UV systems comply with guidelines for municipal water

The International Ultraviolet Association (IUVA) and the American Water Works Association (AWWA) working group have released a communication related to low-wavelength, medium-pressure disinfection. According to the document, legislators and engineers are now recommending the application of a correction factor for municipal drinking water medium-pressure UV systems to compensate for the effects of wavelengths less than 240 nm. Pathogen surrogates used for testing have proven to react differently than actual target pathogens to these low wavelengths. Therefore, previous validation testing and modelling may have overestimated inactivation of harmful target pathogens.

While Berson systems have always blocked wavelengths less than 240 nm with the use of type-240 quartz sleeves, users of similar medium-pressure systems not in compliance will be required to re-evaluate system sizing and possibly make costly modifications or purchase new equipment. Berson’s 240-type quartz sleeves also comply with DVGW (Germany) standards requiring low wavelength blockage to prevent nitrite formation.

Since the Low Wavelength Document was published, Berson has implemented a number of new medium-pressure UV system projects where owners are adding UV treatment for disinfection of cryptosporidium and giardia. Berson’s type-240 quartz sleeves are used in the company’s InLine+ medium-pressure, closed vessel UV disinfection system. The InLine+ is simple to install and features virtually maintenance-free operation with a standard automatic quartz sleeve wiping system and variable power ballast output. It is third-party validated and conforms to the DVGW standards, the USEPA drinking water guidelines, the NWRI re-use guidelines and also has NSF approval.