Development and characterization of nonpathogenic surrogates for UV reactor validation

• Published in: Journal - American Water Works Association Vol. 99; no. 3; pp. 73 - 82
• Main Authors: FALLON, KRISTEN S., HARGY, THOMAS M., MACKEY, ERIN D., WRIGHT, HAROLD B., CLANCY, JENNIFFR L.
• Format: Journal Article
• Language: English
• Published: Denver American Water Works Association 01.03.2007
• Subjects: Acids; Bacteria; Bacteriophages; Bias; Bioassays; Cryptosporidium; Disinfection; Disinfection & disinfectants; Dosage; Dose response relationship; Drinking water; Groundwater; Microorganisms; Morphology; Pathogens; Potable water; Reactors; Reduction; regulatory issues; Responses; RNA; Studies; Surface water; Ultraviolet Disinfection; Ultraviolet radiation; Viruses; Wavelengths; United States > US
• ISSN: 0003-150X; 1551-8833
• DOI: 10.1002/j.1551-8833.2007.tb07890.x

Ultraviolet (UV) light for disinfection of drinking water is garnering increased attention because of its ability to inactivate Cryptosporidium at low UV doses. In the United States, reactors are validated using coliphage MS2 as the challenge surrogate; however, MS2 is significantly more UV‐resistant than Cryptosporidium, a regulated pathogen targeted for UV inactivation credit. This study characterized the UV dose‐response of microorganisms that more closely match the dose‐response of Cryptosporidium than does MS2. Dose‐responses of several bacteriophages were determined. The stability of phages in groundwaters in the presence and absence of three UV absorbers was examined. The UV dose‐responses of phages T7 and SP8 were similar to that of Cryptosporidium; β was more resistant than Cryptosporidium but less so than MS2. Some water matrixes had a negative effect on the survivability or recoverability of phages; this effect was amplified or negated with the addition of UV absorbers.