Recent Additions | Contact Us Search: All EPA This Area

• You are here: EPA Home
• Water
• WATERS
• Water Quality Assessment and TMDL Information
• National Summary of State Information

---

Assessed Waters of United States

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

Description of this table

	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	464,428	5,928,815	6,687	1,287	1,041	1,304,892	75	62
Threatened Waters	6,355	47,330	17			805
Impaired Waters	462,601	11,600,032	11,740	791	4,856	746,163	1,110	56,647
Total Assessed Waters	933,384	17,576,176	18,444	2,078	5,897	2,051,861	1,184	56,709
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	26.4	42.2	21.0	3.5	10.9	1.9	22.8	93.7

Top of page

---

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 933,384 Unassessed 2,599,821 Total Miles 3,533,205

Description of this table Attainment Status Miles Good 464,428 Threatened 6,355 Impaired 462,601 Total Miles Assessed 933,384

Top of page

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.

Description of this table

Designated Use Group		Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Fish, Shellfish, And Wildlife Protection And Propagation	300,584	56.5	.5	43.0
	Recreation	118,095	69.9	1.4	28.7
	Agricultural	117,128	87.3	1.4	11.3
	Public Water Supply	86,013	80.6	1.7	17.7
	Aquatic Life Harvesting	43,794	25.9	2.0	72.1
	Industrial	28,236	66.2	.2	33.6
	Other	14,869	7.4	1.7	90.8
	Exceptional Recreational Or Ecological Significance	12,813	3.6	5.0	91.4
	Aesthetic Value	3,654	69.5	.0	30.5

Top of page

National Summary
Causes of Impairment in Assessed Rivers and Streams

Description of this table

Cause of Impairment Group	Miles Threatened or Impaired
Pathogens	141,491
Sediment	107,397
Nutrients	101,316
Organic Enrichment/Oxygen Depletion	83,352
Habitat Alterations	82,442
Polychlorinated Biphenyls (PCBs)	73,064
Metals (other than Mercury)	64,344
Flow Alteration(s)	56,391
Mercury	46,891
Temperature	46,738
Cause Unknown	35,394
Salinity/Total Dissolved Solids/Chlorides/Sulfates	31,656
Cause Unknown - Impaired Biota	30,954
pH/Acidity/Caustic Conditions	27,746
Turbidity	27,032
Pesticides	16,599
Other Cause	16,420
Ammonia	14,113
Fish Consumption Advisory	9,209
Toxic Inorganics	6,225
Dioxins	6,166
Algal Growth	5,840
Toxic Organics	3,658
Oil and Grease	3,654
Total Toxics	3,208
Nuisance Exotic Species	994
Taste, Color and Odor	942
Radiation	814
Chlorine	663
Cause Unknown - Fish Kills	450
Trash	370
Noxious Aquatic Plants	295
Nuisance Native Species	38
Biotoxins	23

Top of page

National Summary
Probable Sources of Impairments in Assessed Rivers and Streams

Description of this table

Probable Source Group	Miles Threatened or Impaired
Agriculture	103,577
Unknown	77,611
Atmospheric Deposition	64,088
Hydromodification	59,899
Natural/Wildlife	53,423
Unspecified Nonpoint Source	44,338
Municipal Dishcarges/Sewage	37,949
Habitat Alterations (Not Directly Related To Hydromodification)	33,015
Urban-Related Runoff/Stormwater	32,043
Resource Extraction	25,438
Silviculture (Forestry)	19,428
Construction	12,533
Industrial	9,924
Other	8,560
Land Application/Waste Sites/Tanks	8,003
Legacy/Historical Pollutants	4,191
Spills/Dumping	1,698
Recreation And Tourism (Non-Boating)	1,668
Aquaculture	1,055
Groundwater Loadings/Withdrawals	181
Recreational Boating And Marinas	147
Military Bases	42

Top of page

---

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

Description of this table Assessed Status Acres Assessed 17,576,176 Unassessed 24,089,873 Total Acres 41,666,049

Description of this table Attainment Status Acres Good 5,928,815 Threatened 47,330 Impaired 11,600,032 Total Acres Assessed 17,576,176

Top of page

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.

