Environmental Encyclopedia

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Environmental Encyclopedia 3

Water diversion projects

nating a recharging source for the

groundwater

table.

Eventually, structures put in place to prevent flood damage

may exacerbate the problem. Dams, levees, and other diver-

sional devices prevent water from heavy rainfalls from natu-

rally dispersing onto floodplains and wetlands.

Water diversion projects also impact the

atmosphere

Studies of large reservoirs created behind hydroelectric dams

have suggested that decaying vegetation, submerged by

flooding

, may give off quantities of greenhouse gases—such

methane

gas—equivalent to those from other sources of

electricity. Thus, hydroelectric facilities that flood large areas

of land may be significant contributors to global warming.

The

water quality

of many reservoirs also poses a health

hazard due to new forms of bacteria that grow in many of

the rivers that have been diverted by dams.

In addition to giving off

greenhouse gases

, bacteria

present in decaying vegetation can also change

mercury

present in rocks underlying a reservoir, into a water-soluble

form. The mercury accumulates in the bodies of fish and

poses a health hazard to both wildlife and humans who

depend on these fish as a food source. Methylmercury, the

most toxic form of the element, affects the immune system,

alters genetic and

enzyme

systems, and damages the nervous

system. Human exposure to methylmercury is almost entirely

by eating contaminated fish and wildlife.

A rather surprising global impact of water diversion

projects is that the weight of the world’s collective reservoirs

is speeding up the earth’s rate of rotation and is altering

the shape of earth’s magnetic field, according to NASA

geophysicist Dr. Benjamin Fong Chao.

Human impact

Estimates suggest that approximately 40–80 million

people have been physically displaced by dams worldwide.

Millions of people living downstream from dams, particu-

larly those who rely on natural floodplain function and fisher-

ies, have suffered serious damage to their livelihoods, and

the future productivity of their resources has been put at

risk. Many of the displaced are not recognized as such, and

therefore are not resettled or compensated. When compensa-

tion is provided, it is often inadequate. When the physically

displaced are acknowledged, many are not included in reset-

tlement programs. Moreover, those who are resettled seldom

have their livelihoods restored; resettlement programs usually

focus on physical relocation rather than the economic and

social needs of the displaced.

Indigenous and tribal peoples and vulnerable ethnic

minorities have suffered disproportionate levels of displace-

ment and negative impacts on not only their livelihood, but

also their cultural and spiritual existence. Large dams have

had significant adverse effects on cultural heritage through

the loss, submergence, and degradation of plant and animal

remains, burial sites, and archaeological monuments. The

1477

social, economic, and political status of minority groups

often restricts their capacity to assert their interests and

rights in land and

natural resources

, and restricts their

role in decision-making that affects them.

In addition, affected indigenous populations living

near reservoirs, as well as displaced people and downstream

communities, have often faced adverse health conditions

from environmental change and social disruption. Gender

gaps have widened in these communities, and women have

often borne a disproportionate share of the social costs while

reaping few of the benefits.

Policies and initiatives

Opposition to diversion projects and their impact on

the environment began to pick up momentum in the 1970s.

The

National Environmental Policy Act

of 1970 (NEPA)

required thorough study of the environmental impacts of

proposed water projects, and inspired greater public scrutiny

of the effects of major water projects on the environment.

In 1978, President Jimmy Carter announced a new policy

of cutting federal funding to new water projects, and devel-

oped a “hit list” of dams and irrigation projects.

The financial approach to water management evolved

as well. In 1982, the Reclamation Reform Act was signed

into law, changing the acreage requirements for irrigation

water subsidies in an effort to get large corporate farms to

pay a fair market price for their water use. The

Water

Resources

Development Act (WRDA)—legislation that is

reauthorized by Congress every two years to finance U.S.

Army Corps of Engineers’ water projects—contained

amendments in 1986 that required local interests to share

the construction costs of water resource projects built by the

Corps.

Environmentalists charge that the USBR and the

Army Corps have a history of developing water projects for

financial gain regardless of the cost to the environment. At

the heart of the debate is the fundamental difference in the

way natural water sources are viewed—as a fiscal commodity

or as a natural resource. As Marc Reisner, author of the

critically acclaimed Cadillac Desert, states: “In the East, to

‘waste’ water is to consume it needlessly or excessively. In

the West, to waste water is not to consume it—to let it flow

unimpeded and undiverted down rivers. ... To easterners,

‘conservation’ of water usually means protecting rivers from

development; in the West, it means building dams.” Striking

a balance between these two viewpoints to maintain both

our riparian ecosystem and our Western communities and

businesses, is the challenge facing American government,

environmentalists, and other stakeholders.

Because irrigation for farming is a major consumer

use of diverted water, improving growing techniques and

choosing water-friendly crops may be one solution to min-

imizing water need. The agricultural industry can also take

Environmental Encyclopedia 3

Water Environment Federation

steps to meet irrigation needs in a environmentally responsi-

ble manner by ensuring that adequate fish screens are in

place at diversion points and agreeing to lower water delivery

rates at crucial spawning times to maintain river flow for

migratory fish. Finally,

conservation

and restoration of ag-

ricultural wetlands through government plans such as the

Wetlands Reserve Program can help solve long-term flood-

ing problems on farms and restore the habitats of native

species.

The WRDA of 1999 enacted an Army Corps of Engi-

neers initiative known as “Challenge 21” focused on replac-

ing dams and other diversionary techniques for flood control

with non-structural solutions and environmental restoration

programs. Specifically, the initiative calls for less environ-

mentally-invasive programs of preventing flood damage, in-

cluding federally-funded voluntary buyouts of property on

flood plains and restoration of altered flood plain ecosystems.

