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National Summary of State Information

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.

Assessed Waters of United States

Incomplete state reported information may lead to discrepancies and/or missing information in these reports.

	Size of Water
	Rivers and Streams (Miles)	Lakes, Reservoirs, and Ponds (Acres)	Bays and Estuaries (Square Miles)	Coastal Shoreline (Miles)	Ocean and Near Coastal (Square Miles)	Wetlands (Acres)	Great Lakes Shoreline (Miles)	Great Lakes Open Water (Square Miles)
Good Waters	449,617	5,865,232	11,045	1,746	968	208,944	78	62
Threatened Waters	6,369	38,681	17			805
Impaired Waters	514,795	13,038,033	21,776	7,263	815	1,107,261	4,353	53,270
Total Assessed Waters	970,781	18,941,946	32,838	9,010	1,783	1,317,011	4,431	53,332
Total Waters	3,533,205	41,666,049	87,791	58,618	54,120	107,700,000	5,202	60,546
Percent of Waters Assessed	27.5	45.5	37.4	15.4	3.3	1.2	85.2	88.1

States Using a Statewide Statistical Survey

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Summary of Water Quality Assessments for Each Waterbody Type

National Summary
Water Quality Attainment in Assessed Rivers and Streams

Description of this table Assessed Status Miles Assessed 970,781 Unassessed 2,562,424 Total Miles 3,533,205

Description of this table Attainment Status Miles Good 449,617 Threatened 6,369 Impaired 514,795 Total Miles Assessed 970,781

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National Summary
Designated Use Support in Assessed Rivers and Streams*

* Waters assessed for more than one designated use are included in multiple designated use groups below.

Designated Use Group		Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Fish, Shellfish, And Wildlife Protection And Propagation	762,113	55.0	.5	44.5
	Recreation	390,603	55.2	1.4	43.3
	Agricultural	351,971	93.7	.6	5.8
	Aquatic Life Harvesting	261,832	34.0	.3	65.7
	Industrial	210,190	93.3	.0	6.7
	Public Water Supply	187,707	73.9	.8	25.3
	Other	99,646	84.5	.3	15.3
	Aesthetic Value	26,064	89.0	.0	11.0
	Exceptional Recreational Or Ecological Significance	14,663	11.3	4.4	84.4

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National Summary
Causes of Impairment in Assessed Rivers and Streams

Cause of Impairment Group	Miles Threatened or Impaired
Pathogens	157,823
Sediment	106,057
Nutrients	101,241
Organic Enrichment/Oxygen Depletion	87,675
Polychlorinated Biphenyls (PCBs)	76,405
Habitat Alterations	75,578
Metals (other than Mercury)	72,335
Mercury	61,995
Flow Alteration(s)	50,479
Temperature	50,166
Cause Unknown	39,587
Cause Unknown - Impaired Biota	37,783
Salinity/Total Dissolved Solids/Chlorides/Sulfates	32,493
pH/Acidity/Caustic Conditions	29,330
Turbidity	28,124
Pesticides	17,097
Other Cause	17,082
Ammonia	12,701
Fish Consumption Advisory	10,029
Algal Growth	7,492
Total Toxics	7,226
Toxic Inorganics	6,834
Toxic Organics	4,886
Dioxins	4,318
Oil and Grease	2,740
Cause Unknown - Fish Kills	1,371
Nuisance Exotic Species	1,236
Taste, Color and Odor	925
Radiation	652
Chlorine	629
Noxious Aquatic Plants	295
Trash	238
Nuisance Native Species	127
Biotoxins	84

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National Summary
Probable Sources of Impairments in Assessed Rivers and Streams

Probable Source Group	Miles Threatened or Impaired
Agriculture	123,620
Atmospheric Deposition	101,015
Unknown	87,574
Hydromodification	58,915
Urban-Related Runoff/Stormwater	51,517
Natural/Wildlife	51,375
Municipal Discharges/Sewage	50,762
Unspecified Nonpoint Source	46,985
Habitat Alterations (Not Directly Related To Hydromodification)	32,415
Resource Extraction	26,264
Silviculture (Forestry)	19,444
Industrial	14,179
Construction	13,522
Other	10,170
Land Application/Waste Sites/Tanks	8,228
Legacy/Historical Pollutants	4,888
Spills/Dumping	2,420
Recreation And Tourism (Non-Boating)	1,741
Aquaculture	318
Groundwater Loadings/Withdrawals	178
Recreational Boating And Marinas	132
Military Bases	42

