BIO320 CHAPTER 19

1. 19-1
ENVIRONMENTAL
SCIENCE
A Study of Interrelationships
15th Edition
Environmental Regulations :
Hazardous substances and wastes
Chapter 19
©2019 McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction
or further distribution permitted without the prior written consent of McGraw-Hill Education.

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Outline (1 of 2)
19.1 Hazardous and Toxic Materials in Our
Environment
19.2 Characterizing Hazardous and Toxic
Materials
19.3 Controlling Hazardous Materials and
Waste
19.4 Managing Health Risks Associated with
Toxic Substances
Source: DOE

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Outline (2 of 2)
19.5 How Hazardous Wastes Enter the Environment
19.6 Hazardous-Waste Dumps- Regulatory Response
19.7 Hazardous-Waste Management Choices
19.8 Toxic Chemical Releases
19.9 International Trade in Hazardous Wastes
19.10 Nuclear Waste Disposal

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19.1 Hazardous and Toxic
Materials in Our Environment
Our modern technological society makes use of a large
number of substances that are hazardous or toxic.
At sites around the world, accidental or purposeful releases
of hazardous and toxic chemicals are contaminating the
land, air, and water.
Governments and international agencies set rules and
standards to protect the health and safety of people.

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The Life Cycle Of Toxic Substances

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19.2 Characterizing Hazardous
and Toxic Materials
Terms are incorrectly used interchangeably.
• Toxic commonly refers to a narrow group of substances that
cause human injury or death.
• Hazardous is a broader term; it refers to all dangerous materials
that create a human health or environmental problem.

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Identifying Hazardous Materials
Different organizations and government agencies have
differing definitions of what is hazardous.
The U.S. Department of Transportation (DOT) lists several
kinds of hazardous materials.

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DOT Hazardous Materials List
Explosives
• Materials that cause a rapid
release of gas and heat
Gases
• May be flammable,
nonflammable, or toxic
Flammable liquids
Flammable solids
Oxidizing substances and
organic peroxides
• Substances that release oxygen
that enables or enhances the
burning of materials
Poisonous (toxic) materials
and infectious substances
• Infectious substances may include
organisms or their products that
can cause disease
Radioactive material
• Materials that give off
ionizing radiation
Corrosives
• Materials that cause damage to
human skin
Miscellaneous dangerous
goods

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Hazardous Waste—A Special Category
of Hazardous Material (1 of 2)
Hazardous substances or hazardous materials are
those that can cause harm to humans or the environment.
The EPA defines hazardous materials as having one or
more of the following characteristics:
• Ignitability (Fire hazard)
• Corrosiveness (Corrodes material)
• Reactivity (Explosiveness)
• Toxicity (May release toxins)
Some hazardous materials, such as gasoline, fall into
several categories.

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Hazardous Waste—A Special Category
of Hazardous Material (2 of 2)
Hazardous wastes are by-products of industrial, business,
or household activities for which there is no immediate
use.
• They must be disposed of in an appropriate manner.
• There are stringent regulations pertaining to production, storage, and
disposal.

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Common Materials Can Produce
Hazardous Wastes

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19.3 Controlling Hazardous
Materials and Waste
To regulate the use of toxic and hazardous substances and
the generation of toxic and hazardous wastes, most
countries draw up a list of specific substances that have
been scientifically linked to adverse human health or
environmental effects.

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Laws and Regulations
“Command and control” methods of governmental
regulations began with the development of the EPA and
OSHA in 1970.
When dealing with past pollution events, governments must
assess who will pay for cleanup of hazardous substances or
wastes that enter the environment.
• The Potentially Responsible Party (PRP) will have to pay for dealing
with the remediation of the site once hazardous substances/wastes
are found in the environment.

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Voluntary Standards (1 of 2)
Some voluntary industry standards have been developed
and have been incorporated into federal acts.
ASTM International Phase I Environmental Site
Assessment standard E-1527 is an example of a voluntary
standard which involves prior assessment before beginning
a project.