International agreements and organizations have also

established standards for minimizing the negative impact of

human activities on biodiversity. Legal coalitions include the

World Charter for Nature, the Convention on Biological

Diversity, and Agenda 21; international organizations such

as the

World Bank

, the World Business Council on

Sus-

tainable Development

, and The World Conservation

Union (IUCN), have contributed to the development of

accepted standards. These standards involve conservation of

species and ecosystems, the recovery of degraded ecosystems,

the conservation of ecological functions or processes, secur-

ing of adequate information for decision-making, and the

adherence to high standards for environmental impact as-

sessments.

[Paula Anne Ford-Martin]

ESOURCES

OOKS

Committee on Missouri River Ecosystem Science; Water, Science, and

Technology Board; Division of Earth and Life Studies; National Research

Council. The Missouri River Ecosystem: Exploring the Prospects for Recovery.

Washington DC: National Academy Press; In press, 2002. Prepublication

copy available online at <http://books.nap.edu/books/0309083141/html/

R1.html>

MacDonnell, Lawrence. From Reclamation to Sustainability: Water, Agricul-

ture, and the Environment in the American West. Boulder: University Press

of Colorado, 1999.

McNully, Patrick. Silenced Rivers: The Ecology and Politics of Large Dams.

2nd edition. London: Zed Books, 2001.

Reisner, Marc. Cadillac Desert: The American West and Its Disappearing

Water. 2nd edition. New York: Penguin, 1987.

ERIODICALS

Bricker, Jennie, and David Filippi. “Endangered Species Act Enforcement

and Western Water Law.” Environmental Law 30, no.4 (Fall 2000): 735.

Robbins, Elaine. “Damning Dams.” emagazine.com (The Environmental

Magazine) X, no. 1 (January-February 1999): 16 [cited June 26, 2002].

<http://www.emagazine.com>.

1478

THER

LakeNet. Strategies and Solutions for Managing Water Diversion. May 15,

2002 [cited June 4, 2002]. <http://www.worldlakes.org/Strategies%20an-

d%20Solutions.htm>.

Stein, Jeff, et al. National Wildlife Federation & Taxpayers for Common

Sense. Troubled Waters: Congress, the Corps of Engineers, and Wasteful Water

Projects Washington, DC: NWF/Taxpayers for Common Sense, 2000.

<http://www.nwf.org/greeningcorps/report.html>.

RGANIZATIONS

American Rivers, 1025 Vermont Ave., N.W. Suite 720, Washington, DC

USA 20005 (202) 347-7550, Fax: (202) 347-9240, Email:

amrivers@amrivers.org, <http://www.amrivers.org>

International Rivers Network, 1847 Berkeley Way, Berkeley, CA USA

94703 (510) 848-1155, Fax: (510) 848-1008, Email: info@irn.org, <http://

www.irn.org>

U.S. Bureau of Reclamation, Freedom of Information Act (FOIA) Office,

PO Box 25007, D-7924, Denver, CO USA 80225-0007 (303) 445-2048,

Fax: (303) 445-6575, Toll Free: (800) 822-7646, Email: borfoia@usbr.gov,

<http://www.usbr.gov>

Water Environment Federation

Dedicated to “the preservation and enhancement of

water

quality

worldwide,” the Water Environment Federation

(WEF) is an international professional organization of water

quality experts. WEF is made up of 38,000 water profession-

als, including engineers, biologists, government officials,

treatment plant managers and operators, laboratory techni-

cians, equipment manufacturers and distributors, and edu-

cators.

WEF was founded in 1928 as the Federation of Sew-

age Works Associations and served as the publisher of the

Sewage Works Journal. The organization has also been known

as the

Water Pollution

Control Federation. Its scope has

broadened significantly since its inception, and WEF cur-

rently publishes a variety of materials relating to the water

industry. WEF also sponsors seminars, conferences, and

briefings; offers technical training and education; produces

informational videos for students; and provides input on

environmental legislation and regulations to government

bodies.

The publications issued by WEF cover a multitude of

topics and are geared toward a variety of readers. Technical

publications, including manuals developed by WEF’s Tech-

nical Practice Committee, brief water-quality professionals

on design, operation, and management innovations in the

field. Periodicals and newsletters address such issues as in-

dustry trends, research findings, water analysis topics, job

safety, regulatory and legislative developments, and job

openings in the profession.

WEF’s technical training and educational programs

are geared toward both professionals and students. Audio-

visual training courses and study guides are available on such

topics as

wastewater

treatment, waste stabilization ponds,

Environmental Encyclopedia 3

Water hyacinth

and wastewater facility management. The federation also

distributes health and safety videos developed by municipali-

ties. For students, WEF offers The Water Environment Cur-

riculum, a series of videos and guides outlining water quality

issues geared toward children in fifth through ninth grades.

The Water Environment Curriculum includes lessons on sur-

face water,

groundwater

, wastewater, and

water conser-

vation

. WEF also publishes guides on water quality issues

for the general public.

WEF’s major event is its annual conference, the largest

water quality and

pollution control

exposition in North

America. The conference features technical sessions, expert

speakers, and exhibits run by companies in the water quality

industry. The federation also holds specialty conferences on

such topics as toxicity, landfills, and surface water quality.

Two other noteworthy briefings are WEF’s Pacific Rim

Conference and the Washington Briefing. The Pacific Rim

Conference gathers representatives from Pacific Rim coun-

tries to discuss environmental problems in that area. The

Washington Briefing convenes government officials and

water quality experts to discuss current issues affecting the

industry.