Description of this table

Designated Use Group		Acres Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Fish, Shellfish, And Wildlife Protection And Propagation	3,399,558	29.6	.7	69.7
	Recreation	2,229,040	47.8	3.5	48.7
	Public Water Supply	1,926,021	53.8	2.1	44.1
	Agricultural	1,525,560	68.6	2.5	28.9
	Industrial	1,323,247	64.1	.2	35.7
	Aquatic Life Harvesting	1,199,532	19.4	5.0	75.6
	Exceptional Recreational Or Ecological Significance	732,768	16.1	15.6	68.3
	Other	690,152	4.8	1.4	93.8
	Aesthetic Value	356,026	3.0	.0	97.0

Top of page

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

Description of this table

Cause of Impairment Group	Acres Threatened or Impaired
Mercury	6,363,574
Polychlorinated Biphenyls (PCBs)	2,674,268
Nutrients	2,454,436
Organic Enrichment/Oxygen Depletion	1,948,125
Metals (other than Mercury)	1,175,677
Algal Growth	1,054,028
Turbidity	1,008,887
Sediment	720,243
Nuisance Exotic Species	650,335
Temperature	551,724
pH/Acidity/Caustic Conditions	518,354
Flow Alteration(s)	517,765
Fish Consumption Advisory	485,488
Salinity/Total Dissolved Solids/Chlorides/Sulfates	477,875
Pathogens	445,009
Habitat Alterations	443,640
Pesticides	372,020
Nuisance Native Species	277,458
Taste, Color and Odor	114,086
Dioxins	106,378
Toxic Organics	94,158
Noxious Aquatic Plants	60,101
Other Cause	59,905
Cause Unknown	55,771
Cause Unknown - Impaired Biota	55,010
Ammonia	52,746
Radiation	48,264
Total Toxics	23,610
Toxic Inorganics	7,363
Biotoxins	6,147
Cause Unknown - Fish Kills	4,614
Oil and Grease	3,286
Trash	1,701

Top of page

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

Description of this table

Probable Source Group	Acres Threatened or Impaired
Atmospheric Deposition	3,772,604
Unknown	2,615,322
Agriculture	1,579,540
Natural/Wildlife	1,321,000
Hydromodification	1,240,011
Unspecified Nonpoint Source	815,722
Other	777,527
Legacy/Historical Pollutants	755,219
Urban-Related Runoff/Stormwater	716,406
Municipal Dishcarges/Sewage	642,654
Resource Extraction	509,934
Habitat Alterations (Not Directly Related To Hydromodification)	359,247
Construction	300,827
Silviculture (Forestry)	247,865
Industrial	209,500
Spills/Dumping	176,699
Recreational Boating And Marinas	126,174
Commercial Harbor And Port Activities	109,240
Recreation And Tourism (Non-Boating)	108,069
Groundwater Loadings/Withdrawals	98,009
Land Application/Waste Sites/Tanks	80,284
Aquaculture	4,490
Military Bases	2

Top of page

---

National Summary
Water Quality Attainment in Assessed Bays and Estuaries

Description of this table Assessed Status Square Miles Assessed 18,444 Unassessed 69,347 Total Square Miles 87,791

Description of this table Attainment Status Square Miles Good 6,687 Threatened 17 Impaired 11,740 Total Square Miles Assessed 18,444

Top of page

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.

Description of this table

Designated Use Group		Square Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Fish, Shellfish, And Wildlife Protection And Propagation	3,683	7.5	.5	92.1
	Aquatic Life Harvesting	927	.7	1.8	97.5
	Recreation	889	78.3	.1	21.6
	Industrial	570	74.1	.0	25.9
	Exceptional Recreational Or Ecological Significance	533	.8	.0	99.2
	Other	290	13.4	.0	86.6
	Public Water Supply	182	9.9	.0	90.1
	Agricultural	53	.0	.0	100.0

Top of page

National Summary
Causes of Impairment in Assessed Bays and Estuaries

Description of this table

Cause of Impairment Group	Square Miles Threatened or Impaired
Organic Enrichment/Oxygen Depletion	3,601
Polychlorinated Biphenyls (PCBs)	3,240
Pathogens	3,043
Mercury	2,080
Noxious Aquatic Plants	1,924
Metals (other than Mercury)	1,480
Pesticides	1,380
Toxic Organics	995
Nutrients	819
Other Cause	642
Cause Unknown - Impaired Biota	412
Total Toxics	318
Flow Alteration(s)	299
Habitat Alterations	273
Cause Unknown	273
pH/Acidity/Caustic Conditions	250
Turbidity	239
Algal Growth	216
Sediment	209
Salinity/Total Dissolved Solids/Chlorides/Sulfates	141
Dioxins	121
Nuisance Exotic Species	92
Temperature	39
Ammonia	35
Trash	31
Oil and Grease	13
Toxic Inorganics	6
Taste, Color and Odor	3

