Jump to main content.


Return to home page

On This Page 303(d) Listed Waters for 2014

Data are also available for these cycles:
2002 2004 2006 2008 2010 2012

Waterbody Changes from Prior Cycle

For More Information:

Download Excel compatible information

Download GIS Information

Montana Water Quality Assessment Report

Assessed Waters of Montana by Watershed

Select a watershed from the list:
or click on the map to choose a watershed:
Search for a waterbody within Montana
Enter Waterbody Name:
Display impaired waters and TMDL information only



Site-specific Targeted Monitoring Summary Results

Montana (2014)

Description of this table
 
    3,119.3 69,767.4
       251.7
    8,108.2
                3,273.6
                
                1,517.2
                3,317.4
    17,159.2 415,360.8
           3,440.0     2,525.4
                
           1,976.6     9,929.1
           11,742.7     402,906.3
              916.3     .0
                    10,826.4           402,906.3
20,278.5 493,236.4
176,750.0 844,802.0
11.5 58.4

Top of page


Summary of Water Quality Assessments for Each Waterbody Type
for Reporting Year 2014


Site-specific Targeted Monitoring Results

Montana Rivers and Streams 2014

Description of this table

All
Rivers and Streams

176,750.0 Miles of Rivers and Streams

Assessed 20,278.5
Unassessed 156,471.5
Total Miles 176,750.0







arrow pointing right
Description of this table

Assessed
Rivers and Streams

20,278.5 Miles of
Assessed Rivers and Streams

Good 3,119.3
Threatened .0
Impaired 17,159.2
Total Miles Assessed 20,278.5







arrow pointing right
Description of this table

Threatened and Impaired
Rivers and Streams

17,159.2 Miles of
Threatened and Impaired
Rivers and Streams

4,356.3
.0
1,976.6
10,826.4
Total Threatened and Impaired 17,159.2

Top of page

Site-specific Targeted Monitoring Results

Individual Designated Use Support
Montana Rivers and Streams 2014

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

Description of this table
% Good
% Threatened
% Impaired
Agricultural 13,363.1 85.7 .0 14.3 color.gifcolor.gif
Aquatic Life 19,027.4 16.4 .0 83.6 color.gifcolor.gif
Drinking Water 11,911.3 70.7 .0 29.3 color.gifcolor.gif
Primary Contact Recreation 15,493.5 61.3 .0 38.7 color.gifcolor.gif

