Environmental Encyclopedia

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Environmental Encyclopedia 3

Hawaiian Islands

division between the rich and the poor in the world is widen-

ing, and that many resources and ecosystems on earth are

being stressed, though how close to the breaking point no

one really knows. Also, nation-states are arbitrary divisions,

and perhaps—in a corollary to the space-ship metaphor—

the ultimate life-boat is the earth and all the inhabitants

must exist in it together.

Hardin retired as a professor emeritus of human ecol-

ogy, a rare title that reflects his attempts to fold the human

species

into the evolutionary ecology perspective developed

in biology. Ultimately what he tried to get across was what

he called an ecolate view: ecolacy asks the question “and then

what?” The basic insight of the ecolate citizen is that the

world is a complex of systems so intricately interconnected

that we can seldom be very confident that a proposed inter-

vention in this system of systems will produce the conse-

quences we want.” Hardin’s views are rich and varied—the

themes presented here are only two of many—but he still

summarizes the human condition by what he labels “the

ecolate predicament": that all human interventions are

doomed to failure if a population exceeds its carrying capac-

ity, whether of a region or of the world. Doing so “will bring

everyone down to a level of poverty.”

[Gerald L. Young Ph.D.]

ESOURCES

OOKS

Hardin, G. “Living on a Lifeboat.” BioScience 24, no. 10, (October 1974):

561–568.

———. Living Within Limits: Ecology, Economics, and Population Taboos.

New York: Oxford University Press, 1993.

———. The Ostrich Factor: Our Population Myopia. New York: Oxford

University Press, 1999.

ERIODICALS

Bajema, C. J. “Garrett James Hardin: Ecologist, Educator, Ethicist, and

Environmentalist.” Population and Environment 12, no. 3, (Spring 1991):

193–212.

———. “The Tragedy of the Commons.” Science 162, (13 December 1968):

1243–1248.

Hawaiian Islands

The Hawaiian Islands are made up of a chain of ancient

volcanic islands that have formed at irregular intervals over

the last ten million years. There are over 100 islands in the

chain, eight of which are considered major. Of the eight

major islands, Kauai is the oldest, and the island of Hawaii

is the youngest, having formed within the past million years.

This vast discrepancy in age has contributed to the tremen-

dous

biodiversity

that has evolved there. The other factor

697

responsible for Hawaii’s great

species

diversity is the island

chain’s remoteness. The nearest continent is 2,400 mi (3,862

km) away, thus limiting the total colonization that could,

or has, taken place. The niches available to these colonizing

species are very diverse due to geophysical events. For exam-

ple, on the island of Kauai, the average annual rainfall on

the windward side of Mount Waialeale is 460 in (1,169 cm),

whereas on its leeward side, it is only 19 in (48 cm). The

temperature on the islands ranges from 75–90°F (24–32°C)

for 300 days each year. The lowest temperature ever recorded

in Hawaii was 54°F (12°C). Thus with its tropical

climate

and unique biotic communities, it is easy to understand why

Hawaii has been considered a paradise. But now this paradise

is threatened by serious environmental problems caused by

humans.

The impact of humans has been felt in the Hawaiian

Islands since their first arrival, but perhaps never more so

than today. In the last quarter century tourism has replaced

sugar cane and pineapple as the islands’ main revenue source.

Over six million tourists visit Hawaii each year spend $11

million a day. With tourism comes development that often

destroys natural habitats and strains existing

natural re-

sources

. Hawaii has more than 60

golf courses

, with plans

to develop at least 100 more. This would destroy thousands

of acres of natural vegetation, require the use of millions of

gallons of freshwater for

irrigation

, and necessitate the use

of tons of chemical fertilizers and pesticides in their mainte-

nance. The increased number of tourists, many of whom

visit the islands to enjoy its natural beauty, are often destroy-

ing the very thing they are there to see. Along the shore of

Hanauma Bay, just south of Honolulu, over 90% of the

coral reef

is dead, primarily because people have trampled

it in their desire to see and experience this unique piece of

nature

Much of Hawaii’s

fauna

and

flora

are unique. Over

10,000 species are native to the Hawaiian Islands, having

evolved and filled specialized niches there through the pro-

cess of adaptive radiation from the relatively few original

colonizing species. Examples are found in virtually every

group of plants and animals in Hawaii. The avian adaptive

radiation in the Hawaiian Islands surpasses even the best-

known example, Darwin’s finches of the Galapagos Islands.

From as few as 15 colonizing species evolved 90 native

species of birds in the Hawaiian archipelago. Included in

this number are the Hawaiian honeycreepers of the family

Drepanididae. This endemic family of birds arose from a

single ancestral species, which gave rise to 23 species, includ-

ing 24 subspecies, of honeycreepers spread throughout the

main islands.

Niche

availability and reproductive isolation

contributed greatly to the spectacular diversity of forms that

evolved. These birds developed adaptations such as finch-

like bills for crushing seeds, parrot-like bills for foraging on

Environmental Encyclopedia 3

Hawaiian Islands

larvae in wood, long decurved bills for taking nectar and

insects from specialized flowers, and small forcep-like bills

for capturing insects.

Introductions of vast numbers of alien species is taking

its toll on native Hawaiian species, a process that began

when the first humans settled the islands over 1,500 years

ago. Many native species of birds had experienced drastic

population declines by the time Europeans first encountered

the islands over 200 years ago. Since then at least 23 species

of Hawaii’s native birdlife have become extinct, and currently

over 30 additional avian species are threatened with

extinc-

tion

. Through the process of primary ecological

succession

one new species became established in the Hawaiian Islands

every 70,000 years. Introductions of alien species are taking

place a million times faster, and are thus eliminating native

species at an unprecedented rate. Recent estimates indicate

that there are over 8,000

introduced species

of plants and

animals throughout the Hawaiian Island chain. The original

Polynesian settlers brought with them pigs, dogs, chickens,

and rats, along with a variety of plants they had cultivated

for fiber, food, and medicine. With the Europeans came

cattle, horses, sheep, cats, and additional rodents. The mon-

goose was introduced purposefully to control the rat popula-

tions; however, they presented more of a threat to ground-

nesting birds. The introduction of rabbits caused the loss of

vast quantities of vegetation and ultimately the extinction

of three bird species on Laysan Island. Over 150 species of

birds, including escaped cage birds, have been introduced

to the islands. However, most of these have not established

breeding populations.

