WATER POLLUTION

Lecture 16

HUMANS AND MUCH OF LIFE DEPENDS ON WATER

– ABUNDANT BUT FINITE SUPPLY

– CONTINUALLY RECYCLED AND PURIFIED

WATER POLLUTION

– CHANGE IN WATER WITH HARM TO HUMANS OR OTHER ORGANISMS

MAJOR THREAT TO HUMAN HEALTH

SPREAD OF DISEASE

TOXIC MATERIALS

WHY SHOULD YOU CAREABOUT WATER POLLUTION?

THE EARTH’S WATER SUPPLY

WATER COVERS ABOUT 73% EARTH SURFACE

– 0.024% OF TOTAL WATER AVAILABLE

– REMAINDER SALTY, TOO DEEP OR FROZEN

– 30% AVAILABLE FRESHWATER IN AQUIFERS

– HALF WORLD DRINKING WATER

– 25% WATER USED IN U.S.

 WATER NOT EVENLY DISTRIBUTED

MANY DON'T HAVE ACCESS TO ENOUGH

WATER HABITAT FOR MANY ORGANISMS

– AQUATIC LIFE ZONES

– MARINE AQUATIC SYSTEMS

– – FRESHWATER AQUATIC SYSTEMS

 LAYERS OF WATER DIFFERENT PROPERTIES

– UPPER WARMER WITH LIGHT

– MIDDLE SOME LIGHT, COLDER

– DEEPER DARK, COLD

– DISSOLVED OXYGEN

WATER AS HABITAT

MARINE AQUATIC SYSTEMS

LARGEST AQUATIC SYSTEM

 FOUR OCEANS

– PACIFIC (LARGEST)

– ATLANTIC

– ARCTIC

– INDIAN

MARINE ZONES

– COASTAL ZONE

– OPEN SEA

– OCEAN BOTTOM

FRESHWATER AQUATIC SYSTEMS

TWO TYPES

STANDING BODIES

– LAKES, PONDS

– INLAND WETLANDS

– HIGH BIODIVERSITY

– ABSORB WATER

– MANY FORMED BY GLACIERS

– CLASSIFIED BY AMOUNTS OF NUTRIENTS

• EUTROPHIC OR OLIGOTROPHIC

FRESHWATER AQUATIC SYSTEMS

FLOWING SYSTEMS

– RIVERS AND STREAMS

– WATERSHED OR DRAINAGE BASIN

– SOURCE ZONE

– TRANSITION ZONE

– FLOODPLAIN ZONE

WHAT ARE THE PROBLEMS?HUMAN IMPACTS ON NATURAL CYCLES

THREE MAJOR IMPACTS

1. FRESHWATER TAKEN FROM STREAMS, LAKES, AND AQUIFERS

– OFTEN FASTER THAN REPLACEMENT

2. CLEAR LAND AND MAKE IMPERMEABLE TO WATER

– FASTER RUNOFF

– SLOWER RECHARGE OF AQUIFERS

3. DRAINING AND FILLING WETLANDS

– NATURAL "SPONGES"

