When a major fouling happens, specific steps must be taken to ensure that proper disinfection occurs.  This is necessary to reduce health risks associated with pool fouling, particularly those presented by cryptosporidium, a parasite found in diarrhea known to cause gastrointestinal illness.

 

A major pool fouling involes liquid stool (diarrhea).

 A closure is necessary to reduce health risks associated with pool fouling, particularly those presented by cryptosporidium, a parasite found in diarrhea known to cause gastrointestinal illness. 


The Lifesaving Society and public health provide public pool operators with the steps they should take in such situations.  These steps include raising the chlorine levels to 20 ppm (parts per million) and maintaining them at that level for a minimum of 13 hours. 


The pool can reopen once chemicals reach the levels mandated by Public Pool Regulation 565. This can be challenging to achieve. To expedite this, a portion of pool water needs to be drained — and fresh water added.