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Response to Diarrhea (liquid) stool in a Pool/Spa

Diarrhea (liquid stool) in Pool/Spa

  1. Direct everyone to leave all pools into which water containing the feces is circulated. Do not allow anyone to enter the contaminated pool(s) until all decontamination procedures are completed.
  2. Remove as much of the fecal material as possible using a net or scoop and dispose of it in a sanitary manner. Clean and disinfect the net or scoop (e.g., after cleaning, leave the net or scoop immersed in the pool during disinfection). Vacuuming stool from the pool is not recommended *.
  3. Proper hyperchlorination utilizes a combination of concentration and time. This is expressed as a "CT" value. One other factor is whether the facility utilizes a chlorine stabilizer such as chlorinated isocyanurates. While these help maintain proper chlorine levels to combat most other contaminates, they actually hinder the chlorine's ability to combat Cryptosporidium.
    1. For Un-Stabilized pools, the CT value is 15,300. For example: If the operator maintains the Free Available Chlorine (FAC) at 1 ppm, then it must be maintained for 15,300 minutes or approximately 10.6 days. If the operator maintains the FAC at 10 ppm, then it must be maintained for 1,530 minutes or 25.5 hours. Lastly, if the operator maintains the FAC at 20 ppm , then it must be maintained for 12.75 hours.
    2. For pools which utilize a chlorine stabilizer, the first thing the operator must do is to bring the stabilizer concentration down below 50 ppm. Proper disinfection cannot take place in the presence of 50 ppm or greater concentrations of chlorine stabilizer. After the operator brings the stabilizer level below 50 ppm, a CT value of 72,000 is utilized. For example: If the operator maintains the FAC at 1 ppm, then it must be maintained for 72,000 minutes or approximately 50 days. If the operator maintains the FAC at 20 ppm, then it must be maintained for 3,600 minutes or 2.5 days. Lastly, if the operator maintains the FAC at 40 ppm, then it must be maintained for 30 hours.
  4. Insure that the filtration system is operating while the pool reaches and maintains the proper free available chlorine concentration during disinfection.
  5. Backwash the filter thoroughly after reaching the CT value. Be sure the effluent is discharged directly to waste and in accordance with state or local regulations. Do not return the backwash through the filter. Where appropriate, replace the filter media.
  6. Swimmers may be allowed into the pool after the required CT value has been achieved and the free available chlorine level has been returned to the normal operating range allowed by the state or local regulatory authority. Maintain the free available chlorine concentration and pH at standard operating levels based on state or local regulations. If necessary, consult state or local regulatory authorities for recommendations on bringing the free available chlorine levels back to an acceptable operating range.
  7. Establish a fecal accident log. Document each fecal accident by recording date and time of the event, formed stool or diarrhea, free available chlorine concentration at the time or observation of the event and before opening the pool, the pH, the procedures followed to respond to the fecal accident (including the process used to increase free chlorine residual if necessary), and the contact time.

* No uniform recommendations for disinfection of vacuum systems are available. However, if a vacuum system is accidentally used, the waste should be discharged directly to a sewer or other approved waste disposal system and not through the filtration system. The dilution effect of the pool water going through the hose may reduce the risk for high-level contamination of the vacuum system.

Many conventional test kits cannot measure free available chlorine levels this high. Use chlorine test strips that can measure free available chlorine in a range that includes 20mg/L (such as those used in the food industry) or make dilutions for use in a standard DPD (N, N-diethyl-p-phenylenediamine) test kit using chlorine-free water.

This information is based on the most current information provided by the Centers for Disease Control. The CDC provides pamphlet called Fecal Accident Response Recommendations for Pool Staff (pdf) which outlines the above along with other helpful information.

The Clayton County Board of Health has also put together a Fecal Incident Flow Chart (pdf) that can be used as a quick reference at a pool/spa location.


Clayton County Board of Health
Office of Environmental Health Services

1 Crown Center 1895 Phoenix Blvd, Suite 400 College Park, GA 30349
Phone: (678) 610-7469   Fax: (770) 603-4874