National Grid,
Harbor Point, Utica MGP Site

Project Details

Project Name | Harbor Point PAH-Impacted Soil; Peninsula and Gas Plant Excavation Projects
Client | National Grid
Engineer | O’Brien & Gere
Location | Utica, New York
Date | November 2012 – March 2015

Project Highlights

> ISS of 90,000 cy of impacted soils
> Excavation of 120,000 tons
> Work completed within wetlands
> Backfill of excavation areas
> Groundwater cutoff wall
> Temporary access roads on soft, unstable soils
> Temporary water treatment
> Road construction
> Wetland reconstruction

Project Summary

Under three separate phases of work, LAND Remediation served as the prime remediation contractor to National Grid at the Harbor Point MGP Site, located in Utica, New York. Under the first phase, LAND value-engineered an alternate geotechnical approach to the excavation of over 100,000 cy of PAH-impacted soils within a soft, unstable wetland area. LAND performed in-situ soil stabilization on over 90,000 cy of material using a large excavator. An engineered grout was blended with the soils to create a low-permeable soil monolith. Following mixing and predetermined cure-time, conventional excavation equipment was utilized to excavate the center of the monolith leaving a perimeter wall and floor of low-permeability, high-strength material to act as a hydraulic barrier. A cost-savings of over $1M was realized by the owner due to the reduction in groundwater treatment and handling. The excavation areas were backfilled with offsite imported material and native wetlands restored (photo below). Two additional phases of work included excavation of nearly 45,000 cy of MGP-impacted soil within temporary sheeted cells, management and T&D of soils to disposal, and additional shoreline restoration.

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