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Voluntary Standards (2 of 2)
The International Organization for Standardization has
a standard for environmental management systems
known as ISO 14000.
• Many organizations and corporations seek ISO 14000 certification
as a way to indicate that they are controlling their environmental
impact and improving their environmental performance.

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19.4 Managing Health Risks Associated
with Toxic Substances (1 of 3)
Acute vs. Chronic Toxicity
• Effects of massive doses at once (acute toxicity) and small doses
over time (chronic toxicity) differ.
• Chronic toxicity is much harder to detect as effects may not surface for
long periods of time.
Synergism
• Assessing the effects of chemical mixtures is also problematic.
• Most toxicity studies focus on a single compound.
• Synergism is the potential of relatively harmless individual compounds to
become highly toxic and do great damage when combined.

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19.4 Managing Health Risks Associated
with Toxic Substances (2 of 3)
Persistent pollutants remain in the environment,
essentially unchanged, for long periods.
• Most are human-made.
• Synthetic chemicals are part of our food, transportation, clothing,
building materials, home appliances, medicine, recreational
equipment, and many other items.
• DDT is a persistent pollutant.
• Polychlorinated biphenyls (PCBs) are also persistent.

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19.4 Managing Health Risks Associated
with Toxic Substances (3 of 3)
Nonpersistent pollutants do not remain for a long period
and are often biodegradable.
Many toxic organic materials can be destroyed by
decomposer organisms.
• Organophosphates decompose in several weeks.
• They do not accumulate in food chain.

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Setting Exposure Limits (1 of 2)
Nearly all substances are toxic in sufficiently high doses.
• The question is, At what dose does a chemical become a hazard?
There is no easy way to establish acceptable levels.
Several government agencies set limits for different
purposes:
• PEL—Permissible Exposure Limits
• STELs—Short Term Exposure Limits
• TWA—Time Weighted Average
• CL—Ceiling Limit

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Setting Exposure Limits (2 of 2)
People can be exposed in three ways:
• Inhalation
• Consumption
• Absorption
Typically the regulatory agency will determine the level of
exposure at which none of the test animals is affected
(threshold level) and then set the exposure level lower
to allow for a safety margin.
• Even when concentrations are set, they may vary considerably
from country to country.

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19.5 How Hazardous Wastes
Enter the Environment
Businesses and industries are highly regulated.
Individual citizens are becoming more important as
sources of hazardous waste releases.
Hazardous wastes enter the environment in several ways:
• Evaporation
• Spills, leaks, or purposeful releases
• Dumping or storing on land
• Improper labeling and recordkeeping

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19.6 Hazardous-Waste Dumps-The
regulatory response
Prior to RCRA in 1976,
hazardous waste was
essentially unregulated.
• Hazardous wastes were simply
buried or dumped.
• Sites were typically located
convenient to the industry and were
often in environmentally sensitive
areas.
• In North America alone, there are
over 25,000 abandoned or
uncontrolled sites.

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Resource Conservation and
Recovery Act (RCRA) (1 of 2)
Under RCRA, substances are considered toxic or
hazardous if they:
• Cause or significantly contribute to an increase in mortality or an
increase in serious irreversible, or incapacitating reversible, illness;
or pose a substantial present or potential hazard to human health
or the environment when improperly treated, stored, transported,
disposed of, or otherwise managed.

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Resource Conservation and
Recovery Act (RCRA) (2 of 2)
U.S. Resource Conservation and Recovery Act of 1976
(RCRA):
• Gave the EPA the responsibility for regulating hazardous waste.
• Created the “cradle-to-grave” concept of hazardous waste
management by regulating generators, transporters, and Treatment
Storage and Disposal Facilities (TSDF) as well as underground
storage tanks (USTs) and petroleum products.
• This act also defined toxic and/or hazardous waste by using the
terms listed and characteristic waste.

