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STOrage and RETrieval and Water Quality eXchange Domain Services and Downloads

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WQX Domain Value Services and Downloads

EPA makes available domains of Water Quality eXchange (WQX) data elements for both submission and retrievals. Domains are publicly accessible to assist others in conforming to a consistent nomenclature. The domain value web service can be queried to determine the EPA-supplied values of the domains used for both submission and retrievals.

1. The Characteristic domain values use the USEPA’s Substance Registry System (SRS). If your substance is not in the WQX domain value, search the SRS or another credible resource, and send the below information for review to the STORET helpdesk at

To Request a new Characteristic provide the following as applicable:

  • Name
  • EPA SRS Number
  • CAS Number
  • Documentation/URL

2. The Taxon domain use the Integrated Taxonomic Information System (ITIS)Exitand the ITIS Catalogue of LifeExitas the credible source for regulating taxa names. However, taxonomic names from academic journals or accredited sources may also be added upon review.

To Request a new Taxon provide the following as applicable:

  • Name
  • Taxon Rank
  • Kingdom, URL
  • Author & Year
  • ITIS Identifier
  • ITIS Parent Identifier (one taxon rank above)

3. The Analytical Method domain values use the National Environmental Methods Index (NEMI)Exit as the credible source for regulating Analytical Method IDs.

To Request a new "National" Method provide the following as applicable:

  • Method ID
  • Method Name
  • Source/Context
  • URL
  • NEMI Identifier

For all other domain value requests, email the STORET Helpdesk with the below information.

  • descriptions
  • definitions
  • and reference

Also, check the STORET website and the Monthly STORET/WQX user conference call notes for information and discussions on system issues and domain values requests.

For a formal definition of the Web Service, please review the Service Description.

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To download the domain lists (as zipped CSV files), click the links below:

Individual Domain Values Lists:

Note: CharacteristicWithPickList* and ResultMeasureValuePickList* are the same or equivalent.

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