Top of page

National Summary
Probable Sources of Impairments in Assessed Bays and Estuaries

Description of this table

Probable Source Group	Square Miles Threatened or Impaired
Municipal Dishcarges/Sewage	4,500
Atmospheric Deposition	4,238
Unknown	3,977
Natural/Wildlife	3,789
Industrial	3,044
Agriculture	2,885
Hydromodification	2,532
Other	2,406
Habitat Alterations (Not Directly Related To Hydromodification)	2,091
Urban-Related Runoff/Stormwater	1,994
Unspecified Nonpoint Source	1,773
Resource Extraction	582
Recreational Boating And Marinas	545
Commercial Harbor And Port Activities	481
Legacy/Historical Pollutants	254
Groundwater Loadings/Withdrawals	158
Land Application/Waste Sites/Tanks	52
Spills/Dumping	26
Construction	16
Recreation And Tourism (Non-Boating)	0
Aquaculture	0
Silviculture (Forestry)	0

Top of page

---

National Summary
Water Quality Attainment in Assessed Coastal Shoreline

Description of this table Assessed Status Miles Assessed 2,078 Unassessed 56,540 Total Miles 58,618

Description of this table Attainment Status Miles Good 1,287 Threatened 0 Impaired 791 Total Miles Assessed 2,078

Top of page

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.

Description of this table

Designated Use Group		Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Fish, Shellfish, And Wildlife Protection And Propagation	1,113	56.7	.0	43.3
	Recreation	711	77.5	.0	22.5
	Other	680	73.9	.0	26.1
	Aquatic Life Harvesting	643	82.4	.0	17.6
	Exceptional Recreational Or Ecological Significance	328	80.1	.0	19.9
	Industrial	303	79.5	.0	20.5
	Agricultural	50	.0	.0	100.0
	Public Water Supply	49	.0	.0	100.0

Top of page

National Summary
Causes of Impairment in Assessed Coastal Shoreline

Description of this table

Cause of Impairment Group	Miles Threatened or Impaired
Mercury	338
Pathogens	277
Metals (other than Mercury)	249
Turbidity	69
Pesticides	67
Other Cause	55
Nutrients	42
Cause Unknown	42
Algal Growth	38
Organic Enrichment/Oxygen Depletion	38
Polychlorinated Biphenyls (PCBs)	34
Ammonia	13
Toxic Organics	13
Oil and Grease	13
pH/Acidity/Caustic Conditions	6
Temperature	3
Cause Unknown - Impaired Biota	0

Top of page

National Summary
Probable Sources of Impairments in Assessed Coastal Shoreline

Description of this table

Probable Source Group	Miles Threatened or Impaired
Unspecified Nonpoint Source	101
Natural/Wildlife	100
Urban-Related Runoff/Stormwater	47
Municipal Dishcarges/Sewage	39
Industrial	37
Other	34
Commercial Harbor And Port Activities	20
Recreation And Tourism (Non-Boating)	20
Agriculture	16
Unknown	13
Spills/Dumping	13
Resource Extraction	12
Construction	3
Land Application/Waste Sites/Tanks	1
Recreational Boating And Marinas	1

Top of page

---

National Summary
Water Quality Attainment in Assessed Ocean and Near Coastal

Description of this table Assessed Status Square Miles Assessed 5,897 Unassessed 48,223 Total Square Miles 54,120

Description of this table Attainment Status Square Miles Good 1,041 Threatened 0 Impaired 4,856 Total Square Miles Assessed 5,897

Top of page

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.

