Use of Dynamic Work Strategies Under a Triad Approach for Site
Assessment and Cleanup - Technology Bulletin
September 2005
Since its inception in 1995, the U.S. Environmental
Protection Agency's (EPA) Brownfields Initiative and other
revitalization efforts have grown into major national
programs that have changed the way contaminated
property is perceived, addressed, and managed in the
United States. In addition, over time, there has been a
shift within EPA and other environmental organizations in
the way that hazardous waste sites are cleaned up.
Project managers, regulators, technology providers, and
other stakeholders are increasingly recognizing the value
of implementing a more dynamic approach to site cleanup
that is flexible and focuses on real-time decision-making in
the field to reduce costs, improve decision certainty, and
expedite site closeout. As shown in Figure 1, the Triad
approach uses (1) systematic project planning,
(2) dynamic work strategies (DWS), and (3) real-time
measurement technologies to reduce decision uncertainty
and increase project efficiency.
Figure 1: The Triad Approach
Dynamic Work
Strategies
Systematic
Project
Planning
Real-Time Measurement Technologies
The EPA Brownfields and Land Revitalization Technology
Support Center (BTSC) is preparing a series of technical
bulletins to provide additional information about how to
implement specific aspects of the Triad approach. This
bulletin focuses on planning and implementation of DWSs,
presenting:
1. Answers to frequently asked questions on
implementing a DWS
2. Summaries of the application of DWS at two
redevelopment sites, including:
Former Cos Cob Power Plant, Greenwich, CT
Assunpink Creek Greenway, Trenton, NJ
3. Sources of additional information for communities and
project teams desiring to implement a DWS and the
Triad approach
Additional information on the BTSC is presented in the
box to the right.
IMPLEMENTING A DYNAMIC WORK STRATEGY
What is a dynamic work strategy?
A DWS allows data collection and cleanup activities to be
performed in real time as parts of an integrated field effort.
The actual number of field mobilizations depends on the
complexity and constraints of a project but is always fewer
than would be required under a static work plan design.
Under the Triad approach, a DWS is specifically
structured to resolve uncertainties about the presence and
extent of contamination, exposure pathways, and
selection of the right cleanup strategy. Real-time project
execution allows projects to reach a successful conclusion
faster, with less expense, and with greater certainty.
Depending on the nature of a project and the judgment of
the project team, a DWS can be planned and written to
deal only with the data collection phase or to encompass
both data collection and remedy implementation. DWSs
that incorporate both sets of activities require more
comprehensive planning and are more technically
demanding, but they greatly improve the efficiency of field
work because collection of additional data, refinement of
the data collection design, selection of the remedy (from a
pre-planned short list of options), and remedy
implementation all can be performed while the project
team is still on site.
About the Brownfields and Land Revitalization
Technology Support Center (BTSC)
EPA established the BTSC (see www.brownfieldstsc.org)
to ensure that brownfields and other land revitalization
decision-makers are aware of the full range of
technologies available for conducting site assessments
and cleanups, and can make informed decisions about
their sites. The center can assist federal, state, local, and
tribal officials plan for use of the Triad approach at a
specific brownfields or land revitalization site. This type of
support includes evaluating available planning documents
to determine how to incorporate elements of the Triad,
such as better use of field analytical techniques or use of
decision support tools. Localities can submit requests for
assistance through their EPA Regional Brownfields
Coordinators, online, or by calling 1 -877-838-7220 toll
free. For more information about the BTSC, contact Dan
Powell at (703) 603-7196 or Dowell.dan@eDa.oov.
Office of Solid Waste and Emergency
Response (5102G)
EPA 542-F-05-008
September 2005
www.brownfieldstsc.org
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Use of Dynamic Work Strategies Under a Triad Approach
Even if a DWS involves data collection only, the project's
bottom line will benefit from rapid generation of higher
data densities in areas of the site where the information is
needed most.
Important features of a DWS include:
A flexible and adaptable approach to sampling
and data collection, that can continually be
adjusted and refined in the field as new data are
generated and data gaps are identified.
