What you will learn…

•Water resources

•Water pollution

•Wastewater treatment

•Water quality in Iowa

•Global water shortage

The Hydrological cycleThe Hydrological cycle

Surface water and Ground Surface water and Ground waterwater• Surface Water -Surface Water -

Fresh water on Fresh water on Earth’s land Earth’s land surface.surface.

Lakes, rivers, Lakes, rivers, streams and streams and wetlandswetlands

Most large cities Most large cities depend on surface depend on surface water for their water for their water supplywater supply

• Ground Water -Ground Water -

Water beneath the Water beneath the Earth’s surface in Earth’s surface in sediment and rock sediment and rock formations.formations.

Where rock and soil Where rock and soil is saturated with is saturated with water, this level is water, this level is called the water called the water tabletable

What is an Aquifer?What is an Aquifer?

• An aquifer is an underground An aquifer is an underground formation containing groundwater.formation containing groundwater.

• Most aquifers are made of rock, sand Most aquifers are made of rock, sand or gravel with lots of spaces where or gravel with lots of spaces where water can accumulatewater can accumulate

• An area of the Earth’s surface from An area of the Earth’s surface from which water percolates into an aquifer which water percolates into an aquifer is called the is called the Recharge zone.Recharge zone.

• Structures on a recharge zone can Structures on a recharge zone can affect how long it takes to recharge an affect how long it takes to recharge an aquiferaquifer

Confined and Unconfined Aquifers

Ogallala AquiferOgallala Aquifer

• World’s largest AquiferWorld’s largest Aquifer

• Supplies one third of all Supplies one third of all groundwater to the U.S.groundwater to the U.S.

• Holds enough water to Holds enough water to cover the U.S. to a cover the U.S. to a depth of 1.5ftdepth of 1.5ft

• Water is being Water is being withdrawn 10 to 40 withdrawn 10 to 40 times the rate of times the rate of replacementreplacement

What is a watershed?What is a watershed?• A watershed is the region or area of A watershed is the region or area of

land that drains into a body of water land that drains into a body of water such as a lake, river or stream.such as a lake, river or stream.

• The Mississippi watershedThe Mississippi watershed

covers 40 % of the U.S.covers 40 % of the U.S.

Water Pollution:Water Pollution:

• The introduction of chemical, The introduction of chemical, physical or biological agents into the physical or biological agents into the water that degrade water quality.water that degrade water quality.

2 main causes of water pollution are:2 main causes of water pollution are:

1.1. IndustrializationIndustrialization

2.2. Rapid human population growthRapid human population growth

Point-Source PollutionPoint-Source Pollution

• Pollution Pollution discharged from a discharged from a single source. Ex. single source. Ex. Leaking oil tanker, Leaking oil tanker, factory wastewater factory wastewater pipe.pipe.

Non Point-Source Pollution:Non Point-Source Pollution:

• Pollution which comes from many Pollution which comes from many sources that may be difficult to sources that may be difficult to identify. Ex. Runoff from crop fields, identify. Ex. Runoff from crop fields, chemicals added to road surfaces.chemicals added to road surfaces.

Point Source or Non Point-Source?

Artificial EutrophicationArtificial Eutrophication• Fertilizer runoff, Fertilizer runoff,

sewage, and sewage, and detergents containing detergents containing phosphates cause phosphates cause algae to grow out of algae to grow out of controlcontrol

• As the algae die, As the algae die, bacteria that break bacteria that break them down use all them down use all the oxygen in the the oxygen in the waterwater

• Fish and other life Fish and other life suffocatesuffocate Dead Zone in Gulf of Mexico

reaches 6,000 – 7,000 sq.miles

Fish Kill Bayou Chaland area of Plaquemines Parish Sept 10th 2010

Groundwater PollutionGroundwater Pollution

• Leaking underground Leaking underground storage tanks are a storage tanks are a source of groundwater source of groundwater pollutionpollution

• DNR estimates there DNR estimates there are 100,000 failing are 100,000 failing septic tank systems in septic tank systems in IowaIowa

• 19 million gallons of 19 million gallons of untreated wastewater untreated wastewater empties into Iowa empties into Iowa rivers each day from rivers each day from failing septic tanksfailing septic tanks

Arsenic in Bangladesh Arsenic in Bangladesh groundwatergroundwater

• 1970’s UNICEF campaign to 1970’s UNICEF campaign to provide groundwater wells for provide groundwater wells for BangladeshBangladesh

• 1990’s scientists discovered 1990’s scientists discovered wells contaminated with wells contaminated with ArsenicArsenic

• 57 million people were 57 million people were affectedaffected

• Arsenic is of natural originArsenic is of natural origin

• Possible overuse for irrigation Possible overuse for irrigation increased arsenic increased arsenic concentrationsconcentrations

>10µg/ml can cause skin disorders and cancer

Thermal PollutionThermal Pollution

• When the When the temperature of a temperature of a water body changes, water body changes, thermal pollution thermal pollution may occurmay occur

• As water As water temperature rises, temperature rises, the amount of the amount of oxygen water can oxygen water can hold decreaseshold decreases

Power plants use water in their cooling systems

WASTEWATER WASTEWATER TREATMENTTREATMENT

• PrimaryPrimary treatment: physical removal in settling treatment: physical removal in settling tankstanks

