603-pt – revision 4 – 04.20.08.usa
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Welcome to the International Right of Way Association’s Course 603 Understanding Environmental Contamination in Real Estate. 603-PT – Revision 4 – 04.20.08.USA. Introductions Who we are… What we do… Where we do it… How long we’ve been doing it… Our goals for the course. - PowerPoint PPT PresentationTRANSCRIPT
11
Welcome to the International Right of Way
Association’s Course 603
Understanding Environmental Contamination in Real Estate
603.PPT.R5.2015.08.14.0.0
22
Introductions
Who we are…What we do…
Where we do it…
How long we’ve been doing it…
Our goals for the course...
33
Objectives At the conclusion of the course,
you will be able to...
Recognize situations that have the potential for
site contamination
Identify common types of contamination
Discuss potential implications of contamination on the right of way and to the project
Present options to manage or remediate environmental contamination
44
Housekeeping
55
Schedule (1)
8:00 - 8:30 Introductions, Etc.
8:30 -10:00 Contamination and Contaminants
10:15 -11:15 Geology, Hydrogeology and Hydrology
11:15 - 12:00 Contaminant Movement
1:00 - 2:00 Contamination Discovery
66
Schedule (2)
2:15 - 3:15 Contaminations Affects on theRight of Way and to the Project
3:15 - 3:45 Options to manage or Remediate
Environmental Contamination
3:45 - 4:00 Summary and Review
4:00 - 5:00 Exam
77
Contamination and Contaminants
88
Definitions (1)
Contaminants are any physical,chemical, biological or radiological
substance or matter that has an adverse effect on air, water or soil.
99
Definitions (2)
Hazardous substances are anymaterials that pose a threat to
human health and/or the environment.
1010
Definitions (3)
A contaminated or hazardous waste site
is a site at which hazardous substances
occur at concentrations above background
levels and where assessment indicates
the site poses, or is likely to pose
an immediate or long-term hazard
to human health or the environment.
1111
Exercise No. 1 (1)
Please look at the sketch assigned to your group and with your group
identify property uses (e.g., gas station), the processes (i.e., activities or
conditions that might result in the presence and/or release of
contaminants or hazardous substances and the specific types of
contaminants or hazardous substances. Next, write the group’s project on the top of a sheet of
flip chart paper and list the property issues, processes and contaminants
or hazardous substances related to your project.
1212
Exercise No. 1 (2)
Auto wrecking yard: oils, grease, lubricants, paint chips, automotive fluids
Agricultural land: fertilizer and pesticide application, manure spreading, nitrates, pesticide residues
Dairy: cleaning chemicals, solvents, greases; possible routine or emergency fuel supply (oil?), milk, cream, asbestos containing materials (e.g., pipe elbows, boilers); mercury containing equipment, PCB containing equipment (e.g., light ballasts, capacitors)
Residential area 1930s: lead-based paint, asbestos containing materials (e.g., floor tiles); oil USTs or ASTs (depending on heating source in region), pesticides for insect infestation
Residential area 1970s: oil USTs, ASTs; possible but less likely ACM, LBP, hydraulic elevators, pesticides for insect infestation
1313
Exercise No. 1 (3)
Treated wood pole storage yard: residues from poles (depends on treatment), chromated copper arsenate, pentachlorophenol, creosote (i.e., PAH)
Residential area 1920s: lead-based paint, asbestos containing materials (e.g., floor tiles), oil USTs or ASTs (depending on heating source in region), imported fills
Highway and maintenance yard, vehicle garage: possible fuel storage (e.g., UST or ASTs, diesel, gasoline, MTBE, possible on-site heating oil storage), solvents, greases, lubricants storage/spills, road salt or other material storage, ACM in building materials, PCB containing equipment depending on building age
Sawmill and planning shop: wood waste, oils, greases, lubricants, possible tanks
1414
Exercise No. 1 (4)
Dump: leachate generation, seepage, (e.g., chloride, metals, organics, etc.)
