ES&S was the prime consultant for the planning and design of two new gravity sewer projects to relieve existing sewers that serve some of the City’s oldest neighborhoods and the downtown central business district (CBD). The project was initiated due to a combination of aging pipe infrastructure, some dating back to the early 1900s, and capacity constraints due to increased development activities in the downtown area, particularly much denser residential properties that are under construction or planned in the next several years. Project #1 replaces three outfall sewers (15”-21” diameter) that roughly parallel the MKT Trail. These lines were replaced with approximately 6000-LF of new gravity sewer, ranging in size from 8-inch to 42-inch diameter pipe. A comprehensive alignment study was conducted to balance impacts to trail access, adjacent trees and vegetation, stream water quality, and corridor property owners.
Project #3 replaced and upsized older, existing sewer with 2900-LF of new 6”-18” diameter gravity sewer, mostly located in the street ROW along the south edge of the CBD. Due to the potential impacts on downtown businesses and traffic access, the design allowed bids for both open-cut and trenchless installation options, especially where the sewer replacement was upsizing existing pipe under Elm Street running along the south side of downtown Columbia and adjacent to the University of Missouri campus. Project #3 design was led by subconsultant, HDR Engineering.