Description of this table

Designated Use Group		Square Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Aquatic Life Harvesting	557	87.4	.0	12.6
	Recreation	491	99.2	.0	.8
	Fish, Shellfish, And Wildlife Protection And Propagation	490	99.9	.0	.1
	Public Water Supply	224	100.0	.0	.0
	Other	100	99.4	.0	.6
	Exceptional Recreational Or Ecological Significance	99	100.0	.0	.0
	Industrial	3	100.0	.0	.0

Top of page

National Summary
Causes of Impairment in Assessed Ocean and Near Coastal

Description of this table

Cause of Impairment Group	Square Miles Threatened or Impaired
Mercury	4,639
Polychlorinated Biphenyls (PCBs)	563
Organic Enrichment/Oxygen Depletion	542
Pesticides	487
Pathogens	84
Dioxins	79
Nuisance Exotic Species	35
Total Toxics	29
Metals (other than Mercury)	15
Toxic Organics	14
Turbidity	13
Habitat Alterations	10
Nutrients	8
pH/Acidity/Caustic Conditions	7
Temperature	1
Ammonia	1

Top of page

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

Description of this table

Probable Source Group	Square Miles Threatened or Impaired
Unknown	283
Atmospheric Deposition	70
Municipal Dishcarges/Sewage	8
Recreational Boating And Marinas	8
Hydromodification	5
Recreation And Tourism (Non-Boating)	4
Unspecified Nonpoint Source	4
Urban-Related Runoff/Stormwater	4
Construction	3
Industrial	3
Spills/Dumping	2
Agriculture	1
Commercial Harbor And Port Activities	1
Natural/Wildlife	0

Top of page

---

National Summary
Water Quality Attainment in Assessed Wetlands

Description of this table Assessed Status Acres Assessed 2,051,861 Unassessed 105,648,139 Total Acres 107,700,000

Description of this table Attainment Status Acres Good 1,304,892 Threatened 805 Impaired 746,163 Total Acres Assessed 2,051,861

Top of page

National Summary
Designated Use Support in Assessed Wetlands*

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

Description of this table

Designated Use Group		Acres Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Fish, Shellfish, And Wildlife Protection And Propagation	981,255	67.2	.1	32.7
	Exceptional Recreational Or Ecological Significance	141,544	8.3	44.6	47.2
	Recreation	108,536	26.9	61.8	11.3
	Aquatic Life Harvesting	90,292	.2	.0	99.8
	Industrial	84,516	25.0	.0	75.0
	Public Water Supply	82,403	19.1	.2	80.7
	Other	66,403	.0	.0	100.0
	Agricultural	32,465	47.9	.6	51.5

Top of page

National Summary
Causes of Impairment in Assessed Wetlands

Description of this table

Cause of Impairment Group	Acres Threatened or Impaired
Organic Enrichment/Oxygen Depletion	469,968
Mercury	225,786
Metals (other than Mercury)	166,952
Habitat Alterations	107,594
Nutrients	69,361
Pathogens	66,452
Flow Alteration(s)	33,054
Toxic Inorganics	21,473
Sediment	13,476
Total Toxics	12,659
Salinity/Total Dissolved Solids/Chlorides/Sulfates	11,363
pH/Acidity/Caustic Conditions	10,043
Temperature	7,680
Nuisance Exotic Species	5,300
Algal Growth	3,821
Turbidity	1,965
Cause Unknown	1,665
Fish Consumption Advisory	1,000
Noxious Aquatic Plants	940
Polychlorinated Biphenyls (PCBs)	707
Cause Unknown - Impaired Biota	678
Trash	458
Other Cause	371
Pesticides	362
Ammonia	140
Toxic Organics	133
Radiation	2

Top of page

National Summary
Probable Sources of Impairments in Assessed Wetlands

Description of this table

Probable Source Group	Acres Threatened or Impaired
Agriculture	383,822
Unknown	210,159
Atmospheric Deposition	200,741
Industrial	195,980
Natural/Wildlife	133,558
Hydromodification	115,704
Resource Extraction	89,353
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
Municipal Dishcarges/Sewage	458
Silviculture (Forestry)	2
Urban-Related Runoff/Stormwater	2

Top of page

---

National Summary
Water Quality Attainment in Assessed Great Lakes Shoreline

Description of this table Assessed Status Miles Assessed 1,184 Unassessed 4,018 Total Miles 5,202

Description of this table Attainment Status Miles Good 75 Threatened 0 Impaired 1,110 Total Miles Assessed 1,184

Top of page

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.

