain more than 900 liters in the tank and its associated 

piping (Annex II, Regulation 12(1)). Ships constructed on or after July 1, 1986, but before 

January 1, 2007, must not retain residue greater than 100 liters for Category X or Y substances or 

300 liters for Category Z substances in the tank and its associated piping (Annex II, Regulation 

12(2)). Ships constructed after January 1, 2007, must not retain residue in a quantity greater than 

75 liters in the tank or its associated piping for Category X, Y, or Z (Annex II, Regulation 12(3)). 

Ships certified to carry Category X, Y, or Z substances, except ships constructed before 

January 1, 2007, and certified to carry Category Z substances, must have at least one underwater 

discharge outlet, which must be located within the cargo area in the vicinity of the turn of the 

bilge and arranged to avoid the re-intake of residue/water mixtures by the ship’s seawater 

intakes. The residue/water mixture discharged into the sea must not pass through the ship’s 

boundary layer (Annex II, Regulation 12 (6)-(9)). 
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Ships are prohibited from discharging into the sea residues of Category X, Y, or Z 

substances or ballast water, tank washings, or other mixtures containing these substances unless 

the discharges fully comply with the applicable operational requirements of Annex II. 

Specifically, 1) the ship must be proceeding en route at a speed of at least 7 knots in the case of 

self-propelled ships or at least 4 knots for other ships, 2) the discharge must be made below the 

waterline through the underwater discharge outlets at a rate not to exceed what the outlet was 

designed for, and 3) the discharge must be made no less than 12 nautical miles from the nearest 

land and in water not less that 25 meters deep (Annex II, Regulation 13(1)-(2)). For Category Z 

substances on ships not required to have an underwater discharge outlet, the requirement that 

discharges occur below the waterline does not apply. Annex II also sets out requirements for the 

discharge of NLS residues (Annex II, Regulation 13(6)–(7)). Any discharge of NLS or mixtures 

into the Antarctic area is prohibited (Annex II, Regulation 13(8)). 

Every ship certified to carry Category X, Y, or Z substances must have a government 

approved Manual onboard. The Manual is meant to inform the ship’s officers of the physical 

arrangements and operational procedures necessary to comply with Annex II (Annex II, 

Regulation 14). Ships must also carry with them a Cargo Record Book to record where NLS 

substances were loaded and unloaded and the circumstances of the loading and unloading. If any 

accidental or emergency discharges occur, those must also be recorded in the Cargo Record 

Book (Annex II, Regulation 15). 

Ships certified to carry NLS in bulk that weigh 150 gt or above must carry onboard a 

marine pollution emergency plan for NLS. The plan must be government approved and must 

include the procedures for ship operators to follow to report an NLS pollution incident, the list of 

authorities and people to be contacted in the event of an NLS pollution incident, a detailed 

description of the actions to be taken immediately to reduce the discharges of NLS following an 

incident, and a contact onboard responsible for coordinating with authorities to combat the 

pollution (Annex II, Regulation 17). 

The Government of each Party to MARPOL must ensure that its ports and terminals have 

adequate NLS reception facilities for the ships utilizing those ports and terminals to meet the 

requirements of Annex II (Annex II, Regulation 18). 

6.1.1.3 MARPOL Annex III: Prevention of Pollution by Harmful Substances 

Carried by Sea in Packaged Form 

MARPOL Annex III establishes requirements for preventing pollution caused by harmful 

substances that are carried in packaged form. “Harmful substances” are defined as those 

substances that are identified as marine pollutants in the International Maritime Dangerous 

Goods Code (IMDG Code). “Packaged form” is defined as the forms of containment specified 

for harmful substances in the IMDG Code (Annex III, Regulation 1(1)). Although the 

requirements of this Annex do not directly regulate discharges incidental to the normal operation 
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of a vessel, they play a critical role in preventing harmful substances from entering into such 

discharge streams. 

Annex III prohibits the carriage of harmful substances from all ships unless the 

requirements of the Annex are followed (Annex III, Regulation 1(2)). Empty packages that were 

previously used to carry harmful substances and contain harmful residue are themselves 

considered harmful substances and must be treated as such (Annex III, Regulation 1(4)). 

Additionally, the Government of each Party to MARPOL is required to issue detailed 

requirements on packing, marking, labeling, documentation, stowage, quantity limitations, and 

exceptions for preventing or minimizing pollution of the marine environment by harmful 

substances (Annex III, Regulation 1(3)). 

The Annex requires that packages containing harmful substances be adequate to 

minimize the hazard to the marine environment, having regard to their specific contents (Annex 

III, Regulation 2). They must be durably marked with the correct technical name (trade names 

alone are prohibited), must indicate that the substance is a marine pollutant, and should be 

supplemented where possible by other means (e.g., use of the relevant United Nations number). 

The durability of both the package and the markings must be considered because the Annex 

requires that the markings be able to withstand at least three months immersed in the sea (Annex 

III, Regulation 3). 

In all documents relating to the carriage of harmful substances at sea, the correct 

technical name of each substance must be used, and the substance must be identified with the 

words “MARINE POLLUTANT.” The shipping documents provided by the shipper must be 

accompanied by a signed certificate declaring that the shipment is properly packaged and marked 

and in proper condition for carriage to minimize the hazard to the marine environment. Every 

ship must keep, both onboard and onshore, a list or manifest detailing the harmful substances 

onboard and where they are stowed (Annex III, Regulation 4). 

Packages containing harmful substances must be stowed and secured so as to minimize 

the hazards to the marine environment, without impairing the safety of the ship and the people 

onboard (Annex III, Regulation 5). Some harmful substances may face restrictions, for sound 

scientific and technical reasons, as to the quantity that can be carried onboard, and in some cases, 

carrying them might be prohibited altogether. These determinations will take into account the 

size, construction, and equipment of the ship, as well as the packaging and nature of the 

substance (Annex III, Regulation 6). 

Except where necessary to protect the ship or saving life at sea, the jettisoning of harmful 

substances carried in packaged form is prohibited (Annex III, Regulation 7). 
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6.1.1.4 MARPOL Annex IV: Prevention of Pollution by Sewage from Ships 

Annex IV of MARPOL establishes requirements for the prevention of pollution caused 

by sewage from ships. The discussion of discharges of sewage from vessels was specifically 

excluded from the scope of this study; therefore, the summary of this section is omitted. See P.L. 

110–299, § 3(c)(2). It should also be noted that, as mentioned above, the United States is not a 

party to Annex IV and is therefore not obligated to follow its requirements. 

6.1.1.5 MARPOL Annex V: Prevention of Pollution by Garbage from Ships 

Annex V of MARPOL regulates garbage pollution from ships. Under the Annex, 

“Garbage” is defined as all kinds of victual, domestic, and operational waste (excluding fresh 

fish and fish parts) generated during the normal operation of the ship and liable to be disposed of 

continuously or periodically (Annex V, Regulation 1(1)). Although the requirements of this 

Annex do not directly regulate discharges subject to this report (“garbage” is not subject to the 

former NPDES permit exclusion at 40 CFR 122.3(a)), they play a critical role in preventing 

garbage from entering into and contaminating discharge streams subject to this report. 

The Annex establishes different disposal requirements depending on the type of garbage 

being disposed of. Disposal into the sea of dunnage—lining and packing materials that will 

float—is prohibited if the ship is closer than 25 nautical miles from the nearest land. The 

disposal of food wastes and all other garbage, including paper products, rags, glass, metal, 

bottles, crockery, and similar refuse is prohibited less than 12 nautical miles from the nearest 

land; however, it may be permitted if it has passed through a comminuter or grinder, is small 

enough that it can pass through a screen with openings no greater than 25 mm, and is disposed of 

as far as practicable from the nearest land (but no closer than 3 nautical miles). The disposal of 

plastics, including but not limited to synthetic ropes, synthetic fishing nets, and plastic garbage 

bags, is prohibited. Where garbage is mixed, the more stringent requirements will apply (Annex 

V, Regulation 3). Additional special requirements are in place for discharges into certain defined 

areas.4

 

None of the disposal regulations described above apply where: 1) the disposal was 

necessary for the purpose of securing the safety of the ship or those onboard or saving life at sea; 

2) the garbage escaped as the result of damage to the ship (provided all reasonable precautions 

were taken before and after the incident to prevent or minimize the escape); or 3) disposal was 

the result of an accidental loss of synthetic fishing nets (provided that all reasonable precautions 

were taken to prevent the loss) (Annex V, Regulation 6). 

4

 For the purposes of Annex V, the special areas are the Mediterranean Sea area; the Baltic Sea area; the Black Sea 

area; the Red Sea area; the “Gulfs” area; the North Sea area: the Antarctic area; and the wider Caribbean region, 

including the Gulf of Mexico and the Caribbean Sea (although the rules have not entered into force with respect to 

all of these areas yet). For the specific requirements, see Annex V, Regulation 5. 
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The Parties to the Annex must ensure that ports and terminals have adequate facilities for 

the reception of garbage (Annex V, Regulation 7). 

Each ship 12 meters or more in length must display placards that notify those onboard of 

the various disposal requirements. The placards must be written in the working language of the 

ship’s personnel and, for ships engaged in voyages to ports or offshore terminals under the 

jurisdiction of other Parties to the Convention, shall also be in English, French, or Spanish 

(Annex V, Regulation 9(1)). 

Every ship 400 gt and above and every ship certified to carry 15 or more people must 

carry a garbage management plan for the crew to follow. The plan must describe procedures for 

collecting, storing, processing, and disposing of garbage, including the use of equipment 

onboard. It must be written in the working language of the crew and identify the person in charge 

of carrying out the plan (Annex V, Regulation 9(2)). Ships of this size or certification that travel 

to ports or offshore terminals under the jurisdiction of other countries party to MARPOL, and 

every fixed and floating platform engaged in exploration and exploitation of the seabed, must 

also carry a Garbage Record Book onboard. The Garbage Record Book must include a record of 

every discharge operation or incineration, including the date and time of the discharge, the 

position of the ship, a description of the garbage, and the estimated amount discharged or 

incinerated. Any escapes or accidental losses must also be noted in the Garbage Record Book, 

along with a description of the circumstances of the loss (Annex V, Regulation 9(3)). 

6.1.1.6 MARPOL Annex VI: Prevention of Air Pollution from Ships 

Annex VI of MARPOL regulates air emissions from ships. Air emissions are outside the 

scope of this study, therefore, the summary of this Annex has been omitted. 

6.1.1.7 MARPOL Summary 

The earlier chapters of this study describe a number of pollutants detected by EPA in 

incidental vessel discharges that have the potential to pose a risk to human health or the 

environment. Of these pollutants of concern, it appears that oil and grease are the only pollutants 

found in incidental discharges that would be directly regulated by MARPOL, through Annex I. 

However, MARPOL may indirectly regulate other pollutants found in incidental discharges, such 

as metals, to the extent that they are found in any of the noxious liquid substances categorized 

under Annex II or garbage under Annex V and prevented from entering incidental discharge 

streams . In all cases, the requirements of MARPOL only apply to those vessels that are large 

enough to meet the size thresholds established in the treaty. 

6.1.2 The International Convention on the Control of Harmful Anti-Fouling Systems on 

Ships

The International Convention on the Control of Harmful Anti-Fouling Systems on Ships 

was adopted by the IMO on October 5, 2001, and entered into force on September 17, 2008. The 
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U.S. Senate gave its consent to ratify the Convention on September 26, 2008; however, the 

United States will not deposit its instrument of ratification with the IMO until Congress adopts 

the necessary implementing legislation. Implementing legislation was introduced on September, 

24, 2009. See Clean Hull Act of 2009, H.R. 3618, 111th Congress (1st Session 2009). If passed, 

this new legislation would replace the Organotin Anti-Fouling Paint Control Act of 1988 

(OAPC), discussed below. 

Parties to the Convention are required to take steps to reduce or eliminate adverse effects 

on the marine environment and human health caused by antifouling systems. Under the 

Convention, an “antifouling system” is any coating, paint, surface treatment, surface, or device 

used on a ship to control or prevent the attachment of unwanted organisms (Article 2(2)). 

The Convention applies to any ship entitled to fly the flag of a Party; ships not entitled to 

fly the flag of a Party but that operate under the authority of that Party; and ships that enter a 

port, shipyard, or offshore terminal of a Party but do not fall under one of the earlier categories. 

Warships, naval auxiliary, or other ships owned or operated by a Party are exempted when used 

only for noncommercial government service. However, each Party must ensure that these 

exempted ships operate in a manner consistent with the Convention, where reasonable and 

practicable. Parties must also ensure that favorable treatment is not given to ships registered to 

countries that are not Parties to the Convention (Article 3). 

Under the Convention, Parties must prohibit and/or restrict the application, reapplication, installation, or use of environmentally harmful antifouling systems on ships 

registered under them, as well as on ships that enter its ports, shipyards, or offshore terminals 

(Article 4). As of January 1, 2008, ships are prohibited from having any organotin compounds on 

their hulls that act as biocides, unless the compounds have been sealed so that no leaching occurs 

(Annex I). 

Parties to the Convention must take measures to require that wastes generated by the 

application or removal of an antifouling system are collected, handled, treated, and disposed of 

in a safe and environmentally sound manner (Article 5). In the United States., this provision 

would be implemented through the Solid Waste Disposal Act, 33 U.S.C. §§ 6901–6992, and the 

Clean Water Act, 33 U.S.C. §§ 1251–1387. 

Any Party can propose an amendment to the Convention, including proposals to prohibit 

antifouling systems other than organotins. The process for proposing an amendment, and 

subsequently considering and adopting it, is described in Articles 6, 7, and 16. 

Parties must take appropriate measures to promote and facilitate scientific and technical 

research on the effects of antifouling systems, as well as monitoring these effects. The research 

should include observation, measurement, sampling, evaluation, and analysis of the effects of 
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antifouling systems. Parties should share the information learned in these studies with other 

Parties to the Convention when requested (Article 8). 

The Convention requires Parties to report to the IMO a list of all surveyors and 

organizations that are authorized to act on behalf of that Party in administration of matters 

relating to the control of anti-fouling systems. Parties must also annually report information 

regarding any antifouling systems that were approved, restricted, or prohibited under domestic 

law. For antifouling systems that were approved, registered, or licensed by a Party, that Party 

must provide to other Parties upon request relevant information on which that decision was made 

(alternatively, a Party could require the manufacturers of approved, registered, or licensed 

antifouling systems to provide this information) (Article 9). 

A Party must ensure that ships entitled to fly under its flag or operate under its authority 

are surveyed and certified in accordance with the requirements of Annex 4 (Article 10). Annex 4 

requires that ships of 400 gt and above that are engaged in international voyages be surveyed 

before the ship is put into service and whenever the antifouling systems are changed or replaced. 

The survey is intended to ensure the ship’s antifouling system fully complies with the 

Convention (Annex 4, Regulation 1). At the conclusion of the survey, the ship will be issued an 

International Anti-Fouling System Certificate (Annex 4, Regulation 2). Ships less than 400 gt 

and 24 meters or more in length and that are engaged in international voyages must carry a 

Declaration, signed by the owner or his agent, declaring that the antifouling system used on the 

ship complies with the requirements of the Convention (Annex 4, Regulation 5). 

Ships to which the Convention applies may be inspected in any port, shipyard, or 

offshore terminal of a Party. Unless there are clear grounds for believing that a ship is in 

violation of the Convention, the inspection is limited to: 1) verifying that, where required, there 

is a valid International Anti-Fouling System Certificate or Declaration onboard; and/or 2) a brief 

sampling of the ship’s antifouling system, taking into account IMO guidelines. If there are clear 

grounds to believe that a ship is in violation of the Convention, a more thorough inspection is 

permitted, taking into account IMO guidelines. Additionally, a Party may take steps to warn, 

detain, dismiss, or exclude from its ports any ship that is found to be in violation but must 

immediately notify the country under whose flag the ship is registered (Article 11). 

Parties must, through domestic laws, prohibit violations of the Convention and establish 

sanctions severe enough to discourage violations.5

 If a violation occurs within the jurisdiction of 

a Party, that Party must either cause proceedings to be taken in accordance with its domestic 

laws or furnish any information or evidence it has showing a violation has occurred to the 

government under whose authority the ship concerned is operating. If that government finds the 

5

 For vessels larger than 79 feet, EPA has prohibited the discharge of tributyltin and other organotins under the 

Agency’s Vessel General Permit (see Section 6.2.3). 
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evidence sufficient to enable proceedings to be brought, it must do so as soon as possible, in 

accordance with its laws, and notify both the IMO and the reporting Party that it has done so. If 

the government does not take action within one year after receiving the information, it must so 

inform the Party that reported the alleged violation (Article 12). 

Parties must make every effort to avoid unduly detaining or delaying ships while 

conducting inspections or investigating potential violations. If a ship is unduly detained or 

delayed, it is entitled to compensation for any loss or damage suffered (Article 13). 

The Convention does not prejudice the rights or obligations of any country under 

customary international law as reflected in the United Nations Convention on the Law of the Sea 

(Article 15). 

Presently, the International Convention on the Control of Harmful Anti-Fouling Systems 

on Ships only regulates the use of organotin tributyling (TBT) in antifouling coatings. Effective 

January 2003, new applications of antifouling coatings containing TBT were prohibited by the 

treaty, and as of January 2008, all vessels with an existing TBT antifouling coating on their hulls 

are required to apply a protective coating over the TBT to prevent leaching. 

Since the use of TBT has been prohibited, vessel operators have turned to anti-fouling 

systems that contain other potentially harmful pollutants, such as copper. Copper is not currently 

regulated under the International Convention on the Control of Harmful Anti-Fouling Systems 

on Ships; however, the treaty provides a system whereby Parties may propose that a specific 

anti-fouling system be regulated under the treaty. Through this mechanism, copper may one day 

be regulated under the treaty if parties to the treaty determine it is necessary. 

6.1.3 International Convention for the Safety of Life at Sea (SOLAS)

The International Convention for the Safety of Life at Sea (SOLAS) is considered the 

most important international treaty concerning the safety of merchant ships. The first version was 

adopted in 1914 in response to the Titantic disaster and has been amended many times since 

then, most recently in 1974. The primary objective of SOLAS is to establish minimum standards 

for the construction, equipment, and operation of ships, in consideration of their safety. The 

responsibility for ensuring compliance rests with the individual flag states, although contracting 

governments do have limited authority to inspect ships of other contracting governments if there 

are clear grounds for believing the SOLAS requirements are not being met. For additional 

information on SOLAS, please see the IMO’s discussion of the Convention at www.imo.org 

While SOLAS does not directly regulate vessel discharges, it does provide environmental 

benefits through its regulations and through adoption of the International Safety Management 

(ISM) Code, all of which assist in preventing spills and other accidental discharges. The ISM 

Code provides an international standard for safely managing and operating ships and for 
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preventing pollution. In addition to other requirements, under the Code, companies or individuals 

responsible for operating vessels must establish a safety and environmental-protection policy and 

ensure that the policy is implemented and maintained at all levels of the organization, both shipbased and shore-based. These operators must also create a safety management system, which is a 

structured and documented system that enables company personnel to effectively implement the 

company’s safety and environmental protection policy (ISM Code, Part A). 

SOLAS could be used to address any of the pollutants of potential concern identified by 

EPA though this study, to the extent that the individual policies adopted by vessel operators 

address specific pollutants found in incidental discharges. 

6.1.4 Boundary Waters Treaty

The Boundary Waters Treaty is an agreement the United States and Canada entered into 

in 1919 to govern the management of boundary waters. Among other things, the treaty provides 

that “boundary waters” – defined as “waters from main shore to main shore of the lakes and 

rivers and connecting waterways, or the portion thereof, along with the international boundary” 

between the U.S. and Canada - “and waters flowing across the boundary shall not be polluted on 

either side to the injury of health or property on the other” (Preliminary Article and Article IV.2). 

The Treaty established the International Joint Commission (IJC), composed of three 

commissioners from each country, to assist in the resolution of boundary water issues (Article 

III). Since 1919, the IJC has addressed a variety of water-use and water-quality issues. The 

Treaty is a foundational backdrop for other bilateral agreements between the United States and 

Canada, such as the Great Lakes Water Quality Agreement. 

As a foundational agreement, the Boundary Waters Treaty does not directly regulate 

specific pollutants, which means it does not directly regulate specific pollutants in incidental 

discharges. 

6.1.5 Great Lakes Water Quality Agreement

The Great Lakes Water Quality Agreement, first signed in 1972, and revised in 1978 and 

1987, expresses the commitment of both the United States and Canada to restore and maintain 

the chemical, physical, and biological integrity of the waters of Great Lakes Basin Ecosystem. It 

also reaffirms the rights and obligations of both countries under the Boundary Waters Treaty. 

The Great Lakes Water Quality Agreement is primarily implemented through Section 118 of the 

Clean Water Act. 

One of the stated policies in the Agreement is the prohibition of discharges of toxic 

substances in toxic amounts and the virtual elimination of discharges containing any or all 

persistent toxic substances (Article II). The general objectives of the agreement are to ensure that 

the waters in the Great Lakes System are free from pollutants resulting from human activity, 
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such as substances that will settle to form sludge deposits or harm aquatic life or waterfowl; 

floating materials (e.g., debris, oil, scum, other immiscible substances); materials or heat that 

produce color, odor, taste, or other conditions that will interfere with beneficial uses or are toxic 

or harmful to human health or the environment; and nutrients that create growths of aquatic life 

that interfere with beneficial uses (Article III). 

Vessel discharges are directly addressed through Annexes 4 (discharges of oil and 

hazardous polluting substances from vessels), 5 (discharges of vessel wastes), and 6 (review of 

pollution from shipping sources) of the Agreement. In all of these annexes, “vessel” is defined as 

“any ship, barge or other floating craft, whether or not self-propelled” (Annex 4(1)(e), Annex 

5(1)(e)). 

Annex 4 addresses discharges of oil and hazardous polluting substances from vessels. 

Within this annex, the term “discharge” includes, but is not limited to, any spilling, leaking, 

pumping, pouring, emitting, or dumping; it does not include unavoidable direct discharges of oil 

from a properly functioning vessel engine (Annex 4(1)(a)). The annex requires that each country 

adopt regulations to prevent discharges of harmful quantities of oil and hazardous substances 

from vessels into the Great Lakes System. Specifically: 

 Discharges of harmful quantities of oil or hazardous substances, including those 

contained in ballast water, must be prohibited and made subject to appropriate 

penalties. 

 As soon as any person in charge, including a vessel owner/operator, becomes aware 

of a discharge, or probable discharge, of harmful quantities of oil or hazardous 

substances, he/she must immediately notify the appropriate agency in the 

jurisdiction where the discharge occurred. Failure to give this notice must be subject 

to appropriate penalties (Annex 4(2)). 

A “harmful quantity of oil” is defined as “any quantity of oil that, if discharged from a 

ship that is stationary into clear calm water on a clear day, would produce a film or a sheen upon, 

or discoloration of, the surface of the water or adjoining shoreline, or would cause a sludge or 

emission to be deposited beneath the surface of the water or upon the adjoining shoreline” 

(Annex 4(1)). 

Annex 4 also requires both countries to adopt regulations for the design, construction, 

and operation of vessels, as well as programs to ensure that merchant vessel personnel are trained 

in the use, handling, and stowage of oil and abatement of oil pollution, thereby preventing the 

discharge of harmful quantities of oil or hazardous polluting substances. For oil, the regulations 

must ensure that each vessel has a suitable means for containing spills of oil and oily wastes and 

retaining those wastes onboard for off-load at a reception facility. Oil loading, unloading, and 

bunkering systems must be suitably designed to minimize the possibility of failure (Annex 4(3)). 
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For hazardous polluting substances, each country must adopt programs and measures to 

prevent discharges of harmful quantities of hazardous polluting substances carried as cargo. Such 

regulations include ensuring that all vessels have a suitable means of containing onboard spills 

caused by loading or unloading operations and have the capability of retaining onboard wastes 

accumulated during vessel operation for off-loading to a reception facility. The regulations must 

also provide for the identification of vessels carrying cargos of hazardous substances and for the 

identification in vessel manifests of all the hazardous substances those vessels are carrying 

(Annex 4(4)). A list of hazardous polluting substances and potential hazardous polluting 

substances can be found in Appendices 1 and 2 to Annex 10. 

Additionally, under Annex 4, both countries must ensure that there are adequate facilities 

for the reception, treatment, and subsequent disposal of oil and hazardous polluting substances 

from all vessels (Annex 4(5)). 

Annex 5 addresses discharges of vessel wastes, including garbage, sewage, and waste 

water. “Garbage” is defined as “all kinds of victual, domestic, and operational wastes, excluding 

fresh fish and parts thereof generated during the normal operation of the ship and liable to be 

disposed of continually or periodically.” “Wastewater” encompasses any water combined with 

other substances, “including ballast water and water used for washing cargo hold, but excluding 

water in combination with oil, hazardous polluting substances, or sewage” (Annex 5(1)). 

The agreement requires both countries to adopt regulations that will: 

 Prohibit the discharge of garbage from vessels and make such discharges subject to 

appropriate penalties. 

 Prohibit the discharge of wastewater in harmful amounts or concentrations and make 

such discharges subject to appropriate penalties. 

 Ensure that each vessel operating in boundary waters, and that has toilet facilities, is 

equipped with a device to contain, incinerate, or treat sewage to an adequate degree. 

Appropriate penalties must be provided for failure to comply (Annex 5(2)). 

Within the Great Lakes System, certain critical use areas may be designated where the 

discharge of wastewater or sewage will be limited or prohibited (Annex 5(3)). Both countries 

must take measures to ensure there are adequate facilities for the reception, treatment, and 

subsequent disposal of garbage, wastewater, and sewage from vessels (Annex 5(5)). 

Annex 6 calls on both the Canadian and U.S. Coast Guards to review “services, systems, 

programs, recommendations, standards, and regulations relating to shipping activities for the 

purpose of maintaining or improving Great Lakes water quality” (Annex 6(1)). The two Coast 

Guards must meet at least annually to consult on implementing the Agreement (Annex 6(2)). 

Of the pollutants of potential concern identified by EPA earlier in this study, oil and 

grease are the pollutants most directly addressed under the Great Lakes Water Quality 
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Agreement. The Agreement also addresses wastewater, which may include some incidental 

discharges. Under the Clean Water Act, the Great Lakes National Program Office is tasked with 

developing and implementing specific action plans to carry out the responsibilities of the U.S. 

under the Great Lakes Water Quality Agreement. (33 U.S.C. § 1268(c)(1)(A)). EPA might be 

able to address incidental discharges through these action plans to the extent those discharges are 

“wastewater” as that term is defined in the Agreement. 

Annex I lists a number of chemicals and pollutants that are specific objectives of the agreement, 

including metals such as arsenic, cadmium, chromium, copper, and nickel, among others. Annex 

I also provides standards for the concentration of total dissolved solids, hydrogen sulfide, 

phosphorus, and other pollutants in the Great Lakes. 

6.1.6 St. Lawrence Seaway Regulations

In 1954, the United States statutorily created the Saint Lawrence Seaway Development 

Corporation to construct, operate, and maintain the section of the St. Lawrence Seaway between 

the Port of Montreal and Lake Erie that falls within the territorial limits of the United States (33 

U.S.C. § 981). The mission of the wholly government-owned corporation, which is under the 

direction and supervision of the Department of Transportation, is to improve the operation and 

maintenance of a deep-draft waterway in cooperation with a Canadian counterpart.6

 

The Department of Transportation’s regulations governing the Seaway can be found at 33 

CFR Part 401. The regulations define the St. Lawrence Seaway as the “the deep waterway 

between the Port of Montreal and Lake Erie and includ[ing] all locks, canals and connecting and 

contiguous waters that are part of the deep waterway, and all other canals and works, wherever 

located, the management, administration and control of which have been entrusted to the 

Corporation or the Manager” (33 CFR § 401.2(j)). 

While the regulations are primarily geared toward maintaining and using the Seaway, 

they do include provisions designed to lessen the impacts of vessel pollution to the Great Lakes, 

including a provision that prohibits the discharge of garbage, ashes, ordure, litter, or other 

materials into the Seaway (33 CFR § 401.59(d)). The regulations also prohibit any vessel from 

emitting sparks or excessive smoke, or from blowing boiler tubes (33 CFR § 401.59(a)). In 

addition, the regulations contain a blanket requirement that no discharge is allowed that is not in 

 

6

 In addition to the authorities under its enabling statute, 33 U.S.C. § 981 et seq., the St. Lawrence Seaway 

Development Corporation has authority to “operate, maintain, improve or expand vessel traffic services consisting 

of measures for controlling or supervising vessel traffic or for protecting navigation and the marine environment” 

pursuant to the Ports and Waterways Safety Act of 1978, at 33 U.S.C. 1223–1225, 1229. The U.S. Coast Guard has 

this authority in all other navigable waters of the United States, except for the area under the jurisdiction of the 

Corporation.
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conformity with all applicable U.S. and Canadian regulations, except within certain areas of the 

Welland Canal, where no discharges are allowed at all (33 CFR § 401.59(b)). 

Although ballast water is not a focus of this study, it should be noted that the St. 

Lawrence Seawater Regulations also include provisions relating to ballast water, including a 

recently passed regulation requiring all oceangoing vessels entering the Seaway to conduct 

saltwater flushing (Seaway Regulations and Rules: Periodic Update, Various Categories, 73 FR 

9950 (February 25, 2008)). 

The St. Lawrence Seaway Regulations only regulate specific pollutants to the extent they 

are found in ballast water. 

6.2 FEDERAL LAWS

6.2.1 Act to Prevent Pollution from Ships (APPS)

The Act to Prevent Pollution from Ships (APPS) is the United States law implementing 

Annexes I, II, V, and VI of MARPOL (Annex III is implemented through the Hazardous 

Materials Transportation Act). The U.S. Coast Guard has the primary authority to implement and 

enforce the majority of provisions within APPS. EPA was also given specific authorities in 

certain sections of APPS, the most extensive of which relate to MARPOL Annex VI. The Coast 

Guard’s implementing regulations, found at 33 CFR Part 151, are addressed below. 

APPS applies to U.S.-registered ships regardless of where in the world they are operating. 

With respect to the implementation of Annexes I and II, APPS additionally applies to all foreignflagged ships operating in navigable U.S. waters. The implementation of Annex V applies to all 

U.S.-registered ships, as well as all foreign-flagged ships in navigable U.S. waters or the 

exclusive economic zone of the United States (33 U.S.C. § 1902(a)). Warship, naval auxiliary, 

and ships owned by the United States that are engaged in noncommercial service are exempted 

from the requirements of APPS, except for certain provisions implementing Annex V.7

 Ships 

that are specifically exempted from MARPOL, or the Antarctic Protocol, are also exempted from 

the requirements of APPS. 

In addition to implementing the requirements of MARPOL, described above, APPS 

establishes a number of administrative requirements regarding inspections, penalties for 

violations, procedures for legal actions, and public education requirements (33 U.S.C. §§ 1907, 

1908, 1910, and 1915). 

 

7

 However, all surface ships and submersibles owned or operated by the Department of the Navy are required to 

comply with the special area requirements of Annex V. Unique vessels that cannot fully comply with the 

requirements of Annex V are permitted to discharge some types of garbage without regard to the requirements of 

Annex V. See 33 U.S.C. § 1902(d)(2). 
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6.2.1.1 U.S. Coast Guard Implementing Regulations 

The U.S. Coast Guard implements APPS through its regulations at 33 CFR Part 151. 

These regulations apply to every ship required to comply with Annex I, II, or V of MARPOL (33 

CFR § 151.03).8

6.2.1.1.1 Annex I Implementation—Prevention of Oil Pollution 

The requirements of Annex I of MARPOL, pertaining to the prevention of oil pollution 

from ships, are implemented by the U.S. Coast Guard though its regulations at 33 CFR §§ 

151.09–151.29. This section of the regulations, with the exception of the oil pollution emergency 

plan requirements,9

 is applicable to ships that are operated under the authority of the United 

States and that engage in international voyages, are certificated for ocean service, are certificated 

for coastwise service beyond three nautical miles from land, or are operated at any time seaward 

of the outmost boundary of the territorial seas of the United States. The regulations also apply to 

ships operated under the authority of another country while in the navigable waters of the United 

States or while at a port or terminal under U.S. jurisdiction (33 CFR § 151.09(a)). The 

regulations do not apply to warships, naval auxiliary, or other ships owned or operated by a 

country when engaged in noncommercial service; Canadian or U.S. ships operating exclusively 

on the Great Lakes or their connecting tributary waters or on any internal waters of the United 

States or Canada; or any ships specifically excluded by MARPOL. 

The Coast Guard’s requirements for oil discharges from ships other than oil tankers10 are 

very similar to Annex I’s requirements. The Coast Guard’s regulations apply to the same size 

ships regulated under MARPOL; however, the Coast Guard also distinguishes vessels depending 

on how far off shore they are operating: 

 When more than 12 nautical miles from the nearest land, any discharge of oil or oily 

mixtures must meet the following conditions: 

o The discharge must not originate from cargo pump room bilges. 

o The discharge must not be mixed with oil cargo residues. 

o The ship must not be within a special area. 

8

 On December 18, 2009, EPA finalized regulations to implement the air emission requirements of APPS (which 

themselves implement MARPOL Annex VI). The final rule is not scheduled to appear in the Federal Register until 

the end of February 2010. To see a pre-publication copy of the rule, please visit EPA’s website at 

http://www.epa.gov/OMS/oceanvessels.htm#regs. 

9

 The shipboard oil pollution emergency plan requirements at 33 CFR §§ 151.26-151.29 apply to all U.S.- and 

foreign-operated oil tankers of 150 gt and above and all other ships of 400 gt and above. The same exceptions 

described in the text apply, with the additional exception that barges or other ships constructed or operated in such a 

manner that no oil in any form can be carried aboard are also exempted from the requirements (33 CFR § 151.09(c)–

(d)). 

10 The requirements for oil tankers are found in a separate section of the regulations (33 CFR Part 157). 
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o The ship must be proceeding en route.

11 

o The oil content of the effluent without dilution must be less than 15 ppm. 

o The ship must be operating oily-water separating equipment, a bilge monitor, a 

bilge alarm, or a combination of the three (33 CFR § 151.10(a)). 

 When within 12 nautical miles from the nearest land, any discharge of oil or oily 

mixtures must meet all of the above requirements, with the additional requirement that 

the oily-water separating equipment be equipped with a U.S. government- or IMOapproved 15 ppm bilge alarm (33 CFR § 151.10(b)). 

Ships of 400 gt or above and oil tankers are prohibited from discharging oil or oily 

mixtures while operating in a special area, as defined in 33 CFR § 151.13(a). However, if the 

discharge is of processed bilgewater from machinery space bilges, ships of this size may 

discharge in special areas if all of the above requirements are met and the ship is equipped with 

an automatic shut-off device that will engage when the oil content of the effluent exceeds 15 

ppm (33 CFR § 151.13). Ships of 400 gt or less, other than oil tankers, may discharge in special 

areas only if the undiluted oil content of their effluent is 15 ppm or less. If a ship cannot meet the 

discharge requirements, the oily mixtures must be retained onboard or discharged to a reception 

facility (33 CFR § 151.10(f)). 

As with MARPOL, these discharge requirements do not apply where the discharge is 

necessary to secure the safety of the ship or save life at sea, or if the discharge results from 

damage to the ship (provided reasonable precautions were taken after the occurrence of the 

damage or discovery of the discharge to prevent or minimize the discharge, and the owner or 

master of the ship did not act with intent to cause damage, or recklessly and with knowledge that 

damage would probably result) (33 CFR § 151.11). 

The regulations also implement the reporting, survey, certification, inspection and 

enforcement, recordkeeping, and planning requirements of Annex I, described above (33 U.S.C. 

§§ 151.15, 151.17, 151.19, 151.23, 151.25–151.28). 

6.2.1.1.2 Annex II Implementation—Prevention of Pollution from Noxious Liquid 

Substances 

The requirements of Annex II of MARPOL, pertaining to the discharges of noxious 

liquid substances from ships, are implemented by the U.S. Coast Guard primarily through its 

regulations at 33 CFR §§ 151.30–151.49, although some requirements are also at 46 CFR Parts 

11 A ship not traveling en route may discharge oil and oily mixtures, provided it is equipped with a U.S. 

government-or IMO-approved 15 ppm bilge alarm and complies with other requirements of 33 CFR § 151.10. 33 

CFR § 151.10(d). 
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151 and 153.12 Which regulations are applicable to a particular vessel depends on the specific 

substance(s) the ship is carrying (33 CFR § 151.31). 

The primary regulations at 33 CFR §§ 151.30–151.49 are applicable to the same ships 

subject to the implementing regulations for Annex I (i.e., all ships operated under the authority of 

the United States that are engaged in international voyages, certificated for ocean service, 

certificated for coastwise service beyond 3 nautical miles from land, or operated seaward of the 

outermost boundary of the territorial sea of the United States). These requirements also apply to 

ships operated under the authority of another country while in U.S. waters or while at a port or 

terminal under U.S. jurisdiction (33 CFR § 151.30(a)). The same exemptions that apply to Annex 

I’s implementing regulations also apply here, with an added exemption for tank barges whose 

certificates are endorsed by the Coast Guard for a limited short protected coastwise route if the 

barge is constructed and certificated primarily for service on inland routes (33 CFR § 151.30(b)). 

U.S. oceangoing ships are prohibited from carrying certain Category C and D NLS, 

identified at 33 CFR §§ 151.47–151.49, in cargo tanks unless those tanks have been endorsed 

through a Certificate of Inspection to carry those substances. Foreign ships and ships traveling to 

foreign destinations must meet additional certification requirements (33 CFR §§ 151.33–151.35). 

Ships carrying Category C or D oil-like substances must also meet additional operating 

requirements, such as having monitoring and control equipment installed and meeting damage 

stability requirements (33 CFR § 151.37). 

To discharge NLS residue to the sea, the ship must be at least 12 nautical miles from the 

nearest land. Additional depth restrictions and maximum rates of discharge also apply for 

particular types of residue (46 CFR § 153.1128). Discharges of NLS residue from slop tanks are 

also subject to additional restrictions (46 CFR § 153.1126). If a ship cannot meet these discharge 

requirements, the NLS residue must be retained onboard or discharged to a reception facility. If 

the NLS cargo or residue is being transferred at a port or terminal of the United States, the 

operator of the ship must notify the port or terminal at least 24 hours in advance of the name of 

the ship and the name, category, and volume of the NLS cargo that will be unloaded (33 CFR § 

151.43). 

6.2.1.1.3 Annex V Implementation – Prevention of Garbage Pollution from Ships 

The requirements of Annex V of MARPOL, pertaining to garbage pollution from ships, 

are implemented by the Coast Guard through regulations found at 33 CFR §§ 151.51–151.77. 

These regulations apply to all ships of U.S. registry or nationality, all ships operated under the 

authority of the United States (including recreational and uninspected vessels), and all ships 

12 Coast Guard regulations currently implement a prior version of Annex II. Parts 151 and 153 are currently under 

revision to implement revised Annex II, dated November 1, 2004. Navigation and Vessel Inspection Circular No. 

03-06 contains guidance on the Coast Guard’s implementation of revised Annex II. 
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operating in the navigable waters or the Exclusive Economic Zone of the United States. They do 

not apply to warships, naval auxiliary, other ships owned or operated by the United States when 

engaged in noncommercial service, or any ship specifically excluded by MARPOL (33 CFR § 

151.51). 

The regulations prohibit the discharge of garbage into the navigable waters of the United 

States by any person onboard any ship unless the requirements of MARPOL are followed. 

Commercial ships are permitted to discharge bulk dry cargo residues into the Great Lakes 

provided certain requirements are met (33 CFR § 151.66). As with Annex V, the discharge of 

plastic or garbage mixed with plastic into the sea or navigable waters of the United States is 

flatly prohibited (33 CFR § 151.67). 

The Coast Guard’s regulations also implement the recordkeeping, waste management 

plan, placard, inspection for compliance and enforcement, and reporting requirements of 

MARPOL (33 CFR §§ 151.55, 151.57, 151.59, 151.61, and 151.65). 

As with MARPOL, oil and grease are pollutants of potential concern found in incidental 

discharges that would be directly regulated by APPS and the relevant implementing regulations. 

Like MARPOL, APPS and its relevant implementing regulations may indirectly regulate other 

pollutants found in incidental vessel discharges, such as metals, to the extent that they are found 

in any of the noxious liquid substances or garbage categorized under Annex II and Annex V or 

the Coast Guard’s implementing regulations and are prevented from entering incidental 

discharge streams. As with MARPOL, APPS and the relevant implementing regulations only 

apply to those vessels that meet the size thresholds established in MARPOL. 

6.2.2 Clean Water Act (CWA) §§ 311, 312/Oil Pollution Control Act

6.2.2.1 CWA § 311, Oil and Hazardous Substances 

Clean Water Act (CWA) § 311 (Oil and Hazardous Substances Liability) states that it is 

U.S. policy that there should be no discharges of oil or hazardous substances into waters of the 

U.S., adjoining shorelines, into or upon the waters of the contiguous zone, and in certain other 

specified instances, except where permitted under MARPOL/APPS or where in quantities the 

president has, by regulation, determined not to be harmful (33 U.S.C. §§ 1321(b)(1)–(b)(3)). The 

term “discharge” excludes discharges in compliance with a National Pollutant Discharge 

Elimination System (NPDES) permit under CWA § 402; discharges anticipated in the NPDES 

permitting process; and discharges incidental to mechanical removal authorized by the president 

to remove or mitigate a discharge (33 U.S.C. § 1321(a)(2)). A list of hazardous substances EPA 

has designated under the CWA can be found at 40 CFR § 116.1.13 

 

13 EPA’s regulations implementing § 311 are located at 40 CFR § 110–117.
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Any person in charge of a vessel or onshore facility must immediately notify the 

appropriate federal agency upon discovering any harmful discharge of oil or hazardous substance 

from the vessel or facility under their control. The federal agency will then notify appropriate 

state agencies. Any person in charge of a vessel or onshore facility who discharges in violation 

of the CWA and fails to provide immediate notification to the appropriate federal agency shall, 

upon conviction, be fined or imprisoned, or both (33 U.S.C. § 1321 (b)(5)). Owners or operators 

must respond immediately to any discharge or threat of discharge of oil (33 U.S.C. § 1321 

(c)(5)). 

This section of the CWA also requires the president to prepare and publish a National 

Contingency Plan (NCP) for the removal of oil and hazardous substances (33 U.S.C. § 

1321(d)(1)). The NCP must include: 

 an assignment of duties and responsibilities among federal departments and agencies; 

 identification, procurement, maintenance, and storage of equipment and supplies; 

 establishment of Coast Guard strike teams; a system of surveillance and notice; 

 establishment of a national center to provide coordination and direction for operations 

in carrying out the plan; 

 procedures and techniques to be employed in identifying, containing, dispersing, and 

removing oil and hazardous substances; 

 a schedule of which chemicals and dispersants may be used in which waters to 

mitigate any spills; 

 a system for states affected by a discharge to act to remove the discharge; 

establishment of criteria and procedures to ensure immediate and effective federal 

identification of and response to discharges or threats of discharges that will endanger 

public health; 

 establishment of procedures and standards for removing a worst case discharge of oil; 

 designation of federal officials to act as on-scene coordinators; establishment of 

procedures for the coordination of activities; and a fish and wildlife response plan (33 

U.S.C. § 1321(d)(2)). The full text of the NCP can be found at 40 CFR Part 300. 

6.2.2.2 Oil Pollution Control Act 

The Oil Pollution Control Act of 1990 (OPA), 33 U.S.C. §§ 2701–2762, was passed as an 

almost immediate response to the Exxon Valdez tanker accident, which caused more than 11 

million gallons of crude oil to spill into Alaska’s Price William Sound. The OPA expanded the 
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federal government’s authority to respond to oil spills, provided the money and resources 

necessary for the government to exercise its authority, and required revisions to the National Oil 

and Hazardous Substances Pollution Contingency Plan to broaden coordination and preparedness 

planning requirements. The OPA also increased penalties for regulatory noncompliance, 

broadened the response and enforcement authorities of the federal government, and preserved 

state authority to establish laws governing oil spill prevention and response. Additionally, the 

OPA created the Oil Spill Liability Trust Fund to help fund some of the cleanup costs and repair 

damage resulting from oil discharges (discussion on the exact requirements of the Fund has been 

omitted). The requirements of the OPA apply to all vessels, onshore facilities, offshore facilities, 

deepwater ports, and pipelines. 

The OPA is implemented by both EPA and the U.S. Coast Guard. EPA regulations on oil 

spill prevention and response are found in 40 CFR Parts 112 and 300. U.S. Coast Guard 

regulations regarding oil spill prevention and response plans are located at 33 CFR §§ 155.1010–

155.2230 and 49 CFR §§ 130.1–130.33. 

6.2.2.3 CWA § 312, Marine Sanitation Devices 

The CWA also requires EPA, in consultation with the Coast Guard, to promulgate federal 

performance standards for marine sanitation devices. These standards must be designed to 

prevent the discharge of untreated or inadequately treated sewage into or upon the navigable 

waters from vessels (33 U.S.C. § 1322(b)). Both the EPA and Coast Guard have promulgated 

regulations implementing this provision. The Coast Guard’s regulations can be found at 33 CFR 

Part 159, while EPA’s can be found at 40 CFR Part 140. 

Because discharges of sewage were exempted by Congress from this study, as such 

discharges are not incidental to the normal operation of a vessel, an in-depth discussion of this 

provision and its implementing regulations has been omitted. 

6.2.3 Organotin Antifouling Paint Control Act

The Organotin Antifouling Paint Control Act of 1988, 33 U.S.C. §§ 2401–2410, prohibits 

the use of antifouling paints containing organotin such as tributyltin (TBT) on vessels that are 25 

meters or less in length, unless the vessel hull is aluminum or the paint is applied to an outboard 

motor (33 U.S.C. § 2403(b)). The term vessel is defined to include “every description of 

watercraft or other artificial contrivance used, or capable of being used, as a means of 

transportation on water” (33 U.S.C. § 2402(11)). 

The Act also prohibits the sale, purchase, and application of antifouling paint containing 

organotin unless the paint has been approved by EPA as being a qualified antifouling paint. 

Under the Act, “antifouling paint” includes any “coating, paint, or treatment that is applied to a 

vessel to control fresh water or marine fouling organisms” (33 U.S.C. § 2402(2)). A qualified 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States 

447 

antifouling paint is one that has a release rate of not more than 4.0 micrograms per square 

centimeter per day (33 U.S.C. § 2402(6)). 

As noted in Section 6.1.2, in September 2008 the United States Senate gave its advice 

and consented to ratification of the International Convention on the Control of Harmful AntiFouling Systems on Ships. However, the United States will not deposit its instrument of 

ratification with the IMO until Congress adopts the necessary implementing legislation. 

Implementing legislation is pending. See Clean Hull Act of 2009, H.R. 3618, 111th Congress 

(1st Session 2009). EPA has already canceled all U.S. FIFRA registrations for TBT antifouling 

paints. The last cancellation became effective December 31, 2005. Any current use of these 

products is dwindling because there are very limited or no stocks of the products remaining on 

the market. Also, the International Convention has made it difficult and undesirable for vessel 

owners/operators to use TBT antifouling paints. 

Additionally, as discussed above, EPA has prohibited the use of TBT or other organotins 

as biocides on any vessel covered by the Vessel General Permit. 

