MT DEQ's Clean Water Act Information Center (replaced Environet)

R Provides information on the condition of all water bodies in the state (305 b report), identifies which water bodies are impaired and the suspected causes and sources of the impairment, and indicates whether impaired water bodies have an approved water quality restoration plan (or TMDL).  Also provides sources of this information and an analysis of the quality of the information. (note --some of the description below was based on Environet, and needs to be updated to reflect CWAIC's characteristics).

Nature and Purpose of Database: CWAIC was developed to convey information about the quality of Montana's rivers, streams, lakes and wetlands in relation to the Montana Water Quality Standards. CWAIC is a joint effort of the Montana Department of Environmental Quality (provides the water information) and Montana State Library's Natural Resource Information System (provides public access to the information through this interactive online application).

The water quality assessment information available through CWAIC is stored in DEQ's Water body Assessment Database which contains summary information from a statewide inventory of water quality data sources. This summary information includes uses of water bodies, the extent to which these uses are supported, probable causes and sources of use impairment, and information on the quality of data used to make this assessment. It does not include any 'raw' water quality data.

CWAIC provides the ability to search out statewide water quality information by geographic criteria (water body name, watershed, county or all 3) or by various water quality assessment criteria (water use-support status, suspected pollution problems and sources, or combinations of these). As the user specifies more criteria, the search is focused on fewer water bodies. CWAIC provides the user with the ability to perform custom data queries, to develop summary water quality reports for all water bodies in the area specified, and to generate maps of the water bodies meeting the search criteria. 

The Clean Water Act requires that states periodically publish a report on the condition of waterbodies in each state (305 b report) and a list of impaired water bodies (303d list). CWAIC now provides the main vehicle for public dissemination of this report and list. The report and list are in the form of a database that can be queried. In addition, CWAIC allows the user to view the following parts of the 305 b report:

Introduction & Background

Surface Water Monitoring & Assessment

Ground Water Monitoring & Assessment

  • Appendix A: Waters Monitored & Reassessed - Lacking Sufficient Credible Data (from 2000 303(d) list
  • Appendix B: Waters with Use Support Assessments during the 2006 Reporting Cycle
  • Appendix C: Impairment Causes De-Listed from the 2000 303(d) Reassessment List
  • Appendix D: Beneficial Use Designation Changes from 2004 to 2006
  • Appendix E: Monitoring and Assessment Schedule for 2006 to 2008
  • Appendix F: TMDL Priority Schedule by TPA
  • Appendix G: Montana's EPA Approved TMDLs
  • Appendix H: Impaired Waters (i.e., 303(d) List)

Location of sample sites/areas assessed: Includes streams, lakes and wetlands throughout the state. To specify the upper Clark Fork basin, select 'watershed' and specify either 17010201 for the upper Clark Fork basin or 17010202 for Flint/Rock Creek basin. Alternatively, one may limit the search to specific water bodies, or to those in a specific county.

Nature of location information in database: Data search is focused by water body, watershed, county or any combination.

Time frame: The information in CWAIC (use support, causes & sources of impairment, etc) reflects the most current EPA-approved version (year 2004) of Montana's 303(d) list (list of impaired water bodies). Users may specify which 303(d) list info they wish to view (1996, 2000, 2002, 2004, 2006). This allows the user to look at trends in use support.

Information stored: For each water body: STORET ID, location (county, ecoregion, basin, watershed, hydrologic unit code), waterbody type, designated uses, level of support (full, partial, not supporting, threatened), whether a TMDL has been approved or is required, probable causes of impairment (metals, nutrients, temperature, etc), sources of impairment (abandoned mines, agriculture, etc), a summary of the data used to determine use status, showing the quality/credibility of that data. Currently, a court ruling makes the TMDL priorities meaningless, so these are stored as 'unknown' at present.

Quality of data: Data quality is analyzed to determine whether it meets criteria for sufficient and credible data required to determine use impairment. The data used to determine impairment for a particular water body can be accessed under the 'Full Report' section. (note:  if you are looking at all the streams in a watershed, you will see a dialog box of all the streams in that watershed; once you select a particular stream, you will need to press 'go to' for the data presented to update to that stream). Click on Assessment Record Sheet. Then respond yes to the query about enabling macros. For some streams, you will see a spreadsheet of 3 sheets. One sheet is the Beneficial Use Determination (BUD) assessment which indicates the data used in the assessment and its quality. Other sheets include the assessor's notes. For most streams, you will see a spreadsheet of as many as 9 sheets (references used in the assessment; data used to assess aquatic life & fishery support for streams, or for lakes/wetlands; the data matrix of biological, chemical & physical data used in the assessment; lists of impaired uses, causes & sources of impairment; methods used to collect data used in the assessment). Ultimately, DEQ plans that all stream records in the Upper Clark Fork will include the full 9-sheet assessment information.

Relevant references: 

Water body data used to make these use support assessments were generated following DEQ's standard protocols which are explained at:

These data are stored in the STORET database. DEQ has no other electronic database of 'raw' water quality data.

Responsible party contact info:  Staci Stolp <>
Mt Department of Environmental Quality, Water Quality Planning Bureau
P.O. Box 200901, 1520 East Sixth Avenue, Helena, MT 59620-0901
Phone (406) 444-3409; Fax     (406) 444-6836

Website:   For web site problems, contact:

Recommendations for making the information more useful:

The home page needs an explanation of the meaning & purpose of 305 b reports (status of all waterbodies) and the 303 d lists (list of all impaired water bodies, uses impaired and suspected causes of impairment) and their relationship to the Clean Water Act. It would be clearer to provide this overview on the homepage and then enter the database. In addition, the page should provide some explanation of the sources of the data used & how the data is used to arrive at assessments of impairment. Or at least point out that this information is available in the 305 b reports. The page should also make it clear which reports have been approved & which are still out for comment. Finally, the page states that it is not a source of water quality data -- it would be helpful to state that STORET is the respository of water quality data & provide a link.

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