Water PollutionWater Pollution

Point Source Pollution

vs. Nonpoint Source

Pollution

What’s the difference?

Point and Nonpoint SourcesPoint and Nonpoint Sources

NONPOINT SOURCES

Urban streets

Suburban development

Wastewater treatment plant

Rural homes

Cropland

Factory

Animal feedlot

POINT SOURCES

Point Source Pollution

comes from a specific source, like a pipe

factories, industry, municipal treatment plants

can be monitored and controlled by a permit system

What is nonpoint source pollution?

Nonpoint Source (NPS) Pollution is pollution associated with stormwater or runoff

NPS pollution cannot be traced to a direct discharge point such as a wastewater treatment facility

Examples of NPS

oil & grease from cars

fertilizers animal waste grass clippings septic systems

sewage & cleaners from boats

household cleaning products

litter

Pollutant Transport Mechanisms

• NPS pollutants build up on land surfaces during dry weather

Atmospheric depositionFertilizer applicationsAnimal wasteAutomotive exhaust/fluid leaks

• Pollutants are washed off land surfaces during precipitation events (stormwater runoff)

• Stormwater runoff will flow to lakes and streams

Linking Land Use to Water Quality

More Coverings= More Water

What do we mean by cover?

roads, rooftops, parking lots, and other hard surfaces that do not allow stormwater to soak into the ground

“predominant American vegetation”

Cover

• provides a surface for accumulation of pollutants

• leads to increased polluted runoff and flooding

• inhibits recharge of groundwater

Impact of Nonpoint Source Pollution

fish and wildlife recreational

water activities commercial

fishing tourism drinking water

quality

Pollutants Found in RunoffSediment

Soil particles transported from their source

Biochemical Oxygen Demand (BOD) ● Oxygen depleting materialLeavesOrganic material

Toxics● Pesticides Herbicides Fungicides Insecticides

● Metals (naturally occurring in soil, automotive emissions/ tires) Lead Zinc Mercury

● Petroleum Hydrocarbons (automotive exhaust and fuel/oil)DebrisLitter and illegal dumping

Nutrients● Various types of materials that become dissolved and suspended in water (commonly found in fertilizer and plant material): Nitrogen (N) Phosphorus (P)

Bacteria/ PathogensOriginating from:● Pets● Waterfowl● Failing septic systems

Thermal StressHeated runoff, removal of streamside vegetation

Potential Sources of Pollutants Found in Residential Areas

Nutrients: Fertilizers and septic systems

Pathogens: Pet waste and septic systems

Sediment: Construction, road sand, soil erosion

Toxic: Pesticides, household products

Debris: Litter and illegal dumping

Thermal: heated runoff, removal of streamside vegetation

Pollutants from AgriculturePollutants from Agriculture

• Sediment

• Nutrients

• Pathogens

• Pesticides

Why are these pollutants important?

Sediment reduces light penetration in stream, clogs gills of fish and aquatic invertebrates.

Nutrients act as fertilizer for algae & aquatic plants which can cause highly varying dissolved oxygen levels. At low DO levels, the aquatic life has the potential to be harmed.

Toxics can impact life and contaminate drinking water supplies.

Bacteria/Pathogens are an indicator of possible viruses present in the system.

Rainbow smelt1.04 ppm

Zooplankton0.123 ppm

Phytoplankton0.0025 ppm

Water0.000002 ppm

Herring gull124 ppm

Lake trout4.83 ppm

Herring gull eggs124 ppm

Biological Magnification

Biological Magnification

Pollution of StreamsPollution of Streams

Oxygen sag curveOxygen sag curve Oxygen sag curveOxygen sag curve

Fig. 20-5

MississippiRiver Basin

MissouriRiver

OhioRiver

MississippiRiver

LOUISIANAMississippi

River

Depleted

Oxygen

Gulf of Mexico

Pollution of LakesPollution of Lakes Eutrophication Eutrophication

Groundwater Pollution: CausesGroundwater Pollution: Causes

Low flow rates Low flow rates Few bacteria Few bacteria Cold temperatures Cold temperatures