Although Hawaii represents only 0.2% of the United

States’s land base, almost 75% of the total extinctions of

birds and plants of the nation have occurred in this state.

Hawaii’s endemic flora are disappearing rapidly. Introduced

mammalian browsers are decimating the native plantlife,

which never needed to evolve defense mechanisms against

such predators, and other introduced animals are destroying

populations of native pollinators.

Habitat

destruction and

opportunistic non-native vegetation are also working against

the endemic Hawaiian plant species. Organizations such as

the Hawaii Plant Conservation Center are working to pre-

serve the state’s floral diversity by collecting and propagating

as many of the rare and

endangered species

as possible.

Their greenhouses now contain over 2,000 plants represent-

ing almost two thirds of Hawaii’s native species, and their

goal is to propagate 400 of the state’s most endangered

plants.

Introduced plant and animal species and their assault

on native species are by no means the only environmental

problems facing the Hawaiian Islands. Because Hawaii’s

population is growing at a higher rate than the national

average, and in part due to its isolation, it is facing many

698

environmental problems on a grander scale and at a more

rapid rate than its sister states on the mainland. Energy is

one of the primary problems. Much of Hawaii’s electricity

is produced by burning imported oil, which is extremely

expensive. Because of limited reserve capabilities with regard

to electrical generation, Hawaii faces the potential for

blackouts.

Planners have been, over the past several decades, look-

ing at the feasibility of tapping into Hawaii’s seemingly vast

geothermal energy

resources. Hawaii has the most active

volcano

in the world, Kilauea, whose underground network

of geothermal reserves is the largest in the state. The pro-

posed Hawaii Geothermal Deep Water Cable project would

supply the energy for a 500-megawatt power plant, the elec-

trical power of which would be transmitted from the island

of Hawaii to Oahu by three undersea cables. This would,

of, course, be of economic and environmental benefit by

reducing dependence on oil reserves. Opponents of this geo-

thermal power plant point to several problems. They are

concerned with the potential for the release of toxic sub-

stances, such as

hydrogen

sulfide,

lead

mercury

, and chro-

mium, into the

environment

from well-heads. They also

have voiced negative opinions concerning construction of a

geothermal plant so near the lava flows and fissures of

Hawaii’s two active volcanoes. An alternately proposed site

would have the facility located in Hawaii’s last major inhold-

ing of lowland

tropical rain forest

. To avoid economic

disaster from escalating prices for imported oil and the prob-

lem of frequent blackouts, Hawaii must reach some compro-

mise on geothermal energy and/or research the potential for

getting its electricity from one or more of wind, wave, or

solar energy

Hawaii is also faced with environmental problems of

another sort–natural disasters. Volcanoes not only provide

the potential for geothermal energy, they also have the poten-

tial for massive destruction. Over the past 200 years, Hawaii’s

two active volcanoes, Kilauea and Mauna Loa, have covered

nearly 200,000 acres (81,000 ha) of land with lava, and

geologists expect them to remain active for centuries to come.

Severe hurricanes and tidal waves also hold the potential for

vast destruction, not only of human property and lives, but

of natural areas and the

wildlife

it holds. Many of the

endemic species

of Hawaii are threatened or endangered,

and their populations are often so low that a single storm

could wipe out most or all of its numbers.

There are efforts to reverse the environmental destruc-

tion in the Hawaiian Islands. Several organizations com-

prised of native Hawaiians are working to stem the destruc-

tion and loss of the

wilderness

paradise discovered by their

ancestors.

[Eugene C. Beckham]

Environmental Encyclopedia 3

Denis Allen Hayes

ESOURCES

OOKS

Pratt, D., P. Brunner, and D. Berret. The Birds of Hawaii and the Tropical

Pacific. Princeton, NJ: Princeton University Press, 1987.

Scott, J., and J. Sincock. “Hawaiian Birds.” Audubon Wildlife Report 1985.

New York: National Audubon Society, 1985.

Shallenberger, R., ed. Hawaii’s Birds. 3rd ed. Honolulu: Hawaii Audubon

Society, 1981.

Stewart, F., ed. A World Between Waves: Writings on Hawaii’s Rich Natural

History. Washington, DC: Island Press, 1992.

ERIODICALS

White, D. “Plants in a Precarious State.” National Wildlife 31 (May 1993):

30–35.

Denis Allen Hayes (1944 – )

American environmental activist and Earth Day organizer

As executive director of the first

Earth Day

in April 1970,

Hayes helped launch the modern movement of

environ-

mentalism

, and has promoted the use of

solar energy

and

other renewable resources. A native of Camas, Washington,

Hayes acquired his appreciation of

nature

exploring and

enjoying the mountains, lakes, and beaches of the Pacific

Northwest. At age 19, he dropped out of Clark College

in Vancouver, Washington, and spent the next three years

traveling the world. He installed church pews in Honolulu,

taught swimming and modeled in Tokyo, and hitchhiked

through Africa.

After returning to the United States, Hayes enrolled

at Stanford as a history major, was elected student body

president, and became active in the anti-Viet Nam War

movement, occupying laboratories that researched military

projects. After graduating from Stanford, he went to Harvard

Law School, but dropped out in 1970 to help organize the

first Earth Day. During the Carter administration, Hayes

headed the federal Solar Energy Research Institute. He left

after the agency’s $120 million budget was cut by the Reagan

administration. From 1983 to 1992, after completing his law

degree at Stanford, he served there as an adjunct professor of

engineering.

