Site Characterization for
Site Remediation
Presented to:
MWCC Conference 2016
Tan-Tar-A Resort
Lake of the Ozarks, MO
July 10-12, 2016
Derek Ingram, P.E., R.G., P.G
Do it Right, Do it once
Agenda
▪ Common Occurrence
▪ Old Thinking
▪ New Thinking
– Objectives and Criteria
– Investigation
– Bench Testing
– Evaluation and Design
▪ Remedial Failure Causes
▪ Summary
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The Common Occurrence
▪ Characterization and RI/FS report completed
▪ Environmental impact of COCs have been delineated
laterally and vertically
▪ Corrective Action Plan is the next step
▪ The stand-by option is pre-selected based on “this is what
we do for these sites” mentality
▪ Or……as alternatives are being evaluated site-specific
parameters are not available and default values are utilized
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The Potential Results
▪ Technologies that are better fit for the site conditions are
never considered
▪ Areas and volumes of non-risk material are remediated
▪ Areas and volumes of risk material are not addressed
▪ Default values present a non-realistic perception of the site
conditions and the associated risk
▪ The focus of addressing the site issue is overshadowed by
the “want” to detail site conditions
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Definition
What is “characterization”?
In an environmental remediation operation, the process of
defining and analyzing the contaminants and media of a site to
determine the nature and extent of contaminants present
It has three primary components:
▪ Background/history/records check
▪ Sampling/surveying
▪ Groundwater monitoring
However, the definition doesn’t provide anything on defining and
analyzing to what baseline….in most cases, it is assumed to be
conservative….but it needs to be established and can be flexible
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Old Thinking: RI/FS à Remedial Design
Initial RI
Data Gap Analysis
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Environmental Reality
We are nearly 50 years into environmental regulations
▪ Rarely do we go into a project “blind”
–
–
–
–
Multiple ESA’s
Detailed site histories
FOIA on adjacent properties
Owners, developers, bankers, neighbors, lawyers, employees,
action groups, regulators…….all have a piece of the pie.
– Liability is a line item on the financial reports….reserves
– Risk, action levels, and remedial approaches have become part of
a companies policies and procedures …. BUT may not be in
writing
So why approach projects under a 1990’s structure?
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So why approach projects under a 1990’s
structure?
▪ It’s what we know …..template
▪ Regulations are rigid…..little to no flexibility
▪ Change requires justification….how to present/review
▪ Consultants consult and remediators remediate …..difficult
for some to transition a project to the next step
▪ There is “never” enough data…data contradicts data
▪ The big picture is overshadowed by the
detail….engineer/scientist/geologist mentality
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General Statement
The end goal of environmental projects is closure.
True or False?
False:
Depends on the objective of the responsible party……many other options
depending on the primary driver
▪ Compliance ….meet minimum requirements (active facility)
▪ Financial ….spread costs over years
▪ Transfer ….await new owner/party (such as developer)
▪ Partial Remediation ….such as offsite only
▪ Risk ….what is the greatest liability?
▪ Legal ….other PRPs? Is it my problem? Did I cause it? Was it disclosed? Is
there a true risk?
▪ Enforcement or “non-enforcement”….is big brother concerned or even capable?
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New Thinking: Integrated Remedial Strategy
Define Objective
Define Criteria
• Depends on
sensitivity of
receptors,
regulations, etc.
• Site Closure?
• Set reasonable
criteria to achieve
goals
• Incorporate nonremediation
approaches
• Schedule
Remedial
Investigation
• Focus RI to get
data that support
goal / criteria
Feasibility Study
Remedial Design
• Field Data to
support design,
bench, pilot study
• Choosing
technology (or
hybrids) to meet
goals
• May be nonremediation
approaches
Have sights set on objective at the start, incorporate into every phase
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DefiningaReasonableObjective
Difficult or cost-prohibitive to achieve
– Stringent / low numerical standards for soils
– MCL’s in groundwater
– Remedial goals at every monitoring point
More reasonable goals
– Contaminant mass reduction
– Reduction in groundwater concentrations
– Visible NAPL reduction / reduce NAPL migration
– Average concentrations with a maximum not to exceed (ex. 10x)
– Point of compliance (property boundary); # of points
– Incorporate risk assessments to establish site-specific targets
– Design for collection of data specific for technical impracticality
demonstration
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DefiningReasonableCriteria
▪ Schedule
▪ Non Remediation Options
– Buffers
– Risk Assessments
– Zoning
▪ Liability Acceptance
▪ Funding
▪ Community Acceptance
▪ Regulatory Acceptance
KEY CONCERN: The “reasonable” aspects must take into
account the ability of the company to remain viable….stay in
business
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RemedialInvestigation
Focus RI to get data that support goal / criteria
▪ If excavation, collect data to define removal area without
need for confirmation sampling…..pre-approved within the
CAP
▪ What default values can I make site-specific values? How do
they affect my evaluation?
▪ Collect data to perform anticipated treatability studies
▪ Based on other projects…..what were my data gaps?