In addition to its publications, educational tools, and

conferences, WEF sponsors an affiliate, the Water Environ-

ment Research Foundation, which works to develop and

implement water quality innovations. The research founda-

tion’s programs strive to find ways to enhance water quality,

develop broad-based approaches to water quality that en-

compass all aspects of the environment, use new technology,

and promote interaction among individuals involved in the

water quality profession.

WEF is also associated with Water Quality 2000, a

cooperative effort involving a variety of professional and

scientific organizations, industry representatives, environ-

mental groups, academic institutions, and government offi-

cials working on

water quality standards

and goals for

the United States for the twenty-first century.

[Kristin Palm]

ESOURCES

RGANIZATIONS

Water Environment Federation, 601 Wythe Street, Alexandria, VA USA

22314-1994 (703) 684-2452, Toll Free: (800) 666-0206, Email:

csc@wef.org, http://www.wef.org

Water hyacinth

The water hyacinth (Eichhornia crassipes) is an aquatic plant

commonly found in the southern United States, including

Florida, Texas, the Gulf Coast, and California. As an

intro-

duced species

, it has spread rapidly and is now viewed as

1479

Water hyacinth. (Photograph by Ray Coleman. Photo

Researchers Inc. Reproduced by permission.)

a noxious weed. Like other aquatic weeds, water hyacinth

can grow rapidly and clog waterways, damaging underwater

equipment and impairing navigational and recreational facil-

ities. It is also viewed as a weed in many tropical parts of

the world.

Water hyacinths can be either free-floating or rooted,

depending on the depth of the water. The plant height may

vary from a few inches to 3 ft (0.9 m). The leaves, growing

in rosettes, are glossy green and may be up to 8 in (20 cm)

long and 6 in (15 cm) wide. The showy, attractive flowers

may be blue, violet, or white and grow in spikes of several

flowers. The leaf blades are inflated with air sacs, which

enable the plants to float in water. The seeds are very long-

lived. Studies show that seeds that have been buried in mud

for many years remain viable under the right conditions,

leading to reinfestation of lakes long after chemical

treatment.

Weed harvesting methods to control water hyacinth

growth are expensive and not very effective. The weight and

volume of the harvested material usually adds greatly to the

costs of hauling and disposal. Attempts to use the harvested

material as

soil fertilizer

or enhancer have failed because

of the low mineral and nutritive content of the plant’s tissue.

Chemical methods to control water hyacinth usually require

Environmental Encyclopedia 3

Water pollution

careful and repeated applications. Commonly used herbi-

cides include Rodeo and Diquat.

In some situations, aquatic weeds serve beneficial pur-

poses. Aquatic plants can be integral components of

waste-

water

treatment, particularly in warm climates. Wastewater

is routed through lagoons or ponds with dense growths of

water hyacinth. In waters containing excess nutrients (

ni-

trates

and

phosphates

) and turbidity, water hyacinth plants

have been shown to improve

water quality

by taking up the

excess nutrients into the plant and by settling the suspended

solids which cause turbidity. They also add oxygen to the

water through

photosynthesis

. Oxygen is an essential re-

quirement for the

decomposition

of wastewater, and oxygen

deficiency is a common problem in waste treatment systems.

Water hyacinth has been used successfully in California and

Florida, and more states are exploring the possibility of using

water hyacinth in waste treatment systems.

[Usha Vedagiri]

ESOURCES

OOKS

Hammer, Donald A. Constructed Wetlands for Waste Treatment. Chelsea,

MI: Lewis Publishers, Inc., 1989.

Schmidt, James C. How to Identify and Control Water Weeds and Algae.

Milwaukee: Applied Biochemists, Inc., 1987.

Water pollution

Among the many environmental problems that offend and

concern us, perhaps none is as powerful and dramatic as

water

pollution

. Ugly, scummy water full of debris,

sludge

and dark foam is surely one of the strongest and most easily

recognized symbols of our misuse of the

environment

What is pollution? The verb “pollute” is derived from

the Latin polluere: to foul or corrupt. Our most common

meaning is to make something unfit or harmful to living

things, especially by the addition of waste matter or sewage.

A broader definition might include any physical, biological,

or chemical change in

water quality

that adversely affects

living organisms or makes water unsuitable for desired uses.

Paradoxically, however, a change that adversely affects

one organism may be advantageous to another. Nutrients

that stimulate oxygen consumption by bacteria and other

decomposers

in a river or lake, for instance, may be lethal

to fish but will stimulate a flourishing community of decom-

posers. Whether the quality of the water has suffered de-

pends on your perspective. There are natural sources of water

contamination, such as poison springs, oil seeps, and

sedi-

mentation

from

erosion

, but most discussions of water

pollution focus on human-caused changes that affect water

quality or usability.

1480

The most serious water pollutants in terms of human

health worldwide are pathogenic organisms. Altogether, at

least 25 million deaths each year are blamed on these water-

related diseases, including nearly two-thirds of the mortali-

ties of children under five years old. The main source of

these pathogens is from untreated or improperly treated

human wastes. In the more developed countries,

sewage

treatment

plants and other

pollution control

techniques

have reduced or eliminated most of the worst sources of

pathogens in inland surface waters. The United Nations

estimates that 90% of the people in high-income countries

have adequate sewage disposal, and 95% have clean drinking

water.

For poor people, the situation is quite different. The

United Nations estimates that three-quarters of the popula-

tion in less-developed countries have inadequate

sanitation

and that less than half have access to clean drinking water.

Conditions are generally worse in remote, rural areas where

sewage treatment is usually primitive or nonexistent, and

purified water is either unavailable or too expensive to obtain.

In the 33 poorest countries, 60% of the urban population

have access to clean drinking water but only 20% of rural

people do.