In 1990, as the international chairman of Earth Day

on its twentieth anniversary, Hayes helped to organize par-

ticipation by over 200 million people in 141 countries. This

event generated extraordinary publicity for and concern

about global environmental problems. In 1992, Hayes was

named president of the Seattle-based Bullitt Foundation,

which works to protect the

environment

of the Pacific

Northwest and to help disadvantaged children. He also

serves as chairman of the board of

Green Seal

, a group that

endorses consumer products meeting strict environmental

standards and co-chairs the group promoting the “Valdez

Principles” of corporate responsibility.

699

Denis Hayes. (Corbis-Bettmann. Reproduced by per-

mission.)

Hayes has received awards and honors from many

groups, including the

Humane Society of the United

States

, the Interfaith Center for Corporate responsibility,

the

National Wildlife Federation

, and the

Sierra Club

.In

1990, Life magazine named him one of the 18 Americans

most likely to have an impact on the twenty-first century.

Hayes has written over 100 papers and articles, and

his book on solar energy, Rays of Hope: The Transition to a

Post-Petroleum World, has been published in six languages.

He has long advocated increased development of solar and

other

renewable energy

sources, which he believes could

provide most of the nation’s energy supply within a few years.

In 1990, Hayes wrote that “Time is running out. We

have at most ten years to embark on some undertakings if

we are to avoid crossing some dire environmental thresholds.

Individually, each of us can do only a little. Together, we

can save the world.”

[Lewis G. Regenstein]

ESOURCES

OOKS

Hayes, D. Rays of Hope: The Transition to a Post-Petroleum World. New

York: Norton, 1977.

Environmental Encyclopedia 3

Hazard ranking system

ERIODICALS

Hayes, D. “Earth Day 1990: Threshold of the Green Decade.” Natural

History 99 (April 1990): 55–60.

———. “The Green Decade.” Amicus Journal 12 (Spring 1990): 10–21.

Reed, S. “Twenty Years After He Mobilized Earth Day, Denis Hayes Is

Still Racing to Save Our Planet.” People Weekly, April 2, 1990, 96–99.

Ridenour, J. M., et al. “Global Prescription: Leading Conservationists Look

to the Future and Speak Their Minds.” National Parks 64 (March–April

1990): 16–18.

Hazard ranking system

The Hazard ranking system (HRS) is a numerical scoring

procedure that the federal

Environmental Protection

Agency

(EPA) uses to place and prioritize waste sites on

the

National Priorities List

. Only these priority sites can

be cleaned up through the Superfund Trust Fund program.

The HRS score is based on an evaluation of threats

related to the release or potential release of hazardous sub-

stances. The HRS assessment of a site ranks public health

factors such as threats to drinking water, the food chain,

and populations exposed through occupational and ambient

environments. Also evaluated are environmental threats like

the effect of substances on

air quality

, resources, and sensi-

tive ecosystems.

Federal investigators score a site by evaluating four

pathways that could be affected by hazardous releases. The

pathways are ground water

migration

, surface water migra-

tion, air migration, and

soil

exposure.

The pathway scores are combined using a root-mean-

square equation. This calculation produces the overall score

for a site. A high HRS score does not guarantee immediate

action because clean-up work may be going on at other sites.

The decision to take action on a site is based on additional

research that includes a remedial investigation of what cor-

rective action is needed.

[Liz Swain]

Hazardous materials, solidification of

see

Solidification of hazardous materials

Hazardous chemicals

see

Hazardous material; Hazardous

waste

Hazardous material

Any agent that presents a risk to life-forms or the

environ-

ment

can be considered a hazardous material. This is a

700

very broad term which encompasses pure compounds and

mixtures, raw materials, and other naturally occurring sub-

stances, as well as industrial products and wastes. Depending

on the nature and the length of exposure, virtually all sub-

stances can have toxic effects, ranging from headaches and

dizziness to

cancer

. The challenge facing any legislation is

not only to devise regulations for the safe handling of hazard-

ous materials but also to define the term itself.

The legislation that offers the most detailed and com-

prehensive definition of hazardous materials is the

Resource

Conservation and Recovery Act

(RCRA), enacted in 1976.

RCRA classifies a waste mixture or compound as hazardous

if it fails what is called a characteristic test or appears on one

of a few lists. The lists of hazardous wastes include those

from specific and nonspecific sources and those which are

acutely hazardous and generally hazardous. There are four

characteristic tests: ignitability, reactivity, corrosivity, and

extraction-procedure toxicity.

A waste fails the ignitable test if it is a liquid with flash

point below 140°F (60°C); or a solid that, under standard

temperature and pressure, causes fire through friction, ab-

sorbing moisture, or spontaneous changes and burns vigor-

ously and persistently; or a compressed gas defined by the

Department of

Transportation

(DOT) as an oxidizer or as

being ignitable. Spent solvents, paint removers, epoxy resins,

and waste inks are often classified as hazardous under this

definition.

A waste fails the corrosivity test if it is aqueous and

has a

of either 2 or less or 12.5 or more, or if it is a

liquid that corrodes steel at a rate equal to or more than

0.25 in (6.35 mm) per year. Examples of corrosive wastes

include various acids and bases such as nitric

acid

, ammo-

nium hydroxide, perchloric acid, sulfuric acid, and sodium

hydroxide, though a waste will not be classified as hazardous

in this test if these acids and bases are neutralized or present

at low levels.

Reactivity is related to one of the following criteria:

If the material is unstable, with the potential for violent

reactions with water, or generates toxic fumes; if it has

cyanide and sulfide content; if it can be easily detonated; or

is defined by DOT as a Class A or B explosive. Compounds

commonly causing wastes to fall into this category are chro-

mic acid, hypochlorites, picric acid, nitroglycerin, dinitro-

phenol, and organic peroxides.