– RUNOFF INCREASES

 SUBSTANCES DUMPED INTO WATER CAN REDUCE USEFULNESS

– DRINKING, FISHING, SWIMMING, IRRIGATING & OTHER USES OF WATER

POLLUTANT SOURCE

– POINT

– NONPOINT

SOURCES OF WATER POLLUTION

POLLUTION OF RIVERS LAKES

 HALF OF WORLD’S 500 RIVERS HEAVILY POLLUTED

– UNTREATED SEWAGE

– INDUSTRIAL WASTE

 DEVELOPING COUNTRIES

• CHINA'S RIVERS

-1/2 CAN'T BE USED FOR ANY PURPOSE

• INDIA’S RIVERS

-275 OUT OF 445 SEVERELY POLLUTED

 WATER POLLUTION OFTEN REVERSIBLE

– REMOVE SOURCE OF POLLUTION

– BIODEGRADABLE POLLUTANTS

– NONBIODEGRADABLE

POLLUTION OF LAKES

LAKES AND RESERVOIRS LESS EFFECTIVE AT DILUTING POLLUTANTS THAN STREAMS

-STRATIFIED LAYERS WITH LITTLE VERTICAL MIXING

-LITTLE OR NO WATER FLOW

-CAN TAKE UP TO 100 YEARS TO FLUSH AND CHANGE THE WATER IN A LAKE

-BIOLOGICAL MAGNIFICATION OF POLLUTANTS

OCEAN POLLUTION

37% WORLD 40% U.S. LIVE NEAR SEA

– HUMAN IMPACTS ON OCEAN WATERS

– 80-90% LESS DEVELOPED COUNTRIES SEWAGE DIRECTLY DUMPED

 EXCESS NUTRIENTS

– MICROBES

– OXYGEN-DEMANDING WASTES

– OXYGEN DEPLETED ZONES

OCEAN POLLUTION

 EXCESS NUTRIENTS- OXYGEN DEPLETED “DEAD” ZONES- MISSISSIPPI RIVER DISCHARGE

 CORAL REEFS VERY SUSCEPTIBLE- SLOW GROWTH- FAIRLY SHALLOW WATER

 OIL POLLUTION- LARGE AND SMALL SPILLS- RUNOFF FROM CITIES

 PLASTIC- GREAT PACIFIC GARBAGE PATCH

GROUNDWATER POLLUTION

MUCH OF WORLD DEPENDS ON GROUNDWATER

– DRINKING AND IRRIGATION WATER

POLLUTANTS

– FERTILIZERS, PESTICIDES

– GASOLINE, OIL, PAINT THINNERS

– SEPTIC SYSTEMS

– WASTE PONDS

– UNDERGROUND STORAGE TANKS

WHAT CAN BE DONE?CLEAN-UP VERSUS PREVENTION

TWO WAYS CLEANUP OR PREVENTION

– PREVENTION BETTER

– ONLY 15% OF OIL SPILLS RECOVERED

– DAMAGE BEFORE CLEANUP

– BETTER REGULATIONS

– GROUNDWATER IS PARTICULARLY HARD TO CLEAN UP

LEGAL MEASURES

WATER POLLUTION MAJOR POLITICAL PROBLEM

– U.S. CLEAN WATER ACT

• PERMISSIBLE POLLUTANT LEVELS

– PERCENT WASTEWATER TREATMENT

• INCREASED FROM 33% TO 75%

– SAFE STREAMS INCREASED 33-60%

– NATIONAL AND INTERNATIONAL LAWS

– OIL TANKERS

TECHNOLOGICAL SOLUTIONS

NONPOINT-SOURCE POLLUTION DIFFICULT

– DIFFICULT TO ENFORCE A LAW

• IDENTIFICATION OF RESPONSIBLE PARTY HARD

• LARGE AREA

– LANDSCAPE APPROACH

• KEEP CROPLAND VEGETATED

• FENCE OUT LIVESTOCK

• WISE USE OF FERTILIZERS

TECHNOLOGICAL SOLUTIONS

WASTEWATER OR SEWAGE TREATMENT PLANTS

• PRIMARY SEWAGE TREATMENT• PHYSICAL PROCESS

• SECONDARY SEWAGE TREATMENT• BIOLOGICAL PROCESS USING BACTERIA

• TERTIARY OR ADVANCE SEWAGE TREATMENT • SPECIAL FILTERING PROCESSES

• BLEACHING AND DISINFECTION

ECONOMIC AND POLITICAL SOLUTIONS

LEGAL REQUIREMENTS OFTEN SPUR TECHNOLOGY

– DISCHARGE TRADING POLICY

– PERMITS FOR DISCHARGE INTO WATERWAYS

– ABILITY TO POLLUTE CAN BE SOLD AND TRADED

– CREATES A MARKET

– CAPS LOWERED EVERY FEW YEARS

WHAT WOULD YOU DO?

Mindful of water use

• use only needed water

• no dumping of harmful substances

• no yard waste in stream

Personal choices

• buy from companies with good policies

• only activities that minimize pollution

• use manure or compost, not fertilizers

Social activity

• talk about water pollution

• support politicians with good policies

• emphasize preventing pollution