Big Bend Left Abutment Collector Pipe System

Big Bend Left Abutment Collector Pipe System, Fort Thompson, South Dakota. 

The U.S. Army Corps of Engineers (USACE), Omaha District NWO, intends to pursue an award for the replacement of the Left Abutment Collector Pipe System located at the Big Bend Dam in Fort Thompson, South Dakota.  The work covered in this section is outlined as a statement of construction requirements common to all the work. Specific requirements for materials and installations are provided under the Technical Sections herewith. No claims for extras shall be made on account of items presumed to have been omitted from this section. The work includes but not limited to the removal and replacement of the existing left abutment collector pipe system located on the the downstream left abutment of Big Bend Dam. The left abutment collector pipe system consists of the existing toe drain pipe, toe drain outfall, relief well collector, and relief well casing outfalls. Work to include extending the relief well collector into the relief well channel and backfilled. Six (6) existing wells are to be abandoned (RW-66, RW-66A, RW-67, RW-68, RW-68A, RW-68B) and piezometer (OW20-02) as part of this contract. Abandonment or removal of existing relief well casing outfalls as indicated on the contract drawings. The new left abutment collector pipe system will connect existing wells (RW-66B and RW-67A) and six (6) replacement relief wells (RW-66R, RW-66AR, RW-67R, RW-68R, RW-68AR, RW-68BR). The six (6) replacement relief wells will be installed by USACE prior to Contractor mobilizing to the site. Installation of four new manholes and two risers are a part of this contract. Extension of 24" CMP Culvert A and 24" RCP storm drain. A rip rapped apron will be constructed at the new relief collector pipe outfall location of the left abutment collector pipe system. 

Proposals are due on or before 19 September 2022 by 1200 PM CT.