National Summary of Impaired Waters and TMDL Information

Map of the United States Alabama Alaska American Samoa Arizona Arkansas California Colorado Connecticut Delaware Washington, DC Florida Georgia Guam Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachussets Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Northern Mariana Islands Ohio Oklahoma Oregon Pennsylvania Puerto Rico Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virgin Islands Virginia Washington West Virginia Wisconsin Wyoming

Depicted below are national summary tables and charts for available water quality data reported by the States to EPA under Section 305(b) and 303(d) of the Clean Water Act.

This report displays the most current available reporting year data.
Check the Status of Available Data for more information.




Impaired Waters Listed By State

Description of this table
State Name Number of Waters on 303(d) List
Alabama color.gif 220
Alaska color.gif 35
American Samoa color.gif 45
Arizona color.gif 90
Arkansas color.gif 225
California color.gif 1,052
Colorado color.gif 293
Connecticut color.gif 286
Delaware color.gif 101
District Of Columbia color.gif 36
Florida color.gif 2,292
Georgia color.gif 242
Guam color.gif 47
Hawaii color.gif 352
Idaho color.gif 741
Illinois color.gif 1,057
Indiana color.gif 1,836
Iowa color.gif 571
Kansas color.gif 1,372
Kentucky color.gif 1,433
Louisiana color.gif 236
Maine color.gif 113
Maryland color.gif 337
Massachusetts color.gif 720
Michigan color.gif 2,584
Minnesota color.gif 1,592
Mississippi color.gif 261
Missouri color.gif 270
Montana color.gif 480
N. Mariana Islands color.gif 24
Nebraska color.gif 342
Nevada color.gif 210
New Hampshire color.gif 1,449
New Jersey color.gif 710
New Mexico color.gif 237
New York color.gif 611
North Carolina color.gif 1,152
North Dakota color.gif 217
Ohio color.gif 267
Oklahoma color.gif 635
Oregon color.gif 1,397
Pennsylvania color.gif 6,957
Puerto Rico color.gif 195
Rhode Island color.gif 121
South Carolina color.gif 907
South Dakota color.gif 166
Tennessee color.gif 1,012
Texas color.gif 719
Utah color.gif 156
Vermont color.gif 101
Virgin Islands color.gif 87
Virginia color.gif 1,490
Washington color.gif 2,420
West Virginia color.gif 1,097
Wisconsin color.gif 663
Wyoming color.gif 107

Total: 42,368 impaired waters


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Causes of Impairment for 303(d) Listed Waters

Description of this table
NOTE: Click on a cause of impairment (e.g. pathogens) to see the specific state-reported causes that are grouped to make up this category. Click on the "Number of Causes of Impairment Reported" to see a list of waters with that cause of impairment.
Cause of Impairment Group Name Number of Causes of Impairment Reported
Pathogens color.gif 10,292
Nutrients color.gif 7,166
Metals (other than Mercury) color.gif 6,972
Organic Enrichment/Oxygen Depletion color.gif 6,423
Polychlorinated Biphenyls (PCBs) color.gif 6,061
Sediment color.gif 5,993
Mercury color.gif 4,476
pH/Acidity/Caustic Conditions color.gif 4,299
Cause Unknown - Impaired Biota color.gif 4,063
Temperature color.gif 3,024
Turbidity color.gif 2,910
Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 1,866
Pesticides color.gif 1,739
Cause Unknown color.gif 1,138
Algal Growth color.gif 1,036
Habitat Alterations color.gif 824
Dioxins color.gif 560
Total Toxics color.gif 464
Toxic Organics color.gif 437
Ammonia color.gif 394
Toxic Inorganics color.gif 373
Other Cause color.gif 254
Oil and Grease color.gif 135
Flow Alteration(s) color.gif 99
Fish Consumption Advisory color.gif 98
Taste, Color and Odor color.gif 89
Biotoxins color.gif 82
Noxious Aquatic Plants color.gif 68
Trash color.gif 67
Cause Unknown - Fish Kills color.gif 61
Radiation color.gif 52
Chlorine color.gif 49
Nuisance Exotic Species color.gif 34
Nuisance Native Species color.gif 4

Total: 71,602 Causes of Impairment

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National Cumulative TMDLs by Pollutant

This chart includes TMDLs since October 1, 1995.

Description of this table
NOTE: Click on the underlined "Pollutant Group" value to see a detailed list of pollutants. Click on the underlined "Number of TMDLs" value to see a listing of those TMDLs for the pollutant Group.
Pollutant Group Number of TMDLs Number of Causes of
Impairment Addressed
Mercury color.gif 21,545 21,575
Pathogens color.gif 13,263 13,572
Metals (other than Mercury) color.gif 9,955 10,153
Nutrients color.gif 6,161 7,529
Sediment color.gif 3,942 4,593
Temperature color.gif 2,329 2,339
Organic Enrichment/Oxygen Depletion color.gif 2,191 2,315
pH/Acidity/Caustic Conditions color.gif 1,958 2,017
Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 1,715 1,773
Turbidity color.gif 1,603 1,829
Pesticides color.gif 1,351 1,514
Ammonia color.gif 1,131 1,230
Polychlorinated Biphenyls (PCBs) color.gif 500 520
Chlorine color.gif 335 341
Other Cause color.gif 268 323
Toxic Inorganics color.gif 206 206
Toxic Organics color.gif 158 199
Cause Unknown - Impaired Biota color.gif 128 132
Total Toxics color.gif 120 130
Algal Growth color.gif 95 103
Habitat Alterations color.gif 83 84
Trash color.gif 75 75
Dioxins color.gif 27 28
Noxious Aquatic Plants color.gif 21 22
Radiation color.gif 19 22
Oil and Grease color.gif 14 14
Cause Unknown color.gif 7 7
Nuisance Exotic Species color.gif 3 6
Fish Consumption Advisory color.gif 2 2

Total: 69,205 TMDLs; 72,653 Causes of Impairment Addressed

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Approved TMDLs By State

This chart includes TMDLs since October 1, 1995.

