Pool Fouling Guidelines

Niagara Region Public Health advocates following the U.S. Centers for Disease Control and Prevention Guidelines regarding faecal contamination.

The guidelines concentrate on the deactivation of the germ Cryptosporidium. Cryptosporidium is a treatment resistant, waterborne pathogen or germ.

A formed stool presents less of a risk for disease transmission as it acts as a container for the pathogens. As a result, the guidelines distinguish two separate approaches for pool disinfection - a formed stool and a liquid stool (diarrhea).

We have also included our recommendations for contamination by blood and vomit.

Fecal Contamination

There are some important healthy swimming habits:

  • A bather with diarrhea should not enter the pool
  • A bather should not swallow the pool water
  • A bather shall shower with soap and warm water before entering or re-entering the pool
  • All faecal accidents are to be reported to pool staff
  • Allow children to take bathroom breaks
  • Always wash hands after using the bathroom

Formed Stool

  • Clear the pool of all bathers and close the pool to the public. Do not allow anyone to enter the pool until the disinfection process is completed
  • If you have multiple pools that use the same filter, all pools will have to be closed
  • Leave the filter in operation and remove the faecal material with a net or scoop and dispose of it in a sanitary manner
  • Thoroughly clean the net or scoop to ensure all visible matter is removed. Disinfect the net or scoop by immersing in pool during disinfection
  • If necessary, clean the pool and deck surfaces and sanitize with an adequate disinfectant solution (i.e. chlorine solution of at least 50 ppm free available chlorine
  • Raise the FAC level to > 2ppm and ensure the pH is between 7.2 - 7.5. FAC residual is to be checked at least 3 points in the pool
  • Close the pool for an additional 25 minutes
  • Once the pool is reopened for bathers, document the incident and details on the daily pool record sheet

Diarrhea

  • Clear the pool of all bathers and close the pool to the public. Do not allow anyone to enter the pool until the disinfection process is completed
  • If you have multiple pools that use the same filter, all pools will have to be closed
  • Leave the filter in operation. Remove as much of the faecal material as possible with a net or scoop and dispose of it in a sanitary manner (do not vacuum the stool out)
  • Thoroughly clean the net or scoop to ensure all visible matter is removed. Disinfect the net or scoop by immersing in pool during disinfection
  • If necessary, clean the pool and deck surfaces and sanitize with an adequate disinfectant solution (i.e. chlorine solution of at least 50 ppm FAC)
  • If necessary, before attempting the hyperchlorination of any pool, consult an aquatics professional to determine the feasibility, the most optimal and practical methods, and needed safety considerations
  • Raise the free chlorine concentration to 20 ppm and maintain pH 7.5 or less and a temperature at 77°F (25°C) or higher. The free chlorine and pH should remain at these levels for at least 12.75 hours to achieve the CT inactivation value of 15,300. Crypto CT inactivation values are based on killing 99.9 percent of Crypto. This level of Crypto inactivation cannot be reached in the presence of 50 ppm chlorine stabilizer, even after 24 hours at 40 ppm free chlorine, pH 6.5 and a temperature of 77°F (25°C). Extrapolation of these data suggest it would take approximately 30 hours to kill 99.9 percent of Crypto in the presence of 50 ppm or less cyanuric acid, 40 ppm free chlorine, pH 6.5, and a temperature of 77°F (25°C) or higher
  • Confirm that the filtration system is operating while the water reaches, and is maintained, at the proper chlorine level for disinfection
  • Backwash the filter after reaching the CT inactivation value. Be sure the effluent is discharged directly to waste. Do not return the backwash through the filter. Where appropriate, replace the filter media (for diatomaceous filter)
  • Allow swimmers back into the water only after the required CT inactivation value has been achieved and the free chlorine and pH levels have been returned to the normal operating range as specified in the Public Pools Regulation
  • Document the incident and details on the daily pool record sheet

Vomit

Vomiting while swimming appears to be a common event. Often, vomiting is a result of swallowing too much water and, therefore, the vomit is probably not infectious. However, if the contents of the stomach are vomited, the same guidelines apply as for a formed stool:

  • Clear the pool of all bathers and close the pool to the public. Do not allow anyone to enter the pool(s) until the disinfection process is completed
  • If you have multiple pools that use the same filter, all pools will have to be closed
  • Leave the filter in operation and remove as much of the vomit material as possible with a net or scoop and dispose of it in a sanitary manner
  • Thoroughly clean the net or scoop to ensure all visible matter is removed. Disinfect the net or scoop by immersing in pool during disinfection
  • If necessary, clean the pool and deck surfaces and sanitize with an adequate disinfectant solution (i.e. chlorine solution of at least 50 ppm FAC)

Blood

Germs from blood are not transmitted to bathers through pool water. There is no public health reason to recommend closing the pool after a blood spill in properly disinfected pool water.

An operator may choose to do so to alleviate public fears and should then use the opportunity to check pool chemical levels. Document the incident on the daily pool record sheet.


Page Feedback Did you find what you were looking for today?