Extraction-Procedure toxicity is determined through

the extraction of

solid waste

, in a procedure referred to as

the Toxicity Characteristic Leaching Procedure (TCLP). Liq-

uid waste can also fail this test, although a liquid containing

less than 0.5% solids after

filtration

does not need to undergo

it. Such a liquid can be directly analyzed for contaminants.

In the TCLP, solids are extracted in a mildly acidic medium

(pH 5.0) for 18 hours using a tumbling apparatus, and the

Environmental Encyclopedia 3

Hazardous Materials Transportation Act (1975)

resulting liquid extract is then analyzed for contaminants.

The waste is deemed to be hazardous if the level of a contam-

inant detected in this extraction procedure exceeds a given

level. If liquid extracts contain

arsenic

at a concentration

greater than 5.0 mg/l, for example, the waste is classified

as hazardous. Different methods are recommended by the

Environmental Protection Agency

(EPA) for measuring

the contaminants in each class.

The Resource Conservation and Recovery Act (1976)

and the Hazardous and Solid Waste Amendments added

to it in 1984 were intended to protect

groundwater

, surface

water, and land from improper management of solid wastes.

The act and the amendments defined the responsibilities of

industries and others who generate and transport

hazardous

waste

. They also set standards for land disposal facilities

and underground storage tanks, as well as standards for

proper management of hazardous materials from “cradle to

grave.”

The Toxic Substances Control Act (1976) is another

important piece of legislation concerning hazardous materi-

als. It was intended to regulate the introduction and use

of new, potentially hazardous substances. The bill requires

industry to test extensively

chemicals

that may be harmful,

and it requires industries to provide the EPA with informa-

tion about the production, use, and health effects of any

new substances or mixtures before they are manufactured.

The Comprehensive Environmental Response, Com-

pensation and Liabilities Act (CERCLA) (1980) and the

Superfund Amendments and Reauthorization Act (SARA)

(1986) set policy for situations in which hazardous materials

have been mismanaged in the past. These legislations have

established a system for ranking sites that need

remediation

called the

Hazard Ranking System

, as well as a procedure

for raising funds to support these efforts. The bills also

impose schedules for site investigations, feasibility studies,

and remedial action.

The definition of hazardous materials remains a diffi-

cult and complex issue. There are changes in public percep-

tions about certain materials, such as

asbestos

lead

, and

there are scientific contributions which result in the addition

or deletion of various chemicals or compounds from lists of

hazardous materials. The definition is therefore dynamic, but

changes are made within a regulatory framework designed to

protect both life and the environment.

[Gregory D. Boardman]

ESOURCES

OOKS

Corbitt, R. A. Standard Handbook of Environmental Engineering. New York:

McGraw-Hill, 1990.

701

Freeman, H. M. Standard Handbook of Hazardous Waste Treatment and

Disposal. New York: McGraw-Hill, 1989.

Martin, E. J., and J. H. Johnson. Hazardous Waste Management Engineering.

New York: Van Nostrand Reinhold, 1987.

Sax, N. I. Dangerous Properties of Industrial Materials. 6th ed. New York:

Van Nostrand Reinhold, 1984.

Wagner, T. P. Hazardous Waste Identification and Classification Manual.

New York: Van Nostrand Reinhold, 1990.

Wentz, C. A. Hazardous Waste Management. New York: McGraw-Hill,

1989.

Hazardous materials, storage and

transport

see

Storage and transport of hazardous

material

Hazardous Materials Transportation

Act (1975)

The Hazardous Materials

Transportation

Act, enacted in

1975 as part of a law dealing with transportation safety,

strengthened the 1970 Hazardous Materials Transportation

Control Act. The impetus for this act was increased illegal, or

midnight, dumping; increasing spills; and poor enforcement.

Illegal dumping increased in the 1970s as many landfills

began to refuse to take

hazardous waste

, thus dramatically

increasing the costs of disposal. The illegal dumping took

place in vacant lots, along highways, or actually on the high-

ways. In the congressional debate on the act, the U.S. De-

partment of Transportation (DOT), which administers the

law, estimated that 75% of all hazardous waste shipments

violated the existing regulations. This poor enforcement was

due to a lack of inspection personnel, fragmented jurisdiction

and lack of coordination among the Coast Guard, the Fed-

eral Aviation Administration, the Federal Highway Admin-

istration, and the Federal Railroad Administration.

The law establishes minimum standards of regulation

for the transport of hazardous materials by air, ship, rail,

and motor vehicle. The DOT regulates the packing, labeling,

handling, vehicle routing, and manufacture of packing and

transport containers for hazardous materials transportation.

The hazardous materials and wastes covered by the law,

based on DOT regulations, are those on the

Resource Con-

servation and Recovery Act

(RCRA) list and certain sub-

stances designated by the

Environmental Protection

Agency

under the authority of Superfund. All hazardous

waste transporters must register as such with the proper state

and federal agencies; they must use the RCRA uniform

manifest system to track the pick-up and delivery of all

shipments; they must only deliver to permitted hazardous

waste facilities; they must notify the proper agencies of any

accidents; they must clean up any discharges that occur

Environmental Encyclopedia 3

Hazardous Substances Act (1960)

during the transportation process. The law also provides a

significant role for the states, though there are provisions in

the act to prevent overly strict state and local regulations of

hazardous waste transport. The Hazardous Materials Trans-

portation Act includes numerous information requirements,

also designed to increase public safety. Each vehicle carrying

hazardous materials must display a sign identifying the haz-

ard class of the cargo, and emergency response information

has been required since 1990. Each shipment must also be

accompanied by its RCRA hazardous waste manifest.

The manifest system is part of the RCRA “cradle-

to-grave” approach to regulating hazardous materials. The

system is supposed to prevent illegal dumping, since hazard-

ous waste transporters could not accept hazardous waste

without a manifest, and, similarly, hazardous waste treat-

ment and disposal facilities could not accept waste from

transporters without a manifest. Since all hazardous materi-

als could be traced and accounted for through such manifests,

illegal dumping should stop. Nevertheless, it is unclear how

much effect the manifest system has had on illegal dumping

since such dumping is still less costly than proper disposal.

In 1990, the Hazardous Materials Transportation

Uniform Safety Act was passed, the first major amendments

to the 1975 Act. Poor enforcement of the existing law was

the stimulus for action. The law focused on better enforce-

ment by increasing the number of inspectors, increasing the

civil and criminal penalties for violation of the regulations,

and helping states better respond to accidents involving haz-

ardous materials. See also Chemical spills; Comprehensive

Environmental Response, Compensation and Liability Act

(CERLA) (1980); Hazardous waste siting; Solidification

of hazardous material; Storage and transport of hazardous

materials

[Christopher McGrory Klyza]

ESOURCES

OOKS

Dower, R. C. “Hazardous Wastes.” Public Policies for Environmental Protec-

tion, edited by P. R. Portney. Washington, DC: Resources for the Fu-

ture, 1990.

Mazmanian, D., and D. Morell. Beyond Superfailure: America’s Toxics Policy

for the 1990s. Denver: Westview Press, 1992.

ERIODICALS

“Hazardous Materials Law Strengthened.” Congressional Quarterly Almanac

46 (1990): 380–82.

Hazardous Substances Act (1960)

This law was one of Congress’s first forays into consumer

protection, and it helped to pave the way for the explosion

in consumer protection legislation that began in the mid-

702

1960s. The Hazardous Substances Labeling Act was passed

in 1960 (the word “Labeling” was deleted by the 1966

amendments the act). The law authorized the Secretary of

the Department of Health, Education, and Welfare (HEW)

to require warning labels for household substances that were

deemed hazardous. These substances were categorized as:

toxic, corrosive, irritant, strong sensitizer, flammable or com-

bustible, pressure generating, or radioactive. The law does

not cover pesticides (which are regulated by the Federal

Insecticide,

Fungicide

, and Rodenticide Act); food, drugs,

or cosmetics (which are covered by the Federal Food, Drug,

and Cosmetics Act); radioactive materials related to

nuclear

power

; fuels for cooking, heating, or refrigeration; or

to-

bacco

products.

A product is defined to be hazardous if it might lead

to personal injury or substantial illness, especially if there is

a reasonable danger that a child might ingest the substance.

When the HEW Secretary declares a substance to be hazard-

ous, a label is required. The label must include a description

of the chief hazard and first aid instructions, along with

handling and storage instructions. If its chief hazard is flam-

mable, corrosive, or toxic, it must say DANGER on the

label; other hazardous substances require either CAUTION

or WARNING. In addition, all labels must include the

statement “Keep out of the reach of children.”

Major amendments to the act, the Child Protection

Act, were passed in 1966. These amendments, largely in

response to the message on consumer issues by President

Lyndon Johnson, expanded federal control over hazardous

substances. The

Food and Drug Administration

(FDA),

which administered the law, could now ban substances (after

formal hearings) that were deemed too hazardous, even if

they had a warning label, if “the degree or

nature

of the

hazard involved in the presence or use of such substance in

households is such that the objective of the protection the

public health and safety can be adequately served” only by

such a ban. The amendments also extended the scope of the

law to pay greater attention to toys and children’s articles.

This meant the government could require a warning on all

household items, rather than just packaged items.

The Child Protection and Toy Safety Act of 1969 fur-

ther amended the Hazardous Substances Act. Toys could be

declared hazardous if they presented electrical, mechanical,

or thermal dangers. Also, substances that were hazardous to

children, including toys, could be banned automatically. As

the titles of these amendments suggest, the Hazardous Sub-

stances Act became the primary vehicle to protect children

from dangerous substances and toys. Administration of the

act has been shifted to the Consumer Product Safety Com-

mission. If the Commission finds a “substantial risk of injury,”

children’s clothes, furniture, and toys can be pulled from the

market immediately. See also Environmental law; Hazardous

Environmental Encyclopedia 3

Hazardous waste

material; Hazardous Materials Transportation Act; Hazard-

ous waste; Hazardous waste siting; Radioactive waste; Radio-

activity

[Christopher McGrory Klyza]

ESOURCES

ERIODICALS

“Child Protection.” Congressional Quarterly Almanac 22 (1966): 325–7.

“Toy Safety,” Congressional Quarterly Almanac 25 (1969): 248–50.

Hazardous waste

Of the thousands of millions of tons of waste generated in

the United States annually, approximately 60 million tons are

classified as hazardous. Hazardous waste is legally defined by

the

Resource Conservation and Recovery Act

(RCRA) of

1976. The RCRA defines hazardous waste as any waste or

combination of wastes, which because of its quantity, concen-

tration,orphysical,chemical,orinfectiouscharacteristicsmay:

A) cause, or significantly contribute to, an increase in

mortal-

ity

or an increase in serious irreversible or incapacitating ill-

ness; or, B) pose a substantial present or potential hazard to

human health or the

environment

when improperly treated,

stored, transported, disposed of, or otherwise managed.

In the Code of Federal Regulations, the

Environmen-

tal Protection Agency

(EPA) specifies that a

solid waste

is hazardous if it meets any of four conditions: 1) It exhibits

ignitability corrosivity, reactivity, or EP toxicity; 2) has been

listed as a hazardous waste; 3) is a mixture containing a

listed hazardous waste and a nonhazardous waste, unless the

mixture is specifically excluded or no longer exhibits any of

the four characteristics of hazardous waste; 4) is not specifi-

cally excluded from regulation as a hazardous waste.

The EPA established two criteria for selecting the

characteristics given above. The first criterion is that the

characteristic is capable of being defined in terms of physical,

chemical, or other properties. The second criterion is that

the properties defining the characteristic must be measurable

by standardized and available test procedures. For example

under the term ignitability (Hazard code label “I"), any one

of four criteria can be met: 1) A liquid with a flash point

less than 60°F (16°C); 2) If not a liquid, then it is capable

under standard temperature and pressure of causing fire

through friction,

absorption

of moisture, or spontaneous

chemical changes, and when ignited, burns so vigorously

and persistently that it creates a hazard; 3) It may be an

ignitable compressed gas; 4) It is an oxidizer.

