1. What you will learn… Water resources Water pollution
Wastewater treatment
Water quality in Iowa
Global water shortage

2. The Hydrological cycle

4. Surface water and Ground water
Water beneath the Earth’s surface in sediment and rock formations.
Where rock and soil is saturated with water, this level is called the water table
Surface Water -
Fresh water on Earth’s land surface.
Lakes, rivers, streams and wetlands
Most large cities depend on surface water for their water supply

5. What is an Aquifer?
An aquifer is an underground formation containing groundwater.
Most aquifers are made of rock, sand or gravel with lots of spaces where water can accumulate
An area of the Earth’s surface from which water percolates into an aquifer is called the Recharge zone.
Structures on a recharge zone can affect how long it takes to recharge an aquifer

6. Confined and Unconfined Aquifers

7. Ogallala Aquifer World’s largest Aquifer
Supplies one third of all groundwater to the U.S.
Holds enough water to cover the U.S. to a depth of 1.5ft
Water is being withdrawn 10 to 40 times the rate of replacement

8. What is a watershed?
A watershed is the region or area of land that drains into a body of water such as a lake, river or stream.
The Mississippi watershed
covers 40 % of the U.S.

9. Water Pollution:
The introduction of chemical, physical or biological agents into the water that degrade water quality.
2 main causes of water pollution are:
Industrialization
Rapid human population growth

10. Point-Source Pollution
Pollution discharged from a single source. Ex. Leaking oil tanker, factory wastewater pipe.

11. Non Point-Source Pollution:
Pollution which comes from many sources that may be difficult to identify. Ex. Runoff from crop fields, chemicals added to road surfaces.

12. Point Source or Non Point-Source?

14. Artificial Eutrophication
Fertilizer runoff, sewage, and detergents containing phosphates cause algae to grow out of control
As the algae die, bacteria that break them down use all the oxygen in the water
Fish and other life suffocate
Dead Zone in Gulf of Mexico
reaches 6,000 – 7,000 sq.miles

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

16. Groundwater Pollution
Leaking underground storage tanks are a source of groundwater pollution
DNR estimates there are 100,000 failing septic tank systems in Iowa
19 million gallons of untreated wastewater empties into Iowa rivers each day from failing septic tanks

17. Arsenic in Bangladesh groundwater
1970’s UNICEF campaign to provide groundwater wells for Bangladesh
1990’s scientists discovered wells contaminated with Arsenic
57 million people were affected
Arsenic is of natural origin
Possible overuse for irrigation increased arsenic concentrations
>10µg/ml can cause skin disorders
and cancer

18. Thermal Pollution
When the temperature of a water body changes, thermal pollution may occur
As water temperature rises, the amount of oxygen water can hold decreases
Power plants use water in their
cooling systems

19. Wastewater Treatment
Primary treatment: physical removal in settling tanks
Secondary treatment: aerobic bacteria degrade waste
Treated with chlorine and pumped into river
Solid material (sludge) is sent to digesting vats where microorganisms aid decomposition
Biosolids sent to landfill or applied to agricultural land
Methane gas is used to generate electricity

21. Ocean Pollution 85% of ocean pollution comes from activities on land
Cruise ships can dump untreated waste into the ocean once they are 3 miles from land
The U.N. Environment Programme (UNEP) estimates that 46,000 pieces of plastic litter are floating on every square mile of the oceans

22. Oil Spills
Oil Spills – account for only 5% of oil pollution in oceans.
Most oil pollution comes from nonpoint-sources on land

23. Cuyahoga River fire
This river in Cleveland, Ohio was so polluted with petroleum products that it caught fire!

24. Water pollution in Iowa
Iowa in 1970
Waterways were running red with waste from slaughtering plants
Communities were sending untreated sewage into rivers
High nitrate levels plagued drinking water

25. 1972 – Clean Water Act
“To restore and maintain the chemical, physical, and biological integrity of the nation’s waters.”
It’s goal was to make all surface waters safe for swimming and fishing by 1983.
It has failed to achieve this but some progress has been made.
In 2004, 209 of Iowa’s waterways were considered impaired

26. What are the main sources of water pollution in Iowa?
Runoff from agricultural land adds sediment, nutrients and pesticides
Manure spills add ammonia and bacteria
Runoff from construction sites, lawns and streets
Leaking septic tank systems

27. Sediment In Iowa, the #1 water quality concern is soil erosion
Erosion carries fine particles (sediment) to our streams
When sediment settles on stream bottoms it smothers plants and animals
Sediment suspended in water prevents light reaching plants in the water
Sediment makes rivers shallower and slower. Such rivers have less dissolved oxygen
Bacteria often attach to sediment

28. Nutrients
Nitrogen and Phosphorus are necessary nutrients for growing crops
In our water they contribute to overproduction of algae
Artificial eutrophication results

29. Biological Oxygen Demand and Dissolved Oxygen
(BOD) is a measure of the oxygen used by microorganisms to decompose waste.
(DO) is the amount of Oxygen dissolved in the water
Where there is a lot of waste: Nitrates, phosphate, sewage) in the water BOD is high and dissolved oxygen is low
As waste is consumed or dispersed BOD declines, DO increases

30. Pollution is not our only Problem…

31. Global Water Shortage

32. 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

33. 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.