The Organotin Antifouling Paint Control Act only regulates the use of organotin, it does 

not extend to other pollutants of potential risk that may be present in antifouling hull coatings. 

Although the Act banned new applications of antifouling hull coatings containing organotin, 

organotin may still be present in residual quantities on older vessels. 

6.2.4 National Invasive Species Act

The primary purpose of the National Invasive Species Act of 1996 (NISA), which 

reauthorized and amended the Non-Indigenous Aquatic Nuisance Prevention and Control Act of 

1990, is to prevent, monitor, and control the unintentional introduction and dispersal of 

nonindigenous species into waters of the United States through ballast water and other pathways 

(16 U.S.C. § 4701(b)). The voluntary guidelines and mandatory regulations required by NISA 

apply, with only few exceptions, to all vessels equipped with ballast water tanks that operate in 

waters of the United States.14 

Because ballast water was specifically exempted from this study by P.L. 110–299, an indepth discussion of the ballast water requirements of NISA has been omitted.15 In addition to 

ballast water guidelines, however, NISA requires the development of guidelines to prevent the 

spread of nonindigenous species from other vessel operations, such as hull fouling. 

 

14 The Act requires that the Coast Guard and the Department of Defense implement ballast water management 

programs for seagoing vessels under their control (16 U.S.C. § 4713). 

15 For the ballast water requirements, see the text of the Act at 16 U.S.C. §§ 4701–4751 as well as the Coast Guard’s 

regulations at 33 CFR Part 151, subparts C and D. 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

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For example, the Coast Guard’s regulations require that all vessels equipped with ballast 

water tanks that operate in the waters of the U.S. have fouling organisms removed from their 

hulls, piping, and tanks on a regular basis, and that any removed substances be disposed of in 

accordance with local, state, and other federal regulations (33 CFR § 151.2035(a)(6)). 

The National Invasive Species Act does not directly regulate any of the pollutants of 

potential concern discussed in this study; the Act is focused solely on preventing the spread of 

nonindigenous species. 

6.2.5 Hazardous Materials Transportation Act

The Hazardous Materials Transportation Act, 49 U.S.C. §§ 5101 et seq., regulates the 

transportation of hazardous material in interstate, intrastate, and foreign commerce. The Act, 

which implements MARPOL Annex III, includes registration, reporting, and recordkeeping 

requirements and applies to any vessel involved in transporting hazardous material in commerce. 

The Act, and its implementing Hazardous Materials Regulations (HMR), 49 C.F.R. parts 

171-180, apply to anyone who transports hazardous material in commerce, causes hazardous 

material to be transported in commerce, is involved in any way in the design and manufacture of 

containers used to transport hazardous material, prepares or accepts hazardous material for 

transport in commerce, is responsible for the safety of transporting hazardous material in 

commerce, or certifies compliance with any requirement under the Act (49 U.S.C. § 5103(b)). 

Anyone transporting a hazardous material (including a hazardous waste) by vessel must 

file a registration statement with the Department of Transportation (49 U.S.C. § 5108), and must 

also follow requirements addressing personnel and personnel training, inspections, equipment, 

and safety procedures (49 U.S.C. § 5106). 

The Hazardous Materials Transportation Act does not directly regulate the discharge of 

any pollutants of potential concern. Instead, the requirements of the Act ensure that hazardous 

materials are transported safely and securely, thereby lessening the likelihood that hazardous 

pollutants will contaminate incidental vessel discharges. 

6.2.6 National Marine Sanctuaries Act

The National Marine Sanctuaries Act, 16 U.S.C. § 1431 et seq., authorizes the Secretary 

of Commerce to designate and protect areas of the marine environment that are of special 

national significance because of their conservation, recreational, ecological, historical, scientific, 

educational, cultural, archeological, or esthetic qualities (16 U.S.C. § 1431(a)). The Act is 

implemented by the National Oceanic and Atmospheric Administration (NOAA) through its 

regulations at 15 CFR Part 922. 
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Regulation under Federal Law or a Binding International Obligation of the United States 

449 

The National Marine Sanctuary Program currently consists of 13 national marine 

sanctuaries and one marine national monument: Thunder Bay (Great Lakes), Stellwagen Bank 

(Massachusetts), Monitor (an archeological site off the coast of Virginia), Gray’s Reef (Georgia), 

the Florida Keys, Flower Garden Banks (Gulf of Mexico), Fagatele Bay (American Samoa), 

Hawaiian Islands/Humpback Whale, Papahānaumokuākea National Monument, Channel Islands, 

Monterey Bay (California), Gulf of the Farallones (California), Cordell Bank (California), and 

the Olympic Coast (Washington). 

Additional restrictions and requirements may be imposed on vessel owners/operators who 

operate in or around these areas. For example, NOAA’s regulations pertaining to the Hawaiian 

Islands/Humpback Whale National Marine Sanctuary prohibit the discharge or deposition of any 

material or other matter in the sanctuary, or outside the sanctuary if the discharge or deposit will 

subsequently enter and injure a humpback whale or humpback whale habitat, unless that 

discharge or deposition is carried out according to the terms or conditions of a federal or state 

permit (15 CFR § 922.184(a)(5)). Vessels operating in this area must also avoid coming within 

100 yards of any humpback whale (except when authorized under the Marine Mammal 

Protection Act and Endangered Species Act) (15 CFR § 922.184(a)(1)). 

The National Marine Sanctuaries Act does not directly regulate by name the discharge of 

any of pollutants of potential concern. However, the additional restrictions and requirements 

developed for many of the specific sanctuaries include direct prohibitions on the discharge of 

certain materials. For example, the regulations specific to the Channel Islands National Marine 

Sanctuary prohibit the discharge or deposition of “any material or other matter” except fish or 

fish parts, and water and “other biodegradable effluents incidental to vessel use.” (15 CFR § 

922.72(a)(2)). The regulations governing the Gulf of the Farallones National Marine Sanctuary 

prohibit the discharge “from within or into the Sanctuary, other than from a cruise ship, any 

water or other matter except: ... clean vessel deck wash down, clean vessel engine cooling water, 

clean vessel generator cooling water, clean bilge water, or anchor wash.” (15 CFR § 

922.82(a)(2)(iii)). 

6.2.7 Resource Conservation and Recovery Act

The Resource Conservation and Recovery Act (RCRA), 42 U.S.C. § 6901–6992k, was 

enacted in 1976 to amend the Solid Waste Disposal Act of 1965. RCRA was designed to 

minimize the hazards of waste disposal; conserve resources through waste recycling, recovery, 

and reduction; and ensure that waste management practices are protective of human health and 

the environment. The RCRA requirements apply to vessels to the extent that they create, carry, 

or dispose of solid or hazardous wastes. 

By regulation, a “hazardous waste” under RCRA is one that falls on any number of lists 

EPA has created, or one that exhibits at least one of the following characteristics: ignitibility, 

corrosivity, reactivity, or toxicity (40 CFR § 261.3). A “solid waste” is any material that has been 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States 

450 

discarded; including any material that has been abandoned or recycled or is inherently waste-like 

(40 CFR § 261.2). 

Subtitle C of RCRA establishes a “cradle-to-grave” system that addresses hazardous 

waste management from the moment of generation through ultimate disposal. The provisions of 

Subtitle C apply to all generators and transporters of hazardous waste (42 U.S.C. §§ 6921–6939). 

A “generator” is someone “whose act or process produces hazardous waste...or whose act first 

causes a hazardous waste to become subject to regulation” (40 CFR § 260.10). A “transporter” is 

anyone “engaged in the offsite transportation of hazardous waste by air, rail, highway, or water” 

(40 CFR § 260.10). A generator of a hazardous waste is subject to the requirements of subtitle C 

on packaging, labeling, marking, placarding, storage, recordkeeping, and inspection (40 C.F.R. 

part 262, subpart C). Additionally, both generators and transporters are required to use a manifest 

system to ensure that all hazardous waste subject to transport arrives at the designated treatment, 

storage, or disposal facility (42 U.S.C. §§ 6922(a)(5), 6923(a)(3)). 

Hazardous waste generated on public vessels (i.e., those vessels owned or chartered by 

the United States and engaged in noncommercial service) is not subject to the storage, manifest, 

inspection, or recordkeeping requirements of RCRA until the waste is transferred to a shore 

facility, unless the waste is stored on the vessel for more than 90 days after the vessel is no 

longer in service or the waste is transferred to another public vessel within the territorial waters 

of the United States and is stored on that vessel for more than 90 days after the date of transfer 

(42 U.S.C. § 6939d). In addition, any "industrial discharges which are point sources subject to 

[NPDES[ permits" are excluded from the definition of solid waste under RCRA (42 U.S.C. § 

6903(27)). 

RCRA's primary effect on study vessel discharges is indirect; RCRA's extensive 

requirements concerning the handling of any hazardous waste generated, stored or transported 

onboard the vessel ensure that such wastes do not make their way into the study discharges. 

However, because study vessel discharges are not subject to NPDES permitting, they would not 

qualify for the "industrial point source discharge exclusion" and, thus, could be subject to 

applicable RCRA requirements. 

6.2.8 Federal Insecticide, Fungicide, and Rodenticide Act 

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. § 136–136y, 

provides the basis for the regulation, sale, distribution, and use of pesticides in the United States. 

FIFRA authorizes EPA to review and register pesticides for specified uses, as well as suspend or 

cancel the registration of a pesticide if subsequent information shows that continued use would 

pose unreasonable risks. 

One of FIFRA’s primary requirements is that pesticides be registered by EPA before they 

may be sold or distributed in the United States. To obtain a registration, a pesticide manufacturer 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States 

451 

must submit a registration application to EPA that includes a proposed label containing specific 

directions for use of the pesticide. The application must also include or cite scientific data 

sufficient to support an EPA finding that the pesticide, when used according to label directions, 

will not cause unreasonable adverse effects on the environment (a risk benefit standard that takes 

into account the social, economic, and environmental costs and benefits associated with use of 

the pesticide). It is a violation of FIFRA to use a pesticide in a manner inconsistent with its label. 

Pesticides may be registered as either general use or restricted use. A general use 

pesticide may be applied by anyone, while a restricted use pesticide may only be applied by 

certified applicators (applicators specifically certified by EPA or a state to apply restricted use 

pesticides) or persons working under the direct supervision of a certified applicator. 

Vessels that use FIFRA-registered products onboard or as antifouling compounds must 

follow all FIFRA labeling requirements. 

FIFRA governs the use of pesticides, including those applied aboard vessels in the United 

States. Although FIFRA does not directly regulate vessel discharges, the requirements of FIFRA 

require that pesticides are used in accordance with their label instructions, which may indirectly 

limit the quantity of pesticide related pollutants that end up in incidental vessel discharges. 

6.3 ADDITIONAL INTERNATIONAL AND FEDERAL LAWS

EPA has identified a number of international and federal laws that fall outside the scope 

of this study, but which merit mentioning for information purposes. 

6.3.1 International Convention on the Prevention of Marine Pollution by Dumping of 

Wastes and Other Matter

The International Convention on the Prevention of Marine Pollution by Dumping of 

Wastes and Other Matter, commonly referred to as the London Convention, entered into force in 

1975. The London Convention prohibits the dumping of certain hazardous material and requires 

a permit for other identified materials and wastes. In 1996, the IMO adopted a more stringent 

protocol, which took effect in 2006. The United States is a party to the original London 

Convention but has not ratified the 1996 protocol. The United States implements the original 

London Convention through the Marine Protection, Research and Sanctuaries Act, 33 U.S.C. §§ 

1401–1445. The London Convention and Protocol do no apply, however, to the disposal into the 

sea of matter incidental to or derived from the normal operation of vessels. 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States 

452 

6.3.2 International Convention on Oil Pollution, Preparedness, Response and 

Cooperation

To emphasize the importance of effective preparation for combating oil spills, in 1990 the 

IMO adopted the International Convention on Oil Pollution, Preparedness, Response and 

Cooperation (OPRC). The OPRC, which entered into force in 1995 and has been ratified by the 

United States, establishes a global framework for international cooperation in responding to oil 

pollution. OPRC includes requirements such as onboard oil pollution emergency plans, the 

reporting and prompt investigation of spills, and coordinated response actions. 

6.3.3 International Convention Relating to Intervention on the High Seas in Cases of 

Oil Pollution Casualties

The International Convention Relating to Intervention on the High Seas in Cases of Oil 

Pollution Causalities was adopted by the IMO in 1969. The Convention entered into force in 

1975 and has been ratified by the United States. The purpose of the Convention is to affirm the 

right of coastal states to take such measures on the high seas as may be necessary to prevent, 

mitigate, or eliminate danger to their coastlines or related interests from spills of oil and other 

substances following marine accidents. 

6.3.3.1 Intervention on the High Seas Act 

The Intervention on the High Seas Act, 33 U.S.C. §§ 1471–1487, authorizes the Coast 

Guard to intervene whenever there is a ship collision, stranding, or other incident or occurrence 

that creates a grave and imminent danger to the coastline or related interests of the United States. 

This Act implements the International Convention Relating to Intervention on the High Seas in 

Cases of Oil Pollution Casualties. 

6.3.4 Comprehensive Environmental Response, Compensation, and Liability Act 

The Comprehensive Environmental Response, Compensation, and Liability Act 

(CERCLA), 42 U.S.C. §§ 9601–9675, regulates the release or substantial threat of release of 

hazardous substances (or those dangerous to public health or welfare) into the environment. The 

liability provisions of CERCLA are expressly applicable to releases from vessels. Additionally, 

CERCLA requires any person in charge of a vessel to immediately notify the National Response 

Center as soon as he has knowledge of any release of a hazardous substance from that vessel in a 

quantity equal to or greater than a reportable quantity (42 U.S.C. §§ 9602, 9603(a)).
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States 

453 

6.3.5 CWA § 402, National Pollutant Discharge Elimination System (NPDES)

In December 2008, EPA issued an NPDES general permit, pursuant to CWA § 402, that 

is applicable to all vessels operating in a capacity as a means of transportation (except 

recreational vessels as defined in CWA § 502[25] and study vessels (except for their ballast 

water discharges) that have discharges incidental to their normal operations into waters of the 

United States. The permit establishes technology-based effluent limits for 26 different types of 

vessel discharges in the form of best management practices (BMPs), as well as water qualitybased effluent limitations. The permit also includes inspection, monitoring, reporting, and 

recordkeeping requirements. 

For study vessels, coverage under the general permit is limited to ballast water 

discharges. For that reason, a lengthy discussion of the permit falls outside the scope of P.L. 

110–229. For more information about this permit, please visit: www.epa.gov/npdes/vessels. 

6.3.6 Title XIV of the Consolidated Appropriations Act, 2001—Certain Alaskan 

Cruise Ship Operations

Title XIV sets standards for sewage and graywater discharges from large cruise ships 

(those authorized to carry 500 passengers or more for hire) while operating within certain waters 

in Alaska. The law prohibits these large cruise ships from discharging untreated sewage while 

operating in particular waters, but allows the discharge of treated sewage and graywater if certain 

conditions are met. 

6.3.7 Toxic Substances Control Act

The Toxic Substances Control Act (TSCA), 15 U.S.C. §§ 2601–2695, was enacted in 

1976 to provide EPA authority to collect information regarding chemical substances and to 

regulate unreasonable risks from the manufacture, import, processing, distribution in commerce, 

or use or disposal of chemical substances in the United States. EPA implements TSCA through 

its regulations at 40 CFR Parts 700–766. 

TSCA addresses the production, importation, distribution in commerce, use, and disposal 

of chemical substances and mixtures of chemical substances generally, and also specifically 

regulates the following chemical substances: polychlorinated biphenyls (PCBs), asbestos, radon, 

lead, and mercury. TSCA requires EPA to maintain an inventory of each chemical substance 

manufactured or processed in the United States. Chemical substances as defined under TSCA do 

not include substances regulated under other specified laws, such as food additives, pesticides, 

drugs, cosmetics, tobacco, nuclear material, and munitions. Chemical substances listed on the 

inventory are considered “existing,” and those not listed are considered “new.” Existing 

substances are subject to any regulations or orders the Agency has issued for those substances. 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States 

454 

 

New substances are subject to premanufacture notice requirements, described in Section 5 of 

TSCA. 

EPA can collect information on chemical substances and chemical mixtures under TSCA, 

and EPA has the authority to regulate the use or disposal of chemicals or chemical mixtures if 

EPA finds that activity presents an unreasonable risk of injury to health or the environment. 

TSCA would allow EPA to regulate chemicals contained in incidental discharges were the 

Agency to find it meets this standard. 

6.4 APPLICATION OF LEGAL AUTHORITIES TO DISCHARGES INCIDENTAL TO 

THE NORMAL OPERATION OF STUDY VESSELS

The preceding subsections discussed a number of international treaties and domestic laws 

that have been adopted to address the environmental impacts of vessel discharges. These 

subsections also include a summary of how each of the described treaties, statutes, and 

regulations would regulate specific incidental vessel discharges and specific vessels. The 

following tables provide additional information, in greater specificity, regarding the applicability 

of each of the international treaties and domestic laws to incidental vessel discharges. 

Table 6-1 shows which international treaties and federal laws apply to the types of 

incidental discharges that might occur on study vessels. The purpose of this table is to summarize 

the preceding discussion and make clear which incidental discharges are regulated or potentially 

regulated by existing international and domestic laws.16 

Table 6-2 shows which treaties, statutes, and regulations apply to certain size vessels. 

This table is not meant to imply that each class of vessel shown is covered by a particular 

statute/treaty in all instances. Whether a particular law/treaty applies to a particular vessel 

depends on vessel-specific circumstances, such as the vessel’s size and class, as well as where 

that vessel is operating and what it is discharging. In many instances the treaties/laws shown 

classify vessels by weight rather than length. For the purposes of this table, EPA estimated the 

length that would correspond with a given vessel weight. 

16 Note that for many of the authorities listed, application may depend on vessel- or discharge-specific circumstances 

(e.g., at what concentration certain substances are present in the discharge). 
Chapter 6 – Analysis of the Extent to which Incidental Disch

Regulation under Federal Law or a Binding International O

Table 6. 1. International Treaties and Federal Laws Applicable to Discharges Incidental to the Normal Operation of Vessels

Deck Washdown and Runoff & Above Water Line Hull 

Cleaning 

Bilgewater 

Shaft Packing Gland Effluent 

Ballast Water1

Antifouling Leachate from Antifouling Hull Coatings 

Aqueous Film-Forming Foam (AFFF) 

Boiler /Economizer Blowdown 

Cathodic Protection 

Chain Locker Effluent 

Controllable Pitch Propeller and Thruster Hydraulic 

Fluid and Other Oil to Sea Interfaces 

Distillation and Reverse Osmosis Brine 

Elevator Pit Effluent 

Firemain Systems 

Fresh-Water Layup 

Gas Turbine Water Wash 

Graywater 

Motor Gasoline and Compensating Discharge 

Non-Oily Washwater 

Refrigeration and Air Condensate Discharge 

Seawater Cooling Overboard Discharge 

Seawater Piping Biofouling Prevention 

Boat Engine Wet Exhaust 

International Convention for the Prevention of Pollution from Ships (MARPOL) 

b, c, d b, c b, c b b b b b, c B b b c b b 

International Convention on the Control of Harmful Anti-Fouling Systems on Ships e e e International Convention for the Safety of Life at Sea (SOLAS)*

(*) SOLAS includes the ISM Code, which calls for a management system to minimize pollutants in vessel discharges. The specifics of e

vary by vessel. 

455 
Chapter 6 – Analysis of the Extent to which Incidental Disch

Regulation under Federal Law or a Binding International O

Table 6.1. International Treaties and Federal Laws Applicable to Discharges Incidental to the Normal Operation of Vessels

456 

Boundary Waters Treaty / Great Lakes Water Quality Agreement †St. Lawrence Seaway Regulations dAct to Prevent Pollution from Ships (APPS) 

b, c, d b, c b, c b b b b b, c B b b b b 

CWA § 311: Oil & Hazardous Substances / Oil Pollution Control Act b b b b b b b b b B b b b b Organotin Antifouling Paint Control Act e 

a, e 

a, e 

Hazardous Materials Transportation Act f f f f f f National Marine Sanctuaries Act g g g g g g g g g g g g g g G g g g g g g g Resource Conservation and Recovery Act (RCRA) f f f f f f f f f f F f f f f f f Toxic Substances Control Act (TSCA) f f f f f f f f f f F f f f f f f Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) a a a 

Key for Table 6.1:

a = regulates pesticide constituents that may be found in discharge b = discharge regulated by law/treaty to the extent that it contains oil c = discharge regulated by law/treaty to the extent that it prevents contamination by noxious liquid substances d = discharge regulated by law/treaty to the extent that it prevents contamination from garbage e = regulates antifouling constituents that may be found in discharge f = regulates toxic substances that may be found in discharge g = application of law/treaty dependent on requirements specific to the vessel’s location h = the discharge is regulated by this treaty, but the United States has not ratified the relevant annex 

† The Boundary Waters Treaty protects the boundary waters of the United States and Canada from pollution generally. 
Chapter 6 – Analysis of the Extent to which Incidental Discharges are currently subject to 

Regulation under Federal Law or a Binding International Obligation of the United States

Table 6.2. International Treaties and Federal Laws Applicable to Vessels (by Length) 

 

Study Vessels Less 

Than 79 Feet in 

Length 

Study Vessels Greater 

Than 79 Feet in 

Length 

Nonstudy Vessels 

Greater Than 79 Feet

in Length 

International Convention for the Prevention of Pollution 

from Ships (MARPOL 73/78)* 

Annex I Xx x* x 

Annex II Xx x x 

Annex III X x x 

Annex V Xx x x 

International Convention on the Control of Harmful AntiFouling Systems on Ships X x x 

International Convention for the Safety of Life at Sea 

(SOLAS) 

Boundary Waters Treaty / Great Lakes Water Quality 

Agreement X x x 

St. Lawrence Seaway Regulations X x x 

Act to Prevent Pollution from Ships (APPS) Xx x x 

CWA § 311: Oil & Hazardous Substances X x x 

CWA § 312: Marine Sanitation Devices X x x 

Oil Pollution Control Act (OPA) Xx x x 

Organotin Antifouling Paint Control Act X 

Hazardous Materials Transportation Act X x x 

National Marine Sanctuaries Act X x x 

Resource Conservation and Recovery Act (RCRA) X x x 

Toxic Substances Control Act (TSCA) X x x 

Federal Insecticide, Fungicide, and Rodenticide Act 

(FIFRA) X x x 

Key for Table 6.2:

x = law/treaty applicable to this vessel size 

xx = law/treaty applicable, but generally fewer requirements than for larger vessels 

* MARPOL treats oil tankers separately—those of 150 gt and above are subject to all of the requirements of the treaty, while 

those smaller than 150 gt have less stringent requirements. About half of the tankers weighing 150 gt are larger than 79 feet. 

457 
Chapter 7 – References 

CHAPTER 7 

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Washington, DC. Available at: www.regulations.gov. 

Alaska Trollers Association. 2010. Comments on Draft Report To Congress: Study of Discharges 

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Albert, R. 2007. The Influence of Past and Future Urbanization on Watershed Nitrogen Export and 

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Bryan, G.W., P.E. Gibbs, G.R. Burt and L.G. Hummerstone. 1986. The Decline of the Gastropod Nucella 

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Casey, D. 2007. ServicingYour Stuffing Box. BoatU.S. Available at 

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Environ. Manag. 90(8): 2460-2468. 

CRWQCB. 2005. Total Maximum Daily Load for Dissolved Copper in Shelter Island Yacht Basin, San 

Diego Bay. Basin Plan Amendment and Technical Report. California Regional Water Quality 

Control Board, San Diego Region. Resolution No. R9-2005-0019. 

Chambers, L.D., K.R. Stokes, F.C. Walsh, and R.J.K. Wood. 2006. Modern Approaches to Marine 

Antifouling Coatings. Surf. Coat. Technol. 201(6): 3642-3652. 

Chin, M. 2005. Packing Glands. BCC Maintenance Tips: Sam L. Morse Company. Available at 

http://www.samlmorse.com/forum/read/php?3,808. 

Conway, J.B. and L.P. Locke. 1994. A Final Report on Marine Fouling and In-water Hull Cleaning in 

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461 
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USEPA. 1986b. Quality Criteria for Water-1986. “Gold Book.” EPA 440/5-86-001. U.S. Environmental 

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USEPA. 1991. Technical Support Document for Water Quality-Based Toxics Control. EPA/505/2-90-

001. U.S. Environmental Protection Agency. Washington, D.C. 

USEPA. 1993. Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal 

Waters. Chapter 5: Management Measure for Marinas and Recreational Boating. EPA-840-B93-001c. U.S. Environmental Protection Agency. Washington, D.C. 

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462 
Chapter 7 – References 

USEPA. 1997. Ecological Risk Assessment Guidance for Superfund: Process for Designing and 

Conducting Ecological Risk Assessments - Interim Final. EPA 540-R-97-006. U.S. 

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USEPA. 1999. Uniform National Discharge Standards for Vessels of the Armed Forces – Phase I 

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from K. Montague and R. Petrie to D. Edwards through N. Cook, July 15, 2003. Office of 

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D.C. 

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Aquatic Organisms. EPA-822-R-03-032. U.S. Environmental Protection Agency. Washington, 

D.C. (December). 

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Washington, D.C. Available online at: 

http://www.epa.gov/waterscience/criteria/wqctable/index.html. 

USEPA. 2007. Aquatic Life Ambient Freshwater Quality Criteria – Copper; 2007 Revision. EPA-882-R07-001. U.S. Environmental Protection Agency. Washington, D.C. (February). 

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Protection Agency. Washington, D.C. (June). 

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Compression Ignition Engines. U.S. Environmental Protection Agency. Washington, D.C. 

(August). 

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463 
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464 

Valkirs, A.O., B.M. Davidson, L.L. Kear, R.L. Fransham, A.R. Zirino, and J.G. Grovhoug. 1994. 

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Division, San Diego, CA. 

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from Antifouling Paint under Laboratory and In-situ Conditions: Implications for Loading 

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75-104. 

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to Regulation in the Marine Environment. Technical Document 3140. Space and Naval Warfare 

Systems Center, San Diego, CA. 
Appendix A – List of Acronyms 

Appendix A 

List of Acronyms 

AC..........................................Air conditioning 

AFC .......................................Antifouling coating 

AFFF .....................................Aqueous film forming foam 

AFS........................................Antifouling hull systems 

AIS.........................................Aquatic Invasive Species 

ANOVA.................................Analysis of Variance 

ASTM....................................American Society for Testing and Materials 

ATSDR..................................Agency for Toxic Substances and Disease Registry 

AWT......................................Advanced Wastewater Treatment 

BOD.......................................Biochemical oxygen demand 

BLM ......................................Biotic Ligand Model 

BM .........................................Benchmark 

BMP.......................................Best management practice 

BTEX.....................................Benzene, toluene, ethylbenzene, xylene 

C.............................................Celsius 

CCC.......................................Criteria Continuous Concentration 

CFR .......................................Code of Federal Register 

CFU .......................................Colony Forming Units 

CMC......................................Criteria Maximum Concentration 

C-PORT ................................Conference of Professional Operators for Response Towing 

CRWQCB .............................California Regional Water Quality Control Board 

CSO .......................................Combined sewer overflow 

CSV........................................Comma-separated value 

COC.......................................Chain of custody

COD.......................................Chemical oxygen demand 

CTR .......................................California Toxics Rule 

CWA......................................Clean Water Act 

DBP........................................Di-n-butyl phthalate 

A-1 
Appendix A – List of Acronyms 

DC..........................................Direct current 

DEHP ....................................Bis(2-ethylhexyl) phthalate 

DO..........................................Dissolved oxygen 

DOC.......................................Dissolved organic carbon 

DOD.......................................Department of Defense 

EDD .......................................Electronic data deliverable 

EPA........................................Environmental Protection Agency 

F .............................................Fahrenheit 

fd.............................................Average dissolved fraction 

FW .........................................Fresh water 

gpd .........................................Gallons per day 

gpm .......................................Gallons per minute 

GRT.......................................Gross register ton 

HEM......................................N-hexane extractable materials 

HH ........................................Human health 

HPLC ....................................High performance liquid chromatography 

HQ .........................................Hazard quotient 

ICCP......................................Impressed current cathodic protection 

IDL ........................................Interactive Data Language 

IQR........................................Interquartile range 

kw ..........................................Kilowatt 

LCDR ....................................Lieutenant Commander 

LCPL.....................................Landing craft personnel large 

LNB .......................................Lower Newport Bay 

MA DEP................................Massachusetts Department of Environmental Protection 

MARPOL..............................International Convention for the Prevention of Pollution 

from Ships 

MDL ......................................Maximum daily load 

MdR.......................................Marina del Rey 

MF .........................................Membrane filtration 

MISLE...................................Marine Information for Safety and Law Enforcement 

A-2 
Appendix A – List of Acronyms 

MPN ......................................Most Probable Number 

MS..........................................Microsoft 

MSD.......................................Marine Sanitation Device 

MSIS......................................Marine Safety Information System 

MTBE....................................Methyl tertiary butyl ether 

ND..........................................Not detected 

NH3-N ...................................Ammonia (total, as nitrogen) 

NMMA ..................................National Marine Manufacturers Association 

NO3/NO2-N ..........................Nitrate/Nitrite (as nitrogen) 

NOAA....................................National Oceanic and Atmospheric Administration 

NP ..........................................Nonylphenol 

NPEC.....................................Nonylphenol polyethoxy carboxylate 

NPEO ....................................Nonylphenol polyethoxylate 

NRWQC................................National Recommended Water Quality Criteria 

NTU .......................................Nephelometric Turbidity Units 

O&G......................................Oil and grease 

OCPD ....................................Oceans and Coastal Protection Division 

OPEO ....................................Octylphenol polyethoxylate 

OWOW .................................Office of Wetlands, Oceans, and Watersheds 

PAH .......................................Polycyclic aromatic hydrocarbon 

PBT........................................Persistent, bioaccumulative, and toxic chemical 

PHQ.......................................Potential hazard quotient 

P.L. ........................................Public Law 

POTW ...................................Publicly owned treatment works 

PPCP .....................................Pharmaceuticals and personal care product 

ppt..........................................Part(s) per thousand 

PSU........................................Practical salinity unit 

P:T .........................................Power to tonnage ratio 

QA/QC ..................................Quality assurance/quality control 

QAPP.....................................Quality Assurance Project Plan 

QCW......................................Quality Criteria for Water 

A-3 
Appendix A – List of Acronyms 

RIB ........................................Rigid inflatable boat

RL..........................................Reporting limit 

RPD .......................................Relative percent difference 

RPM ......................................Rotations per minute 

RSW ......................................Refrigerated seawater 

SCCWRP ..............................Southern California Coastal Water Research Project 

SDRWQCB...........................San Diego Regional Water Quality Control Board 

SGT-HEM.............................Silica Gel Treated n-hexane extractable materials 

SH ..........................................Shellfish harvesting 

SIYB ......................................Shelter Island Yacht Basin 

SWRCB.................................State Water Resources Control Board 

SSO........................................Sanitary sewer overflow 

SVOC ....................................Semivolatile organic compound 

SW .........................................Salt water 

TBT........................................Tributyltin 

TIC ........................................Tentatively identified compound 

TIE.........................................Toxicity identification and evaluation 

TKN.......................................Total Kjeldahl Nitrogen 

TMDL....................................Total maximum daily load

TOC.......................................Total organic carbon 

TP ..........................................Total phosphorus 

TRC .......................................Total residual chlorine 

TSS ........................................Total suspended solids 

UK..........................................United Kingdom 

UNDS.....................................Uniform National Discharge Standards 

U.S. ........................................United States 

U.S.C......................................United States Code 

USCG ....................................United States Coast Guard 

USGS .....................................United States Geological Survey 

VGP .......................................Vessel General Permit 

VESDOC...............................Merchant Vessels of the United States 

A-4 
Appendix A – List of Acronyms 

A-5 

VOC.......................................Volatile organic compound 

W+O ......................................Water Quality Criteria for Human Health based on Water 

and Organism Consumption 

WHO .....................................World Health Organization 

WHOI....................................Woods Hole Oceanographic Institute 

WOD05..................................World Ocean Database 2005 

WTLUS .................................Waterborne Transportation Lines of the United States 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Appendix B 

Additional Characteristics of the P.L. 110 – 299 Vessel Population 

This appendix provides additional details regarding study vessels. These details include 

additional information on vessel subcategories, general information about vessels’ areas of operation 

(based upon their hailing port), and additional details regarding vessels’ age and areas of operation. The 

discussion is based on data from the 139,814 vessels in the MISLE database identified as being within 

the study vessel population. These data have limitations as discussed in section B.6. 

B.1 Vessel Subcategories 

Table B.1 presents the top five subcategories by each general vessel service to provide insight 

into the various types of vessels included the categories. Except for utility vessels (for which the top five 

vessel classes are listed), vessel types are displayed for all other vessel service categories. Vessel class 

generally relates to the vessel construction or design whereas the type is a more detailed explanation of 

the vessels purpose and capabilities.1 As shown in Table B.1, fish catching vessels – which are the focus 

of the definition of commercial fishing vessels included by reference in P.L. 110-299 – account for the 

vast majority of commercial fishing vessels recorded in MISLE. 

Table B.1: Top Five Vessel Subcategories by Vessel Serviceab

Vessel Service Vessel Type/Classc Number of Vessels 

Fish Catching Vessel 68,343 

Fishing Catching/Processing Vessel 178 

General 174 

Motor Propelled Vessels 155 

Commercial Fishing Vessel 

Fishing Support Vessel 116 

Other non-recreational vessels (less than 79 feet in length)

General 6,954 

Dry Cargo Barge 411 

Deck Barge 295 

Lash / Seabee Barge 36 

Freight Barge 

Container Barge 8 

General 533 

Fishing Support Vessel 23 

Fish Catching Vessel 21 

Container Ship 14 

Freight Ship 

Ro-Ro/Container 4 

General 12,559 

Charter Fishing Vessel 2,053 

Excursion/Tour Vessel 1,233 

Diving Vessel (Recreational) 305 

Passenger Vessel 

Water Taxi 298 

 

1

 In addition, although not shown in Table B.1, a more detailed category exists in the database, vessel subtype. This field 

further breaks out the vessel types. For example, subtype fields that exist for fish catching vessels include trawlers, 

shrimpers, and whalers. 

B-1 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Vessel Service Vessel Type/Classc Number of Vessels 

General 145 

Law Enforcement (Non-military) Vessel 47 

Buoy/Lighthouse Tender 16 

Search and Rescue Vessel 14 

Public Vessel, Unclassified 

Patrol Ship 10 

Bulk Liquid Cargo (Tank) Barge 838 

Bulk Liquefied Gas Barge 10 

Dry Cargo Barge 7 

General 7 

Tank Barge 

Integrated Tug and Barge (Barge) 4 

General 102 

Petroleum Oil Tank Ship 22 

Gas Carrier 20 

Chemical Tank Ship 14 

Tank Ship 

Bulk Liquid Cargo (Tank) Barge 1 

Towing Vessel 7,372 

Offshore 650 

Research Ship 488 

Barge 396 

Utility Vessel 

School Ship 60 

a This table is based on operational, U.S. flagged commercial fishing vessels (all lengths) and other non-recreational vessel less 

than 79 feet, including vessels that have an unspecified length (zero or null). 

b “Unspecified” or “Miscellaneous Vessel” subcategories were not included among the top five vessel subcategories. 

c Vessel types are displayed for all vessel service categories except for utility vessels; the top five vessel classes are listed for 

utility vessels. 

Source:U.S. Coast Guard MISLE database, 2009 

B.1.1 Population of Vessels undergoing Discharge Analysis 

Table B.2 summarizes the population of specific vessel sub-types that were investigated and 

sampled by EPA: commercial fishing vessels, water taxis/ferries, tour vessels, towing vessels, 

emergency boats, and vessels classified as recreational vessels that operate as non-recreational vessels2

. 

The vessel counts presented in the table provide rough estimates of the number of vessels that may be 

represented by each category of sampled vessels.3

 

EPA generally used the vessel service or current usage to categorize study vessels, however, the 

MISLE vessel classification generally refers to the category of vessel based on its original construction. 

The MISLE vessel type field provides the more detailed explanation of the vessels’ purpose and current 

use. A more detailed vessel subtype category also exists in the MISLE database to further break out the 

vessel types. For example, MISLE has subtype entries for trawlers, shrimpers, and whalers within the 

fish catching vessel type, allowing for the population of vessels within these specific subtypes to be 

estimated. 

 

2

 EPA discusses the vessels sampled for this report in greater detail in Chapter 2 of this report. 

3

 EPA considers these estimates to be only approximate counts due to the potential misclassification of vessels in MISLE as 

well as some of the dataset’s ambiguous vessel classifications (e.g. categorizing a vessel as “general”). 

B-2 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

B-3 

Table B.2: Total Number of Vessels in a Given Subtype which EPA Subsampled 

Vessel 

Service Vessel Type 

Number of 

Vesselsa

Percent of Vessel 

Type within Vessel 

Service 

Commercial Fishing Vessel 69,944 100.0% 

 

All Commercial Fishing 

Vessel 69,944 100.0% 

Passenger Vesselsb 20,953 100.0% 

 Water Taxi 298 1.4% 

Ferry 272 1.3% 

Excursion/Tour Vessel 1,233 5.9% 

Utility Vessel 11,034 100.0% 

 

Towing Vessel (includes 

Tugboats) 7,751 70.2% 

Non-Recreational Vessel 69,870 100.0% 

 

Classified as Recreational 

(on the basis of vessel type) 1,624 2.3% 

a Number of vessels accounts for all vessels less than 79 feet in length, including vessels of unspecified length (zero 

or null) 

b Most passenger vessels are listed as “general” passenger vessels: out of the approximately 21,000 passenger 

vessels, nearly 13,000 are listed as “general” passenger vessels.

Source: U. S. Coast Guard, MISLE database, 2009

In addition to the specific vessel types listed above, EPA sampled recreational vessels used in 

non-recreational service, in part to determine whether characteristics of their discharges differ from 

those of other types of vessels used in similar applications. The Clean Boating Act of 2008 covers 

vessels manufactured for recreational uses, unless they are inspected vessels used commercially. 

Table B.3 provides examples of the most common vessels classified as recreational vessels in 

MISLE but that are identified as operating in a non-recreational capacity. Because the analysis presented 

throughout this section generally defines the population of moratorium vessels on the basis of the vessel 

service rather than original manufacture purpose, the vessel population estimate of generated for this 

report may overestimates the number of vessels to which the moratorium in P.L. 110-299 applies. Most 

vessels manufactured primarily for pleasure are permanently excluded from NPDES requirements by the 

Clean Boating Act4

 rather than the shorter-term moratorium in P.L. 110-299 as long those vessels meet 

the definition of a recreational vessel under the Clean Boating Act.

 

4

 The Clean Boating Act, P.L. 110-288 defines the term ‘recreational vessel’ to mean any vessel that is— ‘‘(i) manufactured 

or used primarily for pleasure; or (ii) leased, rented, or chartered to a person for the pleasure of that person.” However, the 

term recreational vessel excludes any vessel “that is subject to Coast Guard inspection and that is (i) engaged in commercial

use or (ii) carries paying passengers.”. 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Table B.3: Examples of Study Vessels in a Non-Recreational Vessel Service, Classified as 

Recreational Vessels 

Vessel Class Vessel Service Vessel Type Number of Vessels 

Recreational Passenger Vessel Passenger (Uninspected) 767 

Recreational 

Commercial Fishing 

Vessel 

Commercial Fishing 

Vessel 232 

Recreational Utility Vessel Research Vessel 22 

Source: U. S. Coast Guard, MISLE database, 2009

B.2 Vessel Geographical Area of Operation 

EPA used MISLE data on hailing port of individual vessel records to characterize the 

geographical area of operation of vessels in the selected population. Although the hailing port does not 

account for the detailed traffic patterns of a vessel or for the amount of time a given vessel spends in the 

listed port, it nevertheless can provide information on a vessel’s general area of operation. This may be 

particularly true of vessels that may have a fairly limited range of operation by virtue of their smaller 

size or the nature of activities they engage in (e.g., tug boat that operates within a given port area). Out 

of the 139,814 vessels in the study vessel population, 76,956 MISLE vessel records had sufficiently 

detailed information to determine their hailing state and general region of operation.5 

Of the approximately 77,000 vessels records having sufficiently detailed information to 

determine their state and general region of operation, 20,000 vessels provided one of the hailing ports 

listed in Figure B.1. As evidenced by the figure, certain port cities, such as Seattle, WA and Juneau, AK 

are predominantly commercial fishing centers, while New Orleans, LA and New York, NY are 

predominantly listed by other non-recreational vessels. New Orleans, LA, is the most frequently cited 

hailing port with approximately 1,300 commercial fishing vessels and 3,800 other non-recreational 

vessels less than 79 feet. These hailing port distributions were used to inform estimates of vessels in a 

given water body for EPA’s screening level modeling in Chapter 4 of this report. 

 

5

 For the remaining vessels, the hailing port information was either missing or too incomplete to be used in the 

analysis (e.g., only city name is provided). 

B-4 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Figure B.1: Approximate Number of Study Vessels for Hailing Ports Frequently Cited in MISLE 

 

0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000

New Orleans, LA

Seattle, WA

New York, NY

Houston, TX

San Francisco, CA

Juneau, AK

Miami, FL

Norfolk, VA

Boston, MA

Houma, LA

Cordova, AK

Homer, AK

Sitka, AK

Kodiak, AK

San Diego, CA

Portland, OR

Key West, FL

Ketchikan, AK

Gloucester, MA

Petersburg, AK

Hailing Port

Approximate Number of Vessels

Commercial Fishing Vessel

Other Non-Recreational Vessel

Note: This table is based on 76,956 operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet for which 

hailing port information is provided in MISLE. EPA notes that the hailing port information is only available for about half of the “study vessels” listed in 

the MISLE database. 

Source: U. S. Coast Guard, MISLE database, 2009

Table B.4 presents the number of vessels by vessel service and the nine census divisions, as 

displayed in Figure B.2 below.6

 The divisions are defined by the U.S. Census Bureau as standard 

geographical units for reporting data for aggregated states. Although not specifically designed for this 

purpose, the divisions tend to follow the major maritime trade axes and waterways (e.g., coastwise, 

inland, Great Lakes, Pacific and Atlantic Oceans, Mississippi River, Gulf of Mexico) and therefore 

provide useful groupings for reporting vessel population estimates. The majority of approximately 

70,000 vessels within the scope of P.L. 110-299 for which MISLE provides a U.S. hailing port operate 

within the Pacific and South Atlantic divisions (28 and 25 percent of vessels, respectively). This 

regional distribution is driven in part by the large concentration of commercial fishing vessels in the two 

regions primarily in Alaska with 6,560 vessels and Florida with 3,804 vessels. 

 

6

 In addition, separate vessel counts are provided for U.S. territories (Puerto Rico, US Virgin Islands, American Samoa, and 

Guam), Canadian provinces (Newfoundland and Labrador, New Brunswick, Quebec, Nova Scotia, Ontario, Alberta, and 

British Columbia), and for vessels that listed either another foreign hailing port or did not list a hailing port. 

B-5 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Table B.4: Number of Study Vessels by Vessel Service and Census Division, based on Hailing Port 

Information Provided in MISLE. 

Census 

Division 

Commercial 

Fishing 

Vessel 

Freight 

Barge 

Freight 

Ship 

Passenger 

Vessel 

Public 

Vessel, 

Unclassified 

Tank 

Barge 

Tank 

Ship 

Utility 

Vessel Unspecified

New 

England 7,173 41 39 1,158 14 12 6 302 939 

Middle 

Atlantic 1,585 466 27 1,414 4 8 7 645 1,016 

East North 

Central 414 53 20 1,274 2 28 487 1,467 

West North 

Central 45 181 7 175 4 1 538 172 

South 

Atlantic 9,400 440 83 4,821 15 39 18 1,347 3,062 

East South 

Central 1,606 21 2 378 3 1 479 261 

West South 

Central 6,386 2,238 22 1,107 5 65 4 2,732 924 

Mountain 59 11 1 142 24 81 

Pacific 14,482 129 133 3,187 19 64 5 1,155 2,281 

National 

Total 41,150 3,580 334 13,656 62 221 41 7,709 10,203 

U.S. 

Territories 230 8 1 353 3 8 46 129 

Canadian 

Province 3 2 

Unknown / 

Other 28,561 4,428 433 6,942 557 694 138 3,279 17,043 

This table is based on operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet (including vessels of 

unspecified length) for which MISLE provides sufficiently detailed hailing port information. 

Source: U. S. Coast Guard, MISLE database, 2009 

B-6 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Figure B.2: Geographical Definitions of U.S. Census Divisions 

The geographical distribution of commercial fishing vessels and other non-recreational vessels 

less than 79 feet is illustrated in the maps of Figure B.3 and Figure B.4, respectively. Commercial 

fishing vessels tend to cluster exclusively along the coastlines. Non-recreational vessels less than 79 feet 

tend to be found on the major U.S. shipping waterways such as the Mississippi river and the Great 

Lakes. 

B-7 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Figure B.3: Geographical Distribution of Commercial Fishing Vessels by Hailing Port State 

Source: U. S. Coast Guard, MISLE database, 2009; based on subset of operational, U.S. flagged commercial fishing vessels for which MISLE provides a 

hailing port.

B-8 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Figure B.4: Geographical Distribution of Study Vessels (excluding Commercial Fishing Vessels) by Hailing Port State 

Source: U. S. Coast Guard, MISLE database, 2009; based on subset of operational, U.S. flagged other non-recreational vessels less than 79 feet in length 

(including vessels of unspecified length) for which MISLE provides a hailing port.

Alaska and Florida both report a high number of commercial fishing vessels. These states have 

long coastal shorelines and the vessel density by miles of tidal shorelines is lower than in other states 

such as Mississippi, New Hampshire, and Massachusetts that have comparatively fewer miles of 

shoreline but access to large fishing grounds. According to National Marine Fisheries Service data, for 

example, Massachusetts alone accounted for over half of fish landings recorded in New England states 

in 2007, by pound.7

 Figure B.5 illustrates these differences by showing the density of commercial 

fishing vessels by miles of tidal shorelines. The states represented in Figure B.5 account for 99 percent 

of commercial fishing vessels recorded in MISLE that report a hailing port. 

 

7

 Annual Commercial Landing Statistics database 

(http://www.st.nmfs.noaa.gov/st1/commercial/landings/annual_landings.html), Accessed May 26, 2009. 

B-9 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Figure B.5: Density of Commercial Fishing Vessels in Coastal States, by Mile of Tidal Shoreline 

0.0

0.5

1.0

1.5

2.0

2.5

3.0

ALLA

MS

TX

DC

DE

MD

PAVA

CT

MAME

NH

NJ

NY

RI

AK

CA

HI

OR

WA

FL

GA

NC

SC

Vessel Density 

(Number of Vessels / Mile of Tidal Shoreline)

Commercial Fishing Vessel Density

Gulf Coast Mid Atlantic North Atlantic Pacific South Atlantic

Coastal states included above account for 99 percent of commercial fishing vessels recorded in MISLE, 

Sources: U. S. Coast Guard, MISLE database, 2009; based on subset of operational, U.S. flagged commercial fishing vessels for which MISLE provides a 

U.S. hailing port. Miles of tidal shoreline from U.S. Geological Survey and National Oceanic Atmospheric Administration, National Atlas of the United 

States, Coastline and Shoreline. Miles include shoreline of the outer coast, offshore islands, sounds, and bays, as well as the tidal portion of rivers and 

creeks.

