AWWA WQTC71631

Metro Vancouver (MV) owns and operates the Coquitlam Water Treatment Facility(CWTF), which has a rated capacity of 1,200 ML/day (317 MGD) and treats water fromCoquitlam Lake, one of the regions' three water supply sources. This gravity-fedunfiltered supply is currently treated by a process train that includes ozone and chlorinefor disinfection and soda ash for corrosion control. Under the Coquitlam UV DisinfectionProject, a new ultraviolet (UV) disinfection facility will provide a multi-barrier,sequential ozone-UV-chlorine disinfection strategy. Under this strategy, ozone willprovide disinfection for 4-log virus inactivation and oxidation for improved UVtransmittance (clarity) of the raw water and disinfection by-product (DBP) precursorreduction, UV will provide disinfection for 3-log Cryptosporidium and Giardiainactivation, and chlorine will provide disinfection to maintain a secondary chlorineresidual in the distribution system. In addition, ozone will provide 3-log Giardiainactivation as a back-up disinfection barrier to UV, and chlorine will provide up to 2-logvirus inactivation as a back-up disinfection barrier to ozone. This paper presents the results of the basis of design phase of the Coquitlam UVDisinfection Project. It includes a discussion of process design criteria, UV equipmentselection, UV facility layout alternatives and results of the Basis of Design DecisionWorkshop. It also presents a discussion of hydraulic issues associated with the VPLsystem, including results of a physical model laboratory study undertaken to optimizeinlet hydraulics to the individual UV units. Includes 5 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

18

File Size:

1 file , 1.9 MB