Phosphorus (P) is one of the most troublesome pollutants in storm water runoff. Phosphorus comes from many sources, and it is a major cause of water quality problems in our lakes and streams, and a leading contributor to harmful algal blooms.

Everything that is or was living contains phosphorus. It is in leaves. It is in lawn clippings. It is in animal wastes. It is an ingredient in most lawn fertilizers. It is even attached to soil. When leaves, lawn clippings, animal wastes, fertilizers, and soil are picked up by storm water runoff, they are carried directly to our local lakes and streams, providing them with excess phosphorus. This excess phosphorus causes increased algae growth.

You can reduce the amount of phosphorus entering a lake or stream by keeping your leaves and lawn clippings out of the streets and gutters. Leaves and lawn clippings are a major source of phosphorus. When they are swept or washed into the nearest street or storm sewer, they end up in your local lake or stream. Keeping your leaves and lawn clippings out of the streets and gutters will have significant benefits for your local lake or stream.

You can also help by testing your soil before you fertilize. A soil test will tell you how much – if any – fertilizer your lawn needs. Clermont County residents can have their soil tested by the OSU Extension Office at the County Fairgrounds in Owensville for a small fee. They have prepared a short video that shows how to collect a soil sample that can be viewed here.

Adapted from an article published by the New York City Department of Environmental Education.