In contrast to commercial fishing vessels, which are found almost exclusively along U.S. coasts, 

about a third of other non-recreational vessels less than 79 feet in length for which MISLE provides 

hailing port information have a hailing port located along inland waterways. Figure B.6 shows the 

density of these vessels by state, based on inland water area. Several inland and Great Lakes states (e.g., 

Missouri, Indiana, and Kentucky) exhibit a high vessel density in relation to their inland water areas, 

reflecting these states’ adjacency to key navigable waterways such as the Mississippi or Missouri 

Rivers. However, though a vessel lists a city or state as its hailing port, it is unlikely that all vessel 

operations are confined exclusively to those states waters for many vessels. Additionally, as most vessel 

traffic may take place on only a small set of navigable waterways, vessel density in these navigable 

waters is likely to be even greater than implied by the state-wide numbers shown in Figure B.6. Hence, 

these are relative densities which likely depict which state waters have higher vessel activity. 

B-10 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

B-11 

Figure B.6: Density Study Vessels (excluding Commercial Fishing Vessels) by State, by Water Area 

0

2

4

6

8

10

12

14

16

IL

IN

MI

MN

OH

WI

ALLA

MS

TX

AR

AZ

CO

IA

ID

KSKY

MO

MTND

NE

NM

NV

OK

SD

TNUT

VT

WVWY

DC

DE

MD

PAVA

CT

MAME

NH

NJ

NY

RI

AK

CA

HI

OR

WA

FL

GA

NC

SC

Vessel Density 

(Number of vessels / square mile of inland water)

Other non-Recreational Vessel

Density (per water area)

Great Lakes Gulf Coast Inland Mid Atlantic N Atlantic Pacific S Atlantic

Sources: U. S. Coast Guard, MISLE database, 2009; based on subset of operational, U.S. flagged other non-recreational vessels less than 79 feet in length 

(including vessels of unspecified length) for which MISLE provides a U.S. hailing port. State statistics on square miles of water obtained from U.S. Census, 

Statistical Abstract of the United States, 2008. The area includes inland, coastal, Great Lakes, and territorial waters. 

B.3 Other Vessel Characteristics: Construction and Propulsion 

This section presents information on other various characteristics of study vessels that not only 

influence how vessels are used (e.g., for towing or icebreaking purposes vs. lighter service), but may 

also affect the characteristics of discharges incidental to vessel operations. In particular, the section 

provides statistics on the age of the vessels (Section B.3.1), hull material (Section B.3.2), propulsion 

method and fuel type (Section B.3.3), and, for self-propelled vessels, engine power rating (Section 

B.3.4). As for other vessel statistics presented in this report, the data are obtained from the USCG’s 

MISLE database. 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

B.3.1 Vessel Age 

Figure B.7 and Figure B.8 present the distribution of study vessels by vessel construction date or 

age. Figure B.7 summarizes the information across the entire selected population whereas details for 

each vessel service category are provided in Figure B.8. As seen from both figures, nearly half of the 

vessels fall within the age range of 25 to 50 years. The average age of vessels across all service 

categories is 33 years. 

Vessel age is one of the factors that generally determines the type and performance of equipment 

used onboard vessels and the characteristics of discharges from the equipment. However, EPA 

recognizes that older vessels often have equipment which is rebuilt or replaced. For example, if an older 

vessel replaces its engine, the engine effluent will be influenced by the type and performance of the 

engine, not by the vessel’s age. Freight ships and tank ships tend to have been in service longer than 

passenger vessels and generally have a greater level of rebuilding and replacement of original 

equipment. 

Figure B.7: Distribution of Study Vessels by Age, in Years 

Less than 5 years

9.9%

10-25 years

23.6%

25-50 years

48.6%

50-100 years

17.7%

100 or more years

0.3%

Note: This table is based on operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet (including vessels of 

unspecified length). 

Vessel age was either not reported or an invalid age (i.e. less than zero) was reported for approximately 43,000 vessels. 

Source: U. S. Coast Guard, MISLE database, 2009 

B-12 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Figure B.8: Distribution of Study Vessels by Age and Vessel Service 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

100 or more years 256 146 2 7 36 50 15

50-100 years 17,231 10,921 173 305 2,669 81 19 2,246 817

25-50 years 47,208 26,715 3,514 144 7,954 31 102 25 4,111 4,612

10-25 years 22,892 11,049 290 35 4,525 10 84 1,148 5,751

Less than 5 years 9,603 3,125 321 19 2,502 13 50 5 920 2,648

All Vessels

Commercial 

Fishing 

Vessel

Freight Barge Freight Ship Passenger 

Vessel

Public 

Vessel, 

Unclassified

Tank Barge Tank Ship Utility Vessel Unspecified

Note: This table is based on operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet (including vessels of 

unspecified length). 

Vessel age was either not reported or an invalid age (i.e. less than zero) was reported for approximately 43,000 vessels. 

Source: U. S. Coast Guard, MISLE database, 2009 

B.3.2 Hull Material Type 

Figure B.9 and Figure B.10 present the distribution of vessels by type of hull material type. 

Figure B.9 provides a summary across all vessel service categories whereas Figure B.10 presents the 

information disaggregated by each category of vessel service. 

The three most common hull material types are fiberglass, wood, and steel in order of most 

common usage. Commercial fishing vessels with wood hulls account for over three quarters of the total 

number of wood hulled vessels, although wood is also used in the hulls of a significant share of freight 

ships and passenger vessels less than 79 feet in length. The type of hull material affects the type of antifoulant coatings that are applied and has implications on vessel discharges and receiving water quality. 

For example, steel hulls often have an anti-corrosive as well as anti-foulant hull coatings. The type of 

B-13 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

hull material may also affect the frequency with which certain maintenance procedures such as hull 

inspections are conducted. 

Figure B.9: Number of Study Vessels by Hull Material Type 

Aluminum

6.9%

Concrete

0.2%

Fiberglass

35.6%

Steel

24.2%

Wood

29.1%

Plastic: MSIS Legacy

3.4%

Glass

0.5%

Rubber

0.04%

Plastic: Non-Reinforced

0.1%

Note: This table is based on operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet (including vessels of 

unspecified length). 

Hull material type was not reported for approximately 43,000 vessels. 

Source: U. S. Coast Guard, MISLE database, 2009 

B-14 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Figure B.10: Distribution of Study Vessels by Hull Material and Vessel Service 

0%

20%

40%

60%

80%

100%

Wood 28,226 21,474 87 285 5,002 1 2 6 510 859

Steel 23,524 7,805 4,391 224 1,633 25 323 43 7,082 1,998

Rubber 34 1 10 2 21

Plastic: Non-Reinforced 98 58 2 2 36

Plastic: MSIS Legacy 3,318 1,875 22 9 684 1 10 717

Glass 463 310 1 33 16 103

Fiberglass 34,536 19,433 20 38 8,022 16 4 408 6,595

Concrete 213 137 2 2 36 1 35

Aluminum 6,704 2,211 15 36 2,698 15 4 8 778 939

All Vessels

Commercial 

Fishing 

Vessel

Freight 

Barge Freight Ship Passenger Vessel

Public 

Vessel, 

Unclassified

Tank Barge Tank Ship Utility Vessel Unspecified

Note: This table is based on operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet (including vessels of 

unspecified length). 

Approximately 43,000 vessels reported in MISLE do not have a hull material or have a material other than the primary materials listed above. 

Source: U. S. Coast Guard, MISLE database, 2009 

B.3.3 Propulsion Method and Type 

Figure B.11 presents the number and percentage of vessels by vessel service and propulsion 

method. A vessel is characterized as self-propelled if the vessel uses self-contained engines and other 

machinery to propel the vessel (wind-driven vessels are also included in this category). Non-self 

propelled vessels are generally propelled by a separate towing vessel e.g. a barge or mobile offshore 

drilling unit is propelled by a tugboat. 

Overall, within the selected subset of the study vessel population for which data are available in 

MISLE, 70 percent of vessels are self-propelled. The fraction of self-propelled vessels by service type 

varies from a low of 4 to 5 percent for freight barges and tank barges, to approximately 80 percent for 

commercial fishing vessels, freight ships, passenger vessels, and utility vessels. Most self-propelled 

vessels recorded in MISLE are propelled by either diesel motors (66.5 percent) or gasoline motors (26.9 

percent). 

B-15 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Self-propelled vessels that use mechanical propulsion methods have certain types of equipment 

such as an engine, propeller shaft, and propulsion fuel tanks, which would affect the characteristics of 

discharges under normal operations. Discharges from these vessels may be more likely to have higher 

concentrations of oil, grease, organic compounds, and metals due to their use of lubricants, fuels and 

machinery. 

Figure B.11: Distribution of Study Vessels by Propulsion Method 

15,686

7,696

158

3,892

499

875

94

2,336

10,983

54,258

610

123

48

85

8,698

320

17,061

16,392

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Commercial Fishing Vessel

Freight Barge

Freight Ship

Passenger Vessel

Public Vessel, Unclassified

Tank Barge

Tank Ship

Utility Vessel

Unspecified

Vessel Service

Percent of Vessels

Self-Propelled

Non Self-Propelled

Note: This table is based on operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet (including vessels of 

unspecified length). 

Source: U. S. Coast Guard, MISLE database, 2009

B.3.4 Horsepower Ahead 

Figure B.12 and Figure B.13 display the distribution of study vessels by horsepower ahead. 

Horsepower ahead represents the rated power of a vessel’s engine in forward motion (as opposed to 

horsepower astern) and is expressed as the work accomplished per unit of time (e.g., 1 hp = 550 footpounds of work per second). This power is transferred to the propulsion mode (e.g., jet or propeller) to 

create thrust and determines the vessel’s speed at any given weight, or the weight that can be moved at 

any given speed. Figure B.12 summarizes the information across all vessels within the selected 

population whereas Figure B.13 presents the information by vessel service category. Vessel power 

B-16 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

rating may determine the amount and characteristics of discharges from operating vessels by affecting 

the size, type, and complexity of onboard propulsion equipment. 

As evidenced by the two figures, nearly 62 percent of all vessels have a horsepower ahead 

ranging between 100 and 500. The average value across all vessels is 411 horsepower. The utility vessel 

and public vessel service categories have the highest proportion of vessels with a horsepower rating of 

1,000 or greater. This is expected given the type of activities conducted by vessels in these service 

categories, e.g., towing and ice breaking. While not reflected in the figure, the MISLE data suggests a 

general relationship between vessel size and horsepower rating, within a given category of vessels.

Figure B.12: Distribution of Study Vessels by Horsepower Ahead 

Less than 100 

horsepower

12.2%

100-500 horsepower

61.8%

500-1,000 horsepower

18.8%

1,000-5,000 

horsepower

7.1%

5,000 or more 

horsepower

0.1%

Note: This table is based on operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet (including vessels of 

unspecified length). 

MISLE does not report horsepower ahead for approximately 114,000 non-recreational study vessels. 

Source: U. S. Coast Guard, MISLE database, 2009 

B-17 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Figure B.13: Distribution of Study vessels by Horsepower Ahead and Vessel Service 

0%

20%

40%

60%

80%

100%

5,000 or more horsepower 28 21 2 1 2 2

1,000-5,000 horsepower 1,831 443 1 5 642 1 1 711 27

500-1,000 horsepower 4,886 1,732 4 16 1,808 2 6 2 1,174 142

100-500 horsepower 16,041 8,748 13 54 4,473 4 1 19 1,159 1,570

Less than 100 horsepower 3,167 1,364 4 9 1,059 2 2 10 111 606

All Vessels

Commercial 

Fishing 

Vessel

Freight Barge Freight Ship Passenger 

Vessel

Public 

Vessel, 

Unclassified

Tank Barge Tank Ship Utility Vessel Unspecified

Note: This table is based on operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet (including vessels of 

unspecified length). 

Approximately 114,000 vessels reported in MISLE have no horsepower ahead value or a value of zero. 

Source: U. S. Coast Guard, MISLE database, 2009 

B.4 Distribution of the Study Vessel Universe versus the Recreational Vessel Universe 

While the analysis presented in this section generally focuses on the subset of study vessels, a 

comparison of those vessels to the overall population is pertinent to understanding how discharges may 

differ between these vessels. At the same time, comparison of estimates provided in different sources 

also helps verify the population estimate derived from MISLE data. As discussed later in this section, 

the MISLE database appears to provide reasonably accurate data for larger recreational vessels; 

however, the database does not appear to provide accurate information for recreational vessels less than 

25 feet. 

A comparison of the geographical distribution of the selected vessel population to that of the 

overall MISLE vessel universe (including all operational, U.S. flagged vessels) highlights some key 

B-18 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

differences. As discussed below in this section, recreational vessels less than 25 feet are not well 

represented in MLSE; hence, the values presented in these tables do not accurately reflect vessel 

numbers of these smaller vessels. As reflected in Figure B.14 below, several states that have hailing 

ports with a high percentage of the study vessel population account for a comparatively low percentage 

of the total universe of vessels. Conversely, States, such as California, with the largest number of vessels 

overall have comparatively fewer vessels in the population of commercial fishing vessels and nonrecreational vessels less than 79 feet. The difference is generally attributable to the geographical 

distribution of recreational vessels (Figure B.15) as larger recreational vessels tend to be concentrated in 

certain states due to the states’ longer coastlines, higher population or income, and/or a longer boating 

season. For these states, one can expect considerably greater numbers of recreational versus nonrecreational vessels. The relative shares of non-recreational and recreation vessel categories are 

illustrated in Figure B.16 which summarizes the overall vessel universe by state and vessel service 

category, based on information provided in MISLE. 

Figure B.14: Geographical Distribution of MISLE Vessel Universe by Hailing Port State 

Source: U. S. Coast Guard, MISLE database, 2009; based on operational, U.S. flagged vessels for which MISLE provides a hailing port. Note that MLSE 

does not provide accurate estimates for smaller recreational vessels. 

B-19 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

B-20 

Figure B.15: Geographical Distribution of Recreational Vessels by Hailing Port State 

Source: U. S. Coast Guard, MISLE database, 2009. Note that MLSE does not provide accurate estimates for smaller recreational vessels. 
Appendix B – Additional Characteristi

Figure B.16 Comparison of the Number of MLSE recorded (Larger) Recreational vessels to Study Vessels by 

0

10,00020,00030,00040,00050,00060,00070,00080,00090,000

AK

AL

AR

AZ

CA

CO

CT

DC

DE

FL

GA

HI

IA

ID

IL

IN

KS

KY

LA

MA

MD

ME

MI

MN

MO

MS

MT

NC

ND

NE

NH

NJ

NM

NV

NY

OH

OK

OR

PA

RI

SC

SD

TN

TX

UT

State

Number of Vessels

Recreational VesseCommercial Fishing Other Non-Recreati

Note: The hailing port state was either not listed or a foreign port was listed for approximately 285,000 and 6,000 vessels, respectively. All vessels are included within each oregardless of length. The data likely only includes larger recreational vessels captured in MISLE and is therefore a gross underestimate of the total population of recreational vessels. Source: U. S. Coast Guard, MISLE database, 2009 

B-21 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Study vessels represent a very small share of the total number of vessels operating on U.S. 

waters is evidenced by comparisons of the estimated number of study vessels (139,814 vessels) to the 

national statistics on recreational vessels. While the number of recreational vessels reported in MISLE is 

large (700,000 vessels), the actual number of recreational vessels found on U.S. waters is known to be 

significantly greater, or about 17 million. This is because industry estimates indicate a much larger 

number of recreational vessels than are captured in MISLE, particularly for smaller vessels less than 

26 feet. 

In its 2008 Recreational Boating Statistical Abstract, the National Marine Manufacturers 

Association (NMMA) estimates that there are approximately 16.9 million recreational vessels in the 

U.S., including 13 million registered and/or documented boats and more than 4 million non-registered 

boats. This is a significantly greater estimate than the number of vessels documented in MISLE, which 

records the characteristics of 722,522 recreational vessels. The difference is accounted for by stateregistered vessels that are not subject to documentation requirements8

, hence, they are captured by 

NMMA but not by MLSE. Figure B.17 illustrates the distribution of vessels by service and length, this 

time including additional recreational vessels captured in industry estimates (NMMA, 2009). Figure 

B.18 compares recreational vessels reported by MLSE and NMMA across the various census regions are 

covered in MISLE. As shown in these figures, there are a significantly greater number of small 

recreational vessels (less than 26 feet in length) than suggested by MISLE data alone. While MISLE 

grossly underestimates the number of recreational vessels below 26 feet, it appears to provide more 

reliable estimates for larger recreational vessel (MISLE over-represents the number of recreational 

vessels in the 40 to 65 feet length category, while it accounts for 55 percent and 73 percent of 

recreational vessels recorded by NMMA in the 26 to 40 feet and greater than 65 feet categories, 

respectively). Across all size categories with the exception of vessels greater than 65 feet, nonrecreational vessels account for a relatively small fraction of the total universe of domestic vessels 

operating in U.S. waters.

 

8

 Additional state boating regulations require that non-documented vessels, including smaller recreational vessels less than 

five tons, register with state authorities. While vessel registration requirements under State boating regulations vary, many 

states require that vessels of any size equipped with primary or secondary propulsion be registered; in some cases, nonmotored vessels above 15 feet in length must also be registered. See additional discussion under Section B.5. 

B-22 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

B-23 

Figure B.17: Distribution of Vessels by Service Category and Length (in feet), Accounting for MISLE AND NMMA 

Estimates of Recreational Vessels 

47,045

34,598

65,146

306,214

95,754

8,206

5,063,722 5,999,044

249,494

3,038

1,052 12,509

34,915 234,082

-27,842

-20%

0%

20%

40%

60%

80%

100%

< 16 16 - 26 26 - 40 40-65 > 65

Vessel Length (in feet)

Number of Vessels

NMMA Additional Recreational Vessels

MISLE Recreational Vessels

MISLE Non-recreational Vessels

Source: U. S. Coast Guard, MISLE database, 2009 and NMMA 2007 Recreational Boating Statistical Abstract. 

An additional 43,351 vessels are included in MISLE but do not have length information. These vessels are therefore excluded from the figure. 
Appendix B – Additional Characteristi

Figure B.18: Recreational Vessels as Reported in MISLE and as Estimated by NMMA 

0

500,000

1,000,0001,500,0002,000,0002,500,000

New England

Middle Atlantic

East North Central

West North Central

South Atlantic

East South Central

West South Central

Mountain

Pacific

New England

Middle Atlantic

East North Central

West North Central

South Atlantic

East South Central

West South Central

Mountain

Pacific

New England

Middle Atlantic

East North Central

West North Central

South Atlantic

Census Division

Number of Vessels

MN

Less than 26 ft 26 - 65 ft 65 ft or g

0

500

1,0001,5002,0002,5003,0003,500

New

England

Middle

Atlantic

East

North

Central

West

North

Central

South

Atlantic

East

South

Central

West

South

Centra

Yellow bars represent NMMA data while blue bars represent MISLE data Source: U. S. Coast Guard, MISLE database, 2009 and NMMA 2007 Recreational Boating Statistical Abstract

B-24 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

B.5 Vessels Documented, Inspected, and/or State Registered 

The MISLE database classifies vessels as documented, inspected, and/or state registered. These 

classifications are used to identify the types of requirements to which a given vessel is subject. 

According to a Coast Guard representative, generally only vessels that are not documented at the 

national level are state registered.9 On the other hand, based on the MISLE dataset, nearly all (4,982) of 

the 5,259 inspected vessels are also either documented or state registered. 

In order to be classified as a documented vessel, the vessel “must measure at least five tons and, 

with the exception of certain oil spill response vessels, must be wholly owned by a citizen of the U.S.”10

According to a Coast Guard representative, “documentation provides conclusive evidence of nationality 

for international purposes, provides for unhindered commerce between the states, and admits vessels to 

certain restricted trades, such as coastwise trade and the fisheries.” 

A vessel is listed as inspected in MISLE when the vessel is subject to inspection requirements 

under one of several U.S. Coast Guard regulations. According to a Coast Guard representative, certain 

U.S. vessels (e.g. passenger vessels that meet threshold size and passenger requirements) are required to 

undergo safety and security inspections, which includes inspections on a vessel’s machinery, hull, safety 

equipment, and proper documents, before they can operate commercially in U.S. waters.11 

A vessel is listed as state registered when the vessel is registered by a state authority. Only 

vessels that are not documented at the national level are state registered. Although each state sets its own 

registration requirements and therefore these requirements can vary from state to state, generally, any 

undocumented vessel that is self-propelled (meaning that machinery is used to propel the vessel) must 

be registered with the state. 

Table B.5, below, presents the number of study vessels – by vessel service – classified as 

documented, inspected or state registered in MISLE. As seen within Table B.5, overall, approximately 

36 percent of vessels reporting in MISLE are documented, 4 percent of vessels are inspected, and 

26 percent of vessels are state registered, although the fractions of vessels in each class varies across the 

vessel service categories. 

 

9

 Approximately 1,200 vessels are listed as both documented and state-registered. 10 Source: Personal email communication with Harold Krevait of the U.S. Coast Guard. April 22, 2009. Note, however that 

fishing vessels with only a “registry” endorsement on their certification of documentation do not have to be wholly owned by 

U.S. citizens but may be under majority control by U.S. interest (Personal communication with Division Chief, Fishing 

Vessel Safety Division (CG-5433), Fishing Vessel Safety Program, May 26, 2009). 

11 Source: Personal email communication with Harold Krevait of the U.S. Coast Guard. April 22, 2009. 

B-25 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Table B.5: Number of Study Vessels Documented, Inspected, and State Registered, by Vessel 

Service 

Total(1) Documented(2) Inspected(2) State Registered 

Vessel Service Number Number 

Percent of 

Total Number 

Percent of 

Total Number 

Percent of 

Total 

Commercial Fishing Vessel 69,944(3) 27,770(3) 39.7% 3 0.0% 22,438(1) 32.1%

Freight Barge 8,016 811 10.1% 1 0.0% 48 0.6%

Freight Ship 768 211 27.5% 14 1.8% 40 5.2%

Passenger Vessel 20,953 10,613(4) 50.7% 4,968 23.7% 4,044 19.3%

Public Vessel, Unclassified 622 22 3.5% 3 0.5% 21 3.4%

Tank Barge 923 116 12.6% 49 5.3% 10 1.1%

Tank Ship 179 24 13.4% 15 8.4% 8 4.5%

Utility Vessel 11,034 6,008 54.4% 199 1.8% 1,020 9.2%

Unspecified 27,375 4,183 15.3% 7 0.0% 9,030 33.0%

All Vessels 139,814 49,758 35.6% 5,259 3.8% 36,659 26.2%

Note: This table is based on operational, U.S. flagged commercial fishing vessels and other non-recreational vessel less than 79 feet. 

Source: U. S. Coast Guard, MISLE database, 2009 

(1) Total number of other non-recreational vessels (other than commercial fishing vessels) includes all vessels less than 79 feet in 

length and vessels of unspecified length (zero or null). 

(2) “Documented” and “Inspected” are not mutually exclusive categories. The number of documented vessel includes inspected 

vessels. 

(3) The U.S. Coast Guard’s Fishing Vessel Safety Program generally uses a figure of 80,000 as the approximate number of 

commercial fishing vessels, including about 20,000 documented vessels and 60,000 state-registered vessels. In 2007, the states 

reported a total of over 58,000 vessels that fish commercially and are registered in their jurisdictions.12

(4) 3,904 passenger vessels are both documented and inspected. 

As described in Chapter 1, MISLE also includes additional vessels not subject to the 

documentation, inspection, or state registration requirements; information for these vessels was obtained 

through other Coast Guard activities such as non-mandatory inspections or incident investigations. 

B.6 Uncertainty 

The analysis presented in this section draws largely on national-level data collected by the U.S. 

Coast Guard. Several factors contribute to uncertainty in the estimates and findings presented: 

 Scope. Some vessels may not be captured in the database due to the procedures by which 

vessels are identified and entered into the database. Data coverage is believed to be relatively 

good for vessels subject to documentation or inspection requirements (e.g., vessels engaged 

in coastwise trade or passenger vessels), but more incomplete for smaller vessels. The 

absence of information on the smaller, undocumented, uninspected vessels which were not 

manufactured or used for pleasure may lead EPA to under-estimate the size of the study 

vessels population. Conversely, categories used to classify vessels in MISLE may be broader 

than vessels that would otherwise be considered “in scope” for this study; for example, 

passenger vessels may include vessels that would meet the Clean Boating Act definition of 

recreational vessel, depending on their use. 

 

12 Source: Personal communication with Division Chief, Fishing Vessel Safety Division (CG-5433), Fishing Vessel Safety 

Program, May 26, 2009. 

B-26 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

 Completeness. Analyses of vessel characteristics were limited by the information provided 

for a vessel or the manner in which the information is entered. For example, the hailing port 

or horsepower ahead is provided for a only subset of vessels in the database. To the extent 

that the absence of the information is unevenly distributed among the vessel population, 

distributions drawn from the data may provide a biased understanding of the characteristics 

of the vessel population. 

 Accuracy. Even when vessel data are populated, there may be issues with the accuracy of the 

information. For example, the status of vessels no longer operational (i.e., out of service) 

may not have been properly updated or vessel types may be misclassified. These errors are 

difficult to detect and may lead to inaccurate estimates of the actual population. 

Uncertainty related to the scope of the data used in the analysis is discussed in greater detail 

below. Where possible, EPA compared findings drawn from the MISLE data to information from other 

sources, such as NMMA and NOAA, to ascertain and quantify the magnitude of the error on the 

population estimate. This review suggests that MISLE under-represents the population of recreational 

vessels smaller than about 25 feet in length and may similarly under-represent small non-recreational 

vessels. For larger recreational vessels, however, the number of vessels reported in MISLE is close, or 

for some size classes even greater than, the number estimated by NMMA. Based on this comparison, it 

is apparent that MISLE is significantly limited in terms of its characterization of the universe of small 

recreational vessels13. Since the analysis focuses more specifically on non-recreational vessels, however, 

EPA does not consider these limitations to be critical. In general, EPA believes that national vessel 

databases such as MISLE provide adequate coverage for the subset of study vessels, since a significant 

fraction of these vessels can be expected to be larger than about 25 feet in length, and useful data on the 

physical and operational characteristics of the study vessel population. 

While MISLE constitutes the most comprehensive and readily available national-level data sets 

on vessels, it is important to note that the MISLE database covers a subset of vessels that are either 

required to be documented under federal regulations (e.g., at least five net tons) or vessels known to the 

U.S. Coast Guard through vessel inspections or incident investigations. Generally, the five ton tonnage 

threshold means that only those vessels more than about 25 feet in length are covered. 

Unlike recreational vessels, there is no alternate national-level data source that would provide 

recent and comprehensive figures for the number of commercial fishing vessel by size category to allow 

EPA to assess MISLE coverage for these vessels. The MISLE database reports a total of 69,944 

commercial fishing vessels nationally. This number does not include all state-registered vessels that 

commercially fish, but is generally comparable with industry totals reported in other sources. For 

example, Hoovers reports that 25,000 commercial fishing vessels have combined annual revenue of $4 

billion. An additional 55,000 small, undecked vessels are also used to catch wild fish for economic gain, 

though the report notes that industry impact of these undecked vessels is “negligible.” The total number 

of commercial fishing vessels reported in Hoovers would therefore be around 80,000. 14 Additionally, 

the U.S. Coast Guard’s Fishing Vessel Safety Program generally uses a figure of 80,000 as the 

 

13 EPA notes that MISLE is not designed or managed to provide accurate estimates of the small recreational vessel universe. 14 (Source: http://www.hoovers.com/commercial-fishing, accessed 05/01/2009). 

B-27 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

B-28 

 

approximate number of commercial fishing vessels, including about 20,000 documented vessels and 

60,000 state-registered vessels.15 

No separate inventory of other non-recreational vessels less than 79 feet could be found to 

evaluate the coverage of these vessels in MISLE. It is therefore not possible to ascertain the extent to 

which MISLE under represent smaller utility vessels and other non-recreational vessels. 

EPA also compared the number of commercial fishing vessels identified in MISLE with the 

number of vessels holding fishing permit licenses in New England, as obtained from NOAA’s regional 

office, and with separate state-registered vessel estimates provided by the U.S. Coast Guard. Table B.6

presents the count of permitted fishing vessels within NOAA’s New England division permitted vessel 

list and the count of commercial fishing vessels within MISLE that listed a New England hailing state. 

The table also provides estimates of the number of state-registered vessels used in commercial fisheries. 

As seen in the table, the MISLE dataset contains nearly double the number of commercial fishing 

vessels as permitted in NOAA’s New England division. This difference may be due to the slightly 

different scopes of the NOAA and MISLE dataset. NOAA’s dataset only includes permit holders of 

NOAA Fisheries Northeast Region16 2008 Vessel permits, whereas the MISLE dataset includes vessels 

that may not have fishery permits for that year (such as fishing support vessels) in addition to those that 

would hold permits. Additionally, as mentioned in the introduction to this section, it is possible that 

some of the commercial fishing vessels that Coast Guard considers to be operational were not actively 

engaged in fishing activities during 2008. With regards to numbers provided in MISLE as compared to 

state-registered vessel estimates, the MISLE data seem to slightly under-represent the vessels registered 

in New England states. Overall, however, comparison of commercial fishing vessel estimates across 

sources suggests that MISLE may adequately represent the population of these vessels despite the 

vessels’ relatively small size and potentially higher probability of being excluded from the database 

scope.

15Personal communication with Division Chief, Fishing Vessel Safety Division (CG-5433), Fishing Vessel Safety Program, 

May 26, 2009. 

16 Our table specifically compares the New England division data. 
Appendix B – Additional Characteristics of the P.L. 110-299 Population 

Table B.6: Comparison Among NOAA, State-registered and MISLE New 

England Region Commercial Fishing Vessel Populations 

Number of Vessels 

State NOAAa State-registeredb MISLE 

CT 77 256 284 

MA 1,514 2,006 2,492 

ME 1,535 6,508 3,725 

NH 196 0 231 

RI 335 630 438 

VT 0 0 3 

New England 

Total 3,657 9,400 7,173 

a Although NOAA’s Northeast Region Vessel and Permit Listing documents 5,227 vessels, only 

3,657 of these vessels list a principal hailing state in the New England region. 

b. Some of the state registered fishing vessels reported by states for 2007 are also included in the 

reported MISLE numbers.17

Source: National Oceanic and Atmospheric Administration (NOAA) New England Commercial 

Fishing Permit Listing, 2009, U. S. Coast Guard, MISLE database, 2009, and Personal 

Communication with U.S. Coast Guard personnel, May 2009.

 

17 Personal communication with Division Chief, Fishing Vessel Safety Division (CG-5433), Fishing Vessel Safety 

Program, May 26, 2009. 

B-29 
Appendix C – Public Law 110-299 (S. 3298) and Public Law 110-288 (S. 2766) 

Appendix C 

Public Law 110-299 (S. 3298) and Public Law 110-288 (S. 2766) 

Public Law 110-299 (S. 3298) 

One Hundred Tenth Congress 

 of the 

United States of America 

AT THE SECOND SESSION 

Begun and held at the City of Washington on Thursday, 

 the third day of January, two thousand and eight 

An Act 

To clarify the circumstances during which the Administrator of the Environmental Protection Agency and applicable States 

may require permits for discharges from certain vessels, and to require the Administrator to conduct a study of discharges 

incidental to the normal operation of vessels. 

Be it enacted by the Senate and House of Representatives of the United States of America in Congress 

assembled, 

SECTION 1. DEFINITIONS. 

In this Act: 

(1) ADMINISTRATOR.—The term ‘‘Administrator’’ means the Administrator of the Environmental 

Protection Agency. 

(2) COVERED VESSEL.—The term ‘‘covered vessel’’ means a vessel that is— 

(A) less than 79 feet in length; or 

(B) a fishing vessel (as defined in section 2101 of title 46, United States Code), regardless of 

the length of the vessel. 

(3) OTHER TERMS.—The terms ‘‘contiguous zone’’, ‘‘discharge’’, ‘‘ocean’’, and ‘‘State’’ have the meanings 

given the terms in section 502 of the Federal Water Pollution Control Act (33 U.S.C. 1362). 

SEC. 2. DISCHARGES INCIDENTAL TO NORMAL OPERATION OF VESSELS. 

(a) NO PERMIT REQUIREMENT.—Except as provided in subsection (b), during the 2-year period 

beginning on the date of enactment of this Act, the Administrator, or a State in the case of a permit 

program approved under section 402 of the Federal Water Pollution Control Act (33 U.S.C. 1342), 

shall not require a permit under that section for a covered vessel for— 

(1) any discharge of effluent from properly functioning marine engines; 

(2) any discharge of laundry, shower, and galley sink wastes; or 

(3) any other discharge incidental to the normal operation of a covered vessel. 

(b) EXCEPTIONS.—Subsection (a) shall not apply with respect to— 

(1) rubbish, trash, garbage, or other such materials discharged overboard; 

(2) other discharges when the vessel is operating in a capacity other than as a means of 

transportation, such as when— 

(A) used as an energy or mining facility; 

C-1 
Appendix C – Public Law 110-299 (S. 3298) and Public Law 110-288 (S. 2766) 

C-2 

(B) used as a storage facility or a seafood processing facility; 

(C) secured to a storage facility or a seafood processing facility; or 

(D) secured to the bed of the ocean, the contiguous zone, or waters of the United States for 

the purpose of mineral or oil exploration or development; 

(3) any discharge of ballast water; or 

(4) any discharge in a case in which the Administrator or State, as appropriate, determines that 

the discharge— 

(A) contributes to a violation of a water quality standard; or 

(B) poses an unacceptable risk to human health or the environment. 

SEC. 3. STUDY OF DISCHARGES INCIDENTAL TO NORMAL OPERATION OF VESSELS. 

(a) IN GENERAL.—The Administrator, in consultation with the Secretary of the department in which 

the Coast Guard is operating and the heads of other interested Federal agencies, shall conduct a 

study to evaluate the impacts of— 

(1) any discharge of effluent from properly functioning marine engines; 

(2) any discharge of laundry, shower, and galley sink wastes; and 

(3) any other discharge incidental to the normal operation of a vessel. 

(b) SCOPE OF STUDY.—The study under subsection (a) shall include— 

(1) characterizations of the nature, type, and composition of discharges for— 

(A) representative single vessels; and 

(B) each class of vessels; 

(2) determinations of the volumes of those discharges, including average volumes, for— 

(A) representative single vessels; and 

(B) each class of vessels; 

(3) a description of the locations, including the more common locations, of the discharges; 

(4) analyses and findings as to the nature and extent of the potential effects of the discharges, 

including determinations of whether the discharges pose a risk to human health, welfare, or the 

environment, and the nature of those risks; 

(5) determinations of the benefits to human health, welfare, and the environment from reducing, 

eliminating, controlling, or mitigating the discharges; and 

(6) analyses of the extent to which the discharges are currently subject to regulation under 

Federal law or a binding international obligation of the United States. 

(c) EXCLUSION.—In carrying out the study under subsection (a), the Administrator shall exclude— 

(1) discharges from a vessel of the Armed Forces (as defined in section 312(a) of the Federal 

Water Pollution Control Act (33 U.S.C. 1322(a)); 

(2) discharges of sewage (as defined in section 312(a) of the Federal Water Pollution Control Act 

(33 U.S.C. 1322(a)) from a vessel, other than the discharge of graywater from a vessel operating 

on the Great Lakes; and 

(3) discharges of ballast water. 

(d) PUBLIC COMMENT; REPORT.—The Administrator shall— 

(1) publish in the Federal Register for public comment a draft of the study required under 

subsection (a); 

(2) after taking into account any comments received during the public comment period, develop a 

final report with respect to the study; and 

(3) not later than 15 months after the date of enactment of this Act, submit the final report to— 

(A) the Committee on Transportation and Infrastructure of the House of Representatives; 

and 

(B) the Committees on Environment and Public Works and Commerce, Science, and 

Transportation of the Senate. 

Speaker of the House of Representatives. 

Vice President of the United States and President of the Senate. 
Appendix C – Public Law 110-299 (S. 3298) and Public Law 110-288 (S. 2766) 

Public Law 110-288 (S. 2766) 

One Hundred Tenth Congress of the United 

States of America 

AT THE SECOND SESSION

Begun and held at the City of Washington on Thursday, 

the third day of January, two thousand and eight 

An Act 

To amend the Federal Water Pollution Control Act to address certain discharges incidental to the normal operation of a 

recreational vessel. 

Be it enacted by the Senate and House of Representatives of the United States of America in Congress 

assembled, 

SECTION 1. SHORT TITLE. 

This Act may be cited as the ‘‘Clean Boating Act of 2008’’. 

SEC. 2. DISCHARGES INCIDENTAL TO THE NORMAL OPERATION OF RECREATIONAL VESSELS. 

Section 402 of the Federal Water Pollution Control Act (33 

U.S.C. 1342) is amended by adding at the end the following: 

‘‘(r) DISCHARGES INCIDENTAL TO THE NORMAL OPERATION OF RECREATIONAL VESSELS.—No permit shall be 

required under this Act by the Administrator (or a State, in the case of a permit program approved 

under subsection (b)) for the discharge of any graywater, bilge water, cooling water, weather deck 

runoff, oil water separator effluent, or effluent from properly functioning marine engines, or any 

other discharge that is incidental to the normal operation of a vessel, if the discharge is from a 

recreational vessel.’’. 

SEC. 3. DEFINITION. 

Section 502 of the Federal Water Pollution Control Act (33 

U.S.C. 1362) is amended by adding at the end the following: ‘‘(25) RECREATIONAL VESSEL.— ‘‘(A) IN 

GENERAL.—The term ‘recreational vessel’ means any vessel that is— 

‘‘(i) manufactured or used primarily for pleasure; or 

‘‘(ii) leased, rented, or chartered to a person for the pleasure of that person. ‘‘(B) EXCLUSION.—The 

term ‘recreational vessel’ does not include a vessel that is subject to Coast Guard inspection and 

that— ‘‘(i) is engaged in commercial use; or ‘‘(ii) carries paying passengers.’’. 

SEC. 4. MANAGEMENT PRACTICES FOR RECREATIONAL VESSELS. 

Section 312 of the Federal Water Pollution Control Act (33 

U.S.C. 1322) is amended by adding at the end the following: ‘‘(o) MANAGEMENT PRACTICES FOR 

RECREATIONAL VESSELS.— 

‘‘(1) APPLICABILITY.—This subsection applies to any discharge, other than a discharge of sewage, from 

a recreational vessel that is— 

‘‘(A) incidental to the normal operation of the vessel; and 

‘‘(B) exempt from permitting requirements under section 402(r). ‘‘(2) DETERMINATION OF DISCHARGES 

SUBJECT TO MANAGEMENT PRACTICES.— ‘‘(A) DETERMINATION.— ‘‘(i) IN GENERAL.—The Administrator, in 

C-3 
Appendix C – Public Law 110-299 (S. 3298) and Public Law 110-288 (S. 2766) 

consultation with the Secretary of the department in which the Coast Guard is operating, the 

Secretary of Commerce, and interested States, shall determine the discharges incidental to the 

normal operation of a recreational vessel for which it is reasonable and practicable to develop 

management practices to mitigate adverse impacts on the waters of the United States. ‘‘(ii) 

PROMULGATION.—The Administrator shall promulgate the determinations under clause (i) in 

accordance with section 553 of title 5, United States Code. ‘‘(iii) MANAGEMENT PRACTICES.—The 

Administrator shall develop management practices for recreational vessels in any case in which the 

Administrator determines that the use of those practices is reasonable and practicable. ‘‘(B) 

CONSIDERATIONS.—In making a determination under subparagraph (A), the Administrator shall 

consider— ‘‘(i) the nature of the discharge; ‘‘(ii) the environmental effects of the discharge; ‘‘(iii) the 

practicability of using a management practice; ‘‘(iv) the effect that the use of a management practice 

would have on the operation, operational capability, or safety of the vessel; ‘‘(v) applicable Federal 

and State law; ‘‘(vi) applicable international standards; and ‘‘(vii) the economic costs of the use of the 

management practice. ‘‘(C) TIMING.—The Administrator shall— ‘‘(i) make the initial determinations 

under subparagraph (A) not later than 1 year after the date of enactment of this subsection; and ‘‘(ii) 

every 5 years thereafter— ‘‘(I) review the determinations; and ‘‘(II) if necessary, revise the 

determinations based on any new information available to the Administrator. ‘‘(3) PERFORMANCE 

STANDARDS FOR MANAGEMENT PRACTICES.— 

‘‘(A) IN GENERAL.—For each discharge for which a management practice is developed under 

paragraph (2), the Administrator, in consultation with the Secretary of the department in which the 

Coast Guard is operating, the Secretary of Commerce, other interested Federal agencies, and 

interested States, shall promulgate, in accordance with section 553 of title 5, United States Code, 

Federal standards of performance for each management practice required with respect to the 

discharge. 

‘‘(B) CONSIDERATIONS.—In promulgating standards under this paragraph, the Administrator shall 

take into account the considerations described in paragraph (2)(B). 

‘‘(C) CLASSES, TYPES, AND SIZES OF VESSELS.—The standards promulgated under this 

paragraph may— ‘‘(i) distinguish among classes, types, and sizes of vessels; ‘‘(ii) 

distinguish between new and existing vessels; and 

‘‘(iii) provide for a waiver of the applicability of the standards as necessary or appropriate to a 

particular class, type, age, or size of vessel. ‘‘(D) TIMING.—The Administrator shall— 

‘‘(i) promulgate standards of performance for a management practice under subparagraph (A) not 

later than 1 year after the date of a determination under paragraph (2) that the management 

practice is reasonable and practicable; and 

‘‘(ii) every 5 years thereafter— ‘‘(I) review the standards; and ‘‘(II) if necessary, revise the standards, 

in accordance with subparagraph (B) and based on any new information available to the 

Administrator. 

‘‘(4) REGULATIONS FOR THE USE OF MANAGEMENT PRACTICES.— 

‘‘(A) IN GENERAL.—The Secretary of the department in which the Coast Guard is operating shall 

promulgate such regulations governing the design, construction, installation, and use of 

management practices for recreational vessels as are necessary to meet the standards of 

performance promulgated under paragraph (3). 

‘‘(B) REGULATIONS.— 

‘‘(i) IN GENERAL.—The Secretary shall promulgate the regulations under this paragraph as 

soon as practicable after the Administrator promulgates standards with respect to the 

practice under paragraph (3), but not later than 1 year after the date on which the 

Administrator promulgates the standards. 

‘‘(ii) EFFECTIVE DATE.—The regulations promulgated by the Secretary under this paragraph 

shall be effective upon promulgation unless another effective date is specified in the 

regulations. 

‘‘(iii) CONSIDERATION OF TIME.—In determining the effective date of a regulation promulgated 

under this paragraph, the Secretary shall consider the period of time necessary to 

communicate the existence of the regulation to persons affected by the regulation. 

C-4 
Appendix C – Public Law 110-299 (S. 3298) and Public Law 110-288 (S. 2766) 

C-5 

‘‘(5) EFFECT OF OTHER LAWS.—This subsection shall not affect the application of section 311 to 

discharges incidental to the normal operation of a recreational vessel. 

‘‘(6) PROHIBITION RELATING TO RECREATIONAL VESSELS.— After the effective date of the regulations 

promulgated by the Secretary of the department in which the Coast Guard is operating under 

paragraph (4), the owner or operator of a recreational vessel shall neither operate in nor discharge 

any discharge incidental to the normal operation of the vessel into, the waters of the United States 

or the waters of the contiguous zone, if the owner or operator of the vessel is not using any applicable 

management practice meeting standards established under this subsection.’’. 

Speaker of the House of Representatives. 