An analytical quality control (QC) program that is
also adaptive in nature, collecting QC samples that
focus on the principal sources of uncertainty and
incorporating real-time data QC review.
A clear decision logic applied in the field to guide
the DWS, established and approved prior to the field
program by the project stakeholders. The decision
logic, along with the lines of responsibility,
authority, and communication for decision-
making, is based on the site-specific exposure
pathways of concern, reuse objectives, and data
collection technologies. It is documented in project
planning documents (see the discussion below).
Figure 2 shows a proposed example decision flow
diagram, prepared with the assistance of the BTSC, for a
targeted brownfields assessment (TBA) planned for a
chemical site with concerns about volatile compounds.
This flow diagram presents a synopsis of the entire
technical approach for the investigation of the site,
encompassing multiple environmental media and a range
of potential chemical classes of concern. The diagram
allows the stakeholders to reach major remedial and reuse
decisions concerning the site in a single mobilization that
employs a DWS.
The results of data collection using a DWS are used to
continually refine the conceptual site model (CSM, the
decision-makers' "picture" of site contamination) and the
sampling and analytical approach in real time; in cases
where there are significant unexpected results, revisions
to the decision logic itself or to the overall project
objectives may be needed. The field work continues until
all decision objectives established for the project are
attained with an acceptable level of certainty. The level of
certainty is predetermined by the project decision-makers
during systematic planning efforts. The soundness of
project decisions and attainment of the project objectives
should be verified before demobilization by performing
quality assurance (QA) activities such as a data quality
assessment (DQA) (EPA 2000b).
Fundamental to the success of a DWS
is the ability to manage, review, and
report data from the field to support
fast decision-making. An increasing
number of tools are available to assist
project teams with efficient management of field data. For
example, the Scribe and Scriblets database programs
available from the EPA Environmental Response Team
(see www.ert.org) are designed for data entry and upload
in the field from laptops and personal digital assistants
(PDAs). The uploaded database can be ported to
statistical packages and decision support tools (DST, such
as the FIELDS and SADA software packages); see
http://www.frtr.gov/decision support for further information
about various software tools used for decision-
making and data presentation. DSTs are
discussed in a separate BTSC bulletin.
How is a dynamic work strategy incorporated into
project planning documents?
A DWS does not require a separate project document.
Rather, a DWS is incorporated into the plans typically
prepared for a project, including work management plans
(WMP), sampling and analysis plans (SAP), and QAPPs,
and is thus captured along with the other components of
the Triad approach, including systematic project planning
and real-time measurement technologies. The difference
is that, unlike work plans developed under traditional
approaches, a DWS does not attempt to identify all
sample types, locations, and quantities at the outset of an
investigation. Within the planning documents, the DWS
may identify general sampling approaches (for example,
statistical or judgmental) or initial sampling locations, but it
leaves the details of the data collection approach to be
developed and adapted in the field. This adaptive strategy
applies not only to the sampling approach but also to the
analytical methods, the QA/QC program, the
communication strategy, and other project elements,
which are continually revised and adjusted as data are
generated. Key items to be captured in the project
planning documents are listed below.
The systematic planning process - the project
stakeholders, the project team, site reuse objectives,
types of decisions to be made, the preliminary CSM,
and the amounts and types of decision uncertainty
that can be tolerated
Decision logic and decision trees - decision rules
written as specifically as possible to guide the field
program
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Use of Dynamic Work Strategies Under a Triad Approach
Standard operating procedures (SOP) - clear
methods for sampling and analysis that are not "off
the shelf" but have been evaluated and refined as
necessary to meet the specific project data and
decision needs (for example, through a
demonstration of method applicability)
Data assessment and QA/QC - the tools to be used
for data assessment (for example, statistical routines
and models) as well as the means by which data
quality will be assessed and uncertainty will be
managed in real time through QC checks and QA
oversight activities
Data management and documentation - the
pathways, tools, and formats by which data will
quickly and securely flow from the analytical
instruments to the decision-makers as well as the
documentation trail that will support real-time
decisions while the investigation team is in the field
Communication strategy - roles and responsibilities,
authority, lines of communication and information
flow, communication tools, and the frequency for
decision-making and decision approval
Scheduling and logistical considerations - optimal
investigation time frames as well as how different field
activities, staff, and equipment will be coordinated for
maximum efficiency
Contingencies - major uncertainties associated with
the scope or direction of a DWS that may require
identification of additional or alternate methods in
planning documents (so that the methods are ready
for rapid implementation or expansion as the field
program progresses)
What types of strategies are used to manage
uncertainty in a dynamic work strategy?
