Journeyman Plumber ExamWater Supply SystemsEasy
During a routine inspection, a plumber observes a cross-connection between a potable water supply line and a non-potable irrigation system at a commercial property. There is no backflow prevention device installed. What is the primary hazard associated with this condition?
- AIncreased water consumption by the irrigation system.
- BReduced water pressure in the potable water supply.
- CDamage to the irrigation system's pump.
- DContamination of the potable water supply.
Show answer & explanationAnswer & explanation
Correct answer: D. Contamination of the potable water supply.
A cross-connection between potable and non-potable sources, without proper backflow prevention, allows contaminated water from the non-potable source (like an irrigation system using reclaimed water or water with chemicals) to enter and pollute the safe drinking water supply, posing a significant health risk.
Why the other options are wrong
- A. Increased water consumption is unrelated to the cross-connection itself, but rather to the irrigation system's operation.
- B. While possible, reduced pressure is not the primary or most dangerous hazard of a cross-connection.
- C. Damage to the irrigation pump is not caused by a cross-connection; it's an issue with the pump's operation or installation.
Cross-Connection Hazard
The most significant danger posed by an unprotected cross-connection is the potential for non-potable (contaminated) water to enter and pollute the potable (drinking) water supply.
- Leads to public health risks.
- Requires immediate action and backflow prevention.
- Can occur due to backpressure or backsiphonage.
Memory trick: Crossed lines mean poisoned sips, protect the tap from dirty drips.