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TO: Mayor Richard C. Irvin
FROM: David E. Schumacher, P.E.; Superintendent of Water Production
DATE: July 9, 2018
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 5 - 8 and 9 - 12 for the Water Production Division (WPD).
PURPOSE:
To obtain City Council approval for an addendum to the subject agreement for pricing and installation of GAC for filters 5 - 8 in 2018 and for filters 9 - 12 in 2019 at the City of Aurora Water Treatment Plant (WTP).
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 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 schedule in three groups of filters, filters 1 - 4, 5 - 8, and 9 - 12.
The WPD has standardized the use of the Calgon F-300 GAC product line as its primary filtration media do 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 the abrasion associated with repeated backwashing, hydraulic transport, and reactivation for reuse. Recently, the WPD successfully tested and subsequently transitioned to utilizing reactivated GAC provided by Calgon under their Custom Municipal Reactivation (CMR) program. Spent GAC is reactivated via a high-temperature heating process which volatilizes the adsorbed compounds thus returning the used GAC to additional productive service. The cost savings from the u...
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