Stormwater Runoff, also known as nonpoint source pollution (NPS), is pollution that cannot be traced to any specific source, such as a manufacturing plant. Examples include fertilizers, grass clippings, pesticides, motor oil, antifreeze, solvents, detergents, pet waste, 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 sources. Stormwater runoff causes a decline in water quality and harms 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 runoff 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 stormwater runoff threats to the Huron River’s health. 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 of phosphorus can stimulate the growth of 500 pounds of algae. The green “muck” of algae is harmful to aquatic species, and extremely 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 significantly reduce 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 zero or 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
- 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: phosphorus in dishwashing detergents has been banned by law!
During winter, applying salt to our roads and walkways makes it safer for us to get around but it also harms aquatic life by introducing chloride to our waterways. There are ways we can decrease the use of salt:
- At home, shovel more often and don’t over apply salt and sand. Some de-icers work better before a storm so follow directions carefully. Sweep it up and reuse it if you see debris after you need it on the surface. More details on salt and sand for safety at home can be found here.
- Local governments can change the amount of salt applied based on how fast the truck is going. They can also pre-treat the salt, keep exploring alternatives, and carefully track the weather to apply the amount needed to avoid over salting.
Here is a Detroit News article from March 2022: Michigan’s lakes, waterways get saltier. One spot tastes like brine March 2022
Individual behaviors make a difference. By keeping water runoff on site instead of washing down stormdrains, and by using fewer products that compromise the health of water, residents can protect the river, and save time and money in the process.