AWWA WQTC58819

Ultraviolet light disinfection provides great promise for utilities that will need to meet the Cryptosporidium inactivation requirements of the Long Term 2 Enhanced Surface water Treatment Rule. Ultraviolet disinfection is very effective against both Giardia and Cryptosporidium as well as other microbiological pathogens. The technology is compact, inexpensive and easy to operate. Theory suggests that ultraviolet disinfection does not promote the formation of disinfection byproducts or impart enough energy to the water to create new types of disinfection byproducts; however, there had not been a study conducted within the United States to determine if there are unanticipated affects resulting from ultraviolet disinfection of water on the long term quality of the water in the distribution system. The Massachusetts Water Resources Authority (MWRA) and the Town of Concord, Massachusetts in coordination with the Southern Nevada Water Authority (SNWA), and the Portland Water Bureau, through an American Water Works Research Foundation (AwwaRF) Tailored Collaboration Project are evaluating the effectiveness of ozone followed by medium-pressure ultraviolet light (MP-UV) and of medium-pressure UV alone for disinfection of unfiltered source water and distributed water quality. This research will determine: disinfection effectiveness (log inactivations) of Giardia, Cryptosporidium and human enteric viruses, particularly in cold water; and, synergistic impacts on disinfection byproduct formation, biostability, corrosion control, and red water. Includes 2 references, tables, figures.