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
1
1
Introductions
Who we are…
What we do…
Where we do it…
How long we’ve been doing it…
Our goals for the course...
2
2
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
3
3
Housekeeping
4
4
Schedule (1)
5
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
5
Schedule (2)
6
2:15 - 3:15
Contaminations Affects on the
Right 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
6
Contamination and
Contaminants
7
7
Definitions (1)
Contaminants are any physical,
chemical, biological or radiological
substance or matter that has an
adverse effect on air, water or soil.
8
8
Definitions (2)
Hazardous substances are any
materials that pose a threat to
human health and/or
the environment.
9
9
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.
10
10
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.
11
11
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
12
12
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
13
13
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
14
14
Exercise No. 1 (5)
Dry cleaning: Perchlorethylene or other solvent used
for 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
15
15
Contamination Sources
Point Source
Non-Point Source
16
16
Point Source Contamination (1)
Point Source
… a release from a small, specific
and usually identifiable area
• leaking storage tanks
• leaking buried pipes/transfer lines
• leaking lagoons
• landfill leachate see page,
leaking buried drums
• spills
17
Point Source Contamination (2)
Typical storage tanks
at commercial facilities
include USTs or ASTs for:
• fuel oil for heating
systems
• diesel for emergency
generators
18
• waste oil
UST = Underground Storage Tank
• spill containment
AST = Aboveground Storage Tank
18
Point Source Contamination (3)
19
19
Point Source Contamination (4)
20
Point Source Contamination (5)
21
21
Non-Point Source Contamination
Non-Point Source
… a release over a wide area
• fertilizer applications
• infiltration of ditch water
• sewage sludge applications
• particulate fallout
22
22
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
23
23
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
24
24
Asbestos Containing Material (ACM) (2)
The condition of the ACM is important
• Poor or good repair?
• Friable or not friable?
25
25
Polychlorinated Biphenyls (1)
Manufactured up to 1977
• Coolants and lubricants in electrical
equipment (e.g., fluorescent light ballasts,
fluid cooled transformers, capacitors)
26
26
Polychlorinated Biphenyls (2)
27
27
Lead-Based Paint
• Banned use in commercial housing
by U.S. government in 1978
• Use of lead in paint fully phased
out in early 1980s
“good” condition,
or “peeling”?
28
28
Mercury Containing Equipment
Mercury used in switches, fluorescent light tubes
and metal halide lights
Handling and disposal issue
29
29
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 through
1/2" - 2" holes
Look for plugs
30
30
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
31
31
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
32
32
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
33
33
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
34
34
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)
35
35
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
36
36
Clean-up or
Remediation 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!)
37
37
Is the site clean?
• Misunderstood term
• Impossible to prove
• Can only compare concentrations
in soil/water samples against
standards/criteria
38
38
Exercise No. 2
Working 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?
39
39
Exercise No. 2
40
40
Geology, Hydrogeology
and Hydrology
41
41
Exercise No. 3
Working with your small group,
solve the three puzzles.
42
42
Geology
Geology is the science that deals
with the Earth, especially
as recorded in rocks.
43
43
Hydrogeology
Hydrogeology is a branch of geology
concerned with the occurrence, use
and functions of surface water
and ground water.
44
44
Hydrology (1)
Hydrology is the science that deals
with the properties, distribution and
circulation of water on and below
the Earth’s surface and in
the atmosphere.
45
45
1. Condensation
8. Precipitation
7. Infiltration
6. Evapotranspiration
2. Transpiration
5. Water table
3. Groundwater Flow
46
46
4. Evaporation
Subsurface
Sand and Gravel
Gravel
Sand
Clay
Bedrock
Till
Overburden
Bedrock
47
47
Porosity
Pore space
Fractures
48
48
Groundwater
49
49
Groundwater Flow
Recharge Area
Recharge Area
Discharge
Area
50
50
Groundwater Conditions
• Determined
- by drilling boreholes
- installing monitoring wells
- measuring water levels
- conducting various tests
• Typically part of Phase II,
Environmental Site Assessment
51
51
52
52
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 having
a low permeability.
