I. Fresh Water

V. Water Speciation

I. Fresh Water

Use

Fresh water withdrawal increases 4 - 8 % per year

Globally 3,240 cubic kilometers of fresh water are withdrawn yearly.

69% Agriculture (~25% is returned as waste water)
23% Industry
8% Domestic

Annual per capita water use

Location	Cubic Meters
North & Central America	1,692
Europe	726
Asia	526
South America	476
Africa	244

(Ref: "World Resources 1992-1993 a guide to the global environment", Report by the World Resources Institute, in collaboration with the United Nations Environment Programme and the United Nations Development Programme, NY, 1992. ISBN 0-19-506230-2)

Categories of Water Pollution

1. Biological agents that cause Disease
   Bacteria, Viruses, Parasites

2. Oxygen demanding wastes
   Usually organic materials
   (Dissolved Oxygen, DO; Biological Oxygen Demand, BOD is common test of water quality)

3. Water soluble inorganic chemicals
   salts, acids, metal ions

4. Plant nutrients (usually Inorganic)
   Phosphates, Nitrates, etc.

5. Organic chemicals
   Pesticides, Solvents, Detergents, Oil, Grease, Gasoline, (carcinogens), etc.
   (note: > 700 Synthetic organic molecules identified in natural waters thus far)

6. Suspended solids and sediments
   Soil, Insoluble Particles

7. Radioisotopes
   Carcinogens
   (note: some occur naturally, K-41, Th-230, U-238, etc.)

8. Heat
   Industrial and municipal cooling (O2 range 9-4 ppm)
   (note: O2 solubility is temperature dependent parameter)

9. Combinations
   a single source can contribute all pollution categories,
   (note: Municipal sewage treatment plants release 1- 8 simultaneously, etc.)
   

Some thoughts on the nature of reversibility of water pollution:

Natural water systems may recover in many cases if:

1. Quantity of pollution is limited

2. Pollution occurs over a short period of time

3. Impact is not overly stressful to balance of the ecosystem

4. Ecosystem is equipped to handle the specific pollutant
   (Ex. equipped with appropriate bacteria to degrade an organic molecule)

5. Other pollutants do not have detrimental synergistic effect

Natural water systems cannot recover if:

1. There is no pathway or natural mechanism to decontamination
   (Ex. CFCs, Radioisotopes, C-F bond, Metal Ion Poison Overload)

2. Overload critically damages or over stresses the ecosystem

3. Synergistic effects of several pollutants are acting simultaneously

4. Serialize ecosystem

5. Effect long term equilibrium system
   (Ex. gasoline contamination of an aquifer, why?)

6. What other scenarios?

Sources of Water Pollution

1. Point

2. Nonpoint

Water pollution damage estimated in US per year - $20 Billion.

Major sources

1. Waste water Discharge & Industrial Eff.	Point Source
2. Land-Use Runoff	Nonpoint Source
3. Atmospheric Deposition	Nonpoint Source
4. Mine Leaching	~Point Source
5. Landfill Leaching	~Point Source

Point and nonpoint sources of water pollution.

Nonpoint Sources

Examples of Nonpoint Sources

• Agricultural runoff - chemicals, pesticides, sediments

• Logged forests

• Urban runoff

• Suburban runoff - Septic tanks

• Acid deposition

• Roadway runoff

Major source of Nonpoint Water Pollution -
Agriculture is responsible for > 60% of total mass of water shed pollution

U.S. industrial emissions of 2,400,000,000 kg into the air come back as fresh water as rain born nonpoint source pollution each year.

Nonpoint source is the least controlled

Why?

Point Sources

Point Sources account for 9% of U.S. surface water pollution

Examples of Point Sources

• Industrial discharge - waste water, chemicals, heat

• Municipal Sewer Treatment

• Ditches

• Mines

• Oil wells and Tankers

Major constituents:

1. Synthetic organic chemical
2. Transition and "heavy" metal ions

1988 Industry Discharged 425,000,000 kg of toxic chemicals directly in to water sources

Chemical assault on major U.S. coastal areas.