Vice President of the United States and President of the Senate. 
Appendix D – List of Target Analytes 

Appendix D 

List of Target Analytes 

Analytical 

Class Analyte Name Analytical Method CAS Number 

Pathogens E. Coli by MF EPA 1603 NA 

Pathogens

E. Coli by MPN 

IDEXX Colilert 18 Quanti-Tray or 

Multiple Tube Fermentation NA

Pathogens Enterococci by MF EPA 1600 NA

Pathogens

Enterococci by MPN 

IDEXX Enterolert Quanti-Tray or 

ASTM D6503-99 NA

Pathogens Fecal Coliform by MF MF-SM9222D NA

Pathogens Fecal Coliform by MPN Multiple Tube Fermentation NA

Classicals Biochemical Oxygen Demand (BOD) SM 5210 B 20th NA

Classicals Chemical Oxygen Demand (COD) 

Chemical Oxygen Demand by 

HACH NA

Classicals Conductivity A2510B NA

Classicals Dissolved Organic Carbon (DOC) SM5310 B NA

Classicals Dissolved Oxygen SM 4500-O G NA

Classicals Hexane Extractable Material (HEM) USEPA-1664A NA

Classicals pH SM 4500-H B NA

Classicals Salinity SM 2520 A NA

Classicals Silica Gel Treated HEM (SGT-HEM) USEPA-1664A 68334-30-5 

Classicals Sulfide SM4500S2D 18496-25-8 

Classicals Temperature SM 2550 NA

Classicals Total Organic Carbon (TOC) SM5310 B NA

Classicals Total Residual Chlorine SM 4500-Cl G NA

Classicals Total Suspended Solids (TSS) SM 2540 D 20th NA

Classicals Turbidity EPA 180.1 NA

Metals Aluminum, Dissolved EPA200.7 7429-90-5 

Metals Aluminum, Dissolved EPA200.8 7429-90-5 

Metals Aluminum, Total EPA200.7 7429-90-5 

Metals Aluminum, Total EPA200.8 7429-90-5 

Metals Antimony, Dissolved EPA200.8 7440-36-0 

Metals Antimony, Total EPA200.8 7440-36-0 

Metals Arsenic, Dissolved EPA200.7 7440-38-2 

Metals Arsenic, Dissolved EPA200.8 7440-38-2 

Metals Arsenic, Total EPA200.7 7440-38-2 

Metals Arsenic, Total EPA200.8 7440-38-2 

Metals Barium, Dissolved EPA200.8 7440-39-3 

Metals Barium, Total EPA200.7 7440-39-3 

Metals Barium, Total EPA200.8 7440-39-3 

Metals Beryllium, Dissolved EPA200.8 7440-41-7 

Metals Beryllium, Total EPA200.8 7440-41-7 

Metals Cadmium, Dissolved EPA200.7 7440-43-9 

Metals Cadmium, Dissolved EPA200.8 7440-43-9 

Metals Cadmium, Total EPA200.7 7440-43-9 

Metals Cadmium, Total EPA200.8 7440-43-9 

Metals Calcium, Dissolved EPA200.7 7440-70-2 

Metals Calcium, Total EPA200.7 7440-70-2 

Metals Chromium, Dissolved EPA200.7 7440-47-3 

Metals Chromium, Dissolved EPA200.8 7440-47-3 

Metals Chromium, Total EPA200.7 7440-47-3 

Metals Chromium, Total EPA200.8 7440-47-3 

D-1 
Appendix D – List of Target Analytes 

Analytical 

Class Analyte Name Analytical Method CAS Number 

Metals Cobalt, Dissolved EPA200.8 7440-48-4 

Metals Cobalt, Total EPA200.8 7440-48-4 

Metals Copper, Dissolved EPA200.7 7440-50-8 

Metals Copper, Dissolved EPA200.8 7440-50-8 

Metals Copper, Total EPA200.7 7440-50-8 

Metals Copper, Total EPA200.8 7440-50-8 

Metals Iron, Dissolved EPA200.7 7439-89-6 

Metals Iron, Total EPA200.7 7439-89-6 

Metals Lead, Dissolved EPA200.7 7439-92-1 

Metals Lead, Dissolved EPA200.8 7439-92-1 

Metals Lead, Total EPA200.7 7439-92-1 

Metals Lead, Total EPA200.8 7439-92-1 

Metals Magnesium, Dissolved EPA200.7 7439-95-4 

Metals Magnesium, Total EPA200.7 7439-95-4 

Metals Manganese, Dissolved EPA200.7 7439-96-5 

Metals Manganese, Dissolved EPA200.8 7439-96-5 

Metals Manganese, Total EPA200.7 7439-96-5 

Metals Manganese, Total EPA200.8 7439-96-5 

Metals Nickel, Dissolved EPA200.7 7440-02-0 

Metals Nickel, Dissolved EPA200.8 7440-02-0 

Metals Nickel, Total EPA200.7 7440-02-0 

Metals Nickel, Total EPA200.8 7440-02-0 

Metals Potassium, Dissolved EPA200.7 2023695 

Metals Potassium, Total EPA200.7 2023695 

Metals Selenium, Dissolved EPA200.7 7782-49-2 

Metals Selenium, Dissolved EPA200.8 7782-49-2 

Metals Selenium, Total EPA200.7 7782-49-2 

Metals Selenium, Total EPA200.8 7782-49-2 

Metals Silver, Dissolved EPA200.8 7440-22-4 

Metals Silver, Total EPA200.8 7440-22-4 

Metals Sodium, Dissolved EPA200.7 7440-23-5 

Metals Sodium,Total EPA200.7 7440-23-5 

Metals Thallium, Dissolved EPA200.8 7440-28-0 

Metals Thallium, Total EPA200.8 7440-28-0 

Metals Vanadium, Dissolved EPA200.8 7440-62-2 

Metals Vanadium,Total EPA200.8 7440-62-2 

Metals Zinc, Dissolved EPA200.7 7440-66-6 

Metals Zinc, Dissolved EPA200.8 7440-66-6 

Metals Zinc, Total EPA200.7 7440-66-6 

Metals Zinc, Total EPA200.8 7440-66-6 

Nonylphenols Bisphenol A MS004 NA

Nonylphenols Nonylphenol decaethoxylate (NP10EO) MS006 NA

Nonylphenols Nonylphenol diethoxylate (NP2EO) MS004 NA

Nonylphenols Nonylphenol dodecaethoxylate (NP12EO) MS006 NA

Nonylphenols 

Nonylphenol heptadecaethoxylate 

(NP17EO) MS006 

NA

Nonylphenols Nonylphenol heptaethoxylate (NP7EO) MS006 NA

Nonylphenols Nonylphenol hexadecaethoxylate (NP16EO) MS006 NA

Nonylphenols Nonylphenol hexaethoxylate (NP6EO) MS006 NA

Nonylphenols Nonylphenol monoethoxylate MS004 NA

Nonylphenols Nonylphenol nonaethoxylate (NP9EO) MS006 NA

Nonylphenols Nonylphenol octaethoxylate (NP8EO) MS006 NA

Nonylphenols Nonylphenol octodecaethoxylate (NP18EO) MS006 NA

D-2 
Appendix D – List of Target Analytes 

Analytical 

Class Analyte Name Analytical Method CAS Number 

Nonylphenols Nonylphenol pendecaethoxylate (NP15EO) MS006 NA

Nonylphenols Nonylphenol pentaethoxylate (NP5EO) MS006 NA

Nonylphenols Nonylphenol tetradecaethoxylate (NP14EO) MS006 NA

Nonylphenols Nonylphenol tetraethoxylate (NP4EO) MS006 NA

Nonylphenols Nonylphenol tridecaethoxylate (NP13EO) MS006 NA

Nonylphenols Nonylphenol triethoxylate (NP3EO) MS006 NA

Nonylphenols Nonylphenol undecaethoxylate (NP11EO) MS006 NA

Nonylphenols Octylphenol MS004 NA

Nonylphenols Octylphenol decaethoxylate (OP10EO) MS006 NA

Nonylphenols Octylphenol diethoxylate (OP2EO) MS006 NA

Nonylphenols Octylphenol dodecaethoxylate (OP12EO) MS006 NA

Nonylphenols Octylphenol heptaethoxylate (OP7EO) MS006 NA

Nonylphenols Octylphenol hexaethoxylate (OP6EO) MS006 NA

Nonylphenols Octylphenol nonaethoxylate (OP9EO) MS006 NA

Nonylphenols Octylphenol octaethoxylate (OP8EO) MS006 NA

Nonylphenols Octylphenol pentaethoxylate (OP5EO) MS006 NA

Nonylphenols Octylphenol tetraethoxylate (OP4EO) MS006 NA

Nonylphenols Octylphenol triethoxylate (OP3EO) MS006 NA

Nonylphenols Octylphenol undecaethoxylate (OP11EO) MS006 NA

Nonylphenols Total Nonylphenol Polyethoxylates MS006 NA

Nonylphenols Total Nonylphenols MS004 NA

Nonylphenols Total Octylphenol Polyethoxylates MS006 NA

Nutrients Ammonia As Nitrogen (NH3-N) Ammonia by 4500-NH3 7664-41-7 

Nutrients Nitrate/Nitrite (NO3/NO2-N) EPA353.2 NA 

Nutrients Total Kjeldahl Nitrogen (TKN) EPA351.2 NA 

Nutrients Total Phosphorus Total Phosphorus by 365.4 7723-14-0 

SVOC 1,2-Diethyl-Cyclobutane SVOCs by EPA 625 NA 

SVOC 1,2-Diphenyl hydrazine SVOCs by EPA 625 122-66-7 

SVOC 1,6-dimethylnaphthalene SVOCs by EPA 625 575-43-9 

SVOC 1-methylnaphthalene SVOCs by EPA 625 90-12-0 

SVOC 2,4,5-Trichlorophenol SVOCs by EPA 625 95-95-4 

SVOC 2,4,6-Trichlorophenol SVOCs by EPA 625 88-06-2 

SVOC 2,4-Dichlorophenol SVOCs by EPA 625 120-83-2 

SVOC 2,4-Dimethylphenol SVOCs by EPA 625 105-67-9 

SVOC 2,4-Dinitrophenol SVOCs by EPA 625 51-28-5 

SVOC 2,4-Dinitrotoluene SVOCs by EPA 625 121-14-2 

SVOC 2,6,10,14-Tetramethyl Pentadecane SVOCs by EPA 625 1921-70-6 

SVOC 2,6-Dinitrotoluene SVOCs by EPA 625 606-20-2 

SVOC 2-Butoxy ethanol SVOCs by EPA 625 NA 

SVOC 2-Chloronaphthalene SVOCs by EPA 625 91-58-7 

SVOC 2-Chlorophenol SVOCs by EPA 625 95-57-8 

SVOC 2-Cyclopenten1-one SVOCs by EPA 625 NA 

SVOC 2-Hydroxy-Benzaldehyde SVOCs by EPA 625 90-02-8 

SVOC 2-Mercaptobenzothiazole SVOCs by EPA 625 149-30-4 

SVOC 2-Methylnaphthalene SVOCs by EPA 625 91-57-6 

SVOC 2-Naphthalenecarboxaldehyde SVOCs by EPA 625 NA 

SVOC 2-Nitroaniline SVOCs by EPA 625 88-74-4 

SVOC 2-Nitrophenol SVOCs by EPA 625 88-75-5 

SVOC 3,3'-Dichlorobenzidine SVOCs by EPA 625 91-94-1 

SVOC 3,6-Dimethylundecane SVOCs by EPA 625 NA

SVOC 3-Methyl-2-Heptanone SVOCs by EPA 625 NA

SVOC 3-Methyl-Benzaldehyde SVOCs by EPA 625 620-23-5 

SVOC 3-Methyl-Butanoic Acid SVOCs by EPA 625 NA

D-3 
Appendix D – List of Target Analytes 

Analytical 

Class Analyte Name Analytical Method CAS Number 

SVOC 3-Methylphenol SVOCs by EPA 625 NA

SVOC 3-Nitroaniline SVOCs by EPA 625 99-09-2 

SVOC 3-Phenyl-2-Propenal SVOCs by EPA 625 104-55-2 

SVOC 4,6-Dinitro-2-Methylphenol SVOCs by EPA 625 534-52-1 

SVOC 4-Bromophenyl Phenyl Ether SVOCs by EPA 625 101-55-3 

SVOC 4-Chloro-3-Methylphenol SVOCs by EPA 625 59-50-7 

SVOC 4-Chloroaniline SVOCs by EPA 625 106-47-8 

SVOC 4-Chlorophenyl Phenyl Ether SVOCs by EPA 625 7005-72-3 

SVOC 4-Methyl-Pentanoic Acid SVOCs by EPA 625 NA 

SVOC 4-Nitrobenzenamine SVOCs by EPA 625 100-01-6 

SVOC 4-Nitrophenol SVOCs by EPA 625 100-02-7 

SVOC 5-Butyl-Hexadecane SVOCs by EPA 625 NA 

SVOC Acenaphthene SVOCs by EPA 625 83-32-9 

SVOC Acenaphthylene SVOCs by EPA 625 208-96-8 

SVOC Acetophenone SVOCs by EPA 625 98-86-2 

SVOC Anthracene SVOCs by EPA 625 120-12-7 

SVOC Atrazine SVOCs by EPA 625 1912-24-9 

SVOC Benzeneacetic Acid SVOCs by EPA 625 NA

SVOC Benzenepropanoic Acid SVOCs by EPA 625 NA

SVOC Benzidine SVOCs by EPA 625 92-87-5 

SVOC Benzo(A)Anthracene SVOCs by EPA 625 56-55-3 

SVOC Benzo(A)Pyrene SVOCs by EPA 625 50-32-8 

SVOC Benzo(B)Fluoranthene SVOCs by EPA 625 205-99-2 

SVOC Benzo(G,H,I)Perylene SVOCs by EPA 625 191-24-2 

SVOC Benzo(K)Fluoranthene SVOCs by EPA 625 207-08-9 

SVOC Benzothiazole SVOCs by EPA 625 95-16-9 

SVOC Bicyclo[2.2.1]Heptane,1,7,7-Trimethyl- SVOCs by EPA 625 NA 

SVOC Biphenyla SVOCs by EPA 625 92-52-4 

SVOC Bis (2-Chloroisopropyl)Ether SVOCs by EPA 625 108-60-1 

SVOC Bis(2-Chloroethoxy)Methane SVOCs by EPA 625 111-91-1 

SVOC Bis(2-Chloroethyl)Ether SVOCs by EPA 625 111-44-4 

SVOC Bis(2-Chloroisopropyl) Ether SVOCs by EPA 625 39638-32-9 

SVOC Bis(2-Ethylhexyl) Phthalate SVOCs by EPA 625 117-81-7 

SVOC Butyl Benzyl Phthalate SVOCs by EPA 625 85-68-7 

SVOC Caprolactam SVOCs by EPA 625 105-60-2 

SVOC Carbazole SVOCs by EPA 625 86-74-8 

SVOC Cholesterol SVOCs by EPA 625 NA 

SVOC Chrysene SVOCs by EPA 625 218-01-9 

SVOC Cyclohexadecane SVOCs by EPA 625 NA 

SVOC Dibenz(A,H)Anthracene SVOCs by EPA 625 53-70-3 

SVOC Dibenzofuran SVOCs by EPA 625 132-64-9 

SVOC Diethyl Phthalate SVOCs by EPA 625 84-66-2 

SVOC Dimethyl Phthalate SVOCs by EPA 625 131-11-3 

SVOC Di-N-Butyl Phthalate SVOCs by EPA 625 84-74-2 

SVOC Di-N-Octyl Phthalate SVOCs by EPA 625 117-84-0 

SVOC Dodecane SVOCs by EPA 625 

SVOC Eicosane SVOCs by EPA 625 112-95-8 

SVOC Fluoranthene SVOCs by EPA 625 206-44-0 

SVOC Fluorene SVOCs by EPA 625 86-73-7 

SVOC Heneicosane SVOCs by EPA 625 629-94-7 

SVOC Heptadecane SVOCs by EPA 625 629-78-7 

SVOC Hexachlorobenzene SVOCs by EPA 625 118-74-1 

SVOC Hexachlorobutadienea SVOCs by EPA 625 87-68-3 

D-4 
Appendix D – List of Target Analytes 

Analytical 

Class Analyte Name Analytical Method CAS Number 

SVOC Hexachlorocyclopentadiene SVOCs by EPA 625 77-47-4 

SVOC Hexachloroethane SVOCs by EPA 625 67-72-1 

SVOC Hexadecanoic Acid SVOCs by EPA 625 NA 

SVOC Indeno(1,2,3-Cd)Pyrene SVOCs by EPA 625 193-39-5 

SVOC Indole SVOCs by EPA 625 NA 

SVOC Isophorone SVOCs by EPA 625 78-59-1 

SVOC Isopropylbenzene-4,Methyl-1 SVOCs by EPA 625 99-87-6 

SVOC M-Cresol SVOCs by EPA 625 108-39-4 

SVOC Naphthalene SVOCs by EPA 625 91-20-3 

SVOC N-Hexadecane SVOCs by EPA 625 544-76-3 

SVOC Nitrobenzene SVOCs by EPA 625 98-95-3 

SVOC N-Nitroso Di-N-Propylamine SVOCs by EPA 625 621-64-7 

SVOC N-Nitrosodimethylamine SVOCs by EPA 625 62-75-9 

SVOC N-Nitrosodiphenylamine SVOCs by EPA 625 86-30-6 

SVOC Nonadecane SVOCs by EPA 625 629-92-5 

SVOC Nonanoic Acid SVOCs by EPA 625 NA 

SVOC N-Pentadecanea SVOCs by EPA 625 629-62-9 

SVOC N-Tetradecanea SVOCs by EPA 625 629-59-4 

SVOC O-Cresol SVOCs by EPA 625 95-48-7 

SVOC Octadecane SVOCs by EPA 625 NA 

SVOC P-Cresol SVOCs by EPA 625 106-44-5 

SVOC Pentachlorophenol SVOCs by EPA 625 87-86-5 

SVOC Phenanthrene SVOCs by EPA 625 85-01-8 

SVOC Phenol SVOCs by EPA 625 108-95-2 

SVOC Pyrene SVOCs by EPA 625 129-00-0 

SVOC Triethyl Phosphate SVOCs by EPA 625 NA

VOC (2-Methyl-1-Propenyl)-Benzene VOCs by EPA 624 NA

VOC (E)-2-Butenal VOCs by EPA 624 NA

VOC 1,1,1,2-Tetrachloroethane VOCs by EPA 624 630-20-6 

VOC 1,1,1-Trichloroethane VOCs by EPA 624 71-55-6 

VOC 1,1,2,2-Tetrachloroethane VOCs by EPA 624 79-34-5 

VOC 1,1,2-Trichloroethane VOCs by EPA 624 79-00-5 

VOC 1,1-Dichloroethane VOCs by EPA 624 75-34-3 

VOC 1,1-Dichloroethene VOCs by EPA 624 75-35-4 

VOC 1,1-Dichloropropene VOCs by EPA 624 563-58-6 

VOC 1,2,3,4-Tetrahydro-5-Methylnaphthalene VOCs by EPA 624 2809-64-5 

VOC 1,2,3,4-Tetrahydro-6-Methylnaphthalene VOCs by EPA 624 1680-51-9 

VOC 1,2,3,4-Tetrahydronaphthalene VOCs by EPA 624 119-64-2 

VOC 1,2,3-Trichlorobenzene VOCs by EPA 624 87-61-6 

VOC 1,2,3-Trichloropropane VOCs by EPA 624 96-18-4 

VOC 1,2,4-Trichlorobenzene VOCs by EPA 624 120-82-1 

VOC 1,2,4-Trimethylbenzene VOCs by EPA 624 95-63-6 

VOC 1,2-Dibromo-3-Chloropropane VOCs by EPA 624 96-12-8 

VOC 1,2-Dibromoethane VOCs by EPA 624 106-93-4 

VOC 1,2-Dichlorobenzene VOCs by EPA 624 95-50-1 

VOC 1,2-Dichloroethane VOCs by EPA 624 107-06-2 

VOC 1,2-Dichloropropane VOCs by EPA 624 78-87-5 

VOC 1,3,5-Trimethylbenzene VOCs by EPA 624 108-67-8 

VOC 1,3-Dichlorobenzene VOCs by EPA 624 541-73-1 

VOC 1,3-Dichloropropane VOCs by EPA 624 142-28-9 

VOC 1,3-Methylnaphthalene VOCs by EPA 624 NA 

VOC 1,4-Dichlorobenzene VOCs by EPA 624 106-46-7 

VOC 1,7-Methylnaphthalene VOCs by EPA 624 NA

D-5 
Appendix D – List of Target Analytes 

Analytical 

Class Analyte Name Analytical Method CAS Number 

VOC 1-Ethyl-3-Methyl-Benzene VOCs by EPA 624 NA

VOC 1-Methyl-2-(1-Methylethyl)-Benzene VOCs by EPA 624 NA

VOC 1-Methyl-4-(1-Methylidene)-Cyclohexane VOCs by EPA 624 NA

VOC 1-Methylnaphthaleneb VOCs by EPA 624 90-12-0 

VOC 2- Heptanone VOCs by EPA 624 NA 

VOC 2,2-Dichloropropane VOCs by EPA 624 594-20-7 

VOC 2,3-Dihydro-4-Methyl-1h-Indene VOCs by EPA 624 824-22-6 

VOC 2,6-Dimethylnaphthalene VOCs by EPA 624 581-42-0 

VOC 2-Butanone VOCs by EPA 624 78-93-3 

VOC 2-Butenal VOCs by EPA 624 NA

VOC 2-Ethyl-1,3,5-Trimethyl-Benzene VOCs by EPA 624 NA

VOC 2-Ethyl-1,4-Dimethyl-Benzene VOCs by EPA 624 2039-89-6 

VOC 2-Ethyl-1-Hexanol VOCs by EPA 624 104-76-7 

VOC 2-Hexanone VOCs by EPA 624 591-78-6 

VOC 2-Methylnaphthaleneb VOCs by EPA 624 91-57-6 

VOC 4-Chlorotoluene VOCs by EPA 624 106-43-4 

VOC 4-Isopropyltoluene VOCs by EPA 624 99-87-6 

VOC 4-Methyl-2-Pentanone VOCs by EPA 624 108-10-1 

VOC Acetone VOCs by EPA 624 67-64-1 

VOC Benzaldehyde VOCs by EPA 624 100-52-7 

VOC Benzene VOCs by EPA 624 71-43-2 

VOC Benzocycloheptatriene VOCs by EPA 624 NA 

VOC Benzofuran VOCs by EPA 624 271-89-6 

VOC Biphenyl VOCs by EPA 624 92-52-4 

VOC Bromobenzene VOCs by EPA 624 108-86-1 

VOC Bromochloromethane VOCs by EPA 624 74-97-5 

VOC Bromodichloromethane VOCs by EPA 624 75-27-4 

VOC Bromoform VOCs by EPA 624 75-25-2 

VOC Bromomethane VOCs by EPA 624 74-83-9 

VOC Carbon Disulfide VOCs by EPA 624 75-15-0 

VOC Carbon Tetrachloride VOCs by EPA 624 56-23-5 

VOC Chlorobenzene VOCs by EPA 624 108-90-7 

VOC Chloroethane VOCs by EPA 624 75-00-3 

VOC Chloroform VOCs by EPA 624 67-66-3 

VOC Chloromethane VOCs by EPA 624 74-87-3 

VOC Chlorotoluene VOCs by EPA 624 25168-05-2 

VOC Cis-1,2-Dichloroethene VOCs by EPA 624 156-59-2 

VOC Cis-1,3-Dichloropropene VOCs by EPA 624 10061-01-5 

VOC Cyclohexane VOCs by EPA 624 110-82-7 

VOC Dibromochloromethane VOCs by EPA 624 124-48-1 

VOC Dibromomethane VOCs by EPA 624 74-95-3 

VOC Dichlorodifluoromethane VOCs by EPA 624 75-71-8 

VOC Dimethoxymethane VOCs by EPA 624 NA 

VOC Ethylbenzene VOCs by EPA 624 100-41-4 

VOC Fluorotrimethylsilane VOCs by EPA 624 420-56-4 

VOC Hexachlorobutadiene VOCs by EPA 624 87-68-3 

VOC Isopropylbenzene VOCs by EPA 624 98-82-8 

VOC Limonene VOCs by EPA 624 000138-86-3 

VOC M-,P-Xylene (Sum Of Isomers) VOCs by EPA 624 NA 

VOC Methyl Acetate VOCs by EPA 624 79-20-9 

VOC Methyl Tertiary Butyl Ether (MTBE) VOCs by EPA 624 1634-04-4 

VOC Methylcyclohexane VOCs by EPA 624 108-87-2 

VOC Methylene Chloride VOCs by EPA 624 75-09-2 

D-6 
Appendix D – List of Target Analytes 

D-7 

Analytical 

Class Analyte Name Analytical Method CAS Number 

VOC Naphthaleneb VOCs by EPA 624 91-20-3 

VOC N-Butylbenzene VOCs by EPA 624 104-51-8 

VOC Nonanal VOCs by EPA 624 124-19-6 

VOC N-Pentadecane VOCs by EPA 624 629-62-9 

VOC N-Propylbenzene VOCs by EPA 624 103-65-1 

VOC N-Tetradecane VOCs by EPA 624 629-59-4 

VOC O-Xylene VOCs by EPA 624 95-47-6 

VOC Sec-Butylbenzene VOCs by EPA 624 135-98-8 

VOC Styrene VOCs by EPA 624 100-42-5 

VOC Sulfur Dioxide VOCs by EPA 624 2025884 

VOC Tert-Butylbenzene VOCs by EPA 624 98-06-6 

VOC Tetrachloroethene VOCs by EPA 624 127-18-4 

VOC Tetrahydrofuran VOCs by EPA 624 109-99-9 

VOC Toluene VOCs by EPA 624 108-88-3 

VOC Trans-1,2-Dichloroethene VOCs by EPA 624 156-60-5 

VOC Trans-1,3-Dichloropropene VOCs by EPA 624 10061-02-6 

VOC Trichloroethene VOCs by EPA 624 79-01-6 

VOC Trichlorofluoromethane VOCs by EPA 624 75-69-4 

VOC Trichlorotrifluoroethane VOCs by EPA 624 76-13-1 

VOC Trimethylsilanol VOCs by EPA 624 1066-40-6 

VOC Vinyl Acetate VOCs by EPA 624 108-05-4 

VOC Vinyl Chloride VOCs by EPA 624 75-01-4 a Also measured analytically as a VOC using EPA Method 624. For the purposes of this report, this compound has been classified 

as a VOC to keep with other similar compounds. 

b

 Also measured analytically as a SVOC using EPA Method 625. For the purposes of this report, this compound has been classified 

as an SVOC to keep with other PAHs. 

NA = Not Applicable. 
Appendix E – Analyte Concentrations and Summary Statistics from Ambient Water Samples 

E-1 

Appendix E 

Analyte Concentrations and Summary Statistics from Ambient 

Water Samples 

Analyte - Ambient Waterb,c #Waters Min. Mean Median Max. Screening BM Non Detects Det. Limit(s)

Acetone 10 0.9 2.81 2.25 9.2 n/a 2 5

Aluminum, Dissolved 16 3.1 218.9 38.6 870 n/a 2 6.2

Aluminum, Total 16 29.2 653.9 357.5 3950 87 0

Ammonia As Nitrogen (NH3-N) 15 0.02 0.15 0.066 0.93 1.2 6 0.04, 0.05

Arsenic, Dissolved 17 1 8.09 2 30 36 8 1, 4

Arsenic, Total 17 1 8.19 2.9 28.9 0.018 8 1, 4

Barium, Dissolved 10 14.2 39.04 34.55 65.2 n/a 0

Barium, Total 10 13.3 45.96 33.9 96.3 1000 0

Biochemical Oxygen Demand (BOD) 14 0.479 2.68 1.35 9.3 30 4 1, 4

Calcium, Dissolved 17 23000 104382 72100 310000 n/a 0

Calcium, Total 17 23000 107876 71100 320000 n/a 0

Chemical Oxygen Demand (COD) 15 10 298.3 72 1700 n/a 3 20

Conductivity 15 0.2215 10.49 7.18 38.2 n/a 0

Copper, Dissolved 17 1.5 4.88 2.5 24.2 3.1a 7 5

Copper, Total 17 1.8 5.74 4 23.3 1300 7 5

Dissolved Organic Carbon (DOC) 17 1 4.66 4.4 8.5 n/a 1 3

Dissolved Oxygen 15 1 6.69 6.5 12.33 n/a 0

E. Coli 9 5 3236 130 24196 130 1 10

Enterococci 9 5 1387 333 5099 33 1 10

Fecal Coliform 8 5 6452 220 44000 14 1 10

Iron, Total 10 50 812.2 382 4180 300 2 100

Magnesium, Dissolved 17 6000 304644 172000 1100000 n/a 0

Magnesium, Total 17 6000 306001 168000 1100000 n/a 0

Manganese, Dissolved 17 0.5 11.71 3.7 106 n/a 7 1, 2.5, 6.7, 17 

Manganese, Total 17 1.25 60.54 43 165 100 2 2.5, 13

Nickel, Dissolved 17 2.3 4.60 5 7.2 8.2a 7 10

Nickel, Total 17 2.4 5.81 5 16.7 610 7 10

Nitrate/Nitrite (NO3/NO2-N) 15 0.025 0.36 0.097 1.5 n/a 6 0.05

pH 16 6.90 7.41 7.26 8.18 n/a 0

Potassium, Dissolved 10 3600 72198 60700 175000 n/a 0

Potassium, Total 10 3470 71119 59750 174000 n/a 0

Salinity 14 0.1 6.06 3.85 22.4 n/a 0

Selenium, Dissolved 17 1 22.51 5 100 5

a 7 2, 10

Selenium, Total 17 1 22.71 5 93.9 170 10 2, 10

Sodium, Dissolved 10 17600 1446690 1009500 3630000 n/a 0

Sodium,Total 10 17400 1459630 1160000 3680000 n/a 0

Temperature 16 8.8 20.07 21.575 29.37 n/a 0

Total Kjeldahl Nitrogen (TKN) 15 0.05 1.00 0.587 4.7 n/a 3 0.1

Total Organic Carbon (TOC) 13 2 6.12 5.1 19 n/a 0

Total Phosphorus 15 0.0125 0.20 0.059 2 0.1 6 0.025, 0.05

Total Suspended Solids (TSS) 17 5 22.13 15 98 n/a 1 10

Turbidity 16 0.03 32.01 17.5 186 n/a 0

Vanadium, Dissolved 10 0.5 0.94 0.5 2.3 n/a 6

Vanadium,Total 10 0.5 2.90 1.6 9.3 n/a 5 1, 2.5, 10

Zinc, Dissolved 17 3.4 19.32 11.4 116 81 4 10

Zinc, Total 17 2.9 10.98 10.6 23.9 7400 4 10

 
Appendix E – Analyte Concentrations and Summary Statistics from Ambient Water Samples 

E-2 

Note: 

(a) Screening benchmark (BM) is below detection limit(s)

(b) Analytes not listed in this table were not detected. 

(c) Surrounding Ambient water (also used as service water on select vessels for deck washdown, firemain systems, or other 

services as specified in Chapter 3) was tested for the following classes of pollutants: pathogens, dissolved and total metals, the socalled ‘classical pollutants’, nutrient and nutrient related parameters, VOCs and SVOCs (see Appendix D).
Appendix F – Analyte Concentrations and Summary Statistics from Source Water Samples 

F-1 

Appendix F 

Analyte Concentrations and Summary Statistics from Source Water 

Samples 

Analyte - Source Waterb,c #Waters Min. Mean Median Max. Screening BM Non Detects Det. Limit(s) Alu

minum, Dissolved 11 6.3 64.94 17.1 310 n/a 1 50

Aluminum, Total 11 8.6 64.06 27.5 250 87 1 50

Ammonia As Nitrogen (NH3-N) 10 0.02 0.18 0.041 0.731 1.2 5 0.04,0.05

Barium, Dissolved 7 11.4 29.14 29 58.5 n/a 0

Barium, Total 7 11.9 29.07 30.1 56.9 1000 0

8 2 a Bromodichloromethane 1.25 7.84 5.65 18 0.55 2.5, 5

Calcium, Dissolved 11 1450 28496 29600 88000 n/a 0

Calcium, Total 11 1280 28409 29700 88000 n/a 0

Chemical Oxygen Demand (COD) 11 5 11.55 10 28.6 n/a 6 10, 20

Chloroform 8 0.05 18.56 16 57.2 5.7 0

Conductivity 10 0.159 33.39 0.4075 330.4 n/a 0

Copper, Dissolved 11 2.4 16.11 6.2 65 3.1a 2 5

Copper, Total 11 2.5 20.55 8.7 82 1300 2 5

Dibromochloromethane 8 0.9 3.38 2.45 10 0.4a 3 2.5, 5

Dissolved Oxygen 10 2.07 6.87 6.96 11.72 n/a 0

Magnesium, Dissolved 11 250 6815 7100 19000 n/a 2 500, 1000

Magnesium, Total 11 350 6855 7300 19000 n/a 2 1000

Manganese, Dissolved 11 0.5 6.00 1.25 33 n/a 6 1, 2.5

Manganese, Total 11 1 9.30 5.4 37 100 1 2.5

Nitrate/Nitrite (NO3/NO2-N) 11 0.025 1.26 1.6 2.4 n/a 1 0.05

pH 11 6.61 7.37 7.08 8.45 n/a 0

Potassium, Dissolved 7 1000 3077 3340 5220 n/a 2 2000, 3000

Potassium, Total 7 1000 3003 2840 5270 n/a 1 2000

Sodium, Dissolved 7 16100 56057 24300 140000 n/a 0

Sodium,Total 7 11500 55143 24100 144000 n/a 0

Temperature 10 5.47 20.42 21.16 31.16 n/a 0

Total Kjeldahl Nitrogen (TKN) 10 0.05 0.66 0.401 1.8 n/a 1 0.1

Total Organic Carbon (TOC) 8 1.5 3.21 2.35 10.4 n/a 3 3

Total Phosphorus 10 0.025 0.30 0.363 0.52 0.1 2 0.05

Total Residual Chlorine 10 0.05 0.46 0.415 1.3 0.0075a 3 0.1

Turbidity 11 0.5 5.89 2 19.3 n/a 2 1

Zinc, Dissolved 11 4.1 154.8 25.3 1200 81 0

Zinc, Total 11 4.1 145.3 25.1 1100 7400 0

Note: 

(a) Screening benchmark (BM) is below detection limit(s)

(b) Analytes not listed in this table were not detected. 

(c) Source and service water was tested for the following classes of pollutants: pathogens, dissolved and total metals, the so-called 

‘classical pollutants’, nutrient and nutrient related parameters, VOCs and SVOCs (see Appendix D).
Appendix G – Supporting Information for EPA’s Screenin

Appendix G SUPPORTING INFORMATION FOR EPA’S SCREENING-LEVEL WATER QMODEL 

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Discharge 

Type 

Flow 

Rate 

(m3/day) 

Known Information Assumptions Calcu

Fire Boat Deck Wash 0.01 

1 deck wash per month 50 gallons per wash All deck washes done pier side 

50 gal per month/30 day

Fire Boat Generator Engine 1.82 1 generator Inboard diesel engine 

2 gpm cooling water flow rate 4 hours operation when fire call 1 fire call per day 

2 gal per minute X 240 m

Fire Boat Propulsion Engine 36.34 2 propulsion engines 420 hp inboard engine 20 gpm cooling water flow 4 hours operation when fire call 20 gal per minute X 240 min per day X 2 engines = 9600 gal/day Fishing (Gillnetter) Fish Hold 1.52 1.5 tons of ice per offload 1 offload per day 1.5 tons of ice (or 1524 k

offload/day = 1524 liter

Fishing (Gillnetter) Fish Hold 0.08 

50 lbs (25.2 liters) if ice per offload offloads daily 

75.6 liters/day 

Fishing (Gillnetter) Fish Hold 0.70 

1.75 tons of ice per offload Offload daily 

Ice tank holds 50% fish, 35% ice, 15% air (0.61tons of ice or 691.48 liters of ice) 

691.47 liters/day 

Fishing (Gillnetter) 

Propulsion Engine 14.93 

20 gpm cooling water flow rate 1200 hours per year in operation 

20 gal/min X 60 min/hou= 3945 gal/day 

G-1
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Fishing (Gillnetter) 

Propulsion Engine 14.93 1 Caterpillar 350hp 

20 gpm cooling water flow rate 1200 hours per year in operation 

20 gal/min X 60 min/hou= 3945 gal/day 

Fishing (Gillnetter) 

Propulsion Engine 14.93 

20 gpm cooling water flow rate 1200 hours per year in operation 

20 gal/min X 60 min/hou= 3945 gal/day 

Fishing (Gillnetter) 

Propulsion Engine 14.93 

20 gpm cooling water flow rate 1200 hours per year in operation 

20 gal/min X 60 min/hou= 3945 gal/day 

Fishing (Lobster Boat) Fish Hold 2.83 

Used average of known Longliner fish hold flow rates 

Fishing (Longliner) 

Bilge Water 0.45 1 manual pump 

12v bilge pump at 20 gpm 10 minutes per pump out 2 pump outs per day 

20 gal per min X 10 min gal/day 

Fishing (Longliner) Fish Hold 4.06 8 tons of ice per offload Offload every 2 days Tanks are full at offload 8 tons of ice (or 8128 kg

days = 4064 liters/day 

Fishing (Longliner) Fish Hold 1.59 

Fish hold tank is 8X10X4 ft (9.06 m3) 

Emptied at each offload 

Ice tank holds 50% fish, 35% ice, 15% air (3.17 m3of ice) 

Offloads 1 every 2 days 

9.06 m3 X 35% X 1 offlo

Fishing (Purse Seiner) Fish Hold 31.71 

Fish hold tank is 8X20X20 ft (90.6 m3) 

Emptied at each offload 

ice tank holds 50% fish, 35% ice, 15% air (3.17 m3 of ice) 

offloads daily 

90.6 m3 X 35% = 31.71 m

G-2
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Fishing (Purse Seiner) Fish Hold 15.66 

fish hold tank A is 15X10X6 ft (25.5 m3) 

fish hold tank A is 15X8X6 ft (20.4 m3) 

holds 60,000 lbs of fish (27215 kg) emptied at each offload 

density of fish is 0.9 kg/L offloads daily 

27215 kg / 0.9kg/L = 30

of fish) 45.9 m3 tank - 30.24 m3 

water 15.66 m3 of hold water X 

Fishing (Purse Seiner) Fish Hold 18.36 

 tank holds about 85,000lbs of fish (42,840 liters of fish) 

holding tank is 70% fish, 30% water offloads daily 42,840 liters of fish X 30 

Fishing (Purse Seiner) Fish Hold 10.20 

fish hold tank is 1200 ft3

(33.99 m3) 

emptied at each offload 

holding tank is 70% fish, 30% water offloads daily 33.99 m3 X 30% = 10.2 m

Fishing (Purse Seiner) Fish Hold 5.34 

fish hold tank is 630 ft3

(17.84 m3) 

emptied at each offload 

holding tank is 70% fish, 30% water offloads daily 17.84 m3 X 30% = 5.34 

Fishing (Purse Seiner) 

Fish Hold Clean 1.33 

30 minute wash garden hose flow rate is 11.67 gpm 

11.67 gal per min X 30 mgal/day 

Fishing (Purse Seiner) 

Fish Hold Clean 2.33 

30 minute wash garden hose flow rate is 11.67 gpm 

11.67 gal per min X 30 mgal/day 

Fishing (Purse Seiner) 

Fish Hold Clean 3.33 

30 minute wash garden hose flow rate is 11.67 gpm 

11.67 gal per min X 30 mgal/day 

Fishing (Purse Seiner) 

Fish Hold Clean 0.04 tanks are cleaned 1 per month 30 minute wash garden hose flow rate is 11.67 gpm 11.67 gal per min X 30 m

11.67gal/day 

Fishing (Purse Seiner) 

Fish Hold Clean 3.33 4 month season 

30 minute wash garden hose flow rate is 11.67 gpm 

11.67 gal per min X 30 mgal/day 

Fishing (Purse Seiner) 

Generator Engine 1.41 17,000 hours over 15 years 2 gpm cooling flow 2 gal/min X 60 min/hr X 

days = 372.6 gal/day 

G-3
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Fishing (Purse Seiner) 

Propulsion Engine 16.59 

1 Cummin 350hp inboard diesel engine 4000 hours in 3 years 

20 gpm cooling flow 20 gal/min X 60 min/hr X 

days = 4383.6 gal/day 

Research Propulsion Engine 0.03 

1 200hp gas outboard engine 5 years old 250 hours of use 

1 gpm cooling water flow rate 

1 gal per minute X 250 hengines X 365 days/year 

Research Propulsion Engine 0.15 

2 225 hp gas outboard engine 5 years old 600 hours of use 

1 gpm cooling water flow rate 

1 gal per minute X 600 hengines X 365 days/year 

Fishing (Shrimp Trawler) 

Bilge Water 2.84 

5 min per pump out 1 pump out every day 150 gal/min bilge pump rate 

150gpm, 5 min per pump out, once a day: 750 gal/day 150 gal per min X 5 min 

Fishing (Shrimp Trawler) 

Deck Wash 0.66 

1 deck wash per day 15 minute deck wash with garden hose 

garden hose flow rate is 11.67 gpm 

11.67 gal per min X 15 m175.05 gal/day 

Fishing (Shrimp Trawler) 

Deck Wash 0.76 200 gallons per day 200 gal/ day 

Fishing (Shrimp Trawler) 

Deck Wash 0.15 

1 deck wash per offload 10 minute deck wash with garden hose 

1 offload every 3 days Garden hose flow rate is 11.67 gpm 

11.67 gal per min X 10 m38.9 gal/day 

Fishing (Shrimp Trawler) Fish Hold 0..22 

Holding tank hold 3000lbs of shrimp 

Density of fish is 0.9 kg/literHolding tank is 70%shrimp, 30% water Offloads 1 every 3 days 

1360 kg of fish / 0.9kg/L 1512 X 30%/70% = 648L 648L / 3 days = 216 L/da

Fishing (Shrimp Trawler) Fish Hold 2.12 

Holding tank is 1500 ft3

Generally half full at offload 

Holding tank is 70%shrimp, 30% water Offloads 1 every 3 days 

1500 ft3 X 30% X 1/2 fu

ft3/day 

G-4
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Fishing (Shrimp Trawler) 

Fish Hold Clean 0.13 

15 minute hose down after each offload Offloads 1 every 3 days Garden hose flow rate is 11.67 gpm 

11.67 gal per min X 15 m33.66 gal/day 

Fishing (Shrimp Trawler) 

Fish Hold Clean 0.13 

15 minute hose down after each offload Offloads 1 every 3 days Garden hose flow rate is 11.67 gpm 

11.67 gal per min X 15 m33.66 gal/day 

Fishing (Shrimp Trawler) 

Deck Wash 0.08 1 deck wash per offload 60 gallons per wash 1 offload every 3 days 60 gal every 3 days X ye

Fishing (Shrimp Trawler) 

Deck Wash 0.04 1 deck wash per offload 30 gallons per wash 2 offload every 3 days 30 gal every 3 days X ye

Fishing (Shrimp Trawler) Fish Hold 1.77 Used average of known trawler fish hold flow rates Fishing (Shrimp Trawler) Fish Hold 1.42 5000 gallon tank 75% full at offload Holding tank is 70%shrimp, 30% water Offloads 1 every 3 days 5000 gal X 30% X 3/4 fu

375 gal /day 

Fishing (Shrimp Trawler) 

Fish Hold Clean 0.13 

15 minute hose down after each offload Offloads 1 every 3 days Garden hose flow rate is 11.67 gpm 

11.67 gal per min X 15 m33.66 gal/day 

Supply Boat Deck Wash 0.05 Cleaned with hose 15 minute per deckwash Garden hose flow rate is 11.67 gpm 1 wash every 2 weeks 11.67 gal per min X 15 m

=12.5 gal/day 

G-5
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Fishing (Tender Vessel) Fish Hold 32.82 

3 tanks of 2700 ft3 each 

(229.4 m3 total) 

holds 325,000 lbs of fish (147417 kg of fish) emptied at offload 

density of fish is 0.9 kg/L offloads 1 every 2 days 

147417 kg / 0.9kg/L = 1m3 of fish) 

229.4 m3 tank - 163.8 m3 

water 65.6 m3 of hold water X 

m3/day 

Fishing (Tender Vessel) Fish Hold 18.43 

holds 170,000 lbs of fish (77,110 kg of fish) emptied at offload 

density of fish is 0.9 kg/L holding tank is 70% fish, 30% water offloads 1 every 2 days 

77,110 kg / 0.9kg/L = 85

fish) 86 m3 of fish X 30% / 70

18.43 m3/day 

Fishing (Tender Vessel) Fish Hold 6.81 fish hold tank is 1600 ft3 (45.3 m3) 

holding tank is 70% fish, 30% water offloads 1 every 2 days  (480ft3), 

45.3 m3 X 30% X 1 ever

Fishing (Tender Vessel) 

Fish Hold Clean 0.38 

30 minute wash after each offload 1 offload every 2 days garden hose flow rate is 11.67 gpm after each offload, I offload/2days 

11.67 gal per min X 30 m100.95gal/day 

Fishing (Tender Vessel) 

Fish Hold Clean 0.38 

30 minute wash after each offload 1 offload every 2 days garden hose flow rate is 11.67 gpm after each offload, I offload/2days 

11.67 gal per min X 30 m100.95gal/day 

Tour Boat Bilge Water 0.05 5 min to pump bilge 1 pump per week 12v bilge pump at 20 gpm 20 gal per min X 5 min X 

gal/day 

Tour Boat Bilge Water 0.03 pumped very rarely 

12v bilge pump at 20 gpm rarely defined as 1 pump every 2 weeks 5 min to pump bilge 

20 gal per min X 5 min X gal/day 

G-6
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Tour Boat Deck Wash 0.06 1 deck wash per week 10 minute deck wash with a garden hose garden hose flow rate is 11.67 gpm 11.67 gal per min X 10 m

16.67 gal/day 

Tour Boat Deck Wash 0.22 1 deck wash per day 5 minute deck wash with garden hose garden hose flow rate is 11.67 gpm 11.67 gal per min X 5 m

58.35 gal/day 

Tour Boat Generator Engine 5.40 

2 45kw 76hp inboard diesel engine heat exchange system 6 hours per day of operation 

2 gpm cooling flow 2 gal per minute X 360 m

=1440 gal/day 

Tour Boat Generator Engine 2.20 

2 27kw 46hp inboard diesel engines raw water cooled 4500 hours used in last 5 years 

2 gpm cooling flow 2 gal per minute X 900 h

591.78 gal/day 

Tour Boat Propulsion Engine 27.25 

1 catapillar 86hp diesel inboard engine 20 years old heat exchanger 6 hours per day of operation 

20 gpm cooling flow 20 gal per min X 360 mi

gal/day 

Tour Boat Propulsion Engine 54.51 

2 catapilar 275 diesel inboard engines heat exchange system 6 hours per day of operation 

20 gpm cooling flow 20 gal per min X 360 mi

14400 gal/day 

Tour Boat Propulsion Engine 44.80 

2 catapilar 275 diesel inboard engines raw water cooled 9000 hours operated in last 5 years 

20 gpm cooling flow 20 gal per min X 1800 h

= 11836 gal/day 

Tow/Salvage Bilge Water 0.05 2 min per pump out 1 pump out every 3 days 12v bilge pump at 20 gpm 20 gal per min X 2 min X 

gal/day 

G-7
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Tow/Salvage Bilge Water 2.73 

60 gal per minute flow rate 5 second per pump out 1 pump out every 10 minutes 

60 gal per minute X 12 m

Tow/Salvage Deck Wash 0.03 1 deck wash per week 50 gallons per wash 50 gal per wash/7 days pTow/Salvage Deck Wash 0.03 1 deck wash per week 50 gallons per wash 50 gal per wash/7 days pTow/Salvage Deck Wash 0.01 25 gallons per wash 1 deck wash every 2 weeks 25 gal per wash/14 days Tow/Salvage Deck Wash 0.02 2 deck washes per week 20 gallons per wash 20 gal per wash/3.5 days Tow/Salvage Deck Wash 0.03 1 deck wash per week 50 gallons per wash 50 gal per wash/7 days pTow/Salvage Propulsion Engine 0.15 

1 225 hp evinrude etech outboard 1 year old engine with 243 hours raw water cooled 

1 gpm cooling water flow rate 1 gal per min X 243 hour

Tow/Salvage Propulsion Engine 0.91 1 suzuki 225 hp outboard engine operates 4 hours per day 1 gpm cooling water flow rate 1 gal per min X 4 hours/Tow/Salvage Propulsion Engine 0.56 

2 suzuki 175hp gas outboard engines 1800 hours operated in last 4 years 

1 gpm cooling water flow rate 

1 gal per min X 450 hour147.95 gal/day 

Tow/Salvage Propulsion Engine 2.88 1 cummin inboard 380hp diesel engine 463 hours in last 2 years 20 gpm cooling water flow rate 20 gal per min X 231.5 hTow/Salvage Propulsion Engine 0.26 

2 yamaha 150hp outboard gas engines 420 hours operated in last 2 years 

1 gpm cooling water flow rate 

1 gal per min X 210 hour69.04 gal/day 

G-8
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Fishing (Trawler) 

Bilge Water 2.84 

used average of known shrimp trawler bilge flow rates 

150 gal per min X 5 min 

Fishing (Trawler) 

Deck Wash 0.34 

used average of known shrimp trawler deck wash flow rates 

Fishing (Trawler) Fish Hold 1.77 

used average of known shrimp trawler fish hold flow rates 

Fishing (Trawler) 

Fish Hold Clean 0.13 

15 minute hose down after each offload offloads 1 every 3 days garden hose flow rate is 11.67 gpm 

11.67 gal per min X 15 m33.66 gal/day 

Fishing (Troller) 

Deck Wash 0.47 125 gal per power wash 1 wash per day 125 gal/day 

Fishing (Troller) Fish Hold 4.16 

fish hold tank is 12x10x7 ft3 (23.8 m3) 

emptied at each offload tank is offloaded at half full 

ice tank holds 50% fish, 35% ice, 15% air offloads daily 

23.8m3 X 35% X 50% = 

Fishing (Troller) Fish Hold 0.79 600 gallon ice box emptied at each offload ice tank holds 50% fish, 35% ice, 15% air offloads daily 600 gal X 35% = 210 gaFishing (Troller) Fish Hold 1.58 160 ft3 tank (4.53 m3 tank) 

ice tank holds 50% fish, 35% ice, 15% air offloads daily 

4.53 m3 X 35% = 1.58 m

Fishing (Troller) Fish Hold 5.59 

5.5 tons of ice per offload 1 offload per day 

tank holds 5.5 tons of ice (5588.3kg of ice or 6141 liters of ice) and 11,000 of fish, discharged at each offload, offloads daily, 

