POLLUTION LOCATOR| Water | State Clean Water Act Status Report

Clean Water Act Status: MONTANA
 
 
  • Clean Water Act Comparative Ranking
    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 MONTANA or in the U.S. by assessed use impairments.
    Rank watersheds in MONTANA by assessed use impairments
    Rank states by assessed use impairments, impairments due to specific causes, or impairments due to specific sources

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  • 1998 Clean Water Act Status
    MONTANA contains a portion of 98 watersheds.
    Percentage of Surface Waters with Reported Problems (state + EPA data): 11%
    Number of Waterbodies with Reported Problems (as reported by the state): 869
    Beneficial Use Most Frequently Impaired Percent of All Impairments
    Fish Consumption 79%
    Aquatic Life Support 78%
    Drinking Water Supply 26%
    Primary Contact Recreation (Swimming) 25%
    Agriculture 11%
    Industrial 2%
    Cultural 1%
    Overall Use 0%
    Beneficial uses not reported for 100% of waterbodies.


    Priority for Regulation     Number of Waterbodies
    Targeted 16
    High 9
    Medium 21
    Low 817
    Not Assessed for TMDL Priority 3
    Not Reported to US EPA for TMDL Priority 3
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  • Leading Pollutants/Stressors of Surface Waters
    Rivers, Streams, and Creeks
    Number of impaired waterbodies: 820 (cause not reported for 0%)
    Percent of Rivers, Streams and Creeks in MONTANA assessed by agencies for 1997-98 reporting period: 10%
      Percent Waterbodies Affected
    Sediments 73%
    Other Habitat Alterations 56%
    Flow Alterations 45%
    Metals 18%
    Nutrients 17%
    More...

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


    Lakes, Reservoirs, and Ponds
    Number of impaired waterbodies: 45
    Percent of Lakes, Reservoirs and Ponds in MONTANA assessed by agencies for 1997-98 reporting period: 94%
      Percent Waterbodies Affected
    Sediments 60%
    Flow Alterations 44%
    Nutrients 38%
    Salinity/TDS/Chlorides 22%
    Noxious Aquatic Plants 22%
    More...

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




    Fresh Water Wetlands
    Number of impaired waterbodies: 2 (cause not reported for 50%)
      Percent Waterbodies Affected
    Nutrients 50%
    Noxious Aquatic Plants 50%
    Organic Compounds 50%
    Flow Alterations 50%

    NOTE: Possible inconsistencies between data on (a) impaired waterbodies and (b) percentage of waterbodies assessed.
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  • Leading Sources of Water Quality Problems
    Rivers, Streams, and Creeks
    Number of impaired waterbodies: 819 (cause not reported for 1%)
    Percent of Rivers, Streams and Creeks in MONTANA assessed by agencies for 1997-98 reporting period: 10%
      Percent Waterbodies Affected
    Agriculture 76%
    Resource Extraction 26%
    Silviculture 26%
    Hydromodification/Habitat Modification 25%
    Natural Sources 21%
    More...

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


    Lakes, Reservoirs, and Ponds
    Number of impaired waterbodies: 45 (cause not reported for 8%)
    Percent of Lakes, Reservoirs and Ponds in MONTANA assessed by agencies for 1997-98 reporting period: 94%
      Percent Waterbodies Affected
    Agriculture 73%
    Natural Sources 27%
    Construction 16%
    Silviculture 16%
    Hydromodification/Habitat Modification 13%
    More...

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




    Fresh Water Wetlands
    Number of impaired waterbodies: 2 (cause not reported for 50%)
      Percent Waterbodies Affected
    Agriculture 50%
    Impairment source not reported 50%
    Other Sources 50%
    Septic Systems 50%
    Urban Runoff/Storm Sewers 50%

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