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Delaware Assessment Summary for Reporting Year 2006

	Size of Water
	Rivers and Streams (Miles)	Lakes, Reservoirs, and Ponds (Acres)	Bays and Estuaries (Square Miles)	Coastal Shoreline (Miles)
Good Waters	8.8	90.0		25.0
Previously impaired waters       now attaining all uses
Threatened Waters
TMDL completed
TMDL alternative
Non-pollutant impairment
TMDL needed
Impaired Waters	2,497.3	2,863.9	29.5
TMDL completed	476.3	1,427.5	3.0
TMDL alternative
Non-pollutant impairment
TMDL needed	2,020.9	1,436.4	26.5
New TMDLs completed	.0	.0	.0	.0
Remaining TMDLs needed	2,020.9	1,436.4	26.5
Total Assessed Waters	2,506.1	2,953.9	29.5	25.0
Total Waters	2,509.0	2,954.0	448.5	25.0
Percent of Waters Assessed	99.9	100.0	6.6	100.0

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

Delaware Assessed Waters
Summary of Water Quality Attainment for Rivers and Streams
Reporting Year 2006

Description of this table Assessed Status Miles Assessed 2,506.1 Unassessed 2.9 Total Miles 2,509.0

Description of this table Attainment Status Miles Good 8.8 Threatened .0 Impaired 2,497.3 Total Miles Assessed 2,506.1

Description of this table TMDL Development Status Miles All TMDLs completed 476.3 TMDL alternative .0 Non-pollutant impairment .0 TMDL needed 2,020.9 Total Threatened and Impaired 2,497.3

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Delaware 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.

Designated Use	Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
					% Threatened
					% Impaired
Agricultural Water Supply	1,928.1	100.0	.0	.0
Cold Water Fish	66.6	80.8	.0	19.2
Fish, Aquatic Life, And Wildlife	2,478.2	2.9	.0	97.1
Harvestable Shellfish Waters	5.2	.0	.0	100.0
Industrial Water Supply	2,448.7	100.0	.0	.0
Primary Contact Recreation	2,479.4	11.6	.0	88.4
Public Water Supply	204.5	97.1	.0	2.9
Secondary Contact Recreation	2,475.0	100.0	.0	.0
Waters Of Exceptional Recreational Or Ecological Significance	867.3	21.9	.0	78.1

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Delaware Causes of Impairment
for Threatened and Impaired Rivers and Streams
Reporting Year 2006

Cause of Impairment	Cause of Impairment Group	Miles Threatened or Impaired
Phosphorus, Total	Nutrients	2,191.3
Nitrogen, Total	Nutrients	2,079.6
Enterococcus Bacteria	Pathogens	1,898.3
Habitat Assessment (Streams)	Cause Unknown - Impaired Biota	268.9
Nitrate/Nitrite (Nitrite + Nitrate as N)	Nutrients	185.8
Polychlorinated Biphenyls (PCBs)	Polychlorinated Biphenyls (PCBs)	114.6
Total Kjehldahl Nitrogen (TKN)	Nutrients	91.5
Organic Enrichment (Sewage) Biological Indicators	Organic Enrichment/Oxygen Depletion	75.6
Dioxin (Including 2,3,7,8-TCDD)	Dioxins	72.6
Dieldrin	Pesticides	37.8
Chlordane	Pesticides	31.8
Mercury	Mercury	24.1
Ammonia, Un-ionized	Ammonia	21.3
DDT in Fish Tissue	Pesticides	17.0
DDT	Pesticides	12.8
Zinc	Metals (other than Mercury)	12.8
Temperature, Water	Temperature	9.4
Solids (Suspended/Bedload)	Sediment	9.4
Cause Unknown	Cause Unknown	6.9

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Delaware Probable Sources of Impairments
for Threatened and Impaired Rivers and Streams
Reporting Year 2006

