Us CDC (center disease control) and residential pools

[beautifulpool]

Since in 2016, CDC (US Center for Disease Control) mandated CYA levels be maintained no higher than 15ppm -in public pools (Im assuming they’re reasoning was wanting fast kill time for brown and yellow accidents in large public pools with young children) do families of younger kids ever factor that in when deciding their optimal CYA target?
Residential owners Can have as much CYA as we want if we maintain FC/CYA Ratio....but since cya lowers free chlorine’s ORP (bad) and slows and weakens chlorine’s kill ability, im not a huge CYA fan and prefer to keep my cya level under 30.
....and i heard two fellows in the industry call stabilizer “CYA - cover ur Axx” they mainly like it cause it extends their time between pool stops -if they service over 100 pools weekly....but it slows kill time

 

[JoyfulNoise]

The CDC Model Aquatic Health Code (MAHC) Committee has already moved towards a more rigorously science-based understanding of CYA. See this paper -

Assessing the Impact of Cyanuric Acid on Bather’s Risk of Gastrointestinal Illness at Swimming Pools

Current regulatory codes for swimming pool disinfection separately regulate free chlorine (FC) and cyanuric acid (CYA). It is well-known that CYA affects disinfection rates by reversibly binding to FC in aqueous solutions. However, limits for these regulated parameters have neither...

www.mdpi.com

The industry will always remain light-years behind the science as their motive isn’t health and well-being but profit.

 

[beautifulpool]

The CDC Model Aquatic Health Code (MAHC) Committee has already moved towards a more rigorously science-based understanding of CYA. See this paper -

Assessing the Impact of Cyanuric Acid on Bather’s Risk of Gastrointestinal Illness at Swimming Pools

Current regulatory codes for swimming pool disinfection separately regulate free chlorine (FC) and cyanuric acid (CYA). It is well-known that CYA affects disinfection rates by reversibly binding to FC in aqueous solutions. However, limits for these regulated parameters have neither...

www.mdpi.com

The industry will always remain light-years behind the science as their motive isn’t health and well-being but profit.

Thank you for the article. It’s fascinating how things work.

 

[Oly]

A maximum CYA/FC ratio of 20 is recommended because this simple value provides a modest reduction in infection risk from the currently allowed value of 45 without imposing major changes in pool operation and is based on consideration of CYA/FC ratios associated with relevant risk and pool operation scenarios.

Great study thanks for the link.

This gives me pause....... Additional information is also needed regarding rates of fecal sloughing and acceptable risk of infection at public swimming pools

 

[Andy49]

The final takeaway from the paper for me was the recommended ratio of 20:1 for CYA/FC. Excellent paper (not that I understood all the statistics and formulas)

 

[Andy49]

Just to add to the previous note, TFP method is more conservative and that is what I am following.