Sound defense of project decisions requires effective
management of uncertainty. Under a Triad approach, it is
important that decision uncertainty be managed during the
investigation. Under traditional data collection strategies,
data uncertainty is a major source of decision uncertainty.
Data uncertainty is caused by many different factors. A
very common and important cause of data uncertainty is
that the number of samples collected is found to be
insufficient for decision-makers to be sure that all
contamination has been located. Uncertainty caused by
insufficient sampling density also greatly impacts
estimates of remedial costs because not enough
information is available to know what the most effective
cleanup option might be. Data uncertainty can also be
caused by improper selection or use of analytical
methods; in this case, the decision-makers do not have
the right kinds of data to support risk and remedy
decisions. Triad's systematic planning process addresses
all these kinds of issues and builds their resolution into the
project planning documents before field work begins.
Geoscientists and chemists who are familiar with field
sampling and analytical technologies should be involved in
project planning and in writing the planning documents.
While field work is being done, these personnel should
monitor data generation and the QC results to make sure
that the data will be usable to support project decision-
making within the agreed-upon tolerances for uncertainty.
These tolerances may be expressed qualitatively using
professional judgment or quantitatively using statistics.
Presented below is a partial list of uncertainty
management techniques that have been used
successfully to improve data quality in recent DWS
projects:
"Front-loaded" QC sampling - collecting a higher
proportion of QC samples (for replicate
measurements and spikes) at the beginning of a field
program to allow a confident assessment of method
performance. Once the baseline performance is
established, the QC sampling frequency can be
reduced.
Focused QC checks - altering the nature or
frequency of QC checks to focus on managing
relevant uncertainty because of changes in field
conditions or instrument performance. Examples
include increasing the QC sampling frequency for a
complex or variable matrix that is encountered during
the investigation, adding a new target compound to
calibrations, adjusting the range of the calibration
curve, and increasing or decreasing QC spike
mixtures used as analytical controls.
Use of collaborative methods - using results of
different methods to corroborate or confirm the results
of a specific field-based method. Many programs
have historically used off-site laboratories (for
example, laboratories employing SW-846 methods) to
corroborate results of field methods such as
immunoassay test kits. This approach can foster a
powerful collaborative data set that can be used to
manage multiple sources of uncertainty; the high data
density afforded by the test kits can be used to
manage sampling uncertainty (heterogeneity), while
the laboratory methods can be used to manage
analytical uncertainty. Collaborative data sets are
particularly important when samples have chemical
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Use of Dynamic Work Strategies Under a Triad Approach
concentrations near an action level and the analytical
precision of the field method is insufficient to establish
compliance with or exceedance of the threshold.
Well-homogenized split samples can be submitted for
more rigorous analysis to obtain data that are precise
enough to allow management of this type of decision
uncertainty.
Anticipation of contingencies for measurement
methods - being capable of performing minor method
modifications in the field as necessary. Examples
include adjusting sample volumes, extraction
parameters, or calibration procedures and adding
new method steps (such as sample cleanup steps).
Using a DWS for data collection requires good
coordination among multiple members of a project team
(field crews, project decision-makers, and other
stakeholders) and may challenge the team members in
terms of their roles and level of effort needed. As such,
effective implementation of a DWS requires a cooperative
relationship among all the members of the project team
and a firm commitment to real-time decision-making.
Case studies and brief project profiles describing DWSs in
the context of Triad projects for a broad range of sites are
available at www,triadcentral.org. Two examples are
summarized below.
