Welcome to the State of California 

EDT Library and Water Quality Analyses Data and Download Page

NOTE: On July 1, 2014, the Drinking Water Program transferred from CDPH to the State Water Resources Control Board (SWRCB). Find out more at http://www.waterboards.ca.gov/drinking_water/programs/index.shtml.


Last Update: August 28, 2014 

This page contains the Electronic Data Transfer (EDT) Library, a link to Schedules for Upcoming Water Quality Monitoring,  and files for the Division of Drinking Water's water quality analyses database, and county small water system water quality data files.

EDT Library

These executable self-extracting files* support the submittal of drinking water analytical results.  More information is available at the Drinking Water Program's EDT webpage

Write-On for Windows 95/98/2000/XP Water Quality Software Upgrade (Version 2.0r) (Zip file, expands to 4.0MB)Opens in new window. — Last Update: September 15, 2011. 

This zip file contains WO2SETUP.EXE, ~4.5 MB, the setup file for Write-On for Windows 95/98/2000/XP Water Quality Input System (Version 2.0r). The file can be installed directly into an existing Write-On folder, and the changes will be made automatically.  The entire installed Write-On for Windows 95/98/2000/XP software will require ~14.5 Mb of disk space with the Library installation.  


Water System and Source Libraries (Zip file, expands to 6MB)Opens in new window. — Last Update: August 28, 2014 

This zip file contains 148 files to be copied into the Write-On directory, \WOWIN2 and extract to replace the existing files. It is to be used with both DOS and Windows versions of Write-On software. It includes large and small water system and source libraries, and an updated laboratory data file, "lab.dat," used by Write-On.

List of Water Quality Chemicals and Parameters (Excel)Opens in new window.— Last Update: March 5, 2013 

This is an MS Excel file (~70 kB) that lists chemicals in Write-On, and includes US EPA STORET numbers or other identifiers, maximum contaminant levels, detection levels for purposes of reporting, and reporting units.

Hardcopy Reporting Forms (Zip) Opens in new window. — Last Update: September 15, 2011

This file, FORMS.ZIP, 67 kB, is self-extracting (expanding to 657 kB) and includes the following forms in MS Word: (1) Base Neutral and Acids, (2) Organic Chemical Analysis, (3) Radioactivity Analysis, and (4) General Mineral, Physical & Inorganic Chemical Analyses.  NOTE: These forms are for hardcopy submission of water quality data only (prior to the requirement for EDT submittal) and not for the required submittal of data by EDT.  

Write-On Library Mover (Zip)Opens in new window. — Last Update:  March 25, 2003

This zip file contains the Write-On Library Mover (LIBMOVE.EXE) is a utility that assists you in moving updated system and source libraries to your hard disk drive.  It is ~15 kB in size.  This file saves you the task of having to reenter the sources and systems you created to the new libraries with Library Maintenance. This file was formerly included with the Water System and Source Libraries (ALL_LIB.EXE).  Included is a Library Mover.doc 03/25/2003

*Obtain a copy of these files by clicking on the highlighted text to download a self-extracting version of these files. After successful download, simply double click on the file in your File Manager and the extraction process will be performed. 




Schedules of Upcoming Monitoring 

CDPH's drinking water quality monitoring notification documents identify upcoming required contaminant testing of drinking water for water systems in California.  They  are updated periodically to reflect changes in the database.

Monitoring Schedules 


California Department of Public Health Water Quality Analyses Database Files

The following historical water quality analyses data are available to download and are divided among four .dbf files (Chemical.zip, Chemhist.zip, Chemarch.zip and Chemxarc.zip), four supporting data files (Siteloc.zip, Watsys.zip, Lab.zip, and Storet.zip), and one Word file that provides explanation. 

It is recommended you use WinZip software program to extract the downloaded water quality data files if you receive an error message using any other program.

NOTE:  The zipped files must be copied to your drive and expanded.  After expansion, the .DBF file can be imported into most well know database software programs, such as Microsoft Access, Fox Pro, or Paradox.  Note that spreadsheet programs such as Excel are not able to import all of the records in the database and should not be used to prepare reports.

NOTICE TO USERS OF THE DATABASE:  Users of this database should use care in interpreting these data.  For example, a single detection of a contaminant may not indicate contamination.  CDPH would not consider a single detection of a contaminant, if unconfirmed with a follow-up detection, to be an actual finding.  As another example, the presence of a contaminant in raw water at a given concentration does not necessarily mean that the water was served by the water system to its customers, or, if served, that the contaminant was present at that concentration.  Water systems may not use certain sources or may treat or blend them prior to service.

Questions about contaminants in particular sources are best addressed by the specific public water system, or by the DHS district office. 


Drinking water analyses reported directly from laboratories – Last Update August 18, 2014

  • CHEMICAL.ZIP contains chemical data from January 1, 2011 through this month
  • CHEMHIST.ZIP contains chemical data from January 1, 2006 through December 31, 2010
  • CHEMARCH.ZIP contains chemical data from January 1, 2000 through December 31, 2005
  • CHEMXARC.ZIP contains chemical data from April 1974 through December 31, 1999 


Supporting database files – Last Update August 18, 2014

  • Drinking Water Source identification number (PS Code), name and type (SITELOC.DBF)
  • Water Systems identification number, name, and address (WATSYS.DBF)
  • Laboratories reporting water quality analyses (LAB.DBF)
  • Chemical (Storet) Reported (STORET.DBF)
  • Word file WQM Documentation.doc provides additional description and explanation of the individual files available for downloading – Last Update July 19, 2013


County Small Water Systems Water Quality Analyses Data Files (CSV files)

The data files were last updated on August 26, 2014.  The file County Small Water Systems Data File Heading Definitions (Excel)Opens in new window.provides an explanation and description of the Small Water Systems data fields presented below.

Alpine County District 32

Inyo County District 44


Napa County District 58


San Diego County District 67 

Tehama County District 82


Amador County District 33

Kings County District 46


Nevada County District 59


San Joaquin County District 69


Tulare County District 84


Butte County District 34

Los Angeles County District 49


Placer County District 61


San Luis Obispo County District 70


Tuolumne County District 85

Calaveras County District 35

Madera County District 50


Plumas County District 62


Santa Barbara County District 72


Yolo County District 87


Contra Costa County District 37

Merced County District 54


Riverside County District 63


Santa Cruz County District 74


Yuba County District 88


El Dorado County District 39

Mono County District 56 


Sacramento County District 64

Shasta County District 75



Imperial County District 43

Monterey County District 57


San Bernardino County District 66


Stanislaus County District 80



Schedules of Upcoming Monitoring
Additional Information for Laboratories
Information about Chemicals and Contaminants
Last modified on: 9/4/2014 3:13 PM