Cya regulations

[amin36]

i guys
I am trying to find regulations for using Cyanuric acid in outdoor swimming pools

Curently my main field of work is just on Residential pools not Commercial/Public pools.

When it comes to CYA everything is fine until we get to Cryptosporidium.

I studied the pages below

This one from CDC

Cleaning and Remediation | Healthy Swimming | Healthy Water | CDC

It says:

"For public pools, the pool operator should raise the free chlorine concentration very high for hours if someone has diarrhea in the pool since it might contain the chlorine tolerant parasite Cryptosporidium. This recommendation does not apply to residential pools. Members of one family or the same household are less likely to spread Cryptosporidium to each other if they use the same pool. Additionally, raising the free chlorine concentration very high for hours increases the risk of pool chemical injuries to residential pool owners (for example, respiratory distress or chemical burns) if the pool chemicals are mishandled. This means it is very important for swimmers to follow the steps of healthy swimming whether they use public or residential pools"

And this one from a TFP expert:

Cryptosporidium - Further Reading

And he says:

"Generally speaking, I wouldn't worry about Crypto in a residential pool. As for what commercial/public pools can do, they are in a tough position. There currently is no method they can use that will clear the pool of Crypto in any reasonable timeframe"

They both say that one should not concern about crypto in a residential outdoor pool.

So my question is:

Does an accidental diarrhea /fecal accident in a residential pool should be avoided?

I mean should I ignore Crypto or Giardia in a residential outdoor swimming pool?

Thanks

 

[ajw22]

This thread says...

Response to Cryptosporidium Post

This thread is in response to this post. Yes, you are correct, though the CDC link I gave said 20 ppm FC for at least 12.75 hours, but amounts to the same thing (and the chart they show has 10 ppm FC for 25.5 hours similar to your calculation). The problem is that these are CT values WITHOUT...

www.troublefreepool.com

The filtration using a flocculant/coagulant to capture the oocysts in the filter and then backwashing to remove them will probably work to some extent but it's unclear as to the precise level of reduction that would be achieved. Even if there were 100% removal for passing through the filter in this situation, it still takes multiple turnovers since one turnover only filters 63% of the water, two turnovers filters 86%, three turnovers filters 95%, four turnovers filters 98%, five turnovers filters 99%, and it takes almost 7 turnovers to filter 99.9%. And this all assumed perfect mixing and circulation while in reality actual numbers are lower.

Ozone and UV systems are effective at killing Crypto, but have the same issues of needing good circulation and multiple turnovers. Since a relatively small amount of chlorine dioxide will kill Crypto in the bulk pool water overnight, I think that a periodic (weekly?) dosing would at least limit the exposure time if there are undetected fecal accidents and would also be viable after a known fecal accident and for pools that have CYA without resorting to excessive superchlorination. Unfortunately, there doesn't seem to be any manufacturer willing to step up to pay for the studies to get EPA approvals for this nor to do some studies to make sure it doesn't cause more problems than it solves.