Odor and appearance issues are often related to the presence of algae that multiplies rapidly in waters that is nutrient enriched. Algae are simple plants that grow in many forms. Thick layers of algae, called blooms, may form when nutrients are added to the water in amounts in excess of naturally occurring nutrients. Fertilizers, pet waste, improperly functioning septic tanks, grass clippings, leaves, and other yard wastes are sources of nutrients. Increased algae populations sometimes upset the natural balance of life in water because during algae decomposition, oxygen is removed from the water and may cause fish to die. Blooms of algae can give the water an unpleasant taste or odor; reduce clarity; and color the water body a vivid green, brown, yellow, or red.
One type of algae, called blue-green algae, is different from other algae. Lakes with large numbers of blue-green algae usually appear blue-green in color; but some of these blooms can appear reddish, brownish or even black. Blue-green algae blooms most often occur in late summer. A few species of blue-green algae are toxic and can poison animals that drink water containing these organisms.
If you live on a lake with algae blooms, try to help reduce the amount of nutrients entering the lake. Practices such as leaving a natural area along the lakeshore and getting your soil tested before fertilizing your lawn can help reduce nutrient inputs to the lake. Other tips can be found in the publication called “Your Lake and You” or “Practical Tips for the Home and Yard to Protect Water Quality.” You can obtain these documents through the EGLE Environmental Assistance Center at 800-662-9278. For soil sampling kits, contact your county Michigan State University Extension Office. A list of local extension services can be found at https://www.canr.msu.edu/outreach/county, or a local office can be found in a telephone book.
To learn if a lake has problems with nutrient pollution, observe the lake during the summer months or ask lakefront owners about their observations of aquatic plants and algae. Lake associations may have water quality surveys, reports, or could be involved in volunteer water quality monitoring programs. A list of Michigan lake associations is available at https://mymlsa.org/ or you can ask lakefront owners if they have an organized lake association. For information on the Michigan Clean Water Corps (MiCorps), Michigan’s statewide volunteer monitoring program, visit https://micorps.net/. This web site page contains information about the Cooperative Lakes Monitoring Program (CLMP), individual lake reports, and provides details about how to become a volunteer.
Some organizations strive to improve water quality within various watersheds. Most of these organizations collect water quality data and summarize their findings for the public. If you would like to see if a watershed group exists for a lake (or river), visit the U.S. Environmental Protection Agency’s watershed organization listing at https://www.epa.gov/waterdata/surf-your-watershed. You can also contact EGLE's Environmental Assistance Center at 800­-662-­9278, or call any EGLE district office, or contact Water Resources Division's Nonpoint Source staff.