The Association of Pool & Spa Professionals has released the new edition of its commercial water-quality standard, called ANSI/APSP/ICC-11 2019 Standard for Water Quality in Public Pools and Spas.

While this year’s changes have been largely editorial and aimed at aligning the standard with the Model Aquatic Health Code (MAHC) and others, the committee that writes and updates APSP-11 has already begun laying groundwork for the next edition, which is expected to address larger issues.

This year’s edition includes a section about secondary and supplemental disinfection systems, as they are increasingly included in the design of commercial pools and aquatics facilities.

Some changes were made to make the standard consistent with the MAHC. This comes as part of an effort between APSP and the Council for the Model Aquatic Health Code to align their language.

Perhaps the most significant changes for this most recent edition include adjustments to bromine and chlorine levels. APSP-11 now says that pools treated with bromine must have a minimum residual of 2.0 parts per million, up from 1.0 ppm. For spas, the minimum bromine residual has increased from 2.0 to 4.0 ppm.

This change brings bromine levels in line with the total oxidation of free available chlorine levels specified in the standard, said John Weber, a member of APSP’s Recreational Water Quality Committee (RWQC) and a senior formulations chemist for KIK Custom Products, the parent company to BioLab.

The writers have also changed the maximum levels for combined chlorine. For pools, this parameter was increased from 0.2 ppm to 0.4 ppm. In spas, maximum combined chlorine levels were reduced from 0.5 ppm to 0.4 ppm. These measurements bring APSP-11 in line with the Model Aquatic Health Code, Weber said.

The levels for free available chlorine (FAC) have remained the same, however the standard now specifically stipulates the cyanuric acid (CYA) conditions that necessitate these parameters. For instance, pools with more than 50 ppm of CYA must have at least 2.0 ppm of FAC. Spas with the same CYA levels must have 3.0 ppm FAC.

The writers also expanded the definition section to address venues and issues in the commercial pool world, such as aquatic venue, increased-risk aquatic venue, interactive water play venue, secondary disinfection system, substantial alteration, therapy pool and wading pool.

In the near future, the RWQC will begin working on the next edition. APSP standards generally are updated about every five years, said Carvin DiGiovanni, APSP’s vice president of technical and standards.

The RWQC is expected to tackle some larger issues in the next version. The group likely will look to expand the use of secondary disinfection for public pools, Weber said. “Right now, it’s only required on high-risk venues, but there’s some talk about recommending them for all public facilities to help control potential cryptosporidium outbreaks,” he said.

The writers have also may re-examine the practice of break-point chlorination and whether it’s still the most appropriate way to address high combined chlorine levels. “Maybe we can limit the amount of chlorine needed to break the combined chlorine,” he said.

Finally, the topic of cyanuric acid levels may garner more exploration.

The next version will likely involve representatives from the Environmental Protection Agency to help make sure that APSP-11 falls in line with the Federal Insecticide Fungicide and Rodenticide Act (FIFRA). Writers will probably do more to make the standard consistent with the MAHC, DiGiovanni said.