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

The Hydrological cycle

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

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

Confined and Unconfined Aquifers

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one third of all groundwater to the U.S. Holds enough water to cover the U.S. to a depth of 1.5ft Water is being withdrawn 10 to 40 times the rate of replacement

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.

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

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

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.

Point Source or Non Point-Source?

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

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

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

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

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

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

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

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

Cuyahoga River fire - 1969 This river in Cleveland, Ohio was so polluted with petroleum products that it caught fire!

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

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

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

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

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

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

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.