ABC ABC Regulatory Compliance and Safety 2 — Questions and Answers
Question 1: What is the required minimum free chlorine residual in a water distribution system under most US state regulations?
- 0.2 mg/L (Correct answer)
- 0.5 mg/L
- 1.0 mg/L
- 2.0 mg/L
Correct answer: 0.2 mg/L
Most states require a minimum free chlorine residual of 0.2 mg/L at any point in the distribution system to prevent microbial regrowth.
Question 2: What type of hazard is represented by confined spaces in water treatment facilities?
- Permit-required confined space hazard (Correct answer)
- Open-space oxygen hazard
- Chemical burn hazard only
- Electrical arc flash hazard
Correct answer: Permit-required confined space hazard
Tanks, vaults, and manholes at water facilities are typically permit-required confined spaces due to hazards like oxygen deficiency and toxic atmospheres.
Question 3: Under the Lead and Copper Rule, action must be taken if lead levels exceed the action level at what percentage of tap samples?
- 10% (Correct answer)
- 5%
- 15%
- 25%
Correct answer: 10%
If lead exceeds 15 ppb at more than 10% of tap water samples (90th percentile), the system must take action under the Lead and Copper Rule.
Question 4: What is the primary purpose of the Consumer Confidence Report (CCR) that water systems must issue annually?
- Inform customers about water quality and sources (Correct answer)
- Report violations to the EPA
- Document operator certification status
- Summarize capital improvement spending
Correct answer: Inform customers about water quality and sources
The CCR is an annual water quality report that community water systems must deliver to customers, detailing source water and contaminant levels.
Question 5: Which personal protective equipment is mandatory when handling gaseous chlorine at a water treatment plant?
- Self-contained breathing apparatus (SCBA) (Correct answer)
- Dust mask
- Safety glasses only
- Chemical-resistant gloves only
Correct answer: Self-contained breathing apparatus (SCBA)
SCBA is required when working with or near gaseous chlorine because it is a toxic gas that can be fatal even at low concentrations.
Question 6: Which federal rule establishes treatment technique requirements for Giardia and viruses in surface water systems?
- Surface Water Treatment Rule (Correct answer)
- Total Coliform Rule
- Disinfectants and Disinfection Byproducts Rule
- Groundwater Rule
Correct answer: Surface Water Treatment Rule
The Surface Water Treatment Rule requires filtration and disinfection for surface water systems to achieve specific log-removal credits for Giardia and viruses.
ABC ABC Regulatory Compliance and Safety 2
What is the required minimum free chlorine residual in a water distribution system under most US state regulations?