El Monte Operable unit Eastside Shallow Remedy, San Gabriel Basin Demonstration Project

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The purpose of this project is to construct the five extraction wells, ten groundwater compliance monitoring wells, raw water transmission pipeline, groundwater treatment facility, treated water pipeline, and six re-injection wells. The proposed treatment facility will remove contaminants from the groundwater and restore the aquifer while enhancing the water supply for the region. In addition, the project is part of a regional plan to clean up the EMOU and is recognized by the EPA in their Record of Decision as necessary for restoration of the EMOU aquifer.Project Description.This Agreement covers the activities and costs necessary for the design, permitting, and construction of the five extraction wells, ten monitoring wells, the raw water pipeline, the 250 gpm treatment facility, the treated water pipeline, and the six re-injection wells.Major components are described below.Pre-design ActivitiesThis work item includes the completion of all pre-design activities, including groundwater modeling, well design, discharge study, treatment facility design, pipeline design and groundwater monitoring.Treatment Equipment InstallationThis work item includes the installation of treatment facilities for the removal of VOC’s, and 1,4-Dioxane. VOC’s will be removed by LGAC. 1,4-Dioxane will be destroyed by an ultraviolet/chemical oxidation process. Construct Extraction Wells and Re-injection WellsThis work item includes the final activities necessary to construct the five extraction wells and six re-injection wells. These activities include construction of the wells, well development, installation of the permanent pumps and some minor piping reconfigurations.Compliance Monitoring WellsThis work item includes the installation of ten compliance monitoring wells, which are required by EPA. The wells will monitor the compliance of the shallow zone remedy as described in the Interim Record of Decision for the EMOU. Site WorkSite work will include clearing of the land, grading, modifications to existing site piping, new site piping and appurtenances, vaults, slabs on grade, chemical containment areas, electrical power and controls, and pre-engineered metal buildings.PipelinesRaw and treated water pipelines will be constructed to convey raw groundwater from the new extraction wells to the centralized treatment facility and transport the treated water to the re-injection wells.The purpose of this modification is to update the scope of work, schedule, milestone dates, completion date, and budget. This is necessary due to changes to the project details that have evolved since the agreement was executed over 8 years ago. In addition, an additional $610,000 is being obligated to the agreement. These funds were deobligated from other agreements when they were closed out.

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