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National Summary
Water Quality Attainment in Assessed Lakes, Reservoirs, and Ponds

Description of this table Assessed Status Acres Assessed 18,941,946 Unassessed 22,724,103 Total Acres 41,666,049

Description of this table Attainment Status Acres Good 5,865,232 Threatened 38,681 Impaired 13,038,033 Total Acres Assessed 18,941,946

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National Summary
Designated Use Support in Assessed Lakes, Reservoirs, and Ponds*

* Waters assessed for more than one designated use are included in multiple designated use groups below.

Designated Use Group		Acres Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Aquatic Life Harvesting	10,812,453	25.0	.5	74.5
	Fish, Shellfish, And Wildlife Protection And Propagation	10,713,506	54.7	.3	45.0
	Recreation	9,030,545	74.5	2.4	23.1
	Public Water Supply	7,082,568	76.3	.6	23.1
	Agricultural	5,343,556	90.4	.7	8.8
	Industrial	4,395,330	89.1	.1	10.8
	Other	3,210,515	69.7	.3	30.0
	Aesthetic Value	1,203,314	52.9	.0	47.1
	Exceptional Recreational Or Ecological Significance	732,768	16.1	15.6	68.3

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National Summary
Causes of Impairment in Assessed Lakes, Reservoirs, and Ponds

Cause of Impairment Group	Acres Threatened or Impaired
Mercury	7,449,617
Nutrients	3,567,824
Polychlorinated Biphenyls (PCBs)	2,839,876
Organic Enrichment/Oxygen Depletion	1,732,490
Metals (other than Mercury)	1,525,067
Turbidity	1,372,795
Algal Growth	1,220,553
pH/Acidity/Caustic Conditions	886,936
Sediment	718,144
Nuisance Exotic Species	680,604
Flow Alteration(s)	548,980
Pathogens	544,163
Fish Consumption Advisory	488,727
Salinity/Total Dissolved Solids/Chlorides/Sulfates	481,009
Habitat Alterations	443,402
Pesticides	352,495
Nuisance Native Species	272,318
Other Cause	270,437
Ammonia	210,127
Temperature	202,660
Taste, Color and Odor	147,143
Dioxins	119,568
Toxic Organics	94,686
Cause Unknown	60,496
Cause Unknown - Impaired Biota	58,062
Radiation	48,312
Noxious Aquatic Plants	45,734
Total Toxics	23,556
Biotoxins	17,258
Toxic Inorganics	8,035
Cause Unknown - Fish Kills	6,457
Trash	1,717
Oil and Grease	1,274

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National Summary
Probable Sources of Impairments in Assessed Lakes, Reservoirs, and Ponds

Probable Source Group	Acres Threatened or Impaired
Atmospheric Deposition	4,804,255
Unknown	3,199,251
Agriculture	1,821,113
Natural/Wildlife	1,355,736
Hydromodification	907,651
Other	867,056
Urban-Related Runoff/Stormwater	858,186
Municipal Discharges/Sewage	813,637
Legacy/Historical Pollutants	769,768
Unspecified Nonpoint Source	759,087
Resource Extraction	563,235
Habitat Alterations (Not Directly Related To Hydromodification)	360,800
Construction	319,470
Silviculture (Forestry)	242,583
Industrial	224,021
Spills/Dumping	194,422
Recreational Boating And Marinas	126,413
Commercial Harbor And Port Activities	109,240
Recreation And Tourism (Non-Boating)	107,766
Groundwater Loadings/Withdrawals	98,032
Land Application/Waste Sites/Tanks	77,106
Aquaculture	4,620
Military Bases	2,436

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National Summary
Water Quality Attainment in Assessed Bays and Estuaries

Description of this table Assessed Status Square Miles Assessed 32,838 Unassessed 54,953 Total Square Miles 87,791

Description of this table Attainment Status Square Miles Good 11,045 Threatened 17 Impaired 21,776 Total Square Miles Assessed 32,838

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National Summary
Designated Use Support in Assessed Bays and Estuaries*

* Waters assessed for more than one designated use are included in multiple designated use groups below.