EXAMPLES OF HOW A DYNAMIC WORK STRATEGY
IS IMPLEMENTED FOR REDEVELOPMENT
INVESTIGATIONS
Example#1: Cos Cob Power Plant, Greenwich,
Connecticut
The Cos Cob Power Plant site is located in the
southeastern corner of Connecticut on Long Island Sound.
The Town of Greenwich plans to reuse the site and
received a TBA grant to assess potential reuse options.
EPA Region 1 requested assistance from the BTSC in
maximizing the efficiency of the TBA by applying the Triad
approach.
/Site Facts
S Former coal-fired power plant that operated from
1907 to the 1960s
s Planned for recreational reuse (walking trails and
playing fields)
s Principal threat is direct contact with
contaminated surface soil
S Contaminants of concern (COC) included
petroleum-related substances, polychlorinated
biphenyls (PCB), and arsenic associated with fly
ash (used as fill) and transformers
Work Plan Development
With the BTSC's assistance, EPA Region 1 revised the
limited, traditional sampling approach originally proposed
for the site and developed a DWS. The DWS called for
random grid sampling and field-based measurement
technologies to expand the extent and density of
investigation across the site for total petroleum
hydrocarbons (TPH), polycyclic aromatic hydrocarbons
(PAH), and PCBs. The goal was to delineate the COCs in
soils at the site in a single mobilization rather than use the
phased approach originally envisioned for the TBA.
During the development of the TBA work plan that
documented the DWS, ultraviolet fluorescence (UVF) test
kits were verified as useful field-based methods for TPH
and PAH measurement through a method applicability
study. This study also allowed the development of
correlation curves between the field test kits and
laboratory analytical methods, allowing estimation of field-
based action levels to be used with the test kits to classify
sampling locations in three ways: "clean," "dirty," or
"uncertain" (requiring collaborative off-site laboratory
data). The field-based criteria were further developed into
decision trees and incorporated into the work plan to
support decision-making in the field. In addition to the
UVF test kits, the TBA work plan specified field-based gas
chromatography (GC) analysis for PCBs by EPA Region
1's mobile laboratory.
Implementation of Dynamic Work Strategy
The field effort at the Cos Cob Power Plant site was
completed in 1 week in February 2003. Direct-push
methods were used to collect soil samples down to 4 feet
below ground surface (bgs) within a 70- by 70-foot
sampling grid extending across the site (see Figure 3).
The sampling location within each grid element was
selected randomly unless a specific area of potential
contamination was identified, in which case a judgmental
(biased) sample was collected. Initially, only samples
5
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Use of Dynamic Work Strategies Under a Triad Approach
collected from the top two 1 -foot intervals at each location
were analyzed in the field, and a percentage of the
samples collected were sent off site for collaborative
analyses. Field analyses were performed for TPH and
PAH at all locations using the UVF test kits, whereas PCB
analyses were performed only in grid elements where
PCB releases were believed to be possible based on
historical information. Selection of samples for off-site
TPH and PAH analysis was biased toward samples with
test kit concentrations in the "uncertain" range (that is, the
concentration range where samples could not be called
"clean" or "dirty" with an acceptable level of certainty
based on the method applicability study). Selection of
samples in this manner allowed for refinement of field-to-
laboratory correlations and of the field-based decision
criteria as the investigation progressed.
Project Results
The dynamic field program at the Cos Cob Power Plant
site rapidly clarified the principal reuse questions and
remedial options for the project team and the Town of
Greenwich. Field-based technologies were used to
increase site coverage (that is, data density) and to limit
decision uncertainty. Key ranges of concentrations and
safety factors were identified and refined to guide data
interpretation and decision-making in the field using real-
time methods, and these ranges also became the focus of
collaborative data collection using off-site methods to
increase decision confidence. Although concentrations of
some COCs (TPH, PAHs, and arsenic) exceeded
Connecticut residential criteria at a number of site
locations, these concentrations were nevertheless
relatively low given the reuse plan for the site. These
findings suggested that limited remedial action combined
with modification of the reuse alternatives or the cleanup
criteria could facilitate site reuse. The Town intends to
use the TBA data to prepare a remedial action plan, which
may involve limited excavation of some areas along with
capping and land use restrictions (to prevent excavation)
in other areas. The Town is planning a recreational reuse
for the site as a waterfront park. Remedial actions (e.g.,
caps) will be incorporated into the park design.