Agricultural land: fertilizer and pesticide application, manure spreading, nitrates, pesticide residues
Farm house: septic system/tile bed, oil storage tank, farm dumps
Barn/barnyard: oils, lubricants, manure
Gas station: fuel storage; diesel, gasoline(i.e., BTEX, TPH, MTBE)
Small engine repair: storage use, disposal of chemicals, oils, greases, lubricants, solvents
1515
Exercise No. 1 (5)Dry cleaning: Perchlorethylene or other solvent usedfor cleaning (spill or disposal)
Delicatessen, corner store: ACM, LBP or PCB depending on building materials/equipment/age of building
Hardware store: miscellaneous spill or disposal of cleaning chemicals, solvents, greases; paints; building materials may contain ACM, PCB containing equipment
Residential area 1950s: lead-based paint, asbestos containing materials (e.g., floor tiles), oil USTs or ASTs (depending on heating source in region), imported fills
Residential area 1990s: possible oil USTs, ASTs,imported fills
Gas station: fuel storage/USTs, diesel, gasoline, MTBE, hydraulic lift
1616
Contamination Sources
Point Source
Non-Point Source
17
Point Source Contamination (1)
Point Source
• leaking storage tanks
• leaking buried pipes/transfer lines
• leaking lagoons
• landfill leachate see page, leaking buried drums
• spills
… a release from a small, specificand usually identifiable area
1818
Point Source Contamination (2)
Typical storage tanksat commercial facilities include USTs or ASTs for:
• fuel oil for heating systems
• diesel for emergency generators
• waste oil
• spill containment
UST = Underground Storage Tank
AST = Aboveground Storage Tank
1919
Point Source Contamination (3)
20
Point Source Contamination (4)
2121
Point Source Contamination (5)
2222
Non-Point Source Contamination
Non-Point Source
• fertilizer applications
• infiltration of ditch water
• sewage sludge applications
• particulate fallout
… a release over a wide area
2323
Hazardous or Designated Substances
• Asbestos containing material (ACM)
• Polychlorinated biphenyls (PCBs)
• Lead based paints
• Mercury containing equipment
• Urea formaldehyde foam insulation (UFFI)
• Radioactive sources/radon gas
2424
Asbestos Containing Material (1)
Popular from the 1900s to 1970s
• Floor tiles and linoleum
• Ceiling tiles
• Thermal mud insulation on pipe elbows
• Check boilers and boiler rooms
• Transit boards
• Asbestos cement drain piping
• Spray on (fire retardant) insulation
2525
Asbestos Containing Material (ACM) (2)
The condition of the ACM is important
• Poor or good repair?
• Friable or not friable?
2626
Polychlorinated Biphenyls (1)
Manufactured up to 1977
• Coolants and lubricants in electrical equipment (e.g., fluorescent light ballasts, fluid cooled transformers, capacitors)
2727
Polychlorinated Biphenyls (2)
2828
Lead-Based Paint
• Banned use in commercial housingby U.S. government in 1978
• Use of lead in paint fully phasedout in early 1980s
“good” condition, or “peeling”?
2929
Mercury Containing Equipment
Mercury used in switches, fluorescent light tubes and metal halide lights
Handling and disposal issue
3030
Urea Formaldehyde Foam Insulation
Used as insulation, sound insulation and air sealant
Used from the 1960s to about 1980
Health problem for some(formaldehyde off-gases)
Injected through1/2" - 2" holes
Look for plugs
3131
Radioactive Sources and Radon
• Radioactive sources include “older” smoke detectors and industrial sensors
• Radon gas - naturally occurring radioactive off-gas
from granite - sites with basements in locations with Exposed granite
3232
Why should we care?
• Drinking water impacts (e.g., health, aesthetic)
• Health hazards• Environmental impacts and resource
damage• Land use restrictions• Non-compliance• Legal liability• Material-handling requirements• Costs• Project impacts
3333
What makes a site “contaminated”?
