CE2100 Hazardous Waste Study Guide

4/22/25; Readings Masters and Ela (Chap. 6.6-6.7; 6.9)

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)

• referred to as the Superfund law → one of its key provisions is a $1.6 billion trust fund created from special crude oil and chemical company taxes

• enacted in 1980 in response to growing public pressure to do something about hazardous wastes

• reauthorized in 1986 and increased the trust fund to $8.5 billion (half of the money coming from petroleum and chemical companies, most from a special corporate environmental tax augmented by general revenues)

  • 1986 revisions are called the Superfund Amendments and Reauthorization Act (SARA)

• deals with mistakes of the past → already contaminated sites (inactive and abandoned hazardous waste sites)

• provides for the cleanup of inactive and abandoned hazardous waste sites

• does not involve usual regulations and permitting requirements

• focuses on identifying hazardous waste sites, preparing cleanup plans, and forcing responsible parties (RPs) to pay for remediation

  • RPs include historic owners/site operators, generators who disposed of wastes to the site, transporters who brought wastes to the site

• parties who are responsible for hazardous waste problems will be forced to pay the entire cost of cleanup

• allows EPA to deal with short-term emergency situations caused by actual/potential release of hazardous substances into the environment and long-term problems involving abandoned/uncontrolled hazardous waste sites (in which more permanent solutions are needed)

• examples of short-term removal actions

  • can be taken at any site where there’s an imminent threat to human health or environment

    • what might occur during a spill or fire

    • when wastes illegally disposed of are discovered, aka “midnight dumping”

  • EPA may take additional actions, like providing alternate drinking water supplies to local residents whose drinking water has been contaminated or temporarily relocating residents

• more complex and extensive problems that aren’t immediately life-threatening are handled under EPA’s remedial programs

• criticized for requiring the cleanup solution selection to provide a permanent solution to the contamination problem

  • some sites argue that temporary measures can cost very little while virtually eliminating health risks (rather than having a permanent site remediation project)

pg 340-343 of textbook

Toxic Substances Control Act (TSCA)

• authorizes EPA to regulate new chemicals as they are being developed and existing chemicals when there are new concerns for their toxicity

  • regulates the manufacture, use, and disposal of specific chemicals

• gives EPA the authority to:

  • gather information on the toxicity of particular chemicals

  • assess whether those chemicals cause unreasonable risks to humans and the environment

  • institute appropriate controls when deemed necessary

• covers the full lifecycle of specific chemicals (premanufacturing, manufacturing, importation, processing, distribution, use, and disposal)

• gives EPA authority to compile an inventory of existing chemical substances manufactured or imported for commercial uses

  • inventory contains information on over 60,000 chemical substances

  • entities that plan to manufacture/import new chemicals not in the inventory must give the EPA a notice 90 days in advance

    • notice must include the identity and molecular structure of chemical, estimate of the amount to be manufactured and its uses, byproducts, and data relating to the chemical’s health and environmental effects

    • new uses of chemicals that have already been approved must also be approved by the EPA

    • EPA may prohibit manufacturing/importing until there is adequate data showing that the chemical will not pose a risk to health or the environment

    • EPA may also make a manufacturer recall a substance that is found to present an unreasonable risk

• requires an exporter to notify EPA when certain chemicals are going to be exported → EPA then notifies the importing country’s government of the export and provides information on the chemicals (does not usually restrict exports)

pg 335-337 of textbook

Hazardous and Solid Waste Amendments (HSWA)

• 1984 amendments added to the Resource Conservation and Recovery Act (RCRA)

  • turning point in the relationship between Congress and EPA

  • returned policy control back to Congress (as EPA was not meeting congressional expectations)

• four main provisions

  • imposed severe restrictions on land disposal of hazardous waste

    • land disposal is banned unless EPA determines that for a particular site and type of waste that there will be no migration of hazardous constituents as long as the wastes remain hazardous

    • land ban automatically imposed if EPA does not follow through with such determination

    • new landfills and surface impoundments are required to have double liners, leachate collection systems, and groundwater monitoring facilities to ensure long-term containment

  • significantly reduced the level below which the rate of generation of hazardous waste was exempt from RCRA provisions

    • all liquid hazardous wastes are banned (because of groundwater contamination from landfills)

  • began the regulation of hundreds of thousands of leaking underground storage tanks (LUST)

  • closed loophole that allowed hazardous waste sites to be exempt from either RCRA or CERCLA regulations

pg 339 of textbook

Resource Conservation and Recovery Act (RCRA)

• originates from the 1965 Solid Waste Disposal Act, which was the first federal law to address how to safely dispose of household, municipal, commercial, and industrial reuse

• it passed in 1976 and was revised in 1980 and 1984

  • 1984 amendments are specifically referred to as the Hazardous and Solid Waste Amendments (HSWA), which expanded its scope in the land disposal

