South Lake Tahoe, CA (April 16, 2026) –  The South Tahoe Public Utility District (STPUD) announces an important update to its water system construction standards: stop and waste valves (“stop and drains”) on new construction projects can no longer be buried. This change is being implemented to reduce the risk of cross-contamination and to further protect the safety of the community’s drinking water.

STPUD is responsible for ensuring that the public drinking water system remains safe from contamination and pollution. A key component of this responsibility is the District’s Cross-Connection Control and Backflow Prevention Program, which identifies potential hazards and ensures that customers have proper backflow protection in place. This program aligns with California regulations and the State Water Resources Control Board’s Cross-Connection Control Policy Handbook. It includes hazard assessments, approved backflow devices, annual testing, and ongoing system oversight.

A cross-connection is any actual or potential connection between a potable (drinking) water supply and a source that could introduce contamination. Common examples include irrigation systems, fire sprinkler systems, boilers, chemical feed equipment, auxiliary water supplies, and buried stop and waste valves. When these connections are not properly managed, contaminants can enter the drinking water system, especially during backflow events.

Backflow occurs when water flows in the reverse direction, allowing non-potable water, chemicals, or other substances to enter the public water system. This can happen due to back siphonage, when system pressure drops and pulls water backward, or backpressure, when customer-side pressure exceeds system pressure and pushes water back into the supply.

Buried stop and waste valves present a unique risk because they can become submerged in soil or groundwater that may contain contaminants. During a backflow event, these contaminants can be drawn directly into the potable water system. By requiring that these valves remain above ground and properly protected, STPUD is reducing the likelihood of contamination and improving overall system safety.

“Protecting the quality of our drinking water is our highest priority,” said Paul Hughes, General Manager. “This update reflects our continued commitment to proactive measures that safeguard public health and align with state regulations.”

STPUD encourages contractors, developers, and property owners to familiarize themselves with the updated requirements and to work with District staff during project planning and construction. STPUD will be hosting a Contractor Workshop on Wednesday, April 29, 2026 from 4:00pm – 5:00pm to discuss changes to stop and drain installation standards and sewer lateral updates. Contractors are invited to attend this free workshop in STPUD’s Board Room at 1275 Meadow Crest Drive, South Lake Tahoe.

For more information about the Cross-Connection Control and Backflow Prevention Program, please visit www.stpud.us/cross-connection-backflow-program or contact Ross Cole, Inspections Supervisor at rcole@stpud.us.