Figure 3: Sampling Locations for Dynamic Work Strategy - Cos Cob Power Plant Targeted Brownfields Assessment
PROPOSED SAMPLING LOCATIONS
FROM THE REVISED WORK PLAN
FOR THE TARGETED BROWNFIELDS
ASSESSMENT (TRIAD APPROACH)
U.S. EPA REGICM I
PRCCEiED PROBABILISTIC 5 AM PL MG LOCATION
3-' S3IL 30RINGS BY TRC, '963
M-3 4- MONITOR MG WE.L BY TRC, '988
SD-1 * SEDIMENT SAMPLE BY TRC. 19S8
Source: EPA. 2004. Case Study of the Triad Approach: Expedited Characterization of Petroleum Constituents and PCBs
Using Test Kits and a Mobile Chromatography Laboratory at the Former Cos Cob Power Plant Site. July.
6
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Use of Dynamic Work Strategies Under a Triad Approach
The DWS applied at the Cos Cob Power Plant site
established the principal contamination issues and reuse
options for the site without the need for additional
mobilizations. The cost savings realized by the DWS as
compared with use of a more traditional, phased
investigative approach were estimated at between 20 and
40 percent. Time was also saved in that the project was
completed in a single mobilization and TBA funding cycle.
Example#2: Assunpink Creek, Trenton,
J New Jersey
( y The City of Trenton has been
f J aggressively implementing the Triad
\ Cj, approach since 2001 as part of its
y> J program to redevelop a large number of
J abandoned industrial sites. DWSs in
particular were used to characterize
/ contamination at approximately 40 acres
Ĥv. / spread out over 5 parcels of land along the
IJ Assunpink Creek which are targeted for
recreational reuse.
Through a systematic planning process involving multiple
stakeholder meetings, a preliminary CSM was developed,
and an investigative approach was formulated that
involved two phases. Phase I was designed to address
the nature and distribution of the historical fill materials
and identify specific COCs and areas of concern (AOC)
for further investigation. Phase I also included a method
applicability study to demonstrate that the field-based
methods proposed for use in the study area could produce
effective data for decision-making.
Based on the Phase I findings, a dynamic work plan was
developed for Phase II investigation of AOCs at the former
wire manufacturer (Crescent Wire) site and the railroad
freight yard. The work plan included multiple features
designed to promote real-time decision-making in the field,
such as:
Technical approach sections that presented the
preliminary CSM for each AOC along with decision
rules, cleanup levels, and "possible scenarios"
encountered in the field that could drive further data
collection and completion of the CSM
Project-specific field sampling and analytical
procedures established during the method
applicability study in Phase I, including geoprobe soil
and groundwater sampling with continuous soil
conductivity measurement and use of field gas
chromatography/mass spectrometry (GC/MS) for
PAHs, immunoassay (IA) test kits for PCBs and TPH,
and x-ray fluorescence (XRF) for metals
A data management and communication section
describing field documentation requirements and
protocols for communication between the field team,
the project management team, and off-site
stakeholders (the City of Trenton and the New Jersey
Department of Environmental Protection [NJDEP])
A schedule and logistics section describing the
preferred time frame for mobilization and the
anticipated duration of the field program
An example of the decision logic presented in the work
plan for the Crescent Wire site is shown in Figure 4.