• A relative term• Depends on a combination of:
- type of substance- concentration (e.g., ppm, ppb)- location (e.g., soil, groundwater, surface water)- current, planned or adjacent land/water use- jurisdiction and regulatory standards
3434
Concentration: Parts per million (ppm)
• Milligram per liter (mg/l) in water
• Milligram per kilogram (mg/kg) in soil- example: 4 drops in a 55 gallon barrel
3535
Concentration: Parts per billion (ppb)
• Microgram per liter (water)- ½ teaspoon in an Olympic sized
swimming pool (600,000 U.S. gallons)
• Microgram per kilogram (soils)
3636
Background Concentrations
• Many substances are present in “background” concentrations
• Naturally occurring or man - made- varies depending on location, geology
- Examples: Northeastern U.S. soils- arsenic <1 to 73 ppm- copper <0.6 to 495 ppm- lead <1.0 to 135 ppm
3737
Clean-up orRemediation Standards
• Established for certain contaminants
• Partly based on:- toxicity (i.e., potential to cause harm at concentration level)
- receptors of concern (e.g., people, organisms)
- potential intake or exposure pathway (e.g., skin contact, ingestion [e.g., eating, drinking), inhalation)
- background
• Generic standards are conservative (low!)
3838
Is the site clean?
• Misunderstood term
• Impossible to prove
• Can only compare concentrations in soil/water samples against standards/criteria
3939
Exercise No. 2Working with your partner, review the list of selected chemicals (Column A) and their concentrations (Column B) at a theoretical site. The future land use is residential. Compare each chemical’s concentration to the background concentration (Column C) and the remediation criteria of locations shown in Columns D through F.
Where the concentration exceeds applicable remediation criteria, draw a circle around that standard. Based on the comparison, indicate whether or not the site might be considered “contaminated.” Also, why are there such differences in some of the remediation criteria?
4040
Exercise No. 2
4141
Geology, Hydrogeologyand Hydrology
4242
Exercise No. 3
Working with your small group,solve the three puzzles.
4343
Geology
Geology is the science that dealswith the Earth, especially
as recorded in rocks.
4444
Hydrogeology
Hydrogeology is a branch of geology concerned with the occurrence, use
and functions of surface water and ground water.
4545
Hydrology (1)
Hydrology is the science that dealswith the properties, distribution andcirculation of water on and below
the Earth’s surface and inthe atmosphere.
4646
1. Condensation
2. Transpiration
3. Groundwater Flow
4. Evaporation
5. Water table
6. Evapotranspiration
7. Infiltration
8. Precipitation
4747
Subsurface
Overburden
Bedrock
Sand and Gravel
Gravel
Sand
Clay
Bedrock
Till
4848
PorosityPore space
Fractures
4949
Groundwater
5050
Groundwater Flow
Recharge Area Recharge Area
Discharge Area
5151
Groundwater Conditions
• Determined- by drilling boreholes
- installing monitoring wells
- measuring water levels
- conducting various tests
• Typically part of Phase II,
Environmental Site Assessment
5252
5353
Permeability
Permeability is a material’s capacity
to transmit water. . .
• An aquifer is a geological unit having a high permeability.
• As aquitard is a geological unit havinga low permeability.
5454
silt
clay
coarse sand
coarse sand
gravel
aquitard
aquifer
Geologic Units Hydrostratigraphic Units
Aquifer v. Aquitard
55
Types of Aquifers
Modified from Fetter, 1994
Confined aquifer – beneath an aquitardUnconfined aquifer - no aquitard above
Unconfined
Confined
Water table well
Artesian well
Flowing well
AquiferAquitard
56
5757
Exercise No. 4 (1)
Working in your Exercise No. 3 small groups, look at the three scenarios and answer the questions relating
to each scenario.
