HIC Pool & Recreational Water Safety 2 — Questions and Answers
Question 1: What is the minimum required turnover rate for a public swimming pool under most state health codes?
- Every 2 hours
- Every 6 hours (Correct answer)
- Every 8 hours
- Every 12 hours
Correct answer: Every 6 hours
Most state codes require public pool water to turn over (be fully recirculated and filtered) at least once every 6 hours.
Question 2: A health inspector finds cyanuric acid levels at 120 ppm in an outdoor pool. What action is required?
- No action; 120 ppm is within safe range
- Dilute the pool water to lower the level (Correct answer)
- Add more chlorine to compensate
- Close the pool immediately for algae treatment
Correct answer: Dilute the pool water to lower the level
Cyanuric acid above 100 ppm reduces chlorine effectiveness significantly; the corrective action is to partially drain and refill to dilute the stabilizer.
Question 3: Which enteric pathogen is most commonly associated with recreational water illness (RWI) outbreaks in treated swimming pools?
- Legionella pneumophila
- Cryptosporidium parvum (Correct answer)
- Giardia lamblia
- E. coli O157:H7
Correct answer: Cryptosporidium parvum
Cryptosporidium is the leading cause of RWI outbreaks in treated pools because its oocysts are highly chlorine-resistant.
Question 4: Under the Virginia Graeme Baker Pool and Spa Safety Act, what is required on all public pool main drains?
- Anti-entrapment drain covers meeting ANSI/ASME A112.19.8 (Correct answer)
- A guard rail within 12 inches of the drain
- A warning sign posted within 10 feet
- A minimum water depth of 4 feet above the drain
Correct answer: Anti-entrapment drain covers meeting ANSI/ASME A112.19.8
The VGB Act mandates anti-entrapment drain covers that meet the ANSI/ASME A112.19.8 standard to prevent suction entrapment injuries.
Question 5: What is the recommended pH range for pool water to optimize chlorine disinfection efficiency?
- 6.0–6.5
- 7.2–7.8 (Correct answer)
- 8.0–8.5
- 8.5–9.0
Correct answer: 7.2–7.8
A pH of 7.2–7.8 keeps hypochlorous acid (the active sanitizing form) at effective concentrations while minimizing irritation.
Question 6: A spa pool is found to have water temperature at 106°F. What is the inspector's correct response?
- Issue a warning but allow continued operation
- Require immediate closure until temperature is reduced (Correct answer)
- Allow operation only for adults over 18
- Require a posted sign warning of elevated temperature
Correct answer: Require immediate closure until temperature is reduced
Most health codes prohibit spa water temperatures above 104°F due to risk of hyperthermia; 106°F requires immediate closure.
Question 7: Which chemical combination creates a potentially dangerous chlorine gas reaction when used in pools?
- Sodium hypochlorite mixed with calcium carbonate
- Trichlor tablets mixed with calcium hypochlorite (Correct answer)
- Sodium bicarbonate mixed with muriatic acid
- Cyanuric acid mixed with sodium bicarbonate
Correct answer: Trichlor tablets mixed with calcium hypochlorite
Mixing trichlor (acidic) with calcium hypochlorite (alkaline/oxidizing) can cause a violent reaction producing chlorine gas and fire.
HIC Pool & Recreational Water Safety 2
What is the minimum required turnover rate for a public swimming pool under most state health codes?