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
- Systematic Planning
- Real-Time Measurements
- Dynamic Work Strategies
Table of Contents
- Site Information
- Project Information
- Triad Approach Information
- Supporting Information
- A broad range of contaminants and source areas were delineated in a single, 5-week field program, such that remedial activities and property transfer could proceed efficiently to the satisfaction of developers and regulators.
- 30,000 analytical results were generated and communicated in real-time using data management and decision support tools.
- A previously-unknown chlorobenzene plume was found and delineated in 4 days through an adaptive sampling program.
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
||Milltown Redevelopment Site
- 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
|Regulatory Lead Program
||Office of Brownfields Reuse
|Triad Project Status
||Field Program Completed
|Reuse Objective Identified
||Residential (including affordable senior housing), Recreational (park surrounding Mill Pond), Commercial/Industrial (retail)
Background Information About Site
- The site is a 22-acre Brownfield site in the heart of downtown Milltown, New Jersey. More than 50 percent of the site is covered with warehouses and industrial buildings.
- Industrial use of the site began with a rubber manufacturing plant in the late 1800s succeeded by numerous other industries.
- The Milltown - Ford Avenue Redevelopment Agency and Middlesex County Improvement Authority (MCIA) entered into an agreement with a developer to develop the parcel for mixed uses, including more than 300 age-restricted residential units, commercial space, and open space along Mill Pond, the main waterway through central Milltown.
- MCIA began planning for the redevelopment in 2001. In 2002, a preliminary assessment was conducted on the site to assemble background information and to identify potential areas of concern (AOCs), as part of developing a preliminary CSM.
- The Milltown - Ford Avenue Redevelopment Agency began assisting with the redevelopment process in 2003, with additional funding from NJDEP. This agency began collaborating with MCIA on the design and implementation of the Stage 2 SI/RI.
Contaminant(s) of Concern
- Halogenated volatile organic compounds (VOCs)
- Metals and metalloids
- Nonhalogenated VOCs
- Polychlorinated biphenyls (PCBs)
- Polycyclic aromatic hydrocarbons (PAHs)
- Total petroleum hydrocarbons (TPH)
- Debris (Buildings, Structures, or Equipment)
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
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:
- Substantially evolve the CSM quickly in a single investigation, such that regulators were satisfied with its completeness.
- Utilize an HRSC strategy to reduce uncertainty sufficiently to allow evaluation of remedial action alternatives and identification of appropriate remedial approaches, or to determine whether redevelopment is economically feasible.
- Reduce the large number of potential AOCs to a smaller number of target areas for remedial action.
- Allow accurate estimation of the cost to implement environmental controls based on NJDEP residential criteria.
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:
- The variety of industrial uses (yielding a wide range of potential contaminants of concern)
- The uncertain distribution of urban/historical fill soil and its impacts (localized "hot spots")
- The possible presence of groundwater in either perched or regional zones, with variable groundwater quality
- An apparent clay layer that may act as a barrier to vertical migration
- Configuration and impacts of the storm and building drain systems
- Site access for sampling due to the presence of old buildings over 50% of the site, and the need to characterize potential releases through building floors and other barriers
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
- Middlesex County Improvement Authority (MCIA): Received EPA Brownfields Assessment Grant
- Milltown - Ford Avenue Redevelopment Agency: Received funding from NJDEP to conduct further environmental assessment, managed technical work, and negotiated an agreement with a redeveloper for the area for residential, commercial, and open space
- New Jersey Department of Environmental Protection (NJDEP): Provided regulatory oversight
- Najarian Associates: Contracted by MCIA, providing project and data management; and serving as the core technical team during site investigation (field technicians, geoscientists, environmental scientists, data management and information technology specialists, engineers)
- S2C2 Inc.: Served as a core technical team subcontractor (on-site lab) during site investigation
- New Jersey Institute of Technology (NJIT): Provided technical support on planning for use of the Triad approach at the site
- Argonne National Laboratory: Provided technical support on planning for use of the Triad approach at the site
- EPA Brownfields and Land Revitalization Technology Support Center (BTSC): Provided technical support on planning for use of the Triad approach at the site
- EPA Environmental Response Team (ERT): Provided support on use of Scribe and Scriblets and web-based applications (data management and decision support tools)
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:
- Served as common ground for communication -- everyone involved in project became familiar with the CSM
- "Matured" or evolved during investigation as more data become available
- Forced the real-time data to be interpreted in context with overall site conditions and contamination patterns (keeping the end goals for the site in mind)
- Became the basis for adjustment to the investigation program when data did not fit CSM
- Defined the end points, fate and transport mechanisms and potential receptors
General aspects of the data collection design and DWS in completing the CSM included the following:
- Site-wide geology defined to a depth of 25 feet using conductivity probe and soil borings
- Historic fill distribution established based on identifying the native soil/fill interface, then field-based analysis for metals, VOCs, PAHs and TPH
- Site-wide shallow groundwater distribution and quality assessed using three tiered decision logic based on the presence of groundwater, drive point grab sampling and pre-packed wells
- Delineation objectives based on a site-specific CSM developed for each location, combining conductivity probe, soil boring, and field-based analytical data
- Decision logic established to define impact boundaries for each location, using collaborative data and decision support tools
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:
- CAT-3 – Data that may be used to define "dirty" when identifying source areas, but have inadequate detection limits or compound specificity to define action level boundaries for contaminant plumes.
- CAT-2 – Data that are of suitable quality to demonstrate that contaminants are above/below action criteria. PQLs of these methods are below NJDEP Soil Cleanup Criteria (SCC) or Ground Water Quality Standards (GWQS), but the methods otherwise do not meet all NJDEP laboratory certification regulations and QA requirements.
