• 44% of lakes, 37% of rivers, 32% estuaries = unsafe for recreational activities

• 75% of H2O pollution in US comes from – Soil erosion– Atmospheric deposition– Surface runoff

• Less- developed countries dump ~95% of all sewage into waterways– Lack of $– Rapid urbanization– Explosive population– More-developed countries shift industry for

cheap labor

• 50% of US depends on GW• 43% of US agriculture water• 100,000 LUSTs (Leaking Underground

Storage Tanks) leak chemicals into GW• 60% of most hazardous liquid waste injected

into GW wells– Remains for average of 1400 years– Cleanup of 300,000 sites could cost $1 trillion

• Biological• Physical• Chemical

• Physical, or chemical change that has a negative impact on human health or the environment

• Consists of pathogens (disease-causing agents)• Come from sewage• Diseases include;

– Typhoid, cholera, dysentery, polio, infectious hepatitis, salmonella, E-Coli bateria

• 1993 Milwaukee Wisconsin – 370,000 developed diarrhea from water-borne pathogen in public drinking water supply

Fish need oxygen to breath – DISSOLVED OXYGEN – or DO. When the DO is low the

fish may suffocate – result = fishkill. Likewise – if the DO is too high, DO in the fish’s blood begins to bubble causing Gas Bubble Disease.

Many factors effect the DO in aquatic environments – temperature, water movement,

aquatic plant life – Pollutants in the water may indirectly effect these three important

factors – temperature, water movement and aquatic plant life, resulting in low water

quality

• DO gets into the water by:– 1) moving water (riffles, rapids, water falls,

etc.)– 2) photosynthesis of aquatic plants

• Gases do not readily dissolve in liquids with high temperatures.

↑T → ↓ DO

• BOD – Biological Oxygen Demand• The amount of oxygen needed for microorganisms to

break down waste material• High BOD indicates high levels of organic

contaminants in the water• Sewage = organic wastes; decomposers work to break

down the waste – which takes oxygen; • ↑ BOD → ↓ DO• Sewage also contains many pathogens – fecal

coliform test performed on water samples

• Referred to as Thermal Pollution• Gases do not readily dissolve in liquids with high

temperatures.↑T → ↓ DO

Power plants sometimes use waterways to cool their equipment. Replaced waters are warmer than they were before causing DO ↓

Cooling towers can be build to cool the water before they are discharged back into the water body.

• Excessive amounts of suspended solids in water.

• Come from soil erosion• Increases turbidity which reduces the

amount of sunlight that penetrates the water →

• ↓ photosynthesis → ↓ DO

• Carries toxic pollutants, disease-causing agents

• Filling in waterways (reduces depth)• Slows water flow → ↓DO• Disrupts food chain• Clogs gills• a turbidity test is performed to determine

the amount of suspended solids in water

• pH• plant nutrients• heavy metals• radioactive substances

• 3.0 – 3.5 = toxic to most life• 3.5 – 4.0 = lethal to trout and other fish• 4.0 – 4.5 = fish eggs; dead lake• 5.0 – 6.0 = changes ecology (biodiversity,

#, decline is fish species, high aluminum, slow decomposition, nutrients trapped at bottom, algae disappears, crystal clear,

• 6.5 – 9.0 mostly harmless• 9.0+ harmful to lethal as pH goes up to

11.5

• Nitrites/nitrates; phosphorous– increases plant growth; – sources: fertilizers, sewage– causes algal bloom; eutrophication

• ↑ plant life → blocks sunlight → ↓ photosynthesis → plants die → ↑BOD → ↓DO → fish kill

– cultural eutrophication = same as above caused by human sewage

• Sources– leaching of soil due to acid rain, burning coal,

industrial, household and mining wastes.• Health Concerns

– damages nervous system, kidneys, vision, Minimata• 1932 – 1968 – Co dumped 27 tons mercury

compounds into Minimata Bay – Hg converted to methyl mercury – ingested by eating fish – 43 people died

• Sources:– paint, mining, incinerator ash, lead pipes and

solder (contaminate water), auto exhaust• Health Concerns

– damage to kidneys, nervous system (brain), ability to learn, depressed biosynthesis of proteins, nerves, red blood cells; anemia, irritability

• Sources:– electroplating, mining, plastic industries,

sewage• Health Concerns

– kidney disease

• Sources:– herbicides, wood preservatives, mining industry

• Health Concerns– Damage to eyes, skin, GI tract, liver; cancer

• Sources:– leaching due to acid rain

• Health Concerns– anemia, loss of bone strength; possible role in

dementia, and Alzheimer’s

• oceans become contaminated by nuclear waste from illegal dumping, bomb tests, and nuclear accidents