5.5 tons of ice (5588.3 kgL/day 

G-9
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Fishing (Troller) 

Fish Hold Clean 0.38 

1 deck wash per offload 15 minute deck wash with garden hose 1 offload daily garden hose flow rate is 11.67 gpm 

11.67 gal per min X 15 m

Fishing (Troller) 

Fish Hold Clean 1.38 

2 deck wash per offload 15 minute deck wash with garden hose 1 offload daily garden hose flow rate is 11.67 gpm 

11.67 gal per min X 15 m

Tugboat Deck Wash 0..38 1 deck wash per 2 weeks with garden hose 2 hours per deck wash garden hose flow rate is 11.67 gpm 11.67 gal per min X 120 

100 gal/day 

Tugboat Deck Wash 0.14 1.5 deck washes per week 15 minutes per deck wash garden hose flow rate is 11.67 gpm 11.67 gal per min X 22.5 

37.8 gal/day 

Tugboat Deck Wash 0.17 

1.5 deck washes per week with garden hose 15-20 minutes per deck wash 

garden hose flow rate is 11.67 gpm 11.67 gal per min X 17.5 

43.76 gal/day 

Tugboat Deck Wash 0.14 1 deck wash per 2 week with garden hose 45 minutes per deck wash garden hose flow rate is 11.67 gpm 11.67 gal per min X 45 m

37.51 gal/day 

Tugboat Deck Wash 0.14 

1 deck wash per week with garden hose 15-30 minutes per deck wash 

garden hose flow rate is 11.67 gpm 11.67 gal per min X 22.5 

37.51 gal/day 

Tugboat Deck Wash 0.19 2 deck washes per week with garden hose 15 minutes per deck wash garden hose flow rate is 11.67 gpm 11.67 gal per min X 15 m

50.01 gal/day 

G-10
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Tugboat Deck Wash 0.00 Uses pressure washer at 2 gallons per wash 1 wash every month 2 gal per wash X 1 wash 

gal/day 

Tugboat Deck Wash 0.05 

garden hose flow rate is 11.67 gpm 1 deck washes per 2 weeks with garden hose 15 minutes per deck wash (use data of sister vessel) 

11.67 gal per min X 15 m=12.5 gal/day 

Tugboat Deck Wash 0.05 1 deck washes per 2 weeks with garden hose 15 minutes per deck wash garden hose flow rate is 11.67 gpm 11.67 gal per min X 15 m

=12.5 gal/day 

Tugboat Graywater - Laundry 0.22 front load washer 16 loads per week front load washer uses 25 gal/load 25 gal/load X 16 loads/wTugboat Graywater - Laundry 0.22 front load washer 16 loads per week front load washer uses 25 gal/load 25 gal/load X 16 loads/wTugboat Graywater - Laundry 0.11 standard washer 5 loads per week standard washer uses 40 gal/load 40 gal/load X 5 loads/weTugboat Graywater - Laundry 0.22 front load washer 4 crew 

front load washer uses 25 gal/load 4 loads of laundry per crew per week 

25 gal/load X 16 loads/w

Tugboat Graywater - Laundry 0.13 standard washer 6 loads per week standard washer uses 40 gal/load 40 gal/load X 5 loads/weTugboat Graywater - Laundry 0.02 1 load per week has standard washer standard washer uses 40 gal/load 40 gal/load X 1 loads/weTugboat Graywater - Shower 0.16 3 crew 17.2 gal per shower 0.8 showers per person per day 3 crew X 17.2 gal per sh

person per day = 41.28 g

Tugboat Graywater - Shower 0.16 3 crew 17.2 gal per shower 0.8 showers per person per day 3 crew X 17.2 gal per sh

person per day = 41.28 g

G-11
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Tugboat Graywater - Shower 0.26 5 crew 17.2 gal per shower 0.8 showers per person per day 5 crew X 17.2 gal per sh

person per day = 68.8 ga

Tugboat Graywater - Shower 0.21 4 crew 17.2 gal per shower 0.8 showers per person per day 4 crew X 17.2 gal per sh

person per day = 55.04 g

Tugboat Graywater - Shower 0.21 4 crew 17.2 gal per shower 0.8 showers per person per day 4 crew X 17.2 gal per sh

person per day = 55.04 g

Tugboat Graywater - Shower 0.16 3 crew 17.2 gal per shower 0.8 showers per person per day 3 crew X 17.2 gal per sh

person per day = 41.28 g

Tugboat Graywater - Sink 0.11 3 crew 

30 min of sink use per crew per week 2.2 gal per min in standard sink 

2.2 gal per min X 3 crew gal/day 

Tugboat Graywater - Sink 0.11 3 crew 

30 min of sink use per crew per week 2.2 gal per min in standard sink 

2.2 gal per min X 3 crew gal/day 

Tugboat Graywater - Sink 0.18 5 crew 

30 min of sink use per crew per week 2.2 gal per min in standard sink 

2.2 gal per min X 5 crew gal/day 

Tugboat Graywater - Sink 0.14 4 crew 

30 min of sink use per crew per week 2.2 gal per min in standard sink 

2.2 gal per min X 4 crew gal/day 

Tugboat Graywater - Sink 0.14 4 crew 

30 min of sink use per crew per week 2.2 gal per min in standard sink 

2.2 gal per min X 4 crew gal/day 

G-12
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Tugboat Graywater - Sink 0.11 3 crew 

30 min of sink use per crew per week 2.2 gal per min in standard sink 

2.2 gal per min X 3 crew gal/day 

Tugboat Shaft Water 0.01 operates 5 days/week 10 mL/min constant drip (3.8 gal/day drip) 3.8 gal per day X 5 days/Tugboat Shaft Water 0.01 operates 5 days/week 10 mL/min constant drip (3.8 gal/day drip) 3.8 gal per day X 5 days/Tugboat Shaft Water 0.01 operates 5 days/week 10 mL/min constant drip (3.8 gal/day drip) 3.8 gal per day X 5 days/Tugboat Shaft Water 0.01 operates 5 days/week 10 mL/min constant drip (3.8 gal/day drip) 3.8 gal per day X 5 days/Tugboat Shaft Water 0.01 operates 5 days/week 10 mL/min constant drip (3.8 gal/day drip) 3.8 gal per day X 5 days/Tugboat Shaft Water 0.01 operates 5 days/week 10 mL/min constant drip (3.8 gal/day drip) 3.8 gal per day X 5 days/Tugboat Shaft Water 0.01 operates 5 days/week 10 mL/min constant drip (3.8 gal/day drip) 3.8 gal per day X 5 days/Tugboat Shaft Water 0.01 operates 5 days/week 10 mL/min constant drip (3.8 gal/day drip) 3.8 gal per day X 5 days/Water Taxi Bilge Water 0.13 

2000 gal per hour pump 1 minute per pump out bilge pump operates when engine is turned on 

33.33 gal per min X 1 mout/day =33.2 gal/day 

G-13
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Water Taxi Bilge Water 0.13 

2000 gal per hour pump 1 minute per pump out bilge pump operates when engine is turned on 

33.33 gal per min X 1 mout/day =33.2 gal/day 

Water Taxi Bilge Water 0.13 

2000 gal per hour pump 1 minute per pump out bilge pump operates when engine is turned on 

33.33 gal per min X 1 mout/day =33.2 gal/day 

Water Taxi Deck Wash 0.01 1 deck washes per month with garden hose 10 minutes per deck wash garden hose flow rate is 11.67 gpm 11.67 gal per min X 10 m

3.89 gal/day 

Water Taxi Deck Wash 0.01 1 deck washes per month with garden hose 10 minutes per deck wash garden hose flow rate is 11.67 gpm 11.67 gal per min X 10 m

3.89 gal/day 

Water Taxi Deck Wash 0.09 1 deck washes every week with garden hose 15 minutes per deck wash garden hose flow rate is 11.67 gpm 11.67 gal per min X 15 m

gal/day 

Water Taxi Deck Wash 0.02 

1 deck washes per month with garden hose 12.5 minutes per deck wash 

garden hose flow rate is 11.67 gpm 

11.67 gal per min X 12.5 4.86 gal/day 

Water Taxi Generator Engine 9.08 2 21.5kw diesel generators heat exchange system operates 10 hours/day 2 gal per min cooling flow 2 gal per minute X 600 m

2400 gal/day 

Water Taxi Graywater - Sink 0.28 

100 passengers wash their hands/day faucet flow rate is 2.2 gal/min 20 seconds per wash 

100 passengers/day X 20 gal/min = 73.34 gal/day 

G-14
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.1: Vessel-Specific Flow Calculations by Discharge Type

Vessel Class 

(Vessel Subclass) 

Flow Discharge Rate Known Information Assumptions Calcu

Type (m3/day) 

Water Taxi Propulsion Engine 33.18 

2 95hp diesel inboard engines 20,000 hours of operation in 15 years 

20 gal per min cooling flow 1200 gal per hour X 2 en

= 8765 gal/day 

Water Taxi Propulsion Engine 18.57 

1 caterpillar 220hp diesel inboard 4475 hours of operation in 3 years 

20 gal per min cooling flow 1200 gal per hour X 1,49

gal/day 

Water Taxi Propulsion Engine 90.85 2 John Deer 25hp inboard diesel engines operates 10 hours/day 20 gal per min cooling flow 1200 gal per hour X 2 en

24,000 gal/day 

Water Taxi Propulsion Engine 16.59 

1 90hp diesel inboard engine 20,000 hours of operation in 15 years 

20 gal per min cooling flow 1200 gal per hour X 1,33

gal/day 

G-15
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.2: Percent of Vessels by Vessel Class and Discharge Type Discharging in the Harbor 

Vessel Class Vessel Subclass Discharge 

Number of 

Sampled 

Vessels 

without 

Discharge 

System or 

Process 

(A) 

Number of 

Sampled 

Vessels with 

a No 

Discharge 

System 

(B) 

Number of 

Sampled Vessels 

that 

DischargedOutside 

U.S. Waters 

(C) 

Number of 

Sampled 

Vessels that 

Discharge 

in the 

Harbor 1

(D) 

Tot

of 

(E=

Fire Boat NA Deck Wash 0 0 0 1 Fire Boat NA Engine Effluent 0 0 0 1 Fire Boat NA Fire Main 0 0 0 1 Fire Boat NA Generator Effluent 0 0 0 1 Fishing Gillnetter Deck Wash 0 0 5 0 Fishing Gillnetter Engine Effluent 0 1 0 4 Fishing Gillnetter Fish Hold 0 0 1 4 Fishing Lobster Boat Fish Hold 0 0 0 1 Fishing Longliner Bilge 0 1 1 1 Fishing Longliner Fish Hold 0 0 0 3 Fishing Longliner Fish Hold Clean 0 0 0 3 Fishing Purse Seiner Engine Effluent 0 3 0 2 Fishing Purse Seiner Fish Hold 0 0 0 5 Fishing Purse Seiner Fish Hold Clean 0 0 0 5 Fishing Purse Seiner Generator Effluent 1 2 0 2 Fishing Shrimping Bilge 0 0 5 5 Fishing Shrimping Deck Wash 0 0 2 8 Fishing Shrimping Fish Hold 0 2 0 8 Fishing Shrimping Graywater 0 0 0 10 Fishing Tender Vessel Fish Hold 0 0 0 3 Fishing Tender Vessel Fish Hold Clean 0 0 1 2 Fishing Trawler Deck Wash 0 0 2 8 Fishing Trawler Fish Hold 0 2 0 8 Fishing Trawler Fish Hold Clean 0 3 2 4 Fishing Troller Deck Wash 2 0 3 1 

G-16
Appendix G – Supporting Information for EPA’s Screenin

G-17

Appendix G.2: Percent of Vessels by Vessel Class and Discharge Type Discharging in the Harbor 

Vessel Class Vessel Subclass Discharge 

Number of 

Sampled 

Vessels 

without 

Discharge 

System or 

Process 

(A) 

Number of 

Sampled 

Vessels with 

a No 

Discharge 

System 

(B) 

Number of 

Sampled Vessels 

that 

DischargedOutside 

U.S. Waters 

(C) 

Number of 

Sampled 

Vessels that 

Discharge 

in the 

Harbor 1

(D) 

Tot

of 

(E=

Fishing Troller Fish Hold 0 0 0 6 Fishing Troller Fish Hold Clean 4 0 0 2 Research NA Engine Effluent 0 0 0 2 Supply Boat NA Deck Wash 0 0 0 1 Tour Boat NA Bilge 1 0 0 2 Tour Boat NA Deck Wash 1 0 0 2 Tour Boat NA Engine Effluent 0 0 0 3 Tour Boat NA Fire Main 0 0 0 3 Tour Boat NA Generator Effluent 1 0 0 2 Tow/Salvage NA Bilge 1 3 0 2 Tow/Salvage NA Deck Wash 0 0 0 6 Tow/Salvage NA Engine Effluent 0 1 0 5 Tugboat NA Deck Wash 0 0 0 9 Tugboat NA Fire Main 0 0 0 9 Tugboat NA Graywater 0 3 0 6 Tugboat NA Shaft Water 0 1 0 8 Water Taxi NA Bilge 0 1 0 3 Water Taxi NA Deck Wash 0 0 0 4 Water Taxi NA Engine Effluent 0 0 0 4 Water Taxi NA Generator Effluent 3 0 0 1 Water Taxi NA Graywater 3 0 0 1 (1) - The percentage of vessels discharging to the harbor were determined based on field observations of sampled vessels. As a conservvessel classes with no information available were assumed to discharge in the harbor. 
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

Vessel Scenario 2 

Total Loading 

Rate Large 

Metropolitan 

Harbor 

Vessel 

Scenario 3 

Total Loading 

Rate 

Recreational 

Harbor 

Units 

Bacteria E. Coli by MF 8,860,000,000 44,300,000,000 7,380,000,000 CFU/day 

Bacteria E. Coli by MPN 3,570,000,000 16,000,000,000 2,880,000,000 MPN/day

Bacteria Enterococci by MF 5,000,000,000 25,000,000,000 4,170,000,000 CFU/day 

Bacteria Enterococci by MPN 1,010,000,000 891,000,000 547,000,000 MPN/day

Bacteria Fecal Coliform by MF 27,500,000,000 81,500,000,000 20,300,000,000 CFU/day 

Bacteria Fecal Coliform by MPN 10,000,000,000 50,000,000,000 8,330,000,000 MPN/day

Bacteria Total Coliforms by MPN 42,900,000,000 214,000,000,000 35,800,000,000 MPN/day

Classicals 

Biochemical Oxygen 

Demand (BOD) 635 481 392 lb/day 

Classicals 

Chemical Oxygen Demand 

(COD) 1,840 1,310 1,100 lb/day 

Classicals Dissolved Oxygen 25.6 37.4 41.3 lb/day 

Classicals 

Hexane Extractable Material 

(HEM) 11.4 19.1 17.5 lb/day 

Classicals 

Silica Gel Treated HEM 

(SGT-HEM) 13.2 20.7 20.8 lb/day 

Classicals Sulfide 0.0152 0.0285 0.0203 lb/day 

Classicals 

Total Organic Carbon 

(TOC) 239 185 147 lb/day 

Classicals Total Residual Chlorine 0.403 0.730 0.565 lb/day 

Classicals 

Total Suspended Solids 

(TSS) 231 207 186 lb/day 

Nutrients 

Ammonia As Nitrogen 

(NH3-N) 8.52 6.07 5.07 lb/day 

Nutrients 

Nitrate/Nitrite (NO3/NO2-

N) 0.127 0.203 0.102 lb/day 

Nutrients 

Total Kjeldahl Nitrogen 

(TKN) 97.8 68.5 59.0 lb/day 

Nutrients Total Phosphorus 13.8 8.91 7.74 lb/day 

Metals Aluminum, Dissolved 2.01 1.70 1.64 lb/day 

Metals Aluminum, Total 2.55 2.70 2.60 lb/day 

Metals Antimony, Dissolved 0.0000217 0.000111 0.0000470 lb/day 

Metals Antimony, Total 0.0000711 0.000348 0.000137 lb/day 

Metals Arsenic, Dissolved 1 0.0190 0.0285 0.0256 lb/day 

Metals Arsenic, Total 1 0.0279 0.0359 0.0315 lb/day 

Metals Barium, Dissolved 0.0326 0.0747 0.0666 lb/day 

Metals Barium, Total 0.0368 0.0895 0.0709 lb/day 

Metals Cadmium, Dissolved 0.0000294 0.0000433 0.0000306 lb/day 

Metals Cadmium, Total 0.000749 0.000657 0.000551 lb/day 

Metals Calcium, Dissolved 653 561 528 lb/day 

Metals Calcium, Total 647 566 534 lb/day 

Metals Chromium, Dissolved 0.00195 0.00447 0.00424 lb/day 

Metals Chromium, Total 0.00514 0.00890 0.00713 lb/day 

G-18
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

Vessel Vessel Scenario 2 Scenario 3 Total Loading Total Loading Rate Large Units Rate Metropolitan Recreational Harbor Harbor 

Metals Cobalt, Dissolved 0.0000745 0.000184 0.0000776 lb/day 

Metals Cobalt, Total 0.000148 0.000262 0.000108 lb/day 

Metals Copper, Dissolved 2.88 4.97 2.75 lb/day 

Metals Copper, Total 0.158 0.179 0.165 lb/day 

Metals Iron, Dissolved 0.0161 0.0465 0.0145 lb/day 

Metals Iron, Total 0.376 0.819 0.600 lb/day 

Metals Lead, Dissolved 0.00176 0.00338 0.00340 lb/day 

Metals Lead, Total 0.0108 0.0154 0.0142 lb/day 

Metals Magnesium, Dissolved 1,980 1,500 1,390 lb/day 

Metals Magnesium, Total 1,910 1,470 1,360 lb/day 

Metals Manganese, Dissolved 0.120 0.230 0.255 lb/day 

Metals Manganese, Total 0.148 0.296 0.321 lb/day 

Metals Nickel, Dissolved 0.00854 0.0140 0.0133 lb/day 

Metals Nickel, Total 0.00987 0.0165 0.0145 lb/day 

Metals Potassium, Dissolved 56.0 105 113 lb/day 

Metals Potassium, Total 56.1 105 112 lb/day 

Metals Selenium, Dissolved 1 0.0215 0.0412 0.0443 lb/day 

Metals Selenium, Total 1 0.0244 0.0440 0.0471 lb/day 

Metals Silver, Dissolved 0.0000276 0.0000221 0.0000138 lb/day 

Metals Silver, Total 0.0000519 0.0000415 0.0000259 lb/day 

Metals Sodium, Dissolved 1,240 2,460 2,750 lb/day 

Metals Sodium,Total 1,440 2,880 3,260 lb/day 

Metals Thallium, Dissolved 0.0000144 0.0000710 0.0000120 lb/day 

Metals Thallium,Total 0.000000157 0.000000785 0.000000131 lb/day 

Metals Vanadium, Dissolved 0.00101 0.00201 0.00227 lb/day 

Metals Vanadium,Total 0.00130 0.00269 0.00254 lb/day 

Metals Zinc, Dissolved 0.310 0.295 0.259 lb/day 

Metals Zinc, Total 0.758 0.613 0.516 lb/day 

Nonylphenols Bisphenol A 0.00000886 0.0000177 0.0000213 lb/day 

Nonylphenols 

Nonylphenol decaethoxylate 

(NP10EO) 0.00191 0.00338 0.00314 lb/day 

Nonylphenols 

Nonylphenol 

dodecaethoxylate (NP12EO) 0.00152 0.00270 0.00255 lb/day 

Nonylphenols 

Nonylphenol 

heptadecaethoxylate 

(NP17EO) 0.0000955 0.000170 0.000167 lb/day 

Nonylphenols 

Nonylphenol 

heptaethoxylate (NP7EO) 0.00122 0.00210 0.00177 lb/day 

Nonylphenols 

Nonylphenol 

hexadecaethoxylate 

(NP16EO) 0.000209 0.000362 0.000357 lb/day 

Nonylphenols 

Nonylphenol hexaethoxylate 

(NP6EO) 0.000866 0.00147 0.00117 lb/day 

G-19
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

Vessel Vessel Scenario 2 Scenario 3 Total Loading Total Loading Rate Large Units Rate Metropolitan Recreational Harbor Harbor 

Nonylphenols 

Nonylphenol nonaethoxylate 

(NP9EO) 0.00173 0.00300 0.00276 lb/day 

Nonylphenols 

Nonylphenol octaethoxylate 

(NP8EO) 0.00159 0.00269 0.00239 lb/day 

Nonylphenols 

Nonylphenol 

octodecaethoxylate 

(NP18EO) 0.0000505 0.0000818 0.0000832 lb/day 

Nonylphenols 

Nonylphenol 

pendecaethoxylate 

(NP15EO) 0.000398 0.000684 0.000675 lb/day 

Nonylphenols 

Nonylphenol 

pentaethoxylate (NP5EO) 0.000525 0.000860 0.000596 lb/day 

Nonylphenols 

Nonylphenol 

tetradecaethoxylate 

(NP14EO) 0.000708 0.00124 0.00121 lb/day 

Nonylphenols 

Nonylphenol tetraethoxylate 

(NP4EO) 0.000233 0.000390 0.000173 lb/day 

Nonylphenols 

Nonylphenol 

tridecaethoxylate (NP13EO) 0.00109 0.00191 0.00184 lb/day 

Nonylphenols 

Nonylphenol triethoxylate 

(NP3EO) 0.000131 0.000226 0.0000944 lb/day 

Nonylphenols 

Nonylphenol 

undecaethoxylate (NP11EO) 0.00194 0.00343 0.00321 lb/day 

Nonylphenols 

Octylphenol decaethoxylate 

(OP10EO) 0.0000690 0.000254 0.0000836 lb/day 

Nonylphenols 

Octylphenol 

dodecaethoxylate (OP12EO) 0.0000413 0.000122 0.0000383 lb/day 

Nonylphenols 

Octylphenol heptaethoxylate 

(OP7EO) 0.00000302 0.0000151 0.00000251 lb/day 

Nonylphenols 

Octylphenol nonaethoxylate 

(OP9EO) 0.0000418 0.0000808 0.0000311 lb/day 

Nonylphenols 

Octylphenol octaethoxylate 

(OP8EO) 0.0000257 0.000129 0.0000214 lb/day 

Nonylphenols 

Octylphenol 

undecaethoxylate (OP11EO) 0.0000445 0.000151 0.0000503 lb/day 

Nonylphenols 

Total Nonylphenol 

Polyethoxylates 0.0136 0.0232 0.0215 lb/day 

Nonylphenols Total Nonylphenols 0.000153 0.000122 0.0000763 lb/day 

VOC 

(2-Methyl-1-Propenyl)-

Benzene 0.00298 0.00595 0.00714 lb/day 

VOC (E)-1-Propenyl-Benzene 0.00000135 0.00000675 0.00000540 lb/day 

VOC (E)-2-Butenal 0.00544 0.0109 0.0131 lb/day 

VOC 

1,2,3,4-Tetrahydro-1-

Methylnaphthalene 0.00342 0.00684 0.00821 lb/day 

VOC 

1,2,3,4-Tetrahydro-2-

Methylnaphthalene 0.00316 0.00632 0.00758 lb/day 

G-20
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

Vessel Vessel Scenario 2 Scenario 3 Total Loading Total Loading Rate Large Units Rate Metropolitan Recreational Harbor Harbor 

VOC 

1,2,3,4-Tetrahydro-5-

Methylnaphthalene 0.0277 0.0556 0.0664 lb/day 

VOC 

1,2,3,4-Tetrahydro-6-

Ethylnaphthalene, 0.00298 0.00597 0.00716 lb/day 

VOC 

1,2,3,4-Tetrahydro-6-

Methylnaphthalene 0.0253 0.0512 0.0603 lb/day 

VOC 

1,2,3,4-Tetrahydro-6-

Methylnaphthalene (01) 0.00633 0.0127 0.0152 lb/day 

VOC 

1,2,3,4-Tetrahydro-6-

Methylnaphthalene (02) 0.00530 0.0106 0.0127 lb/day 

VOC 

1,2,3,4-

Tetrahydronaphthalene 0.0190 0.0382 0.0456 lb/day 

VOC 

1,2,3,4-TetramethylBenzene 0.000643 0.00429 0.00214 lb/day 

VOC 

1,2,3,5-TetramethylBenzene 0.000947 0.00631 0.00316 lb/day 

VOC 1,2,3-Trimethylbenzene 0.00309 0.0206 0.0103 lb/day 

VOC 1,2,4,5-Tetramethylbenzene 0.00144 0.00963 0.00481 lb/day 

VOC 1,2,4-Trimethylbenzene 0.00616 0.0281 0.0176 lb/day 

VOC 1,3,5-Trimethylbenzene 0.00166 0.00819 0.00474 lb/day 

VOC 1,3-Methylnaphthalene 0.00391 0.00781 0.00938 lb/day 

VOC 1,7-Methylnaphthalene 0.0177 0.0353 0.0424 lb/day 

VOC 

1-Ethyl-2,3-DimethylBenzene (01) 0.00272 0.00955 0.00735 lb/day 

VOC 

1-Ethyl-2,3-DimethylBenzene (02) 0.000393 0.00262 0.00131 lb/day 

VOC 

1-Ethyl-2,4-DimethylBenzene 0.00153 0.0102 0.00510 lb/day 

VOC 1-Ethyl-2-Methyl-Benzene 0.00000417 0.0000208 0.0000167 lb/day 

VOC 1-Ethyl-3-Methyl-Benzene 0.00327 0.00663 0.00790 lb/day 

VOC 1-Ethyl-4-Methyl-Benzene 0.00644 0.0429 0.0215 lb/day 

VOC 

1-Methyl-2-(1-Methylethyl)-

Benzene 0.00 0.00 0.00 lb/day 

VOC 

1-Methyl-2-(1-Methylethyl)-

Benzene (01) 0.00000337 0.0000169 0.0000135 lb/day 

VOC 

1-Methyl-2-(1-Methylethyl)-

Benzene (02) 0.0000118 0.0000589 0.0000471 lb/day 

VOC 1-Methyl-3-Propyl-Benzene 0.00126 0.00836 0.00419 lb/day 

VOC 

1-Methyl-4-(1-

Methylidene)-Cyclohexane 0.00 0.00 0.00 lb/day 

VOC 1-methyl-Indan 0.00792 0.0201 0.0199 lb/day 

VOC 1-Propenyl-Benzene 0.00000155 0.00000774 0.00000619 lb/day 

VOC 2- Heptanone 0.0000601 0.000400 0.000200 lb/day 

VOC 

2,3-Dihydro-1,2-Dimethyl1H-Indene 0.000323 0.00216 0.00108 lb/day 

G-21
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

Vessel Scenario 2 

Total Loading 

Rate Large 

Metropolitan 

Harbor 

Vessel 

Scenario 3 

Total Loading 

Rate 

Recreational 

Harbor 

Units 

VOC 

2,3-Dihydro-1,6-Dimethyl1H-Indene 0.00356 0.0103 0.00906 lb/day 

VOC 

2,3-Dihydro-1-

Methylindene 0.00518 0.0104 0.0124 lb/day 

VOC 

2,3-Dihydro-1-methylindene 

(01) 0.00290 0.00579 0.00695 lb/day 

VOC 

2,3-Dihydro-1-methylindene 

(02) 0.00614 0.0123 0.0147 lb/day 

VOC 

2,3-Dihydro-4,7-Dimethyl1H-Indene 0.0000409 0.000204 0.0000409 lb/day 

VOC 

2,3-Dihydro-4-Methyl-1HIndene 0.0546 0.119 0.133 lb/day 

VOC 

2,3-Dihydro-4-Methyl-1HIndene (01) 0.00000480 0.0000240 0.0000192 lb/day 

VOC 

2,3-Dihydro-4-Methyl-1HIndene (02) 0.00000810 0.0000405 0.0000324 lb/day 

VOC 

2,3-Dihydro-5,6-dimethyl1H-Indene 0.00281 0.00562 0.00674 lb/day 

VOC 

2,3-Dihydro-5-methyl-1HIndene 0.00159 0.0106 0.00530 lb/day 

VOC 2,6-Dimethylnaphthalene 0.0384 0.0769 0.0923 lb/day 

VOC 2-Butanone 0.0297 0.0613 0.0706 lb/day 

VOC 2-Butenal 0.00340 0.00679 0.00815 lb/day 

VOC 

2-Ethyl-1,3,5-TrimethylBenzene 0.00409 0.00819 0.00982 lb/day 

VOC 

2-Ethyl-1,4-DimethylBenzene 0.0189 0.0378 0.0454 lb/day 

VOC 2-Ethyl-1-Hexanol 0.00000111 0.00000741 0.00000370 lb/day 

VOC 2-Ethyltoluene 0.00541 0.0209 0.0150 lb/day 

VOC 2-Hexanone 0.00262 0.00562 0.00618 lb/day 

VOC 2-Methyl-2-Propenal 0.00632 0.0130 0.0150 lb/day 

VOC 2-Propenyl-Benzene 0.00471 0.0314 0.0157 lb/day 

VOC 3-Buten-2-one 0.00578 0.0117 0.0138 lb/day 

VOC 

4-Ethyl-1,2-DimethylBenzene 0.00000429 0.0000214 0.0000171 lb/day 

VOC 4-Heptanone 0.0000795 0.000530 0.000265 lb/day 

VOC 4-Isopropyltoluene 0.000864 0.00187 0.00210 lb/day 

VOC 4-Methyl-2-Pentanone 0.000900 0.00182 0.00215 lb/day 

VOC Acetaldehyde 0.0183 0.0371 0.0436 lb/day 

VOC Acetone 0.133 0.271 0.316 lb/day 

VOC Acrolein 0.00764 0.0155 0.0183 lb/day 

VOC Benzaldehyde 0.000237 0.000474 0.000569 lb/day 

VOC Benzene 0.00719 0.0208 0.0182 lb/day 

VOC Benzocycloheptatriene 0.0363 0.0726 0.0871 lb/day 

G-22
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel Scenario 2 

Total Loading 

Rate Large 

Metropolitan 

Harbor 

Vessel 

Scenario 3 

Total Loading 

Rate 

Recreational 

Harbor 

Units 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

VOC Benzofuran 0.00368 0.00736 0.00883 lb/day 

VOC Bromodichloromethane 0.00000416 0.0000277 0.0000139 lb/day 

VOC Butane 0.000521 0.00347 0.00174 lb/day 

VOC Butyraldehyde 0.00448 0.00917 0.0107 lb/day 

VOC Carbon disulfide 0.00000279 0.00000559 0.00000671 lb/day 

VOC Chloroform 0.00244 0.00488 0.00585 lb/day 

VOC cis-1,2-Dichloroethene 0.00000430 0.00000860 0.0000103 lb/day 

VOC Cyclohexane 0.0000660 0.000439 0.000221 lb/day 

VOC Dibromochloromethane 0.00000408 0.0000272 0.0000136 lb/day 

VOC Dimethocxymethane 0.0156 0.0130 0.0117 lb/day 

VOC Ethanol 0.0000212 0.000142 0.0000708 lb/day 

VOC Ethylbenzene 0.00230 0.0114 0.00667 lb/day 

VOC Indene 0.0000735 0.000368 0.0000941 lb/day 

VOC Isopropylbenzene 0.00132 0.00323 0.00327 lb/day 

VOC Limonene 0.00 0.00 0.00 lb/day 

VOC 

m,p-Xylene (Sum of 

Isomers) 0.00728 0.0414 0.0224 lb/day 

VOC Methyl acetate 0.00190 0.00382 0.00457 lb/day 

VOC 

Methyl tertiary butyl ether 

(MTBE) 0.00000865 0.0000564 0.0000293 lb/day 

VOC Methylcyclohexane 0.0000599 0.000398 0.000200 lb/day 

VOC Methylene chloride 0.000477 0.00104 0.00115 lb/day 

VOC n-Butylbenzene 0.000819 0.00164 0.00197 lb/day 

VOC nitro-Methane 0.00272 0.00544 0.00653 lb/day 

VOC Nonanal 0.00000183 0.00000366 0.00000440 lb/day 

VOC n-Propylbenzene 0.000644 0.00313 0.00191 lb/day 

VOC n-Valeraldehyde 0.00397 0.00819 0.00943 lb/day 

VOC O-Xylene 0.00481 0.0267 0.0145 lb/day 

VOC sec-Butylbenzene 0.00186 0.00372 0.00446 lb/day 

VOC Styrene 0.00138 0.00368 0.00340 lb/day 

VOC Sulfur dioxide 0.00739 0.0385 0.00964 lb/day 

VOC Tetrachloroethene 0.00000345 0.00000789 0.00000776 lb/day 

VOC Toluene 0.00857 0.0417 0.0254 lb/day 

VOC Trichloroethene 0.00000301 0.00000602 0.00000722 lb/day 

VOC Trichlorofluoromethane 0.00158 0.00316 0.00379 lb/day 

VOC Tridecane 0.00325 0.00649 0.00779 lb/day 

VOC Unknown VOC 0.00379 0.00907 0.00939 lb/day 

VOC Unknown VOC (01) 0.00288 0.00597 0.00681 lb/day 

VOC Unknown VOC (02) 0.00382 0.00777 0.00910 lb/day 

VOC Unknown VOC (03) 0.00347 0.00707 0.00826 lb/day 

VOC Unknown VOC (04) 0.00228 0.00483 0.00535 lb/day 

VOC Unknown VOC (05) 0.00208 0.00434 0.00490 lb/day 

G-23
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel Scenario 2 

Total Loading 

Rate Large 

Metropolitan 

Harbor 

Vessel 

Scenario 3 

Total Loading 

Rate 

Recreational 

Harbor 

Units 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

VOC Vinyl acetate 0.00202 0.00407 0.00485 lb/day 

SVOC (E)-2-Tetradecene 0.000237 0.00118 0.000237 lb/day 

SVOC 

1,2,3,4-Tetrahydro-2,7-

Dimethylnaphthalene 0.000169 0.00112 0.000562 lb/day 

SVOC 

1,2,3-Trichloro-(Z)-1-

Propene 0.0000494 0.000330 0.000165 lb/day 

SVOC 1,2,3-Trimethylbenzene (1) 0.000719 0.00479 0.00240 lb/day 

SVOC 1,2,3-Trimethylbenzene (2) 0.000917 0.00611 0.00306 lb/day 

SVOC 

1,2,4,5-Tetramethylbenzene 

(1) 0.000101 0.000671 0.000336 lb/day 

SVOC 

1,2,4,5-Tetramethylbenzene 

(2) 0.0000934 0.000623 0.000311 lb/day 

SVOC 1,2-Diethyl-Cyclobutane 0.00930 0.0186 0.0223 lb/day 

SVOC 1,3-Dimethylnaphthalene 0.0000821 0.000411 0.0000821 lb/day 

SVOC 

1,3-Dimethylnaphthalene 

(01) 0.00527 0.0105 0.0127 lb/day 

SVOC 

1,4-Dimethyl-1,2,3,4-

tetrahydronaphthalene 0.00780 0.0156 0.0187 lb/day 

SVOC 1,4-Dimethylnaphthalene 0.00840 0.0185 0.0204 lb/day 

SVOC 

1,4-Dimethylnaphthalene 

(01) 0.00559 0.0112 0.0134 lb/day 

SVOC 1,5-Dimethylnaphthalene 0.000737 0.00461 0.00203 lb/day 

SVOC 1,6-Dimethylnaphthalene 0.0395 0.0792 0.0948 lb/day 

SVOC 

1,7,7-tri-(methyl)-

bicyclo[2.2.1]heptane 0.00 0.00 0.00 lb/day 

SVOC 1-Dodecanol 0.0000265 0.000177 0.0000884 lb/day 

SVOC 1-Hexadecene 0.00000246 0.0000164 0.00000819 lb/day 

SVOC 

1-Methyl-2-Propyl-Benzene 

(01) 0.000758 0.00506 0.00253 lb/day 

SVOC 

1-Methyl-2-Propyl-Benzene 

(02) 0.000219 0.00146 0.000730 lb/day 

SVOC 1-Methylnaphthalene 0.0358 0.0737 0.0857 lb/day 

SVOC 1-Phenyl-1-Butene 0.00000119 0.00000595 0.00000476 lb/day 

SVOC 2-(dodecyloxy)-Ethanol 0.0000331 0.000221 0.000110 lb/day 

SVOC 2-(hexadecyloxy)-Ethanol 0.00000851 0.0000567 0.0000284 lb/day 

SVOC 2-(tetradecyloxy)-Ethanol 0.0000246 0.000164 0.0000819 lb/day 

SVOC 2,3-Dimethylnaphthalene 0.00688 0.0138 0.0165 lb/day 

SVOC 2,4,6-Trichlorophenol 0.0000142 0.0000284 0.0000340 lb/day 

SVOC 2,4-Dimethyl-Benzaldehyde 0.00000221 0.0000111 0.00000886 lb/day 

SVOC 2,4-Dimethylphenol 0.00198 0.00405 0.00470 lb/day 

SVOC 

2,6,10,14-Tetramethyl 

Pentadecane 0.0124 0.0252 0.0294 lb/day 

SVOC 

2,6,10,14-

Tetramethylhexadecae 0.00826 0.0165 0.0198 lb/day 

G-24
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel Scenario 2 

Total Loading 

Rate Large 

Metropolitan 

Harbor 

Vessel 

Scenario 3 

Total Loading 

Rate 

Recreational 

Harbor 

Units 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

SVOC 

2,6,10,14-

Tetramethylhexadecae (01) 0.000267 0.00178 0.000890 lb/day 

SVOC 2,6-dimethyl-Heptadecane 0.0135 0.0270 0.0324 lb/day 

SVOC 2,7-Dimethylnaphthalene 0.00967 0.0206 0.0229 lb/day 

SVOC 2-Cyclopenten1-one 0.000929 0.00186 0.00223 lb/day 

SVOC 2-Ethyl-Hexanoic acid 0.0947 0.631 0.316 lb/day 

SVOC 2-Hydroxy-Benzaldehyde 0.0144 0.0292 0.0343 lb/day 

SVOC 2-Mercaptobenzothiazole 0.00 0.00 0.00 lb/day 

SVOC 2-Methyl Tridecane 0.000141 0.000942 0.000471 lb/day 

SVOC 2-Methyl-Benzaldehyde 0.00607 0.0122 0.0146 lb/day 

SVOC 2-Methyl-Dodecane 0.000117 0.000585 0.000117 lb/day 

SVOC 2-Methylnaphthalene 0.0458 0.0957 0.110 lb/day 

SVOC 

2-

Naphthalenecarboxaldehyde 0.00102 0.00203 0.00244 lb/day 

SVOC 3,4-Dimethylphenol 0.00000104 0.00000520 0.00000416 lb/day 

SVOC 3,5-Dimethyl-Benzaldehyde 0.00000135 0.00000673 0.00000538 lb/day 

SVOC 3,6-Dimethylundecane 0.00000205 0.0000102 0.00000171 lb/day 

SVOC 3-Methyl-Benzaldehyde 0.0129 0.0258 0.0310 lb/day 

SVOC 

3-Methyl-Benzaldehyde 

(01) 0.0145 0.0290 0.0347 lb/day 

SVOC 3-Methyl-butanoic acid 0.000448 0.000299 0.000280 lb/day 

SVOC 3-Methyl-Phenanthrene 0.00605 0.0121 0.0145 lb/day 

SVOC 3-Methylphenol 0.000677 0.00135 0.00163 lb/day 

SVOC 3-Phenyl-2-Propenal 0.000457 0.000914 0.00110 lb/day 

SVOC 4,4-Dimethylbiphenyl 0.00629 0.0126 0.0151 lb/day 

SVOC 4-Hydroxy-2-Butanone 0.00705 0.0141 0.0169 lb/day 

SVOC 4-Methyl-1H-Benzotriazole 0.00000709 0.0000142 0.0000170 lb/day 

SVOC 

4-METHYL-PENTANOIC 

ACID 0.000299 0.000199 0.000187 lb/day 

SVOC 5-Butyl-Hexadecane 0.00000158 0.00000789 0.00000131 lb/day 

SVOC 

5-Methyl-2-(1-methyl)-

Cyclohexanol 0.00000694 0.0000462 0.0000231 lb/day 

SVOC 9-Methyl-9H-Fluorene 0.00648 0.0130 0.0155 lb/day 

SVOC Acenaphthylene 0.00351 0.00707 0.00841 lb/day 

SVOC Acetophenone 0.0000444 0.000222 0.0000444 lb/day 

SVOC Benzeneacetic Acid 0.000228 0.000152 0.000142 lb/day 

SVOC Benzenepropanoic Acid 0.000251 0.000168 0.000157 lb/day 

SVOC Benzothiazole 0.0000293 0.0000712 0.0000728 lb/day 

SVOC Benzyl alcohol 0.0000464 0.000232 0.0000464 lb/day 

SVOC Biphenyl 0.00353 0.00767 0.00832 lb/day 

SVOC Bis(2-ethylhexyl) phthalate 0.00148 0.00362 0.00347 lb/day 

SVOC Caprolactam 0.0000250 0.000167 0.0000834 lb/day 

G-25
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel Scenario 2 

Total Loading 

Rate Large 

Metropolitan 

Harbor 

Vessel 

Scenario 3 

Total Loading 

Rate 

Recreational 

Harbor 

Units 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

SVOC Cholesterol 0.000691 0.000461 0.000432 lb/day 

SVOC Cyclic octaatomic sulfur 0.0223 0.122 0.0366 lb/day 

SVOC Cyclodecane 0.000242 0.00121 0.000242 lb/day 

SVOC Cyclododecane 0.0000275 0.000182 0.0000903 lb/day 

SVOC Cyclotetradecane 0.0000145 0.0000967 0.0000484 lb/day 

SVOC 

Diethene Glycol 

Monododecyl Ether 0.0000273 0.000182 0.0000911 lb/day 

SVOC Dimethyl phthalate 0.0000827 0.000165 0.000199 lb/day 

SVOC Di-n-butyl phthalate 0.00182 0.00409 0.00424 lb/day 

SVOC Di-n-octyl phthalate 0.0000528 0.000344 0.000174 lb/day 

SVOC Disopropylene glycol 0.00000806 0.0000538 0.0000269 lb/day 

SVOC Dodecane 0.00000118 0.00000589 0.000000981 lb/day 

SVOC Dodecanoic acid 0.0000198 0.000132 0.0000661 lb/day 

SVOC Eicosane 0.0307 0.0638 0.0742 lb/day 

SVOC Ethanol, 2,2-oxybis- 0.000892 0.00595 0.00297 lb/day 

SVOC Ethanol, 2-Butoxy 0.00787 0.0157 0.0189 lb/day 

SVOC Fluorene 0.00374 0.00755 0.00896 lb/day 

SVOC Heneicosane 0.00918 0.0217 0.0227 lb/day 

SVOC Heptadecane 0.0548 0.111 0.131 lb/day 

SVOC 

Hexaethylene Glycol 

Monododecyl 0.0000166 0.000111 0.0000555 lb/day 

SVOC 

Hexaethylene Glycol 

Monododecyl (01) 0.00000667 0.0000444 0.0000222 lb/day 

SVOC 

Hexaethylene Glycol 

Monododecyl (02) 0.00000210 0.0000140 0.00000702 lb/day 

SVOC Hexagol 0.00000960 0.0000640 0.0000320 lb/day 

SVOC Indane 0.000785 0.00523 0.00262 lb/day 

SVOC Indole 0.00126 0.000838 0.000786 lb/day 

SVOC 

Isopropylbenzene-4,methyl1 0.00 0.00 0.00 lb/day 

SVOC m-Cresol 0.0000717 0.000358 0.0000748 lb/day 

SVOC Naphthalene 0.0167 0.0395 0.0405 lb/day 

SVOC 

N-ButylBenzenesulfonamide 0.00000275 0.0000183 0.00000915 lb/day 

SVOC n-Hexadecane 0.0521 0.105 0.125 lb/day 

SVOC n-Hexadecanoic acid 0.0000140 0.0000935 0.0000468 lb/day 

SVOC Nonadecane 0.0421 0.0849 0.101 lb/day 

SVOC Nonadecane (01) 0.0130 0.0260 0.0312 lb/day 

SVOC Nonanoic Acid 0.0102 0.0205 0.0246 lb/day 

SVOC n-Pentadecane 0.0389 0.0952 0.0963 lb/day 

SVOC n-Tetradecane 0.0490 0.109 0.119 lb/day 

SVOC o-Cresol 0.00581 0.0116 0.0139 lb/day 

SVOC Octadecane 0.0118 0.0237 0.0284 lb/day 

G-26
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

G-27

Appendix G.3: Vessel Scenario Total Analyte-Specific Loading Rates 

Analyte 

Class Analyte 

Vessel 

Scenario 1 

Total Loading 

Rate Fishing 

Harbor 

Vessel Scenario 2 

Total Loading 

Rate Large 

Metropolitan 

Harbor 

Vessel 

Scenario 3 

Total Loading 

Rate 

Recreational 

Harbor 

Units 

SVOC p-Cresol 0.0175 0.0365 0.0416 lb/day 

SVOC Pentacosane 0.000243 0.00162 0.000811 lb/day 

SVOC 

Pentaethene Glycol 

Monododecyl Ether 0.00000225 0.0000150 0.00000750 lb/day 

SVOC 

Pentaethene Glycol 

Monododecyl Ether (01) 0.0000164 0.000110 0.0000548 lb/day 

SVOC 

Pentaethene Glycol 

Monododecyl Ether (02) 0.0000324 0.000216 0.000108 lb/day 

SVOC Phenanthrene 0.00319 0.00790 0.00762 lb/day 

SVOC Phenol 0.0365 0.0737 0.0853 lb/day 

SVOC 

Phthalic acid, isobutyl octyl 

ester 0.0000130 0.0000260 0.0000312 lb/day 

SVOC Pyrene 0.000119 0.000783 0.000381 lb/day 

SVOC Sulfur 0.0101 0.0510 0.0106 lb/day 

SVOC 

Tetraethylene glycol 

monododecyl ether 0.0000168 0.000112 0.0000559 lb/day 

SVOC Triethyl phosphate 0.000170 0.000130 0.000129 lb/day 

SVOC 

Triethylene glycol 

monododecyl ether 0.0000249 0.000166 0.0000830 lb/day 

SVOC Unknown SVOC 0.00970 0.0212 0.0226 lb/day 

SVOC Unknown SVOC (01) 0.00893 0.0205 0.0208 lb/day 

SVOC Unknown SVOC (02) 0.00957 0.0222 0.0220 lb/day 

SVOC Unknown SVOC (03) 0.000681 0.00327 0.000879 lb/day 

SVOC Unknown SVOC (04) 0.000637 0.00337 0.000902 lb/day 

SVOC Unknown SVOC (05) 0.000188 0.00117 0.000508 lb/day 

SVOC Unknown SVOC (06) 0.000124 0.000758 0.000315 lb/day 

SVOC Unknown SVOC (07) 0.00141 0.00940 0.00470 lb/day 

(1) EPA suspects a limited number of the samples analyzed for selenium (even fewer for arsenic) for bilgewater, 

packing gland effluent, propulsion engine effluent, graywater and deck washdown water may be positively 

influenced (increased) by interference from high concentrations of major cations in the sample matrix. Although 

