AWWA ACE93159

The Seattle Water Department, realizing the potential problem that chlorine gas can present in densely populated areas, decided to switch to sodium hypochlorite. A full-scale operational prototype was used at one test reservoir. Operators kept notes on day-to-day operations and performance. These notes were used to guide the predesign phase of the new facilities. Based on the prototype, problems were identified, including general problems associated with a corrosive product (pipe leaks, pump failure, storage problems), formation of chlorate ion, building chemical handling and feeding facilities on site without interrupting service or offending customers who use the reservoirs for recreation, and operation and maintenance scheduling and training. The basic components of the sodium hypochlorite disinfection system include chemical storage and containment; dilution, mixing, and transfer; feed and delivery; and instrumentation, including metering pumps and control valves. Each of these is described, with emphasis on solving the design problems. Metering pump and control valve options were evaluated and compared based on technical feasibility and operating characteristics, cost, and operators' opinion of the equipment; each of these criteria are discussed.

Product Details

Published:

01/01/1993

ISBN(s):

0898677149

Number of Pages:

15

File Size:

1 file , 610 KB