Top of page

Site-specific Targeted Monitoring Results

Causes of Impairment
Montana Rivers and Streams 2014

Description of this table
Alteration in Stream-Side or Littoral Vegetative Covers Habitat Alterations color.gif 8,352.5
Sedimentation/Siltation Sediment color.gif 7,455.6
Phosphorus, Total Nutrients color.gif 5,091.4
Low Flow Alterations Flow Alteration(s) color.gif 4,936.1
Nitrogen, Total Nutrients color.gif 4,845.6
Physical Substrate Habitat Alterations Habitat Alterations color.gif 3,463.0
Lead Metals (other than Mercury) color.gif 3,293.9
Copper Metals (other than Mercury) color.gif 2,911.0
Temperature, Water Temperature color.gif 2,647.1
Iron Metals (other than Mercury) color.gif 2,563.4
Nitrate/Nitrite (Nitrite + Nitrate as N) Nutrients color.gif 2,414.2
Cadmium Metals (other than Mercury) color.gif 1,778.7
Mercury Mercury color.gif 1,762.5
Salinity Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 1,698.9
Zinc Metals (other than Mercury) color.gif 1,645.7
Arsenic Metals (other than Mercury) color.gif 1,642.5
Chlorophyll-A Algal Growth color.gif 1,492.5
Other Flow Regime Alterations Flow Alteration(s) color.gif 1,386.8
Total Dissolved Solids (TDS) Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 1,319.5
Solids (Suspended/Bedload) Sediment color.gif 1,245.5
Sulfates Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 703.3
Aluminum Metals (other than Mercury) color.gif 541.9
Escherichia Coli (E. Coli) Pathogens color.gif 523.4
Fish Passage Barrier Habitat Alterations color.gif 523.0
Dissolved Oxygen Organic Enrichment/Oxygen Depletion color.gif 494.2
Specific Conductivity Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 473.3
Other Anthropogenic Substrate Alterations Habitat Alterations color.gif 398.0
Total Kjehldahl Nitrogen (TKN) Nutrients color.gif 378.7
pH pH/Acidity/Caustic Conditions color.gif 353.6
Selenium Metals (other than Mercury) color.gif 348.3
Excess Algal Growth Algal Growth color.gif 335.2
Chromium, Total Metals (other than Mercury) color.gif 297.8
Nickel Metals (other than Mercury) color.gif 206.9
Ammonia, Un-ionized Ammonia color.gif 203.4
Organic Enrichment (Sewage) Biological Indicators Organic Enrichment/Oxygen Depletion color.gif 186.9
Cause Unknown Cause Unknown color.gif 183.8
Turbidity Turbidity color.gif 168.6
High Flow Regime Flow Alteration(s) color.gif 160.9
Total Suspended Solids (TSS) Turbidity color.gif 125.3
Oil and Grease Oil and Grease color.gif 113.1
Other Cause Other Cause color.gif 111.8
Manganese Metals (other than Mercury) color.gif 104.7
Cyanide Toxic Inorganics color.gif 96.5
Uranium Radiation color.gif 86.9
Benthic Macroinvertebrates Bioassessments Cause Unknown - Impaired Biota color.gif 84.7
Nitrates Nutrients color.gif 84.5
Sodium Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 75.7
Ammonia, Total Ammonia color.gif 65.7
Biochemical Oxygen Demand (BOD) Organic Enrichment/Oxygen Depletion color.gif 64.2
Antimony Toxic Inorganics color.gif 58.3
Polychlorinated Biphenyls (PCBs) Polychlorinated Biphenyls (PCBs) color.gif 47.3
Alterations in Wetland Habitats Habitat Alterations color.gif 46.9
Dissolved Gas Supersaturation Other Cause color.gif 39.2
Silver Metals (other than Mercury) color.gif 37.5
Nutrient/Eutrophication Biological Indicators Nutrients color.gif 33.2
Bottom Deposits Sediment color.gif 30.6
PCB in Water Column Polychlorinated Biphenyls (PCBs) color.gif 24.8
DDE Pesticides color.gif 22.1
Polycyclic Aromatic Hydrocarbons (PAHs) (Aquatic Ecosystems) Toxic Organics color.gif 21.8
Nitrogen, Nitrate Nutrients color.gif 18.5
Chloride Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 17.6
Combined Biota/Habitat Bioassessments (Streams) Cause Unknown - Impaired Biota color.gif 13.4
Aquatic Plants - Native Nuisance Native Species color.gif 13.0
Non-Native Fish/Shellfish/Zooplankton Nuisance Exotic Species color.gif 11.0
Periphyton (Aufwuchs) Indicator Bioassessments (Streams) Cause Unknown - Impaired Biota color.gif 10.6
Dissolved Oxygen Saturation Organic Enrichment/Oxygen Depletion color.gif 10.6
Thallium Metals (other than Mercury) color.gif 7.9
Fecal Coliform Pathogens color.gif 6.2
Beryllium Metals (other than Mercury) color.gif 5.4