EPA suspects that the highest concentrations of dissolved arsenic (and to a lesser extent selenium) in fish hold 

effluent from a shrimping vessel could be slightly elevated due to cation interference; EPA believes the fish hold 

concentrations reasonably represent true effluent concentrations for the discharge (see Section 3.2.4.1). EPA 

considered these interferences when interpreting the potential for vessel discharges to pose a risk to human health, 

aquatic life, or the environment and determined that such cationic interference does not influence the major findings 

presented in the modeling analysis. 
Appendix G – Supporting Information for EPA’s Screenin

Appendix G.4: Real World Water Body Characterization Data for Model Input Parameter Dev

Harbor 

Name River Name City Name Harbor Salinity (PSU)a Ocean Salinity (PSU)b Harbor Volume (m3)c River Flow (m3/day)d fx Flushing Time (days) Scena

1 Diluti

Auke Bay Mendenhall River Juneau, AK 26.1 35 3,090,000 2,900,000 0.254 0.271 5,8Biscayne Bay Miami River Miami, FL 31 35 38,500,000 352,000 0.114 12.5 1,5Cohasset Harbor Gulf River Boston, MA 30.8 35 1,170,000 89,800 0.121 1.59 3Craford Bay 

Eastern and Southern Branch Elizabeth River 

Norfolk, VA 19.8 35 1,660,000 384,000 0.434 1.87 4

Dorchester Bay Neponset River Boston, MA 31.1 35 43,300,000 467,000 0.111 10.3 2,1Eastern Channel Indian River Sitka, AK 30.8 35 8,500,000 210,000 0.12 4.84 8Mobile Bay Tensaw, Blakeley, and Mobile River Mobile, AL 16.7 35 1,970,000,000 167,000,000 0.523 6.16 163,0Yaquina Bay Yaquina River Newport, OR 29.3 35 6,880,000 2,060,000 0.163 0.544 6,4a Sources: NOAA World Oceans Database (Auke Bay, Dorchester Bay, Eastern Channel, and Mobile Bay), USGS Changing Salinity P

Florida Study (Biscayne Bay), Massachusetts Department of Environmental Protection Total Maximum Daily Loads of Bacteria for LitHarbor), EPA EMAP Salinity Data (Craford Bay), Oregon State Temperature and Salinity of the Yaquina Bay Estuary and the Potentia

maenas Study (Yaquina Bay). 

b Ocean salinity based on average ocean salinity of 35 PSU. c Harbor volume was estimated based on surface areas and harbor depths estimated from NOAA Booklet Charts (http://ocsdata.ncd.noa

accessed 7/28/2009. 

d River flows were based on average annual flows estimated in the USGS NHD Plus GIS dataset. Alaska average annual rivers flows w

based USGS surface-water monthly statistics for site USGS 15052500 and USGS 15087700 available in the USGS National Water Info

G-28
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.5: Fishing Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

1 and 3 

Model 

Scenarios

2 and 4 

Model 

Scenarios 

5 and 7 

Model 

Scenarios 

6 and 8 

Units 

Bacteria E. Coli by MF 0.64 0.0777 0.288 0.0349 

CFU/100 

ml 

Bacteria E. Coli by MPN 0.258 0.0313 0.116 0.0141 

MPN/100 

ml 

Bacteria Enterococci by MF 0.361 0.0438 0.162 0.0197 

CFU/100 

ml 

Bacteria Enterococci by MPN 0.0733 0.0089 0.0329 0.004 

MPN/100 

ml 

Bacteria Fecal Coliform by MF 1.96 0.238 0.883 0.107 

CFU/100 

ml 

Bacteria Fecal Coliform by MPN 0.722 0.0877 0.325 0.0394 

MPN/100 

ml 

Bacteria Total Coliforms by MPN 3.1 0.376 1.39 0.169 

MPN/100 

ml 

Classicals Biochemical Oxygen Demand (BOD) 0.208 0.0252 0.0935 0.0113 mg/l 

Classicals Chemical Oxygen Demand (COD) 0.604 0.0733 0.271 0.0329 mg/l 

Classicals Dissolved Oxygen 0.00838 0.00102 0.00377 0.000457 mg/l 

Classicals Hexane Extractable Material (HEM) 0.00373 0.000452 0.00167 0.000203 mg/l 

Classicals Silica Gel Treated HEM (SGT-HEM) 0.00432 0.000525 0.00194 0.000236 mg/l 

Classicals Sulfide 0.00000497 6.03E-07 0.00000223 2.71E-07 mg/l 

Classicals Total Organic Carbon (TOC) 0.0783 0.0095 0.0352 0.00427 mg/l 

Classicals Total Residual Chlorine 0.000132 0.000016 0.0000593 0.0000072 mg/l 

Classicals Total Suspended Solids (TSS) 0.0758 0.0092 0.0341 0.00413 mg/l 

Nutrients Ammonia As Nitrogen (NH3-N) 0.00279 0.000339 0.00125 0.000152 mg/l 

Nutrients Nitrate/Nitrite (NO3/NO2-N) 0.0000415 0.00000504 0.0000187 0.00000226 mg/l 

Nutrients Total Kjeldahl Nitrogen (TKN) 0.0321 0.00389 0.0144 0.00175 mg/l 

Nutrients Total Phosphorus 0.00451 0.000547 0.00203 0.000246 mg/l 

Metals Aluminum, Dissolved 0.658 0.0798 0.296 0.0359 μg/l 

Metals Aluminum, Total 0.835 0.101 0.375 0.0455 μg/l 

Metals Antimony, Dissolved 0.00000712 8.65E-07 0.0000032 3.89E-07 μg/l 

Metals Antimony, Total 0.0000233 0.00000283 0.0000105 0.00000127 μg/l 

Metals Arsenic, Dissolved 1 0.00624 0.000758 0.00281 0.00034 μg/l 

Metals Arsenic, Total 1 0.00913 0.00111 0.0041 0.000498 μg/l 

Metals Barium, Dissolved 0.0107 0.0013 0.0048 0.000582 μg/l 

Metals Barium, Total 0.0121 0.00146 0.00542 0.000658 μg/l 

Metals Cadmium, Dissolved 0.00000963 0.00000117 0.00000433 5.25E-07 μg/l 

Metals Cadmium, Total 0.000246 0.0000298 0.00011 0.0000134 μg/l 

Metals Calcium, Dissolved 214 26 96.2 11.7 μg/l 

Metals Calcium, Total 212 25.7 95.3 11.6 μg/l 

Metals Chromium, Dissolved 0.000639 0.0000775 0.000287 0.0000348 μg/l 

Metals Chromium, Total 0.00168 0.000204 0.000757 0.0000919 μg/l 

Metals Cobalt, Dissolved 0.0000244 0.00000296 0.000011 0.00000133 μg/l 

Metals Cobalt, Total 0.0000484 0.00000588 0.0000218 0.00000264 μg/l 

Metals Copper, Dissolved 0.942 0.114 0.423 0.0514 μg/l 

Metals Copper, Total 0.0518 0.00629 0.0233 0.00283 μg/l 

Metals Iron, Dissolved 0.00528 0.000641 0.00237 0.000288 μg/l 

Metals Iron, Total 0.123 0.015 0.0554 0.00672 μg/l 

G-29
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.5: Fishing Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Model Model Model Model 

Class Analyte Scenarios 

1 and 3 

Scenarios

2 and 4 

Scenarios 

5 and 7 

Scenarios Units 

6 and 8 

Metals Lead, Dissolved 0.000578 0.0000701 0.00026 0.0000315 μg/l 

Metals Lead, Total 0.00353 0.000429 0.00159 0.000193 μg/l 

Metals Magnesium, Dissolved 649 78.8 292 35.4 μg/l 

Metals Magnesium, Total 625 75.9 281 34.1 μg/l 

Metals Manganese, Dissolved 0.0392 0.00476 0.0176 0.00214 μg/l 

Metals Manganese, Total 0.0485 0.00588 0.0218 0.00264 μg/l 

Metals Nickel, Dissolved 0.0028 0.00034 0.00126 0.000153 μg/l 

Metals Nickel, Total 0.00323 0.000392 0.00145 0.000176 μg/l 

Metals Potassium, Dissolved 18.3 2.23 8.24 1 μg/l 

Metals Potassium, Total 18.4 2.23 8.26 1 μg/l 

Metals Selenium, Dissolved 1 0.00704 0.000854 0.00316 0.000384 μg/l 

Metals Selenium, Total 1 0.00801 0.000972 0.0036 0.000437 μg/l 

Metals Silver, Dissolved 0.00000904 0.0000011 0.00000406 4.93E-07 μg/l 

Metals Silver, Total 0.000017 0.00000206 0.00000764 9.27E-07 μg/l 

Metals Sodium, Dissolved 405 49.1 182 22.1 μg/l 

Metals Sodium,Total 473 57.4 213 25.8 μg/l 

Metals Thallium, Dissolved 0.00000472 5.73E-07 0.00000212 2.58E-07 μg/l 

Metals Thallium,Total 5.14E-08 6.24E-09 2.31E-08 2.81E-09 μg/l 

Metals Vanadium, Dissolved 0.000331 0.0000402 0.000149 0.0000181 μg/l 

Metals Vanadium,Total 0.000425 0.0000516 0.000191 0.0000232 μg/l 

Metals Zinc, Dissolved 0.101 0.0123 0.0456 0.00553 μg/l 

Metals Zinc, Total 0.248 0.0301 0.112 0.0135 μg/l 

Nonylphenols Bisphenol A 0.0000029 3.52E-07 0.00000131 1.58E-07 μg/l 

Nonylphenols Nonylphenol decaethoxylate (NP10EO) 0.000627 0.0000761 0.000282 0.0000342 μg/l 

Nonylphenols 

Nonylphenol dodecaethoxylate 

(NP12EO) 0.000499 0.0000605 0.000224 0.0000272 μg/l 

Nonylphenols 

Nonylphenol heptadecaethoxylate 

(NP17EO) 0.0000313 0.0000038 0.0000141 0.00000171 μg/l 

Nonylphenols Nonylphenol heptaethoxylate (NP7EO) 0.000401 0.0000486 0.00018 0.0000218 μg/l 

Nonylphenols 

Nonylphenol hexadecaethoxylate 

(NP16EO) 0.0000684 0.0000083 0.0000307 0.00000373 μg/l 

Nonylphenols Nonylphenol hexaethoxylate (NP6EO) 0.000284 0.0000344 0.000127 0.0000155 μg/l 

Nonylphenols Nonylphenol nonaethoxylate (NP9EO) 0.000566 0.0000687 0.000254 0.0000309 μg/l 

Nonylphenols Nonylphenol octaethoxylate (NP8EO) 0.000521 0.0000632 0.000234 0.0000284 μg/l 

Nonylphenols 

Nonylphenol octodecaethoxylate 

(NP18EO) 0.0000165 0.00000201 0.00000743 9.02E-07 μg/l 

Nonylphenols 

Nonylphenol pendecaethoxylate 

(NP15EO) 0.00013 0.0000158 0.0000586 0.00000711 μg/l 

Nonylphenols Nonylphenol pentaethoxylate (NP5EO) 0.000172 0.0000209 0.0000773 0.00000938 μg/l 

Nonylphenols 

Nonylphenol tetradecaethoxylate 

(NP14EO) 0.000232 0.0000282 0.000104 0.0000127 μg/l 

Nonylphenols Nonylphenol tetraethoxylate (NP4EO) 0.0000763 0.00000926 0.0000343 0.00000416 μg/l 

Nonylphenols 

Nonylphenol tridecaethoxylate 

(NP13EO) 0.000356 0.0000432 0.00016 0.0000194 μg/l 

Nonylphenols Nonylphenol triethoxylate (NP3EO) 0.000043 0.00000522 0.0000193 0.00000235 μg/l 

Nonylphenols 

Nonylphenol undecaethoxylate 

(NP11EO) 0.000637 0.0000774 0.000286 0.0000348 μg/l 

Nonylphenols Octylphenol decaethoxylate (OP10EO) 0.0000226 0.00000275 0.0000102 0.00000123 μg/l 

G-30
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.5: Fishing Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Model Model Model Model 

Class Analyte Scenarios 

1 and 3 

Scenarios

2 and 4 

Scenarios 

5 and 7 

Scenarios Units 

6 and 8 

Nonylphenols Octylphenol dodecaethoxylate (OP12EO) 0.0000135 0.00000164 0.00000608 7.38E-07 μg/l 

Nonylphenols Octylphenol heptaethoxylate (OP7EO) 0.000000989 0.00000012 4.44E-07 5.39E-08 μg/l 

Nonylphenols Octylphenol nonaethoxylate (OP9EO) 0.0000137 0.00000166 0.00000615 7.47E-07 μg/l 

Nonylphenols Octylphenol octaethoxylate (OP8EO) 0.00000843 0.00000102 0.00000379 0.00000046 μg/l 

Nonylphenols Octylphenol undecaethoxylate (OP11EO) 0.0000146 0.00000177 0.00000655 7.95E-07 μg/l 

Nonylphenols Total Nonylphenol Polyethoxylates 0.00445 0.000541 0.002 0.000243 μg/l 

Nonylphenols Total Nonylphenols 0.00005 0.00000607 0.0000225 0.00000273 μg/l 

VOC (2-Methyl-1-Propenyl)-Benzene 0.000975 0.000118 0.000438 0.0000532 μg/l 

VOC (E)-1-Propenyl-Benzene 0.000000442 5.37E-08 1.99E-07 2.41E-08 μg/l 

VOC (E)-2-Butenal 0.00178 0.000217 0.000802 0.0000973 μg/l 

VOC 1,2,3,4-Tetrahydro-1-Methylnaphthalene 0.00112 0.000136 0.000504 0.0000612 μg/l 

VOC 1,2,3,4-Tetrahydro-2-Methylnaphthalene 0.00103 0.000126 0.000465 0.0000565 μg/l 

VOC 1,2,3,4-Tetrahydro-5-Methylnaphthalene 0.00908 0.0011 0.00408 0.000495 μg/l 

VOC 1,2,3,4-Tetrahydro-6-Ethylnaphthalene, 0.000977 0.000119 0.000439 0.0000533 μg/l 

VOC 1,2,3,4-Tetrahydro-6-Methylnaphthalene 0.00828 0.001 0.00372 0.000451 μg/l 

VOC 

1,2,3,4-Tetrahydro-6-Methylnaphthalene 

(01) 0.00208 0.000252 0.000933 0.000113 μg/l 

VOC 

1,2,3,4-Tetrahydro-6-Methylnaphthalene 

(02) 0.00174 0.000211 0.00078 0.0000947 μg/l 

VOC 1,2,3,4-Tetrahydronaphthalene 0.00623 0.000756 0.0028 0.00034 μg/l 

VOC 1,2,3,4-Tetramethyl-Benzene 0.000211 0.0000256 0.0000947 0.0000115 μg/l 

VOC 1,2,3,5-Tetramethyl-Benzene 0.00031 0.0000376 0.000139 0.0000169 μg/l 

VOC 1,2,3-Trimethylbenzene 0.00101 0.000123 0.000455 0.0000552 μg/l 

VOC 1,2,4,5-Tetramethylbenzene 0.000473 0.0000574 0.000213 0.0000258 μg/l 

VOC 1,2,4-Trimethylbenzene 0.00202 0.000245 0.000907 0.00011 μg/l 

VOC 1,3,5-Trimethylbenzene 0.000545 0.0000662 0.000245 0.0000297 μg/l 

VOC 1,3-Methylnaphthalene 0.00128 0.000155 0.000575 0.0000698 μg/l 

VOC 1,7-Methylnaphthalene 0.00579 0.000703 0.0026 0.000316 μg/l 

VOC 1-Ethyl-2,3-Dimethyl-Benzene (01) 0.000892 0.000108 0.000401 0.0000487 μg/l 

VOC 1-Ethyl-2,3-Dimethyl-Benzene (02) 0.000129 0.0000156 0.0000579 0.00000703 μg/l 

VOC 1-Ethyl-2,4-Dimethyl-Benzene 0.000501 0.0000608 0.000225 0.0000273 μg/l 

VOC 1-Ethyl-2-Methyl-Benzene 0.00000137 1.66E-07 6.14E-07 7.45E-08 μg/l 

VOC 1-Ethyl-3-Methyl-Benzene 0.00107 0.00013 0.000482 0.0000585 μg/l 

VOC 1-Ethyl-4-Methyl-Benzene 0.00211 0.000256 0.000949 0.000115 μg/l 

VOC 1-Methyl-2-(1-Methylethyl)-Benzene 0 0 0 0 μg/l 

VOC 

1-Methyl-2-(1-Methylethyl)-Benzene 

(01) 0.00000111 1.34E-07 4.97E-07 6.03E-08 μg/l 

VOC 

1-Methyl-2-(1-Methylethyl)-Benzene 

(02) 0.00000386 4.69E-07 0.00000174 2.11E-07 μg/l 

VOC 1-Methyl-3-Propyl-Benzene 0.000411 0.0000499 0.000185 0.0000224 μg/l 

VOC 

1-Methyl-4-(1-Methylidene)-

Cyclohexane 0 0 0 0 μg/l 

VOC 1-methyl-Indan 0.0026 0.000315 0.00117 0.000142 μg/l 

VOC 1-Propenyl-Benzene 0.000000507 6.16E-08 2.28E-07 2.77E-08 μg/l 

VOC 2- Heptanone 0.0000197 0.00000239 0.00000885 0.00000107 μg/l 

VOC 2,3-Dihydro-1,2-Dimethyl-1H-Indene 0.000106 0.0000129 0.0000476 0.00000578 μg/l 

G-31
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.5: Fishing Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

1 and 3 

Model 

Scenarios 

5 and 7 

Model 

Scenarios 

6 and 8 

Units 

Model 

Scenarios

2 and 4 

VOC 2,3-Dihydro-1,6-Dimethyl-1H-Indene 0.00117 0.000141 0.000524 0.0000636 μg/l 

VOC 2,3-Dihydro-1-Methylindene 0.0017 0.000206 0.000763 0.0000926 μg/l 

VOC 2,3-Dihydro-1-methylindene (01) 0.000949 0.000115 0.000426 0.0000518 μg/l 

VOC 2,3-Dihydro-1-methylindene (02) 0.00201 0.000244 0.000904 0.00011 μg/l 

VOC 2,3-Dihydro-4,7-Dimethyl-1H-Indene 0.0000134 0.00000163 0.00000602 7.31E-07 μg/l 

VOC 2,3-Dihydro-4-Methyl-1H-Indene 0.0179 0.00217 0.00804 0.000975 μg/l 

VOC 2,3-Dihydro-4-Methyl-1H-Indene (01) 0.00000157 1.91E-07 7.07E-07 8.58E-08 μg/l 

VOC 2,3-Dihydro-4-Methyl-1H-Indene (02) 0.00000265 3.22E-07 0.00000119 1.45E-07 μg/l 

VOC 2,3-Dihydro-5,6-dimethyl-1H-Indene 0.00092 0.000112 0.000413 0.0000502 μg/l 

VOC 2,3-Dihydro-5-methyl-1H-Indene 0.000521 0.0000632 0.000234 0.0000284 μg/l 

VOC 2,6-Dimethylnaphthalene 0.0126 0.00153 0.00566 0.000687 μg/l 

VOC 2-Butanone 0.00974 0.00118 0.00438 0.000531 μg/l 

VOC 2-Butenal 0.00111 0.000135 0.0005 0.0000607 μg/l 

VOC 2-Ethyl-1,3,5-Trimethyl-Benzene 0.00134 0.000163 0.000603 0.0000732 μg/l 

VOC 2-Ethyl-1,4-Dimethyl-Benzene 0.0062 0.000753 0.00279 0.000338 μg/l 

VOC 2-Ethyl-1-Hexanol 0.000000364 4.42E-08 1.64E-07 1.99E-08 μg/l 

VOC 2-Ethyltoluene 0.00177 0.000215 0.000797 0.0000968 μg/l 

VOC 2-Hexanone 0.000857 0.000104 0.000385 0.0000468 μg/l 

VOC 2-Methyl-2-Propenal 0.00207 0.000251 0.000931 0.000113 μg/l 

VOC 2-Propenyl-Benzene 0.00154 0.000187 0.000693 0.0000842 μg/l 

VOC 3-Buten-2-one 0.00189 0.00023 0.000851 0.000103 μg/l 

VOC 4-Ethyl-1,2-Dimethyl-Benzene 0.0000014 0.00000017 6.31E-07 7.66E-08 μg/l 

VOC 4-Heptanone 0.000026 0.00000316 0.0000117 0.00000142 μg/l 

VOC 4-Isopropyltoluene 0.000283 0.0000344 0.000127 0.0000155 μg/l 

VOC 4-Methyl-2-Pentanone 0.000295 0.0000358 0.000132 0.0000161 μg/l 

VOC Acetaldehyde 0.00599 0.000727 0.00269 0.000327 μg/l 

VOC Acetone 0.0435 0.00528 0.0195 0.00237 μg/l 

VOC Acrolein 0.0025 0.000304 0.00113 0.000137 μg/l 

VOC Benzaldehyde 0.0000777 0.00000943 0.0000349 0.00000424 μg/l 

VOC Benzene 0.00236 0.000286 0.00106 0.000129 μg/l 

VOC Benzocycloheptatriene 0.0119 0.00144 0.00534 0.000648 μg/l 

VOC Benzofuran 0.00121 0.000146 0.000542 0.0000658 μg/l 

VOC Bromodichloromethane 0.00000136 1.65E-07 6.12E-07 7.43E-08 μg/l 

VOC Butane 0.000171 0.0000207 0.0000768 0.00000932 μg/l 

VOC Butyraldehyde 0.00147 0.000178 0.00066 0.0000801 μg/l 

VOC Carbon disulfide 0.000000916 1.11E-07 4.12E-07 0.00000005 μg/l 

VOC Chloroform 0.000799 0.000097 0.000359 0.0000436 μg/l 

VOC cis-1,2-Dichloroethene 0.00000141 1.71E-07 6.33E-07 7.68E-08 μg/l 

VOC Cyclohexane 0.0000216 0.00000263 0.00000973 0.00000118 μg/l 

VOC Dibromochloromethane 0.00000134 1.62E-07 6.01E-07 7.29E-08 μg/l 

VOC Dimethocxymethane 0.00512 0.000621 0.0023 0.000279 μg/l 

VOC Ethanol 0.00000696 8.45E-07 0.00000313 0.00000038 μg/l 

VOC Ethylbenzene 0.000754 0.0000916 0.000339 0.0000411 μg/l 

G-32
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.5: Fishing Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

1 and 3 

Model 

Scenarios

2 and 4 

Model 

Scenarios 

5 and 7 

Model 

Scenarios 

6 and 8 

Units 

VOC Indene 0.0000241 0.00000292 0.0000108 0.00000131 μg/l 

VOC Isopropylbenzene 0.000431 0.0000523 0.000194 0.0000235 μg/l 

VOC Limonene 0 0 0 0 μg/l 

VOC m,p-Xylene (Sum of Isomers) 0.00239 0.00029 0.00107 0.00013 μg/l 

VOC Methyl acetate 0.000624 0.0000757 0.00028 0.000034 μg/l 

VOC Methyl tertiary butyl ether (MTBE) 0.00000283 3.44E-07 0.00000127 1.55E-07 μg/l 

VOC Methylcyclohexane 0.0000196 0.00000238 0.00000883 0.00000107 μg/l 

VOC Methylene chloride 0.000156 0.000019 0.0000703 0.00000853 μg/l 

VOC n-Butylbenzene 0.000268 0.0000326 0.000121 0.0000146 μg/l 

VOC nitro-Methane 0.000891 0.000108 0.000401 0.0000486 μg/l 

VOC Nonanal 0.0000006 7.28E-08 0.00000027 3.27E-08 μg/l 

VOC n-Propylbenzene 0.000211 0.0000256 0.0000949 0.0000115 μg/l 

VOC n-Valeraldehyde 0.0013 0.000158 0.000585 0.000071 μg/l 

VOC O-Xylene 0.00158 0.000191 0.000708 0.000086 μg/l 

VOC sec-Butylbenzene 0.000609 0.0000739 0.000274 0.0000332 μg/l 

VOC Styrene 0.000451 0.0000548 0.000203 0.0000246 μg/l 

VOC Sulfur dioxide 0.00242 0.000294 0.00109 0.000132 μg/l 

VOC Tetrachloroethene 0.00000113 1.37E-07 5.08E-07 6.17E-08 μg/l 

VOC Toluene 0.00281 0.000341 0.00126 0.000153 μg/l 

VOC Trichloroethene 0.000000986 0.00000012 4.43E-07 5.38E-08 μg/l 

VOC Trichlorofluoromethane 0.000518 0.0000628 0.000233 0.0000282 μg/l 

VOC Tridecane 0.00106 0.000129 0.000478 0.000058 μg/l 

VOC Unknown VOC 0.00124 0.000151 0.000558 0.0000677 μg/l 

VOC Unknown VOC (01) 0.000943 0.000114 0.000424 0.0000515 μg/l 

VOC Unknown VOC (02) 0.00125 0.000152 0.000562 0.0000682 μg/l 

VOC Unknown VOC (03) 0.00114 0.000138 0.000511 0.000062 μg/l 

VOC Unknown VOC (04) 0.000748 0.0000908 0.000336 0.0000408 μg/l 

VOC Unknown VOC (05) 0.000681 0.0000827 0.000306 0.0000372 μg/l 

VOC Vinyl acetate 0.000663 0.0000805 0.000298 0.0000362 μg/l 

SVOC (E)-2-Tetradecene 0.0000776 0.00000942 0.0000349 0.00000423 μg/l 

SVOC 

1,2,3,4-Tetrahydro-2,7-

Dimethylnaphthalene 0.0000553 0.00000671 0.0000248 0.00000302 μg/l 

SVOC 1,2,3-Trichloro-(Z)-1-Propene 0.0000162 0.00000197 0.00000728 8.84E-07 μg/l 

SVOC 1,2,3-Trimethylbenzene (1) 0.000236 0.0000286 0.000106 0.0000129 μg/l 

SVOC 1,2,3-Trimethylbenzene (2) 0.0003 0.0000365 0.000135 0.0000164 μg/l 

SVOC 1,2,4,5-Tetramethylbenzene (1) 0.000033 0.00000401 0.0000148 0.0000018 μg/l 

SVOC 1,2,4,5-Tetramethylbenzene (2) 0.0000306 0.00000372 0.0000138 0.00000167 μg/l 

SVOC 1,2-Diethyl-Cyclobutane 0.00305 0.00037 0.00137 0.000166 μg/l 

SVOC 1,3-Dimethylnaphthalene 0.0000269 0.00000327 0.0000121 0.00000147 μg/l 

SVOC 1,3-Dimethylnaphthalene (01) 0.00173 0.00021 0.000777 0.0000943 μg/l 

SVOC 

1,4-Dimethyl-1,2,3,4-

tetrahydronaphthalene 0.00256 0.00031 0.00115 0.000139 μg/l 

SVOC 1,4-Dimethylnaphthalene 0.00275 0.000334 0.00124 0.00015 μg/l 

SVOC 1,4-Dimethylnaphthalene (01) 0.00183 0.000222 0.000823 0.0000999 μg/l 

G-33
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.5: Fishing Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

1 and 3 

Model 

Scenarios

2 and 4 

Model 

Scenarios 

5 and 7 

Model 

Scenarios 

6 and 8 

Units 

SVOC 1,5-Dimethylnaphthalene 0.000241 0.0000293 0.000109 0.0000132 μg/l 

SVOC 1,6-Dimethylnaphthalene 0.013 0.00157 0.00582 0.000707 μg/l 

SVOC 1,7,7-tri-(methyl)-bicyclo[2.2.1]heptane 0 0 0 0 μg/l 

SVOC 1-Dodecanol 0.00000869 0.00000105 0.0000039 4.74E-07 μg/l 

SVOC 1-Hexadecene 0.000000805 9.77E-08 3.62E-07 4.39E-08 μg/l 

SVOC 1-Methyl-2-Propyl-Benzene (01) 0.000249 0.0000302 0.000112 0.0000136 μg/l 

SVOC 1-Methyl-2-Propyl-Benzene (02) 0.0000718 0.00000871 0.0000323 0.00000392 μg/l 

SVOC 1-Methylnaphthalene 0.0117 0.00142 0.00527 0.00064 μg/l 

SVOC 1-Phenyl-1-Butene 0.00000039 4.73E-08 1.75E-07 2.13E-08 μg/l 

SVOC 2-(dodecyloxy)-Ethanol 0.0000109 0.00000132 0.00000488 5.92E-07 μg/l 

SVOC 2-(hexadecyloxy)-Ethanol 0.00000279 3.38E-07 0.00000125 1.52E-07 μg/l 

SVOC 2-(tetradecyloxy)-Ethanol 0.00000805 9.77E-07 0.00000362 4.39E-07 μg/l 

SVOC 2,3-Dimethylnaphthalene 0.00225 0.000274 0.00101 0.000123 μg/l 

SVOC 2,4,6-Trichlorophenol 0.00000465 5.64E-07 0.00000209 2.53E-07 μg/l 

SVOC 2,4-Dimethyl-Benzaldehyde 0.000000726 8.81E-08 3.26E-07 3.96E-08 μg/l 

SVOC 2,4-Dimethylphenol 0.000648 0.0000787 0.000291 0.0000354 μg/l 

SVOC 2,6,10,14-Tetramethyl Pentadecane 0.00405 0.000492 0.00182 0.000221 μg/l 

SVOC 2,6,10,14-Tetramethylhexadecae 0.00271 0.000329 0.00122 0.000148 μg/l 

SVOC 2,6,10,14-Tetramethylhexadecae (01) 0.0000875 0.0000106 0.0000393 0.00000477 μg/l 

SVOC 2,6-dimethyl-Heptadecane 0.00442 0.000536 0.00199 0.000241 μg/l 

SVOC 2,7-Dimethylnaphthalene 0.00317 0.000385 0.00142 0.000173 μg/l 

SVOC 2-Cyclopenten1-one 0.000304 0.0000369 0.000137 0.0000166 μg/l 

SVOC 2-Ethyl-Hexanoic acid 0.031 0.00376 0.0139 0.00169 μg/l 

SVOC 2-Hydroxy-Benzaldehyde 0.00471 0.000572 0.00212 0.000257 μg/l 

SVOC 2-Mercaptobenzothiazole 0 0 0 0 μg/l 

SVOC 2-Methyl Tridecane 0.0000463 0.00000562 0.0000208 0.00000253 μg/l 

SVOC 2-Methyl-Benzaldehyde 0.00199 0.000241 0.000894 0.000109 μg/l 

SVOC 2-Methyl-Dodecane 0.0000384 0.00000466 0.0000172 0.00000209 μg/l 

SVOC 2-Methylnaphthalene 0.015 0.00182 0.00675 0.000819 μg/l 

SVOC 2-Naphthalenecarboxaldehyde 0.000333 0.0000404 0.00015 0.0000182 μg/l 

SVOC 3,4-Dimethylphenol 0.000000341 4.14E-08 1.53E-07 1.86E-08 μg/l 

SVOC 3,5-Dimethyl-Benzaldehyde 0.000000441 5.35E-08 1.98E-07 2.4E-08 μg/l 

SVOC 3,6-Dimethylundecane 0.000000671 8.15E-08 3.02E-07 3.66E-08 μg/l 

SVOC 3-Methyl-Benzaldehyde 0.00423 0.000513 0.0019 0.000231 μg/l 

SVOC 3-Methyl-Benzaldehyde (01) 0.00474 0.000576 0.00213 0.000259 μg/l 

SVOC 3-Methyl-butanoic acid 0.000147 0.0000178 0.000066 0.00000801 μg/l 

SVOC 3-Methyl-Phenanthrene 0.00198 0.000241 0.000892 0.000108 μg/l 

SVOC 3-Methylphenol 0.000222 0.0000269 0.0000997 0.0000121 μg/l 

SVOC 3-Phenyl-2-Propenal 0.00015 0.0000182 0.0000673 0.00000817 μg/l 

SVOC 4,4-Dimethylbiphenyl 0.00206 0.00025 0.000927 0.000113 μg/l 

SVOC 4-Hydroxy-2-Butanone 0.00231 0.00028 0.00104 0.000126 μg/l 

SVOC 4-Methyl-1H-Benzotriazole 0.00000232 2.82E-07 0.00000104 1.27E-07 μg/l 

SVOC 4-METHYL-PENTANOIC ACID 0.0000978 0.0000119 0.000044 0.00000534 μg/l 

G-34
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.5: Fishing Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

1 and 3 

Model 

Scenarios

2 and 4 

Model 

Scenarios 

5 and 7 

Model 

Scenarios 

6 and 8 

Units 

SVOC 5-Butyl-Hexadecane 0.000000517 6.27E-08 2.32E-07 2.82E-08 μg/l 

SVOC 5-Methyl-2-(1-methyl)-Cyclohexanol 0.00000227 2.76E-07 0.00000102 1.24E-07 μg/l 

SVOC 9-Methyl-9H-Fluorene 0.00212 0.000258 0.000954 0.000116 μg/l 

SVOC Acenaphthylene 0.00115 0.00014 0.000517 0.0000628 μg/l 

SVOC Acetophenone 0.0000146 0.00000177 0.00000655 7.94E-07 μg/l 

SVOC Benzeneacetic Acid 0.0000747 0.00000906 0.0000336 0.00000407 μg/l 

SVOC Benzenepropanoic Acid 0.0000824 0.00001 0.000037 0.00000449 μg/l 

SVOC Benzothiazole 0.0000096 0.00000116 0.00000431 5.24E-07 μg/l 

SVOC Benzyl alcohol 0.0000152 0.00000185 0.00000684 0.00000083 μg/l 

SVOC Biphenyl 0.00116 0.00014 0.000519 0.000063 μg/l 

SVOC Bis(2-ethylhexyl) phthalate 0.000485 0.0000588 0.000218 0.0000264 μg/l 

SVOC Caprolactam 0.0000082 9.95E-07 0.00000368 4.47E-07 μg/l 

SVOC Cholesterol 0.000227 0.0000275 0.000102 0.0000124 μg/l 

SVOC Cyclic octaatomic sulfur 0.0073 0.000886 0.00328 0.000398 μg/l 

SVOC Cyclodecane 0.0000795 0.00000964 0.0000357 0.00000433 μg/l 

SVOC Cyclododecane 0.00000901 0.00000109 0.00000405 4.91E-07 μg/l 

SVOC Cyclotetradecane 0.00000475 5.77E-07 0.00000214 2.59E-07 μg/l 

SVOC Diethene Glycol Monododecyl Ether 0.00000896 0.00000109 0.00000403 4.89E-07 μg/l 

SVOC Dimethyl phthalate 0.0000271 0.00000329 0.0000122 0.00000148 μg/l 

SVOC Di-n-butyl phthalate 0.000596 0.0000723 0.000268 0.0000325 μg/l 

SVOC Di-n-octyl phthalate 0.0000173 0.0000021 0.00000778 9.44E-07 μg/l 

SVOC Disopropylene glycol 0.00000264 3.21E-07 0.00000119 1.44E-07 μg/l 

SVOC Dodecane 0.000000386 4.68E-08 1.73E-07 2.1E-08 μg/l 

SVOC Dodecanoic acid 0.0000065 7.89E-07 0.00000292 3.55E-07 μg/l 

SVOC Eicosane 0.0101 0.00122 0.00453 0.000549 μg/l 

SVOC Ethanol, 2,2-oxybis- 0.000292 0.0000355 0.000131 0.0000159 μg/l 

SVOC Ethanol, 2-Butoxy 0.00258 0.000313 0.00116 0.000141 μg/l 

SVOC Fluorene 0.00123 0.000149 0.000552 0.0000669 μg/l 

SVOC Heneicosane 0.00301 0.000365 0.00135 0.000164 μg/l 

SVOC Heptadecane 0.0179 0.00218 0.00806 0.000979 μg/l 

SVOC Hexaethylene Glycol Monododecyl 0.00000545 6.62E-07 0.00000245 2.97E-07 μg/l 

SVOC Hexaethylene Glycol Monododecyl (01) 0.00000218 2.65E-07 9.82E-07 1.19E-07 μg/l 

SVOC Hexaethylene Glycol Monododecyl (02) 0.00000069 8.37E-08 0.00000031 3.76E-08 μg/l 

SVOC Hexagol 0.00000315 3.82E-07 0.00000141 1.72E-07 μg/l 

SVOC Indane 0.000257 0.0000312 0.000116 0.000014 μg/l 

SVOC Indole 0.000412 0.00005 0.000185 0.0000225 μg/l 

SVOC Isopropylbenzene-4,methyl-1 0 0 0 0 μg/l 

SVOC m-Cresol 0.0000235 0.00000285 0.0000106 0.00000128 μg/l 

SVOC Naphthalene 0.00547 0.000663 0.00246 0.000298 μg/l 

SVOC N-Butyl-Benzenesulfonamide 0.0000009 1.09E-07 4.04E-07 4.91E-08 μg/l 

SVOC n-Hexadecane 0.0171 0.00207 0.00768 0.000932 μg/l 

SVOC n-Hexadecanoic acid 0.0000046 5.58E-07 0.00000207 2.51E-07 μg/l 

SVOC Nonadecane 0.0138 0.00168 0.0062 0.000753 μg/l 

G-35
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

G-36

Appendix G.5: Fishing Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

1 and 3 

Model 

Scenarios

2 and 4 

Model 

Scenarios 

5 and 7 

Model 

Scenarios 

6 and 8 

Units 

SVOC Nonadecane (01) 0.00425 0.000516 0.00191 0.000232 μg/l 

SVOC Nonanoic Acid 0.00335 0.000407 0.00151 0.000183 μg/l 

SVOC n-Pentadecane 0.0127 0.00155 0.00573 0.000695 μg/l 

SVOC n-Tetradecane 0.0161 0.00195 0.00722 0.000876 μg/l 

SVOC o-Cresol 0.0019 0.000231 0.000856 0.000104 μg/l 

SVOC Octadecane 0.00388 0.000471 0.00174 0.000211 μg/l 

SVOC p-Cresol 0.00573 0.000696 0.00258 0.000313 μg/l 

SVOC Pentacosane 0.0000797 0.00000968 0.0000358 0.00000435 μg/l 

SVOC Pentaethene Glycol Monododecyl Ether 0.000000738 8.95E-08 3.31E-07 4.02E-08 μg/l 

SVOC 

Pentaethene Glycol Monododecyl Ether 

(01) 0.00000539 6.54E-07 0.00000242 2.94E-07 μg/l 

SVOC 

Pentaethene Glycol Monododecyl Ether 

(02) 0.0000106 0.00000129 0.00000477 5.79E-07 μg/l 

SVOC Phenanthrene 0.00105 0.000127 0.00047 0.0000571 μg/l 

SVOC Phenol 0.0119 0.00145 0.00537 0.000652 μg/l 

SVOC Phthalic acid, isobutyl octyl ester 0.00000426 5.17E-07 0.00000192 2.32E-07 μg/l 

SVOC Pyrene 0.0000391 0.00000474 0.0000176 0.00000213 μg/l 

SVOC Sulfur 0.00332 0.000403 0.00149 0.000181 μg/l 

SVOC Tetraethylene glycol monododecyl ether 0.00000549 6.67E-07 0.00000247 0.0000003 μg/l 

SVOC Triethyl phosphate 0.0000557 0.00000676 0.000025 0.00000304 μg/l 

SVOC Triethylene glycol monododecyl ether 0.00000816 0.00000099 0.00000367 4.45E-07 μg/l 

SVOC Unknown SVOC 0.00318 0.000386 0.00143 0.000173 μg/l 

SVOC Unknown SVOC (01) 0.00293 0.000355 0.00132 0.00016 μg/l 

SVOC Unknown SVOC (02) 0.00313 0.00038 0.00141 0.000171 μg/l 

SVOC Unknown SVOC (03) 0.000223 0.0000271 0.0001 0.0000122 μg/l 

SVOC Unknown SVOC (04) 0.000209 0.0000253 0.0000938 0.0000114 μg/l 

SVOC Unknown SVOC (05) 0.0000616 0.00000747 0.0000277 0.00000336 μg/l 

SVOC Unknown SVOC (06) 0.0000407 0.00000494 0.0000183 0.00000222 μg/l 

SVOC Unknown SVOC (07) 0.000462 0.0000561 0.000208 0.0000252 μg/l 

(1) EPA suspects a limited number of the samples analyzed for selenium (even fewer for arsenic) for 

bilgewater, packing gland effluent, propulsion engine effluent, graywater and deck washdown water may 

be positively influenced (increased) by interference from high concentrations of major cations in the 

sample matrix. Although EPA suspects that the highest concentrations of dissolved arsenic (and to a lesser 

extent selenium) in fish hold effluent from a shrimping vessel could be slightly elevated due to cation 

interference; EPA believes the fish hold concentrations reasonably represent true effluent concentrations 

for the discharge (see Section 3.2.4.1). EPA considered these interferences when interpreting the potential 

for vessel discharges to pose a risk to human health, aquatic life, or the environment and determined that 

such cationic interference does not influence the major findings presented in the modeling analysis.
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.6: Metropolitan Harbor Vessel Scenarios Instantaneous Concentration 

in the Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

9 and 11 

Model 

Scenarios 

10 an 12 

Model 

Scenarios 

13 and 15 

Model 

Scenarios 

14 and 16 

Units 

Bacteria E. Coli by MF 3.2 0.388 1.44 0.175 

CFU/100 

ml 

Bacteria E. Coli by MPN 1.15 0.14 0.518 0.0629 

MPN/100 

ml 

Bacteria Enterococci by MF 1.81 0.219 0.812 0.0985 

CFU/100 

ml 

Bacteria Enterococci by MPN 0.0643 0.00781 0.0289 0.00351 

MPN/100 

ml 

Bacteria Fecal Coliform by MF 5.89 0.715 2.65 0.321 

CFU/100 

ml 

Bacteria Fecal Coliform by MPN 3.61 0.438 1.62 0.197 

MPN/100 

ml 

Bacteria Total Coliforms by MPN 15.5 1.88 6.96 0.845 

MPN/100 

ml 

Classicals Biochemical Oxygen Demand (BOD) 0.158 0.0191 0.0709 0.0086 mg/l 

Classicals Chemical Oxygen Demand (COD) 0.43 0.0522 0.193 0.0235 mg/l 

Classicals Dissolved Oxygen 0.0122 0.00149 0.0055 0.000668 mg/l 

Classicals Hexane Extractable Material (HEM) 0.00626 0.00076 0.00281 0.000341 mg/l 

Classicals Silica Gel Treated HEM (SGT-HEM) 0.0068 0.000825 0.00305 0.000371 mg/l 

Classicals Sulfide 0.00000934 0.00000113 0.0000042 0.00000051 mg/l 

Classicals Total Organic Carbon (TOC) 0.0606 0.00735 0.0272 0.0033 mg/l 

Classicals Total Residual Chlorine 0.000239 0.000029 0.000108 0.0000131 mg/l 

Classicals Total Suspended Solids (TSS) 0.0678 0.00823 0.0305 0.0037 mg/l 

Nutrients Ammonia As Nitrogen (NH3-N) 0.00199 0.000241 0.000894 0.000109 mg/l 

Nutrients Nitrate/Nitrite (NO3/NO2-N) 0.0000664 0.00000806 0.0000298 0.00000362 mg/l 

Nutrients Total Kjeldahl Nitrogen (TKN) 0.0224 0.00272 0.0101 0.00122 mg/l 

Nutrients Total Phosphorus 0.00292 0.000354 0.00131 0.000159 mg/l 

Metals Aluminum, Dissolved 0.556 0.0675 0.25 0.0304 μg/l 

Metals Aluminum, Total 0.885 0.107 0.398 0.0483 μg/l 

Metals Antimony, Dissolved 0.0000364 0.00000442 0.0000163 0.00000198 μg/l 

Metals Antimony, Total 0.000114 0.0000138 0.0000512 0.00000622 μg/l 

Metals Arsenic, Dissolved 1 0.00933 0.00113 0.00419 0.000509 μg/l 

Metals Arsenic, Total 1 0.0118 0.00143 0.00528 0.000641 μg/l 

Metals Barium, Dissolved 0.0245 0.00297 0.011 0.00133 μg/l 

Metals Barium, Total 0.0293 0.00356 0.0132 0.0016 μg/l 

Metals Cadmium, Dissolved 0.0000142 0.00000172 0.00000637 7.74E-07 μg/l 

Metals Cadmium, Total 0.000215 0.0000261 0.0000968 0.0000118 μg/l 

Metals Calcium, Dissolved 184 22.3 82.7 10 μg/l 

Metals Calcium, Total 185 22.5 83.3 10.1 μg/l 

Metals Chromium, Dissolved 0.00147 0.000178 0.000659 0.00008 μg/l 

Metals Chromium, Total 0.00292 0.000354 0.00131 0.000159 μg/l 

Metals Cobalt, Dissolved 0.0000603 0.00000732 0.0000271 0.00000329 μg/l 

Metals Cobalt, Total 0.0000859 0.0000104 0.0000386 0.00000468 μg/l 

Metals Copper, Dissolved 1.63 0.198 0.733 0.0889 μg/l 

Metals Copper, Total 0.0586 0.00712 0.0264 0.0032 μg/l 

Metals Iron, Dissolved 0.0152 0.00185 0.00685 0.000831 μg/l 

Metals Iron, Total 0.268 0.0326 0.121 0.0146 μg/l 

G-37
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.6: Metropolitan Harbor Vessel Scenarios Instantaneous Concentration 

in the Hypothetical Harbor 

Model Model Model Model 

Class Analyte Scenarios 

9 and 11 

Scenarios 

10 an 12 

Scenarios 

13 and 15 

Scenarios Units 

14 and 16 

Metals Lead, Dissolved 0.00111 0.000134 0.000497 0.0000604 μg/l 

Metals Lead, Total 0.00506 0.000614 0.00227 0.000276 μg/l 

Metals Magnesium, Dissolved 493 59.8 221 26.9 μg/l 

Metals Magnesium, Total 483 58.6 217 26.3 μg/l 

Metals Manganese, Dissolved 0.0755 0.00916 0.0339 0.00412 μg/l 

Metals Manganese, Total 0.097 0.0118 0.0436 0.00529 μg/l 

Metals Nickel, Dissolved 0.00459 0.000557 0.00206 0.00025 μg/l 

Metals Nickel, Total 0.00541 0.000657 0.00243 0.000295 μg/l 

Metals Potassium, Dissolved 34.5 4.19 15.5 1.88 μg/l 

Metals Potassium, Total 34.3 4.17 15.4 1.87 μg/l 

Metals Selenium, Dissolved 1 0.0135 0.00164 0.00606 0.000736 μg/l 

Metals Selenium, Total 1 0.0144 0.00175 0.00648 0.000787 μg/l 

Metals Silver, Dissolved 0.00000723 8.78E-07 0.00000325 3.94E-07 μg/l 

Metals Silver, Total 0.0000136 0.00000165 0.00000611 7.42E-07 μg/l 

Metals Sodium, Dissolved 806 97.8 362 44 μg/l 

Metals Sodium,Total 944 115 424 51.5 μg/l 

Metals Thallium, Dissolved 0.0000233 0.00000282 0.0000105 0.00000127 μg/l 

Metals Thallium,Total 2.57E-07 3.12E-08 1.16E-07 1.4E-08 μg/l 

Metals Vanadium, Dissolved 0.000658 0.0000799 0.000296 0.0000359 μg/l 

Metals Vanadium,Total 0.000882 0.000107 0.000397 0.0000481 μg/l 

Metals Zinc, Dissolved 0.0968 0.0117 0.0435 0.00528 μg/l 

Metals Zinc, Total 0.201 0.0244 0.0903 0.011 μg/l 

Nonylphenols Bisphenol A 0.00000581 7.05E-07 0.00000261 3.17E-07 μg/l 

Nonylphenols Nonylphenol decaethoxylate (NP10EO) 0.00111 0.000134 0.000497 0.0000604 μg/l 

