As of February 1, the Salt Lake County Health Department began closing public swimming pools in the county that do not meet Utah’s new interlock safety requirements.

By January 30, 163 of the county’s 649 year-round and winter seasonal pools were not compliant, meaning that about one quarter of Salt Lake County’s pools were subject to closure.

The new rule, which went into effect on January 31, requires interlocking layers of protection for circulation and chemical feed systems. Electrical interlocking the pool’s chemical feed system with its circulation system prevents chemicals from continuing to dispense (and build up dangerously in the system) if the water circulation system stops functioning. A buildup of pool chemicals (chlorine and muriatic acid) can create chlorine gas, which may cause illness, lung damage and—in extreme cases— death.

The new rule was prompted by numerous such incidents that take place throughout the country, and one in particular.

In June of 2019, the Veterans Memorial Pool in Pleasant Grove, Utah, experienced an equipment malfunction that led to a buildup of chemicals that sickened dozens of patrons and sent several to the hospital. To help prevent similar incidents, in August of 2020 the state of Utah updated its pool rule, R392302, to require all public pools to interlock their chemical feed systems with their water circulation systems by January 31, 2023.

For more than a year, the Salt Lake County Health Department has provided all county pools with multiple reminders of the state’s new requirement and its compliance deadline.

The health department estimates that most pools can become compliant for a one-time cost of $500 or less; a pool company or a licensed electrician may perform the necessary electrical work. Newly constructed pools should meet requirements automatically, as interlock is now an industrywide safety standard.

Throughout February, the health department was focusing on enforcement of pools that operate year-round and seasonally in the winter. In early spring, inspectors will begin enforcement of pools that operate seasonally in the summer— an additional 641 pools.

In Utah, a public pool is any pool open to the public or that serves four or more residential housing units. This includes pools at apartment and condo communities, recreation and fitness centers, hotels, and schools. Pools that serve three or fewer housing units, including private backyard pools, are not subject to public health regulations.

At press time, 14 pools had been closed for critical violations.