nitrogen+test



Nitrogen is an important part of the nitrogen cycle in our environment. Too much nitrogen in a stream can be unhealthy. When high levels of nitrates (compounds with nitrogen) enter the stream, this can be bad for the environment.

Unpolluted waters should have a nitrate level 1.0 mg/L or lower The Mill Creek average is between 2 - 3 mg/L

Nitrate levels that are 10 mg/L or higher can be hazardous to drinking water.


 * What might cause high levels of nitrates in a stream? **

As we learned in the fall, nitrogen is very important to bacteria and plants in our campus garden. However, too much nitrogen may affect the ecosystem. In the fall and spring, we took N, P, K tests of our soil in each garden. We were testing for levels of nitrogen, potassium, and phosphorous in the soil. After taking these tests, we found some gardens had depleted levels of nitrogen. We were able to improve and amend the soil by adding fertilizer, which contains nitrogen, potassium, and phosporous.

We live in a highly populated residential environment outside of a city. Farms have plenty of animals whose manure and waste may enter the stream and increase the nitrate levels. Finely manicured lawns in the neighborhood and local golf courses can contribute to increased levels of nitrogen in the stream.

A few years ago, our class actually tested a stream in Havertown in Merwood Park. We found high nitrate levels and realized upstream there were many residential homes and the Merion Golf Course. A large summer flood in August of 2009 also contributed to the erosion and degradation of the stream.


 * What are ways to protect our stream from excess amounts of nitrates? **

Perhaps there are ways to control the amounts of nitrogen used in our yards, golf courses, and farms. Perhaps there are ways to filter the nitrogen out of the water before it hits the stream. Are there native plants we can put in back yards and golf courses that require less water and fertilizer to care for them? Building plenty of plants around the banks of our streams may help the water travel up the plants by transpiration and avoid future flooding and erosion. Many volunteers and groups such as the Lower Merion Conservancy are making an effort to keep our local streams clean and healthy.