Contract: $2,248,540

Team Members
Owner: City of Hagerstown Water Department
Engineer: Gannett Fleming, Inc.
General Contractor: Johnston Construction Comapany

Key Accomplishments:

• Johnston completely rebuilt all ten existing water filters including piping and controls and staged the rebuilding of the water filters in order to keep the plant in operation at required capacity at all times during construction.
  

JCC was the remedial general contractor that led the rebuilding of the filtering section of the R.C. Willson Phase II Improvement Water Treatment Plant project. The facility is a 20 mgd potable water treatment plant provides drinking water to the City of Hagerstown, Williamsport, Smithsburg, and the surrounding areas.

Project sequencing required the plant to be kept in operation at capacity except for a few shutdowns for tie-ins lasting from two to six hours in duration. Only one or two filters were taken out of service at any given time. Work included demolishing existing filter equipment; raising concrete filter box walls; installing new underdrains, media and washwater troughs; piping modifications in pipe gallery; installing air blowers; constructing a washwater standpipe; installing prepurchased instrumentation equipment; and all related electrical work.

Project access was through windows as the existing structure could not handle any overhead pick points. Demolition was extremely difficult due to access, odor and dust control, and exceptionally hard concrete to demolish. All of the plant’s filter boxes were demolished and rebuilt. Most of the filter piping was modified and insulated. Pipe modifications were often difficult because old valves would not shut off completely. In addition, an existing 90,000 gallon backwash storage tank was demolished and replaced with a 200,000 gallon welded steel storage tank. Finally, the plant was fully automated with the installation of a computerized instrumentation package.

The project was started in March 1997 and was completed on time in December 1998.