Welcome to the Department of Pesticide Regulation

Ground Water Protection Program
Well Inventory Report

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DPR is required by law to take specific actions to prevent further pesticide pollution of ground water. A key element is maintaining information that must be submitted by state and local agencies when they sample wells for pesticides. These agencies provide detailed information about the wells they sample. This includes the well number, well type, street address (for wells other than large system wells), chemical analyses performed, sample date, sample type (initial or confirmation), analysis date, sample concentration and minimum detection limit (in parts per billion), and laboratory information. Agencies also may send information about well construction or the source of the potential contamination.

DPR collects this information, checks it for accuracy, and enters it into our Well Inventory Database. DPR established this database in 1983 to compile reliable information on the occurrence of non-point source contamination of ground water and facilitate graphical and numerical analysis of the data. DPR has more than 1,600,000 records in the inventory, representing more than 22,000 wells. DPR uses this data to evaluate and guide our ground water protection monitoring and research activities. With some restrictions (described below), this sampling data is available - on request and has been used by academic institutions, governmental agencies, and members of the public.

Well Inventory Reports on Ground Water Testing for Pesticides:

State law was amended in 2004 to require DPR to post this report on its Web site. Previously, it was published on paper as well.


Policy on Release of Well Data Collected by the Department of Pesticide Regulation Concerning Wells Sampled for Pesticide Residue

In accordance with the provisions of the California Public Records Act (Government Code section 6250 et seq.) and the Information Practices Act of 1977 (Civil Code section 1798 et seq.), DPR cannot disclose the exact location of the wells that have been sampled or personal information about the well owners to the general public.

DPR can release specific well location information to another public agency provided the other public agency agrees, in writing, to protect the confidentiality of the information and documents released. Requestors must submit the written agreement before DPR will disclose the requested information.

Learn more about DPR’s Public Records Release guidelines.



For content questions contact:
Craig Nordmark
1001 I Street, P.O. Box 4015
Sacramento, CA 95812-4015
Phone: (916) 324-4138
E-mail: cnordmark@cdpr.ca.gov