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TO: Mayor Richard C. Irvin
FROM: David E. Schumacher, P.E.; Superintendent of Water Production
DATE: July 15, 2021
SUBJECT:
A Resolution Authorizing an Addendum to the Amended and Restated Potable Water Service Agreement with Calgon Carbon Corporation (Calgon) for the continued lease of Granular Activated Carbon (GAC) in filter groups 1 - 4, 5 - 8, and 9 - 12 for the Water Production Division.
PURPOSE:
To obtain City Council approval for an addendum to the subject agreement for pricing and installation of GAC for filters 1 - 4 in 2021, filters 5 - 8 in 2022, and filters 9 - 12 in 2023 at the City of Aurora Water Treatment Plant (WTP).
BACKGROUND:
The Water Treatment Plant (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 on the GAC in the filter bed. Over time the GAC is expended (spent) and needs to be replaced/refreshed, typically between 36 - 42 months. This is done on a staggered basis for the three groups of filters listed above.
The Water Production Division (WPD) has standardized the use of specific GAC, Calgon F-300, as its primary filtration media due to its long-term (20+ years) successful and proven performance. F-300 can be considered a sole source product due to its attributes as a domestic, bituminous coal source and a specific manufacturing method referred to as reagglomeration which produces a high activity, durable, granular product capable of withstanding abrasion associated with repeated backwashing, hydraulic transport, and reactivation for reuse. Spent GAC is reactivated via a high-temperature heating process which volatilizes the adsorbed compounds thus returning the used GAC to additional productive service. Calgon's program for the turnkey service of supplying reactivated GAC is the Custom Municipal Reactivation (CMR) program. The addendum shows pricing option...
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