Las Vegas · Commercial pool & spa · Bio-hazard responseLas Vegas · Bio-hazard response
Everyone out.
Then call.
Feces, vomit or blood in a commercial pool or spa. Clear the water, and every pool on the same filter. Then tell us what you found.
Feces, vomit or blood in the water. Clear the water, and every pool on the same filter. Then tell us what you found.
Four incidents, as the CDC treats them
Formed
Unstabilized chlorine to 2 ppm free, pH 7.5 or less, held 25 to 30 minutes with the filter running.
Diarrhea
Hyperchlorinated for Crypto: 20 ppm for 12.75 hours with no stabilizer, 28 hours with stabilizer at 15 ppm or less; above that, part-drain first. Then a backwash to waste.
Vomit
Free chlorine at 2 ppm, pH 7.5 or less, for 30 minutes. The germ of concern is norovirus.
Blood
Chlorine kills the germs found in blood. Some operators still treat it as vomit.
What happens
CDC's steps, in order.
Bio-hazard response is part of our closure work: we diagnose the issue and put the corrective steps in place. The health district's rules come first.
- 01
Close
Swimmers out, from every pool that shares the filter.
- 02
Remove
Take it out with a net or a bucket and dispose of it. Never vacuum it.
- 03
Disinfect
Raise free chlorine and hold it, pH 7.5 or less, for the time that incident needs.
- 04
Filter
Keep the filtration running the whole time the chlorine is held.
- 05
Reopen
Swimmers back only when chlorine and pH sit inside the range the health district allows.
The log
Written down before it reopens
CDC asks operators to log every fecal incident, and to finish the entry before swimmers go back in.
- When
Date and time of the incident.
- What
Formed stool, or diarrhea.
- At the time
Free chlorine and pH when it was seen.
- Response
How chlorine and pH were adjusted.
- Held
Free chlorine, pH and the disinfection time.
Questions
What operators ask
Do we have to close for blood?
Not by CDC's reckoning. Chlorine kills the germs found in blood, CDC knows of no one infected by blood in a pool, and it sees no public health reason to treat blood like vomit. Operators who choose to anyway close the pool, net it out and hold 2 ppm free chlorine, pH 7.5 or less, for 30 minutes. The health district's rules come first.
Can we vacuum it out?
No. CDC's guidance is to take it out with a net or a bucket and dispose of it in a sanitary way. Vacuuming fecal matter from the water is not recommended.
Why does diarrhea close a pool so much longer?
The parasite of concern, Crypto, is extremely chlorine-tolerant. With no stabilizer in the water, CDC's figure is 20 ppm free chlorine for 12.75 hours. With cyanuric acid at 1 to 15 ppm it is 20 ppm for 28 hours; above 15 ppm, the pool is partly drained first.
Whose rules apply?
CDC's steps do not replace state or local rules. For a Las Vegas commercial pool that is the Southern Nevada Health District, and its rules come first.
Do you handle bio-hazard response?
Yes. Bio-hazard response is part of our closure work for commercial pools and spas. Closed for another reason?
Tell us what you found.
Which water, what it was, and the last chlorine and pH reading.