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Additional Evaluation Data Considerations
Beyond typical logs and lab results
▪ NAPL
– density/specific gravity; viscosity; TPH; disposal profile criteria
– NOTE: NEVER EVER define impact as a “source” or “product” until
analytical data is obtained (unless within a known holding structure)
▪ Soils
– Non-target compounds in 10% to 20% of samples randomly across site
(dosing ratios)
– TPH and toc/foc from each strata
– Geotechnical
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Additional Evaluation Data Considerations
▪ Groundwater
– Field parameters of DO, ORP (typical are pH, temperature, conductivity,
turbidity)
– Alkalinity, sulfate, dissolved and total iron/manganese
– From a subset: nitrate/nitrite, TDS, TSS, COD, bacteria standard plate
count
▪ Hydrogeologic
– For each strata: hydraulic conductivity, gradient, average linear velocity
– Bulk density and effective/total porosity
– Vertical gradient
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Example Investigation Approaches that Affect Design
▪ Well screens across multiple strata or very lengthy screens in a single strata
– Fail to allow for an understanding of site conditions
– Create potential cross-contamination pathways
– Have within themselves preferential path flow
– Can provide diluted samples
– Well clusters of varying depth provide usable data
▪ Collection of only high PID samples
– Gives the perception of “thicker” than present zones of impact
– Vertical and zone delineation is as important as lateral delineation
▪ False emphasis on PID readings
▪ Limiting analysis to a defined list of COCs
▪ No consideration given to trend analysis
– Often the correlation between ups and downs is key to addressing the issue
▪ False emphasis on PID readings
▪ Elevated Reporting Limits
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Keys to Evaluation and Design
▪ Consider and understand scavengers in addition to COCs
– metals, carbonates, nitrites, nitrates, sulfides, sulfates, foc, non-target
contaminants, etc…greatly affect consumption demand
▪ DO NOT IGNORE cumulative conditions
▪ For metals, it may not be the concentration, but often is the form….
▪ Failure is not always the wrong technology but often a failed understanding of the
usage
▪ Establish a cost/volume scale ($/cy or $/ton) to compare approaches and
technologies
▪ Must consider and design for treatment of degradation chain in
addition COCs and scavengers
– may create a secondary situation of equal, greater, or less
concern? Examples: vinyl chloride, pH, solubility
– Important to know baseline conditions
– Metals story……
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Some Keys to Evaluation and Design
Technical evaluation
– Consider and screen the array of potential
technologies
Bench testing– “DESIGN TOOL”
– Obtain demand criteria
– Lesser need for cohesive soils; reactant
dispersion and contact higher priority
– Samples can be collected during initial
evaluation as holding times are less crucial
Pilot testing
– Obtain site condition performance criteria
– Defines multiple application
Field scale
– Implement field pilot to full-scale
Critical for Accurate Cost To Closure Determination
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Concentration is as Important as Contaminant
▪ Multiple technologies are often the most feasible approach
– Do not assume “one size fits all” …….. Every technology has a wheelhouse
– Usage of multiple technologies reduces costs and utilizes a best fit
▪ Mother nature itself is the greatest remedial tool…..learn how to use
it.
– Degradation is constantly occurring, but sometimes a little help will do a
lot…. words of Scotts® “FEED IT, JUST FEED IT”
▪ WHY do we assume that we magically drill in the highest levels of
contamination?
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Cost Effective “Sweet Spot” for Organic Soil
Remediation Technologies
ContaminationonSoil
Technology
FreeFlowing PoreFilled
Product
Product
>10,000
mg/Kg
>1,000
mg/Kg
>100mg/Kg
>1mg/Kg
<1mg/Kg
Excavation
ExtractionandEnhancedExtraction
SoilVaporExtraction(SVE)
InSituChemicalOxidation(ISCO)
InSituChemicalReduction(ISCR)
InSituBioremediation(ISB)
AirSparging(AS)
NaturalAttenuation
ThermalEnhancements
ThermalenhancementscouldapplytoseveraltechnologiesincludingSVEandbeapplicableforhigherconcentrationsofcontamination.
Tableisintendedtorepresentthebestuseofatechnology.Mosttechnologiesmayhavebenefitinotherconditions.
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Cost Considerations
▪ Data gap mobilizations are expensive
▪ Collection during an initial investigation is inexpensive
▪ In relative terms, laboratory analysis for the additional
parameters is cheap
▪ Remediation is more expensive than investigation…..having
the applicable data for a better defined design will save in
overall costs
▪ ANOTHER CONSIDERATION
–Multiple boring locations increase concern for vertical
contamination
–Provide for preferential pathways
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Common Remedial Failure Causes
▪ Underestimating contaminant mass
– Bidders often low ball due to reduce “initial” cost … compare lb/lb or $/cy
and ask why?
– Scavengers
▪ Not addressing contaminant mass distribution
▪ Not identifying “Contact Limitations”
– Geology and/or chemical interactions that can impact ability to establish
contact with contaminants
▪ Failure to adjust to changing site conditions
The consequences of not fully conducting or understanding the evaluation
process:
– Recontamination
– Rebound
– No apparent effect
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Which Would You Cross?
State of the Practice
a.k.a. “should hold…”
State of the Art
a.k.a. “designed to hold”
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Summary
▪ Defining objectives and criteria early in the project is key
▪ Time is money; reaching the objective quickly reduces costs
▪ Understand and address “scavengers”
▪ Be prepared to account for changing site conditions
(approach may require phased and/or differing
technologies)
▪ Without a complete evaluation, the end result is often the
design result……..but not the anticipated result
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Thank You! Questions?
Derek D. Ingram, P.E., R.G, P.G.
([email protected])
XDD Environmental
(800) 486-3575
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www.xdd-llc.com