What is the regulatory definition of a cross-connection in a water supply? A physical connection between a public water system and any source of water or other substance that may lead to contamination of the water provided by the __________ through backflow.

• A. PWS
• B. POTW
• C. Municipal System
• D. Water Utility

Answer: (A)

The main idea is that a cross-connection is any physical link between a public water system and another source that could contaminate the water because of backflow. The missing term should identify the system being protected, which is the public water system, abbreviated PWS. So the completed idea is that the cross-connection is a link that could contaminate the water provided by the PWS through backflow. The other options don’t fit because POTW refers to wastewater treatment, and municipal system or water utility are generic terms, not the formal regulatory designation used in this definition. Backflow occurs when pressure changes cause water to flow backward, pulling in contaminants from the connected source into the drinking water system.