Cleanest/Best States

National Average

Dirtiest/Worst States

0%					50%					100%

Percentage of Surface Waters with Impaired or Threatened Uses (state + EPA data):

Number of Impaired Waterbodies (as reported by the state):

NOTE: Data limitations affect the accuracy of these rankings.

Rank counties in ILLINOIS or in the U.S. by assessed use impairments.
Rank watersheds in ILLINOIS by assessed use impairments
Rank states by assessed use impairments, impairments due to specific causes, or impairments due to specific sources

ILLINOIS contains a portion of 49 watersheds.

Percentage of Surface Waters with Reported Problems (state + EPA data): 7%

Number of Waterbodies with Reported Problems (as reported by the state): 738

Beneficial Use Most Frequently Impaired	Percent of All Impairments
Overall Use	100%
Primary Contact Recreation (Swimming)	80%
Aquatic Life Support	80%
Fish Consumption	77%
SecondaryContact Recreation (Boating)	30%
Drinking Water Supply	2%

Beneficial uses not reported for 100% of waterbodies.

Priority for Regulation	Number of Waterbodies
Targeted	25
High	347
Medium	208
Low	157
Not Assessed for TMDL Priority	1
Not Reported to US EPA for TMDL Priority	0

Rivers, Streams, and Creeks
Number of impaired waterbodies: 537 (cause not reported for 0%)
Percent of Rivers, Streams and Creeks in ILLINOIS assessed by agencies for 1997-98 reporting period: 33%

	Percent Waterbodies Affected
Nutrients	82%
Sediments	78%
Other Habitat Alterations	31%
Metals	28%
Low Dissolved Oxygen/Organic Enrichment	26%
More...

NOTE: Possible inconsistencies between data on (a) impaired waterbodies and (b) percentage of waterbodies assessed.

Rivers, Streams, and Creeks
Number of impaired waterbodies: 537 (cause not reported for 0%)
Percent of Rivers, Streams and Creeks in ILLINOIS assessed by agencies for 1997-98 reporting period: 33%

	Percent Waterbodies Affected
Agriculture	73%
Hydromodification/Habitat Modification	55%
Municipal Point Sources	42%
Urban Runoff/Storm Sewers	26%
Resource Extraction	18%
More...

NOTE: Possible inconsistencies between data on (a) impaired waterbodies and (b) percentage of waterbodies assessed.