Economic and transactional considerations often require that land redevelopment activities incorporate accelerated environmental investigation and cleanup programs. It is also of increasing interest to incorporate sustainable practices into cleanup and redevelopment activities. For the Harrison Avenue site, the Triad Approach was used to expedite the high-resolution delineation of a source area within a municipal landfill and facilitate cleanup prior to construction of an urban civic center. The Triad sampling strategy featured in situ screening of soil and groundwater using a MIP, followed by confirmatory vertical profile sampling of soil and groundwater for off-site laboratory analysis. This study found that application of MIP in a dynamic, high-resolution sampling strategy in conjunction with the suitable placement of confirmatory samples, resulted in reduced project cost, and will accelerate redevelopment of the site. In addition, using Triad helped to incorporate green and sustainable practices.
MIP screening generally followed ASTM Standard D-7352 and the Geoprobe® MIP Standard Operating Procedure, Technical Bulletin No. MK3010 (June 2009). The MIP used a polyether ether ketone (PEEK®) return line and a tetrafluoroethene (TFE) Teflon® supply line for the carrier gases, and used the following three probes to screen for site contamination:
The second phase included confirmatory direct-push sampling via vertical profiles, by means of an 8010 Geoprobe® rig, in the soil and groundwater.
|Site Name||Harrison Avenue Landfill|
|Site Type||Municipal Landfills|
|Project Lead Type||State Lead|
|Regulatory Lead Program||Targeted Brownfields Assessment, State Remedial|
|Reuse Objective Identified||Yes|
|Proposed Reuse:||Recreational (mixed and passive use) and Community Center|
An 85-acre municipal landfill is one of eight sites located within a 200-acre brownfields development area (BDA) along the Delaware River in Camden, New Jersey. Redevelopment and revitalization plans for this BDA in the vicinity of the landfill include a community center, indoor and outdoor recreational facilities, and natural areas. The landfill was unlined and operated from 1952 until 1971, when it was closed with a vegetative soil cover. Illegal dumping activities took place at the site through the 2000s. While preliminary investigations revealed it contained mainly municipal solid waste, a more detailed investigation in 2006 revealed a source area of volatile organic compound (VOC) contamination in one quadrant of the landfill. Benzene, chlorobenzene, dichlorobenzenes, and 1,2,4-trichlorobenzene were identified at concentrations above the state cleanup standards in both soil and groundwater. In addition, a grey-black clay layer identified below the waste fill (at approximately 20 to 30 feet below ground surface) was highly contaminated and was believed to be a continuing source of groundwater and soil vapor contamination.
An initial interim remedial measure (IRM) was implemented in 2007 to excavate and dispose of about 14,000 cubic yards of material from the apparent source area. After excavation, residual contamination remained outside of the IRM excavation area which needed to be defined quickly in order to stay within the construction and redevelopment schedule. A Triad-based systematic sampling plan was established using a MIP to collect an initial real-time, high-density data set and from that data, confirmatory samples were selected in order to comprehensively delineate the remaining source material.
The multiple sensors deployed by the MIP, in combination with 3-D visualization software, were proven to be effective HRSC tools for horizontal and vertical delineation of the residual contamination. The real-time data allowed for quick review by the project team and effective placement of further screening and sampling points, resulting in well-defined source areas to be further assessed for remedial feasibility. The qualitative screening data generated by the MIP compared very favorably with the quantitative analytical data for follow-on discrete samples, and the combined data sets defined the target remediation area in high density in one mobilization.
A 40-50 percent reduction of the investigation’s carbon footprint resulted from the use of technologies and practices that were promoted by the Sustainable Remediation Forum. These practices included: using biodiesel; decreasing the amount of investigation-derived waste (IDW) produced from sampling (e.g., bottleware, shipping materials, and decontamination fluids); applying the MIP for expedited site screening; collecting only confirmatory samples, and requiring only one mobilization and demobilization. This streamlined investigation using real-time screening data and the Triad approach saved time, resources, and money compared to a conventional non-dynamic approach.
