Eagle Wastewater Treatment Plant Facility Expansion

Project Summary

This project is located in Eagle, Idaho in the beautiful foothills northwest of Boise. Like many cities in Idaho, expansion and rapid growth have created the need to expand and improve the existing wastewater treatment facility.

The IMCO project team is providing the City of Eagle with an expanded wastewater lagoon treatment system composed of two new aerated lagoon cells and two new settling lagoon cells, resulting in approximately 19 million gallons of additional water treatment volume.

IMCO is working with a lining subcontractor to complete the major milestone of lining all four lagoons with a HDPE liner. After the lining is complete, IMCO will fill the large lagoons with effluent liquid for testing. This testing is a vital scope that requires close collaboration with the lining subcontractor. Following testing, crews will install aeration equipment used to treat the effluent before discharging to the city of Boise. IMCO crews are also installing HDPE piping, ductile iron piping, valves, and pouring concrete structures.



Eagle, Idaho


Eagle Sewer District

Contract Amount

$6.6 million

Anticipated Completion

October 2021

Project Highlights

Several valves and bends were designed into the HDPE pipeline alignments. IMCO modeled and detailed the pipeline with in-house CAD personnel to show exact fittings, valve, and pipe lengths to lay out critical HDPE welds and meet control points in the Contract. IMCO pre-fabricated nearly all the HDPE piping above the trench and installed it with open cut methods. This project site is also adjacent to a busy highway requiring planned access routes in and out of work areas.