Similarly under the characteristics of corrosivity, reac-

tivity, and toxicity, there are specifically defined require-

ments which are spelled out in the Code of Federal Register

(CFR). Further examples are given below:

703

Corrosivity (Hazard code “C") has either of the follow-

ing properties: an aqueous waste with a

equal to or less

than 2.0 or greater than 12.5; or a liquid which will corrode

carbon

steel at a rate greater than 0.25 in (0.64 cm) per year.

Reactivity (Hazard code “R") has at least one of the

following properties: a substance which is normally unstable

and undergoes violent physical and/or chemical change with-

out being detonated; a substance which reacts violently with

water (for example, sodium metal); a substance which forms

a potentially explosive mixture when mixed with water; a

substance which can generate harmful gases, vapors, or fumes

when mixed with water; a cyanide- or sulfide-bearing waste

which can generate harmful gases, vapors, or fumes when

exposed to pH conditions between 2 and 12.5; a waste which,

when subjected to a strong initiating source or when heated

in confinement, will detonate and/or generate an explosive

reaction; a substance which is readily capable of detonation

at standard temperature and pressure.

Toxicity (Hazard code “E") has the properties such that

an aqueous extract contains contamination in excess of that

allowed (e.g.,

arsenic

>5 mg/l; barium 0.100 mg/l;

cadmium

>1 mg/l; chromium >5 mg/l;

lead

>5 mg/l). Additional codes

under toxicity include an “acute hazardous waste” with code

“H": a substance which has been found to be fatal to humans

in low doses or has been found to be fatal in corresponding

human concentrations in laboratory animals. Toxic waste

(hazard code “T") designates wastes which have been found

through laboratory studies to be a

carcinogen

mutagen

,or

teratogen

for humans or other life forms.

Certain wastes are specifically excluded from classifica-

tion as hazardous wastes under RCRA, including domestic

sewage,

irrigation

return flows,

household waste

, and nu-

clear waste. The latter is controlled via other legislation. The

impetus for this effort at legislation and classification comes

from several notable cases such as

Love Canal

, New York;

Bhopal, India

;

Stringfellow Acid Pits

(Glen Avon, Califor-

nia); and

Seveso, Italy

; which have brought media and

public attention to the need for identification and classifica-

tion of dangerous substances, their effects on health and the

environment, and the importance of having knowledge about

the potential risk associated with various wastes.

A notable feature of the legislation is its attempt at

defining terms so that professionals in the field and govern-

ment officials will share the same vocabulary. For example,

the difference between “toxic” and “hazardous” has been

established; the former denotes the capacity of a substance

to produce injury and the latter denotes the probability that

injury will result from the use of (or contact with) a substance.

The RCRA legislation on hazardous waste is targeted

toward larger generators of hazardous waste rather than small

operations. The small generator is one who generates less

than 2,205 lb (1,000 kg) per month; accumulates less than

Environmental Encyclopedia 3

Hazardous waste site remediation

2,205 lb (1,000 kg); produces wastes which contain no more

than 2.2 lb (1 kg) of acutely hazardous waste; has containers

no larger than 5.3 gal (20 l) or contained in liners less than

22 lb (10 kg) of weight of acutely hazardous waste; has no

greater than 220 lb (100 kg) of residue or

soil

contaminated

from a spill, etc. The purpose of this exclusion is to enable

the system of regulations to concentrate on the most egre-

gious and sizeable of the entities that contribute to hazardous

waste and thus provide the public with the maximum protec-

tion within the resources of the regulatory and legal systems.

[Malcolm T. Hepworth]

ESOURCES

OOKS

Dawson, G. W., and B. W. Mercer. Hazardous Waste Management. New

York: Wiley, 1986.

Dominguez, G. S., and K. G. Bartlett. Hazardous Waste Management. Vol.

1, The Law of Toxics and Toxic Substances. Boca Raton: CRC Press, 1986.

U.S. Environmental Protection Agency. Hazardous Waste Management: A

Guide to the Regulations. Washington, DC: U.S. Government Printing

Office, 1980.

Wentz, C. A. Hazardous Waste Management. New York: McGraw-Hill,

1989.

Hazardous waste site remediation

The overall objective in remediating

hazardous waste

sites

is the protection of human health and the

environment

reducing risk. There are three primary approaches which

can be used in site

remediation

to achieve acceptable levels

of risk:

the hazardous waste at a site can be contained to preclude

additional

migration

and exposure

the hazardous constituents can be removed from the site to

make them more amenable to subsequent ex situ treatment,

whether in the form of

detoxification

or destruction

the hazardous waste can be treated in situ (in place) to

destroy or otherwise detoxify the hazardous constituents

Each of these approaches has positive and negative

ramifications. Combinations of the three principal ap-

proaches may be used to address the various problems at a

site. There is a growing menu of technologies available to

implement each of these remedial approaches. Given the

complexity of many of the sites, it is not uncommon to have

treatment trains with a sequential implementation of various

in situ and/or ex situ technologies to remediate a site.

Hazardous waste site remediation usually addresses

soils and

groundwater

. However, it can also include wastes,

surface water,

sediment

, sludges, bedrock, buildings, and

other man-made items. The hazardous constituents may be

organic, inorganic and, occasionally, radioactive. They may

704

be elemental ionic, dissolved, sorbed, liquid, gaseous, vapor-

ous, solid, or any combination of these.

Hazardous waste sites may be identified, evaluated,

and if necessary, remediated by their owners on a voluntary

basis to reduce environmental and health effects or to limit

prospective liability. However, in the United States, there

are two far-reaching federal laws which may mandate entry

into the remediation process: the

Comprehensive Environ-

mental Response, Compensation, and Liability Act

(CERCLA, also called the Superfund law), and the

Re-

source Conservation and Recovery Act

(RCRA). In addi-

tion, many of the states have their own programs concerning

abandoned and uncontrolled sites, and there are other laws

that involve hazardous site remediation, such as the clean-

up of polychlorinated biphenyl (PCB) under the auspices of

the federal Toxic Substances Control Act (TSCA).