Application of the Triad approach in conjunction with Green and Sustainable Remediation (GSR) practices was assessed to produce:
Systematic planning activities included:
Stakeholders identified the objective of the investigation to be the high-resolution delineation of remaining source material. Information from the investigation was intended to assist the Brownfield Developer in deciding on a remedial strategy, and an active versus passive development approach for the site.
The Triad-based, high-resolution sampling strategy consisted of two phases: 1) in situ screening of soil and groundwater using the MIP, and 2) confirmatory soil and groundwater sampling via vertical profiles, by means of a Geoprobe®. Six transects oriented perpendicular to the groundwater flow direction were established as a framework for data collection during the planning stages of the MIP investigation; these transects covered the residual contamination and downgradient areas.
A total of 18 locations were screened with the MIP. A 3-D model showing the ECD responses was generated and updated daily during the MIP investigation. Once the area of contamination was defined, confirmation samples were collected from 13 locations in order to obtain quantitative analytical data needed to identify the specific compounds and their concentrations.
A high-density data set was generated from the field MIP data and electronically transmitted to the project office daily which allowed updating of the 3-D contamination model. The updated model was uploaded onto the project file transfer protocol (ftp) site and reviewed during daily conference calls between CDM and NJDEP to refine the locations of other planned MIP borings and confirmation borings to facilitate a higher-resolution delineation of the contamination.
In this investigation, it was critical that the heating element of the MIP be maintained above 132°C (boiling point of CB) to allow volatilization for detection by the MIP’s ECD. The advancement rate of the MIP was often slowed from a starting rate of 1 foot per minute in order to maintain an approximate temperature of 140°C, such that times of up to 10 minutes elapsed before advancing the MIP to the next 1-foot interval. Because of ECD sensitivity limitations, the MIP may not be appropriate at all sites.
The tool is geared toward sites with known contamination at concentrations above low-level detection limits typically achieved in analytical laboratories (less than 0.01 parts per million (ppm). MIP detection limits for this investigation were estimated at 0.25-1 ppm total chlorinated VOCs.
Direct-push technology using an 8010 Geoprobe® was used to obtain confirmatory soil and groundwater samples. From each boring location, one to four soil samples were collected depending on the number and intensity of the MIP detections and the clay layer thickness. Within the saturated zone, two to five groundwater samples were collected throughout the thickness of the aquifer, again dependent on elevated MIP responses. Soil boring samples were collected in 2-inch acetate sleeves, which were subsampled for VOCs using EnCoreTM samplers. Total organic carbon (TOC) samples were also collected from each sleeve after homogenizing the remaining soil. Groundwater samples were collected through a check valve connected to Teflon®-lined tubing. Temperature, conductivity, dissolved oxygen, pH, oxidation-reduction potential, and turbidity were also measured in the groundwater using field meters (YSI Model No. 600 XL and LaMotte Model No. 2020).
TQRS not prepared
MIP ex situ response tests were conducted at the start of each day to ensure that the entire system was working correctly and to measure/confirm the trip time. (The trip time is the time it takes the contaminants to move from the downhole probe through the trunkline to the detectors, and is used by the MIP software for depth calculations.) The ex situ response tests involved exposing the probe to a known concentration of target contaminant (CB) in a test cell.
Quality control samples, including trip blanks (daily), field blanks (after each decontamination event), and duplicate samples (5% of investigative samples), were collected during confirmatory soil and groundwater sampling according to NJDEP requirements. None of the analytical data were rejected based on quality control samples.
3-D software models of contaminant iso-contours and geology were provided by ZEBRA Environmental and by Rockware, Inc.
|Expediting Sustainable Brownfields Redevelopment by Applying Triad Using the Membrane Interface Probe.” Maria D. Watt, Michael Burlingame, Jessica R. Beattie, Melissa Koberle, and Brad Carlson. Remediation Journal Autumn 2010 Volume 20 Number 4 Page17-37|
|Integrating Green and Sustainable Remediation Practices into an Urban Brownfield Redevelopment Project (10,283 KB)|
To update this profile, contact Cheryl T. Johnson at Johnson.Cheryl@epa.gov or (703) 603-9045.