C-44 Seepage Management Exhibits for Sources Sought.pdf

This document is a technical design specification for relief well and outfall system infrastructure, prepared by the US Army Corps of Engineers for the Dam Safety Program.

The relief well design specifies construction of wells with 10-inch diameter stainless steel pipe to a total depth of approximately 50-60 feet below ground surface. Key design parameters include: constant top of riser elevation; constant top of grout with minimum 3-foot thickness (variable by location); constant bentonite thickness; continuous wire wrap stainless steel screens with uniformly graded quartz sand filter pack; and welded stainless steel plates to plug well bottoms. Well screen and filter pack dimensions vary by individual well location. The outfall system design includes protection of relief wells within 48-inch concrete manholes with 12-inch HDPE pipe conveying water to the Water Resources Planning and Coordination (WRPC) facility. Pipe invert elevations remain constant, though distances from relief wells to WRPC vary. Supporting infrastructure includes manhole depths varying 4-10 feet and pipe lengths ranging 25-40 feet, with geotextile and gravel materials specified throughout. The system incorporates non-shrink grout and maintains minimum 2-foot clearance from slope and outfall intersection points, with discharge elevation approximately 2 feet above EDD (Exceptional Discharge Design) flows.