Recent Changes to Cross-Connection Control

Author: Environmental Health Staff
Date: 8/29/2024 1:01 PM

A cross-connection is an interconnection between a potable water supply and a non-potable source via any actual or potential connection or structural arrangement between a public water system (PWS) and any source or distribution system containing liquid, gas, or other substances not from an approved water supply.

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The presence of a cross-connection represents a location in a distribution system through which backflow of contaminants or pollutants can occur. Backflow is the undesired or unintended reversal of flow of water and/or other liquids, gases, or other substances into a PWS’s distribution system or approved water supply. Normally, water from the public water system flows only one way, into a water user’s premises. When backflow occurs, water from the consumer’s premises can be pushed or pulled into the distribution system. If that water has been contaminated because of activities on the consumer’s premises (for example, the use of chemicals for plating/etching metals, the addition of corrosion inhibitors to industrial boilers and piping, or fire suppression systems with chemical additives), the water can carry contaminants into the distribution system, possibly causing illness or even death. Public water systems are required by State law to have programs in place to detect cross-connections and prevent backflow.

The State of California recently made the most significant changes to the regulations since the 1980s by adopting the Cross-Connection Control Policy Handbook (CCCPH) on July 1, 2024. The primary objective of the CCCPH is the protection of public health through the establishment of standards intended to ensure that PWSs and their drinking water distribution systems will not be subject to backflow. The possibility of illness and disease occurring by means of unprotected cross-connections has been well established; the need to prevent cross-connections with auxiliary water supplies or contaminant sources was identified over 100 years ago. The risk posed by backflow can be mitigated through preventive and corrective measures. To protect our drinking water quality and prevent the spread of infectious disease and other contaminants, mechanical backflow prevention assemblies are utilized to prevent used, unclean or contaminated water or substances from entering the potable/domestic water system. To prevent contamination, it may be necessary to install testable backflow prevention assemblies to prevent backflow from occurring. In San Luis Obispo County, these assemblies must be tested every year by a backflow tester certified by an approved accrediting agency. The CCCPH and its standards apply to all California PWSs, as defined in California’s Health and Safety Code (CHSC, section 116275 (h)). Compliance with the CCCPH is mandatory for all California PWSs. In addition, the State Water Resources Control Board (State Water Board) intends to build a foundation of awareness within the regulated community regarding the importance of backflow protection and cross-connection control.

The County of San Luis Obispo Environmental Health Services division works with over two dozen PWSs to abate cross-connections and prevent backflow. In the coming months, your water purveyor may reach out to you to learn more about how you use your water. For instance, do you have a dedicated irrigation system, or do you have a fire sprinkler system? Your water system may also mail out flyers to educate consumers on backflow prevention and its role in protecting public health. These outreach efforts are part of the CCCPH requirement to inform consumers about the importance of cross-connection control and backflow prevention. Your cooperation with these outreach efforts is critical to the protection of public health and is greatly appreciated.

Cross-Connection Control Policy Handbook (CCCPH) | State Water Resources Control Board (ca.gov)