U.S. Army Corps of Engineers – New England District

Overview:

• Remedial Investigation/Feasibility Study at a Formerly Used Defense Site
• Incremental Sampling Methodology
• FUDSCHEM Data Management

Description:

The former Burlington Army Ammunition Plant is a Formerly Used Defense Site (FUDS) encompassing approximately 70 acres along the banks of the Delaware River in Burlington, New Jersey. It was a contractor-operated, government-owned facility that periodically operated between 1943 and 1973. It was used to manufacture shell bodies for the 81-mm mortar and steel cartridge cases for the 105-mm howitzer.

On 1 January 2019, Bluestone acquired Avatar Environmental, LLC. Bluestone (Avatar) prepared all required Quality Assurance Project Plans in accordance with UFP. Bluestone completed a seven-day water level study to determine the impact of a 6-7 ft tidal range of the Delaware River on the groundwater flow direction at the site. The results of the water level study allowed for the appropriate placement of monitoring wells.

A large-scale field investigation was completed in the Summer of 2018. Incremental Sampling Methodology (ISM) was used to characterized surface and subsurface soil contamination. The ISM approach was generally based on the Interstate Technology Regulatory Council’s 2012 guidance document. The site area was divided into Decision Units (DUs) based on historical uses and likely areas of contamination. Large DUs were further divided into Sampling Units (SUs). Three replicates were collected from each DU/SU.

A sediment investigation was conducted to determine contamination levels along the shoreline. Ten new site wells were installed to complement the six existing wells. All site wells were sampled using low-flow sampling technique. Slug tests (falling and rising head) were completed for all site wells. A comprehensive background sampling program was completed. It entailed the collection of surface and subsurface soil samples using ISM from eight locations and installing and collecting samples from four wells. Bluestone has incorporated all project data into FUDSCHEM, USACE’s online repository for electronic data and documents supporting the FUDS program.

The data collected during the field investigation was used to complete a baseline human health and screening level ecological risk assessment and updated conceptual site model. The results of all the work were documented in a Remedial Investigation Report. The results of the risk assessments will be used to determine if a Feasibility Study is needed.