Dec 3 haz waste
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Transcript of Dec 3 haz waste
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Introduction
Definitions Sources Problems Regulations Risk Assessment Site Assessment Hazardous Waste Treatment Groundwater/soil remediation
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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.
What is a Hazardous Waste?
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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.
What is a Hazardous Waste?
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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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Resource Conservation and Recovery Act – RCRA (1976)
Uniform Hazardous Waste Manifest UST regulations Landfill regulations Hazardous and Solid Waste Amendments (HSWA) – 1984.
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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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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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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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Industrial waste streams Process waters Used chemicals Off-spec materials Leaking storage tanks Spills of products Waste that were improperly disposed
Sources of Hazardous Wastes
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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
Solutions to the Hazardous Wastes Problems
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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
location (chronic exposure)
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Health Effects of Hazardous Waste Exposure
Exposure considerations Who? How? At what concentration? For how long? How often? Actual dosage?
Exposure pathways Inhalation Ingestion Dermal contact
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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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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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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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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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Site Remediation
Remedial alternatives cost effectiveness implementability agency regulation public acceptance
Prevent further plume migration Remediation Monitoring, regulatory compliance Closure
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Hazardous Waste Treatment
On-site, off-site In-situ, ex-situ Physical Chemical Biological Thermal Disposal (landfill, deep well injection) Soil/groundwater/air Natural attenuation
Soil Remediation Soil vapor extraction Soil washing Solidification/stabilization Bioremedaition Other innovative technologies
Groundwater Remediation Air stripping Activated Carbon Adsorption Bioremediation Ion exchange Advanced oxidation process (AOP) Others
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Liquid Injection Incinerator
Rotary kiln with vertical secondary combustion chamber
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Soil Vapor Extraction (SVE)
Auger/caisson systems and injector head systems
In Situ Vitrification (ISV)
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Bioremediation
Soil Washing
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Packed tower Air Stripper
Advanced Oxidation Process (AOP) - a typical UV/H2O2 system
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Activated Carbon Adsorbers
Biological Treatment