5858
Exercise No. 4 (2)
5959
Exercise No. 4 (3)
6060
Exercise No. 4 (4)
Upward
6161
Contaminant Movement
6262
Exercise No. 5 (1)
Each of the following three cross-sections or “slices” depicts a contaminant source, a release point, a simple geologic setting
and groundwater conditions.
With your partner, review each of the scenarios and determine where
you believe each of thecontaminants will flow.
63
Road salt storage pile
Water table
Groundwater flow direction
Sandy gravel
Release area
Clay
Ground surface
Road salt storage pile
Water table
Groundwater flow direction
Sandy gravel
Release area
Clay
Ground surface
Water table
Groundwater flow direction
Sandy gravel
Release area
Clay
Ground surface
A
BWater table
Groundwater flow direction
Sandy gravel
Underground storage tank (gasoline)
Clay
Release pointGround surface
Water table
Groundwater flow direction
Sandy gravel
Underground storage tank (gasoline)
Clay
Release point
Water table
Groundwater flow direction
Sandy gravel
Underground storage tank (gasoline)
Clay
Release point
Water table
Groundwater flow direction
Sandy gravel
Underground storage tank (gasoline)
Clay
Release pointGround surface
Water table
Groundwater flow direction
Sandy gravel
Solvent barrel (TCE)
Clay
Release point
Ground surface
Water table
Groundwater flow direction
Sandy gravel
Solvent barrel (TCE)
Clay
Release point
Ground surface
C
Septic systemor leach field
Groundwater flow direction
Cross-sectionSeptic systemor leach field
Groundwater flow direction
Cross-sectionSeptic systemor leach field
Groundwater flow direction
Cross-section
D
Road salt storage pile
Water table
Groundwater flow direction
Sandy gravel
Release area
Clay
Ground surface
Road salt storage pile
Water table
Groundwater flow direction
Sandy gravel
Release area
Clay
Ground surface
Water table
Groundwater flow direction
Sandy gravel
Release area
Clay
Ground surface
A
BWater table
Groundwater flow direction
Sandy gravel
Underground storage tank (gasoline)
Clay
Release pointGround surface
Water table
Groundwater flow direction
Sandy gravel
Underground storage tank (gasoline)
Clay
Release point
Water table
Groundwater flow direction
Sandy gravel
Underground storage tank (gasoline)
Clay
Release point
Water table
Groundwater flow direction
Sandy gravel
Underground storage tank (gasoline)
Clay
Release pointGround surface
Residual in soil
Possible floating gasoline if enough released
Water table
Groundwater flow direction
Sandy gravel
Solvent barrel (TCE)
Clay
Release point
Ground surface
Water table
Groundwater flow direction
Sandy gravel
Solvent barrel (TCE)
Clay
Release point
Ground surface
C
Possible DNAPL moving down along clay
Dissolved plume
Septic systemor leach field
Groundwater flow direction
Cross-sectionSeptic systemor leach field
Groundwater flow direction
Cross-sectionSeptic systemor leach field
Groundwater flow direction
Cross-section
D
As far as possible upgradient of septic field
Where to put water well?
