United States
Environmental Protection Agency
Office of Solid Waste and
Emergency Response (51 02G)
EPA542-F-09-004
December 2009
Green Remediation Best Management Practices:
Site Investigation
Office of Superfund Remediation and Technology Innovation
Quick Reference Fact Sheet
The U.S. Environmental Protection Agency (EPA) Principles for
Greener Cleanups outlines the Agency's policy for evaluating
and minimizing the environmental "footprint" of activities
undertaken when cleaning up a contaminated site.1 Use of
the best management practices (BMPs) recommended in
EPA's series of green remediation fact sheets can help project
managers and other stakeholders apply the principles on a
routine basis, while maintaining the cleanup objectives,
ensuring protectiveness of a remedy, and improving its
environmental outcome.2
Overview
The need for site investigation is common to cleanups
under any regulatory program. An investigation can occur
at all points in the cleanup process, from initial site
assessment through waste site closeout. A site
investigation generally is undertaken to:
Confirm the presence or absence of specific
contaminants
Delineate the nature and extent of environmental
contamination
Identify contaminant sources
Provide the data necessary to assess potential risk to
human health and/or the environment
Gather the data needed to determine if a remedial
action should be taken
Understand site characteristics impacting the remedy
design, construction, or operation and closeout, and
Evaluate performance of a remedial action.
Site investigations typically involve sampling of soil and
groundwater using various drilling and well installation
technologies and analysis of samples at offsite
laboratories. Investigations also may include sampling of
sediment, surface water, soil gas, or indoor air; searching
for underground storage tanks (USTs) or other buried
objects; or evaluating demolition material containing
asbestos, lead-based paint, or other toxic products.
Planning for Site Investigation
Consideration of green remediation options early during
the project design phase will help reduce cumulative
environmental footprints of a cleanup. Effective planning
will include identification of investigative decision points in
context of a site's unique contamination scenario and
logistics, while accounting for potential remedies and
anticipated site reuse.
At each decision point, strategies and methods can be
evaluated to determine which are likely to best address the
core elements of a green cleanup:
Reducing total energy use and
increasing renewable energy
Materials
& Waste
Energy
Core
Land & Elements
Ecosystems
Water
Reducing air pollutants and
greenhouse gas (GHG)
emissions
Reducing water use and
negative impacts on water resources
Improving materials management and waste reduction
efforts, and
Enhancing land management and ecosystems
protection.
A green site investigation relies on information gained
from a thorough preliminary assessment that identifies
target areas and site conditions through minimally
intrusive techniques. Use of innovative field analytics and
direct sensing tools can reduce the environmental
footprint of follow-on characterization or cleanup
activities, particularly by limiting mobilizations in the field
and increasing the density of analytical data. More
targeted remedial actions and "surgical" removal actions
also can be achieved through use of high resolution
sampling tools during site investigations.
Initial BMPs for a site investigation include:
Evaluating feasibility of using a mobile laboratory, field
analytical methods, or direct sensing tools
Scheduling activities for appropriate seasons to reduce
delays caused by weather conditions and fuel needed
for heating or cooling
Identifying local sources of energy efficient machinery
and vehicles and alternative fuels
Establishing electronic networks for data transfers and
deliverables, team decisions, and document
preparation, and selecting electronic products on the
basis of comparisons available in the Electronic Product
Environmental Assessment Tool (EPEATฎ)
Selecting facilities with green policies, for worker
accommodations and periodic meetings
Reducing travel through increased teleconferencing,
compressed work hours, and flexible work locations,
and
Identifying options for integrating renewable energy
resources, including those extending throughout
cleanup activities.
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Portable electricity
generators equipped
with photovoltaic
panels and batteries
can be used to power
investigative equipment
such as chilling or
heating units.
