Time to Get Dirty?

This article discusses a project conducted in 2006 by the Eklutna Water Treatment Facility in Anchorage, Alaska, to add media to its filters. The plant, put online in 1988 with standard multimedia filters of gravel, sand, and anthracite coal, has eight filters, each approximately 600 ft 2 . Media loss was discovered in 1995 and at that time all of the anthracite, contained in 50‐lb bags, was dumped into the filters by hand. Subsequently, the surface wash pressure during the backwash cycle was modified to prevent further loss of filter media. The article discusses the recent filter renewal project which involved loading 200,000 lbs of anthracite by hand. Subsequent scenarios to deal with loading the coal are described, with the optimum solution being that of inventing a new device, “Swirl‐o‐Matic,” the Cadillac of filter media dispensers that cut the bag dump time down from 20 minutes to about 6 minutes.