Nitrates are a natural part of our biosphere and usually benign.  A vital element to living things, nitrogen may exist as N2 (Nitrogen), NO2- (Nitrite), NO3- (Nitrate), NH3+ (Ammonia), NH4+ (Ammonium) which is constantly recycled in our atmosphere. Also, nitrogen is found in large compounds such as protein and DNA. Nitrates are found naturally in freshwater sources, vegetables, meat and decomposing organic matter. They are nutrients for plants and microorganisms and as such are "yummy".   Along these lines, nitrates are used in such delicious foods such as bologna, sausage, hot dogs and bacon as a preservative.  Nitrates are produced in surface waters by bacteria which produce it from nitrite or from the oxidation of ammonia.

SO WHY SHOULD I CARE ABOUT NITRATE LEVELS ANYWAY?

Elevated levels of nitrate may impact significantly on human life as well as the environment.  High levels of nitrates have caused such conditions as methemoglobinemia (blue baby) and have been linked to non-Hodgkins lymphoma and gastro-intestinal cancers.  Children under the age of six months have not yet developed strong stomach acids which kill bacteria that convert nitrate back to nitrite. This bacteria is different form the aquatic bacteria that run this chemical process in reverse.  Once converted to nitrite, serious problems can occur.

Nitrite binds to hemoglobin.  Hemoglobin is responsible for carrying oxygen in the blood.  When nitrate binds to it, hemoglobin cannot function resulting in shortness of breath, a bluish tint to the skin and fatigue.  Often, parents boil their water before giving it hoping to remove impurities.  Unfortunately this actually concentrates the amount of nitrate in the water because nitrates cannot be boiled away.

WHAT IS CONSIDERED AN ELEVATED LEVEL OF NITRATE AND HOW COMMON IS OVERLOADING?

The Environmental Protection Agency (EPA) lists 10 mg/liter or, 10 parts per million, (ppm) the safe limit for drinking water.  Though it is improving, there have been many cases of nitrate levels above 10 ppm in people's wells. Though an extreme, isolated case, there was actually a well in Nebraska, where the nitrate level  was 150 ppm.   Unfortunately, it is usually a health problem that leads to the discovery of elevated nitrate levels in the drinking water.
 
WHAT ARE SOME FACTORS THAT ELEVATE LEVELS OF NITRATE ?

There are many factors which may lead to elevation of nitrate levels (nitrate loading).  Overuse of chemical fertilizer causes an accumulation of these chemicals in the soil since plants can only absorb so much at one time. Well-drained soils will allow the nitrate to escape from an area if there is rainfall.  The excess product will eventually end up in a waterway.  It may end up in  ponds, reservoirs, or wells used for drinking water.   If the water is chlorinated it will further increase the level of nitrate by accelerating the conversion of nitrite into nitrate.  Also, old, unused wells become reservoirs for chemical runoff.  This water usually becomes quite concentrated and can leak its contamination into new wells.  We have found out that some ponds have water pumped into them from wells. Our study focuses on the effects of chemical fertilizer on nitrate levels.

WHAT CAN BE DONE ABOUT WATER THAT IS HIGH IN NITRATES?

There are several methods in use to reduce the levels of nitrate in water.  Unfortunately many are quite expensive because a nitrate removal system must be installed..  Nitrates can be removed by: proper distillation, reverse osmosis, and anion exchange.  These methods are usually used in homes to remove nitrates from the drinking water.  In water-ways, many communities divide the water source and remove nitrates from half of the water.  Then the treated water is mixed with the nitrate loaded water to dilute the nitrate content.   The best way to reduce nitrates in freshwater is to reduce the amount of commercial fertilizer used.  There are alternative natural materials such as peat moss or bone meal which will act as fertilizers.