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Water Sense
Urban Water Sustainability Council
Untitled Document


>>WATER >>> THE EARTH'S WATER SUPPLY

Although 75% of the Earth is covered with water, very little is available for us to use. 97.2% of the Earth's water supply is salt water.  Only 2.8% is freshwater!

Freshwater (the water we can use) is found on earth in the following sources:
  • 0.001% is water vapor 
  • 0.6% is groundwater
  • 0.01% is in lakes and streams
  • 2.2% is in glaciers and icecaps

We can only use some of the groundwater (.6%) and the water that's found in rivers, lakes and streams (.01%). Together, that's less than 1%!  This means that we must use the water we have wisely.  Over 6 billion people in the world are counting on it!


 How Does Water Get Polluted?
Everything we do affects our water.  Whether we throw litter and garbage on the ground, pour things that we shouldn't down storm drains, or simply leave pet waste on the ground; it all ends up traveling through storm drains that lead directly to our creeks, streams, rivers, lakes and oceans.  This major source of pollution is called polluted stormwater runoff. 

Water pollution comes from other sources too. Sewer overflows add pollution when the sewer system and wastewater treat plants get too full during heavy rain fall. Industry sometimes pollutes water by releasing harmful substances into the water or the air.  Even pouring harmful substances down sinks at home, or flushing old medicine down the toilet can increase pollution because the wastewater treatment process is not designed to remove a lot of these harmful substances.

We've got to work really hard to keep these and other pollution sources out of our water supply! Click here to find out things we can do to protect water from pollution. 

Recycling helps to reduce the amount of pollution that gets into our water.  Disposing of hazardous materials in a safe, environmentally friendly way.  MMSD funds the operation of three year-round facilities that collect harmful substances that would otherwise be thrown into our garbage, our waterways, or taken to landfills.  Download this form to find out what kinds of things to take to these recycling facilities.
  Did you know that old computers, cell phones, and televisions have radioactive materials inside of them?  Throwing them away outside, along a waterway, or into the garbage increases the possibility of harmful substances getting into our water.  Below is a list of disposal sites in the state of Wisconsin.