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Use of an On-site Laboratory and Decision Support Tools to Delineate a Range of Organic Compounds and Metals in Soil and Groundwater at the Milltown Redevelopment Site, Milltown, New Jersey

Triad Elements Used

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Table of Contents

  1. Site Information
  2. Project Information
  3. Triad Approach Information
  4. Supporting Information

At-a-Glance

Summary 

The Milltown Redevelopment site is a Brownfields site in Milltown, New Jersey. A Stage 2 Site Investigation / Remedial Investigation (SI/RI), as defined under New Jersey state guidance, was conducted using the Triad Approach during November and December of 2004. This SI/RI was performed under a $350,000 Brownfields Assessment Grant by the U.S. Environmental Protection Agency (EPA), with additional funding from the State of New Jersey. EPA provided further support in implementing the Triad Approach through its Brownfields and Land Revitalization Technology Support Center (BTSC).

The primary project goals of the Stage 2 SI/RI were to (1) evolve a conceptual site model (CSM) of site geology, hydrology, and contaminant fate and transport by collecting soil, sediment, and groundwater samples and geologic profiles on a regular grid, and (2) delineate potential areas of concern (AOCs) on a high-resolution grid spacing of adaptive sampling locations. These goals were attained using an on-site mobile laboratory in combination with data management and data management tools available from EPA. Over 30,000 soil and groundwater sample results were generated over a 5-week field effort for metals and a range of organic contaminants, completely delineating known (as well as previously unknown) contaminants at the site. The results of the investigation were used to develop estimates of contaminated soil volumes that could provide a basis for negotiations with the potential buyer and developer of the property.

The Stage 2 Triad investigation divided the property into two fundamental sections, a portion known as the Minimally Impacted Area (MIA) and another portion with assessed soil and groundwater impacts. The MIA included over 80% of the property. Designating the MIA allowed the developer to begin redevelopment work in the MIA while additional studies were performed in the other, more impacted portion of the site.

1. Site Information

Site Name Milltown Redevelopment Site
Location Milltown, NJ
Site Types 
  • Manufacturing Process
  • Paint/Ink Formulation/Use
  • Pharmaceutical Manufacturing Facility
  • Rubber Manufacturing
  • Textile Dye Manufacturing
  • Warehouse Facility
Project Lead Organization New Jersey Department of Environmental Protection (NJDEP)
Project Lead Type  State Lead
Regulatory Lead Program  Office of Brownfields Reuse
Triad Project Status Field Program Completed
Reuse Objective Identified  Yes
Proposed Reuse:  Residential (including affordable senior housing), Recreational (park surrounding Mill Pond), Commercial/Industrial (retail)

Background Information About Site 

Contaminant(s) of Concern 

Contaminated Media 

Project Results and Outcomes 

The field team used a high-resolution site characterization (HRSC) approach to sample over 400 locations in slightly more than 5 weeks. The field team collected more than 130 groundwater samples and 600 soil samples, generating over 30,000 analytical results that were entered into the project database and underwent quality control (QC) review in a short time.

The benefits of streamlined data acquisition and processing were evident during the discovery and investigation of a previously-unknown chlorobenzene plume. During a site walk-through immediately preceding the Triad investigation, a vat was discovered under a formerly used loading dock that had been obscured by heavy brush. A sample from the vat verified the presence of chlorobenzene. The dynamic work strategy (DWS) provided a flexible means to adapt the sampling strategy after the discovery was made in the field to complete the delineation using several successive rounds of adaptive sampling. This plume was delineated in approximately 4 days after 63 groundwater and 28 soil samples were collected from 46 sampling locations.

The primary recommendation from the Stage 2 SI/RI program was to divide the Site into two major components: a MIA and areas requiring further investigation. A Remedial Investigation Report (RIR) has been prepared for the MIA, which will enable redevelopment to proceed on a large portion of the Site as other portions of the Site undergo more complex and time consuming remediation efforts.

2. Project Information

Project Objectives/Decisions 

The Milltown ? Ford Avenue Redevelopment Agency and MCIA sought to expedite the characterization of an urban Brownfields site so that it could be redeveloped for mixed use, including recreational, retail, and residential (affordable housing for seniors and others). The results of the investigation would support streamlined cleanup (soil removal) and property transfer. The Triad Approach was applied to:

Remedial Phase

Site Investigation (Includes RI/FS or Similar Detailed Investigation Work)

Triad Project Benefits 

The systematic planning approach allowed for integrated involvement with the regulators and other stakeholders, resulting in shorter review times and expedited completion of the project to the satisfaction of all stakeholders. A close working relationship was forged over the 5-week field effort, in part as a result of the frequent on-site presence of the NJDEP case manager and daily and weekly project briefings meetings with the stakeholders.

