We've probably all seen it - green scum, water that looks like pea soup, a funky smell to a usually clear and beautiful lake.

Excessive amounts of algae can turn our blue lakes green with algae and ruin many of Minnesota's prime fishing spots and swimming holes.

Photograph Compliments of:
© Seattle Department of Natural Resources
 

Farmers and livestock operators tend to receive the bulk of the blame for dirtying Minnesota's lakes and rivers.  According to the Federal Environmental Protection Agency, agricultural fertilizer, herbicides, pesticides, and livestock waste are major contributors to water pollution.

Yet what's less known is that city folk do their share of mucking up lakes and rivers too.  The biggest problem is the buildup of organic materials such as leaves and grass clippings, which moves from lawns to streets to gutter, and eventually flush untreated into lakes and rivers.

As they decay, grass and leaves release phosphorous, which increases algae growth.  When algae populations explode, they form a scum that blocks the sunlight from reaching plants.  When the algae die and decay, they use up oxygen needed by fish and other aquatic life.

Organic material from yards is the number one pollutant in urban lakes.  Dog droppings do the same after washing from parks or sidewalks to gutters and sewers, and then down to local lakes and rivers.

Interesting Fact:

One pound of phosphorus can grow up to 500 pounds of algae.

What You The Homeowner Can Do:

You can help protect your watershed health by making simple changes in your lawn care practices.  Check out the tips listed on the "protecting water quality" page and "leaf and grass" page.

Phosphorous-Free Fertilizer - It's The Law!

A new State law enacted in 2003 restricts use of phosphorous fertilizers in Minnesota.  Starting January 1, 2004, lawn fertilizers containing phosphorous cannot be used in the 7-county metro area, including Hennepin County.  Orono residents must use non-phosphorous fertilizers - look for the fertilizer bags with a middle number of "0", such as 22-0-12.