Recent Additions | Contact Us Search: All EPA This Area

• You are here: EPA Home
• Water
• WATERS
• Water Quality Assessment and TMDL Information
• District Of Columbia Water Quality Assessment Report

---

District Of Columbia Assessment Summary for Reporting Year 2006

Description of this table

	Size of Water
	Rivers and Streams (Miles)	Lakes, Reservoirs, and Ponds (Acres)	Bays and Estuaries (Square Miles)
Good Waters
Previously impaired waters       now attaining all uses
Threatened Waters
TMDL completed
TMDL alternative
Non-pollutant impairment
TMDL needed
Impaired Waters	38.4	238.4	5.9
TMDL completed	19.8	102.7
TMDL alternative
Non-pollutant impairment
TMDL needed	18.6	135.7	5.9
New TMDLs completed	.0	.0	.0
Remaining TMDLs needed	18.6	135.7	5.9
Total Assessed Waters	38.4	238.4	5.9
Total Waters	39.0	238.4	6.0
Percent of Waters Assessed	98.5	100.0	98.8

Top of page

---

Summary of Water Quality Assessments for Each Waterbody Type
for Reporting Year 2006

District Of Columbia Assessed Waters
Summary of Water Quality Attainment for Rivers and Streams
Reporting Year 2006

Description of this table Assessed Status Miles Assessed 38.4 Unassessed .6 Total Miles 39.0

Description of this table Attainment Status Miles Good .0 Threatened .0 Impaired 38.4 Total Miles Assessed 38.4

Description of this table TMDL Development Status Miles All TMDLs completed 19.8 TMDL alternative .0 Non-pollutant impairment .0 TMDL needed 18.6 Total Threatened and Impaired 38.4

Top of page

District Of Columbia Assessed Waters
Designated Use Support for Rivers and Streams
Reporting Year 2006*

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

Description of this table

Designated Use	Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
					% Threatened
					% Impaired
Navigation	9.5	100.0	.0	.0
Primary Contact Recreation	38.4	.0	.0	100.0
Protection And Propagation Of Fish, Shellfish And Wildlife	34.9	.0	.0	100.0
Protection Of Human Health Related To Consumption Of Fish And Shellfish	36.4	.0	.0	100.0
Secondary Contact Recreation And Aesthetic Enjoyment	38.4	.0	.0	100.0

Top of page

District Of Columbia Causes of Impairment
for Threatened and Impaired Rivers and Streams
Reporting Year 2006

Description of this table

Cause of Impairment	Cause of Impairment Group	Miles Threatened or Impaired
Fecal Coliform	Pathogens	37.6
Combination Benthic/Fishes Bioassessments	Cause Unknown - Impaired Biota	34.1
Particle Distribution (Embeddedness)	Sediment	28.0
Other Flow Regime Alterations	Flow Alteration(s)	18.7
Debris/Floatables/Trash	Trash	16.5
Combined Biota/Habitat Bioassessments (Streams)	Cause Unknown - Impaired Biota	13.0
Benthic Macroinvertebrates Bioassessments	Cause Unknown - Impaired Biota	6.2
Alterations in Wetland Habitats	Habitat Alterations	6.2
Fishes Bioassessments (Streams)	Cause Unknown - Impaired Biota	6.2
Alteration in Stream-Side or Littoral Vegetative Covers	Habitat Alterations	5.1
Total Suspended Solids (TSS)	Turbidity	3.7
Oil and Grease	Oil and Grease	1.7
Habitat Assessment (Streams)	Cause Unknown - Impaired Biota	1.0
Physical Substrate Habitat Alterations	Habitat Alterations	.7

Top of page

District Of Columbia Probable Sources of Impairments
for Threatened and Impaired Rivers and Streams
Reporting Year 2006

Description of this table

Probable Source	Probable Source Group	Miles Threatened or Impaired
Residential Districts	Urban-Related Runoff/Stormwater	30.9
Discharges From Municipal Separate Storm Sewer Systems (Ms4)	Urban-Related Runoff/Stormwater	23.5
Wet Weather Discharges (Non-Point Source)	Urban-Related Runoff/Stormwater	18.7
Wet Weather Discharges (Point Source And Combination Of Stormwater, Sso Or Cso)	Municipal Dishcarges/Sewage	18.7
Yard Maintenance	Urban-Related Runoff/Stormwater	15.6
Hydrostructure Impacts On Fish Passage	Hydromodification	15.4
Source Unknown	Unknown	15.1
Impacts From Hydrostructure Flow Regulation/Modification	Hydromodification	14.7
Illegal Dumps Or Other Inappropriate Waste Disposal	Spills/Dumping	11.4
Illegal Dumping	Spills/Dumping	9.9
Combined Sewer Overflows	Municipal Dishcarges/Sewage	9.5
Post-Development Erosion And Sedimentation	Hydromodification	8.5
Municipal (Urbanized High Density Area)	Urban-Related Runoff/Stormwater	5.8
Channelization	Hydromodification	5.6
Site Clearance (Land Development Or Redevelopment)	Construction	5.3
Cercla Npl (Superfund) Sites	Legacy/Historical Pollutants	1.6
Loss Of Riparian Habitat	Habitat Alterations (Not Directly Related To Hydromodification)	1.2
Municipal Point Source Discharges	Municipal Dishcarges/Sewage	.9
Above Ground Storage Tank Leaks (Tank Farms)	Spills/Dumping	.9
Landfills	Land Application/Waste Sites/Tanks	.6