Designated Use Group		Square Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Aquatic Life Harvesting	24,483	31.4	.1	68.5
	Fish, Shellfish, And Wildlife Protection And Propagation	19,409	52.1	.1	47.8
	Recreation	13,997	91.6	.0	8.4
	Agricultural	3,976	96.3	.0	3.7
	Industrial	3,766	96.1	.0	3.9
	Other	3,432	92.7	.0	7.3
	Exceptional Recreational Or Ecological Significance	533	.8	.0	99.2
	Public Water Supply	328	47.8	.0	52.2
	Aesthetic Value	114	86.6	.0	13.4

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National Summary
Causes of Impairment in Assessed Bays and Estuaries

Cause of Impairment Group	Square Miles Threatened or Impaired
Mercury	10,433
Pathogens	6,581
Polychlorinated Biphenyls (PCBs)	6,483
Organic Enrichment/Oxygen Depletion	5,217
Dioxins	3,896
Metals (other than Mercury)	1,975
Noxious Aquatic Plants	1,855
Pesticides	1,778
Algal Growth	1,412
Cause Unknown - Impaired Biota	1,160
Toxic Organics	925
Nutrients	882
Other Cause	782
Turbidity	378
Total Toxics	316
Flow Alteration(s)	299
Habitat Alterations	262
Sediment	199
Nuisance Exotic Species	92
pH/Acidity/Caustic Conditions	92
Cause Unknown	53
Temperature	35
Trash	31
Ammonia	31
Oil and Grease	16
Toxic Inorganics	6
Taste, Color and Odor	6
Salinity/Total Dissolved Solids/Chlorides/Sulfates	5

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National Summary
Probable Sources of Impairments in Assessed Bays and Estuaries

Probable Source Group	Square Miles Threatened or Impaired
Atmospheric Deposition	7,731
Unknown	5,447
Municipal Discharges/Sewage	4,406
Natural/Wildlife	4,225
Industrial	3,760
Other	3,630
Agriculture	3,028
Unspecified Nonpoint Source	2,607
Hydromodification	2,513
Habitat Alterations (Not Directly Related To Hydromodification)	2,057
Urban-Related Runoff/Stormwater	1,877
Legacy/Historical Pollutants	1,469
Resource Extraction	1,292
Recreational Boating And Marinas	1,053
Commercial Harbor And Port Activities	470
Groundwater Loadings/Withdrawals	158
Land Application/Waste Sites/Tanks	52
Spills/Dumping	26
Construction	16
Land Application/Waste Sites	1
Recreation And Tourism (Non-Boating)	0
Silviculture (Forestry)	0
Aquaculture	0

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National Summary
Water Quality Attainment in Assessed Coastal Shoreline

Description of this table Assessed Status Miles Assessed 9,010 Unassessed 49,608 Total Miles 58,618

Description of this table Attainment Status Miles Good 1,746 Threatened 0 Impaired 7,263 Total Miles Assessed 9,010

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National Summary
Designated Use Support in Assessed Coastal Shoreline*

* Waters assessed for more than one designated use are included in multiple designated use groups below.

Designated Use Group		Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Aquatic Life Harvesting	8,027	14.8	.0	85.2
	Recreation	2,183	78.6	.0	21.4
	Fish, Shellfish, And Wildlife Protection And Propagation	1,516	75.4	.0	24.6
	Other	680	73.9	.0	26.1
	Exceptional Recreational Or Ecological Significance	328	80.1	.0	19.9
	Industrial	308	78.2	.0	21.8
	Aesthetic Value	235	100.0	.0	.0
	Agricultural	50	.0	.0	100.0
	Public Water Supply	49	.0	.0	100.0

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National Summary
Causes of Impairment in Assessed Coastal Shoreline

Cause of Impairment Group	Miles Threatened or Impaired
Mercury	6,473
Pathogens	1,114
Organic Enrichment/Oxygen Depletion	423
Metals (other than Mercury)	214
Turbidity	129
Nutrients	123
Algal Growth	91
Pesticides	71
Cause Unknown - Impaired Biota	70
pH/Acidity/Caustic Conditions	69
Other Cause	65
Polychlorinated Biphenyls (PCBs)	35
Ammonia	21
Temperature	20
Toxic Organics	13
Oil and Grease	13
Sediment	5

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National Summary
Probable Sources of Impairments in Assessed Coastal Shoreline

