Big Dry Creek Lift Station, Force Main, & Interceptor Project

This project involved the planning, design, and construction of an 8.1 MGD (expandable to 16.2 MGD) submersible lift station with four 200-HP pumps, new 16-inch dual force mains, and a 27-inch interceptor sewer.

Project services included an alternative station configuration evaluation; force main alignment analysis; service area study; design and construction phase services; Colorado Department of Public Health & Environment (CDPHE) approvals; USACE 404 permitting; coordination with CDOT, Adams County, and RTD; and preparation of a storm water management plan.

Providence was responsible for evaluating station layout configurations along with an alignment alternatives analysis involving the relocation of the City’s 5-mile, Big Dry Creek Force Main as part of the redesign of one of the City’s largest lift stations. The force main alternatives analysis examined three potential routes for conveying future flows to the Todd Creek sewerage basin for ultimate delivery to Metro Wastewater District’s (MWRD) northern Wastewater Treatment Plant (WWTP). Analyses also included property / right-of-way research, utility investigations, cost estimating, constructability, operational considerations, and land use impacts. In addition to the installation of dual 16-inch force mains, the project involved the installation of a 24- to 27-inch interceptor sewer.

The project’s planning and design phases involved detailed hydraulic evaluations involving separating flows into a dual-chambered lift station and the ability to direct flows into single or dual force mains. Subsurface conditions at the lift station site required detailed structural design of a deep concrete wet well founded on drilled piers to mitigate impacts of high ground water and expansive soils. Major project elements included: 4 new submersible solids handling pumps and motors (200 Hp), a deep dual-chambered cast-in-place concrete wet well, a new onsite diesel generator and automatic transfer switch, an emergency overflow structure, pigging stations for force main cleaning, alarm telemetry integration through the City’s existing SCADA system, 2.4 miles of dual 16-inch force mains, 1.6 miles of 24- to 27-inch gravity interceptor sewer, force main discharge structures, and force main to sewer junction box, four road crossings (2 Open Cut – Holly St., Ulster St; 2 tunneled – State Highway 7, Quebec Street), and parallel installation along State Highway 7 (CDOT) and Yosemite Street (Adams County).