This searchable database contains an extensive compendium of numeric water quality thresholds from the literature for over 860 chemical constituents and water quality parameters. Included are: * California and Federal Drinking Water Standards (MCLs) * California Public Health Goals (PHGs) * California State Notification and Response Levels for Drinking Water * Health Advisories, Water Quality Advisories, and Drinking Water Advisories * Suggested No-Adverse-Response Levels (SNARLs) * Cancer Risk Estimates * Health-based criteria from USEPA Integrated Risk Information System (IRIS) * Proposition 65 Safe Harbor Levels * California Toxics Rule Criteria to Protect Human Health and Aquatic Life * California Ocean Plan Water Quality Objectives * USEPA Recommended Criteria to Protect Human Health and Aquatic Life * Agricultural Use Protective Limits * Taste and Odor Based Criteria
These thresholds may be used to assess whether beneficial uses of surface water or groundwater are likely to be impaired or threatened. Water Quality Goals is technical information provided by staff of the State Water Resources Control Board, Division of Water Quality. It is intended to be used only as an informational tool and does not reflect State Water Board policy or regulation. The information in the Water Quality Goals database is current as of February 14, 2017.
To avoid improper use of the numeric thresholds contained in the database, users are strongly encouraged to carefully review theWater Quality Goals Staff Report. * Search Page * How to use Water Quality Goals Online
Assessment Thresholds Table (MS Excel format, 2007 or later version)
Based on the Assessment Threshold Algorithms in the Water Quality Goals Staff Report, this table presents numeric thresholds recommended to implement selected water quality objectives and promulgated water quality criteria, as well as assessment thresholds recommended to protect specified beneficial uses in groundwater, inland surface waters, enclosed bays and estuaries, and ocean waters.
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Please contact:
* Lisa Holmes
Email: lisa.holmes@waterboards.ca.gov
Phone (916) 341-5557
The data from the Water Quality Goals database are available for download. * Tab Delimited Text format (txt) - For import into database or spreadsheet programs * Water Quality Threshold Tables (txt) * Footnotes (txt) * References (txt) * Data Dictionary - A key to field names used in the database tables.
(Page last updated 2/12/26) Water is a precious resource in California, and maintaining its quality is of utmost importance to safeguard the health of the public and the environment.
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