Exercise No. 5 (2)
6464
Organic v. Inorganic
Organic compounds are biological. Contain carbon. (Methane, butane,acetone, toluene, acetylene, ethyl alcohol)
Inorganic compounds are mineral.(Ammonium, cadmium, chromium, lead, mercury)
6565
Important Propertiesof Contaminants
6666
LNAPL Light non-aqueous phase liquids
Lighter than water
If enough is released, it may ‘pancake’ on the
water table (e.g., gasoline)
6767
DNAPL Dense non-aqueous phase liquids
• Denser than water
• Sinks to lower permeability layers
• Moves along slope
• (e.g., Trichloroethylene [TCE] - crude oil coal tar components)
6868
Dissolved Contaminants
• Moves- by the transport of moving groundwater
- by “spreading” as it moves around soil grains, fractured rock
- slowly from high concentration to low concentration
• Net effect = dilution
69
Spill from Drum to Shallow Groundwater (Plan view)
x
x
x
x
Groundwater flow direction
At time of spill
Later
Even later
7070
Reactive Processes• Can change chemical or reduce its
concentrations in the environment- biodegradation
- biotransformation
- chemical transformation
- radioactive decay
- sorption
- ion exchange
- volatilization
- precipitation/dissolution
7171
The Break (1)
Marsh / Wetland
Creek5
0 60 7
0
80
A
RiverA
Crude Oil pipeline 3’ below grade
Pipeline
Break
7272
The Break (2)
Sand
Clay and Silt
Silt and fine
sand
Pipeline break
River Water table
A A’
7373
Exercise No. 6 (1)
Working in your Exercise No. 1small group, please revisit the sketch assigned to your group.
Please follow the additional explanations in your manual.
7474
Exercise No. 6 (2)
Possible groundwater contamination from the auto wrecking yard (due to oil spills, greases, automotive fluids, battery acids) and from the agricultural properties (fertilizers, animal wastes). The project, depending on the depth of excavation may impact the groundwater and may require the handling and disposal of contaminated soils.
7575
Exercise No. 6 (3)
Issues with the pole storage yard (potential handling of
contaminated soils during pipeline excavation).
If there are any prior releases or spills from the highway
maintenance yard, there may be an issue of handling contaminated groundwater during excavation.
Also, the 1920s residential buildings along the alignment may contain ACMs, LBPs, oil
tanks.
7676
Exercise No. 6 (4)
Leachates from the old municipal dump is a main concern. Issues may depend on the depth and number of excavations for tower footings.
7777
Exercise No. 6 (5)
Depending on the depth of excavation for the transit footings and the water table elevation, there may be several concerns. If there are any substantial release of PCE from the dry cleaners, DNAPL moving towards the alignment may be a concern. If any release of gasoline/diesel from the gas station, groundwater may move toward the alignment.
Also, the 1950s residential buildings along the alignment may contain ACMs, LBPs, oil tanks.
7878
Contamination Discovery
7979
Exercise No. 7
Please match the activity with the activity’s purpose.
8080
3.
6.
1.
2.
5.
4.
7.
Exercise No. 7
8181
Environmental Site Assessments
… an analysis of a specific parcel of real
property to identify environmental risk.
Phase I
Phase II
Phase III
8282
Phase I, Environmental Site Assessment (Phase I, ESA) (1)
• Preliminary environmental assessment stage
• Scope– historic data review – site reconnaissance– interviews with knowledgeable persons– report
8383
Phase I, Environmental Site Assessment (Phase I, ESA) (2)
• Identifies -potential environmental concern issues
- “Recognized Environmental Conditions”- the presence or likely presence of any hazardous substances or petroleum products on a property under conditions that indicate an existing release, a past release, or a material threat of a release of any hazardous substances or petroleum products into structures on the property or into the ground, groundwater, or surface water of the property
8484
Phase I, Environmental Site Assessment (Phase I, ESA) (3)
• Paper study
• Usually does not include samplingand testing
• May add on:- limited non-intrusive testing
- compliance components
8585
Phase I, Environmental Site Assessment (Phase I, ESA) (4)
• Timeline and Cost - usually requires 2 to 3 weeks (maybe longer)
to complete thoroughly
- costs variable; but usually $2500 to $4500- if the site has a complex, long history of use, apparent problems or issues, may require several months to prepare and cost several thousand dollars
• Not all Phase I ESAs are equal!
8686
Phase II, Environmental Site Assessment (Phase II, ESA) (1)
• Secondary stage of environmental assessment• Focused data collection on one or more issues • Usually involves:
- defining hydro geological conditions at site- collecting and analyzing soil, water, vapor- identifying concentrations of contaminants- in comparison to the criteria, is the site contaminated?