- CAT-1 – Data that are collected and analyzed in accordance with the NJDEP’s laboratory certification regulations and the Tech Regs. As such, these data can:
- Confirm that contaminant concentrations are below appropriate remedial action criteria for respective media
- Evaluate the performance of CAT-2 and/or CAT-3 methods
- Refine lists of contaminants of concern
- Provide data where CAT-2 and CAT-3 methods are not available or cannot meet appropriate QA or delineation criteria
Examples of collaborative combinations of CAT-1, CAT-2, and CAT-3 methods for specific target contaminants included:
- Metals in Soil:
- CAT-3 - Hand held XRF, Niton and Spectrace (228 samples)
- CAT-2 - Field based lab bench-top XRF, Spectrace Quantex (346 samples)
- CAT-1 - Certified off-site analysis by Inductively Coupled Plasma Spectrometry (ICP) & Atomic Absorption (AA), EPA Method 6010/7000 (~50 samples, plus additional samples for a few individual metals)
- PAHs in Soil:
- CAT-3 – Ultraviolet (UV) Fluorescence for total PAHs, SiteLab test kits (small number of samples for method demonstration only)
- CAT-2 – Field-based lab Gas Chromatography/Mass Spectrometry (GC/MS), modified EPA Method 8270 with accelerated solvent extraction (280 samples)
- CAT-1 – Certified off-site analysis by GC/MS, EPA Method 8270 (~25 soil/sediment samples)
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
- Direct-Push Analytical Systems
- Direct-Push Groundwater Samplers
- Direct-Push Soil and Soil-Gas Samplers
- Electrical Conductivity
- Mobile Laboratory
- Test Kits
- UV Fluorescence
- X-Ray Fluorescence (XRF)
Specific Technology(s)/Model Used (e.g., SCAPs)
- Geoprobe Systems
- Niton 700 series (portable); Spectrace QuantX (benchtop unit in mobile lab)
- S2C2, Inc.
- Wenner Array Electrical Conductivity Probe built by Geoprobe Systems
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:
- XRF application produced generally higher concentrations when compared to laboratory AA and ICP methods for the same samples
- 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
- 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
- The collection of collaborative CAT-1 metals data focused on the decision range near the SCCs
- 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
- 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.
- 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.
- Scribe (www.ertsupport.org/scribe_home.htm) is a database tool developed by the USEPA's Environmental Response Team (ERT) to assist in managing environmental data. Scribe made available in real-time many of the features and advantages of a relational database while the team was still in the field. After each round of sampling, the data were imported to Scribe, queried, and exported to AutoCAD through an electronic data format created by the project team in Scribe.
- Scriblets is a handheld extension of Scribe used to capture and import sampling and monitoring data collected on handheld personal digital assistants (PDAs). Sample data, real-time analytical results, and sampling location data (coordinates generated using global positioning survey [GPS] survey equipment) were entered into Scriblets in the field and then imported to the Scribe database by connecting the PDA to a laptop computer with a USB cable. The result was an all-electronic data pathway that minimized the potential for transcription errors.
- A project-specific website (www.epaosc.org/milltown) was set up on the EPA ERT web server to disseminate data to stakeholders who could not be present at the site. Maps were posted to the website daily, along with progress reports and information about meeting times and places. Over 200 maps were generated and posted over the 5-week field program. This data communication strategy allowed:
- Daily review of maps and database by the project team and stakeholders for the DWS
- Input on and documentation of decisions regarding sampling locations, depths, and parameters
- Weekly project review meetings with regulators to discuss critical data issues
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
- August 2003: Begin Systematic Planning Process.
- November 2003: Stage 1 SI Field Activities.
- December 2003 - September 2004: Development of Stage 2 Work Plan.
- September 29, 2004: Preliminary Planning Meeting and "Dry Run."
- October 18-22, 2004: Begin Stage 2 SI/RI field work. Mobilization and conductivity probe survey.
- October 25-29, 2004: Initiate AOC soil sampling (mobile labs arrive on site on October 28 and 29).
- November 1-12, 2004: Site-wide program.
- November 15-December 3, 2004: Further delineation of AOCs, including newly discovered chlorobenzene release.
- December 6-10, 2004: Confirmation sampling and installation of pre-pack wells.
- December 13-17, 2004: Demobilization.
- January 13, 2005: Stage 2 SI/RI Field Activities Debriefing.
- July 2006: Delivery of Stage 2 RI/SI Report.
Dates of Operation - Field Work
October 18 through December 17, 2004
Source(s) of Information
- Mack, J. 2006a. Milltown Redevelopment Project Stage 2 SI/RI Report. New Jersey Institute of Technology and Najarian Associates. April.
- Mack, J. 2006b. Milltown Redevelopment Project, Applying Triad Under a State Regulatory Program. New Jersey Institute of Technology.
- Najarian Associates (Najarian), S2C2, and New Jersey Institute of Technology (NJIT). 2004. Stage 2 – Site Investigation and Remediation Workplan (SI/RW), Milltown Ford Avenue Redevelopment Project. August.
- Najarian, S2C2, and NJIT. 2006. Stage 2 – MIA Site Investigation / Remedial Investigation Report, Milltown Ford Avenue Redevelopment Project. July.
- Najarian, S2C2, and NJIT. 2007. Draft Stage 3 Remedial Investigation Report (RIR) for the Minimally Impacted Area. June 8.
Electronic Documentation of Supporting/Related Information
Point(s) of Contact
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
Senior Project Manager
Middlesex County Improvement Authority (MCIA)
101 Interchange Plaza
Cranbury, New Jersey 08512
Last Update: 09/01/2007
To update this profile, contact Cheryl T. Johnson at Johnson.Cheryl@epa.gov or (703) 603-9045.