Ardenwood Estate Site Remediation and Closure
Location: Staten Island, New York
Context: Real Estate Transaction
Site remediation and expedited site closure was needed for a privately owned, non-engineered, and unregulated drum and waste storage facility. There were more than 900 drums (including approximately 140 buried drums), and 850 cubic yards of soils disposed during interim remedial action. The drums contained a wide variety of chemical compounds in the form of liquids and sludge material, and the property was listed as a Class 2 (significant threat to public health or environment) on the New York State Department of Environmental Conservation’s (NYSDEC) registry of Inactive Hazardous Waste Disposal Sites. The former drum storage area had become an undeveloped vacant parcel, located adjacent to a densely populated New York City residential neighborhood. The site had remained vacant for a number of years, until a developer wanted to turn a vacant parcel into a multifamily residential development complex.
TerraSure Development, LLC used a guaranteed fixed-price remediation (GFPR) approach to restore the property to residential use. Our firm worked closely with the NYSDEC, to plan and conduct the remedial investigation and develop and implement the remedial action plan. The remedial strategy included excavation and disposal of three soil contamination hotspots, periodic groundwater monitoring until regulatory closure, and deed restrictions to prohibit the placement of occupied buildings directly above the excavated areas.
Challenges emerged during excavation, when an undocumented 72-inch-diameter sewer pipe with drums was uncovered in the subsurface. This discovery would have halted a traditional remediation contract, in that, all activities would stop to remove the pipe, and the project would be delayed for months until the scope cost adjustments could be resolved.
Demonstrating a GFPR approach, our firm convinced the regulator to cover the unexpected sewer pipe with high-density polyethylene (HDPE)-plastic, rather than remove the pipe. This course of action allowed the project to continue without additional expenditure of the owner’s time and money. The site was remediated on schedule, under budget, and to the satisfaction of the regulators and local residents.