8787
Phase II, Environmental Site Assessment (Phase II, ESA) (2)
• Timeline and Cost (scope dependent)- 2 weeks to several months - costs varies from several thousand to several hundreds of thousands of dollars
• Testing
• May lead to:- no further action - further investigation- reporting to regulatory agency
8888
Testing Methods
Non-intrusive Intrusive
89
Non-Intrusive Sampling (1)
• Materials Sampling
- stockpile sampling of soil, fill or waste for characterization
- building materials sampling for asbestos, PCB, etc.
- sampling of drums or bins
- sampling of sludge in pits, sumps or drains
- can often be accomplished quickly and usually at relatively low cost
90
Non-Intrusive Sampling (2)
• Surface based geophysics- electromagnetic (EM), ground penetrating radar (GPR), micro-gravity
- most useful in “open area” settings
- can identify:
- USTs, pipes
- filled areas, conductive areas
- usually requires intrusive “ground truthing”
- may use to fine-tune drilling plan
91
Intrusive Sampling• Test Pits
- collect and analyze soil samples
- exterior of buildings
- more comprehensive examinations possible
- relatively inexpensive
• Sediment sampling• Soil Vapor Surveys
- for volatile organic contaminants (e.g., gasoline contamination)
- can be done in limited space environments
- suitable in some geologic settings
92
Testing Methods (1)
Geophysical survey
Auger drill rig
93
Testing Methods (2)
Hollow stem auger Excavator
9494
Testing Methods (3)
Drilling inside a building
Installing shallowmonitoring wells in
sandy conditions
95
Testing Methods (4)
Shallow test pit
Soil sample from sonic rig
9696
Testing Methods (5)
Soil samples in a split spoon sampler
Sampling amonitoring well
97
Exercise No. 8
Please match the objective andthe investigative method(s).
9898
3.
4.
1.
2.
5.
Exercise No. 8
99
Phase III, Environmental Site Assessment (Phase III, ESA) (1)
Remedial Investigation
• Purpose may include:
- defining the limits of contamination
- better understanding of site
- collecting additional detail for
- risk assessment
- evaluating remedial options
100
Phase III, Environmental Site Assessment (Phase III, ESA) (2)
Risk Assessment
• If cleaning up to meet conservative generic remediation criteria is too expensive• May consider risk assessment
- focus on certain contaminants- identify potential receptors- identify contaminant pathways
• Calculate risk
• Derive site specific remediation criteria
101
Phase III, Environmental Site Assessment (Phase III, ESA) (3)
Risk Assessment• Timeline and Cost
- several months
- costs tens of thousands of dollars or more depending on complexity
• May be worth investment to reduce eventual remediation costs
• May focus on part of site or whole site
• Acceptability/requirements vary by jurisdiction
102
Phase III, Environmental Site Assessment (Phase III, ESA) (4)
Remediation
• Options evaluation
• Remedial design
• Construction/implementation
• Monitor and test, if applicable
- is system performing as required?
• Potential long-term monitoring
103
Environmental Site Assessments
… an analysis of a specific parcel of real
property to identify environmental risk.
