Nitrate Contamination Of Groundwater

Nitrate Contamination of Groundwater Poses a Serious Health Threat

Nitrates contamination of the world\'s underground water supply poses as
a potentially serious health hazard to the human inhabitants on earth.
High nitrate levels found in well water has been proven to be the cause for
numerous health conditions across the globe. If we intend to provide for
the future survival of man, and life on planet earth, we must take action
now to assure the quality of one of our most precious resources, our
underground water supply.
Ground water can be defined as the water stored in the open spaces
within underground rocks and unconsolidated material (Monroe and Wicander
420). Ground water is one of the numerous parts that make up the
hydrologic cycle. The primary source of water in underground aquifers is
precipitation that infiltrates the ground and moves through the soil and
pore spaces of rocks (Monroe and Wicander 420). There are also other
sources that add water to the underground aquifer that include: water
infiltrating from lakes and streams, recharge ponds, and wastewater
treatment systems. As groundwater moves through the soil, sediment, and
rocks, many of its impurities are filtered out. Take note, however, that
some, not all, soils and rocks are good filters. Some are better than
others and in some cases, serious pollutants are not removed from the water
before it reaches the underground supply.
Now that we have a good working definition of what groundwater is, and
where it comes from, just how important is it? Groundwater makes up about
22% of the worlds supply of fresh water. Right now, groundwater accounts
for 20% of all the water used annually in the United States. On a national
average, a little more than 65% of the groundwater in the United States
each year goes to irrigation, with industrial use second, and third is
domestic use (Monroe and Wicander 420). Some states are more dependent on
groundwater for drinking than others. Nebraska and the corn belt states
rely on underground water for 85% of their drinking needs, and in Florida
90% of all drinking water comes from underground aquifers (Funk and Wagnall
2). People on the average in the United States require more than 50
gallons of water each day for personal and household uses. These include
drinking, washing, preparing meals and removing waste. A bath in a bathtub
uses approximately 25 gallons of water and a shower uses about l5 gallons
per minute of water flow while the shower runs. Just to sustain human
tissue requires about 2.5 quarts of water per day. Most people drink about
a quart of water per day, getting the rest of the water they need from food
content. Most of the foods we eat are comprised mostly of water: for
example, eggs, are about 74% water, watermelon 92%, and a piece of lean
meat about 70%. Most of the beverages we drink are also mostly comprised
of water, like milk, coffee, tea and soft drinks. And the single largest
consumer of water in the United States, is agriculture. In dry areas,
farmers must irrigate their lands to grow crops. It is estimated that in
the United States, more than 100 billion gallons of fresh water are used
each day for the irrigation of croplands (Funk and Wagnall 2).
Since agriculture is the leading user of our groundwater, perhaps it
is fitting, that it is also the biggest contributor of contaminating
nitrates that work into our water supply each year. Agriculture and
livestock production account for 80% of all nitrogen added to the
environment ( Terry, et al. 1996). Industrial fertilizers make up 53%,
animal manure 27%, atmosphere 14%, and point source 6% (Puckett, 1994).
Just how do these nitrates get from the field into our water supply? There
are two primary reasons that nitrate contaminates reach our underground
water supply and make it unsafe. Number one reason is farmer\'s bad habits
of consistently over- fertilizing and applying too much nitrogen to the
soil. In 1995 America\'s agricultural producers added 36 billion pounds of
nitrogen into the environment, 23 billion pounds of supplemental industrial
nitrogen, and 13 billion pounds of extra nitrogen in the form of animal
manure. Twenty percent of this nitrogen was not used by the crops it was
intended. This accounts for about 7-8 billion pounds of excess nitrogen
remaining in the environment where much of it has eventually entered the
reservoirs, rivers, and groundwater that supply us with our drinking water
(NAS 1995). The number two reason these contaminants reach our groundwater
supply runs parallel with the first. Over-irrigation causes the leaching of
these nitrates