Ocean Pollution

All water flows to the sea (ocean)

Problem of the "Commons Mentality"

The U.S. is responsible for > 1/3 of all trash and waste dumped in the Oceans.

Nonvolatile soluble and non-soluble organics and inorganics accumulate.

Pathways to pollution elimination from the oceans

persistence in the environment
stability breakdown from UV, chemical interaction etc.
biological degradation
biological uptake intact - bio-accumulation

Inorganic Molecules and Ions

(elements don't go away, they are here forever)
persistence in the environment
molecular alteration, species change (bonds or charge)
biological uptake intact - bio-accumulation

The oceans are to big to harm philosophy

Globally, annual deposits of eutrophing nutrients are dumped
7 - 35 million metric tons of dissolved nitrogen and
0.6 - 3.8 million metric tons of dissolved phosphorous

Over fertilized oceans cause algae blooms that deplete oxygen as they decay

Promote toxic algae that kill fish, invertebrates, and coral reefs.

Raw Sewage is dumped directly into oceans

Infections such as hepatitis, cholera, typhoid, and other human pathogens are available to return to man by:

1. Recreational use of Ocean water
2. Eating of contaminated sea food.

Most of the discharge is in coastal water were the bulk of both the recreational and fishing are done.

Engineered dumping:
Most coastal areas flush sewage with each precipitation event.

Separated and combined storm and sewer systems.

Major sources of groundwater contamination in the United States.

Inorganic Heavy Metals -

These element are bio-accumulated in the food web.

The NOAA (U.S. National Oceanic and Atmospheric Administration Mussel Watch program has monitored the decline of Pb in mussels and oysters along the U.S. coast with the reduction of leaded gasolines in the late 1970's

Synthetic Organic Chemicals also bio-accumulate -

Sediment

Synergistic effect of sediment -
In addition, high levels of contaminants including pesticides and fertilizers bind to sediment particles, move with the sediment particles, and settle out in shallow estuaries or coastal waters. Causing a double threat.

Notice that cities are located near water and the ocean coasts
By the year 2000, 1 billion people will live in coastal cities

The land and water are linked and are not separate unrelated entities.

Coastal areas such as the Chesapeake Bay may retain > 95% of the nutrients and pollutants that enter that water shed.

Other Ocean Dumping

Dredge Spoils

Etc.

Oil Pollution

Some heavy oil components sink and destroy coral and sea bed organisms

Floating oil can destroy photosynthetic organisms, fish, mammals, and birds.

Natural crude is more easily reclaimed by bacteria in ocean water

Where does Ocean Oil come from?

• Up to 90% of oil reaching oceans is dumped on land carelessly
• Oil well blowouts
• Drilling operations
• Tanker cargo cleaning and ballast dumping
• Tanker accidents
  Tanker accidents account for only 10-15% of oil in ocean

Methods of dealing with oil slicks and beach bound oil are ineffectual Case studies of accidents are informative:

Gulf war - 200 yr recovery - deadened bay
Exxon Valdez
Castillow Bellver - Capetown, South Africa
Barge Florida - Cape Cod
etc.

Why not rush to make "Super Bugs" that consume oil faster?
Haven't we done things like this before?
(Ozone - how could a non-toxic and relatively inert molecule hurt anything)

Ocean Oil Prevention and Cleanup
What are the answers?

Who is responsible? Who can enforce? Social conscience?

Exxon Valdez oil spill in Alaska's Pince William Sound.

The Great Lakes Basin.

Chesapeake Bay.

Major sources of nutrient overload from human activities.

The oxygen sag curve vs. oxygen demand.

Wet and dry cooling towers.

Notes Table of Contents

Introduction to Environmental Science Home Page

Duquesne University Home Page

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Created and maintained by
Jim Ferguson
Revised 11/30/95.