• SecondarySecondary treatment: aerobic bacteria treatment: aerobic bacteria degrade wastedegrade waste

• Treated with chlorine and pumped into riverTreated with chlorine and pumped into river

• Solid material (sludge) is sent to digesting vats Solid material (sludge) is sent to digesting vats where microorganisms aid decompositionwhere microorganisms aid decomposition

• Biosolids sent to landfill or applied to Biosolids sent to landfill or applied to agricultural landagricultural land

• Methane gas is used to generate electricityMethane gas is used to generate electricity

Ocean PollutionOcean Pollution

• 85% of ocean pollution comes from 85% of ocean pollution comes from activities on landactivities on land

• Cruise ships can dump untreated waste Cruise ships can dump untreated waste into the ocean once they are 3 miles from into the ocean once they are 3 miles from landland

• The U.N. Environment Programme (UNEP) The U.N. Environment Programme (UNEP) estimates that 46,000 pieces of plastic estimates that 46,000 pieces of plastic litter are floating on every square mile of litter are floating on every square mile of the oceansthe oceans

Oil SpillsOil Spills

• Oil Spills – account Oil Spills – account for only 5% of oil for only 5% of oil pollution in oceans.pollution in oceans.

• Most oil pollution Most oil pollution comes from comes from nonpoint-sources nonpoint-sources on landon land

Cuyahoga River fire - 1969Cuyahoga River fire - 1969• This river in Cleveland, Ohio was so This river in Cleveland, Ohio was so

polluted with petroleum products that it polluted with petroleum products that it caught fire!caught fire!

Water pollution in IowaWater pollution in IowaIowa in 1970Iowa in 1970- Waterways were Waterways were

running red with running red with waste from waste from slaughtering plantsslaughtering plants

- Communities were Communities were sending untreated sending untreated sewage into rivers sewage into rivers

- High nitrate levels High nitrate levels plagued drinking plagued drinking waterwater

1972 – Clean Water Act1972 – Clean Water Act

““To restore and maintain the chemical, To restore and maintain the chemical, physical, and biological integrity of the physical, and biological integrity of the nation’s waters.”nation’s waters.”

It’s goal was to make all surface waters It’s goal was to make all surface waters safe for swimming and fishing by safe for swimming and fishing by 1983.1983.

It has failed to achieve this but some It has failed to achieve this but some progress has been made.progress has been made.

In 2004, In 2004, 209209 of Iowa’s waterways were of Iowa’s waterways were considered impairedconsidered impaired

What are the main sources of What are the main sources of water pollution in Iowa?water pollution in Iowa?

• Runoff from agricultural land adds Runoff from agricultural land adds sediment, nutrients and pesticidessediment, nutrients and pesticides

• Manure spills add ammonia and Manure spills add ammonia and bacteria bacteria

• Runoff from construction sites, lawns Runoff from construction sites, lawns and streetsand streets

• Leaking septic tank systemsLeaking septic tank systems

SedimentSediment• In Iowa, the #1 water quality In Iowa, the #1 water quality

concern is soil erosionconcern is soil erosion• Erosion carries fine particles Erosion carries fine particles

(sediment) to our streams(sediment) to our streams• When sediment settles on When sediment settles on

stream bottoms it smothers stream bottoms it smothers plants and animalsplants and animals

• Sediment suspended in water Sediment suspended in water prevents light reaching plants prevents light reaching plants in the waterin the water

• Sediment makes rivers Sediment makes rivers shallower and slower. Such shallower and slower. Such rivers have less dissolved rivers have less dissolved oxygenoxygen

• Bacteria often attach to Bacteria often attach to sedimentsediment

NutrientsNutrients

• Nitrogen and Nitrogen and Phosphorus are Phosphorus are necessary nutrients necessary nutrients for growing cropsfor growing crops

• In our water they In our water they contribute to contribute to overproduction of overproduction of algaealgae

• Artificial Artificial eutrophication resultseutrophication results

Biological Oxygen Demand and Biological Oxygen Demand and Dissolved OxygenDissolved Oxygen

• (BOD) is a measure of the oxygen used by (BOD) is a measure of the oxygen used by microorganisms to decompose waste.microorganisms to decompose waste.

• (DO) is the amount of Oxygen dissolved in the water (DO) is the amount of Oxygen dissolved in the water

• Where there is a lot of waste: Nitrates, phosphate, Where there is a lot of waste: Nitrates, phosphate, sewage) in the water BOD is high and dissolved sewage) in the water BOD is high and dissolved oxygen is lowoxygen is low

• As waste is consumed or dispersed BOD declines, DO As waste is consumed or dispersed BOD declines, DO increasesincreases

Pollution is not our only Problem…

Global Water Shortage

Global Water Crisis - Basic Facts

•Less than 1% of the world’s fresh water (or about 0.007% of all water on earth) is readily accessible for direct human use.

•The average American individual uses 100 to 176 gallons of water each day.

•The average African family uses about 5 gallons of water each day

Global Water Crisis – Basic facts•Every 15 seconds, a child dies from a

water-related disease.

•At any given time, half of the world’s hospital beds are occupied by patients suffering from a water-related disease.

•1.8 million children die each year from diarrhea – 4,900 deaths each day.