The DWS developed prior to mobilization facilitated the rapid delineation of a chlorobenzene plume in groundwater after the vat of waste was discovered beneath a loading dock. Use of gas chromatographs (GCs), X-ray fluorescence (XRF) detectors, and other on-site instrumentation made the DWS possible by gathering, interpreting, and sharing data fast enough to support real-time decisions. Decisions on whether to excavate additional materials were made in the field, often in a matter of minutes. If there were questions about a certain area of the site, the area in question could be sampled rapidly enough to decide in the field whether the area was a source or AOC that required further investigation.

The on-site methods allowed the project team to gather a high-density data set to statistically determine cleanup and reduce data uncertainty at a lower cost than traditional off-site laboratory methods. For example, a total of 410 soil samples were analyzed for the site using XRF, including 359 samples from the excavation area.

The Triad Approach was the impetus for effective communication of the findings to the stakeholder group and the public. Three presentations of the Triad findings were made to the public. The high-resolution sampling and high-density data set provided the public with the confidence that environmental issues were properly addressed.

Cost and Time Savings 

Cost and time savings were not quantified by the project team.

3. Triad Approach Information

Systematic Project Planning 

A large, diverse stakeholders group, that included representatives from federal, state, and local agencies as well as a potential site developer, was formed to oversee and direct the project. Meetings of all stakeholders were held periodically throughout the project planning cycle, which began 1 year before the field work commenced. A smaller technical team met regularly throughout the planning and execution of the field work, culminating in a series of weekly meetings held at the site during the field activities in November and December of 2004.

The stakeholders? group identified several concerns during the planning process, primarily: 1) implementation of a sampling and analytical approach that did not strictly comply with New Jersey Technical Requirements for Site Remediation (New Jersey Administrative Code 7:26E, nicknamed the NJDEP "Tech Regs"), and 2) effective management of the sheer volume of data that would be generated by field analytical methods over a relatively short, 2-month time frame. Thus, the planning process required more time and effort up-front than expected to achieve regulatory acceptance of data collection and management approaches that diverged from the Tech Regs.

The preliminary CSM was provided in detail in the planning documents, including the Stage 2 Work Plan. A number of focused field efforts were conducted throughout the planning phase of the project to build the preliminary CSM, including a wetland survey, geophysical investigation, test borings, and the Stage 1 SI program. These activities were necessary, not only to build the CSM, but to help the team establish the boundaries of the investigation and identify logistical considerations for the Stage 2 field activities.

For this project, the Stage 2 Work Plan defined an acceptable level of uncertainty as establishing that 75 percent of the study area was either "clearly clean" or "clearly dirty." General data gaps and other challenges for the investigation in meeting this goal included:

These challenges were addressed in the systematic planning process through stakeholder collaboration in preparation of the Stage 2 Work Plan, which laid out options, investigative tools, and approaches but left significant flexibility for the field team during the DWS.

Project Team Description 

Dynamic Work Strategies 

The DWS was outlined in flow charts and text included with the Stage 2 RI/SI. The DWS anticipated the need for rapid delineation of AOCs and provided decision logic diagrams to facilitate delineation, even though sampling locations were not specified. After preliminary review in an EPA Scribe database, the field data were downloaded to AutoCAD. Because Scribe provided quick turnaround of preliminary sample results, optimal adaptive sampling locations were identified shortly after previously collected sample results were reviewed in Scribe and plotted in AutoCAD (PDF, 256 KB). In this manner, plume delineation was expedited and the CSM was refined to explain the likely source of the plume and mechanisms that contributed to its spread.

Therefore, the focus of the DWS was on the CSM. Throughout the DWS, the CSM:

General aspects of the data collection design and DWS in completing the CSM included the following:

Site-Wide Investigation

Area Specific

Decision Logic 

As discussed above, decision logic for the DWS was incorporated into the Stage 2 SI/RI work plan. The decision logic was summarized in the form of flowcharts (PDF, 39 KB) and data collection strategy tables (PDF, 97 KB).

