AWWA ACE56169

This paper provides rationale for key assumptions and decisions made in developing the design for the ultraviolet (UV) disinfection system for the in-plant recycle stream treatment system at the East Bay Metropolitan Urban District (EBMUD) Walnut Creek Direct Filtration Water Treatment Plant (WTP). Results of the analysis are as follows: Cryptosporidium is the target pathogen for UV inactivation in the recycle stream; free-swimming pathogens are the basis of UV dose selection; and,design dose for the system is 40 mJ/cm2; acceptable UV systems have attributes that include validated UV dose and UV sensor response, closed-vessel configuration, andmechanical cleaning of quartz sleeves and UV sensor probes; UV transmittance of 85% (254 nm and 10 mm pathlength); approximate capital cost of $1.1 million for current conditions; and, approximate O&M cost of $0.06 per 1,000 gallon for current conditions. The purpose of this paper is to provide conceptual level layouts and cost estimates for ultraviolet (UV) disinfection for in-plant recycle streams. Specific components of this analysis and corresponding organization of this paper are as follows: establish disinfection goals and UV dose requirement; discuss attributes of acceptable UV systems; develop UV disinfection system configuration and layout; and,present estimates for capital and operational costs. The following are the general performance goals of the UV disinfection system: provide inactivation of Cryptosporidium and other chlorine-resistant pathogens in in-plant recycle streams; and,provide reliable UV equipment, systems, and operational strategies. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/16/2002

Number of Pages:

16

File Size:

1 file , 2.6 MB