Description of this table

Designated Use Group		Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Fish, Shellfish, And Wildlife Protection And Propagation	285	.0	.0	100.0
	Recreation	63	.0	.0	100.0
	Aquatic Life Harvesting	63	.0	.0	100.0

Top of page

National Summary
Causes of Impairment in Assessed Great Lakes Shoreline

Description of this table

Cause of Impairment Group	Miles Threatened or Impaired
Polychlorinated Biphenyls (PCBs)	819
Pathogens	400
Dioxins	323
Pesticides	323
Nuisance Exotic Species	290
Nutrients	290
Sediment	290
Fish Consumption Advisory	285
Habitat Alterations	170
Organic Enrichment/Oxygen Depletion	120
Mercury	59
Algal Growth	8

Top of page

National Summary
Probable Sources of Impairments in Assessed Great Lakes Shoreline

Description of this table

Probable Source Group	Miles Threatened or Impaired
Legacy/Historical Pollutants	682
Atmospheric Deposition	285
Unknown	134
Municipal Dishcarges/Sewage	27
Unspecified Nonpoint Source	9
Urban-Related Runoff/Stormwater	2
Natural/Wildlife	0

Top of page

---

National Summary
Water Quality Attainment in Assessed Great Lakes Open Water

Description of this table Assessed Status Square Miles Assessed 56,709 Unassessed 3,837 Total Square Miles 60,546

Description of this table Attainment Status Square Miles Good 62 Threatened 0 Impaired 56,647 Total Square Miles Assessed 56,709

Top of page

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.

Description of this table

Designated Use Group		Square Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
						% Threatened
						% Impaired
	Fish, Shellfish, And Wildlife Protection And Propagation	14,300	1.5	.0	98.5
	Aquatic Life Harvesting	152	.0	.0	100.0
	Recreation	151	100.0	.0	.0
	Public Water Supply	151	100.0	.0	.0

Top of page

National Summary
Causes of Impairment in Assessed Great Lakes Open Water

Description of this table

Cause of Impairment Group	Square Miles Threatened or Impaired
Polychlorinated Biphenyls (PCBs)	42,560
Dioxins	41,937
Mercury	31,961
Pesticides	29,944
Fish Consumption Advisory	14,087
Organic Enrichment/Oxygen Depletion	13,867
Total Toxics	192
Nuisance Exotic Species	25
Taste, Color and Odor	3
Nutrients	3

Top of page

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

Description of this table

Probable Source Group	Square Miles Threatened or Impaired
Atmospheric Deposition	56,254
Legacy/Historical Pollutants	15,128
Urban-Related Runoff/Stormwater	13,867
Agriculture	4,373
Unknown	554
Other	25
Municipal Dishcarges/Sewage	3
Unspecified Nonpoint Source	3
Industrial	3

Top of page

---

National Causes of Impairment

Description of this table

NOTE: Click on a cause of impairment (e.g. algal growth) to see the specific state-reported causes that are grouped to make up this category.
Cause of Impairment Group	Size of Assessed Waters with Listed Causes of Impairment
	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)
Algal Growth	5,840	1,054,028	216	38		3,821	8
Ammonia	14,113	52,746	35	13	1	140
Biotoxins	23	6,147
Cause Unknown	35,394	55,771	273	42		1,665
Cause Unknown - Fish Kills	450	4,614
Cause Unknown - Impaired Biota	30,954	55,010	412	0		678
Chlorine	663
Dioxins	6,166	106,378	121		79		323	41,937
Fish Consumption Advisory	9,209	485,488		0		1,000	285	14,087
Flow Alteration(s)	56,391	517,765	299			33,054
Habitat Alterations	82,442	443,640	273		10	107,594	170
Mercury	46,891	6,363,574	2,080	338	4,639	225,786	59	31,961
Metals (other than Mercury)	64,344	1,175,677	1,480	249	15	166,952
Noxious Aquatic Plants	295	60,101	1,924			940
Nuisance Exotic Species	994	650,335	92		35	5,300	290	25
Nuisance Native Species	38	277,458
Nutrients	101,316	2,454,436	819	42	8	69,361	290	3
Oil and Grease	3,654	3,286	13	13
Organic Enrichment/Oxygen Depletion	83,352	1,948,125	3,601	38	542	469,968	120	13,867
Other Cause	16,420	59,905	642	55		371
Pathogens	141,491	445,009	3,043	277	84	66,452	400
Pesticides	16,599	372,020	1,380	67	487	362	323	29,944
pH/Acidity/Caustic Conditions	27,746	518,354	250	6	7	10,043
Polychlorinated Biphenyls (PCBs)	73,064	2,674,268	3,240	34	563	707	819	42,560
Radiation	814	48,264				2
Salinity/Total Dissolved Solids/Chlorides/Sulfates	31,656	477,875	141			11,363
Sediment	107,397	720,243	209			13,476	290
Taste, Color and Odor	942	114,086	3					3
Temperature	46,738	551,724	39	3	1	7,680
Total Toxics	3,208	23,610	318		29	12,659		192
Toxic Inorganics	6,225	7,363	6			21,473
Toxic Organics	3,658	94,158	995	13	14	133
Trash	370	1,701	31			458
Turbidity	27,032	1,008,887	239	69	13	1,965