Top of page

Site-specific Targeted Monitoring Results

Probable Sources
Montana Rivers and Streams 2014

Description of this table
Agriculture Agriculture color.gif 5,999.9
Grazing In Riparian Or Shoreline Zones Agriculture color.gif 5,861.7
Irrigated Crop Production Agriculture color.gif 4,570.1
Natural Sources Natural/Wildlife color.gif 4,518.5
Source Unknown Unknown color.gif 4,223.4
Streambank Modifications/Destablization Hydromodification color.gif 2,553.1
Impacts From Hydrostructure Flow Regulation/Modification Hydromodification color.gif 2,275.8
Rangeland Grazing Agriculture color.gif 2,181.8
Impacts From Abandoned Mine Lands (Inactive) Resource Extraction color.gif 2,079.1
Channelization Hydromodification color.gif 1,993.3
Loss Of Riparian Habitat Habitat Alterations (Not Directly Related To Hydromodification) color.gif 1,877.7
Flow Alterations From Water Diversions Hydromodification color.gif 1,464.0
Dam Or Impoundment Hydromodification color.gif 1,325.5
Highways, Roads, Bridges, Infrasturcture (New Construction) Construction color.gif 1,114.7
Forest Roads (Road Construction And Use) Silviculture (Forestry) color.gif 979.9
Crop Production (Crop Land Or Dry Land) Agriculture color.gif 858.4
Silviculture Activities Silviculture (Forestry) color.gif 835.0
Municipal Point Source Discharges Municipal Discharges/Sewage color.gif 830.7
Mine Tailings Resource Extraction color.gif 708.6
Acid Mine Drainage Resource Extraction color.gif 697.4
Highway/Road/Bridge Runoff (Non-Construction Related) Urban-Related Runoff/Stormwater color.gif 680.0
Non-Irrigated Crop Production Agriculture color.gif 678.7
Unspecified Unpaved Road Or Trail Urban-Related Runoff/Stormwater color.gif 678.1
Site Clearance (Land Development Or Redevelopment) Construction color.gif 579.2
Dam Construction (Other Than Upstream Flood Control Projects) Hydromodification color.gif 518.7
Silviculture Harvesting Silviculture (Forestry) color.gif 510.7
Habitat Modification - Other Than Hydromodification Habitat Alterations (Not Directly Related To Hydromodification) color.gif 482.9
Mill Tailings Industrial color.gif 440.1
Animal Feeding Operations (Nps) Agriculture color.gif 436.7
Livestock (Grazing Or Feeding Operations) Agriculture color.gif 373.3
Subsurface (Hardrock) Mining Resource Extraction color.gif 301.3
Placer Mining Resource Extraction color.gif 273.6
Contaminated Sediments Legacy/Historical Pollutants color.gif 268.5
Industrial Point Source Discharge Industrial color.gif 234.2
Transfer Of Water From An Outside Watershed Hydromodification color.gif 196.1
Residential Districts Urban-Related Runoff/Stormwater color.gif 191.8
On-Site Treatment Systems (Septic Systems And Similar Decencentralized Systems) Municipal Discharges/Sewage color.gif 174.3
Dredge Mining Resource Extraction color.gif 157.7
Managed Pasture Grazing Agriculture color.gif 145.6
Hydrostructure Impacts On Fish Passage Hydromodification color.gif 143.3
Drought-Related Impacts Natural/Wildlife color.gif 133.4
Surface Mining Resource Extraction color.gif 131.2
Upstream Source Other color.gif 125.7
Above Ground Storage Tank Leaks (Tank Farms) Spills/Dumping color.gif 117.3
Post-Development Erosion And Sedimentation Hydromodification color.gif 116.7
Pipeline Breaks Spills/Dumping color.gif 110.1
Watershed Runoff Following Forest Fire Silviculture (Forestry) color.gif 101.7
Impacts From Resort Areas (Winter And Non-Winter Resorts) Recreation And Tourism (Non-Boating) color.gif 97.4
Golf Courses Recreation And Tourism (Non-Boating) color.gif 96.8
Wet Weather Discharges (Point Source And Combination Of Stormwater, Sso Or Cso) Municipal Discharges/Sewage color.gif 82.7
Hardrock Mining Discharges (Permitted) Resource Extraction color.gif 77.7
Upstream Impoundments (E.G., Pl-566 Nrcs Structures) Hydromodification color.gif 77.3
Coal Mining Resource Extraction color.gif 66.5
Permitted Runoff From Confined Animal Feeding Operations (Cafos) Agriculture color.gif 64.2
Atmospheric Deposition - Nitrogen Atmospheric Deposition color.gif 62.9
Channel Erosion/Incision From Upstream Hydromodifications Hydromodification color.gif 55.3
Low Water Crossing Other color.gif 51.6
Aquaculture (Permitted) Aquaculture color.gif 51.4
Municipal (Urbanized High Density Area) Urban-Related Runoff/Stormwater color.gif 45.6
Crop Production With Subsurface Drainage Agriculture color.gif 45.3
Sand/Gravel/Rock Mining Or Quarries Resource Extraction color.gif 41.3
Unspecified Urban Stormwater Urban-Related Runoff/Stormwater color.gif 31.1
Unrestricted Cattle Access Agriculture color.gif 29.6
Rural (Residential Areas) Other color.gif 29.4
Sediment Resuspension (Clean Sediment) Hydromodification color.gif 28.9
Atmospheric Deposition - Toxics Atmospheric Deposition color.gif 28.6
Spills From Trucks Or Trains Spills/Dumping color.gif 27.5
Septage Disposal Municipal Discharges/Sewage color.gif 25.6
Yard Maintenance Urban-Related Runoff/Stormwater color.gif 25.5
Accidental Release/Spill Spills/Dumping color.gif 24.8
Leaking Underground Storage Tanks Land Application/Waste Sites/Tanks color.gif 24.6
Coal Mining Discharges (Permitted) Resource Extraction color.gif 24.1
Other Recreational Pollution Sources Recreation And Tourism (Non-Boating) color.gif 22.6
Petroleum/Natural Gas Production Activities (Permitted) Industrial color.gif 21.8
Wastes From Pets Urban-Related Runoff/Stormwater color.gif 17.9
Wet Weather Discharges (Non-Point Source) Urban-Related Runoff/Stormwater color.gif 15.0
Construction Stormwater Discharge (Permitted) Construction color.gif 14.3
Discharges From Municipal Separate Storm Sewer Systems (Ms4) Urban-Related Runoff/Stormwater color.gif 13.2
Freshets Or Major Flooding Natural/Wildlife color.gif 11.6
Open Pit Mining Resource Extraction color.gif 10.6
Potash Mining Resource Extraction color.gif 8.8
Industrial/Commercial Site Stormwater Discharge (Permittted) Urban-Related Runoff/Stormwater color.gif 7.0
Wildlife Other Than Waterfowl Natural/Wildlife color.gif 6.8
Waterfowl Natural/Wildlife color.gif 6.2
Urban Runoff/Storm Sewers Urban-Related Runoff/Stormwater color.gif 4.9
Baseflow Depletion From Groundwater Withdrawals Hydromodification color.gif 4.8
Heap-Leach Extraction Mining Resource Extraction color.gif 3.8
Manure Runoff Agriculture color.gif 3.6
Erosion From Derelict Land (Barren Land) Hydromodification color.gif 3.1
Sources Outside State Jurisdiction Or Borders Other color.gif 2.9