Probable Source	Probable Source Group	Miles Threatened or Impaired
Agriculture	Agriculture	847.9
Natural Sources	Natural/Wildlife	423.5
Source Unknown	Unknown	247.5
On-Site Treatment Systems (Septic Systems And Similar Decencentralized Systems)	Municipal Dishcarges/Sewage	172.1
Municipal Point Source Discharges	Municipal Dishcarges/Sewage	118.4
Industrial Point Source Discharge	Industrial	105.0
Rcra Hazardous Waste Sites	Industrial	10.0
Combined Sewer Overflows	Municipal Dishcarges/Sewage	9.3
Site Clearance (Land Development Or Redevelopment)	Construction	8.2
Construction Stormwater Discharge (Permitted)	Construction	8.2
Landfills	Land Application/Waste Sites/Tanks	5.2

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

Description of this table Assessed Status Acres Assessed 2,953.9 Unassessed .1 Total Acres 2,954.0

Description of this table Attainment Status Acres Good 90.0 Threatened .0 Impaired 2,863.9 Total Acres Assessed 2,953.9

Description of this table TMDL Development Status Acres All TMDLs completed 1,427.5 TMDL alternative .0 Non-pollutant impairment .0 TMDL needed 1,436.4 Total Threatened and Impaired 2,863.9

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Delaware 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.

Designated Use	Acres Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
					% Threatened
					% Impaired
Agricultural Water Supply	2,764.6	100.0	.0	.0
Fish, Aquatic Life, And Wildlife	2,953.9	11.3	.0	88.7
Industrial Water Supply	2,953.9	100.0	.0	.0
Primary Contact Recreation	2,953.9	55.6	.0	44.4
Public Water Supply	295.6	100.0	.0	.0
Secondary Contact Recreation	2,942.0	82.4	.0	17.6
Waters Of Exceptional Recreational Or Ecological Significance	757.8	33.9	.0	66.1

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Delaware Causes of Impairment
for Threatened and Impaired Lakes, Reservoirs, and Ponds
Reporting Year 2006

Cause of Impairment	Cause of Impairment Group	Acres Threatened or Impaired
Phosphorus, Total	Nutrients	2,512.5
Nitrogen, Total	Nutrients	2,203.9
Enterococcus Bacteria	Pathogens	983.6
Nitrate/Nitrite (Nitrite + Nitrate as N)	Nutrients	390.4
Polychlorinated Biphenyls (PCBs)	Polychlorinated Biphenyls (PCBs)	210.5
Mercury	Mercury	183.4
Dioxin (Including 2,3,7,8-TCDD)	Dioxins	157.8
Total Kjehldahl Nitrogen (TKN)	Nutrients	150.0
DDT in Fish Tissue	Pesticides	27.1

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Delaware Probable Sources of Impairments
for Threatened and Impaired Lakes, Reservoirs, and Ponds
Reporting Year 2006

Probable Source	Probable Source Group	Acres Threatened or Impaired
Agriculture	Agriculture	403.6
Source Unknown	Unknown	253.4
Natural Sources	Natural/Wildlife	237.4

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Delaware Assessed Waters
Summary of Water Quality Attainment for Bays and Estuaries
Reporting Year 2006

Description of this table Assessed Status Square Miles Assessed 29.5 Unassessed 419.0 Total Square Miles 448.5

Description of this table Attainment Status Square Miles Good .0 Threatened .0 Impaired 29.5 Total Square Miles Assessed 29.5

Description of this table TMDL Development Status Square Miles All TMDLs completed 3.0 TMDL alternative .0 Non-pollutant impairment .0 TMDL needed 26.5 Total Threatened and Impaired 29.5

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Delaware 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.

Designated Use	Square Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
					% Threatened
					% Impaired
Fish, Aquatic Life, And Wildlife	29.0	.0	.0	100.0
Harvestable Shellfish Waters	14.5	4.1	.0	95.9
Industrial Water Supply	29.0	100.0	.0	.0
Primary Contact Recreation	29.5	50.8	.0	49.2
Secondary Contact Recreation	29.0	100.0	.0	.0
Waters Of Exceptional Recreational Or Ecological Significance	29.5	10.2	.0	89.8

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Delaware Causes of Impairment
for Threatened and Impaired Bays and Estuaries
Reporting Year 2006