• controls new sources of hazardous waste

• provides guidelines for managing new and future hazardous substances

• regulates the generation, storage, transportation, treatment, and disposal of hazardous substances → deemed the most important law dealing with the management of hazardous waste

• its Subtitle C section regulates hazardous waste, while its Subtitle D section controls solid waste disposal

• Transportation, storage, disposal

  • key concept: hazardous substances must be properly managed from the moment they’re generated until their ultimate disposal (this step management is referred to as the cradle-to-grave approach)

  • under this act, the treatment, storage, and disposal (TSD) facilities that accept hazardous waste must obtain permits from the EPA

    • this process gives the EPA the power to enforce standards and requirements (eg the power to inspect facilities, bring civil actions against violators of the act’s provisions)

    • the act requires TSD facilities to acquire sufficient financial assurance mechanisms to ensure that the facility can be maintained after it closes

      • provision for 30 years of maintenance, security measures, and groundwater monitoring

pg 337-339 of textbook

How do CERCLA, TSCA, and HSWA differ from Resource Conservation and Recovery Act (RCRA)?

Difference between CERCLA and RCRA

• CERCLA deals with problems of the past (abandoned hazardous waste sites)

• RCRA attempts to prevent future problems

• pg 333 of textbook

Difference between TSCA and RCRA

• although both regulate the disposal of hazardous substances

  • TSCA deals with individual, specific chemicals (eg PCBs)

  • RCRA deals with combinations of chemicals contained in wastestreams

• pg 337 of textbook

Difference between HSWA and RCRA

• HSWA outlines the 1984 amendments to the RCRA and specifically expanded the RCRA’s scope in land disposal

• HSWA is part of the RCRA

• pg 339 of textbook

Hazardous wastes can be defined by what four characteristics?

• substance is hazardous if it possesses any of the following four characteristic attributes: ignitability, corrosivity, reactivity, or toxicity

Ignitable

• substances easily ignited and burn vigorously and persistently

• ex: volatile liquids (eg solvents), whose vapors ignite at relatively low temperatures (defined as 60 degrees Celsius or less)

Corrosive

• includes liquids with pH less than 2 or greater than 12.5 and substances capable of corroding metal containers

Reactive

• substances unstable under normal conditions

• can cause explosions and/or liberate toxic fumes, gases, and vapors when mixed with water

Toxic

• substances harmful or fatal when ingested or absorbed

• toxicity of a waste determined using an extraction test which simulates the expected leaching action that might occur (eg in a sanitary landfill)

• substance considered toxic if the extract from the test contains chemicals in concentrations greater than allowed

• EPA changed the extraction test procedure in 1990 from the EP Toxicity Test to the Toxicity Characteristic Leaching Procedure (TCLP) test

pg 334 of textbook

Cradle-to-grave management of hazardous substances is required by what act?

Resource Conservation and Recovery Act (RCRA)

pg 337 of textbook

What are the key elements of cradle-to-grave management?

based on the concept that hazardous substances must be properly managed from the moment they are generated until their ultimate disposal → transportation, storage, and disposal

1. Tracking System: manifest document accompanies any waste transported from one location to another

2. Permitting System: helps assure safe operation of facilities that treat, store, or dispose of hazardous wastes

3. System of controls and restrictions that govern the disposal of hazardous wastes onto or into the land

pg 337 of textbook

Who retains responsibility for the waste as its tracked?

the generator is ultimately responsible for the waste tracking system

• generators prepare a hazardous waste manifest that accompanies the waste, which identifies the type and quantity of waste, generator, transporter, and TSD facility where the waste is being shipped to

• one copy of the manifest is sent to EPA when the waste leaves the generator and another when the waste arrives at a TSD facility

• generator receives a copy of the manifest after the waste arrives at the TSD facility

pg 337 of textbook

What mass of hazardous waste is produced per person per year?

• more than one ton of hazardous waste per person per year to provide expected goods and services

pg 339 of textbook

What is the National Priorities List (NPL)?

• central to the Superfund process

  • second step of the Superfund remedial process → after site discovery and before remedial/investigation study (RI/FS)

  • established and maintained under CERCLA

• lists the sites eligible for federally financed remedial activities

• identifies the worst sites in the nation based on factors such as:

  • quantities and toxicity of wastes involved

  • exposure pathways

  • number of people potentially exposed

  • importance and vulnerability of the underlying groundwater

• risk assessment is used to rank potential sites in the list

pg 341 of textbook

How is liability assigned in CERCLA?

