Nitrogen and phosphorus are nutrients that are natural parts of aquatic ecosystems. Nitrogen is also the most abundant element in the air we breathe. Nitrogen and phosphorus support the growth of algae and aquatic plants, which provide food and habitat for fish, shellfish and smaller organisms that live in water.
But when too much nitrogen and phosphorus enter the environment - usually from a wide range of human activities - the air and water can become polluted. Nutrient pollution has impacted many streams, rivers, lakes, bays and coastal waters for the past several decades, resulting in serious environmental and human health issues, and impacting the economy.
Sources and Solutions
Excessive nitrogen and phosphorus that washes into water bodies and is released into the air are often the direct result of human activities. The primary sources of nutrient pollution are:
- Agriculture: Animal manure, excess fertilizer applied to crops and fields, and soil erosion make agriculture one of the largest sources of nitrogen and phosphorus pollution in the country.
- Stormwater: When precipitation falls on our cities and towns, it runs across hard surfaces - like rooftops, sidewalks and roads - and carries pollutants, including nitrogen and phosphorus, into local waterways.
- Wastewater: Our sewer and septic systems are responsible for treating large quantities of waste, and these systems do not always operate properly or remove enough nitrogen and phosphorus before discharging into waterways.
- Fossil Fuels: Electric power generation, industry, transportation and agriculture have increased the amount of nitrogen in the air through use of fossil fuels.
- In and Around the Home: Fertilizers, yard and pet waste, and certain soaps and detergents contain nitrogen and phosphorus, and can contribute to nutrient pollution if not properly used or disposed of. The amount of hard surfaces and type of landscaping can also increase the runoff of nitrogen and phosphorus during wet weather.
What You Can Do
We can all take action to reduce nutrient pollution through the choices we make around the house, with our pets, in lawn maintenance, and in transportation. Families, individuals, students and teachers can access resources online to find out more about the health of their local waterways and participate in community efforts to make their environments healthier and safer.
Learn how you can help prevent nutrient pollution:
Cleaning Supplies-Detergents and Soaps
- Choose phosphate-free detergents, soaps, and household cleaners.
- Select the proper load size for your washing machine.
- Only run your clothes or dish washer when you have a full load.
- Use the appropriate amount of detergent; more is not better.
- Always pick up after your pet.
- Avoid walking your pet near streams and other waterways. Instead, walk them in grassy areas, parks or undeveloped areas.
- Inform other pet owners of why picking up pet waste is important and encourage them to do so.
- Take part in a storm drain marking program in your area to help make others aware of where pet waste and other runoff goes when not disposed of properly.
- Inspect your septic system annually.
- Pump out your septic system regularly. (Pumping out every two to five years is recommended for a three-bedroom house with a 1,000-gallon tank; smaller tanks should be pumped more often).
- Do not use septic system additives. There is no scientific evidence that biological and chemical additives aid or accelerate decomposition in septic tanks; some additives can in fact be detrimental to the septic system or contaminate ground water.
- Do not divert storm drains or basement pumps into septic systems.
- Avoid or reduce the use of your garbage disposal. Garbage disposals contribute unnecessary solids to your septic system and can also increase the frequency your tank needs to be pumped.
- Don't use toilets as trash cans. Excess solids can clog your drain field and necessitate more frequent pumping.
- When installing a septic system, maintain a safe distance from drinking water sources to avoid potential contamination. Avoid areas with high water tables and shallow impermeable layers.
- Plant only grass in the drain field and avoid planting trees, bushes, or other plants with extensive root systems that could damage the system's tank or pipes.
- Visit EPA's Septic Smart website to learn more about how your septic system works and simple tips on how to properly maintain it. You can also find resources to launch a local septic education campaign.
- Choose WaterSense labeled products which are high performing, water efficient appliances.
- Use low-flow faucets, shower heads, reduced-flow toilet flushing equipment, and water-saving appliances such as dish- and clothes washers.
- Repair leaking faucets, toilets and pumps.
- Take short showers instead of baths and avoid letting faucets run unnecessarily.
- Visit Conservation for more ideas on how to save water.
For more ideas about how to reduce nutrient pollution visit EPA Nutrient Pollution.