This lack of pollution control is reflected in surface and

groundwater

quality in countries that lack the resources or

political will to enforce pollution control. In Poland, for

example, 95% of all surface water is unfit to drink. The

Vistula River, which winds through the country’s most heav-

ily industrialized region, is so badly polluted that more than

half the river is utterly devoid of life and unsuited even for

industrial use. In Russia, the lower Volga River is reported

to be on the brink of disaster due to the 300 million tons

(272.2 million metric tons) of

solid waste

and 20 trillion

L (5 trillion gal) of liquid

effluent

dumped into it annually.

The less-developed countries of South America, Af-

rica, and Asia have even worse water quality than do the

poorer countries of Europe. Sewage treatment is usually

either totally lacking or woefully inadequate. Low technolog-

ical capabilities and little money for pollution control are

made even worse by burgeoning populations, rapid urbaniza-

tion, and the shift of heavy industry from developed countries

where pollution laws are strict to

less developed countries

where regulations are more lenient.

In Malaysia, 42 of 50 major rivers are reported to be

“ecological disasters.” Residues from palm oil and

rubber

manufacturing, along with heavy erosion from

logging

tropical rain forests, have destroyed all higher forms of life

in most of these rivers. In the Philippines, domestic sewage

makes up 60–70% of the total volume of Manila’s Pasig

River. Thousands of people use the river not only for bathing

and washing clothes, but also as their source of drinking

and cooking water. China treats only 2% of its sewage. Of

Environmental Encyclopedia 3

Water pollution

78 monitored rivers in China, 54 are reported to be seriously

polluted. Of 44 major cities in China, 41 use “contaminated”

water supplies, and few do more than rudimentary treatment

before it is delivered to the public.

Pollution control standards and regulations usually dis-

tinguish between point and nonpoint pollution sources. Fac-

tories,

power plants

, sewage treatment plants, underground

coal

mines, and oil

wells

are classified as point sources

because they

discharge

pollution from specific locations,

such as drain pipes, ditches, or sewer outfalls. These sources

are discrete and identifiable, so they are relatively easy to

monitor and regulate. It is generally possible to divert effluent

from the waste streams of these sources and treat it before

it enters the environment.

In contrast, nonpoint sources of water pollution are

scattered or diffused, having no specific location where they

discharge into a particular body of water. Nonpoint sources

include

runoff

from farm fields,

golf courses

, lawns and

gardens, construction sites, logging areas, roads, streets, and

parking lots. Multiple origins and scattered locations make

this pollution more difficult to monitor, regulate, and treat

than point sources.

Desert

soils often contain high salt concentrations

that can be mobilized by

irrigation

and concentrated by

evaporation, reaching levels that are toxic for plants and

animals. Salt levels in the San Joaquin River in central Cali-

fornia rose about 50% between 1930 to 1970 as a result of

agricultural runoff.

Salinity

levels in the

Colorado River

and surrounding farm fields have become so high in recent

years that millions of acres of valuable croplands have had

to be abandoned. The United States is building a huge

desalination plant at Yuma, Arizona, to reduce salinity in

the river. In northern states, millions of tons of sodium

chloride and calcium chloride are used to melt road ice in

the winter. The corrosive damage to highways and automo-

biles and the toxic effects on vegetation are enormous.

Leach-

ing

of road salts into surface waters has a similarly devasta-

ting effect on aquatic ecosystems.

Acids are released by mining and as by-products of

industrial processes, such as leather tanning, metal smelting

and plating,

petroleum

distillation, and organic chemical

synthesis. Coal mining is an especially important source of

acid

water pollution. Sulfides in coal are solubilized to make

sulfuric acid. Thousands of miles of streams in the United

States have been poisoned by acids and metals, some so

severely that they are essentially lifeless.

Thousands of different natural and synthetic organic

chemicals

are used in the chemical industry to make pesti-

cides,

plastics

, pharmaceuticals, pigments, and other prod-

ucts that we use in everyday life. Many of these chemicals

are highly toxic. Exposure to very low concentrations can

cause

birth defects

, genetic disorders, and

cancer

. Some

1481

synthetic chemicals are resistant to degradation, allowing

them to persist in the environment for many years. Contami-

nation of surface waters and groundwater by these chemicals

is a serious threat to human health.

Hundreds of millions of tons of hazardous organic

wastes are thought to be stored in dumps, landfills, lagoons,

and underground tanks in the United States. Many, perhaps

most, of these sites are leaking toxic chemicals into surface

waters or groundwater or both. The

Environmental Protec-

tion Agency

(EPA) estimates that about 26,000

hazardous

waste

sites will require cleanup because they pose an immi-

nent threat to public health, mostly through water pollution.

Although the oceans are vast, unmistakable signs of

human abuse can be seen even in the most remote places.

Garbage

and human wastes from coastal cities are dumped

into the ocean.

Silt

, fertilizers, and pesticides from farm

fields smothered coral reefs, coastal spawning beds, and over-

fertilize estuaries. Every year millions of tons of plastic litter

and discarded fishing nets entangle aquatic organisms,

dooming them to a slow death. Generally coastal areas,

where the highest concentrations of sea life are found and

human activities take place, are most critically affected.

The amount of oxygen dissolved in water is a good

indicator of water quality and of the kinds of life it will

support. Water with an oxygen content above 8

parts per

million

(ppm) will support game fish and other desirable

forms of aquatic life. Water with less than 2 ppm oxygen will

support only worms, bacteria,

fungi

, and other decomposers.

Oxygen is added to water by diffusion from the air, especially

when turbulence and mixing rates are high, and by

photo-

synthesis

of green plants, algae, and cyanobacteria. Oxygen

is removed from water by

respiration

and chemical pro-

cesses that consume oxygen.