Potential sites may be identified by their owners, by

regulatory agencies, or by the public in some cases. Site

evaluation is usually a complicated and lengthy process. In

the federal Superfund program, sites at which there has been

a release of one or more hazardous substances that might

result in a present or potential future threat to human health

and/or the environment are first evaluated by a Preliminary

Assessment/Site Inspection (PA/SI). The data collected at

this stage is evaluated, and a recommendation for further

action may be formulated. The

Hazard Ranking System

(HRS) of the U.S.

Environmental Protection Agency

(EPA) may be employed to score the site with respect to

the potential hazards it may pose and to see if it is worthy

of inclusion on the

National Priorities List

(NPL) of sites

most deserving the attention of resources.

Regardless of the HRS score or NPL status, the EPA

may require the parties responsible for the release (including

the present property owner) to conduct a further assessment,

in the form of the two-phase Remedial Investigation/Feasi-

bility Study (RI/FS). The objective of the RI is to determine

the nature and extent of contamination at and near the site.

The RI data is next considered in a baseline

risk assess-

ment

. The risk assessment evaluates the potential threats to

human health and the environment in the absence of any

remedial action, considering both present and future condi-

tions. Both exposure and toxicity are considered at this stage.

The baseline risk assessment may support a decision

of no action at a site. If remedial actions are warranted, the

second phase of the RI/FS, an engineering Feasibility Study,

is performed to allow for educated selection of an appropriate

remedy. The final alternatives are evaluated on the basis of

nine criteria in the federal Superfund program. The EPA

selects the remedial action it deems to be most appropriate

and describes it and the process which led to its selection

in the

Record of Decision

(ROD). Public comments are

solicited on the proposed clean-up plan before the ROD is

Environmental Encyclopedia 3

Hazardous waste site remediation

issued. There are also other public comment opportunities

during the RI/FS process. Once the ROD is issued, the

project moves to the Remedial Design/Remedial Action

(RD/RA) phase unless there is a decision of no action.

Upon design approval, construction commences. Then, after

construction is complete, long-term operation, maintenance,

and monitoring activities begin.

For Superfund sites, the EPA may allow one or more

of the responsible parties to conduct the RI/FS and RD/

RA under its oversight. If possibly responsible parties are

not willing to participate or are unable to be involved for

technical, legal, or financial reasons, the EPA may choose

to conduct the project with government funding and then

later seek to recover costs in lawsuits against the parties.

Other types of site remediation programs often replicate or

approximate the approaches described above. Some states,

such as Massachusetts, have very definite programs, while

others are less structured.

Containment is one of the available treatment options.

There are several reasons for using containment techniques.

A primary reason is difficulty in excavating the waste or treat-

ing the hazardous constituents in place. This may be caused

by construction and other man-made objects located over and

in the site. Excavation could also result in uncontrollable re-

leases at concentrations potentially detrimental to the sur-

rounding area. At many sites, the low levels of risks posed, in

conjunction with the relative costs of treatment technologies,

may result in the selection of a containment remedy.

One means of site containment is the use of an imper-

meable cap to reduce rainfall

infiltration

and to prevent

exposure of the waste through

erosion

. Another means of

containment is the use of cut-off walls to restrict or direct

the movement of groundwater. In situ solidification can also

be used to limit the mobility of contaminants. Selection

among alternatives is very site specific and reflects such

things as the site

hydrogeology

, the chemical and physical

nature of the contamination, proposed

land use

, and so on.

Of course, the resultant risk must be acceptable.

As with any in situ approach, there is less control and

knowledge of the performance and behavior of the technol-

ogy than is possible with off-site treatment. Since the use

of containment techniques leaves the waste in place, it usually

results in long-term monitoring programs to determine if

the remediation remains effective. If a containment remedy

were to fail, the site could require implementation of another

type of technology.

The ex situ treatment of hazardous waste provides the

most control over the process and permits the most detailed

assessments of its efficacy. Ex situ treatment technologies

offer the biggest selection of options, but include an addi-

tional risk factor during transport. Examples of treatment

options include

incineration

; innovative thermal destruc-

705

tion, such as infrared incineration;

bioremediation

; stabili-

zation/solidification;

soil

washing; chemical extraction;

chemical destruction; and thermal desorption. Another ap-

proach to categorizing the technologies available for hazard-

ous waste site remediation is based upon their respective

levels of demonstration. There are existing technologies,

which are fully demonstrated and in routine commercial use.

Performance and cost information is available. Examples of

existing technologies include

slurry

walls, caps, incineration,

and conventional solidification/stabilization.

The next level of technology is innovative and has

grown rapidly as the number of sites requiring remediation

grew. Innovative technologies are characterized by limited

availability of cost and performance data. More site-specific

testing is required before an innovative technology can be

considered ready for use at a site. Examples of innovative

technologies are vacuum extraction, bioremediation, soil

washing/flushing, chemical extraction, chemical destruction,

and thermal desorption. Vapor extraction and in situ bior-

emediation are expected to be the next innovative technolo-

gies to reach “existing” status as a result of the growing base

of cost and performance information generated by their use

at many hazardous waste sites.

The last category is that of emerging technologies.

These technologies are at a very early stage of development

and therefore require additional laboratory and pilot scale

testing to demonstrate their technical viability. No cost or per-

formance information is available. An example of an emerging

technology is electrokinetic treatment of soils for metals re-

moval.