Top of page


Site-specific Targeted Monitoring Results

Montana Lakes, Reservoirs, and Ponds 2014

Description of this table

All
Lakes, Reservoirs, and Ponds

844,802.0 Acres of Lakes, Reservoirs, and Ponds

Assessed 493,236.4
Unassessed 351,565.6
Total Acres 844,802.0







arrow pointing right
Description of this table

Assessed
Lakes, Reservoirs, and Ponds

493,236.4 Acres of
Assessed Lakes, Reservoirs, and Ponds

Good 69,767.4
Threatened 8,108.2
Impaired 415,360.8
Total Acres Assessed 493,236.4







arrow pointing right
Description of this table

Threatened and Impaired
Lakes, Reservoirs, and Ponds

423,469.0 Acres of
Threatened and Impaired
Lakes, Reservoirs, and Ponds

5,799.0
.0
11,446.3
406,223.7
Total Threatened and Impaired 423,469.0

Top of page

Site-specific Targeted Monitoring Results

Individual Designated Use Support
Montana Lakes, Reservoirs, and Ponds 2014

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

Description of this table
% Good
% Threatened
% Impaired
Agricultural 230,967.7 77.9 .0 22.1 color.gifcolor.gif
Aquatic Life 492,938.4 21.6 1.6 76.7 color.gifcolor.gifcolor.gif
Drinking Water 447,761.6 34.5 .0 65.5 color.gifcolor.gif
Primary Contact Recreation 476,098.7 86.5 .0 13.5 color.gifcolor.gif