In spite of the multitude of bad news about water

quality, some encouraging pollution control stories are

emerging. One of the most outstanding examples is the

Thames River in London. Since the beginning of the Indus-

trial Revolution, the Thames had been little more than an

open sewer, full of vile and toxic waste products from domes-

tic and industrial sewers. In the l950s, however, England

undertook a massive cleanup of the Thames. More than $250

million in public funds plus millions more from industry were

spent to curb pollution. By the early l980s, the river was

showing remarkable signs of rejuvenation. Oxygen levels

had rebounded and some 95

species

of fish had returned,

including the pollution-sensitive

salmon

, which had not

been seen in London for 300 years. With a little effort, care,

and concern for the environment, similar improvements can

develop elsewhere.

[William P. Cunningham]

Environmental Encyclopedia 3

Water quality

Major pollutants of coastal waters around the United States. (Beacon Press. Reproduced by permission.)

ESOURCES

OOKS

Mayberck, M. Global Freshwater Quality: A First Assessment. Oxford, UK:

Blackwell Reference, 1990.

THER

Protecting Our Future Today. Washington, DC: Environmental Protection

Agency, 1991.

Water quality

Water quality encompasses a wide range of water characteris-

tics, including biological, chemical, and physical descriptions

of water clarity or contamination. Water quality assessment

is typically based on the examination of certain attributes,

conditions or properties of a lake, river, bay,

aquifer

,or

other water body. The most important of these attributes

are pollutants that demand oxygen or cause disease, nutrients

that stimulate excessive plant growth, synthetic organic and

inorganic

chemicals

, mineral substances, sediments, radio-

active substances, and temperature. Since the 1950s, routine

tests for water quality have evaluated temperature, turbidity,

1482

color, odor, total solids after evaporation, hardness (

), and

concentrations of

carbon dioxide

, iron,

nitrogen

, chloride,

active

chlorine

microorganisms

coliform bacteria

, and

amorphous matter. In recent years increasing contamination

and growing public concern over water quality have led to

the addition of a number of additional parameters, including

algal growth,

chemical oxygen demand

, and the presence

hydrocarbons

, metals, and other toxic substances.

Water quality is evaluated through a set of samples

taken from a cross-section of a body of water. Because quality

conditions change continually, each set of samples is under-

stood to represent conditions at the time of sampling. Long-

term water quality monitoring requires periodic data collec-

tion at regular sampling stations. In order to ensure that

quality measurements are consistent at different times and

locations, standards are legally set for various water uses and

contaminant levels. There are two general types of standards

for measuring water quality. “Water quality based standards”

are set to ensure that a water body is clean enough for its

expected uses, e.g., fishing, swimming, industrial use, or

drinking. “Technology based standards” are set for

waste-

Environmental Encyclopedia 3

Water quality

water

entering a water body so that overall water conditions

remain acceptable. These standards have been developed

worldwide. In the United States, the

Environmental Pro-

tection Agency

(EPA) is responsible for developing

water

quality standards

and criteria for surface, ground, and

marine waters.

Water quality standards, ambient conditions of a water

body that meet expected uses, are based upon water quality

criteria. These criteria designate acceptable levels of specific

pollutants, clarity, or oxygen content. Usually acceptable

levels of these criteria are measured in

parts per million

(ppm) of each contaminant or

nutrient

. These measure-

ments allow scientists to assess whether or not a body of

water meets the prescribed water quality standards. If stan-

dards are not met, then local governing bodies or industries

must develop and implement cleanup strategies that target

specific criteria. In the United States and many other coun-

tries, national water quality criteria have been developed for

most conventional, toxic, and non-conventional pollutants.

Conventional pollutants include suspended solids,

biochem-

ical oxygen demand

(BOD), pH (acidity or alkalinity),

fecal coliform bacteria, oil, and grease. Toxic priority pollut-

ants include metals and organic chemicals. Non-conven-

tional pollutants are any other contaminants that harm hu-

mans or marine resources and require regulation.

Drinking water must meet especially high standards to

be safe for human consumption, and its quality is strictly mon-

itored in the United States and most heavily populated regions

of the world. Most governments have a legal responsibility to

maintain acceptable drinking water quality. Until 1974, ef-

forts to maintain acceptable levels of drinking water quality

in the United States were limited to preventing the spread of

contagious diseases. The

Safe Drinking Water Act

of 1974

expanded the government’s regulatory role to cover all sub-

stances that may adversely affect human health or a water bo-

dy’s odor or appearance. This act established national regula-

tions for acceptable levels of various contaminants.

Both point and nonpoint sources of

pollution

affect

water quality. Point sources are discrete locations that

dis-

charge

pollutants, mainly industrial outflow pipes or

sew-

age treatment

plants. Nonpoint sources are more diffuse,

and include

storm runoff

and

runoff

from farming,

log-

ging

, construction, and other

land use

activities.

In the United States, over 50% of the population relies

on underground sources for drinking water. Because

groundwater

receives an enormous range of agricultural,

industrial, and urban pollutants, groundwater quality is an

issue of growing concern. Preventing

groundwater pollu-

tion

is especially important because remedial action in an

aquifer is expensive and technologically difficult. Major

sources of groundwater pollution include nitrate contamina-

tion from septic systems, organic pollutants from leaking

1483

fuel tanks and other storage containers, and an array of

contaminants leached from landfills.

In rivers, the most extensive causes of water quality

impairment are usually

siltation

, nutrient concentration (ni-

trogen and

phosphorus

), fecal coliform bacteria, and low

dissolved oxygen

levels caused by high organic content

(sewage, grass clippings, pasture and

feedlot runoff

, etc.).

