AWWA ACE61766

The City of Winnipeg completed an intensive Phase 2 pilot water treatment program in1997. The Phase 2 program tested the most suitable treatment processes for Winnipeg'swater quality on an annual cycle and resulted in a recommendation for a baseline watertreatment process, which included conventional dissolved air flotation (DAF).In November 2002, the use of high-rate DAF was identified as a potential cost savingsalternative for consideration by the City. In 2003, the City contracted a consultant teamfrom Earth Tech and CH2M HILL to determine the suitability and limits of the high-rateDAF process through pilot testing. The high-rate DAF pilot tests were completed inDecember 2003 and the suitability of high-rate DAF was determined by comparing theprocess performance with data from the Phase 2 testing. Based on the success of thehigh-rate DAF pilot trials, it was recommended that high-rate DAF be considered as aviable alternative to conventional DAF for the City's full scale Water Treatment Plant.In August 2004, the City contracted the consultant team to design the full scale watertreatment plant. The new treatment plant will use a multiple barrier approach that willfurther protect the public from waterborne diseases, improve the aesthetic quality of thewater and help it comply with current and anticipated Canadian Drinking Water QualityGuidelines and Provincial standards and regulations. High-rate DAF is a relatively newtechnology and there is currently only one manufacturer with significant full scale NorthAmerican experience (Infilco-Degremont's AquaDAF™ system). Only four full scaleAquaDAF™ systems existed worldwide at the time of the pilot testing. The AquaDAF™design is patented, and thus the full scale equipment procurement method represents akey component of the full scale design. A competitive tendering process betweenconventional and high-rate DAF incorporating detailed facility life cycle costing, as wellas non-economic evaluation criteria, was selected.Full scale DAF design optimization includes the flocculation time and mixing energies,flocculation aid chemical requirements, DAF design loading rate, mechanical floatremoval, DAF saturator design, recycle requirements, and the number and size of DAFbasins. The design plant flow is 400 ML/day, which will represent the largest DAFsystem in North America. If high-rate DAF is selected, the high-rate DAF design willrepresent the highest DAF loading rate (36 m/hr in warm water conditions) amongexisting full scale installations. The City of Winnipeg Water Treatment Plant is scheduledto be constructed and in operation by the end of 2007. Includes 2 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/17/2005

Number of Pages:

12

File Size:

1 file , 400 KB