Main street sewer project update in Plattsmouth. The new plan varies from what was tentatively proposed as a solution two weeks ago and the cost is a little lower.
The Cassgram reports that before the October 4th Plattsmouth City Council meeting that areas of the cobblestone walls of the two storm sewers under Main Street are leaning inward and stones are dislodging. (archives 10/6/10) The eventual collapse of the walls in some areas is a concern. The engineer recommended storm sewer replacement as part of the Main Street Corridor Improvement Project, a project that includes a new sanitary sewer and the streetscape improvements.
Filling the north storm sewer box and piping over to a new 66-inch south pipe was originally thought to be best solution. However, HDR engineer Chris Koenig found conflicts with gas and water mains and the new sanitary sewer. The height of the bigger pipe also posed a problem.
His new recommendation, approved by the city council Monday, contains a combination of 42-inch flexible pipe and 48-inch concrete pipe sections.