Agricultural runoff including pesticides, fertilizers, and sedi-

ments is the largest source of river pollution, followed by

municipal sewage discharge. Estuaries, rich ecosystems of

mixed salt and fresh water where rivers enter a sea or ocean,

often have serious water quality problems. Estuarine contam-

inants are usually the same as those in rivers—high organic

content and low oxygen, disease-causing pathogens, organic

chemicals, and municipal sewage discharge.

In most lakes, water quality is affected primarily by

nitrogen and phosphorus

, siltation and low dis-

solved oxygen. Like rivers, lakes suffer from agricultural

runoff,

habitat

modification, storm runoff, and municipal

sewage

effluent

. Lakes especially suffer from eutrophication

(the excessive growth of aquatic algae and other plants)

caused by high levels of nutrients. This burst of growth, also

called an

algal bloom

, feeds on concentrated nutrients.

Thick mats of algae and other aquatic plants clog water

systems, increase turbidity, and suffocate aquatic animals so

that an entire

ecosystem

is disrupted. Of the lakes assessed

by the U.S. Environmental Protection Agency’s 1988 Na-

tional Water Quality Inventory, one-third were affected by

eutrophication. In some lakes, especially the

Great Lakes

the presence of persistent toxic substances is an additional

concern. Most of these

toxins

originate in the industrial

regions that surround these lakes or in the heavy shipping

traffic between lakes.

Water quality degradation affects the

stability

aquatic ecosystems as well as human health. Much is still

unknown about the effects of specific pollutants on

ecosys-

tem health

. However, fish and other aquatic organisms

exposed to elevated levels of pollutants may have lowered

reproduction and growth rates, diseases, and, in severe cases,

high death rates. See also Cultural eutrophication

[Marci L. Bortman Ph.D.]

ESOURCES

OOKS

Becker, C. D., ed. Water Quality in North American River Systems. Colum-

bus, OH: Battelle Press, 1992.

Cotruvo, J. A., and E. Bellack. “Maintaining Drinking Water Quality.” In

Perspectives on Water, edited by D. H. Speidel, et al. New York: Oxford

University Press, 1988.

Eckenfelder Jr., W. W. Principles of Water Quality Management. Boston:

CBI Publishing, 1980.

Environmental Encyclopedia 3

Water quality standards

THER

U.S. Environmental Protection Agency. National Water Quality Inventory

1988 Report to Congress. Washington, DC: U.S. Government Printing

Office, 1990.

U.S. Environmental Protection Agency. The Quality of Our Nation’s Water.

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

Water quality standards

The development of

water quality

standards is a process

first mandated by the Water Quality Act of 1965 and contin-

ued by requirements in the Federal

Water Pollution

Control

Act of 1972 (PL 92-500), with amendments in 1977, 1982,

and 1987 (collectively referred to as the

Clean Water Act

The process is used to establish standards for stream water

quality by taking into account the use and value of a stream

for public water supplies, propagation of fish and

wildlife

recreational purposes, as well as agricultural, industrial, and

other legitimate uses. Water quality standards are enforce-

able by law and are applicable to all navigable waters. The

goals of water quality standards are to protect public health

and the

environment

, and to maintain a standard of water

quality consistent with its designated uses. Water quality

standards provide the “teeth” for water quality legislation and

also the yardstick by which performance may be evaluated.

To establish water quality standards for a water body,

officials (1) determine the designated beneficial water use;

(2) adopt suitable water quality criteria to protect and main-

tain that use; and (3) develop a plan for implementing and

enforcing the water quality criteria. Both uses and criteria

constitute water quality standards, and water quality is evalu-

ated based on how well the designated uses are supported.

Appropriate water use is designated by analyzing the

existing use of the water as well as the potential to attain

other uses based on an assessment of the physical, chemical,

biological, and hydrological characteristics of the water and

the economic cost and impact of achieving particular uses.

The Clean Water Act requires that, whenever possible, water

quality standards should ensure the protection and propaga-

tion of fish, shellfish, and wildlife and should provide for

recreation

in and on the stream. States have primary respon-

sibility for designating stream segment uses, so stream uses

may vary from state to state. However, stream use as desig-

nated by one state must not result in the violation of another

state’s use of the same stream.

Water quality criteria are most often expressed as nu-

meric constituent concentrations or levels, but may be narra-

tive statements if numeric values are not available or known.

Each criterion is based on scientific information available

concerning the effect of the pollutant on human health,

aquatic life, and aesthetics.

Before the passage of the Clean Water Act, water

pollution control

efforts were considered successful if they

1484

achieved water quality standards. However, under the act,

the accepted measurements of successful water

pollution

control is whether the

effluent

from point sources, specifi-

cally Publicly Owned Treatment Works (POTWs), meets

technology-based effluent standards. These standards are

based on what can be done with available technology rather

than what is required to achieve water quality standards.

Water quality standards were retained, however, as

part of the overall strategy to control water pollution. Rather

than using water quality standards as the highest goal for

determining water quality, the state and federal authorities

consider water quality control standards to be the lowest

acceptable level of water quality. In addition, point sources

may be subjected to more stringent requirements than the

use of

Best Available Control Technology

(BAT) if neces-

sary to meet water quality standards. For example, in stream

segments that do not meet water quality standards, states

can establish a “total maximum daily load” of pollutants that

will achieve water quality standards and assign a permissible

share to individual dischargers. State water quality programs

must also include provisions to prevent degradation of ex-

isting water quality when necessary to maintain existing uses

and certain high quality waters.