• Phase I
• Phase II
• Phase III
104
Contaminations Affects on the Right of Way and
to the Project
105
Elevated Rapid Transit Line
106
Potential Implications or Consequences on… (1)
Right of way and project costs
Project timeline
Project schedule
Regulatory requirements or obligations
Stakeholders
Legal actions
107
Legal Actions
• Comprehensive, Environmental Response, Comprehensive, and Liability Act (CERCLA)
• Superfund
• 1980
• Uncontrolled hazardous waste sites
• Potentially Responsible Party (PRP)
- clean up costs
- natural resource damage
108
Potentially Responsible Party (PRP) Types (1)
• Established by statute
• Owner and operator
- at the time of contaminant release
- current
- past
• Party who arranged for disposal
• Transporter or disposer
109
Potentially Responsible Party (PRP) Types (2)
• Established by courts- “innocent parties”
• Direct oversight, management or contractual relationship
- creditors - trustees in bankruptcy - successor corporations - corporate officers
110
Liability
• Strict
- knowingly or unknowingly
- with or without fault
• Joint and several
- all or part of costs
- former owners remain liable DEEP POCKETS
111
Purchaser Defenses
• Superfund Amendments and Reauthorization Act (SARA 1986)
• Innocent Land Owner- did not know- had no reason to know- made all appropriate inquiries
• Due diligence
112
Exemptions
• For agencies exercising eminent domain
• Before acquisition- release occurred prior to acquisition- no reason to know- made all appropriate inquiries
• After acquisition - must exercise due care- do not contribute to release
113
Potential Implications or Consequences on… (2)
Environment
Health and safety impacts
Right of way
Operations and maintenance
Insurance risks
114
Exercise No. 9 (1)
Please read the following scenarios and then with your partner
answer the questions.
115
Exercise No. 9 (2)
Scenario No. 1
Concerns may include:
Was any contaminated soil removed with the tanks?
Are there septic, hydraulic lifts in garage?
Are there any other tanks of concern?
What about piping or other structures?
What was the extent of groundwater contamination, if any?
What other chemicals may be stored on-site?
Is asbestos, mercury or PCB containing equipment on-site? If yes, how much?
116
Exercise No. 9 (3) Scenario No. 2
Concerns may include:
Has the contamination penetrated the water or sewer system?
Does it pose a hazard (e.g., confined space, flammability) to workers?
How far has the contamination migrated?
What action should the city take?
What legal action should the city take?
117
Options to Manage or Remediate Environmental
Contamination
118
Options
What are some clean up or remedial
options that you have heard of?
119
Typical Options
“Do nothing” Source removal
Source and/or plume control Combined methods
Institutional and engineering controls
120
Do Nothing
• In some cases, a valid environmentalmanagement option
• Often does not improve marketability,although this is changing
• Rarely accepted by lenders, insurers, regulators, unless site is monitored and risks are acceptable (e.g., Risk Management Approach)
121
Risk Management Approach
• Contamination managed on-site (in-situ)
• Site-specific risk assessment (SSRA) indicates acceptable risk under specified conditions and land use
122
Risk Management
• Likely will involve:
- institutional controls- deed or land use restrictions, covenants
- engineering controls
- long-term monitoring and maintenance
- contractual agreements
- provide financial security for on-going work
123
Site Specific Risk Assessment (SSRA) (1)
• Evaluation of environmental, human health and safety risk posed by contamination at a specific site
• May be used to develop site-specific investigation and remediation criteria
• Basis for generic criteria (but using VERY conservative assumptions)
124
Site Specific Risk Assessment (SSRA) (2)
• May indicate that site poses acceptable risk as is
• May indicate site poses acceptable risk with specified engineering controls (e.g., asphalt cap over shallow soil contamination, etc.)
125
In-situ• Treats source zone in place (in-situ)
• No soil removal
• Reduces mobility, toxicity or concentration of contaminants
• Often conducted where simple excavation is costly (e.g., demolition otherwise required to remove soil under buildings or other large structures)
126
• Highly dependent on geology
• Suitable beneath structures
• May require indoor air monitoring
• Usually requires a permit
Source Removal In-situ Treatment
127
In-situIn-situ remediation means to treat
the contamination on-site or in-place.
