Assessing the Impact of CYA
The Effect of CYA on Disinfection
The following table shows the HOCl concentration with various levels of CYA and FC (pH 7.5, 77 °F):
- Probability of infection as described in the paper, per-visit risk (Πv)
- 1 illness in x number of swimmers ( x = 1/ Πv)
- Potential number of illnesses per year based on the estimated value of 301 million swimmer visits per year (illnesses per year = 301,000,000/x)
- Prevent swimmers from peeing or pooping in the pool since the sources of many recreational water illnesses (E. coli, Giardia, Cryptosporidium) are from the people in the pool.
- Promote showering before entering the water so that any germs adhering to swimmers can get rinsed down the drain instead of into the pool.
- Maintain a residual sanitizer in all parts of the pool at all times
- Maximize the efficacy of your sanitizer by using the least amount of CYA stabilizer that you need to maintain
**The paper and supplemental materials are available for free from this web site: https://www.mdpi.com/2073-4441/11/6/1314 . The model is in a Microsoft Excel workbook and anyone can download the model and perform their own calculations with scenarios tailored to their specific pool.
*** Throughout this article, all of the default values for the model input parameters were used, unless noted otherwise. **** https://www.cdc.gov/healthywater/swimming/fast-facts.html