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RCRA Requirements

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Resource Conservation and
Recovery Act (RCRA)
Several kinds of waste are specifically exempt by law from
RCRA regulation:
• Household hazardous waste
• Agricultural waste that is returned to the soil
• Mining overburden and processing waste
• Wastes associated with oil and gas exploration and production
• Ash from burning coal
• There have been efforts to change the law regarding coal ash, since the
failure of a dam in Kingston, Tennessee on 2008 released coal ash
sludge that destroyed several homes and polluted local rivers.
• As of 2016, coal ash sites are now regulated under RCRA.

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Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) (1 of 8)
In the U.S., the federal government has become the
principal participant in the cleanup of hazardous-waste
sites.
The Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) was
enacted in 1980.
This program deals with financing the cleanup of large,
uncontrolled hazardous-waste sites and has become
known as Superfund.

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Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) (2 of 8)
CERCLA had several key objectives:
• To set priorities for cleaning up the worst existing sites
• To make those who created the hazardous waste site (potentially
responsible parties) pay for cleanup when possible
• To set up a $1.6 billion Hazardous Waste Trust Fund (Superfund) to
support the identification and cleanup of abandoned hazardous-
waste sites
• To advance scientific and technological capabilities in hazardous
waste management, treatment, and disposal

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Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) (3 of 8)
Under CERCLA, over 44,000 sites were evaluated, and
about 11,000 were considered serious enough to warrant
further investigation.
• The list of these sites became known as the National Priorities
List.
• The list is still active and the number of sites fluctuates as new sites
are added and old sites are deleted as they are cleaned up.

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Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) (4 of 8)
Many companies found it cost-effective to hire lawyers to
fight their inclusion in cleanup efforts.
About 1100 sites have been cleaned up.
• Most of the remaining sites are in the process of being cleaned up or
are under study about the best way to proceed.
• By 2016, there were about 1,300 sites on the National Priorities List
and 50 more were being considered for inclusion.
$27 billion in total expenditures

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Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) (5 of 8)
The fact that any party could be held responsible for entire
site cleanup caused problems.
This resulted in two pieces of legislation that provided
exemptions to two kinds of parties:
• The Superfund Amendments and Reauthorization Act (SARA)
• The Small Business Liability Relief and Brownfields Revitalization Act
(SBLRBRA)

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Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) (6 of 8)
The Superfund Amendments and Reauthorization Act
(SARA) included several items but one specific provision:
• If, prior to the purchase of commercial real estate, a person or entity
conducted “all appropriate inquiry” using “good and customary
practices” they would not be held responsible for the cleanup of any
contamination on the property.
• This was known as the “innocent landowner defense (ILD).”

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Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) (7 of 8)
Because of the provisions of CERCLA, many previously
abandoned industrial sites were left vacant.
• Developers were not willing to accept the liability they would accept
if they purchased the land for redevelopment.
• These abandoned sites became known as brownfields.

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Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) (8 of 8)
The passage of SBLRBRA in 2002 included new language
that protected purchasers from liability under CERCLA.
• Purchasers of commercial real estate must perform an ASTM Phase 1
Environmental Site Assessment (E-1527) prior to purchasing the land.
• The act also provided funding to conduct site assessment and
planning for redevelopment.
• This act has allowed many remediated Superfund sites to be returned to
a useful function rather than to sit vacant.

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19.7 Hazardous-Waste
Management Choices
The EPA promotes a pollution prevention hierarchy (P2):
• Reduce the amount of pollution at the source.
• Recycle wastes whenever possible.
• Treat wastes to reduce hazard and / or volume.
• Dispose of wastes on land or incinerate them as last resort.

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Pollution-Prevention Hierarchy

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Reducing the Amount of Waste at
the Source
Pollution prevention (P2) encourages changes that
prevent hazardous wastes from being produced.
Many of the actions are simple and cost little.
• U.S. army phasing out lead bullets.
Waste minimization involves manufacturing changes that
can reduce waste.
• Replace hazardous solvents

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Recycling Wastes
Recycling wastes involves using wastes for another
purpose, thus eliminating them as “waste.”
• Burn waste oils and solvents as fuel.
• Incorporate ash or other solid wastes into concrete or other building
materials.

