Nonpoint source pollution is pollution that cannot be traced to any specific source, such as a manufacturing plant. Examples of nonpoint source pollution include fertilizers, grass clippings, pesticides, motor oil, antifreeze, solvents, detergents, and a variety of common household products – pollutants resulting from our day-to-day activities. In the Huron River Watershed, 50% of the pollutants entering the river come from these pollutants. Nonpoint source pollution cause a decline in water quality and harm the creatures that live in and around the river. Contamination of surface water and groundwater also puts drinking water resources at risk.
Unfortunately, these pollutants enter the Huron River system with considerable ease. Some are intentionally dumped, but most are transported by water runoff. Pollutants “hitch a ride” on the water runoffs from rain, snow melt, and lawn sprinklers, and then travel to the nearest storm drain, ditch, or creek. From there, the polluted runoff water makes its way to the Huron River, unfiltered and untreated.
Excess phosphorus is one of the most serious challenges nonpoint source pollution to the water quality of the Huron River. Phosphorus is a naturally occurring element and an important nutrient in aquatic systems. But, a small amount of phosphorus goes a very long way. As little as one pound can stimulate the growth of 500 pounds of algae. The green “muck” of algae is harmful to aquatic species, and more than annoying to recreational users of the river. As algae and other plant material decompose, oxygen levels in the water are depleted, jeopardizing the entire river system and leaving fish and other aquatic inhabitants “gasping for breath.”
On average, 20% of the phosphorus in the Huron River originates from natural sources. Human activity accounts for the remaining 80%. Using phosphorus-free products – especially fertilizers and dishwashing detergents – can reduce significantly the amount of excess phosphorus entering the river system. Please read the labels for these products!
- For fertilizers, the label on the bag has a middle number that indicates phosphorus content (e.g. 10-10-30). Look for a middle number as close as possible to zero. Buy that product, and support retailers who sell fertilizers with zero phosphorus. Most soils in the Huron River Watershed do not require added phosphorus. For more information on phosphorus in fertilizers, consult the Tips for Yard and Garden web page.
- For dishwashing detergents, phosphorus content can range from 0% to 8.7% (8.7% being the highest content allowed by law). Look for the lowest possible number, and if the label does not tell you the phosphorus content, beware! Note: Recently, phosphorus in dishwashing detergents has been banned by law!
Individual behaviors do make a difference. By keeping water runoff on site, and by using fewer of the products that compromise water quality, residents can help to protect the river, and save time and money in the process. Here are some more links to learn more: