How long must a pool close if liquid fecal matter is present?

When liquid fecal matter is present in a pool, closing it for 13 hours is necessary to ensure the thorough disinfection of the water. This duration allows for the appropriate sanitation measures to be taken, particularly the application of chlorine or other disinfectants, to effectively kill any harmful bacteria or pathogens that may have been introduced.

The Centers for Disease Control and Prevention (CDC) recommend a specific timeframe for closing a pool based on the type of contamination. In the case of a fecal incident, especially when liquid feces are involved, the pool must remain closed for a substantial amount of time to ensure that the water is safe for future swimmers. During this timeframe, the pool operator can properly treat the water, conduct necessary cleaning, and then retest the water quality before reopening.

Other potential durations mentioned, such as 1 hour, 2 hours, and 6 hours, would not be sufficient for adequate sanitation in cases of liquid fecal contamination, which requires rigorous measures to ensure the safety of all patrons. Thus, the recommendation of closing the pool for 13 hours is deemed necessary to uphold safety standards.