Implementation of Dynamic Work Strategy
The DWS was incorporated into a request for proposals
(RFP) to hire a technical support contractor for the field
investigation. The project team found that the DWS and
the Phase I results presented in the RFP greatly improved
the quality and creativity of the bid packages and
produced focused yet flexible pricing schemes. The
contractor selected also assisted in finalizing the DWS in
the work plan. When the field investigation began, the
DWS relied on a three-tiered analytical program of
collaborative methods to achieve high sample densities
while still attaining low detection limits for specific COCs at
decision points. The three tiers of methods included field-
based, semiquantitative methods with high sample
throughput for classes of COCs (IA methods); field-based,
noncertified methods with higher specificity (mobile
laboratory GC/MS and XRF); and off-site, certified
methods for specific COCs (SW-846 methods). Sample
results produced using these methods were integrated on
a continual basis to support daily field decisions.
Site Facts
s Sites of interest included a former wire
manufacturer, a railroad freight yard, and repair
shops
S COCs included heavy metals, petroleum
hydrocarbons, PAHs, and PCBs
s The area had been industrialized since the late
1800s; previous investigations had revealed a
need to differentiate between the impacts on
specific sites from general fill materials, because
these are treated differently under NJ State law
Work Plan Development
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Use of Dynamic Work Strategies Under a Triad Approach
Figure 4: Excerpt from Dynamic Work Plan for PCB/Oil-lmpacted Area of Crescent Wire Site
Assunpink Creek Greenways Project, Trenton, New Jersey
Path
Objective(s)
Sampling Requirements
coc
Field
Analytical
Method
Delineation Criteria
Decision Rule
1
Delineate the lateral and vertical
extent of PCB/Oil impacts in on-
site saturated soils, identify a
possible onsite source area(s).
Saturated soils around the
known impacted area.
PCBs
Immunoassay
test kits
NJDEP Soil Cleanup
Criteria (SCC)
From location where impacts were previously
observed, step out at 25-foot intervals and down at
5-foot intervals until concentrations are below the
delineation criteria. Once concentrations are below
delineation criteria, step in once 10 feet. If a potential
on-site source is identified, follow Path 3.
TPH
Immunoassay
test kits
1,000 mg/kg
Metals
XRF
No Criteria
2
Delineate the lateral and vertical
extent of PCB/Oil impacts in on-
site groundwater.
Groundwater around the
known impacted area.
PCBs
Immunoassay
test kits
Class IIA
Groundwater Quality
Standards
From center of worst case soil impacts determined
from Path 1, step out at 25-foot intervals and down at
5- to 10-foot intervals until concentrations are below
delineation criteria.
3
Delineate PCB/Oil impacts in
unsaturated soils, a potential on-
site source area(s).
Unsaturated soils overlying
most impacted saturated
soils and/or groundwater.
PCBs
Immunoassay
test kits
see
From the potential on-site source area, step out at
25-foot intervals and down at 5-foot intervals until
concentrations are below delineation criteria. Once
concentrations are below delineation criteria, step in
once 10 feet.
TPH
Immunoassay
test kits
10,000 mg/kg
Metals
XRF
No Criteria
Source: Langan Engineering and S2C2, Inc. 2002. Dynamic Work Plan for Site Investigation and Remedial Investigation Activities - Assunpink Creek
Greenways Project. December.
The DWS framework allowed for shifts in decision logic to
address new study questions and data gaps as they arose
during the field investigation. As an example, Figure 5
shows the sampling approach that evolved dynamically for
the Crescent Wire site. Initial sampling locations were
selected to delineate a potential hot spot of PCBs and
TPH found during Phase I. However, when the real-time
results for the samples indicated a contaminant plume
rather than a hot spot, the decision logic shifted from hot
spot delineation to assessing the width and source of the
plume. Sampling along the boundary of the upgradient
property revealed similar COCs, and sample collection
continued along the boundary until the edges of the plume
were identified. Now that the CSM had been substantially
improved by the determination that the plume originated
from an upgradient source and was confined to a thin
layer of floating, weathered product, the decision logic
called for a determination of whether the contaminants in
the plume had impacted creek sediments downgradient of
the Crescent Wire site. Under this final phase of the
DWS, a pattern of borings was established along the
eastern, downgradient edge of the site immediately
upgradient of Assunpink Creek. The borings were used to
rapidly map the extent of the PCB and TPH smear zone
and to establish that there were no downgradient impacts
on the creek from the site or the upgradient source.