Probable Source Group	Miles Threatened or Impaired
Unknown	427
Atmospheric Deposition	388
Municipal Discharges/Sewage	326
Urban-Related Runoff/Stormwater	270
Agriculture	142
Hydromodification	136
Industrial	127
Unspecified Nonpoint Source	120
Natural/Wildlife	100
Recreational Boating And Marinas	36
Other	34
Construction	23
Commercial Harbor And Port Activities	20
Recreation And Tourism (Non-Boating)	20
Spills/Dumping	13
Land Application/Waste Sites/Tanks	12
Resource Extraction	12
Legacy/Historical Pollutants	8
Aquaculture	5

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National Summary
Water Quality Attainment in Assessed Ocean and Near Coastal

Description of this table Assessed Status Square Miles Assessed 1,783 Unassessed 52,337 Total Square Miles 54,120

Description of this table Attainment Status Square Miles Good 968 Threatened 0 Impaired 815 Total Square Miles Assessed 1,783

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National Summary
Designated Use Support in Assessed Ocean and Near Coastal*

* Waters assessed for more than one designated use are included in multiple designated use groups below.

Designated Use Group		Square Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Recreation	1,336	97.6	.0	2.4
	Fish, Shellfish, And Wildlife Protection And Propagation	1,329	59.0	.0	41.0
	Aquatic Life Harvesting	1,069	45.5	.0	54.5
	Other	476	57.8	.0	42.2
	Public Water Supply	154	100.0	.0	.0
	Exceptional Recreational Or Ecological Significance	99	100.0	.0	.0
	Industrial	3	100.0	.0	.0

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National Summary
Causes of Impairment in Assessed Ocean and Near Coastal

Cause of Impairment Group	Square Miles Threatened or Impaired
Mercury	595
Organic Enrichment/Oxygen Depletion	579
Polychlorinated Biphenyls (PCBs)	531
Pesticides	525
Pathogens	80
Nuisance Exotic Species	35
Total Toxics	29
Turbidity	22
Metals (other than Mercury)	15
Toxic Organics	14
Habitat Alterations	10
Dioxins	9
Nutrients	7
pH/Acidity/Caustic Conditions	7
Temperature	1
Ammonia	1

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National Summary
Probable Sources of Impairments in Assessed Ocean and Near Coastal

Probable Source Group	Square Miles Threatened or Impaired
Atmospheric Deposition	576
Unknown	560
Urban-Related Runoff/Stormwater	452
Municipal Discharges/Sewage	116
Recreational Boating And Marinas	9
Unspecified Nonpoint Source	7
Recreation And Tourism (Non-Boating)	4
Industrial	4
Hydromodification	4
Construction	3
Spills/Dumping	2
Natural/Wildlife	1
Commercial Harbor And Port Activities	0

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National Summary
Water Quality Attainment in Assessed Wetlands

Description of this table Assessed Status Acres Assessed 1,317,011 Unassessed 106,382,989 Total Acres 107,700,000

Description of this table Attainment Status Acres Good 208,944 Threatened 805 Impaired 1,107,261 Total Acres Assessed 1,317,011

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National Summary
Designated Use Support in Assessed Wetlands*

* Waters assessed for more than one designated use are included in multiple designated use groups below.

Designated Use Group		Acres Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Fish, Shellfish, And Wildlife Protection And Propagation	1,310,226	15.6	.1	84.3
	Recreation	1,135,615	51.7	5.9	42.4
	Public Water Supply	543,566	88.3	.0	11.7
	Exceptional Recreational Or Ecological Significance	141,544	8.3	44.6	47.2
	Aquatic Life Harvesting	97,041	.3	.0	99.7
	Industrial	82,390	23.1	.0	76.9
	Other	67,123	1.1	.0	98.9
	Agricultural	30,331	53.6	.6	45.7

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National Summary
Causes of Impairment in Assessed Wetlands

Cause of Impairment Group	Acres Threatened or Impaired
Organic Enrichment/Oxygen Depletion	926,402
Pathogens	476,087
Mercury	231,152
Metals (other than Mercury)	170,731
Habitat Alterations	107,432
Nutrients	68,593
Flow Alteration(s)	32,260
Toxic Inorganics	28,097
Total Toxics	12,659
Sediment	11,405
Salinity/Total Dissolved Solids/Chlorides/Sulfates	8,518
Temperature	7,680
Turbidity	4,089
Algal Growth	3,891
Nuisance Exotic Species	2,988
Cause Unknown - Impaired Biota	1,263
Cause Unknown	1,000
Fish Consumption Advisory	1,000
Cause Unknown - Fish Kills	997
Noxious Aquatic Plants	940
pH/Acidity/Caustic Conditions	838
Polychlorinated Biphenyls (PCBs)	707
Other Cause	678
Trash	458
Pesticides	362
Toxic Organics	133
Radiation	2