Ozone and oxygen spargingExcavation and on-site storage
Excavation/treatment and replaceBioremediation
Groundwater soil vapor recoveryPhytoremediation
EncapsulationThermal desorption
128
• Similar opportunities and constraints to simple excavation and disposal
• Soil may be treated on-site or off-site
• May be water management issues
• Disposal costs replaced by treatment costs (e.g., bioremediation piles, thermal desorption
In-situ: Excavation, Treatment and Replacement
129
In-situ: Soil Vapor Extraction• Withdrawal of soil vapors by vacuum pumps
• Use drilled wells or trenches
• Only useful for volatile compounds
- chlorinated solvents, petroleum products
• Highly dependent on geology
• Requires a permit
• May be time-consuming
130
In-situ: Physical/Chemical Treatment
• Injection of chemical oxidants, surfactants, or alcohols into source zone
- using drilled wells or trenches
- potassium permanganate for chlorinated solvents
- usually works quickly, but rarely removes 100% of problem
- requires full contact between injected chemicals and contaminants
131
In-situ: Biological Treatment
• Typically uses native bacteria to biodegrade
• Additives (e.g., nutrients, oxygen, bacteria) may be injected to enhance the process
• May be time-consuming
132
In-situ: Thermal Treatment
• Heating of soil using buried electrodes or steam injection
• Vapors are extracted and treated
133
In-situ: Encapsulation
134
In-situ: Permeable Treatment Walls
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In-situ: Hydraulic Methods
• Groundwater pumping and treatment
- re-inject surface-treated groundwater- dispose of treated groundwater to sewer
• May be coupled with physical barriers
- barrier walls, surface liners, etc.
• Permit may be required
• Time-consuming and rarely cost- effective
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In-situ: Combined Methods• Sites are often managed using a
combination of methods
• Reflects range of:
- contaminant concentrations, locations
- current or proposed land use
- geological/hydrogeological conditions
- other constraints
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Ex-situ
Ex-situ remediation means to removethe contamination from the site.
Excavation and off-site (ex-situ) disposal at a legally authorized site.
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• May be cost-effective for some contaminated sites if:
- relatively small volume
- non-hazardous material
- Accessible – without Impractical level of effort
Ex-situ: Excavation andSource Removal (1)
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• Permanent removal of issue from site
• May have to import “clean” material
• May be water management issues
• Cost may be significant
• On-site material handling/storage
• Suitable disposal site required
- must demonstrate acceptable soil quality
- potential for ongoing liability at disposal site
Ex-situ: Excavationand Source Removal (2)
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Ex-situ: Excavationand Source Removal (3)
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Institutional andEngineering Controls
• Deed notices, deed restrictions• Cumulative Effects Analysis – CEA’s,
well restriction areas
• Caps, covers, pavement, building slabs• Fencing• Signage
• O&M, recertification
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Brownfields• Defined
- real property, the expansion, redevelopment, or reuse of
which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant.
- abandoned or under-utilized
- contaminated
- have not been redeveloped due to remediation and liability cost concerns
• Environmental and economic opportunities
• Wide range of state and federal programs
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Brownfield Programs• Incentives can accelerate action:
- support letters - prospective purchaser agreements - deduct cleanup costs from taxes- limitation of liability - low interest loans- unified agency reviews (reduce redundancy
and confusion when multi-jurisdictional)- voluntary cleanup programs- grants for investigation and cleanup
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Voluntary Cleanup Programs
• Typically: - to restore low risk properties quickly
- responsible party pays
- proceeds at own pace
- in conformance with regulator processes and standards
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Exercise No. 10 (1)
Based on the contaminated site clean-up or remediation options discussed previously
plus any additional options that cometo mind, with your tablemates develop
a list of viable options to deal withthe following scenario.
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Exercise No. 10 (2)
Possible answers include: Capping of lead contamination; maintain and monitor cap Removing some of the lead contamination; off-site disposal at appropriate site, cap remainder, maintain and monitor cap Removing and disposing of all lead contamination at appropriate site Pumping to collect and treat groundwater
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Objectives Now, you are able to...
• Recognize situations that have the potential for site contamination
• Identify common types of contamination
• Discuss potential implications of contamination on the right of way and to the project
• Present options to manage or remediate environmental contamination
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Thank you
603-PT – Revision 4 – 04.20.08.USA