Top of page

---

National Probable Sources Contributing to Impairments

Description of this table

NOTE: Click on a source of impairment (e.g. agriculture) to see the specific state-reported sources that are grouped to make up this category.
Probable Source Group	Size of Assessed Waters with Probable Sources of Impairments
	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)
Agriculture	103,577	1,579,540	2,885	16	1	383,822		4,373
Aquaculture	1,055	4,490	0
Atmospheric Deposition	64,088	3,772,604	4,238		70	200,741	285	56,254
Commercial Harbor And Port Activities		109,240	481	20	1
Construction	12,533	300,827	16	3	3	13,971
Groundwater Loadings/Withdrawals	181	98,009	158			3,045
Habitat Alterations (Not Directly Related To Hydromodification)	33,015	359,247	2,091			8,017
Hydromodification	59,899	1,240,011	2,532		5	115,704
Industrial	9,924	209,500	3,044	37	3	195,980		3
Land Application/Waste Sites/Tanks	8,003	80,284	52	1		1,634
Legacy/Historical Pollutants	4,191	755,219	254				682	15,128
Military Bases	42	2
Municipal Dishcarges/Sewage	37,949	642,654	4,500	39	8	458	27	3
Natural/Wildlife	53,423	1,321,000	3,789	100	0	133,558	0
Other	8,560	777,527	2,406	34		65,874		25
Recreation And Tourism (Non-Boating)	1,668	108,069	0	20	4	787
Recreational Boating And Marinas	147	126,174	545	1	8
Resource Extraction	25,438	509,934	582	12		89,353
Silviculture (Forestry)	19,428	247,865	0			2
Spills/Dumping	1,698	176,699	26	13	2
Unknown	77,611	2,615,322	3,977	13	283	210,159	134	554
Unspecified Nonpoint Source	44,338	815,722	1,773	101	4	63,901	9	3
Urban-Related Runoff/Stormwater	32,043	716,406	1,994	47	4	2	2	13,867

Top of page

---

National Previously Impaired Waters Now Attaining All Uses

Description of this table

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	6
2004	159	203
2005	106	225
2006	84	98
2007	233	367
2008	331	394
2009	103	221

Top of page

---

Impaired Waters Listed By State

Description of this table

State Name	Number of Waters on 303(d) List
Alabama	200
Alaska	32
American Samoa	42
Arizona	68
Arkansas	224
California	691
Colorado	200
Connecticut	408
Delaware	101
District Of Columbia	27
Florida	827
Georgia	281
Guam	54
Hawaii	311
Idaho	1,056
Illinois	1,058
Indiana	1,836
Iowa	278
Kansas	1,333
Kentucky	1,089
Louisiana	250
Maine	206
Maryland	501
Massachusetts	837
Michigan	2,352
Minnesota	1,144
Mississippi	197
Missouri	0
Montana	677
N. Mariana Islands	71
Nebraska	177
Nevada	129
New Hampshire	5,211
New Jersey	745
New Mexico	187
New York	491
North Carolina	902
North Dakota	247
Ohio	267
Oklahoma	743
Oregon	1,397
Pennsylvania	6,957
Puerto Rico	166
Rhode Island	141
South Carolina	1,060
South Dakota	168
Tennessee	900
Texas	651
Utah	118
Vermont	131
Virgin Islands	77
Virginia	2,534
Washington	2,419
West Virginia	981
Wisconsin	593
Wyoming	106

