Water Pollution

Types of Water Pollution

Point sources

Nonpoint sources

Biological oxygen demand

Water quality

Water

Quality

Good 8-9

Do (ppm) at 20˚C

Slightly

polluted

Moderately

polluted

Heavily

polluted

Gravely

polluted

6.7-8

4.5-6.7

Below 4.5

Below 4

Point and Nonpoint Sources

NONPOINT SOURCES

Urban streets

Suburban development

Wastewater treatment plant

Rural homes

Cropland

Factory

Animal feedlot

POINT SOURCES

Water pollution Sources

Bacteria,Viruses,Protozoa, Parasitic worms

Oxygen demanding substances

Inorganic plant nutrients

Organic chemicals

Sediment or suspended matter

Thermal pollution

Genetic pollution

Rainbow smelt 1.04 ppm

Zooplankton 0.123 ppm

Phytoplankton 0.0025 ppm

Water 0.000002 ppm

Herring gull 124 ppm

Lake trout 4.83 ppm

Herring gull eggs 124 ppm

Biological

Magnification

Pollution of Streams

Oxygen Sag curve

Pollution of Lakes

Discharge of untreated municipal sewage

(nitrates and phosphates)

Nitrogen compounds produced by cars

and factories

Discharge of treated municipal sewage

(primary and secondary treatment:

nitrates and phosphates)

Discharge of detergents

( phosphates)

Natural runoff (nitrates and phosphates

Manure runoff From feedlots (nitrates and Phosphates,

ammonia)

Dissolving of nitrogen oxides

(from internal combustion engines and furnaces)

Runoff and erosion (from from cultivation, mining, construction,

and poor land use)

Runoff from streets, lawns, and construction

lots (nitrates and phosphates)

Lake ecosystem nutrient overload

and breakdown of chemical cycling

Fig .22.7, p. 499

(Eutrophication diagram )

Groundwater Pollution: Causes

Coal strip mine runoff

Pumping well

Waste lagoon

Accidental spills

Groundwater flow

Confined aquifer

Discharge

Leakage from faulty casing

Hazardous waste injection well

Pesticides

Gasoline station

Buried gasoline and solvent tank

Sewer

Cesspool septic tank

De-icing road salt

Water pumping well Landfill

Water well

Migrating vapor phase

Contaminant plume moves with the groundwater

Free gasoline dissolves in groundwater (dissolved phase)

Groundwater flow

Water table

Gasoline leakage plume (liquid phase)

Leaking tank

Global Outlook: Stream Pollution in Developing Countries

Water in many of central China's rivers are greenish black from uncontrolled pollution by thousands of factories.

Figure 20-7

Case Study: India’s Ganges River: Religion, Poverty, and Health

Religious beliefs, cultural traditions, poverty, and a large population interact to cause severe pollution of the Ganges River in India.

Very little of the sewage is treated.

Hindu believe in cremating the dead to free the soul and throwing the ashes in the holy Ganges.

Some are too poor to afford the wood to fully cremate.

Decomposing bodies promote disease and depletes DO.

Case Study: India’s Ganges River: Religion, Poverty, and Health

Daily, more than 1 million Hindus in India bathe, drink from, or carry out religious ceremonies in the highly polluted Ganges River.

Water Pollution Prevention

Monitoring aquifers

Strictly regulating hazardous waste

disposal

Storing hazardous materials above

ground

Reducing Water Pollution through Sewage Treatment

Primary and Secondary sewage treatment.

Technological Approach: Using Wetlands to Treat Sewage

(

(

45 centimeter

layer of limestone

gravel coated with

decomposing bacteria First concrete pool Second concrete pool

Sewage

Wetland type

plants

Wetland type

plants

Treated

water

Drinking Water Quality

Safe Drinking Water Act

Maximum contaminant levels

Bottled water

Is Bottled Water the Answer?

Some bottled water is not as pure as tap water and costs much more.

1.4 million metric tons of plastic bottles are thrown away.

Fossil fuels are used to make plastic bottles.

The oil used to produce plastic bottles in the U.S. each year would fuel 100,000 cars.

Using Laws to Protect Drinking Water

The U.N. estimates that 5.6 million Americans drink water that does not meet EPA standards.

1 in 5 Americans drinks water from a treatment plant that violated one or more safety standard.

What Can You Do?

Water Pollution

• Fertilize garden and yard plants with manure or compost

instead of commercial inorganic fertilizer.

• Minimize your use of pesticides.

• Do not apply fertilizer or pesticides near a body of water.

• Grow or buy organic foods.

• Do not drink bottled water unless tests show that your tap

water is contaminated. Merely refill and reuse plastic bottles

with tap water.

• Compost your food wastes.

• Do not use water fresheners in toilets.

• Do not flush unwanted medicines down the toilet.

• Do not pour pesticides, paints, solvents, oil, antifreeze, or other

products containing harmful chemicals down the drain or

onto the ground.

Roger Rosenblatt

It is a hard truth to swallow, but nature does not care if we live or die. We cannot survive without the oceans, for example, but they can do just fine without us.