Procurement of goods and services offers other
opportunities for conserving natural resources:
Incorporate green specifications into solicitations and
contracts, with respect to environmentally preferred
purchasing of materials, awards to contractors with
green policies and procedures (such as routine use of
water efficient and Energy Starฎ equipment) and
periodic reporting of resource reductions
Select service providers, product suppliers, and
analytical laboratories from the local area and
coordinate service and delivery schedules, to reduce
fuel consumption and associated air emissions, and
Specify laboratory analytical methods generating less
waste and solvents, such as solid phase micro extraction
(SPME), pressurized fluid extraction, microwave
extraction, and supercritical fluid extraction, if
comparable accuracies can be achieved; for example,
SPME provides a single-step process that can reduce
sample preparation time by as much as 70% while
using little or no solvents.
Collection of representative data during the first round of
field activities reduces the need for subsequent sampling.
Development of a well conceived site sampling plan can
help assure that collected data truly represent a site.
Systematic planning, a critical component of optimized
strategies for investigating hazardous waste sites, involves
identifying key decisions to be made, developing a
conceptual site model (CSM) to support decision making,
and evaluating decision uncertainty along with
approaches for actively managing that uncertainty. The
CSM combines analytical data with historical information
to identify data gaps and allows for refinement as
additional data become available.
Collecting information dynamically and in real time and
adjusting the work according to the field findings will
minimize mobilizations. Dynamic work strategies that
employ data visualization, dynamic sampling programs,
and quality controls to minimize uncertainties reduce the
need for repeated mobilizations and additional sampling.
Use of the Triad approach can help project managers
integrate systematic planning, dynamic working strategies,
and deployment of these real-time measurement tools. 3
Energy Use & Renewable Energy
Fewer field mobilizations can result in significant savings
of fossil fuel and minimized emission of GHG and other
air pollutants. Real-time field measurements can
immediately provide data to help determine the next
course of action during a single sampling event. Real-time
data collection technologies include:
Direct sensing technology such as the membrane
interface probe, laser-induced fluorescence (LIE) sensor,
and cone penetrometer testing (CPT)
X-ray fluorescence analyzers for metals
Soil gas surveys for volatile organic compounds (VOCs)
Portable gas chromatography/mass spectrometry for
fuel-related compounds and VOCs in soil and
groundwater
for analyzing soil and groundwater
such as petroleum, metals,
biphenyls, pesticides, explosives, and
Field test kits
contaminants
polychlorinated
inorganics, and
Geophysical surveys for locating USTs, buried steel
drums, and boundaries of disposal areas.
Profile: McGuire Air Force Base, C-l7Hangar Site,
New Hanover, NJ
* Used a Triad decision making approach to complete
characterization ofVOC contamination of soil and
groundwater ahead of schedule, consequently reducing
the fuel consumption, land disturbance, and dust
generation associated with additional sampling days
Used investigative tools such as CPT and fuel fluorescence
detectors to generate over 4,500 analytical results in real
time, which expedited decision making in the field and
avoided fuel use associated with transporting samples to
an offsite laboratory
* Determined through real-time measurements that natural
attenuation of halogenated VOCs was occurring, and
avoided excess land disturbance and fuel consumption by
incorporating monitored natural attenuation into the
remedy
* Precisely identified a smear zone of Stoddard solvent,
allowing it to be surgically excavated with minimal land
disturbance and fuel consumption
Recommended BMPs for selecting other equipment and
processes that minimize fuel and energy consumption
include:
Limiting the number of vehicles deployed onsite, and
renting electric, hybrid, or hydrogen fuel cell vehicles
Instituting idle reduction plans, such as machinery
shutdown after three minutes of non-use
Compressing shipments to offsite laboratories whenever
feasible
Using in situ data loggers wherever appropriate to
monitor water levels and water quality parameters
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Using solar-powered telemetry systems to remotely
transmit logging data directly to project offices
Using rechargeable batteries for handheld data loggers
and other field instruments
Using direct-push technology (DPT) for well drilling,
which is 50-60% more time efficient than rotary drill rigs
and avoids drill cuttings that require assessment and
disposal of investigation-derived waste (IDW)
Segregating soil and groundwater collected from
different areas; in many states, media analytically
determined to be clean can be deposited onsite rather
than transported for offsite disposal, and
Disposing IDW at the nearest permitted facility.
