PC Environmental & Hazard Management 3 — Questions and Answers
Question 1: Which type of backflow preventer is required on a connection to a high-hazard cross-connection such as a chemical feed line?
- Pressure vacuum breaker
- Double check valve assembly
- Reduced pressure zone (RPZ) assembly (Correct answer)
- Atmospheric vacuum breaker
Correct answer: Reduced pressure zone (RPZ) assembly
An RPZ (reduced pressure zone) assembly provides the highest level of backflow protection and is required for high-hazard cross-connections.
Question 2: What is the purpose of a grease trap in a commercial kitchen's plumbing system?
- Prevent hot water from scalding dishwashers
- Intercept fats, oils, and grease before they enter the sewer (Correct answer)
- Filter food particles from the drain water
- Reduce water pressure to the dishwasher
Correct answer: Intercept fats, oils, and grease before they enter the sewer
Grease traps capture fats, oils, and grease (FOG) to prevent sewer clogs and environmental contamination.
Question 3: When trenching near underground utilities, which minimum safe distance should a plumber maintain before hand-digging?
- 6 inches
- 18 inches (Correct answer)
- 24 inches
- 36 inches
Correct answer: 18 inches
Excavation within 18 inches of a marked utility line must be done by hand to avoid striking the utility.
Question 4: What does the term 'air gap' refer to in plumbing backflow prevention?
- A space between pipe insulation layers
- A vertical separation between a water outlet and flood level rim (Correct answer)
- A gap in the pipe threads to allow pressure relief
- An air pocket trapped in a supply line
Correct answer: A vertical separation between a water outlet and flood level rim
An air gap is the unobstructed vertical distance between the water supply outlet and the flood level of a fixture, preventing backflow by physical separation.
Question 5: Which regulation requires plumbers to notify the local water authority before making connections to a public water main?
- Clean Air Act
- Clean Water Act cross-connection control programs (Correct answer)
- Resource Conservation and Recovery Act
- National Environmental Policy Act
Correct answer: Clean Water Act cross-connection control programs
Cross-connection control programs under the Safe Drinking Water Act and Clean Water Act require notification before connections to public water mains.
Question 6: A plumber is replacing a toilet in a home built before 1978. What hazardous material should be assumed present in the surrounding materials?
- Asbestos and lead paint (Correct answer)
- Radon and formaldehyde
- Mercury and PCBs
- Benzene and ammonia
Correct answer: Asbestos and lead paint
Homes built before 1978 commonly contain lead-based paint and potentially asbestos in pipe insulation, flooring, and joint compounds.
Question 7: What is the correct method for disposing of old mercury-containing float switches removed from a water tank?
- Place in regular trash
- Take to a household hazardous waste facility (Correct answer)
- Flush down the drain
- Bury in the backyard
Correct answer: Take to a household hazardous waste facility
Mercury is a hazardous substance and must be disposed of at a certified household hazardous waste collection facility, not in regular trash or drains.
PC Environmental & Hazard Management 3
Which type of backflow preventer is required on a connection to a high-hazard cross-connection such as a chemical feed line?