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Treating Wastes
Wastes can be treated in a way that their amount is reduced
or their hazardous nature is modified.
• Neutralization
• Biodegradation
• Air stripping
• Carbon absorption
• Precipitation

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Disposal Methods (1 of 2)
Recycling and treatment activities reduce the amount of
hazardous waste that needs to be disposed of by about 24
percent.
The remaining wastes are typically incinerated or disposed
of on land.
• Incineration (thermal treatment) burns wastes at high temperatures. A
well-designed, well-run incinerator can destroy 99.9999% of
hazardous materials.
• High costs and concerns about emissions have kept incineration from
becoming a major method in North America.

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Disposal Methods (2 of 2)
Land disposal is the primary method used in North
America, because abundant land is available and it is
less expensive than incineration.
• Deep-well injection
• Discharge of treated or untreated liquids into water sources
• Placement of liquid wastes into surface holding areas
• Storage of solid wastes in hazardous waste landfills

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19.8 Toxic Chemical Releases (1 of 2)
The Emergency Planning and Community Right-to-
Know Act (EPCRA) was passed in 1986.
• Any industrial plant that released at least 23,000 kg of toxic
pollutants into the environment was required to file a report.
• These were primarily manufacturing industries.
• The information collected allowed EPA to target specific industries
for enforcement action.

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19.8 Toxic Chemical Releases (2 of 2)
About 400 million kilograms of toxic chemicals were
reported released into the environment by industry in 2015.
• Primary industries involved are mining, power generation, chemical,
and metal manufacturing.

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Sources of Toxic Releases
Source: Data from the U.S Environmental Protection Agency, 2015 Toxic
Release Inventory Report.

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19.9 International Trade
in Hazardous Wastes (1 of 2)
As hazardous waste regulations in industrialized countries
have increased the cost of disposal, export of hazardous
wastes to developing countries became economically
advantageous.
• However, often the receiving countries lacked the administrative and
technological resources to safely dispose of or recycle the waste and
workers used unsafe methods that resulted in their exposure to toxins.

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19.9 International Trade
in Hazardous Wastes (2 of 2)
Objectives of the Basel Convention (taking effect in
1992) are to minimize generation of hazardous wastes
and control and reduce transboundary movements to
protect human health and the environment.
• Although most countries have approved the convention, there are
still individuals or companies that are willing to ignore the rules.

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19.10 Nuclear Waste Disposal (1 of 2)
Radioactive wastes are hazardous and toxic by the
definition of the RCRA but are regulated in a different
manner than other hazardous materials.
The U.S. Nuclear Regulatory Commission (NRC) and the
Department of Energy (DOE) have responsibility for dealing
with nuclear waste.

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19.10 Nuclear Waste Disposal
(2 of 2)
The NRC is primarily responsible for managing spent fuel
from nuclear power plants, waste associated with the
decommissioning of nuclear power plants, and low-level
waste from a variety of sources.
The DOE has major responsibility for the waste associated
with cleaning up contaminated sites resulting from research
and weapons development.

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Sources of Nuclear Waste
The nuclear fuel cycle involves mining uranium,
processing it, using it as fuel for nuclear reactors, and
reprocessing or disposing of spent fuel.
• Each of these steps in the process results in some nuclear waste.
The legacy of past nuclear research and weapons
development resulted in a great deal of waste and
contamination

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19.10 Nuclear Waste Disposal
The DOE has become steward of a large number of sites
that are contaminated with hazardous chemicals and
radioactive materials.
• There were thousands of contaminated sites containing hundreds of
underground storage tanks, millions of 55 gallon drums of waste, and
thousands of sites with contaminated soils.
• Several major sites have been cleaned up.
• Each year there are fewer sites, and those remaining are smaller.

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Contamination from Nuclear Research
and Weapons Production (1 of 2)
In the United States, nuclear research and development
was initially related to the development of weapons for use
during World War II.
• Many of the research and production facilities dealt with hazardous
chemicals and minor radioactive wastes by burying them, pumping
them into the ground, storing them in ponds, or releasing them into
rivers.

