Application of UV in North America and USEPA Guidance Manual for UV Disinfection

The USEPA has issued a proposed version of the LT2ESWTR which includes information on the use of ultraviolet (UV) radiation for the inactivation of Cryptosporidium, and a draft Guidance Manual to provide the US with direction on the proper installation and operation of UV disinfection systems. The final versions of these documents are expected to be published in 2005. Still, utilities have been installing or making plans to install UV disinfection systems. This technology holds great promise to provide sufficient protection against pathogens to meet the latest round of regulations, but hurdles remain to be overcome to ensure proper design and operation. One of these involves validating the UV dose under certain operating conditions. To address this issue, a procedure is proposed for either performing the validation tests at the utility’s water treatment plant or having them conducted by third parties.