Total: 43,849 impaired waters

Top of page

---

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
Pathogens	7,653	7,881
Metals (other than Mercury)	6,928	7,064
Mercury	6,793	6,825
Nutrients	4,397	5,268
Sediment	3,372	3,900
Organic Enrichment/Oxygen Depletion	1,800	1,874
pH/Acidity/Caustic Conditions	1,601	1,637
Temperature	1,548	1,555
Salinity/Total Dissolved Solids/Chlorides/Sulfates	1,514	1,555
Ammonia	1,043	1,105
Pesticides	988	1,048
Turbidity	885	1,009
Polychlorinated Biphenyls (PCBs)	357	371
Chlorine	336	341
Other Cause	208	225
Toxic Inorganics	189	189
Cause Unknown - Impaired Biota	168	172
Toxic Organics	125	125
Total Toxics	94	102
Habitat Alterations	83	84
Algal Growth	65	69
Trash	65	68
Dioxins	24	25
Noxious Aquatic Plants	21	22
Radiation	21	22
Oil and Grease	12	13
Cause Unknown	5	5
Fish Consumption Advisory	2	2
Nuisance Exotic Species	2	2

Total: 40,299 TMDLs; 42,558 Causes of Impairment Addressed

Top of page

---

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	265
Alaska	44
American Samoa	2
Arizona	69
Arkansas	232
California	979
Colorado	955
Connecticut	109
Delaware	558
District Of Columbia	360
Florida	657
Georgia	1,554
Guam	1
Hawaii	49
Idaho	1,611
Illinois	302
Indiana	768
Iowa	136
Kansas	2,727
Kentucky	123
Louisiana	665
Maine	292
Maryland	607
Massachusetts	426
Michigan	160
Minnesota	1,166
Mississippi	1,310
Missouri	137
Montana	607
Nebraska	91
Nevada	58
New Hampshire	5,510
New Jersey	598
New Mexico	224
New York	638
North Carolina	145
North Dakota	69
Ohio	1,147
Oklahoma	223
Oregon	1,035
Pennsylvania	6,133
Puerto Rico	53
Rhode Island	104
South Carolina	425
South Dakota	269
Tennessee	1,039
Texas	154
Utah	301
Vermont	94
Virgin Islands	29
Virginia	970
Washington	1,120
West Virginia	2,561
Wisconsin	96
Wyoming	342

Total: 40,299 TMDLs

Top of page

---

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	122	123
1997	338	352
1998	403	409
1999	334	380
2000	1,560	1,584
2001	2,571	2,607
2002	2,745	2,820
2003	2,970	3,247
2004	3,377	3,642
2005	4,245	4,563
2006	4,202	4,554
2007	4,321	4,652
2008	9,197	9,477
2009	3,892	4,112
2010	22	36

Total: 40,299 TMDLs; 42,558 Causes of Impairment Addressed

Top of page

---

Status of Available Data Used in This Report

Description of this table

State Name	Assessed Waters Report Year	Impaired Waters Report Year
Alabama	2008	2008
Alaska	2008	2008
American Samoa	2008	2008
Arizona	2008	2004
Arkansas	2008	2008
California	2004	2006
Colorado	2008	2008
Connecticut	2008	2008
Delaware	2006	2006
District Of Columbia	2008	2008
Florida	2002	2002
Georgia	2008	2008
Guam	2008	2008
Hawaii	2006	2006
Idaho	2008	2008
Illinois	2006	2006
Indiana	2008	2008
Iowa	2008	2006
Kansas	2008	2008
Kentucky	2008	2008
Louisiana	2008	2006
Maine	2008	2008
Maryland	2002	2006
Massachusetts	2006	2006
Michigan	2008	2008
Minnesota	2008	2008
Mississippi	2008	2008
Missouri	2008	2008
Montana	2006	2006
N. Mariana Islands	2008	2008
Nebraska	2008	2008
Nevada	2006	2004
New Hampshire	2006	2006
New Jersey	2008	2008
New Mexico	2008	2008
New York	2008	2008
North Carolina	2006	2006
North Dakota	2008	2008
Ohio	2008	2008
Oklahoma	2008	2008
Oregon	2006	2006
Pennsylvania	2006	2004
Puerto Rico	2008	2008
Rhode Island	2008	2008
South Carolina	2008	2008
South Dakota	2008	2008
Tennessee	2008	2008
Texas	2008	2008
Utah	2006	2006
Vermont	2008	2008
Virgin Islands	2008	2008
Virginia	2008	2008
Washington	2008	2008
West Virginia	2008	2008
Wisconsin	2006	2006
Wyoming	2008	2008

TMDL Document Search

Top of page

• EPA Home
• Privacy and Security Notice
• Contact Us