53
53
Aquifer v. Aquitard
Geologic Units
Hydrostratigraphic Units
silt
aquitard
clay
coarse sand
aquifer
gravel
coarse sand
54
54
Types of Aquifers
Water table well
Unconfined
Artesian well
Flowing well
Aquifer
Confined
Confined aquifer – beneath an aquitard
Unconfined aquifer - no aquitard above
Modified from Fetter, 1994
55
56
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.
57
57
Exercise No. 4 (2)
58
58
Exercise No. 4 (3)
59
59
Exercise No. 4 (4)
Upward
60
60
Contaminant Movement
61
61
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 the
contaminants will flow.
62
62
Exercise No. 5 (2)
Road
salt
Road
saltstorage
storage
Release
point
Release
point
pile
pile
Ground
surface
Ground
surface
Possible
DNAPL moving
Release
Releasearea
area
down along
clay
Groundwater
flow
Groundwater
flow
direction
Groundwater
direction
Groundwaterflow
flow
direction
direction
CC
AA
Ground
Groundsurface
surface
Watertable
table
Water
Water
Watertable
table
Septic
Septic system
system
or
field
or leach
leach
field
Underground
Underground
storagetank
tank
storage
Releasepoint
point
Release
(gasoline)
(gasoline)
D
B
B
Residual in
soil
Solventbarrel
barrel
Solvent
(TCE)
(TCE)
Dissolved
plume
Clay
Clay
Cross-section
Cross-section
Groundsurface
surface
Ground
Watertable
table
Water
Groundwater
Groundwater
flow
flow direction
direction
Possible
floating Groundwater
Groundwaterflow
flow
gasoline if direction
direction
enough
released
Where to put
water well?
Sandy
Sandy
gravel
gravel
Sandy
Sandy
gravel
gravel
Clay
Clay
As far as
possible
upgradient of
septic field
Sandy
Sandy
gravel
gravel
Clay
Clay
63
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)
64
64
Important Properties
of Contaminants
• Solubility
Ability of a substance to dissolve
in a specified amount of solvent
• Miscibility
Ability of two liquids to mix together
• Specific Gravity
The density of a specific liquid relative to water
• Volatility
How quickly a substance forms a vapor
at a certain temperature
65
65
LNAPL
Light non-aqueous phase liquids
Lighter than water
If enough is released, it
may ‘pancake’ on the
water table (e.g., gasoline)
66
66
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)
67
67
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
68
68
Spill from Drum to Shallow
Groundwater (Plan view)
At time of spill
x
Groundwater flow direction
Later
x
x
Even later
x
69
Reactive Processes
• Can change chemical or reduce its
concentrations in the environment
- biodegradation
- biotransformation
- chemical transformation
- radioactive decay
- sorption
- ion exchange
- volatilization
- precipitation/dissolution
70
70
The Break (1)
Crude Oil
pipeline 3’
below grade
River
Creek
Pipeline
Break
71
71
Marsh /
Wetland
The Break (2)
Pipeline
break
A
Silt and
fine
sand
River
Sand
Clay
and Silt
72
72
A’
Exercise No. 6 (1)
Working in your Exercise No. 1
small group, please revisit the
sketch assigned to your group.
Please follow the additional
explanations in your manual.
73
73
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.
74
74
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.
75
75
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.
76
76
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.
77
77
Contamination Discovery
78
78
Exercise No. 7
Please match the activity with
the activity’s purpose.
79
79
Exercise No. 7
3.
6.
1.
2.
5.
4.
7.
80
80
Environmental Site Assessments
… an analysis of a specific parcel of real
property to identify environmental risk.
Phase I
Phase II
Phase III
81
81
Phase I, Environmental Site
Assessment (Phase I, ESA) (1)
• Preliminary environmental
assessment stage
• Scope
–
–
–
–
82
historic data review
site reconnaissance
interviews with knowledgeable persons
report
82
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
83
83
Phase I, Environmental Site
Assessment (Phase I, ESA) (3)
• Paper study
• Usually does not include sampling
and testing
• May add on:
- limited non-intrusive testing
- compliance components
84
84
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!
85
85
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?