The attainment of water quality standards is also af-

fected by control of pollution from nonpoint sources, such as

agricultural practices that result in the addition of sediments,

nutrients, pesticides, and other contaminants to water bod-

ies. The 1987 amendments to the Clean Water Act required

states to identify water not meeting its standards due to

nonpoint source

pollution, identify general and specific

nonpoint sources causing the problems, and develop man-

agement plans for the control of the these sources.

In 1988, state governments compiled a water quality

report for the

Environmental Protection Agency

(EPA).

The report indicated that of 519,412 river miles (835,734

km) assessed (out of a total of 1.8 million mi [2.9 million

km] in the United States) 10% did not support their desig-

nated uses, 20% partially supported their uses, and 70%

fully supported their uses. For lakes, of 16,313,962 acres

(6,525,585 ha) assessed (out of a total of 39,400,000 acres

[15,760,000 ha] in the United States), 10% did not support

their designated uses, 17% partially supported their uses,

and 74% fully supported their uses. See also Agricultural

pollution; Agricultural runoff; Criteria pollutant; Marine

pollution; Thermal pollution

[Judith Sims]

ESOURCES

OOKS

Abron, L. A., and R. A. Corbitt. “Air and Water Quality Standards.” In

Standard Handbook of Environmental Engineering, edited by R. A. Corbitt.

New York: McGraw-Hill, 1990.

Environmental Encyclopedia 3

Water reclamation

THER

The Universities Council on Water Resources. “The Clean Water Act.”

Water Resources Update 84. Carbondale, IL: Southern Illinois University,

1991.

Water reclamation

Theterm “water reclamation” canbe defined in differentways.

In the early and mid-1900s, water

reclamation

referred pri-

marily to supplying potable water to

arid

areas where water

was not readily available, through the development of water

projects such as

dams

and canals. Water reclamation can also

mean collecting used water (i.e.,

wastewater

) and treating

it for

reuse

for

irrigation

and other purposes.

The federal agency primarily responsible for water rec-

lamation projects that provided a source of water to arid lands

isthe

BureauofReclamation

,in the Departmentof the Inte-

rior. Formed in 1902 as the Reclamation Service and later

renamed the Bureau of Reclamation in 1923, the agency’s

mission was “the construction and maintenance of irrigation

works for the storage, diversion, and development of water

for the reclamation of arid and semi-arid lands.” This federal

agency built dams, reservoirs, and other water development

projects in the 17 western states of the United States. The

mission of the Bureau of Reclamation in the early 1900s was

to serve the irrigation needs of farms of 160 acres (65 ha) or

less. By the 1930s thebureau’s constituency expanded to larger

farms, towns, and cities. The

Army Corps of Engineers

and

the Department of Agriculture

Soil Conservation Service

(now called the

Natural Resources Conservation

Service)

are also responsible for providing irrigation water in addition

to providing flood control,

drainage

, and navigation.

During the early 1900s, water reclamation projects were

a means of providing an opportunity for people to settle in

the western United States. The projects provided inexpensive,

government-subsidized water used for

transportation

farming, industry, and by municipalities for drinking water

and electricity. During the Depression era of the 1930s, the

Bureau of Reclamation and the Public Works Administration

worked together on water projects, which became an impor-

tant part of the nation’s economic recovery program.

In 1959, a Senate Select Committee on National

Water

Resources

was formed to determine whether more water

projects were necessary. After two years of investigations, the

committee highlighted three main concerns: possible water

shortages in the future, decreasing

water quality

, and possi-

ble

flooding

. Some of the recommendations made by the

committee to address these concerns included increased regu-

lation of stream flows by reservoirs, improved

groundwater

use, improvements in water use efficiency, and increased use

of desalination and

weather modification

1485

As a follow-up to the recommendations by the Select

Committee on Natural Water Resources, President Kennedy

created a Water Resources Councilheaded up by the Secretar-

ies of the Interior, Health, Education and Welfare, and the

Army to make biennial nationwide water project studies and

to develop uniform regulations for evaluating water projects.

With the advent of the environmental movement during the

1960s and the lowered unemployment relative to the 1930s,

water reclamation projects became less of a national priority.

By the 1970s, President Carter proposed that the costs of

water projects be shared by the local water users. President

Carter also proposed that water reclamation projects be evalu-

ated based on economic, environmental, and safety criteria.

DuringPresident Reagan’s tenure, the criteriaused to evaluate

the feasibility of water projects were relaxed; however, Presi-

dent Reagan continued support of local cost sharing.

Over the years, there have been numerous water recla-

mation projects. A year after the formation of the Bureau of

Reclamation,the agency was workingon six projects. By1907,

it was participating in the development of 27 water projects.

From 1905-1991, the Bureau of Reclamation built over 493

reservoirs and diversion dams, 7,670 mi (12,341 km) of irriga-

tion canals, 1,440 mi (2,317 km) of pipelines and tunnels, and

53 hydroelectric

power plants

. All the larger rivers in the

U.S. have been altered in some way by water reclamation proj-

ects. For example, the Columbia River has 28 dams. Some

of the larger water reclamation projects include the Central

Arizona Project (a massive canal system that diverts over 1.2

million acre-feet [1.5 billion m

] of water per year from the

Colorado River

), Bonneville Dam in Oregon, Grand Coulee

Dam in Washington, Marshall Ford Dam in Texas, Teton

Dam in Idaho, Garrison Dam in North Dakota,

Tellico Dam

in Tennessee, Hoover Dam in Nevada,

Glen Canyon Dam

Arizona, Imperial Dam in California, and the Central Valley

Project in California. Costs of these projects were large. For

example, the California Central Valley Project cost over $950

million. The farmers, large and small, have paid only a small

portion of overall costs of water reclamation projects. An esti-

mated 4% of the total cost of the California Central Valley

Project, equal to about $38 million, was repaid by the farmers

who benefitted from the water project.

