Data and Databases - Contaminants


This topic provides links to Water Board databases containing water quality data so that users can make determinations regarding contaminants themselves, links to what might be considered contaminant levels for different purposes and compounds, and a link to reports developed by the Water Boards identifying what we have determined to be impaired waters.

Drinking Water

For Water Quality Inquiries
The Drinking Water Watch Data System allows users to view water quality test results by water system, source, and analyte going back to January 2006 for any public water system in California. It also provides details about the water system and its facilities, details of violations and enforcement actions, site visits, and Consumer Confidence Reports. Users can search for a particular water system by system name or number, county served, or regulating agency. For assistance, please contact this public web portal administrator at

Surface Water

California Environmental Data Exchange Network (CEDEN)
CEDEN is a central location to find and share information about California’s water bodies, including streams, lakes, rivers, and the coastal ocean. Many groups in California monitor water quality, aquatic habitat, and wildlife health to ensure good stewardship of our ecological resources, and CEDEN aggregates this data and makes it accessible to environmental managers and the public. For assistance, please contact the CEDEN administrator at


Stormwater Multi-Application Reporting & Tracking System (SMARTS) Public Reports
Click on the button labeled ‘View SW Data’ to view public reports from the SMARTS program. For assistance, please contact the SMARTS Help Center at or 866-563-3107.


Groundwater Ambient Monitoring and Assessment Program (GAMA)
The Groundwater Ambient Monitoring and Assessment (GAMA) Program conducts comprehensive monitoring of California’s groundwater quality, compiles and standardizes groundwater quality data across several different sources and regulatory programs, and makes that data readily accessible to the public. In addition, the GAMA Program conducts groundwater studies related to groundwater vulnerability, groundwater quality in domestic wells, and groundwater impacts associated with non-point sources of contamination.

  • Comprehensive Groundwater Monitoring
    The primary objective of the GAMA Program is to assess statewide groundwater quality on a comprehensive basis and gain an understanding about contamination risk to groundwater resources. The GAMA Program meets this objective through collaboration with the United States Geological Survey, who provides the technical lead for the design and implementation of statewide monitoring and assessment of trends in groundwater quality. In addition, the GAMA Program contracts with national laboratories and Universities to conduct special studies related to groundwater vulnerability and threats from non-point sources.
  • Data Availability to the Public
    The GAMA Program contracts with a specialized vendor to run a user interface that provides easy public access to the groundwater quality data compiled in the GAMA Program (the GAMA Groundwater Information System). GAMA Program staff work directly with the public and stakeholders to upload data, conduct searches of water quality data, and create online tools to facilitate access to the water quality data and scientific findings throughout the state.

Visit the GAMA Program Online Tools page for more information, and feel free to contact if you have any questions or require assistance.

Nitrate Impacted Water Wells
This interactive tool is intended for private domestic well owners to evaluate if their well is near a nitrate-impacted well. The map interface displays the location of wells with known test results above the nitrate maximum contaminant level (MCL). The blue dots displayed on the map each represent a well with the most recent detection of nitrate above the MCL since 2000. Additionally, this interface allows you to enter an address to see if a nitrate-impacted well is within 2,000 feet of you.

Regulated Facility Monitoring Data

eSMR Analytical Report
This report provides analytical and calculated data provided by NPDES permit holders. The report allows the user to query by a specific facility, agency, or order, or more generally by report type, monitoring location type, or time frame. The data is provided in Microsoft Excel format. The report limits queries to 100,000 data points. For assistance, please contact the CIWQS Help Center at or (866)792-4977.

Stormwater Multi-Application Reporting & Tracking System (SMARTS) Public Reports
Click on the button labeled ‘View SW Data’ to view public reports from the SMARTS program. For assistance, please contact the SMARTS Help Center at or 866-563-3107.

Sanitary Sewer Overflows

Interactive SSO Report

Sanitary sewer system agencies covered under Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (WQO No. 2006-0003-DWQ), referred to as Enrollees, are required to report all Sanitary Sewer Overflows (SSOs) for which their agency has responsibility into the State Water Resources Control Board’s SSO database. Enrollees are also able to report sewage discharges from privately owned laterals or collection systems (known as private lateral sewage discharges, or PLSDs), for which the Enrollee has knowledge of the event but is not responsible, on a voluntary basis. The SSO Report allows users to view summary information of SSOs and PLSDs reported by Enrollees, as well as complete reports submitted for specific sewage discharge locations. For assistance, please contact the CIWQS Help Center at or (866)792-4977.

Water Quality Goals and Objectives

Water Quality Goals
This searchable database contains an extensive compendium of numeric water quality thresholds for over 860 chemical constituents and water quality parameters. For more information, please visit the instructions webpage.

Impaired Water Bodies

303(d) Reports
Select the tab labeled ‘303(d) List’ near the bottom of the page to view a list of Water Quality Limited Segments under Section 303(d) of the federal Clean Water Act, which requires states to identify waterbodies that do not meet water quality standards and are not supporting their beneficial uses. The list identifies the pollutant or stressor causing impairment, and establishes a schedule for developing a control plan to address the impairment.