• parties who are responsible for hazardous waste problems will be forced to pay the entire cost of cleanup

• responsible parties (RPs) include:

  • historic owners / operators of the site

  • any generators who disposed waste at the site (legally or illegally)

  • transporters who brought wastes to the site

• three kinds of liability for costs of cleanup

  • retroactive

    • covers problems created before Superfund was enacted

  • strict

    • refers to the fact that liability does not depend on whether the RPs were negligent or diligent in their disposal practices

  • joint-and-several

    • if damages cannot be individually split by the RPs themselves, then each and every party is subject to liability for the entire cleanup cost

    • no matter when their contribution occurred, no matter how careful they were, and no matter how little an individual RP may have contributed to the overall problem, they can be liable for the entire cost of the cleanup

• EPA can use Superfund monies to clean up the site if RPs do not voluntarily perform the appropriate response actions

  • EPA may collect three times the cleanup cost from RPs

• some argue that it is unfair to be held responsible for disposal practices that were legal in the past

• others argue that it’s unfair that property owners are at risk for cleanup costs even if they were not responsible for contamination

pg 342 of textbook

What is the EPA’s current approach to Brownfields?

• Brownfields: abandoned, idled, or under-used industrial and commercial facilities where expansion or redevelopment is complicated by real or perceived environmental contamination

• In 1995, EPA launched the Brownfields Economic Redevelopment Initiative

  • effort to address some of the liability concerns and fairness issues of CERCLA and help revitalize communities affected by contamination

  • based on the belief that public fear of contamination and lender concerns for liability causes companies to leave brownfields in the urban core and head to greenfields outside the cities

  • aims to reverse unaddressed contamination, declining property values, and increased unemployment found in inner-city industrial areas

• key components of the initiative include:

  • removing eligible sites from the Superfund site tracking system, known as the Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS)

    • initial actions removed 27,000 sites out of the 40,000 being tracked

    • removing sites from CERCLIS conveys assurance that the EPA will no longer pursue Superfund action at these sites

  • clarification of liability issues that frequently case potential buyers and lenders to avoid contaminated properties

    • EPA will not take action against owners when hazardous substances enter the property from aquifers contaminated elsewhere (as long as the owner did not cause the problem or did not have a contractual arrangement with the polluter)

• focuses attention on risk-based corrective actions where the most feasible remediation technologies are combined with best management practices to provide cost-effective cleanup with compromising the protection of public health, water quality, and environment

pg 343 of textbook

What approaches can be used for land disposal of hazardous wastes?

HSWA provisions are Land Disposal Restrictions (LDRs), where land disposal includes the placement of hazardous waste in the following:

• landfills

  • designed as a modular series of 3D control cells

  • separate cells makes it possible to segregate wastes so only compatible wastes are disposed of together

  • arriving wastes placed in appropriate cell and covered at the end of each working day with a layer of cover soil

  • below the hazardous wastes is a double-liner system to stop the flow of liquids (leachate) from entering the soil and groundwater beneath the site

  • upper liner is a flexible-membrane lining (FML), which is usually made of plastic or rubber sheets

    • common plastics include PVC, HDPE, CPE

    • common rubber include CSPE and EPDM

    • thickness ranges from 0.25 mm to over 2.5 mm depending on the material chosen

  • lower liner is usually an FML, but recompacted clay that is at least 3 feet thick is also acceptable

  • leachate that accumulates above each liner is collected in a series of perforated drainage pipes and pumped to the surface for treatment

  • a low permeability cap is placed over the completed cells to reduce the amount of leachate formed by precipitation seeping into the landfill

  • includes monitoring facilities

• surface impoundments

  • excavated or diked areas used to store liquid hazardous wastes

  • storage is temporary unless impoundment is designed to eventually be closed as a landfill

  • cheap and wastes remain accessible, allowing some treatment to take place during storage

  • treatment technologies used include neutralization, precipitation, settling, and biodegradation

  • historically poorly constructed, monitored, and sited → principal source of contamination in a large number of Superfund sites

  • regulations require new surface impoundments to have two or more liners, leachate-collection system, and monitoring programs similar to those required for landfills

• waste piles

• injection wells

  • dispose of liquid hazardous wastes by forcing them underground through deep injection wells

  • required to extend below the lowest formation containing underground sources of drinking water to prevent underground drinking supplies from becoming contaminated

    • more than 700 meters below the surface

  • regulation for such systems fall under the Safe Drinking Water Act of 1974 (deals with underground drinking water supplies)

• land treatment facilities

• salt domes or salt bed formations

• underground mines or caves

• concrete vaults or bunkers, intended for disposal purposes

pg 355-357 of textbook

What are the major differences in design and management between hazardous waste landfills and MSW landfills?

Hazardous Waste Landfills

• multiple layers of liners

• multiple leachate collection systems

• stricter regulations

  • can only be located in certain areas / with respect to water sources

  • require information on exposure pathways and possible human exposure

  • no liquid in landfills at all

• more extensive monitoring and operational standards

MSW Landfills

• single liner

• single leachate collection system