Top of page

---

District Of Columbia Assessed Waters
Summary of Water Quality Attainment for Lakes, Reservoirs, and Ponds
Reporting Year 2006

Description of this table Assessed Status Acres Assessed 238.4 Unassessed .0 Total Acres 238.4

Description of this table Attainment Status Acres Good .0 Threatened .0 Impaired 238.4 Total Acres Assessed 238.4

Description of this table TMDL Development Status Acres All TMDLs completed 102.7 TMDL alternative .0 Non-pollutant impairment .0 TMDL needed 135.7 Total Threatened and Impaired 238.4

Top of page

District Of Columbia Assessed Waters
Designated Use Support for Lakes, Reservoirs, and Ponds
Reporting Year 2006*

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

Description of this table

Designated Use	Acres Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
					% Threatened
					% Impaired
Navigation	238.4	100.0	.0	.0
Primary Contact Recreation	238.4	.0	.0	100.0
Protection And Propagation Of Fish, Shellfish And Wildlife	238.4	11.5	.0	88.5
Protection Of Human Health Related To Consumption Of Fish And Shellfish	238.4	.0	.0	100.0
Secondary Contact Recreation And Aesthetic Enjoyment	238.4	45.5	.0	54.5

Top of page

District Of Columbia Causes of Impairment
for Threatened and Impaired Lakes, Reservoirs, and Ponds
Reporting Year 2006

Description of this table

Cause of Impairment	Cause of Impairment Group	Acres Threatened or Impaired
Fecal Coliform	Pathogens	238.4
Dissolved Oxygen	Organic Enrichment/Oxygen Depletion	102.7
Solids (Suspended/Bedload)	Sediment	102.7
Oil and Grease	Oil and Grease	102.7
Sedimentation/Siltation	Sediment	102.7

Top of page

District Of Columbia Probable Sources of Impairments
for Threatened and Impaired Lakes, Reservoirs, and Ponds
Reporting Year 2006

Description of this table

Probable Source	Probable Source Group	Acres Threatened or Impaired
Discharges From Municipal Separate Storm Sewer Systems (Ms4)	Urban-Related Runoff/Stormwater	238.4
Combined Sewer Overflows	Municipal Dishcarges/Sewage	102.7

Top of page

---

District Of Columbia Assessed Waters
Summary of Water Quality Attainment for Bays and Estuaries
Reporting Year 2006

Description of this table Assessed Status Square Miles Assessed 5.9 Unassessed .1 Total Square Miles 6.0

Description of this table Attainment Status Square Miles Good .0 Threatened .0 Impaired 5.9 Total Square Miles Assessed 5.9

Description of this table TMDL Development Status Square Miles All TMDLs completed .0 TMDL alternative .0 Non-pollutant impairment .0 TMDL needed 5.9 Total Threatened and Impaired 5.9

Top of page

District Of Columbia Assessed Waters
Designated Use Support for Bays and Estuaries
Reporting Year 2006*

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

Description of this table

Designated Use	Square Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
					% Threatened
					% Impaired
Navigation	5.9	100.0	.0	.0
Primary Contact Recreation	5.9	.0	.0	100.0
Protection And Propagation Of Fish, Shellfish And Wildlife	5.9	81.5	.0	18.5
Protection Of Human Health Related To Consumption Of Fish And Shellfish	5.9	.0	.0	100.0
Secondary Contact Recreation And Aesthetic Enjoyment	5.9	63.2	.0	36.8

Top of page

District Of Columbia Causes of Impairment
for Threatened and Impaired Bays and Estuaries
Reporting Year 2006

Description of this table

Cause of Impairment	Cause of Impairment Group	Square Miles Threatened or Impaired
Fecal Coliform	Pathogens	5.9
Oil and Grease	Oil and Grease	.8
Solids (Suspended/Bedload)	Sediment	.3
Sedimentation/Siltation	Sediment	.3
Dissolved Oxygen	Organic Enrichment/Oxygen Depletion	.3
Biochemical Oxygen Demand (BOD)	Organic Enrichment/Oxygen Depletion	.3

