East Gallatin River Riverside Force Main Horizontal Directional Drilling FWP-DN-FSH-R3-24-078

Nov 19, 2024 4:02 PM

The project involves constructing a new duplex sewer lift station equipped with two submersible pumps just west of Springhill Road off Elaine Lane. An adjacent building will house the process mechanical piping, controls, and an emergency generator. A six-inch high-density polyethylene (HDPE) force main will also be installed along Springhill Road, extending from the lift station to the City’s water reclamation facility. The length of pipeline is approximately 4,300’. To avoid impacting the bed and banks of the East Gallatin River, avoid removing mature trees, and to align the installation outside the current pavement of Springhill Road, several sections of the force main will be installed using HDD, including a small irrigation ditch off Elaine Lane, two crossings of Springhill Road, the East Gallatin River crossing, and the roadway entrance to Riverside Drive. All other sections will employ open-cut construction techniques. For the East Gallatin River crossing, the HDD will begin approximately 141’ north of the East Gallatin River and daylight approximately 238’ south of the river. The depth under the river for HDD and pipeline installation is 20 feet, as necessary to maintain adequate cover below maximum estimated scour depth.

The project is located at the northern extent of Bozeman, Montana, on Springhill Road and Elaine Lane. The area in the immediate vicinity of the East Gallatin River consists of riparian floodplain. The Riverside Country Club golf course and residential developments adjoin the river to the north. Natural habitat is primarily restricted to the riparian corridor of the East Gallatin River. Upland areas within the survey limits are primarily dominated by grasses, small shrubs, and weeds, including smooth brome (Bromus inermis), western wheatgrass (Elymus smithii), Woods’ rose (Rosa woodsia), and common snowberry (Symphoricarpos albus). Where present, hydrophytic vegetation is associated with the East Gallatin River and associated floodplain. Common hydrophytic vegetation includes meadow foxtail (Alopecurus pratensis), reed canarygrass (Phalaris arundinacea), woolly sedge (Carex pellita), sandbar willow (Salix exigua), and red-osier dogwood (Cornus sericea).

The applicant is Kelly Gamradt of the City of Bozeman. The project is expected to occur between 5/1/2025 and 10/31/2025.

PURPOSE AND NEED

The residents of the Riverside Water and Sewer District successfully petitioned the City of Bozeman (City) for annexation into the City in April of 2022. Through this annexation, the city will assume responsibility for the sanitary sewer service to the current users within the Riverside Water and Sewer District. Providing sanitary sewer service will, therefore, require the installation of a new sewer force main beneath the East Gallatin River.