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The US Environmental Protection Agency has developed a validation protocol that is included as part of the recentlyreleased Draft Ultraviolet Disinfection Guidance Manual (UVDGM). As part of the DraftUVDGM, methodologies for validation test data analysis have also been proposed. Toreceive credit for Cryptosporidium, Giardia, or virus inactivation using UV disinfection, theLong Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) requires systems todemonstrate that the UV reactor can deliver the required dose through validation testing, aswell as determine a set of operating conditions that can be monitored by the control systemto ensure that the UV dose required for a given pathogen inactivation credit is deliveredduring operation. In this paper, the full-scale, on-site validation testing of the UV disinfectionsystem constructed at the water production plants operated by the Clayton County WaterAuthority (CCWA) is discussed.During the procurement phase for CCWA's UV disinfection equipment system, a site-specificvalidation testing protocol was developed by CH2M HILL in cooperation with theGeorgia Environmental Protection Division (GA EPD). From January through August, 2003,CCWA, CH2M HILL, and Wedeco-Ideal Horizons completed biodosimetry testing on-siteusing one UV reactor at each WPP. The validation testing conducted at each WPPconsisted of testing the installed low pressure reactor with seeded MS2 coliphage over thefull range of anticipated operating conditions including minimum to maximum flowrates,worst-case water quality (i.e, minimum UV transmittance), and simulated end of lamp life.Concurrent collimated beam testing was also conducted so that the "reduction equivalentdose" could be determined based on the bench results from testing and the level ofinactivation achieved at full-scale. Includes 4 references, tables, figures.

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Edition: Vol. - No. Published: 11/02/2003 Number of Pages: 12File Size: 1 file , 510 KB