Top of page

District Of Columbia Probable Sources of Impairments
for Threatened and Impaired Bays and Estuaries
Reporting Year 2006

Description of this table

Probable Source	Probable Source Group	Square Miles Threatened or Impaired
Combined Sewer Overflows	Municipal Dishcarges/Sewage	5.6
Discharges From Municipal Separate Storm Sewer Systems (Ms4)	Urban-Related Runoff/Stormwater	5.2
Municipal Point Source Discharges	Municipal Dishcarges/Sewage	4.4
Source Unknown	Unknown	1.4
Highway/Road/Bridge Runoff (Non-Construction Related)	Urban-Related Runoff/Stormwater	.8
Petroleum/Natural Gas Production Activities (Permitted)	Industrial	.8
Municipal (Urbanized High Density Area)	Urban-Related Runoff/Stormwater	.4
Dredging (E.G., For Navigation Channels)	Hydromodification	.3

Top of page

---

District Of Columbia Causes of Impairment for Reporting Year 2006

Description of this table

NOTE: Click on the underlined Cause of Impairment Group to see a list of specific state causes of impairment making up the Cause of Impairment Group.
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)
Cause Unknown - Impaired Biota	34.1
Flow Alteration(s)	18.7
Habitat Alterations	10.6
Oil and Grease	1.7	102.7	.8
Organic Enrichment/Oxygen Depletion		102.7	.3
Pathogens	37.6	238.4	5.9
Sediment	28.0	102.7	.3
Trash	16.5
Turbidity	3.7

Top of page

---

District Of Columbia Probable Sources Contributing to Impairments
for Reporting Year 2006

Description of this table

NOTE: Click on the underlined Probable Source Group to see a list of specific state Probable Sources making up the Probable Source Group.
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)
Construction	5.3
Habitat Alterations (Not Directly Related To Hydromodification)	1.2
Hydromodification	27.9		.3
Industrial			.8
Land Application/Waste Sites/Tanks	.6
Legacy/Historical Pollutants	1.6
Municipal Dishcarges/Sewage	19.6	102.7	5.6
Spills/Dumping	11.4
Unknown	15.1		1.4
Urban-Related Runoff/Stormwater	35.2	238.4	5.6

Top of page

---

District Of Columbia TMDL Alternatives by Cause of Impairment 2006

No TMDL Alternatives reported.

Top of page

---

District Of Columbia Previously Impaired Waters Now Attaining All Uses

No previously impaired waters reported as attaining all uses.

Top of page

---

District Of Columbia 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
Cause Unknown - Impaired Biota	30
Pathogens	24
Sediment	9
Other Cause	8
Habitat Alterations	6
Flow Alteration(s)	5
Oil and Grease	3
Organic Enrichment/Oxygen Depletion	2
Turbidity	1

Total: 88 Causes of Impairment

Top of page

---

District Of Columbia Cumulative TMDLs by Pollutant

This chart includes TMDLs since October 1, 1995.

Description of this table

NOTE: Click on the underlined "Pollutant" value to see associated listed waters for which a TMDL was developed. Click on the underlined "Number of TMDLs" value to see a listing of those TMDLs for the pollutant.
Pollutant	Number of TMDLs	Number of Causes of Impairment Addressed
DDT	25	25
Dieldrin	25	25
Heptachlor Epoxide	25	25
PAH1 - 2 & 3 Ring Polycyclic Aromatic Hydrocarbons	25	25
PAH2 - 4 Ring Polycyclic Aromatic Hydrocarbons	25	25
PAH3 - 5 && Ring Polycyclic Aromatic Hydrocarbons	25	25
Chlordane	24	24
DDE	24	24
DDD	23	23
Fecal Coliform	22	22
Polychlorinated Biphenyls (PCBs)	19	19
Copper	16	16
Lead	16	16
Zinc	16	16
Arsenic	14	14
Pathogens	9	9
Biochemical Oxygen Demand (BOD)	6	6
Suspended Solids	5	5
Oil and Grease	4	4
Mercury	2	2
Nitrogen	2	2
Phosphorus	2	2
Suspended Sediment	2	2
Toxics	2	2
pH	2	2

Total: 360 TMDLs; 360 Causes of Impairment Addressed

Top of page

District Of Columbia 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
1999	1	1
2002	7	7
2003	129	129
2004	150	150
2005	60	60
2007	2	2
2008	11	11

Total: 360 TMDLs; 360 Causes of Impairment Addressed

Top of page

---

TMDL Document Search

Top of page

• EPA Home
• Privacy and Security Notice
• Contact Us