Overall, therefore, the DWS quickly resolved the primary
decision questions regarding the extent of contamination
at the Crescent Wire site in a single mobilization.
Project Results
The data set collected during the 4-day field program at
the 3-acre Crescent Wire site was of sufficient quality to
support an agreement among the stakeholders regarding
a remedial and reuse strategy for the property. The
project team was convinced that application of the Triad
approach during Phase II allowed successful completion
of the site investigation in a shorter time frame than would
have been required by traditional approaches while
producing a more detailed data set and greater decision
certainty. As a whole, the Phase II investigation activities
for AOCs along Assunpink Creek lasted less than 1
month, and the final report was approved within 3 months
of completion of the final dynamic work plan.
SOURCES OF ADDITIONAL INFORMATION
The Triad approach is encountering ever greater
acceptance by EPA and other federal and state agencies,
as well as by professional and industry organizations.
Communities and project teams interested in
implementing the Triad are encouraged to contact the
BTSC for more information on these organizations, and for
successful examples of Triad applications. More detailed
information on DWSs and on the Triad approach can be
found in the Brownfields Technology Primer Series
document Using the Triad Approach to Streamline
Brownfields Site Assessment and Cleanup, which is
available at http://www.brownfieldstsc.orci; see the text
box on the first page of this bulletin. Project profiles, case
studies, and other information on applying the Triad
approach can be found at htto://www.triadcentral.org. As
additional bulletins about other aspects of the Triad
approach are developed, the BTSC will make them made
available through these web sites.
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Use of Dynamic Work Strategies Under a Triad Approach
Figure 5: Summary of Dynamic Work Strategy implemented for Sampling of the Crescent Wire Site
Assunpink Creek Green ways Project, Trenton, New Jersey
Assumed
Groundwater
Flow Direction
PCB Sediment Detection (Phase I)
Phase II Sample Locations:
*
~
Day 1 Hot Spot Delineation Borings - all contained PCBs, indicating a larger plume.
Day 2-3 Upgradient Plume Delineation Borings - step out borings (along red arrows) define a PCB/TPH plume
moving on-site from an upgradient source.
Day 3-4 Downgradient Plume Delineation Borings - step along the downgradient site boundary (along green arrows)
to verify no impacts to creek from the upgradient source. Lastly, perform additional plume delineation with
step-out borings in the center of the site.
Source: James Mack et a!, 2003. "Characterizing a Brownfields Recreational Reuse Scenario Using the Triad Approach
Assunpink Creek Greenways Project." Remediation. Autumn.
REFERENCES
NOTICE AND DISCLAIMER
Lesnik, B. 2000. "Method Validation for the Resource
Conservation and Recovery Act Program." LC/GC
Magazine, Volume 18, Number 10. October.
U.S. Environmental Protection Agency (EPA). 2000,
"Guidance for Data Quality Assessment: Practical
Methods for Data Analysis" (QA/G-9). EPA/600/R-
96/084. July.
EPA, 2000. "Guidance for the Data Quality Objectives
Process" (QA/G-4). EPA/600/R-96/055. August.
EPA. 2003. "Using the Triad Approach to Streamline
Brownfields Site Assessment and Cleanup," Brownfields
Technology Primer Series. EPA 542-B-03-002. June.
Triad Resource Center Web Site. 2004,
htto://www. triadcentral.org/index. cfm. Accessed
November,
This bulletin was prepared by EPA's Office of Solid Waste
and Emergency Response under EPA Contract No. 68-W-
02-034, The information in this bulletin is not intended to
revise or update EPA policy or guidance on how to
investigate or cleanup Brownfields or other revitalization
sites, Mention of trade names or commercial products
does not constitute endorsement or recommendation for
use.
This bulletin can be downloaded from EPA's Brownfields
and Land Revitalization Technology Support Center at
www,brownfieldstsc,org. For further information about this
bulletin or about the Triad approach, please contact Dan
Powell of EPA at (703) 603-7196, or DOwell.dan@eDa.aov.
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