Top of page

Site-specific Targeted Monitoring Results

Causes of Impairment
Montana Lakes, Reservoirs, and Ponds 2014

Description of this table
Mercury Mercury color.gif 311,192.3
Lead Metals (other than Mercury) color.gif 246,949.9
Phosphorus, Total Nutrients color.gif 73,324.1
Sedimentation/Siltation Sediment color.gif 69,411.4
Nitrogen, Total Nutrients color.gif 68,353.5
Polychlorinated Biphenyls (PCBs) Polychlorinated Biphenyls (PCBs) color.gif 60,622.4
Other Flow Regime Alterations Flow Alteration(s) color.gif 48,101.6
Selenium Metals (other than Mercury) color.gif 42,271.3
Excess Algal Growth Algal Growth color.gif 38,155.1
Arsenic Metals (other than Mercury) color.gif 38,099.9
Thallium Metals (other than Mercury) color.gif 32,810.0
Ammonia, Un-ionized Ammonia color.gif 32,810.0
Salinity Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 13,292.3
Cadmium Metals (other than Mercury) color.gif 9,726.1
Sulfates Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 8,804.8
Physical Substrate Habitat Alterations Habitat Alterations color.gif 8,764.8
Dissolved Oxygen Organic Enrichment/Oxygen Depletion color.gif 5,699.4
Other Anthropogenic Substrate Alterations Habitat Alterations color.gif 4,417.6
Low Flow Alterations Flow Alteration(s) color.gif 3,757.8
Cause Unknown Cause Unknown color.gif 3,757.8
Chromium, Total Metals (other than Mercury) color.gif 3,757.8
Chlorophyll-A Algal Growth color.gif 3,675.7
Total Dissolved Solids (TDS) Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 3,459.7
BOD, Sediment Load (Sediment Oxygen Demand) Organic Enrichment/Oxygen Depletion color.gif 3,273.6
Nitrate/Nitrite (Nitrite + Nitrate as N) Nutrients color.gif 3,190.0
Endrin Aldehyde Pesticides color.gif 3,190.0
DDT Pesticides color.gif 3,190.0
Endosulfan Sulfate Pesticides color.gif 3,190.0
Aquatic Plants - Native Nuisance Native Species color.gif 3,013.2
Solids (Suspended/Bedload) Sediment color.gif 2,158.5
Iron Metals (other than Mercury) color.gif 1,849.1
Copper Metals (other than Mercury) color.gif 1,849.1
Total Kjehldahl Nitrogen (TKN) Nutrients color.gif 350.9
Other Cause Other Cause color.gif 73.6
Alteration in Stream-Side or Littoral Vegetative Covers Habitat Alterations color.gif 21.0

