Fertilizers and pesticides are among the many common stormwater pollutants that can degrade water quality. Though fertilizers contain chemicals that are good for lawns and plants when used properly, excessive amounts applied to lawns and gardens wash off and pollute streams.
Fertilizers are made of nutrients, such as nitrogen and phosphorus. When it rains, these nutrients are carried by stormwater into the nearest stream, river, or other water body. Too many nutrients in water can cause algae to grow, which uses up the oxygen in the water. Low levels of oxygen in water can hurt aquatic wildlife and even lead to fish kills.
Water pollution problems from fertilizers can be diminished by following these guidelines:
- Use pesticides and fertilizers sparingly. When use is necessary, use these chemicals in the recommended amounts. Read the label. More application does not mean a greener lawn - it means more watering and mowing.
- Water the lawn with about 1/4-inch to 1/2-inch of water after a fertilizer application. This helps move the fertilizer into the soil and reduces the potential of being lost in stormwater runoff.
- Never apply fertilizers if a heavy rain is anticipated.
- If you spill fertilizers, sweep them up, do not hose or sweep them into the streets and storm drains.
Pesticides are any substance or mixture of substances intended for preventing or destroying pests. The term applies to herbicides, fungicides and other substances used to control pests.
Water pollution problems from pesticides can be diminished by following these guidelines
- Before using a pesticide, make sure that it is actually needed. Verify that pests are the root of the problem and that they are not simply covering up a deeper issue.
- Allow some pests in your yard. Some insects are actually beneficial to your yard. If a particular plant is consistently plagued by pests, replace it with a more pest-resistant one.
- A diversified yard with a variety of plants will ensure the protection of the rest of a yard, should pests attack.
- Use spot treatment to avoid abuse of pesticides
- Use organic mulch or safer pest control methods whenever possible.
- Check with Cooperative Extension for additional information on pesticides and alternatives.
When it rains, nutrients from fertilizers are carried by stormwater into the nearest stream, river, or other water body, and become a major source of water pollution. Too many nutrients in water can cause algae to grow, which uses up the oxygen in the water, harming aquatic life. You may not see the effect of fertilizers and pesticides in stormwater right where you live, but their detrimental effects are very apparent in North Carolina’s rivers and estuaries