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National Summary
Probable Sources of Impairments in Assessed Wetlands

Probable Source Group	Acres Threatened or Impaired
Unknown	707,582
Natural/Wildlife	563,032
Municipal Discharges/Sewage	464,479
Agriculture	369,637
Atmospheric Deposition	200,741
Industrial	195,840
Hydromodification	109,024
Resource Extraction	94,719
Other	65,874
Unspecified Nonpoint Source	63,901
Construction	13,971
Habitat Alterations (Not Directly Related To Hydromodification)	8,017
Groundwater Loadings/Withdrawals	3,045
Land Application/Waste Sites/Tanks	1,634
Recreation And Tourism (Non-Boating)	787
Urban-Related Runoff/Stormwater	2
Silviculture (Forestry)	2

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National Summary
Water Quality Attainment in Assessed Great Lakes Shoreline

Description of this table Assessed Status Miles Assessed 4,431 Unassessed 772 Total Miles 5,202

Description of this table Attainment Status Miles Good 78 Threatened 0 Impaired 4,353 Total Miles Assessed 4,431

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National Summary
Designated Use Support in Assessed Great Lakes Shoreline*

* Waters assessed for more than one designated use are included in multiple designated use groups below.

Designated Use Group		Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Aquatic Life Harvesting	4,064	.0	.0	100.0
	Agricultural	3,131	100.0	.0	.0
	Other	3,131	100.0	.0	.0
	Industrial	3,131	100.0	.0	.0
	Fish, Shellfish, And Wildlife Protection And Propagation	865	33.1	.0	66.9
	Recreation	816	32.2	.0	67.8
	Public Water Supply	336	100.0	.0	.0

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National Summary
Causes of Impairment in Assessed Great Lakes Shoreline

Cause of Impairment Group	Miles Threatened or Impaired
Polychlorinated Biphenyls (PCBs)	3,472
Dioxins	2,963
Mercury	2,194
Pesticides	1,975
Pathogens	492
Nutrients	315
Nuisance Exotic Species	290
Sediment	290
Fish Consumption Advisory	285
Habitat Alterations	170
Other Cause	152
Organic Enrichment/Oxygen Depletion	120
Algal Growth	25
Toxic Inorganics	5

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National Summary
Probable Sources of Impairments in Assessed Great Lakes Shoreline

Probable Source Group	Miles Threatened or Impaired
Atmospheric Deposition	3,400
Agriculture	536
Legacy/Historical Pollutants	427
Unknown	141
Municipal Discharges/Sewage	120
Land Application/Waste Sites/Tanks	31
Industrial	31
Unspecified Nonpoint Source	8
Hydromodification	7
Urban-Related Runoff/Stormwater	2
Natural/Wildlife	0

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National Summary
Water Quality Attainment in Assessed Great Lakes Open Water

Description of this table Assessed Status Square Miles Assessed 53,332 Unassessed 7,214 Total Square Miles 60,546

Description of this table Attainment Status Square Miles Good 62 Threatened 0 Impaired 53,270 Total Square Miles Assessed 53,332

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National Summary
Designated Use Support in Assessed Great Lakes Open Water*

* Waters assessed for more than one designated use are included in multiple designated use groups below.

Designated Use Group		Square Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Aquatic Life Harvesting	39,184	.0	.0	100.0
	Agricultural	39,031	100.0	.0	.0
	Other	39,031	100.0	.0	.0
	Industrial	39,031	100.0	.0	.0
	Fish, Shellfish, And Wildlife Protection And Propagation	14,300	1.5	.0	98.5
	Public Water Supply	151	100.0	.0	.0
	Recreation	151	100.0	.0	.0

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National Summary
Causes of Impairment in Assessed Great Lakes Open Water

Cause of Impairment Group	Square Miles Threatened or Impaired
Polychlorinated Biphenyls (PCBs)	39,183
Dioxins	38,862
Mercury	29,968
Pesticides	29,661
Fish Consumption Advisory	14,087
Organic Enrichment/Oxygen Depletion	13,867
Total Toxics	192
Nuisance Exotic Species	25

