The Former Wilsey Bennett facility has been developed since 1903 and used for a variety of industrial purposes, including the manufacture of paints (under Benjamin Moore & Co. from 1903 to 1960), condensers, pumps, machinery, and edible food-grade oils and greases. The site is currently used for truck maintenance, repair, and storage. First Environment supported Wilsey Bennett prior to sale of the property by evaluating the presence of paint pigments and elevated concentrations of metals in aboveground storage tank (AST) area. Our preliminary assessment report identified 19 areas of concern (AOCs), including numerous ASTs, hazardous material storage, former drains and piping, groundwater impact, surface water bodies (i.e., Noes Creek), and spill areas.
First Environment’s additional investigation and delineation activities indicated that the nature of impacted soils and groundwater was too extensive to remediate by soil excavation. As a result, we selected a containment strategy with a deed notice and surface cap to remediate the property. The project team designed the remediation to target the following AOCs:
- Pigment-stained soils, which were intermittently exposed along the bank of Noes Creek and encountered in soil borings and exploratory test pits at various locations
- Three oil seeps, which were first observed emanating from the northern bank of Noes Creek (adjacent to the former Wilsey Bennett site)
- An oil sheen observed on the soils and globules of free product (non-measureable, non-recoverable) observed on groundwater within onsite monitoring wells
- Historic fill material, which has been observed as deep as 12 feet below grade in portions of the site
NJDEP approved First Environment’s Remedial Action Work Plan in February 2005. Prior to implementation of the work plan, we obtained a number of permits in order to proceed with the excavation activities along the environmentally-sensitive Noes Creek. These permits included a Tidelands License, Waterfront Development Permit, and Soil Erosion and Sediment Control Plan.
In total, 2,006 tons of pigment-stained and petroleum hydrocarbon-impacted stream bank soils were excavated and transported offsite for proper disposal. Based on field observations of the disturbed stream bank soils, we extended the excavation to encompass approximately 450 feet of the stream bank. Pigment-stained soils were generally encountered from four to eight feet below ground surface. The excavation was extended upland (or to the north) until no evidence of pigments and/or petroleum sheen was noted or until the location of the proposed barrier was achieved. By conducting the excavation in this manner, First Environment minimized the amount of impacted soil located on the stream side (or down gradient side) of the barrier.
First Environment ensured there was no sediment runoff into Noes Creek during excavation activities by only conducting work during periods of low-tide. In addition, the excavations were completed in 20-foot sections so that disturbed areas could be restored prior to high tide, thereby preventing surface water from contacting disturbed soils. First Environment also used a turbidity barrier to ensure that sediment did not escape the excavation and impact the waters of Noes Creek or the Arthur Kill. We restored the stream bank to a 1:2 grade with fill material and soil erosion sediment control material in accordance with the approved Soil Erosion and Sediment Control Plan.
The subterranean barrier is constructed of nearly 400 feet of 80-mil high-density polyethylene containment wall. It was installed along the northern bank of Noes Creek and designed to protect the surface water from further petroleum seeps and/or sloughing pigments. First Environment used a bentonite slurry within the barrier trench to allow for the required installation depth (12 feet below grade) to be achieved. The slurry enabled us to install the barrier immediately upgradient of the excavated stream bank, so that little or no pigment-stained or petroleum-hydrocarbon-impacted soils were left uncontained. The residual slurry within the trench will also act as an additional barrier to prevent contaminant migration to Noes Creek. The project team backfilled the trench to grade and protected it at the surface with a layer of crushed stone; we also compacted it to withstand the truck traffic normally experienced at the site.
First Environment installed five observation wells along the upland side of the subterranean vertical barrier. Along with existing monitoring wells that contained evidence of free product in the past, they will be used as part of the inspections and biennial certifications.
The Deed Notice for the site details the location and construction of the subterranean vertical barrier, as well as the requirements for regular inspections and biennial certification. At this time, the surface and sub-surface soil concentrations that exceed unrestricted use levels will be addressed via an institutional and/or engineering control to be implemented by the prospective purchaser of the site during the re-development of the property.