Top of page

Site-specific Targeted Monitoring Results

Probable Sources
Montana Lakes, Reservoirs, and Ponds 2014

Description of this table
Impacts From Abandoned Mine Lands (Inactive) Resource Extraction color.gif 279,490.5
Atmospheric Deposition - Toxics Atmospheric Deposition color.gif 250,569.9
Historic Bottom Deposits (Not Sediment) Legacy/Historical Pollutants color.gif 237,653.8
Municipal Point Source Discharges Municipal Discharges/Sewage color.gif 97,542.4
Source Unknown Unknown color.gif 86,867.5
Impacts From Hydrostructure Flow Regulation/Modification Hydromodification color.gif 75,897.7
Agriculture Agriculture color.gif 58,401.0
Atmospheric Deposition - Nitrogen Atmospheric Deposition color.gif 57,305.0
Upstream Impoundments (E.G., Pl-566 Nrcs Structures) Hydromodification color.gif 57,305.0
Silviculture Harvesting Silviculture (Forestry) color.gif 57,305.0
Unspecified Urban Stormwater Urban-Related Runoff/Stormwater color.gif 57,305.0
Natural Sources Natural/Wildlife color.gif 43,685.8
Acid Mine Drainage Resource Extraction color.gif 41,836.7
On-Site Treatment Systems (Septic Systems And Similar Decencentralized Systems) Municipal Discharges/Sewage color.gif 36,000.0
Site Clearance (Land Development Or Redevelopment) Construction color.gif 32,810.0
Internal Nutrient Recycling Natural/Wildlife color.gif 32,810.0
Dam Or Impoundment Hydromodification color.gif 32,806.7
Sources Outside State Jurisdiction Or Borders Other color.gif 28,874.5
Irrigated Crop Production Agriculture color.gif 26,009.0
Grazing In Riparian Or Shoreline Zones Agriculture color.gif 9,871.7
Silviculture Activities Silviculture (Forestry) color.gif 8,024.6
Rangeland Grazing Agriculture color.gif 7,243.4
Forest Roads (Road Construction And Use) Silviculture (Forestry) color.gif 6,591.0
Upstream Source Other color.gif 5,164.5
Drought-Related Impacts Natural/Wildlife color.gif 4,922.1
Placer Mining Resource Extraction color.gif 4,358.0
Inappropriate Waste Disposal Spills/Dumping color.gif 4,358.0
Highways, Roads, Bridges, Infrasturcture (New Construction) Construction color.gif 3,954.4
Habitat Modification - Other Than Hydromodification Habitat Alterations (Not Directly Related To Hydromodification) color.gif 3,757.8
Dam Construction (Other Than Upstream Flood Control Projects) Hydromodification color.gif 3,190.0
Contaminated Sediments Legacy/Historical Pollutants color.gif 3,190.0
Highway/Road/Bridge Runoff (Non-Construction Related) Urban-Related Runoff/Stormwater color.gif 3,190.0
Mine Tailings Resource Extraction color.gif 3,190.0
Low Water Crossing Other color.gif 2,217.5
Non-Irrigated Crop Production Agriculture color.gif 659.8
Upstream/Dowstream Source Other color.gif 350.9
Petroleum/Natural Gas Activities Resource Extraction color.gif 21.0

Top of page



Montana Causes of Impairment for Reporting Year 2014


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. See also Pollution categories summary document (PDF) (20 pp, 557K, About PDF) for brief, non-technical descriptions of general cause categories.
Size of Assessed Waters with Listed Causes of Impairment
Algal Growth 1,827.7 41,830.8
Ammonia 269.1 32,810.0
Cause Unknown 183.8 3,757.8
Cause Unknown - Impaired Biota 98.2
Flow Alteration(s) 6,462.5 51,859.4
Habitat Alterations 9,808.5 9,445.6
Mercury 1,762.5 311,192.3
Metals (other than Mercury) 5,496.2 329,000.0
Nuisance Exotic Species 11.0
Nuisance Native Species 13.0 3,013.2
Nutrients 6,876.4 78,669.2
Oil and Grease 113.1
Organic Enrichment/Oxygen Depletion 756.0 8,973.0
Other Cause 150.9 73.6
Pathogens 523.4
Pesticides 22.1 3,190.0
pH/Acidity/Caustic Conditions 353.6
Polychlorinated Biphenyls (PCBs) 72.1 60,622.4
Radiation 86.9
Salinity/Total Dissolved Solids/Chlorides/Sulfates 2,846.9 16,305.5
Sediment 8,303.5 71,569.9
Temperature 2,647.1
Toxic Inorganics 151.0
Toxic Organics 21.8
Turbidity 293.9

Top of page



Montana Probable Sources Contributing to Impairments
for Reporting Year 2014

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.
Size of Assessed Waters with Probable Sources of Impairments
Agriculture 12,570.6 72,332.8
Aquaculture 51.4
Atmospheric Deposition 91.5 307,874.9
Construction 1,564.4 36,764.4
Habitat Alterations (Not Directly Related To Hydromodification) 2,248.3 3,757.8
Hydromodification 7,237.8 108,704.4
Industrial 637.2
Land Application/Waste Sites/Tanks 24.6
Legacy/Historical Pollutants 268.5 240,843.8
Municipal Discharges/Sewage 1,102.8 97,542.4
Natural/Wildlife 4,676.5 48,607.9
Other 206.6 34,389.9
Recreation And Tourism (Non-Boating) 216.7
Resource Extraction 2,944.5 279,511.5
Silviculture (Forestry) 1,849.6 68,603.2
Spills/Dumping 279.7 4,358.0
Unknown 4,223.4 86,867.5
Urban-Related Runoff/Stormwater 1,611.2 60,495.0

Top of page


Montana TMDL Alternatives by Cause of Impairment 2014


No TMDL Alternatives reported.