Nonylphenols Nonylphenol dodecaethoxylate (NP12EO) 0.000885 0.000107 0.000398 0.0000483 μg/l 

Nonylphenols 

Nonylphenol heptadecaethoxylate 

(NP17EO) 0.0000557 0.00000675 0.000025 0.00000304 μg/l 

Nonylphenols Nonylphenol heptaethoxylate (NP7EO) 0.000689 0.0000837 0.00031 0.0000376 μg/l 

Nonylphenols 

Nonylphenol hexadecaethoxylate 

(NP16EO) 0.000119 0.0000144 0.0000534 0.00000648 μg/l 

Nonylphenols Nonylphenol hexaethoxylate (NP6EO) 0.00048 0.0000583 0.000216 0.0000262 μg/l 

Nonylphenols Nonylphenol nonaethoxylate (NP9EO) 0.000983 0.000119 0.000442 0.0000536 μg/l 

Nonylphenols Nonylphenol octaethoxylate (NP8EO) 0.000882 0.000107 0.000397 0.0000481 μg/l 

Nonylphenols 

Nonylphenol octodecaethoxylate 

(NP18EO) 0.0000268 0.00000325 0.000012 0.00000146 μg/l 

Nonylphenols 

Nonylphenol pendecaethoxylate 

(NP15EO) 0.000224 0.0000272 0.000101 0.0000122 μg/l 

Nonylphenols Nonylphenol pentaethoxylate (NP5EO) 0.000282 0.0000342 0.000127 0.0000154 μg/l 

Nonylphenols 

Nonylphenol tetradecaethoxylate 

(NP14EO) 0.000406 0.0000493 0.000182 0.0000221 μg/l 

Nonylphenols Nonylphenol tetraethoxylate (NP4EO) 0.000128 0.0000155 0.0000575 0.00000698 μg/l 

Nonylphenols Nonylphenol tridecaethoxylate (NP13EO) 0.000627 0.0000762 0.000282 0.0000342 μg/l 

Nonylphenols Nonylphenol triethoxylate (NP3EO) 0.000074 0.00000898 0.0000332 0.00000403 μg/l 

Nonylphenols Nonylphenol undecaethoxylate (NP11EO) 0.00112 0.000136 0.000505 0.0000613 μg/l 

Nonylphenols Octylphenol decaethoxylate (OP10EO) 0.0000832 0.0000101 0.0000374 0.00000454 μg/l 

Nonylphenols Octylphenol dodecaethoxylate (OP12EO) 0.00004 0.00000485 0.000018 0.00000218 μg/l 

G-38
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.6: Metropolitan Harbor Vessel Scenarios Instantaneous Concentration 

in the Hypothetical Harbor 

Model Model Model Model 

Class Analyte Scenarios 

9 and 11 

Scenarios 

10 an 12 

Scenarios 

13 and 15 

Scenarios Units 

14 and 16 

Nonylphenols Octylphenol heptaethoxylate (OP7EO) 0.00000494 0.0000006 0.00000222 0.00000027 μg/l 

Nonylphenols Octylphenol nonaethoxylate (OP9EO) 0.0000265 0.00000321 0.0000119 0.00000144 μg/l 

Nonylphenols Octylphenol octaethoxylate (OP8EO) 0.0000422 0.00000512 0.000019 0.0000023 μg/l 

Nonylphenols Octylphenol undecaethoxylate (OP11EO) 0.0000494 0.000006 0.0000222 0.0000027 μg/l 

Nonylphenols Total Nonylphenol Polyethoxylates 0.0076 0.000923 0.00342 0.000415 μg/l 

Nonylphenols Total Nonylphenols 0.00004 0.00000486 0.000018 0.00000218 μg/l 

VOC (2-Methyl-1-Propenyl)-Benzene 0.00195 0.000237 0.000877 0.000106 μg/l 

VOC (E)-1-Propenyl-Benzene 0.00000221 2.68E-07 9.94E-07 1.21E-07 μg/l 

VOC (E)-2-Butenal 0.00357 0.000433 0.0016 0.000195 μg/l 

VOC 1,2,3,4-Tetrahydro-1-Methylnaphthalene 0.00224 0.000272 0.00101 0.000122 μg/l 

VOC 1,2,3,4-Tetrahydro-2-Methylnaphthalene 0.00207 0.000251 0.00093 0.000113 μg/l 

VOC 1,2,3,4-Tetrahydro-5-Methylnaphthalene 0.0182 0.00221 0.00819 0.000994 μg/l 

VOC 1,2,3,4-Tetrahydro-6-Ethylnaphthalene, 0.00195 0.000237 0.000879 0.000107 μg/l 

VOC 1,2,3,4-Tetrahydro-6-Methylnaphthalene 0.0168 0.00204 0.00754 0.000915 μg/l 

VOC 

1,2,3,4-Tetrahydro-6-Methylnaphthalene 

(01) 0.00415 0.000504 0.00187 0.000226 μg/l 

VOC 

1,2,3,4-Tetrahydro-6-Methylnaphthalene 

(02) 0.00347 0.000422 0.00156 0.000189 μg/l 

VOC 1,2,3,4-Tetrahydronaphthalene 0.0125 0.00152 0.00562 0.000682 μg/l 

VOC 1,2,3,4-Tetramethyl-Benzene 0.0014 0.000171 0.000631 0.0000766 μg/l 

VOC 1,2,3,5-Tetramethyl-Benzene 0.00207 0.000251 0.000929 0.000113 μg/l 

VOC 1,2,3-Trimethylbenzene 0.00675 0.000819 0.00303 0.000368 μg/l 

VOC 1,2,4,5-Tetramethylbenzene 0.00315 0.000383 0.00142 0.000172 μg/l 

VOC 1,2,4-Trimethylbenzene 0.0092 0.00112 0.00413 0.000502 μg/l 

VOC 1,3,5-Trimethylbenzene 0.00268 0.000326 0.00121 0.000146 μg/l 

VOC 1,3-Methylnaphthalene 0.00256 0.000311 0.00115 0.00014 μg/l 

VOC 1,7-Methylnaphthalene 0.0116 0.00141 0.00521 0.000632 μg/l 

VOC 1-Ethyl-2,3-Dimethyl-Benzene (01) 0.00313 0.00038 0.00141 0.000171 μg/l 

VOC 1-Ethyl-2,3-Dimethyl-Benzene (02) 0.000859 0.000104 0.000386 0.0000469 μg/l 

VOC 1-Ethyl-2,4-Dimethyl-Benzene 0.00334 0.000405 0.0015 0.000182 μg/l 

VOC 1-Ethyl-2-Methyl-Benzene 0.00000683 8.29E-07 0.00000307 3.72E-07 μg/l 

VOC 1-Ethyl-3-Methyl-Benzene 0.00217 0.000264 0.000977 0.000119 μg/l 

VOC 1-Ethyl-4-Methyl-Benzene 0.0141 0.00171 0.00632 0.000768 μg/l 

VOC 1-Methyl-2-(1-Methylethyl)-Benzene 0 0 0 0 μg/l 

VOC 1-Methyl-2-(1-Methylethyl)-Benzene (01) 0.00000553 6.71E-07 0.00000248 3.01E-07 μg/l 

VOC 1-Methyl-2-(1-Methylethyl)-Benzene (02) 0.0000193 0.00000234 0.00000868 0.00000105 μg/l 

VOC 1-Methyl-3-Propyl-Benzene 0.00274 0.000333 0.00123 0.000149 μg/l 

VOC 1-Methyl-4-(1-Methylidene)-Cyclohexane 0 0 0 0 μg/l 

VOC 1-methyl-Indan 0.00657 0.000798 0.00296 0.000359 μg/l 

VOC 1-Propenyl-Benzene 0.00000254 3.08E-07 0.00000114 1.38E-07 μg/l 

VOC 2- Heptanone 0.000131 0.0000159 0.000059 0.00000716 μg/l 

VOC 2,3-Dihydro-1,2-Dimethyl-1H-Indene 0.000706 0.0000858 0.000318 0.0000385 μg/l 

VOC 2,3-Dihydro-1,6-Dimethyl-1H-Indene 0.00338 0.00041 0.00152 0.000184 μg/l 

VOC 2,3-Dihydro-1-Methylindene 0.0034 0.000413 0.00153 0.000186 μg/l 

G-39
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.6: Metropolitan Harbor Vessel Scenarios Instantaneous Concentration 

in the Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

9 and 11 

Model 

Scenarios 

13 and 15 

Model 

Scenarios 

14 and 16 

Units 

Model 

Scenarios 

10 an 12 

VOC 2,3-Dihydro-1-methylindene (01) 0.0019 0.00023 0.000853 0.000104 μg/l 

VOC 2,3-Dihydro-1-methylindene (02) 0.00402 0.000489 0.00181 0.00022 μg/l 

VOC 2,3-Dihydro-4,7-Dimethyl-1H-Indene 0.000067 0.00000813 0.0000301 0.00000365 μg/l 

VOC 2,3-Dihydro-4-Methyl-1H-Indene 0.0391 0.00475 0.0176 0.00213 μg/l 

VOC 2,3-Dihydro-4-Methyl-1H-Indene (01) 0.00000787 9.55E-07 0.00000354 4.29E-07 μg/l 

VOC 2,3-Dihydro-4-Methyl-1H-Indene (02) 0.0000133 0.00000161 0.00000596 7.24E-07 μg/l 

VOC 2,3-Dihydro-5,6-dimethyl-1H-Indene 0.00184 0.000223 0.000827 0.0001 μg/l 

VOC 2,3-Dihydro-5-methyl-1H-Indene 0.00347 0.000422 0.00156 0.000189 μg/l 

VOC 2,6-Dimethylnaphthalene 0.0252 0.00306 0.0113 0.00137 μg/l 

VOC 2-Butanone 0.0201 0.00244 0.00903 0.0011 μg/l 

VOC 2-Butenal 0.00223 0.00027 0.001 0.000121 μg/l 

VOC 2-Ethyl-1,3,5-Trimethyl-Benzene 0.00268 0.000326 0.00121 0.000146 μg/l 

VOC 2-Ethyl-1,4-Dimethyl-Benzene 0.0124 0.00151 0.00557 0.000677 μg/l 

VOC 2-Ethyl-1-Hexanol 0.00000243 2.95E-07 0.00000109 1.32E-07 μg/l 

VOC 2-Ethyltoluene 0.00686 0.000832 0.00308 0.000374 μg/l 

VOC 2-Hexanone 0.00184 0.000223 0.000827 0.0001 μg/l 

VOC 2-Methyl-2-Propenal 0.00427 0.000519 0.00192 0.000233 μg/l 

VOC 2-Propenyl-Benzene 0.0103 0.00125 0.00462 0.000561 μg/l 

VOC 3-Buten-2-one 0.00384 0.000466 0.00173 0.00021 μg/l 

VOC 4-Ethyl-1,2-Dimethyl-Benzene 0.00000702 8.52E-07 0.00000316 3.83E-07 μg/l 

VOC 4-Heptanone 0.000174 0.0000211 0.000078 0.00000947 μg/l 

VOC 4-Isopropyltoluene 0.000612 0.0000743 0.000275 0.0000334 μg/l 

VOC 4-Methyl-2-Pentanone 0.000597 0.0000725 0.000268 0.0000326 μg/l 

VOC Acetaldehyde 0.0122 0.00148 0.00546 0.000663 μg/l 

VOC Acetone 0.0889 0.0108 0.04 0.00485 μg/l 

VOC Acrolein 0.00508 0.000617 0.00228 0.000277 μg/l 

VOC Benzaldehyde 0.000155 0.0000189 0.0000698 0.00000847 μg/l 

VOC Benzene 0.00681 0.000826 0.00306 0.000371 μg/l 

VOC Benzocycloheptatriene 0.0238 0.00289 0.0107 0.0013 μg/l 

VOC Benzofuran 0.00241 0.000293 0.00108 0.000132 μg/l 

VOC Bromodichloromethane 0.00000908 0.0000011 0.00000408 4.96E-07 μg/l 

VOC Butane 0.00114 0.000138 0.000512 0.0000621 μg/l 

VOC Butyraldehyde 0.003 0.000365 0.00135 0.000164 μg/l 

VOC Carbon disulfide 0.00000183 2.22E-07 8.23E-07 9.99E-08 μg/l 

VOC Chloroform 0.0016 0.000194 0.000718 0.0000872 μg/l 

VOC cis-1,2-Dichloroethene 0.00000282 3.42E-07 0.00000127 1.54E-07 μg/l 

VOC Cyclohexane 0.000144 0.0000175 0.0000646 0.00000785 μg/l 

VOC Dibromochloromethane 0.00000891 0.00000108 0.00000401 4.86E-07 μg/l 

VOC Dimethocxymethane 0.00427 0.000518 0.00192 0.000233 μg/l 

VOC Ethanol 0.0000464 0.00000563 0.0000209 0.00000253 μg/l 

VOC Ethylbenzene 0.00375 0.000455 0.00168 0.000204 μg/l 

VOC Indene 0.00012 0.0000146 0.0000541 0.00000657 μg/l 

VOC Isopropylbenzene 0.00106 0.000129 0.000476 0.0000578 μg/l 

G-40
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.6: Metropolitan Harbor Vessel Scenarios Instantaneous Concentration 

in the Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

9 and 11 

Model 

Scenarios 

10 an 12 

Model 

Scenarios 

13 and 15 

Model 

Scenarios 

14 and 16 

Units 

VOC Limonene 0 0 0 0 μg/l 

VOC m,p-Xylene (Sum of Isomers) 0.0136 0.00165 0.0061 0.00074 μg/l 

VOC Methyl acetate 0.00125 0.000152 0.000562 0.0000682 μg/l 

VOC Methyl tertiary butyl ether (MTBE) 0.0000185 0.00000224 0.00000831 0.00000101 μg/l 

VOC Methylcyclohexane 0.000131 0.0000158 0.0000587 0.00000712 μg/l 

VOC Methylene chloride 0.00034 0.0000413 0.000153 0.0000185 μg/l 

VOC n-Butylbenzene 0.000537 0.0000651 0.000241 0.0000293 μg/l 

VOC nitro-Methane 0.00178 0.000216 0.000801 0.0000972 μg/l 

VOC Nonanal 0.0000012 1.46E-07 5.39E-07 6.55E-08 μg/l 

VOC n-Propylbenzene 0.00103 0.000125 0.000461 0.000056 μg/l 

VOC n-Valeraldehyde 0.00268 0.000326 0.00121 0.000146 μg/l 

VOC O-Xylene 0.00876 0.00106 0.00394 0.000478 μg/l 

VOC sec-Butylbenzene 0.00122 0.000148 0.000548 0.0000666 μg/l 

VOC Styrene 0.00121 0.000146 0.000542 0.0000658 μg/l 

VOC Sulfur dioxide 0.0126 0.00153 0.00568 0.000689 μg/l 

VOC Tetrachloroethene 0.00000259 3.14E-07 0.00000116 1.41E-07 μg/l 

VOC Toluene 0.0137 0.00166 0.00614 0.000746 μg/l 

VOC Trichloroethene 0.00000197 2.39E-07 8.86E-07 1.08E-07 μg/l 

VOC Trichlorofluoromethane 0.00104 0.000126 0.000465 0.0000565 μg/l 

VOC Tridecane 0.00213 0.000258 0.000956 0.000116 μg/l 

VOC Unknown VOC 0.00297 0.000361 0.00134 0.000162 μg/l 

VOC Unknown VOC (01) 0.00196 0.000237 0.000879 0.000107 μg/l 

VOC Unknown VOC (02) 0.00255 0.000309 0.00114 0.000139 μg/l 

VOC Unknown VOC (03) 0.00232 0.000281 0.00104 0.000126 μg/l 

VOC Unknown VOC (04) 0.00158 0.000192 0.000711 0.0000863 μg/l 

VOC Unknown VOC (05) 0.00142 0.000173 0.000639 0.0000775 μg/l 

VOC Vinyl acetate 0.00133 0.000162 0.000599 0.0000727 μg/l 

SVOC (E)-2-Tetradecene 0.000388 0.0000471 0.000174 0.0000212 μg/l 

SVOC 

1,2,3,4-Tetrahydro-2,7-

Dimethylnaphthalene 0.000368 0.0000447 0.000166 0.0000201 μg/l 

SVOC 1,2,3-Trichloro-(Z)-1-Propene 0.000108 0.0000131 0.0000485 0.00000589 μg/l 

SVOC 1,2,3-Trimethylbenzene (1) 0.00157 0.00019 0.000705 0.0000856 μg/l 

SVOC 1,2,3-Trimethylbenzene (2) 0.002 0.000243 0.0009 0.000109 μg/l 

SVOC 1,2,4,5-Tetramethylbenzene (1) 0.00022 0.0000267 0.0000989 0.000012 μg/l 

SVOC 1,2,4,5-Tetramethylbenzene (2) 0.000204 0.0000248 0.0000917 0.0000111 μg/l 

SVOC 1,2-Diethyl-Cyclobutane 0.0061 0.00074 0.00274 0.000333 μg/l 

SVOC 1,3-Dimethylnaphthalene 0.000135 0.0000163 0.0000605 0.00000734 μg/l 

SVOC 1,3-Dimethylnaphthalene (01) 0.00346 0.000419 0.00155 0.000189 μg/l 

SVOC 

1,4-Dimethyl-1,2,3,4-

tetrahydronaphthalene 0.00511 0.00062 0.0023 0.000279 μg/l 

SVOC 1,4-Dimethylnaphthalene 0.00606 0.000735 0.00272 0.00033 μg/l 

SVOC 1,4-Dimethylnaphthalene (01) 0.00366 0.000445 0.00165 0.0002 μg/l 

SVOC 1,5-Dimethylnaphthalene 0.00151 0.000183 0.000678 0.0000823 μg/l 

SVOC 1,6-Dimethylnaphthalene 0.026 0.00315 0.0117 0.00142 μg/l 

G-41
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.6: Metropolitan Harbor Vessel Scenarios Instantaneous Concentration 

in the Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

9 and 11 

Model 

Scenarios 

10 an 12 

Model 

Scenarios 

13 and 15 

Model 

Scenarios 

14 and 16 

Units 

SVOC 1,7,7-tri-(methyl)-bicyclo[2.2.1]heptane 0 0 0 0 μg/l 

SVOC 1-Dodecanol 0.0000579 0.00000703 0.000026 0.00000316 μg/l 

SVOC 1-Hexadecene 0.00000537 6.52E-07 0.00000241 2.93E-07 μg/l 

SVOC 1-Methyl-2-Propyl-Benzene (01) 0.00166 0.000201 0.000745 0.0000904 μg/l 

SVOC 1-Methyl-2-Propyl-Benzene (02) 0.000478 0.0000581 0.000215 0.0000261 μg/l 

SVOC 1-Methylnaphthalene 0.0242 0.00293 0.0109 0.00132 μg/l 

SVOC 1-Phenyl-1-Butene 0.00000195 2.37E-07 8.77E-07 1.06E-07 μg/l 

SVOC 2-(dodecyloxy)-Ethanol 0.0000724 0.00000879 0.0000325 0.00000395 μg/l 

SVOC 2-(hexadecyloxy)-Ethanol 0.0000186 0.00000226 0.00000835 0.00000101 μg/l 

SVOC 2-(tetradecyloxy)-Ethanol 0.0000536 0.00000651 0.0000241 0.00000293 μg/l 

SVOC 2,3-Dimethylnaphthalene 0.00451 0.000547 0.00203 0.000246 μg/l 

SVOC 2,4,6-Trichlorophenol 0.00000929 0.00000113 0.00000418 5.07E-07 μg/l 

SVOC 2,4-Dimethyl-Benzaldehyde 0.00000363 0.00000044 0.00000163 1.98E-07 μg/l 

SVOC 2,4-Dimethylphenol 0.00133 0.000161 0.000597 0.0000724 μg/l 

SVOC 2,6,10,14-Tetramethyl Pentadecane 0.00827 0.001 0.00372 0.000451 μg/l 

SVOC 2,6,10,14-Tetramethylhexadecae 0.00542 0.000657 0.00243 0.000295 μg/l 

SVOC 2,6,10,14-Tetramethylhexadecae (01) 0.000583 0.0000708 0.000262 0.0000318 μg/l 

SVOC 2,6-dimethyl-Heptadecane 0.00884 0.00107 0.00397 0.000482 μg/l 

SVOC 2,7-Dimethylnaphthalene 0.00675 0.000819 0.00303 0.000368 μg/l 

SVOC 2-Cyclopenten1-one 0.000609 0.0000739 0.000274 0.0000332 μg/l 

SVOC 2-Ethyl-Hexanoic acid 0.207 0.0251 0.0929 0.0113 μg/l 

SVOC 2-Hydroxy-Benzaldehyde 0.00957 0.00116 0.0043 0.000522 μg/l 

SVOC 2-Mercaptobenzothiazole 0 0 0 0 μg/l 

SVOC 2-Methyl Tridecane 0.000309 0.0000375 0.000139 0.0000168 μg/l 

SVOC 2-Methyl-Benzaldehyde 0.00399 0.000484 0.00179 0.000218 μg/l 

SVOC 2-Methyl-Dodecane 0.000192 0.0000233 0.0000862 0.0000105 μg/l 

SVOC 2-Methylnaphthalene 0.0313 0.0038 0.0141 0.00171 μg/l 

SVOC 2-Naphthalenecarboxaldehyde 0.000666 0.0000808 0.000299 0.0000363 μg/l 

SVOC 3,4-Dimethylphenol 0.0000017 2.07E-07 7.66E-07 9.29E-08 μg/l 

SVOC 3,5-Dimethyl-Benzaldehyde 0.0000022 2.68E-07 9.91E-07 0.00000012 μg/l 

SVOC 3,6-Dimethylundecane 0.00000336 4.07E-07 0.00000151 1.83E-07 μg/l 

SVOC 3-Methyl-Benzaldehyde 0.00846 0.00103 0.0038 0.000462 μg/l 

SVOC 3-Methyl-Benzaldehyde (01) 0.00949 0.00115 0.00426 0.000518 μg/l 

SVOC 3-Methyl-butanoic acid 0.0000978 0.0000119 0.000044 0.00000534 μg/l 

SVOC 3-Methyl-Phenanthrene 0.00397 0.000482 0.00178 0.000216 μg/l 

SVOC 3-Methylphenol 0.000444 0.0000539 0.000199 0.0000242 μg/l 

SVOC 3-Phenyl-2-Propenal 0.0003 0.0000364 0.000135 0.0000163 μg/l 

SVOC 4,4-Dimethylbiphenyl 0.00412 0.000501 0.00185 0.000225 μg/l 

SVOC 4-Hydroxy-2-Butanone 0.00462 0.00056 0.00208 0.000252 μg/l 

SVOC 4-Methyl-1H-Benzotriazole 0.00000465 5.64E-07 0.00000209 2.54E-07 μg/l 

SVOC 4-METHYL-PENTANOIC ACID 0.0000652 0.00000792 0.0000293 0.00000356 μg/l 

SVOC 5-Butyl-Hexadecane 0.00000258 3.14E-07 0.00000116 1.41E-07 μg/l 

SVOC 5-Methyl-2-(1-methyl)-Cyclohexanol 0.0000152 0.00000184 0.00000681 8.27E-07 μg/l 

G-42
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.6: Metropolitan Harbor Vessel Scenarios Instantaneous Concentration 

in the Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

9 and 11 

Model 

Scenarios 

10 an 12 

Model 

Scenarios 

13 and 15 

Model 

Scenarios 

14 and 16 

Units 

SVOC 9-Methyl-9H-Fluorene 0.00424 0.000515 0.00191 0.000231 μg/l 

SVOC Acenaphthylene 0.00232 0.000281 0.00104 0.000126 μg/l 

SVOC Acetophenone 0.0000728 0.00000884 0.0000327 0.00000397 μg/l 

SVOC Benzeneacetic Acid 0.0000498 0.00000604 0.0000224 0.00000272 μg/l 

SVOC Benzenepropanoic Acid 0.0000549 0.00000667 0.0000247 0.000003 μg/l 

SVOC Benzothiazole 0.0000233 0.00000283 0.0000105 0.00000127 μg/l 

SVOC Benzyl alcohol 0.0000761 0.00000923 0.0000342 0.00000415 μg/l 

SVOC Biphenyl 0.00251 0.000305 0.00113 0.000137 μg/l 

SVOC Bis(2-ethylhexyl) phthalate 0.00119 0.000144 0.000534 0.0000648 μg/l 

SVOC Caprolactam 0.0000546 0.00000663 0.0000246 0.00000298 μg/l 

SVOC Cholesterol 0.000151 0.0000183 0.0000679 0.00000824 μg/l 

SVOC Cyclic octaatomic sulfur 0.0399 0.00484 0.0179 0.00217 μg/l 

SVOC Cyclodecane 0.000397 0.0000482 0.000179 0.0000217 μg/l 

SVOC Cyclododecane 0.0000598 0.00000725 0.0000269 0.00000326 μg/l 

SVOC Cyclotetradecane 0.0000317 0.00000385 0.0000142 0.00000173 μg/l 

SVOC Diethene Glycol Monododecyl Ether 0.0000597 0.00000725 0.0000268 0.00000326 μg/l 

SVOC Dimethyl phthalate 0.0000542 0.00000658 0.0000244 0.00000296 μg/l 

SVOC Di-n-butyl phthalate 0.00134 0.000163 0.000603 0.0000732 μg/l 

SVOC Di-n-octyl phthalate 0.000113 0.0000137 0.0000506 0.00000614 μg/l 

SVOC Disopropylene glycol 0.0000176 0.00000214 0.00000792 9.61E-07 μg/l 

SVOC Dodecane 0.00000193 2.34E-07 8.67E-07 1.05E-07 μg/l 

SVOC Dodecanoic acid 0.0000433 0.00000526 0.0000195 0.00000236 μg/l 

SVOC Eicosane 0.0209 0.00254 0.0094 0.00114 μg/l 

SVOC Ethanol, 2,2-oxybis- 0.00195 0.000236 0.000876 0.000106 μg/l 

SVOC Ethanol, 2-Butoxy 0.00516 0.000626 0.00232 0.000282 μg/l 

SVOC Fluorene 0.00247 0.0003 0.00111 0.000135 μg/l 

SVOC Heneicosane 0.00712 0.000864 0.0032 0.000388 μg/l 

SVOC Heptadecane 0.0362 0.0044 0.0163 0.00198 μg/l 

SVOC Hexaethylene Glycol Monododecyl 0.0000363 0.00000441 0.0000163 0.00000198 μg/l 

SVOC Hexaethylene Glycol Monododecyl (01) 0.0000146 0.00000177 0.00000655 7.94E-07 μg/l 

SVOC Hexaethylene Glycol Monododecyl (02) 0.0000046 5.58E-07 0.00000207 2.51E-07 μg/l 

SVOC Hexagol 0.000021 0.00000255 0.00000943 0.00000114 μg/l 

SVOC Indane 0.00171 0.000208 0.00077 0.0000935 μg/l 

SVOC Indole 0.000275 0.0000333 0.000123 0.000015 μg/l 

SVOC Isopropylbenzene-4,methyl-1 0 0 0 0 μg/l 

SVOC m-Cresol 0.000117 0.0000143 0.0000528 0.00000641 μg/l 

SVOC Naphthalene 0.0129 0.00157 0.00581 0.000706 μg/l 

SVOC N-Butyl-Benzenesulfonamide 0.000006 7.28E-07 0.0000027 3.27E-07 μg/l 

SVOC n-Hexadecane 0.0346 0.0042 0.0155 0.00189 μg/l 

SVOC n-Hexadecanoic acid 0.0000307 0.00000372 0.0000138 0.00000167 μg/l 

SVOC Nonadecane 0.0278 0.00338 0.0125 0.00152 μg/l 

SVOC Nonadecane (01) 0.00851 0.00103 0.00382 0.000464 μg/l 

SVOC Nonanoic Acid 0.00671 0.000814 0.00301 0.000366 μg/l 

G-43
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

G-44

Appendix G.6: Metropolitan Harbor Vessel Scenarios Instantaneous Concentration 

in the Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

9 and 11 

Model 

Scenarios 

10 an 12 

Model 

Scenarios 

13 and 15 

Model 

Scenarios 

14 and 16 

Units 

SVOC n-Pentadecane 0.0312 0.00379 0.014 0.0017 μg/l 

SVOC n-Tetradecane 0.0357 0.00433 0.016 0.00195 μg/l 

SVOC o-Cresol 0.00381 0.000462 0.00171 0.000208 μg/l 

SVOC Octadecane 0.00775 0.000941 0.00348 0.000423 μg/l 

SVOC p-Cresol 0.012 0.00145 0.00537 0.000652 μg/l 

SVOC Pentacosane 0.000532 0.0000645 0.000239 0.000029 μg/l 

SVOC Pentaethene Glycol Monododecyl Ether 0.00000492 5.97E-07 0.00000221 2.68E-07 μg/l 

SVOC 

Pentaethene Glycol Monododecyl Ether 

(01) 0.0000359 0.00000436 0.0000161 0.00000196 μg/l 

SVOC 

Pentaethene Glycol Monododecyl Ether 

(02) 0.0000707 0.00000859 0.0000318 0.00000386 μg/l 

SVOC Phenanthrene 0.00259 0.000314 0.00116 0.000141 μg/l 

SVOC Phenol 0.0241 0.00293 0.0109 0.00132 μg/l 

SVOC Phthalic acid, isobutyl octyl ester 0.00000852 0.00000103 0.00000383 4.65E-07 μg/l 

SVOC Pyrene 0.000257 0.0000311 0.000115 0.000014 μg/l 

SVOC Sulfur 0.0167 0.00203 0.00751 0.000911 μg/l 

SVOC Tetraethylene glycol monododecyl ether 0.0000366 0.00000444 0.0000165 0.000002 μg/l 

SVOC Triethyl phosphate 0.0000427 0.00000518 0.0000192 0.00000233 μg/l 

SVOC Triethylene glycol monododecyl ether 0.0000544 0.0000066 0.0000244 0.00000297 μg/l 

SVOC Unknown SVOC 0.00695 0.000844 0.00312 0.000379 μg/l 

SVOC Unknown SVOC (01) 0.00672 0.000816 0.00302 0.000367 μg/l 

SVOC Unknown SVOC (02) 0.00727 0.000883 0.00327 0.000397 μg/l 

SVOC Unknown SVOC (03) 0.00107 0.00013 0.000481 0.0000584 μg/l 

SVOC Unknown SVOC (04) 0.00111 0.000134 0.000497 0.0000603 μg/l 

SVOC Unknown SVOC (05) 0.000383 0.0000465 0.000172 0.0000209 μg/l 

SVOC Unknown SVOC (06) 0.000248 0.0000301 0.000112 0.0000135 μg/l 

SVOC Unknown SVOC (07) 0.00308 0.000374 0.00138 0.000168 μg/l 

(1) EPA suspects a limited number of the samples analyzed for selenium (even fewer for arsenic) for 

bilgewater, packing gland effluent, propulsion engine effluent, graywater and deck washdown water may 

be positively influenced (increased) by interference from high concentrations of major cations in the 

sample matrix. Although EPA suspects that the highest concentrations of dissolved arsenic (and to a lesser 

extent selenium) in fish hold effluent from a shrimping vessel could be slightly elevated due to cation 

interference; EPA believes the fish hold concentrations reasonably represent true effluent concentrations 

for the discharge (see Section 3.2.4.1). EPA considered these interferences when interpreting the potential 

for vessel discharges to pose a risk to human health, aquatic life, or the environment and determined that 

such cationic interference does not influence the major findings presented in the modeling analysis.
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.7: Recreational Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

17 and 19 

Model 

Scenarios 

18 and 20 

Model 

Scenarios 

21 and 23 

Model 

Scenarios 

22 and 24 

Units 

Bacteria E. Coli by MF 0.533 0.0647 0.24 0.0291 CFU/100 ml 

Bacteria E. Coli by MPN 0.208 0.0252 0.0935 0.0113 

MPN/100 

ml 

Bacteria Enterococci by MF 0.301 0.0365 0.135 0.0164 CFU/100 ml 

Bacteria Enterococci by MPN 0.0395 0.0048 0.0178 0.00216 

MPN/100 

ml 

Bacteria Fecal Coliform by MF 1.47 0.178 0.659 0.0799 CFU/100 ml 

Bacteria Fecal Coliform by MPN 0.602 0.0731 0.271 0.0328 

MPN/100 

ml 

Bacteria Total Coliforms by MPN 2.59 0.314 1.16 0.141 

MPN/100 

ml 

Classicals Biochemical Oxygen Demand (BOD) 0.129 0.0156 0.0578 0.00701 mg/l 

Classicals Chemical Oxygen Demand (COD) 0.361 0.0438 0.162 0.0197 mg/l 

Classicals Dissolved Oxygen 0.0135 0.00164 0.00609 0.000739 mg/l 

Classicals Hexane Extractable Material (HEM) 0.00573 0.000695 0.00257 0.000312 mg/l 

Classicals Silica Gel Treated HEM (SGT-HEM) 0.00682 0.000828 0.00307 0.000372 mg/l 

Classicals Sulfide 6.67E-06 8.09E-07 0.000003 3.64E-07 mg/l 

Classicals Total Organic Carbon (TOC) 0.0483 0.00586 0.0217 0.00263 mg/l 

Classicals Total Residual Chlorine 0.000185 0.0000225 0.0000832 0.0000101 mg/l 

Classicals Total Suspended Solids (TSS) 0.061 0.00741 0.0274 0.00333 mg/l 

Nutrients Ammonia As Nitrogen (NH3-N) 0.00166 0.000202 0.000747 0.0000907 mg/l 

Nutrients Nitrate/Nitrite (NO3/NO2-N) 0.0000333 4.04E-06 0.000015 1.82E-06 mg/l 

Nutrients Total Kjeldahl Nitrogen (TKN) 0.0193 0.00235 0.00868 0.00105 mg/l 

Nutrients Total Phosphorus 0.00254 0.000308 0.00114 0.000138 mg/l 

Metals Aluminum, Dissolved 0.539 0.0654 0.242 0.0294 μg/l 

Metals Aluminum, Total 0.852 0.103 0.383 0.0465 μg/l 

Metals Antimony, Dissolved 0.0000154 1.87E-06 6.92E-06 8.41E-07 μg/l 

Metals Antimony, Total 0.0000448 5.44E-06 0.0000201 2.44E-06 μg/l 

Metals Arsenic, Dissolved 1 0.0084 0.00102 0.00378 0.000458 μg/l 

Metals Arsenic, Total 1 0.0103 0.00125 0.00465 0.000564 μg/l 

Metals Barium, Dissolved 0.0218 0.00265 0.00981 0.00119 μg/l 

Metals Barium, Total 0.0232 0.00282 0.0104 0.00127 μg/l 

Metals Cadmium, Dissolved 0.00001 1.22E-06 4.51E-06 5.47E-07 μg/l 

Metals Cadmium, Total 0.000181 0.0000219 0.0000812 9.85E-06 μg/l 

Metals Calcium, Dissolved 173 21 77.7 9.43 μg/l 

Metals Calcium, Total 175 21.3 78.7 9.55 μg/l 

Metals Chromium, Dissolved 0.00139 0.000169 0.000625 0.0000758 μg/l 

Metals Chromium, Total 0.00234 0.000284 0.00105 0.000128 μg/l 

Metals Cobalt, Dissolved 0.0000254 3.09E-06 0.0000114 1.39E-06 μg/l 

Metals Cobalt, Total 0.0000352 4.28E-06 0.0000158 1.92E-06 μg/l 

Metals Copper, Dissolved 0.902 0.109 0.405 0.0492 μg/l 

Metals Copper, Total 0.0542 0.00658 0.0244 0.00296 μg/l 

Metals Iron, Dissolved 0.00474 0.000576 0.00213 0.000259 μg/l 

Metals Iron, Total 0.197 0.0239 0.0884 0.0107 μg/l 

Metals Lead, Dissolved 0.00112 0.000135 0.000501 0.0000608 μg/l 

Metals Lead, Total 0.00465 0.000564 0.00209 0.000253 μg/l 

Metals Magnesium, Dissolved 456 55.3 205 24.8 μg/l 

Metals Magnesium, Total 447 54.3 201 24.4 μg/l 

Metals Manganese, Dissolved 0.0835 0.0101 0.0375 0.00456 μg/l 

Metals Manganese, Total 0.105 0.0128 0.0473 0.00574 μg/l 

Metals Nickel, Dissolved 0.00437 0.000531 0.00197 0.000239 μg/l 

G-45
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.7: Recreational Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Model Model Model Model 

Class Analyte Scenarios 

17 and 19 

Scenarios 

18 and 20 

Scenarios 

21 and 23 

Scenarios Units 

22 and 24 

Metals Nickel, Total 0.00475 0.000577 0.00214 0.000259 μg/l 

Metals Potassium, Dissolved 37 4.49 16.6 2.02 μg/l 

Metals Potassium, Total 36.9 4.47 16.6 2.01 μg/l 

Metals Selenium, Dissolved 1 0.0145 0.00176 0.00652 0.000792 μg/l 

Metals Selenium, Total 1 0.0154 0.00187 0.00694 0.000842 μg/l 

Metals Silver, Dissolved 4.52E-06 5.49E-07 2.03E-06 2.47E-07 μg/l 

Metals Silver, Total 0.0000085 1.03E-06 3.82E-06 4.64E-07 μg/l 

Metals Sodium, Dissolved 902 110 406 49.2 μg/l 

Metals Sodium,Total 1070 130 480 58.3 μg/l 

Metals Thallium, Dissolved 3.93E-06 4.78E-07 1.77E-06 2.15E-07 μg/l 

Metals Thallium,Total 4.29E-08 5.2E-09 1.93E-08 2.34E-09 μg/l 

Metals Vanadium, Dissolved 0.000742 0.0000901 0.000334 0.0000405 μg/l 

Metals Vanadium,Total 0.000833 0.000101 0.000375 0.0000455 μg/l 

Metals Zinc, Dissolved 0.085 0.0103 0.0382 0.00464 μg/l 

Metals Zinc, Total 0.169 0.0205 0.0759 0.00922 μg/l 

Nonylphenols Bisphenol A 6.97E-06 8.46E-07 3.13E-06 3.8E-07 μg/l 

Nonylphenols Nonylphenol decaethoxylate (NP10EO) 0.00103 0.000125 0.000462 0.0000561 μg/l 

Nonylphenols Nonylphenol dodecaethoxylate (NP12EO) 0.000837 0.000102 0.000376 0.0000456 μg/l 

Nonylphenols Nonylphenol heptadecaethoxylate (NP17EO) 0.0000548 6.65E-06 0.0000246 2.99E-06 μg/l 

Nonylphenols Nonylphenol heptaethoxylate (NP7EO) 0.00058 0.0000704 0.000261 0.0000316 μg/l 

Nonylphenols Nonylphenol hexadecaethoxylate (NP16EO) 0.000117 0.0000142 0.0000525 6.38E-06 μg/l 

Nonylphenols Nonylphenol hexaethoxylate (NP6EO) 0.000383 0.0000464 0.000172 0.0000209 μg/l 

Nonylphenols Nonylphenol nonaethoxylate (NP9EO) 0.000906 0.00011 0.000407 0.0000494 μg/l 

Nonylphenols Nonylphenol octaethoxylate (NP8EO) 0.000784 0.0000951 0.000352 0.0000428 μg/l 

Nonylphenols Nonylphenol octodecaethoxylate (NP18EO) 0.0000273 3.31E-06 0.0000123 1.49E-06 μg/l 

Nonylphenols Nonylphenol pendecaethoxylate (NP15EO) 0.000221 0.0000269 0.0000994 0.0000121 μg/l 

Nonylphenols Nonylphenol pentaethoxylate (NP5EO) 0.000195 0.0000237 0.0000878 0.0000107 μg/l 

Nonylphenols Nonylphenol tetradecaethoxylate (NP14EO) 0.000398 0.0000482 0.000179 0.0000217 μg/l 

Nonylphenols Nonylphenol tetraethoxylate (NP4EO) 0.0000567 6.88E-06 0.0000255 3.09E-06 μg/l 

Nonylphenols Nonylphenol tridecaethoxylate (NP13EO) 0.000604 0.0000733 0.000271 0.0000329 μg/l 

Nonylphenols Nonylphenol triethoxylate (NP3EO) 0.0000309 3.75E-06 0.0000139 1.69E-06 μg/l 

Nonylphenols Nonylphenol undecaethoxylate (NP11EO) 0.00105 0.000128 0.000473 0.0000574 μg/l 

Nonylphenols Octylphenol decaethoxylate (OP10EO) 0.0000274 3.32E-06 0.0000123 1.49E-06 μg/l 

Nonylphenols Octylphenol dodecaethoxylate (OP12EO) 0.0000125 1.52E-06 5.64E-06 6.84E-07 μg/l 

Nonylphenols Octylphenol heptaethoxylate (OP7EO) 8.24E-07 0.0000001 3.7E-07 4.49E-08 μg/l 

Nonylphenols Octylphenol nonaethoxylate (OP9EO) 0.0000102 1.24E-06 4.58E-06 5.56E-07 μg/l 

Nonylphenols Octylphenol octaethoxylate (OP8EO) 7.03E-06 8.53E-07 3.16E-06 3.83E-07 μg/l 

Nonylphenols Octylphenol undecaethoxylate (OP11EO) 0.0000165 0.000002 7.41E-06 8.99E-07 μg/l 

Nonylphenols Total Nonylphenol Polyethoxylates 0.00705 0.000856 0.00317 0.000385 μg/l 

Nonylphenols Total Nonylphenols 0.000025 3.03E-06 0.0000112 1.36E-06 μg/l 

VOC (2-Methyl-1-Propenyl)-Benzene 0.00234 0.000284 0.00105 0.000128 μg/l 

VOC (E)-1-Propenyl-Benzene 1.77E-06 2.15E-07 7.95E-07 9.65E-08 μg/l 

VOC (E)-2-Butenal 0.00428 0.00052 0.00192 0.000234 μg/l 

VOC 1,2,3,4-Tetrahydro-1-Methylnaphthalene 0.00269 0.000327 0.00121 0.000147 μg/l 

VOC 1,2,3,4-Tetrahydro-2-Methylnaphthalene 0.00248 0.000302 0.00112 0.000136 μg/l 

VOC 1,2,3,4-Tetrahydro-5-Methylnaphthalene 0.0218 0.00264 0.00978 0.00119 μg/l 

VOC 1,2,3,4-Tetrahydro-6-Ethylnaphthalene, 0.00235 0.000285 0.00105 0.000128 μg/l 

VOC 1,2,3,4-Tetrahydro-6-Methylnaphthalene 0.0198 0.0024 0.00888 0.00108 μg/l 

VOC 1,2,3,4-Tetrahydro-6-Methylnaphthalene (01) 0.00498 0.000605 0.00224 0.000272 μg/l 

G-46
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.7: Recreational Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

17 and 19 

Model 

Scenarios 

18 and 20 

Model 

Scenarios 

21 and 23 

Model 

Scenarios 

22 and 24 

Units 

VOC 1,2,3,4-Tetrahydro-6-Methylnaphthalene (02) 0.00417 0.000506 0.00187 0.000227 μg/l 

VOC 1,2,3,4-Tetrahydronaphthalene 0.0149 0.00181 0.00671 0.000814 μg/l 

VOC 1,2,3,4-Tetramethyl-Benzene 0.000702 0.0000853 0.000316 0.0000383 μg/l 

VOC 1,2,3,5-Tetramethyl-Benzene 0.00103 0.000125 0.000465 0.0000564 μg/l 

VOC 1,2,3-Trimethylbenzene 0.00338 0.00041 0.00152 0.000184 μg/l 

VOC 1,2,4,5-Tetramethylbenzene 0.00158 0.000191 0.000709 0.000086 μg/l 

VOC 1,2,4-Trimethylbenzene 0.00577 0.0007 0.00259 0.000315 μg/l 

VOC 1,3,5-Trimethylbenzene 0.00155 0.000189 0.000698 0.0000848 μg/l 

VOC 1,3-Methylnaphthalene 0.00307 0.000373 0.00138 0.000168 μg/l 

VOC 1,7-Methylnaphthalene 0.0139 0.00169 0.00625 0.000758 μg/l 

VOC 1-Ethyl-2,3-Dimethyl-Benzene (01) 0.00241 0.000293 0.00108 0.000131 μg/l 

VOC 1-Ethyl-2,3-Dimethyl-Benzene (02) 0.000429 0.0000521 0.000193 0.0000234 μg/l 

VOC 1-Ethyl-2,4-Dimethyl-Benzene 0.00167 0.000203 0.000751 0.0000912 μg/l 

VOC 1-Ethyl-2-Methyl-Benzene 5.46E-06 6.63E-07 2.45E-06 2.98E-07 μg/l 

VOC 1-Ethyl-3-Methyl-Benzene 0.00259 0.000314 0.00116 0.000141 μg/l 

VOC 1-Ethyl-4-Methyl-Benzene 0.00704 0.000855 0.00317 0.000384 μg/l 

VOC 1-Methyl-2-(1-Methylethyl)-Benzene 0 0 0 0 μg/l 

VOC 1-Methyl-2-(1-Methylethyl)-Benzene (01) 4.42E-06 5.37E-07 1.99E-06 2.41E-07 μg/l 

VOC 1-Methyl-2-(1-Methylethyl)-Benzene (02) 0.0000154 1.88E-06 6.94E-06 8.43E-07 μg/l 

VOC 1-Methyl-3-Propyl-Benzene 0.00137 0.000167 0.000617 0.0000749 μg/l 

VOC 1-Methyl-4-(1-Methylidene)-Cyclohexane 0 0 0 0 μg/l 

VOC 1-methyl-Indan 0.00651 0.00079 0.00292 0.000355 μg/l 

VOC 1-Propenyl-Benzene 2.03E-06 2.46E-07 9.12E-07 1.11E-07 μg/l 

VOC 2- Heptanone 0.0000656 7.96E-06 0.0000295 3.58E-06 μg/l 

VOC 2,3-Dihydro-1,2-Dimethyl-1H-Indene 0.000353 0.0000429 0.000159 0.0000193 μg/l 

VOC 2,3-Dihydro-1,6-Dimethyl-1H-Indene 0.00297 0.00036 0.00133 0.000162 μg/l 

VOC 2,3-Dihydro-1-Methylindene 0.00408 0.000495 0.00183 0.000223 μg/l 

VOC 2,3-Dihydro-1-methylindene (01) 0.00228 0.000276 0.00102 0.000124 μg/l 

VOC 2,3-Dihydro-1-methylindene (02) 0.00483 0.000586 0.00217 0.000263 μg/l 

VOC 2,3-Dihydro-4,7-Dimethyl-1H-Indene 0.0000134 1.63E-06 6.02E-06 7.31E-07 μg/l 

VOC 2,3-Dihydro-4-Methyl-1H-Indene 0.0436 0.00529 0.0196 0.00238 μg/l 

VOC 2,3-Dihydro-4-Methyl-1H-Indene (01) 6.29E-06 7.64E-07 2.83E-06 3.43E-07 μg/l 

VOC 2,3-Dihydro-4-Methyl-1H-Indene (02) 0.0000106 1.29E-06 4.77E-06 5.79E-07 μg/l 