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

Unconfined freshwater aquifer

Confined freshwater aquifer

Water pumping well Landfill

Low oxygen Low oxygen

Solutions: Preventing and Reducing Surface Water PollutionSolutions: Preventing and Reducing Surface Water Pollution

Nonpoint SourcesNonpoint Sources Point SourcesPoint Sources

Reduce runoffReduce runoff

Buffer zone vegetation

Buffer zone vegetation

Reduce soil erosionReduce soil erosion

Clean Water ActClean Water Act

Water Quality ActWater Quality Act

Groundwater Pollution PreventionGroundwater Pollution Prevention

Monitor aquifers Monitor aquifers

Leak detection systems Leak detection systems

Strictly regulating hazardous waste disposal Strictly regulating hazardous waste disposal

Store hazardous materials above ground Store hazardous materials above ground

Find less hazardous substitutes Find less hazardous substitutes

Case Study: Chesapeake BayCase Study: Chesapeake Bay

Largest US estuary

Largest US estuary

Relatively shallow Relatively shallow

Slow “flushing” action to Atlantic

Slow “flushing” action to Atlantic

Major problems with dissolved O2 Major problems with dissolved O2

Ocean PollutionOcean Pollution

Prevention Cleanup

Ban dumping of wastes and sewage by maritime and cruise ships in coastal waters

Reduce input of toxic pollutants

Separate sewage and storm lines

Regulate coastal development

Recycle used oil

Require double hulls for oil tankers

Require at least secondary treatment of coastal sewage

Use wetlands, solar-aquatic, orother methods to treat sewage

Sprinkle nanoparticles over an oil or sewage spill to dissolve the oil or sewage without creating harmful byproducts(still under development)

Protect sensitive areas from development, oil drilling, and oil shipping

Ban ocean dumping of sludge and hazardous dredged material

Improve oil-spill cleanup capabilities

SolutionsCoastal Water Pollution

Technological Approach: Septic SystemsTechnological Approach: Septic Systems

Require suitable soils and maintenanceRequire suitable soils and maintenance

Sewage TreatmentSewage Treatment

Physical and biological treatmentPhysical and biological treatmentFig. 22-16 p. 511

Technological Approach: Using Wetlands to Treat SewageTechnological Approach: Using Wetlands to Treat Sewage

Fig. 22-18 p. 513

Solutions

Water Pollution

•Prevent groundwater contamination

•Greatly reduce nonpoint runoff

•Reuse treated wastewater for irrigation

•Find substitutes for toxic pollutants

•Work with nature to treat sewage

•Practice four R's of resource use (refuse,

reduce, recycle, reuse)

•Reduce resource waste

•Reduce air pollution

•Reduce poverty

•Reduce birth rates

WetlandsWetlands

Home to ~33% of nation’s threatened and Home to ~33% of nation’s threatened and endangered speciesendangered species

Statistics— 50% loss since 1900 in US; cities Statistics— 50% loss since 1900 in US; cities on filled wetlands; rising sea levelon filled wetlands; rising sea level

Mitigation banking—Nat’l Academy: ~half of Mitigation banking—Nat’l Academy: ~half of attempts to build a wetland fail.attempts to build a wetland fail.

More than 500 wetland restoration banks in More than 500 wetland restoration banks in USUS

Virtues of WetlandsVirtues of Wetlands

• Home to wildlife and floraHome to wildlife and flora

• Flood protectionFlood protection

• Cycling and storage of chemical Cycling and storage of chemical and biological substancesand biological substances

• Found at heads of riversFound at heads of rivers

• Remove toxins from sewageRemove toxins from sewage

How Wetlands are DestroyedHow Wetlands are Destroyed

• Mostly by draining for development Mostly by draining for development or farming.or farming.