Cause of Impairment	Cause of Impairment Group	Square Miles Threatened or Impaired
Organic Enrichment (Sewage) Biological Indicators	Organic Enrichment/Oxygen Depletion	28.0
Total Kjehldahl Nitrogen (TKN)	Nutrients	28.0
Nitrate/Nitrite (Nitrite + Nitrate as N)	Nutrients	28.0
Enterococcus Bacteria	Pathogens	26.5
Phosphorus, Total	Nutrients	26.0
Solids (Suspended/Bedload)	Sediment	12.0
Nitrogen, Total	Nutrients	1.0
Temperature, Water	Temperature	1.0

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Delaware Probable Sources of Impairments
for Threatened and Impaired Bays and Estuaries
Reporting Year 2006

Probable Source	Probable Source Group	Square Miles Threatened or Impaired
Municipal Point Source Discharges	Municipal Dishcarges/Sewage	25.0
On-Site Treatment Systems (Septic Systems And Similar Decencentralized Systems)	Municipal Dishcarges/Sewage	13.0
Agriculture	Agriculture	12.0
Natural Sources	Natural/Wildlife	3.0
Source Unknown	Unknown	3.0

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Delaware Assessed Waters
Summary of Water Quality Attainment for Coastal Shoreline
Reporting Year 2006

Description of this table Assessed Status Miles Assessed 25.0 Unassessed .0 Total Miles 25.0

Description of this table Attainment Status Miles Good 25.0 Threatened .0 Impaired .0 Total Miles Assessed 25.0

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

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Delaware Assessed Waters
Designated Use Support for Coastal Shoreline
Reporting Year 2006*

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

Designated Use	Miles Assessed	Percent Good	Percent Threatened	Percent Impaired	% Good
					% Threatened
					% Impaired
Fish, Aquatic Life, And Wildlife	25.0	100.0	.0	.0
Industrial Water Supply	25.0	100.0	.0	.0
Primary Contact Recreation	25.0	100.0	.0	.0
Secondary Contact Recreation	25.0	100.0	.0	.0

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Delaware Causes of Impairment
for Threatened and Impaired Coastal Shoreline
Reporting Year 2006

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Delaware Probable Sources of Impairments
for Threatened and Impaired Coastal Shoreline
Reporting Year 2006

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Delaware Causes of Impairment for Reporting Year 2006

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Delaware Probable Sources Contributing to Impairments
for Reporting Year 2006

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Delaware TMDL Alternatives by Cause of Impairment 2006

NOTE: Click on the underlined "Number of TMDL Alternatives by Cause of Impairment " value to see a listing of those Causes of Impairment.
Cause of Impairment	Number of TMDL Alternatives	Rivers and Streams (Miles)
Nitrate/Nitrite (Nitrite + Nitrate as N)	1	11
Organic Enrichment (Sewage) Biological Indicators	1	11
Phosphorus, Total	1	11
Total Kjehldahl Nitrogen (TKN)	1	11

Total: 4 TMDL Alternatives

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Delaware Previously Impaired Waters Now Attaining All Uses

No previously impaired waters reported as attaining all uses.

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Delaware Causes of Impairment for 303(d) Listed Waters

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
Nutrients	84
Pathogens	65
Cause Unknown - Impaired Biota	19
Polychlorinated Biphenyls (PCBs)	14
Pesticides	11
Dioxins	7
Mercury	3
Organic Enrichment/Oxygen Depletion	1
Cause Unknown	1
Turbidity	1

Total: 206 Causes of Impairment

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Delaware Cumulative TMDLs by Pollutant

This chart includes TMDLs since October 1, 1995.

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
Phosphorus	164	172
Bacteria	149	149
Nitrogen	114	114
Dissolved Oxygen	80	80
Ammonia	17	17
Biochemical Oxygen Demand (BOD)	15	15
Carbonaceous Bod	5	5
Nutrients	3	3
Polychlorinated Biphenyls (PCBs)	3	3
Habitat	2	2
Temperature	2	2
Zinc	2	2
Escherichia Coli (E. Coli)	1	1
Phosphates	1	1

Total: 558 TMDLs; 566 Causes of Impairment Addressed

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Delaware Cumulative Number of TMDLs

EPA Fiscal Year starts October 1 and ends September 30.

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
1998	3	3
1999	10	10
2000	2	2
2001	72	72
2003	29	37
2004	14	14
2005	57	57
2006	100	100
2007	271	271

Total: 558 TMDLs; 566 Causes of Impairment Addressed

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TMDL Document Search

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