3. What is a Hazardous Waste?
A solid waste, or combination of solid wastes,
which because of its quantity, concentration, or
physical, chemical or infectious characteristics
may –
(a) cause or significantly contribute to an increase
in mortality or an increase in serious
irreversible, or incapacitating reversible illness;
or
(b) pose a substantial present or potential hazard
to human health or the environment when
improperly treated, stored, transported, or
disposed of, or otherwise managed.
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4. What is a Hazardous Waste?
EPA
By its presence on the EPA-developed lists
(b.c. they said so)
By evidence that the waste exhibits ignitable,
corrosive, reactive, or toxic characteristics.
Declared by Generator.
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5. Resource Conservation and
Recovery Act – RCRA (1976)
Establishes a “cradle to
grave” system of solid and
hazardous waste
regulations.
Defines wastes that are
regulated
Specifies requirements for
generators, transporters,
and treatment, storage and
disposal facilities (TSDFs).
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7. Comprehensive Environmental
Response, Compensation, and Liability
Act (CERCLA) - 1980
To provide a mechanism to clean up
contaminated sites and hold potentially
responsible parties (PRPs) accountable for
clean up costs
Deal with “past-sin”
CERCLA established a $1.6 billion Trust
Fund, known as Superfund.
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8. Comprehensive Environmental
Response, Compensation, and Liability
Act (CERCLA) - 1980
EPA can only conduct long term remediation actions
at sites that are on the National Priorities List (NPL),
which ranks the sites eligible for Superfund clean up
through Hazard Ranking System (HRS).
Remedial Investigation (RI)
Feasibility Study (FS)
Record of Decision (ROD)
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9. SARA - Emergency Planning and
Community Right-to-Know Act
Superfund amendments and
Reauthorization Act (SARA) of 1986
appropriated another $8.5 billion.
To create emergency response plans to
prepare for accidental chemical releases.
The EPA receives the Toxic Release
Inventory (TRI) reports with the
authority to inspect.
The public can know what types of
chemical are being released by
manufacturing facilities in their
communities.
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10. Sources of Hazardous Wastes
Industrial waste streams
Process waters
Used chemicals
Off-spec materials
Leaking storage tanks
Spills of products
Waste that were improperly
disposed
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11. Solutions to the Hazardous
Wastes Problems
1. Reduce amount generated
2. Promote waste exchange
3. Recycle useful components (energy,
metals)
4. Detoxify and neutralize liquid streams
5. Reduce volume
6. Destroy combustible waste
7. Stabilize and solidify sludges and ash
8. Properly engineered landfill
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12. Health
Effects of
Hazardous
Waste
Exposure
Release of HW to air, water, or land
Cause injury or death to a people, plants and animals, if:
a large amount is released at one time (acute
exposure)
a small amount is release many times at the same
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location (chronic exposure)
14. Risk
Assessment
Risk: Probability of exposure of individuals,
populations or ecosystems to toxic substances.
Risks can be lowered by reducing any
component of risk.
Risk assessment: Estimate of the severity and
likelihood of harm to populations or ecosystems
from exposure.
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15. Risk
Assessment
Risk assessment:
source assessments to identify hazard or
potential hazard
exposure assessment to identify actual or
potential recipient
dose-response assessment
risk characterization (numerical estimate)
Risk Management
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16. Risk Assessment – An example
When drinking water is disinfected with chlorine an
undesirable by-product, chloroform is formed.
What is the lifetime cancer risk for an adult
drinking water containing chloroform at a
concentration of 100 µg/L?
If the water supply for a city with 500,000 people
in it also drinks this water, how many extra cancers
can be expected as a result of this exposure?
Compare the extra cancers per year caused by
chloroform with the expected number of cancer
deaths from all causes.
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17. Site Remediation
Problem discovery
Identify the source
Removal of source
Remedial Investigation (site assessment)
extent of the plume
levels of concentrations
characteristics of the contaminants
characteristics of the matrices
Feasibility study
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18. Site Remediation
Remedial alternatives
cost
effectiveness
implementability
agency regulation
public acceptance
Prevent further plume
migration
Remediation
Monitoring, regulatory
compliance
Closure
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19. Hazardous Waste
Treatment
Soil Remediation
Soil vapor extraction
Soil washing
Solidification/stabilization
Bioremedaition
Other innovative technologies
On-site, off-site
In-situ, ex-situ
Physical
Groundwater Remediation
Chemical
Air stripping
Biological
Activated Carbon Adsorption
Thermal
Bioremediation
Disposal (landfill,
deep well injection)
Ion exchange
Soil/groundwater/air
Advanced oxidation process
(AOP)
Natural attenuation
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Others