Important

wildlife habitat

and wildlife were lost as

a result of these efforts to create massive dams. Dam building

along the Colorado River has led to the decline of eight

species

of fish that are now considered Endangered. Habitat

loss can result from flooding areas to create reservoirs or

from cutting off water and nutrients from naturally occurring

periodic flooding. During dam construction, stream-side

habitat communities can be altered and destroyed from di-

verting the course of the river and excavation and

dredging

activities related to dam building. The

ecology

of these

Environmental Encyclopedia 3

Water resources

areas typically changes from that of a river to that commonly

found along lakes and reservoirs.

Another ecological change occurs from dams cutting

off

sediment

suspended in rivers from flowing downstream.

As a result, sediment builds up in dams, reducing their

volume and lowering their life expectancy. For example, the

volume of Lake Waco in Texas was reduced by half over a

34-year period. When dams trap

silt

and sediment,

erosion

can result down stream. Below the Hoover Dam, millions

of cubic yards of sediment were eroded over a 100 mi (160

km) stretch of the Colorado River.

Water reclamation projects continue on a much smaller

scale today. Another method in which to obtain water for irri-

gation purposes is using water twice—once for domestic pur-

poses and a second time for irrigation of lands such as farms

and

golf courses

. Reclaiming used water occurs in the U.S.

and throughout the world. Israel reclaims over 70% of its used

water, or waste water, to irrigate over 47,000 acres (19,000 ha)

of farm land. By the end of the 1990s, Israel plans to supply

over 16% of its total water needs by reclaiming waste water.

The city of Los Angeles, California, reuses its treated waste

water to recharge its underground aquifers, which it taps for

drinking water. In Arizona, the city of Tucson plans to reuse

water to meet over 19% of its total water needs while Phoenix

receives over 70,640 ft

(2,000 m

) of fresh water from the

Bureau of Reclamation in exchange for every 105,960 ft

(3,000 m

) of reclaimed water used by the nearby irrigation

district. The city of St. Petersburg, Florida, has a unique sys-

tem in which it provides two sources of water; one source is

potable water used for drinking, cooking, washing, etc. and

the other source of water is reclaimed water from wastewater

that is reused for irrigating parks, median strips along roads,

andresidential lawns. Becausethe treated wastewatercontains

nutrients such as

nitrogen

and

phosphorus

, less

fertilizer

needed when used for irrigation.

Securing sufficient amounts of water while sustaining

a healthy

environment

can be accomplished in many ways

using all types of water reclamation projects including waste

water reuse.

Water conservation

, efficiency of use, and

reuse will likely be playing larger roles in ensuring adequate

water supplies in the future.

[Marci L. Bortman]

ESOURCES

OOKS

Gottlieb, R. A Life of Its Own, The Politics and Power of Water. New York:

Harcourt Brace Jovanovich, 1988.

Hunt, C. E., and V. Huser. Down by the River, the Impact of Federal

Water Projects and Policies on Biological Diversity. Washington, DC: Island

Press, 1988.

Outwater, A. Water, A Natural History. New York: Basic Books, 1996.

1486

Postel, S. Last Oasis: Facing Water Scarcity. The Worldwatch Environmental

Alert Series. New York: W.W. Norton & Company, 1992.

Water resources

Water resources represent one of the most serious environ-

mental issues of the twentieth century. Water is abundant

globally, yet millions of people have inadequate fresh water,

and droughts

plague

rich and poor countries alike.

Water

pollution

compounds the

scarcity

of usable fresh water and

threatens the health of millions of people each year. At

the same time, the ravages of

flooding

and catastrophes

associated with excessive rainfall or snowmelt cause death

and destruction of property. To cope with these problems,

water resource management has become a high priority

worldwide.

Concerns about water scarcity seem unwarranted, con-

sidering that there are 326 million mi

(1.36 billion km

)

of water on earth. Although 99% of this water is either

unusable (too salty) or unavailable (ice caps and deep

groundwater

storage), the remaining 1% can meet all future

water needs. The total volume of fresh water on earth is not

the problem. Scarcity of fresh water results from the unequal

distribution of water on earth and water

pollution

that ren-

ders water unusable.

Fresh water is not always available where or when it

is needed the most. In Lquique, Chile, for example, no

rainfall was measured for 14 consecutive years, from 1903

to 1918. At the other extreme, Mount Waialeale, Kauai,

Hawaii, averages 460 in (1,168 cm) of rainfall per year.

Even such extremes in annual precipitation do not tell the

complete story of water scarcity. For example, in the tropics,

storms in the rainy season can deposit from 16 to over 39

in (40.6 to 99 cm) of rainfall in two to three days, often

resulting in widespread flooding. However, the same areas

can experience negligible rainfall for two to three months

during the dry season.

The demand for water varies worldwide, with wealth-

ier countries consuming an average of about 264,000 gallons

(1,000 m

) per person, per year. In contrast, over one-half

of the population in the developing countries of North Africa

and the Middle East live on a fraction of this amount.

Population growth

and droughts have forced people to use

water more efficiently. However,

water conservation

alone

will not solve water scarcity problems.

Increasing demands for water and the disparity of

water distribution have sparked the imagination of hydrolo-

gists and engineers. Grandiose schemes have emerged, in-

cluding towing icebergs from polar regions to the lower

latitudes,

desalinization

of ocean water, cloud seeding, and

transporting water thousands of kilometers from water-rich

to water-poor regions. Although many of these ideas are