Nitrates

Nitrogen is an element needed by all living plants and animals to build protein. In aquatic ecosystems, nitrogen is present in many forms. Blue-green algae are able to use nitrogen in its molecular form (N2) and convert it into forms of nitrogen that plants can take up through their roots and use for growth: ammonia (NH3) and nitrate (NO-3).

As aquatic plants and animals die, bacteria break down their large protein molecules into ammonia. Ammonia is then oxidized (combined with oxygen) by bacteria to form nitrites (NO-2) and nitrates (NO-3).

Excretions of aquatic organisms are very rich in ammonia, although the amount of nitrogen they add to water is usually small. Ducks and geese, however, contribute nitrogen from their waste, and in areas where they are abundant this can be a problem. Through the decomposition of dead plants and animals, and the excretions of living animals, nitrogen that was previously "locked up" is released.

Because nitrogen, in the form of ammonia and nitrates, acts as a plant nutrient, it also causes eutrophication. Eutrophication is the enrichment of water with nutrients, usually phosphorous and nitrogen, which stimulates the growth of algal blooms and rooted aquatic vegetation. Eutrophication promotes more plant growth and decay, which in turn increases biochemical oxygen demand. Nitrates in excess amounts can have a significant impact on water quality.

Why is the nitrate level in water so high?

Is there an overabundance of blue-green algae in the river or lake?

Check out your local map - can you find a sewage treatment plant nearby?

Do you have septic systems near the river or lake? Are they properly maintained?

Is there a high level of fertilizer use on nearby agricultural fields, lawns or golf courses?

Can you identify possible sources of nonpoint source pollution runoff in your watershed?

Can you find the local storm sewer outlets? Do they directly enter the lake or river?

Can you find any cattle feedlots, dairies or barnyards in the watershed? Is the waste from these feedlots properly contained?

What is the cause(s) of your problem? What did you find that led you to this conclusion?

Now is the time for ACTION!