Description of this table
NOTE: Click on the state name to see a state report. Click on the Number of TMDLs to see a detailed list of the TMDLs.
State Name Number of TMDLs
Alabama color.gif 305
Alaska color.gif 60
American Samoa color.gif 43
Arizona color.gif 88
Arkansas color.gif 318
California color.gif 2,013
Colorado color.gif 1,016
Connecticut color.gif 407
Delaware color.gif 581
District Of Columbia color.gif 385
Florida color.gif 2,246
Georgia color.gif 1,700
Guam color.gif 43
Hawaii color.gif 65
Idaho color.gif 2,211
Illinois color.gif 429
Indiana color.gif 1,305
Iowa color.gif 217
Kansas color.gif 3,335
Kentucky color.gif 345
Louisiana color.gif 750
Maine color.gif 341
Maryland color.gif 830
Massachusetts color.gif 609
Michigan color.gif 238
Minnesota color.gif 1,802
Mississippi color.gif 1,440
Missouri color.gif 288
Montana color.gif 1,444
Nebraska color.gif 171
Nevada color.gif 67
New Hampshire color.gif 6,055
New Jersey color.gif 616
New Mexico color.gif 344
New York color.gif 719
North Carolina color.gif 13,443
North Dakota color.gif 137
Ohio color.gif 1,761
Oklahoma color.gif 704
Oregon color.gif 1,241
Pennsylvania color.gif 7,152
Puerto Rico color.gif 321
Rhode Island color.gif 217
South Carolina color.gif 524
South Dakota color.gif 329
Tennessee color.gif 1,276
Texas color.gif 268
Utah color.gif 324
Vermont color.gif 119
Virgin Islands color.gif 66
Virginia color.gif 1,489
Washington color.gif 1,500
West Virginia color.gif 4,867
Wisconsin color.gif 247
Wyoming color.gif 394

Total: 69,205 TMDLs


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National Cumulative Number of TMDLs

EPA Fiscal Year starts October 1 and ends September 30.


Description of this table
NOTE: Click on the underlined "Number of TMDLs Completed" value for a detailed list of the TMDLs for the fiscal year.
Fiscal Year Number of TMDLs Number of Causes of
Impairment Addressed
1996 color.gif 135 136
1997 color.gif 337 351
1998 color.gif 402 408
1999 color.gif 330 373
2000 color.gif 1,558 1,585
2001 color.gif 2,581 2,617
2002 color.gif 2,735 2,815
2003 color.gif 3,008 3,281
2004 color.gif 3,393 3,651
2005 color.gif 4,319 4,634
2006 color.gif 4,206 4,557
2007 color.gif 4,321 4,651
2008 color.gif 9,264 9,546
2009 color.gif 4,399 4,623
2010 color.gif 2,572 2,708
2011 color.gif 2,830 3,113
2012 color.gif 2,883 3,151
2013 color.gif 15,534 15,624
2014 color.gif 3,338 3,511
2015 color.gif 945 1,068
2016 color.gif 115 250

Total: 69,205 TMDLs; 72,653 Causes of Impairment Addressed

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Status of Available Data Used in This Report

Description of this table
State Name Assessed Waters Report Year Impaired Waters Report Year
Alabama 2014 2014
Alaska 2010 2010
American Samoa 2014 2014
Arizona 2010 2010
Arkansas 2008 2008
California 2012 2012
Colorado 2012 2012
Connecticut 2014 2014
Delaware 2006 2006
District Of Columbia 2014 2014
Florida 2010 2010
Georgia 2012 2012
Guam 2010 2010
Hawaii 2014 2014
Idaho 2012 2012
Illinois 2010 2006
Indiana 2010 2008
Iowa 2012 2014
Kansas 2014 2014
Kentucky 2012 2012
Louisiana 2012 2012
Maine 2012 2012
Maryland 2012 2012
Massachusetts 2012 2012
Michigan 2010 2010
Minnesota 2012 2012
Mississippi 2014 2014
Missouri 2014 2014
Montana 2014 2014
N. Mariana Islands 2014 2014
Nebraska 2014 2014
Nevada 2012 2012
New Hampshire 2010 2010
New Jersey 2012 2012
New Mexico 2014 2014
New York 2014 2014
North Carolina 2014 2014
North Dakota 2014 2014
Ohio 2010 2008
Oklahoma 2014 2014
Oregon 2006 2006
Pennsylvania 2006 2004
Puerto Rico 2014 2014
Rhode Island 2014 2014
South Carolina 2012 2012
South Dakota 2014 2014
Tennessee 2012 2012
Texas 2010 2010
Utah 2010 2010
Vermont 2014 2014
Virgin Islands 2012 2012
Virginia 2014 2012
Washington 2008 2008
West Virginia 2010 2010
Wisconsin 2006 2008
Wyoming 2012 2012


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