What Is a Cross-Connection?

A cross-connection is any actual or potential connection between the public drinking water system and a source of non-potable water or other substances.

Common examples include:

• Irrigation systems connected to a home’s plumbing
• Hose attachments used for mixing pesticides or fertilizer
• Pools, spas, and decorative fountains
• Auxiliary water supplies (wells, recycled water, etc.)

If backflow occurs—meaning water flows in the opposite direction—these connections can allow contaminants to enter the drinking water system. Cross-connection control helps prevent this from happening.

Click Here for a Cross-Connection FAQ:

Why Is Cross-Connection Control Required?

The State of California requires all public water systems to implement a Cross-Connection Control Program to protect public health. These requirements are mandated under:

• California Code of Regulations, Title 17
• State Water Resources Control Board Drinking Water Program

Water suppliers must identify potential risks, ensure proper backflow prevention devices are installed and maintained, and document program compliance. These rules help ensure the community’s water remains safe, reliable, and free from contamination.

HydroCorp Conducting Required Property Risk Assessments

To meet updated State mandates, the Town has contracted with HydroCorp, a certified cross-connection control specialist. HydroCorp will be conducting the required on-site cross-connection and backflow risk assessments for properties throughout Discovery Bay.

• HydroCorp will contact each customer directly to schedule their assessment.
• Assessments are required by State regulations to identify any potential risks and ensure protective measures are in place.
• Residents may be asked questions about irrigation systems, pools, hose connections, or other water-use equipment on their property.

We appreciate your cooperation when HydroCorp reaches out; these assessments are a critical part of ensuring ongoing water safety for the entire community.

Updates to the Town’s Ordinance

To comply with updated State requirements and align with industry best practices, the Town of Discovery Bay has amended Ordinance No. 7 – Water Regulations and Service Ordinance.

The revisions clarify requirements for:

• Cross-connection control
• Backflow prevention device installation
• Annual testing and certification
• Enforcement provisions for noncompliance

These updates ensure the Town remains in full regulatory compliance and maintains the highest standards of water quality protection.

Have Questions? We’re Here to Help

For residents and contractors who would like more information, the Town has prepared a detailed FAQ document, available here:

Protecting our community’s drinking water is a shared responsibility. If you have questions about backflow devices, irrigation systems, or whether your property may require cross-connection protection, please contact us.

📞 Phone: (925) 634-1131
🏛️ Town of Discovery Bay – Water & Wastewater Services Department