State-Specific Water Quality Standards Effective under the Clean Water Act (CWA)
Modernizing Public Hearings for WQS Reviews
The document below suggests how states and authorized tribes can conduct online public hearings in lieu of in-person public hearings, consistent with federal public hearing requirements.
EPA has compiled state, territorial, and authorized tribal water quality standards that EPA has approved or are otherwise in effect for Clean Water Act purposes. This compilation is continuously updated as EPA approves new or revised WQS.
In instances when state-specific water quality standards have not been developed or approved by EPA, the Agency will propose and/or promulgate standards for a state until such time as the state submits and EPA approves their own standards. Any federally-proposed or promulgated replacement water quality standards are also identified.
Please note the water quality standards may contain additional provisions outside the scope of the Clean Water Act, its implementing federal regulations, or EPA's authority. In some cases, these additional provisions have been included as supplementary information.
EPA is posting the water quality standards as a convenience to users and has made a reasonable effort to assure their accuracy. Additionally, EPA has made a reasonable effort to identify parts of the standards that are approved, disapproved, or are otherwise not in effect for Clean Water Act purposes.
Please contact the appropriate Regional EPA Water Quality Standards coordinator for questions about water quality standards for a particular state, tribe, or territory...
Select Water Quality Standards Information for a Specific State, Territory, or Tribe
Each state, territory, and authorized tribe has a page on this website containing information about their relevant WQS, including those in effect for CWA purposes. Other information may also be included (for example, contact information, federal promulgations, etc.). Select the state on the map or using the Select state, territory, or authorized tribe selector.
Search State Criteria
EPA has extracted numeric criteria data for pollutants and other parameters from state WQS regulations in effect for CWA purposes and organized them into this criteria search tool. This tool also includes the following criteria that EPA has recommended or promulgated:
Criteria from additional sources will likely be added to the tool in the future, such as those from territories and authorized tribes.
Important!
- The numeric criteria data summarized in this tool are not a substitute for those in the source WQS regulations that EPA has approved or are otherwise in effect for CWA purposes.
- The tool points to the source regulations that provide contextual details such as duration, frequency, and other nuances as to how the criteria are applied.
- Narrative criteria - which are not included in this search tool - are included in the source WQS regulations that were used for the numeric criteria.
How to Use this Tool
Using this tool, you can identify water quality criteria from the following two search perspectives:
- Search by Parameter - Use this perspective if you'd like to compare magnitudes and applications for a specific parameter from various states.
- Search by State - Use this perspective if you'd like a comprehensive overview of magnitudes and applications for parameters within a specific state.
Both perspectives organize criteria using the magnitude values of parameters as related to each state's application of the parameter. The source linking the criterion to EPA-approved state regulation is also included.
Application
Criteria applications are generally direct or indirect expressions of the related designated uses which depend on the particular state's regulations. Direct applications explicitly specify the designated uses to which the criterion applies (e.g., water supply). Indirect applications indicate one or more waterbodies or classes of waterbodies to which the criterion applies; the actual designated uses for these waters are identified elsewhere in the state’s regulations or other supporting documents.
Note: Names for a specific designated use can vary between states. For example, drinking water supply, municipal supply, and potable water supply are names for the same designated use.
Parameter
A parameter is a specific characteristic of the water body; it can be chemical (e.g., concentrations of particular substances, conductivity, etc.) or physical (e.g., temperature, flow conditions, clarity, etc.).
Note: Parameter names can vary from state to state. For example, silvex is the same parameter as 2,4,5-trichlorophenoxy proprionic acid. EPA has made a reasonable effort to link pollutants with their synonyms so you'll be presented with a more complete listing of a pollutant's criteria across states.
For chemical parameters, a link is provided to the chemical on EPA's CompTox Chemicals Dashboard. The dashboard is a comprehensive source for chemistry, toxicity, and exposure information for over 875,000 chemicals.
Magnitude
Currently, only criteria magnitudes for parameters are summarized in the tool. Durations, frequencies, and other factors may be included in the state's regulation.
Note: Magnitudes for site-specific criteria may be presented as a range in the tool. Criteria for the individual sites are included in the state regulation.
Source
To provide context and details for the specific criterion (or criteria), each row has a button that links to the PDF page
PDF pageThis is the page number as indicated by the PDF file viewer. It is often not what's printed on the document itself. of the state regulation in-effect for CWA purposes. These source documents are also located on the state's WQS Information page.
Search Criteria by State
Select the state below to generate the criteria table. Each criterion has a button that links to the source regulation to provide appropriate context.
Note: Clicking the button should open the regulation to the PDF pagePDF pageThis is the page number as indicated by the PDF file viewer. It is often not what's printed on the document itself.. Otherwise, the source button indicates the appropriate page as indicated by the PDF file viewer.
Search Criteria by Parameter
To select a parameter, start typing it into the box below. Doing so will generate a list of parameters included in the tool's database. For parameters that are chemical substances, you can also select pollutants using its CAS Number without any dashes (e.g., 93721 — not 93-72-1).
Once you see your parameter-of-interest, select it to generate the criteria table. In many cases, the table will include parameters listed under different names (synonyms) depending on the state. Each criterion has a button that links to the source regulation to provide appropriate context.
Note: Clicking the button should open the regulation to the PDF pagePDF pageThis is the page number as indicated by the PDF file viewer. It is often not what's printed on the document itself.. Otherwise, the source button indicates the appropriate page as indicated by the PDF file viewer.
Download Criteria Spreadsheet
Data from the search tool are available for download as a "flat" spreadsheet file to help support custom searches and analyses.
- State Criteria Data Spreadsheet (Excel)(1 pp, 2.1 MB)