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