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What is a Cross-Connection? 

A "cross-connection" is an unprotected actual or potential connection between a potable water system (water that is safe for drinking) and any source or system containing water or other substance that is not safe, wholesome, and fit for human consumption (examples include a cooling system or irrigation system.) 
Backflow testing is a process that is used to test your plumbing system to make sure that drinking water is not being contaminated by dirty water or chemicals infiltrating the water supply. 

What is the Inspection Process? 

The Environmental Health Division conducts cross-connection control inspections within water users' premises and at recycled water use areas to ensure that the drinking water supply is not connected to potential sources of contamination.  To report a suspected or known cross connection please call us at (714) 433-6280 or email us at

Click here for a list of Cross Connection Control Specialists for water agencies in Orange County 

Orange County Backflow Prevention Tester Guidelines and Tester Registration 

Coming Soon: The Orange County Health Care Agency is in the process of updating its backflow tester program. This initiative comes in response to the recent modifications in standards and legislation regarding backflow prevention outlined in the newly released Cross Connection Control Policy Handbook by the State Water Resources Control Board of California. For your reference, a copy of this handbook is available here.

Quick Links:


Tester Registration Requirements

New Applicants: 

To complete the HCA registration / application process:

  1. Download and complete the Backflow Tester Application and Backflow Tester Code of Conduct.
  2. In a single PDF document, email a copy of your ANSI Certification (e.g. AWWA, etc.), your completed and signed Backflow Tester Application, Backflow Tester Code of Conduct, proof of your backflow test kit calibration and a passport size photo to:
  3. Type your first and last name (and your existing OC tester number if applicable) on the email subject line.
Current Orange County Backflow Prevention Assembly tester expiring July 1, 2024 and beyond

If you already have a current Backflow Assembly Testing Certification from an ANSI accredited organization:

  1. Complete the HCA registration / application process
  2. Once processed, your new HCA backflow assembly tester registration will be aligned with the expiration date from the Certifying Organization

If you do not have a current Backflow Assembly Testing Certification from an ANSI accredited organization:

  1. Obtain a certification from an ANSI accredited Certifying Organization (e.g. AWWA, etc.)
  2. Complete the HCA registration / application process
  3. Once processed, your new HCA backflow device tester registration will be aligned with the expiration date from the Certifying Organization.

OC Health Care Agency backflow tester registered applicants are responsible for maintaining the continuous validity of all necessary licenses and certificates. Failure to keep these credentials current may lead to the invalidation of their HCA backflow device tester registration. Incomplete applications will not be processed.

Compliance: Agreement to comply with the most recent Code of Conduct adopted by Environmental Health and the Orange County Cross Connection Control Group.

Contact Information Updates: Testers are responsible for promptly informing HCA-EH about any changes in their contact information. Contact (714) 433-6000 or email for updates.

Licensing and Compliance Requirements

A State contractor's license is not mandatory to be a registered tester. However, testers must ensure compliance with State and local laws and regulations regarding necessary business licenses, contractor's licenses, insurance, etc.

Different water suppliers have specific guidelines and additional requirements for backflow prevention testing. It is crucial for testers to communicate directly with the water suppliers to ensure compliance with their individual regulations. Click here for a list of Cross Connection Control Specialists for water agencies in Orange County 


Equipment Maintenance and Backflow Assembly Test Reporting

Test Kit Maintenance: Testers are responsible for maintaining their test kits in good repair, calibrating them yearly, and conducting repairs as needed.

Report Submission:

  • All backflow assembly test reports must be submitted to HCA-EH and the water supplier within 10 days of the initial test, regardless of the result.
  • Reports must be submitted individually by location on approved forms as PDF attachments
  • The name of the water supplier must be typed correctly into the subject
  • The PDF report must be saved as: OC Registration # - assembly address
  • Reports are only accepted via email to


Orange County Published Backflow Tester List

Tester List: Registered backflow testers may opt for inclusion in a published listing exclusively on HCA's website. The listing is organized by city based on tester seniority to assist businesses in locating testers in their area.
Click Here for the Backflow Prevention Device Tester List


Violations and Disciplinary Actions

Suspension or Revocation: The Orange County Health Officer, or his designee, may suspend, revoke, or refuse to renew a tester's registration upon finding fraud, deception, gross negligence, misconduct or violation of the Orange County's Code of Conduct for Backflow Prevention Testers after an administrative hearing. Suspensions or referrals will be reported and referred to the ANSI accredited Certifying Organization.

Public Records Act Requests: Suspension, revocation and test reports are subject to disclosure per The California Public Records Act found in the California Government Code, beginning at Section 6250. Records subject to inspection and copying include any writings, meaning any handwriting, typewriting, printing, photostating, photographing, and every other means of recording upon any form of communication or representation, including information available in an electronic format.

Legal Consequences: Violations of Health and Safety Code Sections 116800-116820 or may lead to misdemeanor complaints or disciplinary actions. Knowingly filing a false test report may be a misdemeanor offense.