Top of page



Montana Previously 303(d)-Listed Waters Now Attaining All Applicable Water Quality Standards

Description of this table
NOTE: Click on the underlined "Number of Waters Attaining" value for a detailed list of those previously 303(d)-listed waters now attaining all applicable water quality standards.
2010 color.gif 1 1
2011 color.gif 2 2
2014 color.gif 5 10

Top of page


Montana 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.
Nutrients color.gif 371
Metals (other than Mercury) color.gif 346
Sediment color.gif 203
Temperature color.gif 63
Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 63
Mercury color.gif 39
Organic Enrichment/Oxygen Depletion color.gif 20
Pathogens color.gif 12
Ammonia color.gif 10
Turbidity color.gif 8
pH/Acidity/Caustic Conditions color.gif 6
Cause Unknown - Impaired Biota color.gif 6
Polychlorinated Biphenyls (PCBs) color.gif 5
Oil and Grease color.gif 4
Toxic Inorganics color.gif 4
Other Cause color.gif 4
Pesticides color.gif 4
Radiation color.gif 1
Toxic Organics color.gif 1
Nuisance Exotic Species color.gif 1
Habitat Alterations color.gif 1

Total: 1,172 Causes of Impairment

Top of page



Montana 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.
Number of Causes of
Impairment Addressed
Sediment color.gif 255 380
Lead color.gif 122 125
Copper color.gif 111 115
Cadmium color.gif 96 103
Arsenic color.gif 87 88
Zinc color.gif 87 89
Nitrogen, Total color.gif 78 96
Phosphorus, Total color.gif 77 86
Iron color.gif 67 68
Sedimentation/Siltation color.gif 58 60
Aluminum color.gif 43 43
Temperature color.gif 36 42
Phosphorus color.gif 30 43
Mercury color.gif 27 27
Nitrogen color.gif 21 29
Siltation color.gif 19 19
Selenium color.gif 13 13
Manganese color.gif 12 12
Thermal Modifications color.gif 10 10
Suspended Solids color.gif 9 9
Total Dissolved Solids (TDS) color.gif 9 17
Cyanide color.gif 8 8
Fecal Coliform color.gif 8 8
Nitrate/Nitrite color.gif 8 9
Antimony color.gif 7 7
Escherichia Coli (E. Coli) color.gif 7 7
Fecal color.gif 7 9
Nickel color.gif 7 7
Nitrite/Nitrate color.gif 7 7
Total Residual Chlorine color.gif 6 6
Total Suspended Solids (TSS) color.gif 6 7
Ammonia color.gif 5 5
Nitrate color.gif 4 4
Silver color.gif 4 4
Chromium, Total color.gif 3 3
Salinity color.gif 3 4
Tin color.gif 3 3
pH color.gif 3 3
Nitrates color.gif 2 2
Polychlorinated Biphenyls (PCBs) color.gif 2 2
Salinity/Total Dissolved Solids/Sulfates color.gif 2 2
Sulfates color.gif 2 2
Turbidity color.gif 2 2
Beryllium color.gif 1 1
Biochemical Oxygen Demand (BOD) color.gif 1 1
Fluoride color.gif 1 1
Noxious Aquatic Plants color.gif 1 1
Nutrients color.gif 1 3
Sulfate color.gif 1 1
Thallium color.gif 1 1
Total Toxics color.gif 1 1

Total: 1,381 TMDLs; 1,595 Causes of Impairment Addressed


Top of page


Montana 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.
1997 color.gif 10 10
1998 color.gif 32 37
1999 color.gif 18 33
2001 color.gif 1 1
2002 color.gif 16 20
2003 color.gif 46 49
2004 color.gif 56 75
2005 color.gif 67 73
2006 color.gif 124 127
2007 color.gif 34 36
2008 color.gif