Nascolite Site PRP Group – Remedial Investigation, Design, Construction and Operations Services at the Nascolite Corporation Superfund Site
Modeling efforts key to successful regulatory approval of cost effective natural attenuation option
Cornerstone personnel provided remedial investigation, design, construction, and operations services at the Nascolite Corporation Superfund Site, a 35-acre former solvent and monomer recovery facility near Millville, NJ. The initial work included use of a “dynamic” field investigation, non-aqueous phase liquid (NAPL) characterization, facility design, construction services and certification. Post-construction support included gaining USEPA and NJDEP approval of system optimization including the shutdown of two downgradient extraction wells and both of the fluidized activated carbon beds in the treatment plant.
Site conditions were defined using GeoProbe® exploratory borings to delineate NAPL in soils. NAPL presence was determined using hydrophopic dyes and UV fluorescence. Other activities included installation of monitoring wells, aquifer testing, geophysical logging, water level measurements, and NAPL thickness measurements. Cornerstone personnel calibrated a three-dimensional groundwater flow and transport model to site hydrogeology and used this to design a containment-based groundwater remedy, which was installed in 1996 and has successfully contained the plume. Actual pumping rates were very close to model predictions.
The modeling effort has been key to successful negotiations with USEPA to allow the use of natural attenuation for the downgradient portion of the plume. More recently, Cornerstone used transport modeling to illustrate the impact of an off-site MTBE plume on capture zone groundwater quality, which helped gain approval of a 50 percent reduction in flow. Future optimization may include complete shutdown of the treatment system and direct discharge to the local POTW.