Every time water completes its cycle from vapor to liquid or solid and back to vapor again, its quality is renewed. However, water quality can be damaged by any number of pollutants in the air, on land, or from other water supplies. The Water Quality Primer introduced you why water quality is important.  The amount of water available for use depends on its quality, and the availability of water dictates where we can live, build cities, and create industry.

On the average, every American uses about 150 gallons of water a day. It’s no wonder that in some highly populated areas, water supplies are getting tight.

Human activities change the quality of our lakes and streams.  Each time we use water, we change its quality by adding substances to it. These materials are such things as municipal sewage, toxic chemicals, solvents, automotive oils, fertilizers, detergents, pesticides, soil, and even extra heat. Some materials, even in small quantities, can damage water quality to the point to make it unusable. A single quart of motor oil, for example, could pollute as much as 250,000 gallons of water.

Our 120,000-acre Aux Sable Creek watershed is home to 14,500 people based on 2000 Census data.  This is more than double the 1990 estimates of just over 5,600 residents.  In 2009, agriculture remains the dominant land use.  However, that is changing.  Since the late 1990s, development has occurred primarily in the southern and eastern edges of the watershed.  There are now residential subdivisions and industrial developments in the watershed.  Nonpoint source pollution is the largest issue in such areas.  Nonpoint source pollution occurs when runoff from rain and snowmelt carries pollutants into waterways such as rivers, streams, lakes, wetlands, and even groundwater.  Click here for more information on nonpoint source pollution

Key areas of concern for the Aux Sable Creek Watershed, when it comes to nonpoint source pollution, are stormwater and erosion and sediment.  In addition, the Illinois Environmental Protection Agency has identified a use impairment in the Aux Sable Creek.  In 2004, a stretch was designated as not meeting the Primary Contact Use Support (e.g. swimming).  Prior to 2004, no use impairments had been identified.  The potential cause: fecal coliform bacteria.  The presence of fecal coliform bacteria in aquatic environments may indicate that the water has been contaminated with the fecal material of people or animals. Often, fecal coliform bacteria can enter rivers through direct discharge of waste from mammals and birds, from agricultural and storm runoff, and from untreated human sewage. The good news is we can work together to minimize and address these negative impacts, thus preserving and maintaining the Aux Sable Creek’s high water quality for everyone to enjoy.  The watershed plan worked to identify potential sources of these negative impacts so that watershed stakeholders have a better understanding of priority focus areas.  Following is some information about these key areas of concern.




Fecal Coliform

Wrong Picture

“What’s Wrong with this Picture?” 

Click here to visit EPA’s website to

learn more about nonpoint source