Northern Drainage Ditch
Northern Drainage Ditch in the Final Restoration Stages
Following the recapping of three landfills and remediation of the Scrap Metal Yard, site engineers at the Orrington Site shifted their focus to an area located west of the former manufacturing area known as the Northern Drainage Ditch area. Charter Environmental was selected as the contractor to conduct this work under the oversight of CDM Smith and Geosyntec.
The primary objective of the remedial design and approach for the site, approved by Maine DEP, was to first remove soils with concentrations of mercury above the clean-up standards, Media Protection Standards (MPS), established by the Maine DEP.
Work began early in 2017 under harsh winter conditions. As with the vast majority of materials excavated from the site, soils exceeding the MPS were moved to a protected staging area and then loaded onto closed rail cars for shipment to approved off-site disposal facilities.
Prior to the start of excavation of the Northern Drainage Ditch, engineers constructed a bypass system to divert water that naturally flows through the area in order to minimize the need to dewater the area during excavation and to allow workers to more effectively remove soils in dry conditions. A new drainage ditch lined with rip rap and a settling basin was designed to carry clean storm water off the site. Any impacted soils in the area of this new drainage feature were removed prior to beginning the remediation of the existing drainage ditch.
Excavation of the southern section of the new drainage area was completed in early 2017 and removal of all soils with concentrations above the MPS was completed in the spring. Construction of the new northern drainage ditch has been completed. The remediated area where the lower portion of the former Northern Ditch was located was used as a staging area for the Landfill 1 construction in 2018. Once this area is no longer needed for staging activities, final restoration of this portion of the remediated Northern Ditch will be completed.
Full copy is available at the Public repository located at: Orrington Town library - 15 School Street, Orrington, ME 04474
The Final Construction Closure report for the Northern Ditch remediation was submitted to the Maine DEP on November 27, 2017. Maine DEP determined the report to be complete in a letter dated October 16, 2018. Full copy is available at the Public repository located at: Orrington Town library - 15 School Street, Orrington, ME 04474