Groundwater contaminated by hazardous materials is a

widespread concern. Most hazardous waste site remediations

use a pump and treat approach as a first step. Once the

groundwater has been brought to the surface, various treat-

ment alternatives exist, depending upon the constituents

present. In situ air sparging of the groundwater using pipes,

wells

, or curtains is also being developed for removal of

volatile constituents. The vapor is either treated above

ground with technologies for off-gas emissions, or biologi-

cally in the unsaturated or

vadose zone

above the

aquifer

While this approach eliminates the costs and difficulties in

treating the relatively large volumes of water (with relatively

low contaminant concentrations) generated during pump-

and-treat, it does not necessarily speed up remediation.

Contaminated bedrock frequently serves as a source

of groundwater or soil recontamination. Constituents with

densities greater than water enter the bedrock at fractures,

joints or bedding planes. From these locations, the contami-

nation tends to diffuse in all directions. After many years

of accumulation, bedrock contamination may account for

the majority of the contamination at a site. Currently, little

can be done to remediate contaminated bedrock. Specially

Environmental Encyclopedia 3

Hazardous waste siting

designed vapor stripping applications have been proposed

when the constituents of concern are volatile. Efforts are

on-going in developing means to enhance the fractures of

the bedrock and thereby promote removal. In all cases, the

ultimate remediation will be driven by the diffusion of con-

taminants back out of the rock, a very slow process.

The remediation of buildings contaminated with haz-

ardous waste offers several alternatives. Given the cost of dis-

posal of hazardous wastes, the limited disposal space available,

and the volume of demolition debris, it is beneficial to deter-

mine the extent of contamination of construction materials.

This contamination can then be removed through traditional

engineering approaches, such as scraping or sand blasting. It

is then only this reduced volume of material that requires

treatment or disposal as hazardous waste. The remaining

building can be reoccupied or disposed of as nonhazardous

waste. See also Hazardous material; Hazardous waste siting;

Solidification of hazardous materials; Vapor recovery system

[Ann N. Clarke and Jeffrey L. Pintenich]

ESOURCES

OOKS

U.S. Environmental Protection Agency. Office of Emergency and Remedial

Response. Guidance for Conducting Remedial Investigations and Feasibility

Studies Under CERCLA. Washington, DC: U.S. Government Printing Of-

fice, 1988.

U.S. Environmental Protection Agency. Office of Emergency and Remedial

Response. Handbook: Remedial Action at Waste Disposal Sites. Washington,

DC: U.S. Government Printing Office, 1985.

U.S. Environmental Protection Agency. Office of Emergency and Remedial

Response. Guidance on Remedial Actions for Contaminated Groundwater at

Superfund Sites. Washington, DC: U.S. Government Printing Office, 1988.

U.S. Environmental Protection Agency. Office of Environmental Engi-

neering. Guide for Treatment Technologies for Hazardous Waste at Superfund

Sites. Washington, DC: U.S. Government Printing Office, 1989.

U.S. Environmental Protection Agency. Office of Solid Waste and Emer-

gency Response. Innovative Treatment Technologies. Washington, DC: U.S.

Government Printing Office, 1991.

U.S. Environmental Protection Agency. Risk Reduction Engineering Labo-

ratory. Handbook on In Situ Treatment of Hazardous Waste: Contaminated

Soils. Washington, DC: U.S. Government Printing Office, 1990.

U.S. Environmental Protection Agency. Technology Screening Guide for

Treatment of CERCLA Soils and Sludges. Washington, DC: U.S. Govern-

ment Printing Office, 1988.

Hazardous waste siting

Regardless of the specific technologies to be employed, there

are many technical and nontechnical considerations to be

addressed before

hazardous waste

can be treated or dis-

posed of at a given location. The specific nature and relative

importance of these considerations to the successful siting

reflect the chemodynamic behavior (i.e., transport and fate

of the waste and/or treated residuals in the

environment

706

after

emission

) as well as the specifics of the location and

associated, proximate areas. Examples of these considera-

tions are: the nature of the

soil

and hydrogeological features

such as depth to and quality of

groundwater

; quality, use,

and proximity of surface waters; and

ambient air

quality and

meteorological conditions; and nearby critical environmental

areas (

wetlands

, preserves, etc.), if any. Other considera-

tions include surrounding

land use

; proximity of residences

and other potentially sensitive receptors such as schools,

hospitals, parks, etc.; availability of utilities; and the capacity

and quality of the roadway system. It is also critical to develop

and obtain the timely approval of all appropriate local, state,

and federal permits. Associated with these permits is the

required documentation of financial viability as established

by escrowed closure funds, site insurance, etc. Site-specific

standard operating procedures as well as contingency plans

for use in emergencies are also required. Additionally, there

needs to be baseline and ongoing monitoring plans developed

and implemented to determine if there are any releases to

or general degradation of the environment. One should also

anticipate public hearings before permits are granted. Several

states in the United States have specific regulations which

restrict the siting of hazardous

waste management

facil-

ities.

Haze

aerosol

in the

atmosphere

of sufficient concentration

and extent to decrease

visibility

significantly when the rela-

tive humidity is below saturation is known as haze. Haze

may contain dry particles or droplets or a mixture of both,

depending on the precise value of the humidity. In the

use of the word, there is a connotation of some degree of

permanence. For example, a dust storm is not a haze, but

the coarse particles may settle rapidly and leave a haze behind

once the velocity drops.

Human activity is responsible for many hazes. En-

hanced

emission

sulfur dioxide

results in the formation

of aerosols of sulfuric

acid

. In the presence of ammonia,

which is excreted by most higher animals including humans,

such emissions result in aerosols of ammonium sulfate and

bisulfate. Organic hazes are part of

photochemical smog

such as the

smog

often associated with Los Angeles, and

they consist primarily of polyfunctional, highly oxygenated

compounds with at least five

carbon

atoms. Such hazes can

also form if air with an enhanced

nitrogen

oxide content

meets air containing the natural terpenes emitted by vege-

tation.

All hazes, however, are not products of human activity.

Natural hazes can result from forest fires, dust storms, and

the natural processes that convert gaseous contaminants into

particles for subsequent removal by precipitation or deposi-