• To ‘reclaim’ land along coastlinesTo ‘reclaim’ land along coastlines

The EvergladesThe Everglades• ~77,000 sq km; 3 sub-basins~77,000 sq km; 3 sub-basins• Thin sheet of water 40-60 miles wideThin sheet of water 40-60 miles wide• Formed ~5000 yrs ago--howFormed ~5000 yrs ago--how• Human influences: Human influences:

late 1880’s—first dredginglate 1880’s—first dredging1907 and 1928: canals—saltwater; draining south of Lake O. 1907 and 1928: canals—saltwater; draining south of Lake O. 1961-1971: Kissimee River channelized1961-1971: Kissimee River channelized

• 65% now drained65% now drained• Plants and animals depend on water level timing—seriously Plants and animals depend on water level timing—seriously

disturbeddisturbed• Number of species of wading birds—dropped 95% since Number of species of wading birds—dropped 95% since

19471947

Protecting, Sustaining, and Restoring WetlandsProtecting, Sustaining, and Restoring Wetlands

Regulations Regulations

Mitigation bankingMitigation banking

Wetlands protectionWetlands protection

Wetlands restorationWetlands restoration

Control of invasive species

Control of invasive species

Supply of Water ResourcesSupply of Water Resources

FreshwaterFreshwater Readily accessible freshwaterReadily accessible freshwater

Biota0.0001%

Biota0.0001%

Rivers0.0001%Rivers

0.0001%

Atmosphericwater vapor

0.0001%

Atmosphericwater vapor

0.0001%

Lakes0.0007%

Soilmoisture0.0005%

Groundwater0.592%

Groundwater0.592%

Ice capsand glaciers

0.592%

0.014%0.014%

Use of Water ResourcesUse of Water Resources

Humans use about 54% of reliable runoff Humans use about 54% of reliable runoff

Agriculture Agriculture

Industry Industry

Domestic Domestic

Power plants Power plants

United States

Industry 11%

Public 10%

Powercooling

38%

Agriculture38%

Evaporation and transpiration

Evaporation

Stream

Infiltration

Water tableInfiltration

Unconfined aquifer

Confined aquifer

Lake

Well requiring a pump

Flowingartesian well

Runoff

Precipitation

ConfinedRecharge Area

Aquifer

Less permeable materialsuch as clay Confirming permeable rock layer

Ground WaterGround Water

Problems with Using GroundwaterProblems with Using Groundwater

Water table loweringWater table lowering

DepletionDepletion

SubsidenceSubsidence

Saltwater intrusionSaltwater intrusion

Chemical contaminationChemical contamination

Reduced stream flowsReduced stream flows

Groundwater Pollution: CausesGroundwater 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

Unconfined freshwater aquifer

Confined freshwater aquifer

Water pumping well Landfill

Fig. 20-11

Fig. 20-12

Aquifer

Water well

Migrating vapor phase

Contaminant plume moveswith the groundwater

Free gasolinedissolves ingroundwater(dissolved phase)

Groundwaterflow

Watertable

Gasolineleakage plume(liquid phase)

Leakingtank

Bedrock

Too Little WaterToo Little Water

Dry climateDry climate

Drought Drought

DesiccationDesiccation

Water stressWater stress

Acute shortage

Adequate supply

Shortage

Metropolitan regions with population greater than 1 million

$23 billion/year for 8-10 years to bring clean drinking water to those who don’t have it

$23 billion/year for 8-10 years to bring clean drinking water to those who don’t have it

• Consequences of a warmer world

• Pollution of freshwater streams

• Dilution and biodegradatoin

• Breakdown of pollutants by bacteria—oxygen sag curve

Developing countries: half of Developing countries: half of world’s 500 major rivers are world’s 500 major rivers are heavily pollutedheavily polluted

Global Outlook: Stream Pollution in Developing CountriesGlobal 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 20-7Figure 20-7

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

Is Bottled Water the Answer?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 WaterUsing 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.