The US carbon dioxide (CO2) shortage is continuing to impact industries across the country, with San Diego officials on Saturday (20th August) announcing the closure of four city pools due to CO2 supply issues.

Earlier this month, gasworld reported that a tightening in CO2 supply was continuing to hit businesses across the US, with strains set to continue throughout the coming months as a result of contamination issues and planned plant closures.

Read more: US CO2 shortage: Strains set to continue throughout the coming months

In the instance of the San Diego pools, CO2 is used to help balance and maintain the pH levels in the pool water. As explained by Air Products, in water, CO2 forms a mild carbonic acid that helps maintain alkalinity and reduce total dissolved solids. It form a natural bicarbonate buffer, which minimises peaks and troughs of pH[1].

That being said, as a CO2 replacement during the shortage, maintenance crews will continually apply muriatic acid, a common chemical used in backyard pools, as a safe alternative and will be regularly monitoring each pool to ensure pH levels are safe for the public.

gasworld understands that four municipal pools will be temporarily closed as a result of the shortage. San Diego officials, however, have said they will work diligently to keep the other nine pools open.

In the meantime, the city will continue to see alternative sources of CO2. Until that point, there is no definitive timetable for when the closed pools will reopen.