Air Pollutants & GHG Emissions
Air emissions from mobile sources can be reduced
through use of various new technologies. Diesel emission
control filters, for example, can reduce particulate matter
emissions by as much as 89% and nitrogen oxide
emissions by as much as 80%. Switching from low-sulfur
to ultralow-sulfur fuels will reduce emissions of sulfur
dioxide (an acid rain-causing air pollutant) and also
allows use of emission control systems that would be
damaged by fuels with a higher sulfur content. Ultralow-
sulfur diesel has become the standard in most states; it
contains no more than 15 ppm sulfur (S), in comparison
to the 500 ppm S in low-sulfur diesel.
Any technology that reduces duration of drilling and
groundwater pumping or purging helps reduce the
cumulative amounts of pollutants released to the air.
Examples include sonic drilling and passive (diffusion-
based) sampling devices.
Deployment of diesel-powered machinery, vehicles,
and equipment over six months of investigations cou
emit nearly 32,000 pounds of CO2/ based on a
consumption of more than 1,400 gallons of diesel.4
d
Relative Diesel Consumption of
Common Investigative Activities over Six Months
(gallons)
Transportation, operation, and support for a rotary
drilling rig for four weeks
Groundwater sampling with a submersible pump
driven by a 2.5-hp gasoline-powered generator
Deployment of a truck-mounted DPT rig for
subsurface sampling
Operation of utility trucks for equipment
maintenance, groundwater and soil sampling, and
Periodic truck delivery of small equipment and
supplies and disposal of nonhazardous waste
IDW transfer to a disposal facility by way of tractor
trailer
293
45
400
300
260
125
Total disssl consumed: 1,423 gallons
Water Use & Impacts on Water Resources
Green remediation strategies help reduce consumption of
fresh water, reclaim or reuse uncontaminated water,
minimize potential for waterborne contamination, and
minimize introduction of toxic processing materials during
a site investigation. Recommended best practices include:
Using waterless drilling techniques such as DPT
Exploring options for reusing operational graywater and
capturing rainwater for tasks such as irrigation or dust
control
Returning unused clean water to surface water bodies
rather than discharging it to a public sewer system
Using low-flow sampling equipment wherever possible
during monitoring, to minimize purge volumes and
energy consumption while producing little IDW
Use of passive diffusion
hag samplers reduces
or eliminates purge
water associated with
well sampling; multiple
vertically-placed
samplers can provide a
vertical profile of
groundwater samples at
one-foot intervals.
Steam-cleaning or using phosphate-free detergents
instead of organic solvents or acids to decontaminate
sampling equipment
Containing decontamination fluids and preventing their
entrance into storm drains or the ground surface
Treating potentially contaminated purge water through
use of appropriate treatment techniques such as
activated carbon filtration prior to discharge to storm
drains or waterways
Using closed-loop cleaning systems relying on
graywater to wash non-sampling related machinery and
equipment
Using biodegradable hydraulic fluids on hydraulic
equipment such as drill rigs
Selecting groundwater monitoring equipment made of
noncorrosive material, to avoid potential cross-
contamination and equipment replacement, and
Quickly restoring any vegetated areas disrupted by
equipment or vehicles, to control stormwater runoff and
avoid soil transport to surface water bodies.
Integrating the needs of remedial and monitoring phases
during design of sampling wells will help reduce
subsurface drilling throughout the life of a cleanup. Well
designs also can accommodate a site's potential cleanup
remedy(s) and reuse goals, in ways that meet the site's
future demand for water while preserving any portions of
the property targeted for specific use.
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Materials Management & Waste Reduction
Land Management & Ecosystem Protection
Site investigation procedures typically involve use of an
assortment of manufactured products such as personal
protective equipment (PPE), sample containers, and
routine business materials. Green purchasing considers
product lifecycles and gives preference to:
Products with recycled and biobased contents such as
agricultural or forestry waste instead of petroleum-
based ingredients
Products, packing material, and disposable equipment
with reuse or recycling potential, and
Products manufactured through processes involving
nontoxic chemical alternatives.