86
86
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
87
87
Testing Methods
Non-intrusive
88
88
Intrusive
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
89
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
90
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
91
Testing Methods (1)
Geophysical survey
Auger drill rig
92
Testing Methods (2)
Hollow stem auger
Excavator
93
Testing Methods (3)
Installing shallow
monitoring wells in
sandy conditions
Drilling inside a
building
94
94
Testing Methods (4)
Shallow test pit
Soil sample from sonic rig
95
Testing Methods (5)
Soil samples in a
split spoon sampler
96
Sampling a
monitoring well
96
Exercise No. 8
Please match the objective and
the investigative method(s).
97
Exercise No. 8
3.
4.
1.
2.
5.
98
98
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
99
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
100
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
101
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
102
Environmental Site Assessments
… an analysis of a specific parcel of real
property to identify environmental risk.
• Phase I
• Phase II
• Phase III
103
Contaminations Affects
on the Right of Way and
to the Project
104
Elevated Rapid Transit Line
105
Potential Implications or
Consequences on… (1)
Right of way and project costs
Project timeline
Project schedule
Regulatory requirements or obligations
Stakeholders
Legal actions
106
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
107
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
108
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
109
Liability
• Strict
- knowingly or unknowingly
- with or without fault
• Joint and several
- all or part of costs
- former owners remain liable
DEEP POCKETS
110
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
111
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
112
Potential Implications or
Consequences on… (2)
Environment
Health and safety impacts
Right of way
Operations and maintenance
Insurance risks
113
Exercise No. 9 (1)
Please read the following scenarios
and then with your partner
answer the questions.
114
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?
115
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?
116
Options to Manage or
Remediate Environmental
Contamination
117
Options
What are some clean up or remedial
options that you have heard of?
118
Typical Options
“Do nothing”
Source removal
Source and/or plume control
Combined methods
Institutional and engineering controls
119
Do Nothing
• In some cases, a valid environmental
management 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)
120
Risk Management Approach
• Contamination managed on-site (in-situ)
• Site-specific risk assessment (SSRA)
indicates acceptable risk under specified
conditions and land use
121
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
122
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)
123
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.)
124
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)
125
Source Removal
In-situ Treatment
• Highly dependent on geology
• Suitable beneath structures
• May require indoor air monitoring
• Usually requires a permit
126
In-situ
In-situ remediation means to treat
the contamination on-site or in-place.
Ozone and oxygen sparging
Excavation and on-site storage
Excavation/treatment and replace
Bioremediation
Groundwater soil vapor recovery
Phytoremediation
Encapsulation
Thermal desorption
127
In-situ: Excavation, Treatment
and Replacement
• 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
128
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
129
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
130
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
131
In-situ: Thermal Treatment
• Heating of soil using buried
electrodes or steam injection
• Vapors are extracted and treated
132
In-situ: Encapsulation
133
In-situ: Permeable Treatment Walls
134
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
135
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
136
Ex-situ
Ex-situ remediation means to remove
the contamination from the site.
Excavation and off-site (ex-situ) disposal
at a legally authorized site.
137
Ex-situ: Excavation and
Source Removal (1)
• May be cost-effective for some
contaminated sites if:
- relatively small volume
- non-hazardous material
- Accessible – without
Impractical level of effort
138
Ex-situ: Excavation
and Source Removal (2)
• 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
139
Ex-situ: Excavation
and Source Removal (3)
140
Institutional and
Engineering Controls
• Deed notices, deed restrictions
• Cumulative Effects Analysis – CEA’s,
well restriction areas
• Caps, covers, pavement, building slabs
• Fencing
• Signage
• O&M, recertification
141
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
142
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
143
Voluntary Cleanup Programs
• Typically:
- to restore low risk properties quickly
- responsible party pays
- proceeds at own pace
- in conformance with regulator processes
and standards
144
Exercise No. 10 (1)
Based on the contaminated site clean-up or
remediation options discussed previously
plus any additional options that come
to mind, with your tablemates develop
a list of viable options to deal with
the following scenario.
145
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
146
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
147
Thank you
148
603-PT – Revision 4 – 04.20.08.USA