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
- Water Pollution
- Why Should You Care�About Water Pollution?
- The Earth’s Water Supply
- Water as Habitat
- Marine Aquatic Systems
- Freshwater Aquatic Systems
- Freshwater Aquatic Systems
- What Are the Problems?�Human Impacts on Natural Cycles
- Sources of Water Pollution
- Pollution of Rivers Lakes
- Pollution of Lakes
- Ocean Pollution
- Ocean Pollution
- Groundwater Pollution
- What Can Be Done?�Clean-up versus Prevention
- Legal Measures
- Technological Solutions
- Technological Solutions
- Economic and Political Solutions
- What Would You Do?