The project entails removing a current sedimentation structure (Phase I) and building a new settling basin (Phase II) at the Water Treatment Plant at 3575 W Street in the City of Eureka in Humboldt County, California. Phase I work involves removing and disposing of internal mechanical equipment coated in lead-based paint, demolishing and removing the existing sedimentation unit, cutting and capping a waterline, hauling in aggregate base for Phase II, and removing three redwood trees. Phase II work involves developing a three-bay covered settling basin, paving for a new driveway and 6 new parking stalls, installing an oil/water separator, tying into an existing backflow preventer, and installing a water line extension with booster pump station. Phase II requires the installation of 225 lineal feet of water pipeline by conventional trenching within a 2-foot-wide trench at a depth of 4-foot minimum to 5-foot maximum. All trenching will occur within the property limits of the Water Treatment Plant. A total of approximately 70 cubic yard of material will be excavated and temporarily stockpiled adjacent to the trench.