IDW generation and management account for a
significant portion of the environmental footprints of site
investigation. IDW includes drill cuttings, well purge water,
spent carbon from filtration equipment, reagents used with
environmental field test kits, contaminated PPE, and
solutions for decontaminating non-disposable PPE and
equipment.
Reducing the volume of generated IDW will decrease the
need for related containers such as plastic disposal bags
and 55-gallon storage drums, and for treatment or
disposal of IDW in an appropriate hazardous or
nonhazardous waste facility. Recommended BMPs to
reduce the volume of routine waste or IDW and decrease
materials consumption include:
Recycling cardboard boxes and beverage bottles
Reducing use of single-use plastic bags
Reducing the number of sampling days
Using onsite analysis and other real-time measurement
technologies to reduce needs for sample packing
materials
Selecting test kits that generate less waste, such as soil
samplers with reusable handles for coring syringes, and
Segregating drill cuttings by appropriately stockpiling
next to a borehole and awaiting analytical results; under
many cleanup programs, clean soil may be distributed
near boreholes or backfilled into a boring.
Explore Web-based calculators, software models, and other
Footprint Assessment \oo\s accessible on Green Remediation
Focus (http://www.cluin.org/greenremediation), such as the:
CICA Compliance Summary Tool, to evaluate construction
impacts on land, ecosystems, and water
Energy & Materials Flow & Cost Tracker (EMFACT), to
track materials, energy use, wastes, and costs
Greenhouse Gas Protocol, to quantify and manage GHG
emissions
MotorMaster + , to select energy efficient motors, and
Water Evaluation and Planning System (WEAP), to conduct
integrated water resource planning
Site investigation activities can disturb a significant
amount of land in order to gather the necessary data.
Project managers should consider technologies resulting
in limited subsurface intrusion and minimal land impacts:
Ground penetrating radar or other geophysical
methods can identify subsurface anomalies such as
USTs and buried drums without disturbing land.
DPT for soil and groundwater sampling do not result in
drill cuttings or excess soil waste and related IDW.
A wide range of direct sensing tools such as the LIE
sensor are now available to develop a nearly
continuous vertical profile of some volatile and semi-
volatile contaminants in the subsurface, both above and
below the water table.
Soil gas surveys are minimally invasive and can provide
relatively rapid and cost-effective information about the
presence, composition, and distribution of contaminants
in the vadose zone and water table.
A Sampling of Success Measures for
Site Investigation
Reduced fuel consumption and GHG emissions through
integrated planning of field activities
Increased use of solar energy-driven auxiliary equipment
and small devices
Reduced generation of wastewater from well drilling and
sampling
Reduced subsurface and ecosystem disturbance through
more use of advanced sampling technologies and
visualizing techniques
Fewer soil and groundwater samples needing offsite
laboratory analysis
References [Web accessed: 2009, December 30]
1 U.S. EPA; Principles for Greener Cleanups; August 27, 2009;
http://www.epa.gov/oswer/greencleanups
U.S. EPA; Green Remediation: Incorporating Sustainable
Environmental Practices into Remediation of Contaminated
Sites; EPA 542-R-08-002, April 2008;
http://www.cluin.org/greenremediation
3Interstate Technology & Regulatory Council; Technical and
Regulatory Guidance for the Triad Approach: A New Paradigm
for Environmental Project Management; December 2003;
http://www.triadcentral.org/
4U.S. EPA; Emission Facts: Average Carbon Dioxide Emissions
Resulting from Gasoline and Diesel Fuel; EPA420-F-05-001
Visit Green Remediation Focus online:
http://www.cluin.org/greenremediation
For more information, contact:
Carlos Pachon, OSWER/OSRTI (pachon.carlos@epa.gov)
U.S. Environmental Protection Agency
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