Real-Time Measurement Technologies 

Because of the broad range of potential contaminants, the on-site laboratory contractor, S2C2, Inc., mobilized significant analytical capability to the field; three separate laboratory trailers were mobilized, consisting of a VOC laboratory, a metals laboratory, and a semivolatile organics laboratory for the analysis of PAHs and PCBs. The mobile laboratories were used to generate data in real-time in the field. To manage the regulatory and analytical uncertainty associated with these methods, a select number of sample aliquots were sent to an offsite NJDEP-certified laboratory for collaborative analysis. The certified laboratory data was referred to a Category (CAT) 1 data, while the field methods were said to generate either CAT 2, or CAT 3 data, depending on the relationship of the practical quantitation limits (PQLs) of the instrument to the action levels for each potential contaminant of concern. These categories of data are defined in the Tech Regs as follows:

Similarly to PAHs, mobile laboratory GC and GC/MS methods were used to generate CAT-2 data for PCBs, TPH, and VOCs, with collaborative CAT-1 data generated for a subset of samples using off-site laboratory methods (EPA Method 8082 for PCBs, Method 8015M for TPH, and Method 8260 for VOCs). Additional information concerning the real-time methods and collaborative data sets for the Milltown site is presented in the Stage 2 RI/SI Report and the subsequent Remedial Investigation Report (RIR) for the MIA.

Technology Category(s) for Sampling and Analysis 

Specific Technology(s)/Model Used (e.g., SCAPs) 

Technology Vendor(s)

Attached Technology Quick Reference Sheet (TQRS) Form 

TQRS not prepared


Data Quality Assessment 

The Stage 2 SI/RI work plan, combined with the Tech Regs, specified QA requirements for the CAT-1, CAT-2, and CAT-3 data generated at the Milltown site. In general, the QA program applied during the DWS found that the on-site and off-site laboratories met method performance requirements and expectations. In regard to the utility of the XRF data, however, the project team noted the following in reporting the SI/RI data:

  1. XRF application produced generally higher concentrations when compared to laboratory AA and ICP methods for the same samples
  2. NJDEP SCC cleanup goals were not specifically linked to a particular analytical method, but they have historically been evaluated against AA/ICP acid digestion procedures
  3. NJDEP wanted demonstration of a strong correlation before XRF data were used for decision-making, and additional certified laboratory AA/ICP analyses were required to bolster the XRF-to-lab correlation
  4. The collection of collaborative CAT-1 metals data focused on the decision range near the SCCs
  5. A combination of non-parametric bin analysis and linear regression analysis was used to develop correlations between XRF and the off-site laboratory CAT-1 data
  6. The collaborative data sets for metals allowed estimation of confidence levels associated with comparisons of XRF data to SCCs based on the correlation and bin evaluations.
  7. An acceptably high level of confidence was demonstrated in the XRF data for the following metals: arsenic, copper, lead, nickel, vanadium, and zinc.

Data Management Approach and Tools 

EPA?s Brownfields and Land Revitalization Technical Support Center (BTSC) identified Scribe and Scriblets as data management tools that would meet the project team?s needs for data management and address stakeholder concerns.

The use of data management tools and data communication protocols for the Milltown site are described in greater detail in a mini-case study prepared by the BTSC and posted by the Federal Remediation Technologies Roundtable at:http://www.frtr.gov/decisionsupport/DST_CaseStudies.htm.

4. Supporting Information

Key Triad Project Milestones 

Dates of Operation - Field Work

October 18 through December 17, 2004

Source(s) of Information

Electronic Documentation of Supporting/Related Information

PDF Mack, J. 2005. Milltown Redevelopment Project Triad Investigation: Data Management Program. Presented at Brownfields 2005, Denver, CO, November 3. (2.6 MB)
Link U.S Environmental Protection Agency (EPA). 2005. Case Study for the Use of a Decision Support Tool: Using SCRIBE to Manage Data during a Triad Investigation, Milltown Redevelopment Site, Milltown, New Jersey.

Point(s) of Contact 

James Mack
Technical Support and Project Oversight for New Jersey Department of Environmental Protection
New Jersey Institute of Technology - NHSRC Technical Assistance for Brownfields (TAB)
Newark, New Jersey  07102
Telephone icon 973-596-5857
E-mail icon mack@adm.njit.edu

Denise Nickel
Senior Project Manager
Middlesex County Improvement Authority (MCIA)
101 Interchange Plaza
Cranbury, New Jersey  08512
Telephone icon 609-409-5002
E-mail icon drn@mciauth.com

Last Update:  09/01/2007

To update this profile, contact Cheryl T. Johnson at Johnson.Cheryl@epa.gov or (703) 603-9045.