Project Summary
ESA was retained to address presumed Historic Fill soil impacts at a 5.5-acre property in Hudson County, New Jersey. The property had historically been used for commercial and industrial purposes since its development in the Mid-1800s. Environmental investigations had previously detected arsenic and lead, metals that are typically related to Historic Fill, across the property.
Challenges
ESA’s client purchased the property in the 1980s and rented the warehouse to various storage and warehousing operations. Environmental Investigations were not conducted by ESA’s client at that time. In 2017, the client entered into contract to sell the property, at which time the Industrial Site Restoration Act (ISRA) was triggered. As a result, client was required to complete a Preliminary Assessment (PA) to determine if potential areas of environmental impacts were present; however, since a PA was not completed when the client first purchased the property in the 1980s, the PA was required to cover all activities and operations presently and historically conducted on the property.
The PA identified several areas of concern (AOCs) that required soil and/or groundwater sampling to determine if environmental impacts were present. Therefore, ESA initiated a Site Investigation (SI) to determine the severity of these impacts, if any. The results of the SI showed that there were arsenic and lead concentrations above NJDEP limits present on the site, but evidence of Historic Fill as defined by NJDEP was only confirmed in one localized area. Typically, if Historic Fill is identified on a property, the Responsible Party (RP) will utilize engineering and institutional controls (capping and Deed Notice) to manage the material. Given the size of the property involved, capping of the entire property would be cost-prohibitive. In addition, since Historic Fill was only identified in one localized part of the site, site-wide capping was also unnecessary.
ESA’s Solution
In an effort to obviate the need to cap the entire site and establish a site-wide Deed Notice, ESA researched the feasibility of using an alternative strategy known as ‘compliance averaging.’ This method of compliance breaks the property into horizontal and vertical sample ‘zones’ through the use of Thiessen Polygons and GIS mapping. The zones are each assigned to a Functional Area (FA) and, if the contaminant concentrations of the zones yield an overall FA contaminant concentration average that is below NJDEP cleanup standards, the entire FA is relieved of having to implement engineering and institutional controls for that particular contaminant.
Outcome
Due to a contaminant hotspot of arsenic and lead in a 0.25-acre part of the property and relatively low arsenic and lead concentrations elsewhere, ESA determined that the implementation of a compliance averaging strategy could significantly reduce the amount of engineering and institutional controls required. After a review of the compliance averaging results, ESA was able to reduce the size of the cap and deed notice to a 2-acre parcel that was centered around the arsenic and lead hotspot. The end result was a savings 60% in environmental costs to the client.