BAT BAT Cross-Connection Control & Risk Assessment 2 — Questions and Answers
Question 1: What is a 'direct cross-connection'?
- A cross-connection that only exists under certain pressure conditions
- A physical link that continuously connects the potable system to a contaminant source (Correct answer)
- A connection protected by a single check valve
- A cross-connection located outside the building
Correct answer: A physical link that continuously connects the potable system to a contaminant source
A direct cross-connection is a permanent physical link between the potable supply and a non-potable source, posing a continuous backflow risk regardless of operating conditions.
Question 2: Which condition is most likely to cause backsiphonage in a distribution system?
- High demand from an industrial booster pump downstream
- A water main break creating negative pressure in the supply line (Correct answer)
- A broken check valve in an RPZ assembly
- Thermal expansion in a closed system
Correct answer: A water main break creating negative pressure in the supply line
A water main break can create a sudden vacuum or negative pressure, pulling water backward from connected premises and causing backsiphonage.
Question 3: Which backflow preventer is typically used for low-hazard (non-health) cross-connections under continuous pressure?
- Reduced pressure zone assembly (RPZ)
- Double check valve assembly (DCVA) (Correct answer)
- Atmospheric vacuum breaker (AVB)
- Air gap
Correct answer: Double check valve assembly (DCVA)
A DCVA is approved for low-hazard applications such as lawn irrigation without fertilizer injection, providing protection against both backsiphonage and back pressure.
Question 4: What is 'premise isolation' in a cross-connection control program?
- Shutting off water service to a hazardous facility
- Installing a backflow preventer at the point of service entry to protect the public main from the entire facility (Correct answer)
- Isolating individual fixtures within a building with local backflow preventers
- A survey method to identify all cross-connections on a property
Correct answer: Installing a backflow preventer at the point of service entry to protect the public main from the entire facility
Premise isolation places a backflow preventer at the meter or service entry to protect the distribution system from any hazards that may exist anywhere within the entire premises.
Question 5: What is the primary goal of a cross-connection control survey?
- To test all existing backflow prevention assemblies for compliance
- To identify all actual and potential cross-connections and assess the appropriate level of protection needed (Correct answer)
- To count the number of backflow preventers installed at a facility
- To verify pipe material compliance with plumbing codes
Correct answer: To identify all actual and potential cross-connections and assess the appropriate level of protection needed
A cross-connection control survey systematically identifies every location where contaminants could enter the potable supply and evaluates whether adequate protection exists.
Question 6: Which federal agency establishes drinking water quality standards that underpin cross-connection control programs in the US?
- Occupational Safety and Health Administration (OSHA)
- Environmental Protection Agency (EPA) (Correct answer)
- Department of Transportation (DOT)
- Centers for Disease Control (CDC)
Correct answer: Environmental Protection Agency (EPA)
The EPA establishes National Primary Drinking Water Regulations under the Safe Drinking Water Act, which require water suppliers to protect against contamination including cross-connections.
BAT BAT Cross-Connection Control & Risk Assessment 2
What is a 'direct cross-connection'?