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Contamination from Nuclear Research
and Weapons Production (2 of 2)
Ultimately the Department of Energy (DOE) assumed
responsibility the stewardship of the facilities used for
both nuclear energy research and weapons production.
• A large number of these sites are contaminated with both
hazardous chemicals and radioactive materials.
• Over 500 sites were evaluated to determine if cleanup activities
were required.
• Over 100 sites required some level of cleanup.

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Contaminated Nuclear Sites
Remaining
Source: Data from the U.S Department of Energy.

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Disposal Methods
There are four general categories of nuclear wastes:
• Transuranic wastes are highly radioactive waste that contain large
numbers of atoms that are larger than uranium with half-lives greater
than 20 years.
• Uranium mining and milling wastes have low levels of radioactivity
but are above background levels.
• High-level radioactive wastes are spent fuel rods and highly
radioactive materials from the reprocessing of fuel rods.
• Low-level radioactive wastes have low levels of radioactivity and
are not classified into one of the other categories.

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Transuranic Waste Disposal
Transuranic waste from former nuclear weapons sites is
transported to the Waste Isolation Pilot Plant (WIPP) near
Carlsbad, NM.
• This facility began accepting waste in March, 1999.

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Waste Isolation Pilot Plant
Source: U.S Department of Energy.

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Uranium Mining and Milling Waste
Waste management activities of mining and milling waste
include:
• Building fences.
• Putting up warning signs.
• Establishing land use restrictions.
• Covering the wastes with a thick layer of soil and rock to prevent
erosion, windblown particles, and groundwater contamination.

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Uranium Mine Tailings
Source: U.S. Environmental Protection Agency

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High-Level Radioactive Waste
Disposal (1 of 2)
Disposal of high-level radioactive waste is a major
problem for the nuclear power industry.
• In the U.S., about 76,000 metric tons (84,000 U.S. tons) of highly
radioactive spent fuel rods are stored in special storage ponds at
nuclear reactor sites.
• There is no permanent storage facility, and many plants are running
out of temporary storage.
• Most experts feel the best solution is to bury waste in a stable
geologic formation.

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High-Level Radioactive Waste
Disposal (2 of 2)
Storage of Spent Fuel Rods Aboveground Storage of
Spent Fuel Rods
Source: U.S. Department of Energy

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Low-Level Radioactive Waste
Disposal
Currently, the U.S. produces about 57,000 cubic meters of
low-level radioactive waste annually.
• It is presently buried in disposal sites in South Carolina,
Washington, and Utah.
• 1986 was the deadline for each state providing its own storage
sites.
• Later states formed regional compacts where one state provided a
disposal site.
• Today many states do not have a permanent disposal site for low-
level radioactive waste.

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Low-Level Radioactive Waste Sites
Source: Nuclear Regulatory Commission.

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Summary (1 of 3)
Industrialized countries of Europe and North America
began major regulation of hazardous materials only
during the past 40 years.
Many developing countries exercise little or no control
over such substances.
There is no agreement as to what constitutes a
hazardous waste.
Things that burn, explode, corrode, and cause oxidation
are typically included along with gases, radioactive
materials, and poisons.

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Summary (2 of 3)
There is a difference between acute toxicity and chronic
toxicity.
Toxins may also be persistent or nonpersistent.
RCRA established a cradle-to-grave system of dealing
with hazardous wastes.
CERCLA established programs for cleaning up
hazardous waste sites.
The primary sources of toxic releases are mining
operations and electric power plants.

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Summary (3 of 3)
The current strategy of the EPA is to limit the production
of hazardous waste by reducing the waste at the source,
recycling material so that it does not become waste,
treating waste to reduce its hazard or volume, and as a
last resort, disposing of the waste.
High-level nuclear waste is currently stored on the site of
nuclear power plants.
Low-level nuclear waste is stored in secure landfills at
four sites.