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National Summary
Probable Sources of Impairments in Assessed Great Lakes Open Water

Probable Source Group	Square Miles Threatened or Impaired
Atmospheric Deposition	53,270
Legacy/Historical Pollutants	13,991
Urban-Related Runoff/Stormwater	13,867
Agriculture	4,373
Unknown	310
Other	25

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National Causes of Impairment

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National Probable Sources Contributing to Impairments

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National Previously Impaired Waters Now Attaining All Uses

NOTE: Click on the underlined "Number of Waters Attaining" value for a detailed list of those waters now attaining all uses.
Cycle Attaining	Number of Waters Attaining	Number of Causes of Impairment Addressed
2002	23	24
2003	4	7
2004	159	204
2005	107	228
2006	85	101
2007	233	396
2008	339	416
2009	318	487
2010	302	372
2011	168	201
2012	23	24

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Impaired Waters Listed By State

State Name	Number of Waters on 303(d) List
Alabama	209
Alaska	35
American Samoa	44
Arizona	84
Arkansas	224
California	691
Colorado	244
Connecticut	425
Delaware	101
District Of Columbia	36
Florida	2,292
Georgia	215
Guam	47
Hawaii	309
Idaho	915
Illinois	1,057
Indiana	1,836
Iowa	474
Kansas	1,387
Kentucky	1,300
Louisiana	250
Maine	114
Maryland	184
Massachusetts	837
Michigan	2,352
Minnesota	1,144
Mississippi	180
Missouri	245
Montana	604
N. Mariana Islands	24
Nebraska	260
Nevada	181
New Hampshire	1,449
New Jersey	745
New Mexico	196
New York	528
North Carolina	1,270
North Dakota	214
Ohio	267
Oklahoma	743
Oregon	1,397
Pennsylvania	6,957
Puerto Rico	165
Rhode Island	162
South Carolina	961
South Dakota	159
Tennessee	1,028
Texas	651
Utah	118
Vermont	126
Virgin Islands	87
Virginia	1,523
Washington	2,419
West Virginia	1,097
Wisconsin	593
Wyoming	111

Total: 41,266 impaired waters

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National Cumulative TMDLs by Pollutant

This chart includes TMDLs since October 1, 1995.

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
Pathogens	10,164	10,430
Metals (other than Mercury)	8,034	8,211
Mercury	6,973	7,005
Nutrients	5,184	6,194
Sediment	3,685	4,284
Temperature	1,988	1,997
Organic Enrichment/Oxygen Depletion	1,942	2,050
pH/Acidity/Caustic Conditions	1,801	1,841
Salinity/Total Dissolved Solids/Chlorides/Sulfates	1,564	1,619
Turbidity	1,308	1,523
Ammonia	1,084	1,147
Pesticides	1,051	1,148
Polychlorinated Biphenyls (PCBs)	425	446
Chlorine	335	341
Other Cause	217	238
Toxic Inorganics	194	194
Toxic Organics	135	136
Cause Unknown - Impaired Biota	133	137
Total Toxics	102	110
Habitat Alterations	83	84
Algal Growth	69	75
Trash	68	72
Dioxins	27	28
Noxious Aquatic Plants	21	22
Radiation	19	22
Oil and Grease	14	14
Cause Unknown	7	7
Fish Consumption Advisory	2	2
Nuisance Exotic Species	2	2

Total: 46,631 TMDLs; 49,379 Causes of Impairment Addressed

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Approved TMDLs By State

This chart includes TMDLs since October 1, 1995.

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	282
Alaska	52
American Samoa	2
Arizona	82
Arkansas	250
California	1,212
Colorado	992
Connecticut	143
Delaware	576
District Of Columbia	369
Florida	793
Georgia	1,637
Guam	18
Hawaii	56
Idaho	1,794
Illinois	324
Indiana	959
Iowa	170
Kansas	2,870
Kentucky	234
Louisiana	708
Maine	301
Maryland	812
Massachusetts	485
Michigan	193
Minnesota	1,329
Mississippi	1,427
Missouri	287
Montana	870
Nebraska	92
Nevada	64
New Hampshire	6,005
New Jersey	616
New Mexico	302
New York	659
North Carolina	208
North Dakota	107
Ohio	1,471
Oklahoma	496
Oregon