VOC 2,3-Dihydro-5,6-dimethyl-1H-Indene 0.00221 0.000268 0.000992 0.00012 μg/l 

VOC 2,3-Dihydro-5-methyl-1H-Indene 0.00174 0.000211 0.00078 0.0000947 μg/l 

VOC 2,6-Dimethylnaphthalene 0.0302 0.00367 0.0136 0.00165 μg/l 

VOC 2-Butanone 0.0231 0.00281 0.0104 0.00126 μg/l 

VOC 2-Butenal 0.00267 0.000324 0.0012 0.000146 μg/l 

VOC 2-Ethyl-1,3,5-Trimethyl-Benzene 0.00322 0.000391 0.00145 0.000176 μg/l 

VOC 2-Ethyl-1,4-Dimethyl-Benzene 0.0149 0.00181 0.00669 0.000812 μg/l 

VOC 2-Ethyl-1-Hexanol 1.21E-06 1.47E-07 5.45E-07 6.62E-08 μg/l 

VOC 2-Ethyltoluene 0.00492 0.000597 0.00221 0.000268 μg/l 

VOC 2-Hexanone 0.00202 0.000246 0.00091 0.00011 μg/l 

VOC 2-Methyl-2-Propenal 0.00492 0.000597 0.00221 0.000268 μg/l 

VOC 2-Propenyl-Benzene 0.00514 0.000624 0.00231 0.000281 μg/l 

VOC 3-Buten-2-one 0.00452 0.000548 0.00203 0.000246 μg/l 

VOC 4-Ethyl-1,2-Dimethyl-Benzene 5.62E-06 6.82E-07 2.52E-06 3.06E-07 μg/l 

VOC 4-Heptanone 0.0000868 0.0000105 0.000039 4.74E-06 μg/l 

VOC 4-Isopropyltoluene 0.000689 0.0000836 0.000309 0.0000376 μg/l 

G-47
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.7: Recreational Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

17 and 19 

Model 

Scenarios 

18 and 20 

Model 

Scenarios 

21 and 23 

Model 

Scenarios 

22 and 24 

Units 

VOC 4-Methyl-2-Pentanone 0.000705 0.0000855 0.000317 0.0000384 μg/l 

VOC Acetaldehyde 0.0143 0.00173 0.00642 0.00078 μg/l 

VOC Acetone 0.103 0.0126 0.0465 0.00564 μg/l 

VOC Acrolein 0.00598 0.000726 0.00269 0.000326 μg/l 

VOC Benzaldehyde 0.000186 0.0000226 0.0000838 0.0000102 μg/l 

VOC Benzene 0.00596 0.000723 0.00268 0.000325 μg/l 

VOC Benzocycloheptatriene 0.0285 0.00346 0.0128 0.00156 μg/l 

VOC Benzofuran 0.00289 0.000351 0.0013 0.000158 μg/l 

VOC Bromodichloromethane 4.54E-06 5.51E-07 2.04E-06 2.48E-07 μg/l 

VOC Butane 0.000569 0.0000691 0.000256 0.0000311 μg/l 

VOC Butyraldehyde 0.00349 0.000424 0.00157 0.00019 μg/l 

VOC Carbon disulfide 0.0000022 2.67E-07 9.88E-07 1.2E-07 μg/l 

VOC Chloroform 0.00192 0.000233 0.000862 0.000105 μg/l 

VOC cis-1,2-Dichloroethene 3.38E-06 4.1E-07 1.52E-06 1.84E-07 μg/l 

VOC Cyclohexane 0.0000723 8.78E-06 0.0000325 3.95E-06 μg/l 

VOC Dibromochloromethane 4.46E-06 5.41E-07 0.000002 2.43E-07 μg/l 

VOC Dimethocxymethane 0.00384 0.000466 0.00173 0.000209 μg/l 

VOC Ethanol 0.0000232 2.82E-06 0.0000104 1.27E-06 μg/l 

VOC Ethylbenzene 0.00219 0.000265 0.000982 0.000119 μg/l 

VOC Indene 0.0000308 3.74E-06 0.0000139 1.68E-06 μg/l 

VOC Isopropylbenzene 0.00107 0.00013 0.000482 0.0000585 μg/l 

VOC Limonene 0 0 0 0 μg/l 

VOC m,p-Xylene (Sum of Isomers) 0.00733 0.00089 0.0033 0.0004 μg/l 

VOC Methyl acetate 0.0015 0.000182 0.000672 0.0000816 μg/l 

VOC Methyl tertiary butyl ether (MTBE) 9.62E-06 1.17E-06 4.32E-06 5.25E-07 μg/l 

VOC Methylcyclohexane 0.0000656 7.97E-06 0.0000295 3.58E-06 μg/l 

VOC Methylene chloride 0.000376 0.0000456 0.000169 0.0000205 μg/l 

VOC n-Butylbenzene 0.000644 0.0000782 0.000289 0.0000351 μg/l 

VOC nitro-Methane 0.00214 0.00026 0.000961 0.000117 μg/l 

VOC Nonanal 1.44E-06 1.75E-07 6.47E-07 7.86E-08 μg/l 

VOC n-Propylbenzene 0.000626 0.000076 0.000281 0.0000341 μg/l 

VOC n-Valeraldehyde 0.00309 0.000375 0.00139 0.000169 μg/l 

VOC O-Xylene 0.00476 0.000578 0.00214 0.00026 μg/l 

VOC sec-Butylbenzene 0.00146 0.000177 0.000657 0.0000797 μg/l 

VOC Styrene 0.00112 0.000135 0.000501 0.0000608 μg/l 

VOC Sulfur dioxide 0.00316 0.000383 0.00142 0.000172 μg/l 

VOC Tetrachloroethene 2.54E-06 3.09E-07 1.14E-06 1.39E-07 μg/l 

VOC Toluene 0.00832 0.00101 0.00374 0.000454 μg/l 

VOC Trichloroethene 2.37E-06 2.87E-07 1.06E-06 1.29E-07 μg/l 

VOC Trichlorofluoromethane 0.00124 0.000151 0.000558 0.0000678 μg/l 

VOC Tridecane 0.00255 0.00031 0.00115 0.000139 μg/l 

VOC Unknown VOC 0.00308 0.000373 0.00138 0.000168 μg/l 

VOC Unknown VOC (01) 0.00223 0.000271 0.001 0.000122 μg/l 

VOC Unknown VOC (02) 0.00298 0.000362 0.00134 0.000163 μg/l 

VOC Unknown VOC (03) 0.00271 0.000328 0.00122 0.000148 μg/l 

VOC Unknown VOC (04) 0.00175 0.000213 0.000788 0.0000957 μg/l 

VOC Unknown VOC (05) 0.00161 0.000195 0.000722 0.0000877 μg/l 

VOC Vinyl acetate 0.00159 0.000193 0.000714 0.0000867 μg/l 

SVOC (E)-2-Tetradecene 0.0000776 9.42E-06 0.0000349 4.23E-06 μg/l 

G-48
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.7: Recreational Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

17 and 19 

Model 

Scenarios 

18 and 20 

Model 

Scenarios 

21 and 23 

Model 

Scenarios 

22 and 24 

Units 

SVOC 1,2,3,4-Tetrahydro-2,7-Dimethylnaphthalene 0.000184 0.0000224 0.0000828 0.0000101 μg/l 

SVOC 1,2,3-Trichloro-(Z)-1-Propene 0.000054 6.55E-06 0.0000243 2.95E-06 μg/l 

SVOC 1,2,3-Trimethylbenzene (1) 0.000786 0.0000954 0.000353 0.0000429 μg/l 

SVOC 1,2,3-Trimethylbenzene (2) 0.001 0.000122 0.00045 0.0000546 μg/l 

SVOC 1,2,4,5-Tetramethylbenzene (1) 0.00011 0.0000134 0.0000494 0.000006 μg/l 

SVOC 1,2,4,5-Tetramethylbenzene (2) 0.000102 0.0000124 0.0000459 5.57E-06 μg/l 

SVOC 1,2-Diethyl-Cyclobutane 0.00731 0.000888 0.00329 0.000399 μg/l 

SVOC 1,3-Dimethylnaphthalene 0.0000269 3.27E-06 0.0000121 1.47E-06 μg/l 

SVOC 1,3-Dimethylnaphthalene (01) 0.00415 0.000503 0.00186 0.000226 μg/l 

SVOC 1,4-Dimethyl-1,2,3,4-tetrahydronaphthalene 0.00613 0.000745 0.00276 0.000335 μg/l 

SVOC 1,4-Dimethylnaphthalene 0.00668 0.000811 0.003 0.000364 μg/l 

SVOC 1,4-Dimethylnaphthalene (01) 0.0044 0.000533 0.00198 0.00024 μg/l 

SVOC 1,5-Dimethylnaphthalene 0.000664 0.0000806 0.000298 0.0000362 μg/l 

SVOC 1,6-Dimethylnaphthalene 0.0311 0.00377 0.014 0.00169 μg/l 

SVOC 1,7,7-tri-(methyl)-bicyclo[2.2.1]heptane 0 0 0 0 μg/l 

SVOC 1-Dodecanol 0.000029 3.51E-06 0.000013 1.58E-06 μg/l 

SVOC 1-Hexadecene 2.68E-06 3.26E-07 1.21E-06 1.46E-07 μg/l 

SVOC 1-Methyl-2-Propyl-Benzene (01) 0.000828 0.000101 0.000372 0.0000452 μg/l 

SVOC 1-Methyl-2-Propyl-Benzene (02) 0.000239 0.000029 0.000108 0.0000131 μg/l 

SVOC 1-Methylnaphthalene 0.0281 0.00341 0.0126 0.00153 μg/l 

SVOC 1-Phenyl-1-Butene 1.56E-06 1.89E-07 7.01E-07 8.51E-08 μg/l 

SVOC 2-(dodecyloxy)-Ethanol 0.0000362 4.39E-06 0.0000163 1.97E-06 μg/l 

SVOC 2-(hexadecyloxy)-Ethanol 9.29E-06 1.13E-06 4.18E-06 5.07E-07 μg/l 

SVOC 2-(tetradecyloxy)-Ethanol 0.0000268 3.26E-06 0.0000121 1.46E-06 μg/l 

SVOC 2,3-Dimethylnaphthalene 0.00541 0.000657 0.00243 0.000295 μg/l 

SVOC 2,4,6-Trichlorophenol 0.0000112 1.35E-06 5.01E-06 6.08E-07 μg/l 

SVOC 2,4-Dimethyl-Benzaldehyde 0.0000029 3.52E-07 0.0000013 1.58E-07 μg/l 

SVOC 2,4-Dimethylphenol 0.00154 0.000187 0.000693 0.0000841 μg/l 

SVOC 2,6,10,14-Tetramethyl Pentadecane 0.00965 0.00117 0.00434 0.000526 μg/l 

SVOC 2,6,10,14-Tetramethylhexadecae 0.0065 0.000789 0.00292 0.000355 μg/l 

SVOC 2,6,10,14-Tetramethylhexadecae (01) 0.000292 0.0000354 0.000131 0.0000159 μg/l 

SVOC 2,6-dimethyl-Heptadecane 0.0106 0.00129 0.00477 0.000578 μg/l 

SVOC 2,7-Dimethylnaphthalene 0.0075 0.000911 0.00337 0.000409 μg/l 

SVOC 2-Cyclopenten1-one 0.00073 0.0000886 0.000328 0.0000398 μg/l 

SVOC 2-Ethyl-Hexanoic acid 0.103 0.0125 0.0465 0.00564 μg/l 

SVOC 2-Hydroxy-Benzaldehyde 0.0112 0.00136 0.00505 0.000613 μg/l 

SVOC 2-Mercaptobenzothiazole 0 0 0 0 μg/l 

SVOC 2-Methyl Tridecane 0.000154 0.0000187 0.0000694 8.42E-06 μg/l 

SVOC 2-Methyl-Benzaldehyde 0.00478 0.00058 0.00215 0.000261 μg/l 

SVOC 2-Methyl-Dodecane 0.0000384 4.66E-06 0.0000172 2.09E-06 μg/l 

SVOC 2-Methylnaphthalene 0.036 0.00437 0.0162 0.00196 μg/l 

SVOC 2-Naphthalenecarboxaldehyde 0.000799 0.0000969 0.000359 0.0000436 μg/l 

SVOC 3,4-Dimethylphenol 1.36E-06 1.65E-07 6.12E-07 7.43E-08 μg/l 

SVOC 3,5-Dimethyl-Benzaldehyde 1.76E-06 2.14E-07 7.92E-07 9.62E-08 μg/l 

SVOC 3,6-Dimethylundecane 5.59E-07 6.79E-08 2.51E-07 3.05E-08 μg/l 

SVOC 3-Methyl-Benzaldehyde 0.0102 0.00123 0.00456 0.000554 μg/l 

SVOC 3-Methyl-Benzaldehyde (01) 0.0114 0.00138 0.00512 0.000621 μg/l 

SVOC 3-Methyl-butanoic acid 0.0000917 0.0000111 0.0000412 0.000005 μg/l 

SVOC 3-Methyl-Phenanthrene 0.00476 0.000578 0.00214 0.00026 μg/l 

G-49
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

Appendix G.7: Recreational Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

17 and 19 

Model 

Scenarios 

18 and 20 

Model 

Scenarios 

21 and 23 

Model 

Scenarios 

22 and 24 

Units 

SVOC 3-Methylphenol 0.000532 0.0000646 0.000239 0.000029 μg/l 

SVOC 3-Phenyl-2-Propenal 0.000359 0.0000436 0.000162 0.0000196 μg/l 

SVOC 4,4-Dimethylbiphenyl 0.00495 0.000601 0.00222 0.00027 μg/l 

SVOC 4-Hydroxy-2-Butanone 0.00554 0.000673 0.00249 0.000302 μg/l 

SVOC 4-Methyl-1H-Benzotriazole 5.58E-06 6.77E-07 2.51E-06 3.04E-07 μg/l 

SVOC 4-METHYL-PENTANOIC ACID 0.0000611 7.42E-06 0.0000275 3.34E-06 μg/l 

SVOC 5-Butyl-Hexadecane 4.31E-07 5.23E-08 1.94E-07 2.35E-08 μg/l 

SVOC 5-Methyl-2-(1-methyl)-Cyclohexanol 7.58E-06 9.2E-07 3.41E-06 4.13E-07 μg/l 

SVOC 9-Methyl-9H-Fluorene 0.00509 0.000618 0.00229 0.000278 μg/l 

SVOC Acenaphthylene 0.00275 0.000334 0.00124 0.00015 μg/l 

SVOC Acetophenone 0.0000146 1.77E-06 6.55E-06 7.94E-07 μg/l 

SVOC Benzeneacetic Acid 0.0000467 5.66E-06 0.000021 2.55E-06 μg/l 

SVOC Benzenepropanoic Acid 0.0000515 6.25E-06 0.0000231 2.81E-06 μg/l 

SVOC Benzothiazole 0.0000239 0.0000029 0.0000107 0.0000013 μg/l 

SVOC Benzyl alcohol 0.0000152 1.85E-06 6.84E-06 8.3E-07 μg/l 

SVOC Biphenyl 0.00273 0.000331 0.00122 0.000149 μg/l 

SVOC Bis(2-ethylhexyl) phthalate 0.00114 0.000138 0.000511 0.000062 μg/l 

SVOC Caprolactam 0.0000273 3.32E-06 0.0000123 1.49E-06 μg/l 

SVOC Cholesterol 0.000142 0.0000172 0.0000636 7.72E-06 μg/l 

SVOC Cyclic octaatomic sulfur 0.012 0.00146 0.00539 0.000654 μg/l 

SVOC Cyclodecane 0.0000795 9.64E-06 0.0000357 4.33E-06 μg/l 

SVOC Cyclododecane 0.0000296 3.59E-06 0.0000133 1.61E-06 μg/l 

SVOC Cyclotetradecane 0.0000158 1.92E-06 7.12E-06 8.64E-07 μg/l 

SVOC Diethene Glycol Monododecyl Ether 0.0000299 3.62E-06 0.0000134 1.63E-06 μg/l 

SVOC Dimethyl phthalate 0.0000651 0.0000079 0.0000292 3.55E-06 μg/l 

SVOC Di-n-butyl phthalate 0.00139 0.000168 0.000624 0.0000757 μg/l 

SVOC Di-n-octyl phthalate 0.0000571 6.94E-06 0.0000257 3.12E-06 μg/l 

SVOC Disopropylene glycol 8.81E-06 1.07E-06 3.96E-06 4.8E-07 μg/l 

SVOC Dodecane 3.21E-07 3.9E-08 1.44E-07 1.75E-08 μg/l 

SVOC Dodecanoic acid 0.0000217 2.63E-06 9.74E-06 1.18E-06 μg/l 

SVOC Eicosane 0.0243 0.00295 0.0109 0.00133 μg/l 

SVOC Ethanol, 2,2-oxybis- 0.000974 0.000118 0.000438 0.0000531 μg/l 

SVOC Ethanol, 2-Butoxy 0.00619 0.000752 0.00278 0.000338 μg/l 

SVOC Fluorene 0.00294 0.000356 0.00132 0.00016 μg/l 

SVOC Heneicosane 0.00744 0.000903 0.00334 0.000406 μg/l 

SVOC Heptadecane 0.0429 0.00521 0.0193 0.00234 μg/l 

SVOC Hexaethylene Glycol Monododecyl 0.0000182 2.21E-06 8.17E-06 9.91E-07 μg/l 

SVOC Hexaethylene Glycol Monododecyl (01) 7.28E-06 8.84E-07 3.27E-06 3.97E-07 μg/l 

SVOC Hexaethylene Glycol Monododecyl (02) 0.0000023 2.79E-07 1.03E-06 1.25E-07 μg/l 

SVOC Hexagol 0.0000105 1.27E-06 4.71E-06 5.72E-07 μg/l 

SVOC Indane 0.000858 0.000104 0.000386 0.0000468 μg/l 

SVOC Indole 0.000257 0.0000313 0.000116 0.000014 μg/l 

SVOC Isopropylbenzene-4,methyl-1 0 0 0 0 μg/l 

SVOC m-Cresol 0.0000245 2.98E-06 0.000011 1.34E-06 μg/l 

SVOC Naphthalene 0.0133 0.00161 0.00596 0.000723 μg/l 

SVOC N-Butyl-Benzenesulfonamide 0.000003 3.64E-07 1.35E-06 1.64E-07 μg/l 

SVOC n-Hexadecane 0.0408 0.00495 0.0183 0.00223 μg/l 

SVOC n-Hexadecanoic acid 0.0000153 1.86E-06 6.89E-06 8.36E-07 μg/l 

SVOC Nonadecane 0.033 0.00401 0.0148 0.0018 μg/l 

G-50
Appendix G – Supporting Information for EPA’s Screening-Level Water Quality Model 

G-51

Appendix G.7: Recreational Harbor Vessel Scenarios Instantaneous Concentration in the 

Hypothetical Harbor 

Class Analyte 

Model 

Scenarios 

17 and 19 

Model 

Scenarios 

18 and 20 

Model 

Scenarios 

21 and 23 

Model 

Scenarios 

22 and 24 

Units 

SVOC Nonadecane (01) 0.0102 0.00124 0.00459 0.000557 μg/l 

SVOC Nonanoic Acid 0.00805 0.000977 0.00362 0.000439 μg/l 

SVOC n-Pentadecane 0.0316 0.00383 0.0142 0.00172 μg/l 

SVOC n-Tetradecane 0.039 0.00474 0.0175 0.00213 μg/l 

SVOC o-Cresol 0.00457 0.000555 0.00205 0.000249 μg/l 

SVOC Octadecane 0.0093 0.00113 0.00418 0.000508 μg/l 

SVOC p-Cresol 0.0136 0.00165 0.00612 0.000743 μg/l 

SVOC Pentacosane 0.000266 0.0000323 0.000119 0.0000145 μg/l 

SVOC Pentaethene Glycol Monododecyl Ether 2.46E-06 2.98E-07 0.0000011 1.34E-07 μg/l 

SVOC Pentaethene Glycol Monododecyl Ether (01) 0.000018 2.18E-06 8.07E-06 9.8E-07 μg/l 

SVOC Pentaethene Glycol Monododecyl Ether (02) 0.0000354 4.29E-06 0.0000159 1.93E-06 μg/l 

SVOC Phenanthrene 0.0025 0.000303 0.00112 0.000136 μg/l 

SVOC Phenol 0.0279 0.00339 0.0126 0.00152 μg/l 

SVOC Phthalic acid, isobutyl octyl ester 0.0000102 1.24E-06 0.0000046 5.58E-07 μg/l 

SVOC Pyrene 0.000125 0.0000151 0.0000561 6.81E-06 μg/l 

SVOC Sulfur 0.00346 0.00042 0.00156 0.000189 μg/l 

SVOC Tetraethylene glycol monododecyl ether 0.0000183 2.22E-06 8.23E-06 9.99E-07 μg/l 

SVOC Triethyl phosphate 0.0000422 5.13E-06 0.000019 0.0000023 μg/l 

SVOC Triethylene glycol monododecyl ether 0.0000272 0.0000033 0.0000122 1.48E-06 μg/l 

SVOC Unknown SVOC 0.00742 0.0009 0.00333 0.000405 μg/l 

SVOC Unknown SVOC (01) 0.00681 0.000826 0.00306 0.000371 μg/l 

SVOC Unknown SVOC (02) 0.0072 0.000874 0.00324 0.000393 μg/l 

SVOC Unknown SVOC (03) 0.000288 0.0000349 0.000129 0.0000157 μg/l 

SVOC Unknown SVOC (04) 0.000295 0.0000359 0.000133 0.0000161 μg/l 

SVOC Unknown SVOC (05) 0.000166 0.0000202 0.0000748 9.08E-06 μg/l 

SVOC Unknown SVOC (06) 0.000103 0.0000125 0.0000464 5.63E-06 μg/l 

SVOC Unknown SVOC (07) 0.00154 0.000187 0.000692 0.000084 μg/l 

(1) EPA suspects a limited number of the samples analyzed for selenium (even fewer for arsenic) for bilgewater, 

packing gland effluent, propulsion engine effluent, graywater and deck washdown water may be positively 

influenced (increased) by interference from high concentrations of major cations in the sample matrix. Although 

EPA suspects that the highest concentrations of dissolved arsenic (and to a lesser extent selenium) in fish hold 

effluent from a shrimping vessel could be slightly elevated due to cation interference; EPA believes the fish hold 

concentrations reasonably represent true effluent concentrations for the discharge (see Section 3.2.4.1). EPA 

considered these interferences when interpreting the potential for vessel discharges to pose a risk to human health, 

aquatic life, or the environment and determined that such cationic interference does not influence the major findings 

presented in the modeling analysis.
Appendix H – Responsiveness Summary 

Appendix H 

Responsiveness Summary 

EPA received 24 separate comment letters from 23 different commenters. These 

included 19 trade associations (Alaska Longline Fishermen’s Association, Alaska 

Trollers Association, American Coatings Association, American Waterways Operators, 

Boat U.S., California Wetfish Producers Association, two comments from Conference of 

Professional Operators for Response Towing (C-PORT), Garden State Seafood 

Association, National Association of Charterboats, National Marine Manufacturers 

Association, Offshore Marine Service Association, Passenger Vessel Association, 

Recreational Fishing Alliance – South Carolina Chapter, Sefood Producers Coop, 

Southeast Alaska Fishermen’s Alliance, United Cook Inlet Drift Association (UCIDA), 

the United Fishermen of Alaska, and West Coast Seafood Processors Association), 4 

vessel operators or businesses (3 in Alaska or the Pacific Northwest, 1 in New Jersey) 

and 1 state agency (Alaska Department of Environmental Conservation). EPA 

considered the comments received in finalizing the Report and thanks these commenters 

for providing us with their feedback on the report. We have summarized significant or 

reoccurring comments below. 

COMMENT: 

Some commenters noted that EPA did not sample a sufficient number of vessels. 

RESPONSE: 

EPA believes that the dataset used to characterize discharges from nonrecreational 

vessels less than 79 feet in length and all commercial fishing vessels regardless of length 

is from a representative cross-section of vessels and is adequate to evaluate the vessel 

population. In conducting this study, EPA worked with 14 trade associations and 27 

individual companies to obtain information regarding the shipboard processes, 

equipment, materials, and operations that contribute to the discharges, as well as the 

discharge rates, duration, frequency, and location. 

EPA collected samples of nine vessel discharges from a total of 61 vessels (one to four 

discharges sampled per vessel) in nine vessel classes to characterize discharge pollutant 

concentrations and flow. These vessels were located in 15 different towns/cities in nine 

separate states, representing several of the major regions of the United States. 

In preparing the Report to Congress, EPA used all of the technically appropriate data 

provided by industry and collected from EPA’s vessel sampling program. EPA released 

the pre publication version of the draft report to congress to the public on March 2, 2010 

(announced in the March 8th Federal Register Notice (75 FR 10477)) and solicited 

comment on all aspects of the report as well as specific comment on the existence of 

additional data or data sources. As previously discussed, EPA received 24 separate 

comment letters from 23 different commenters, including 19 trade associations, 4 vessel 

operators or businesses, and 1 state agency. EPA evaluated the comments and 

H-1
Appendix H – Responsiveness Summary 

information received and revised the draft report to incorporate additional technically 

appropriate information. EPA believes that the final report is based on adequate EPAgathered and industry-supplied data, which includes primary sampling data and an 

extensive review of existing peer-reviewed literature and other government reports.

COMMENT: 

Several commenters questioned the representativeness of the sampled vessels, 

particularly for commercial fishing vessels. 

RESPONSE: 

EPA believes that the dataset used to characterize discharges from nonrecreational 

vessels less than 79 feet in length and all commercial fishing vessels regardless of length, 

including sampling data from 61 vessels, is from a representative cross-section of vessels 

and is adequate for the purposes of this national, screening-level evaluation. EPA 

sampled vessels from each of the nine most common vessel classes and sampled more 

commercial fishing vessels (33 vessels) than any other vessel class due to the large 

number of fishing vessels in the P.L. 110-299 study universe. EPA notes that additional 

sampling to characterize the less common vessel classes/types and discharges would not 

influence the major findings of this study as the total discharge volume from these vessels 

are an insignificant portion of discharges from the total industry population. Given that 

EPA has limited data with which to base this study, EPA’s approach is reasonable. 

In response to comments, EPA further evaluated the representativeness of the sampled 

commercial fishing vessels by comparing their size, class, and geographic distribution to 

those of the overall industry population. 

Size. The following table compares the size distribution of the sampled vessels to the 

total industry population. 

Percentage of Vessels 

Vessel Length 

Sampled Commercial 

Fishing Vessel Population 

Overall Commercial 

Fishing Vessel Population*

Less than 26 feet 0% 10% 

26 to 50 feet 52% 70% 

50 to 79 feet 39% 16% 

79 feet or more 9% 4% 

* – Size distribution of those vessels that reported vessel length in the U.S. Coast Guard 

MISLE Database, 2009. 

Commenters noted, and EPA concurs, that the sampled commercial fishing vessel 

population does not represent discharges from vessels less than 26 feet in length. EPA 

observed that these small vessels typically store their catch in coolers (which do not have 

a discharge) rather than in refrigerated seawater or ice holding tanks, as allowed by their 

relatively short fishing voyages. EPA attempted to interview small commercial fishing 

vessel captains to obtain information on fishing operations and discharges; however, none 

of the contacted vessel captains volunteered their vessels to remain at the pier long 

H-2
Appendix H – Responsiveness Summary 

enough for EPA to collect information or to sample their holding tanks (if any), but rather 

offloaded their catch within a few minutes (e.g., physically transferred bushels of crabs or 

lobsters from the cooler to the dock) and immediately returned to the fishing grounds. 

For the remaining categories of vessel length, the sampled vessel population reasonably 

agrees with the overall vessel population, albeit somewhat more heavily weighted toward 

the largest of commercial fishing vessels (i.e., 50 feet or more) as compared to the overall 

vessel population. Again, due to the time required to collect the necessary data, captains 

of larger vessels were more willing to participate in the study because they had more time 

shoreside during large offloads than the captains of smaller vessels. 

In summary, with the exception of the smallest commercial fishing vessels, EPA believes 

that the sampled vessel population is a representative cross-section of vessels and is 

adequate to evaluate the vessel population for the purpose of this study. With respect to 

small vessels, as a conservative estimate, EPA assumed vessel discharge characteristics 

for small vessels similar to those of larger vessels. 

Class. The following table compares the distribution by vessel class for the sampled 

fishing vessel types to the total industry population. 

Percentage of Vessels 

Vessel Class 

Sampled Commercial 

Fishing Vessel Population 

Overall Commercial 

Fishing Vessel Population*

Gillnetter 15% 9% 

Pot/Trap 3%1 27% 

Longliner 9% 6% 

Seiner 15% 2% 

Shrimper/Scalloper/Dredge 18% 23% 

Tender 9% <1% 

Trawler 12% 12% 

Troller/Hook and Line 18% 19% 

* – Vessel class distribution of those vessels that reported vessel subtype in the U.S. 

Coast Guard MISLE Database, 2009. 

EPA’s sampled commercial fishing vessel population includes vessels in all of the fishing 

vessel classes. Furthermore, the percentage of sampled vessels by class is similar to or 

greater than the percentage of the overall vessel population by class for all vessel classes 

except for Pot/Trap vessels. Pot/Trap vessels include many of the smallest commercial 

vessels that are not represented by EPA’s sampled vessel population as discussed above, 

and in general have flow-through seawater holding tanks used to keep crabs and lobsters 

alive until reaching the seafood processing facility. As such, discharges from seafood 

holding tanks on Pot/Trap vessels are generally seawater. EPA also notes that it sampled 

a much larger percentage of seiners than the overall vessel population (15% of vessels 

sampled versus only 2% of the overall vessel population). EPA sampled all vessels 

 

1

 EPA did sample a lobster hold tank on a 63-foot trawler. 

H-3
Appendix H – Responsiveness Summary 

(where the permission of the captains was granted) that arrived at the docks at the 

seafood processors while the EPA sampling crew was at the docks. Sampling in Sitka, 

AK occurred at the start of the salmon fishing season, resulting in a preponderance of 

Seiners at the docks of seafood processers. 

In summary, with the possible exception of Pot/Trap vessels, EPA believes that the 

sampled vessel population is a representative cross-section of vessels and is adequate to 

evaluate the vessel population for the purpose of this study. With respect to Seiners, fish 

hold effluent analyte concentrations from these vessels were neither the lowest nor the 

highest among the fish hold effluent discharged by the sampled vessel population. 

Therefore, EPA believes that any overrepresentation of Seiner fish hold effluent in EPA’s 

analyses of vessel discharges would provide neither a high nor low bias to EPA’s 

findings or conclusions. 

Geographic Distribution. EPA sampled commercial fishing vessels in the following 

regions: Alaska (21 vessels); Gulf Coast (6 vessels); and New England (6 vessels). 

According to the National Marine Fisheries Service2, in 2008 Alaska had nearly 55% of 

U.S. domestic commercial landings; the Gulf Coast had approximately 15% of U.S. 

domestic commercial landings; and New England had just over 7% of U.S. domestic 

commercial landings. Combined, these three areas represent approximately 77% of U.S. 

domestic commercial landings in 2008. Among the remaining geographic regions that 

EPA was unable to sample, the Pacific Coast (excluding Alaska) has the greatest landings 

in 2008 at 13%; commercials fishing vessels in this region are expected to be similar to 

those in Alaska. Finally, many of other remaining geographic regions that EPA was 

unable to sample, such as Chesapeake, Middle Atlantic, Great Lakes, and Hawaii, are 

likely dominated by small fishing vessels that may not have fish hold effluent discharges. 

Therefore, EPA believes that the geographic distribution of the sampled vessel population 

is a representative cross-section of vessels and is adequate to evaluate the vessel 

population for the purpose of this study. 

COMMENT: 

Some commenters noted that the assumptions used for estimating discharge volumes for 

the screening-level water quality model (Chapter 4 of the Report to Congress) resulted in 

higher estimates of volumes discharged. For example, commenters noted that some 

commercial fishing vessels do not clean their hulls daily or empty their holds daily. 

RESPONSE: 

Based on review and analysis of the comments, EPA ran a supplemental model run with 

the adjusted model assumptions presented in the table below and recalculated the 

associated discharge flows and loads. EPA performed this supplemental model run using 

the revised values to assess the impacts on the model results. EPA observed no 

significant change in model results based on the revised values. EPA revised Chapter 4 to 

describe this supplemental model run and to present the findings. 

 

2

 National Marine Fisheries Service (NMFS). 2009. Fisheries of the United States 2008. NMFS Fisheries 

Statistics Division. Silver Spring, MD. 

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Appendix H – Responsiveness Summary 

Revised Model Assumptions 

Vessel 

Class 

Vessel 

Subclass Discharge Old Assumption New Assumption 

Fishing Gillnetter Fish Hold Offloads daily Offloads once per five days 

Fishing Longliner Fish Hold Offloads once per two 

days 

Offloads once per five days 

Fishing Toller Fish Hold Clean Offloads daily Offloads once per seven 

days 

Fishing Toller Fish Hold Offloads daily Offloads once per seven 

days 

Fishing Toller Fish Hold 840 ft3 fish hold 595 ft3 fish hold 

Fishing Toller Fish Hold 5.5 tons of ice per offload 2 tons of ice per offload 

Fishing Toller Deck Wash 125 gallons per deck 

wash 

50 gallons per deck wash 

Fishing Shrimping Bilge Water 150 gallons per minute 

bilge pump rate 

20 gallons per minute bilge 

pump rate 

Tour Boat NA Bilge Water 14.3 gallons per day 5 gallons per day 

COMMENT: 

Many commenters noted that some vessels do not have discharge types discussed in the 

report, for example, towing vessels do not have fish hold waste. 

RESPONSE: 

EPA agrees with this statement and believes that this point is clear in the report when 

describing discharge types. Furthermore, in its model, EPA estimates certain discharge 

types to occur from only some vessels. 

COMMENT: 

Some commenters noted that too few vessels, or too few vessels of a certain vessel type 

were sampled. For example, one commenter stated that EPA should have sampled 

charter fishing vessels. Others stated that EPA should have sampled different types of 

vessels than those selected. 

RESPONSE:

See above response to comment regarding the sufficiency of the number of vessels 

sampled. Charter fishing vessels are often manufactured or used primarily for pleasure, or 

leased, rented or chartered to a person for the pleasure of that person. Many are not 

inspected by the US Coast Guard. Charter fishing vessels which are not inspected are 

exempted form NPDES permitting requirements by the Clean Boating Act (P.L. 110-

288). Other charter fishing vessels are inspected by the US Coast Guard. These 

inspected, non-recreational vessels are not exempted from NPDES by the Clean Boating 

Act and are study vessels. Charter fishing vessels were not one of the most common 

vessels seen by EPA in its sampling program and the opportunity to sample charter 

fishing vessels did not present itself during the course of EPA’s sampling. 

COMMENT: 

Some commenters noted that the MISLE database is not a completely accurate database 

for estimating vessel numbers or vessel location. 

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Appendix H – Responsiveness Summary 

RESPONSE: 

EPA agrees that use of the database may result in shortcomings. For example, the 

database under- or overcounts certain categories of vessels due to gaps in documentation 

or reporting requirements, differences in how the categories are defined, or missing 

information. Additionally, while a vessel may list New Orleans as its hailing port, it may 

rarely, if ever, operate in waters in and around New Orleans. However, based on its 

research, EPA concluded that the MISLE database was the best source of information for 

estimating the numbers and locations of study vessels. Several commenters pointed EPA 

to other databases. EPA reviewed these sources of information, and qualified the data in 

Chapter 1 of the report where appropriate. 

Specifically, commenters raised concerns regarding estimates provided for two particular 

categories of vessels – passenger vessels and tank and freight barges – for which they 

believed MISLE misrepresents the number of active vessels less than 79 feet in length. 

EPA reviewed the MISLE database records and used additional information to further 

qualify the estimates presented in the report. For example, EPA revised the report to (1) 

detail the various types of vessels included in each category where the category definition 

differed from the types of vessels mentioned by commenters; (2) emphasize and further 

clarify limitations and potential shortcomings of the analyses; and (3) where possible, 

present ranges rather than unique estimates for the number of in-scope vessels. 

In general, while EPA agrees that information provided by the MISLE database is 

uncertain, subject to potential errors and omissions, or potentially outdated, the Agency 

believes that this source still provides the most complete data available on vessel 

characteristics, particularly for smaller undocumented vessels which are of key concern 

in this study. EPA consulted with U.S. Coast Guard personnel on the estimates presented 

in the report and compared numbers obtained from MISLE with those presented in other 

sources, when such sources are available. No other public database provides the same 

breadth of information, however, from which to develop estimates of the number or 

characteristics of study vessels. 

COMMENT: 

Several commenters recommended that EPA analyze data on a regional basis, particularly 

for discharges from commercial fishing vessels. 

RESPONSE: 

Based on public comments received on EPA’s Draft version of this report, EPA 

conducted a regional analysis of vessel fish hold discharges. While the preliminary 

analysis does suggest potential regional differences, issues with small sample size and an 

unbalanced distribution of vessels across regions suggest that additional sampling would 

be required to make a definitive determination. This regional analysis, which also 

includes additional analyses to determine the degree to which regional differences were 

an artifact of differences in vessel type (fishing method), or discharge type (refrigerated 

water vs. ice vs. ice slurry) are now included as a new subsection within the fish hold 

discharge section in Chapter 3 of the report. 

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Appendix H – Responsiveness Summary 

COMMENT: 

Some commenters noted that EPA should distinguish between different types of fish hold 

effluent in the analytical results. For example, one commenter stated that the Agency 

needed to more clearly distinguish between the discharge of refrigerated seawater and sea 

ice or sea ice slurry. Other commenters noted that EPA needed to more clearly 

distinguish between fish hold discharge and fish hold cleaning discharge. 

RESPONSE: 

In response to the first comment (distinguishing results between types of discharge 

(refrigerated vs. sea ice or sea ice slurry), EPA conducted additional screening analyses. 

EPA conducted an analysis comparing potential differences between refrigerated 

seawater, sea ice, or sea ice slurry. Differences in the type of fish hold discharge were 

separately investigated both for all 26 vessels included in this study and for the 20 vessels 

from Alaska. In both instances, there were no statistically significant differences between 

fish hold discharges between vessels as a function of whether the discharge was 

refrigerated seawater, ice, or ice slurry. These analyses are discussed within the regional 

analysis section within the fish hold discharge section in Chapter 3 of the Report. 

EPA disagrees with the second comment because the data presented in the report clearly 

indicate few, if any, distinguishable differences between results obtained for fish hold and 

fish hold cleaning discharge, and where those differences occur, EPA discusses them in 

text. 

COMMENT:

One commenter noted that the report is not conducted on recreational vessels and that the 

report needs to be clearer to this effect. Other commenters noted that the potential 

cumulative environmental impacts from all study vessels should be compared to the 

potential cumulative environmental impacts from all recreational vessels. 

RESPONSE: 

EPA believes the report is clear that the vast majority of samples are from vessels which 

were not in recreational service. However, two vessels sampled were recreational 

vessels, while discharges from several others were fundamentally similar to those which 

may originate from recreational vessels (e.g., engine effluent from certain towing 

vessels). 

For purposes of this study, EPA does not believe that the cumulative impact of study 

vessels should be compared to those of recreational vessels, as an analysis of this kind is 

beyond the original congressional charge and beyond the original scope of the study 

design. 

 

COMMENT: 

Some commenters noted that EPA should examine the impacts of invasive species from 

recreational vessels, or what would happen if EPA were to prohibit practices designed to 

reduce the transport of invasive species (e.g., anti-foulant hull coatings). A commenter 

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Appendix H – Responsiveness Summary 

noted that EPA should add additional references to the impact of invasive species caused 

by boating, specifically in the absence of cuprous oxide anti-foulant hull coatings. 

RESPONSE: 

EPA and EPA scientists, among others have conducted numerous studies on the impacts 

of invasive species. EPA further discusses the impacts of invasive species in regulatory 

documents such as the fact sheet and other supporting documents for its recently issued 

Vessel General Permit. EPA agrees with the commenter that the risks of increasing the 

likelihood of invasive species being transported needs to be weighed against any 

regulatory limits placed on discharges. However, this report does not make 

recommendations regarding regulatory limits or best management practices. 

COMMENT: 

Two commenters noted that EPA needed to further research and clarify its statements 

regarding anti-foulant paints. 

RESPONSE: 

One commenter noted that the issue of invasive species was inadequately discussed in 

relationship to the regulation of anti-foulant coatings (AFCs). As discussed in the 

previous response, the focus of the study was not on invasive species. Additionally, 

based on comments regarding AFCs, EPA removed one sentence: “On the other hand, 

improvements to water quality, including improvements associated with AFC restrictions 

and BMPs may allow native ecosystems to recover from acute and chronic impacts and 

become more resistant to invasions of non-native species” attributed to Johnson and 

Gonzalez (2006), which appeared to be speculative. 

Additional test data for copper AFC leaching rates were provided to EPA by the 

Antifouling Coatings Work Group (AFWG) of the American Coatings Association 

(ACA) during the public comment period. EPA added a footnote in Section 3.2.8 

acknowledging receipt of additional test data for copper AFC leaching rates, and noted 

that this data substantially agrees with EPA's "best estimate" of copper AFC leaching rate 

used for water quality modeling. 

One commenter noted that statements regarding the regulation of AFCs in other countries 

were misleading and/or incorrect. Upon review, EPA found that the regulation of AFCs 

in Europe and other countries are dynamic and evolving. Therefore, EPA elected to 

remove the text in question, which appeared to be outdated. 

COMMENT: 

One commenter noted that EPA needs to clarify in the executive summary that the 

National Recommended Water Quality Criteria (NRWQC) benchmarks used are 

conservative in nature. 

RESPONSE: 

EPA disagrees and feels the information provided in Chapter 3 on the NRWQC 

benchmarks is clear. This level of detail is not appropriate for discussion in a short 

executive summary. 

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Appendix H – Responsiveness Summary 

COMMENT: 

Some commenters stated that they believed the release or leaching of metals or other 

biocides from hull coatings did not constitute a discharge. 

RESPONSE: 

EPA disagrees, and would consider these releases as discharges from the vessel. EPA 

has consistently determined that the release of metals or leaching of metals or other 

biocides constitutes the addition of pollutants from a point source to waters of the United 

States, i.e., a discharge. (See EPA’s 2008 Vessel General Permit or Uniform National 

Discharge Standards (UNDS) Phase I rule and CWA section 502). The CWA definition 

of “point source” includes “vessel or other floating craft.” 

COMMENT: 

One commenter noted that EPA should clearly distinguish between commercial fishing 

vessels and charter fishing vessels. The commenter also noted that charter fishing vessels 

are more similar to recreational vessels than many of their commercial fishing 

counterparts. 

RESPONSE: 

The charter fishing vessels discussed by these commenters may fall under the definition 

of recreational vessel as defined in the Clean Boating Act of 2008. Charter fishing 

vessels are often manufactured or used primarily for pleasure, or leased, rented, or 

chartered to a person for the pleasure of that person. Many are not inspected by the US 

Coast Guard. Charter fishing vessels which are not inspected are exempted form NPDES 

permitting requirements by the Clean Boating Act (P.L. 110-288). Other charter fishing 

vessels are inspected by the US Coast Guard. These inspected, non-recreational vessels 

are not exempted from NPDES by the Clean Boating Act, and are study vessels,. EPA 

did not sample any charter fishing vessels as part of the sampling program. 

In addition to sampling two recreational vessels, EPA studied several recreational vessels 

used for non-recreational purposes as part of the study (some tow/salvage boats and 

research vessels). Vessel discharges such as engine effluent are likely fundamentally 

similar to the engine effluent between the two vessel classes, provided they are similar 

engine types and maintained in a similar manner. 

COMMENT: 

Several commenters noted that they recommended Congress continue to extend the P.L. 

110-299 moratorium or that Congress devise an alternate regulatory program. For 

example, several commenters noted that commercial fishing vessels less than 79 feet 

should be regulated similarly to those under the Clean Boating Act of 2008 (P.L. 110-

288). Other commenters requested exemptions from NPDES permitting or any permit 

EPA may promulgate under the NPDES permitting program for smaller commercial 

fishing vessels. 

H-9
Appendix H – Responsiveness Summary 

H-10

RESPONSE: 

On July 30, 2010, President Obama signed Senate Bill S. 3372 to extend an existing 

moratorium from July 31, 2010 to December 18, 2013. This moratorium exempts all 

incidental discharges except ballast water from commercial fishing vessels and nonrecreational vessels less than 79 feet from having to obtain an NPDES permit. 

EPA notes that this is not the proper forum for requesting that the Agency grant 

exemptions to certain classes of vessels from the NPDES program. Please see discussion 

in the 2008 VGP Fact Sheet for additional information about why EPA now regulates 

certain vessel discharges and for additional information on Congressional legislation that 

did grant permanent exemptions to certain types of vessels. 

COMMENT: 

One commenter requested an extension of time to review the report and provide further 

comments. 

RESPONSE: 

Due to the short time granted to EPA to conduct the study, EPA believes it would be 

inappropriate to grant any extensions to review the report as the Agency wants the final 

report to be available for congressional decision makers and others as soon as possible. 
Appendix I – List of Preparers and Contributors 

Appendix I 

List of Preparers and Contributors 

Ryan Albert, Office of Water, EPA 

Robin Danesi, Office of Water, EPA 

Erin Saylor, Office of Water, EPA 

Sean Ramach, EPA Region 5 

Marcus Zobrist, Office of Water, EPA 

Jill Bloom, Office of Prevention, Pesticides, and Toxic Substances 

Brian Rappoli, Office of Water, EPA 

Renee Searafoss, EPA Region 3 

Tyler Linton, Great Lakes Environmental Center 

Doug Endicott, Great Lakes Environmental Center 

Keith Taulbee, Great Lakes Environmental Center 

Michelle Moore, Great Lakes Environmental Center 

Debra Falatko, Eastern Research Group 

Mark Briggs, Eastern Research Group 

Kathleen Wu, Eastern Research Group 

Kristi Bibb, Eastern Research Group 

Isabelle Morin, Abt Associates 

Lauren Tikusis, Abt Associates 

Laboratory Support and Analyses: 

John Bourbon, EPA Region 2 

John Lee, EPA Region 2 

Maria Javier, EPA Region 2 

William Rickert, EPA Region 2 

Renee Lettieri, EPA Region 2 

Jamie Hale, EPA Region 2 

Deborah Kay, EPA Region 2 

Cindy Caporale, EPA Region 3 

Sue Warner, EPA Region 3 

Dave Russell, EPA Region 3 

Robin Costas, EPA Region 3 

Joe Dorsey, EPA Region 3 

John Curry, EPA Region 3 

Ron Altman, EPA Region 3 

Norman Fritsche, EPA Region 3 

Kevin Poff, EPA Region 3 

Kevin Martin, EPA Region 3 

Larry Zintec, EPA Region 5 

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