TO: Mayor Thomas J. Weisner
FROM: David E. Schumacher, P.E.; Superintendent of Water Production
DATE: November 5, 2013
SUBJECT: title
Resolution Authorizing the Execution of an Amended and Restated Potable Water Service Agreement with Calgon Carbon Corporation for the Continued Lease of Granular Activated Carbon for the Water Production Division.
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PURPOSE:
To obtain City Council approval for the execution of an Amended and Restated Potable Water Service Agreement with Calgon Carbon Corporation (Calgon), Pittsburgh, PA, for the Continued Lease of Granular Activated Carbon (GAC) at the City of Aurora Water Treatment Plant (WTP) to include pricing options for the use of both virgin and reactivated GAC.
BACKGROUND:
The WTP has 12 dual-media filters which contain sand and GAC which are used to remove solids prior to disinfection of the water. In addition, the GAC media serves to remove taste and odor compounds which are adsorbed onto the GAC which remains in the filter. Over time the GAC is expended (spent) and needs to be replaced/refreshed, typically between 36 and 42 months. This is done on a staggered schedule in three groups of filters, filters 1 - 4, 5 - 8, and 9 - 12.
The Water Production Division (WPD) currently leases GAC under an existing agreement with Calgon. Historically, the WPD has always utilized brand new GAC, otherwise known as "virgin" GAC. Due to escalating costs of virgin GAC, Calgon has provided an option to utilize "reactivated" GAC under their Custom Municipal Reactivation (CMR) program. Reactivation, in simple terms, is the high temperature heating of the spent GAC which volatilizes the adsorbed compounds thus returning the GAC to additional productive service. Reactivated carbon has been utilized in the potable water treatment industry for many years and is widely accepted for use in different treatment applications. The opportunity for cost savings from utilization of reactivated GAC is significant without sa...
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