Ground Water Pollution
... down through the soil to the saturated zone where water fills all the spaces between soil particles and rocks. When ground water comes to a lake, stream, or ocean, it discharges from the ground and becomes surface water. This water then evaporates into the atmosphere, condenses and becomes precipitation. Ground water is an important component of our nation’s fresh water resources. Ground water contamination is affected by many of the following factors. One is the distance between the land surface where pollution occurs and the depth of the water table. Two is the greater the distance, the grater the chance that the pollutant will biodegrade or react with soil minerals. Three is the mineral composition of the soil and rocks in the unsaturated zone. Heavy soil and organic material lessen the potential for contamination. Finally the fourth is the amount of rainfall, less rainfall results in less water entering the saturated zone and therefore, lower quantities of contaminants. The main sources of ground water pollution are Underground Storage Tanks, Landfills, Septic System, Industrial Wastes, and Agricultural Sources. Underground Storage Tanks are the greatest potential source of ground water pollution. According to the Environmental Protection agency estimates that 15 % of all underground fuel storage tanks are leaking. Underground Storage tanks holding petroleum products, acids, solvents and chemicals can develop leaks from corrosion, defects, improper installation, or mechanical failure of the pipes and fittings. Landfills have long been used to dispose of wastes. Landfills were generally sited on land considered to have no other uses. Unlined abandoned sand and gravel pits, old strip mines, marshlands and sinkholes were often used. In many instances, the water table was at, or very near the ground surface and the potential for ground water contamination was high. Septic Systems are a major cause of ground water contamination is outflow from septic tanks. Misuse of this system for disposal of anything other than domestic or sanitary waste can pose a substantial threat to ground water and makes the system subject to Federal regulation. Residential waste water systems can be a source of many categories of contaminants, including bacteria, viruses, nitrates from human waste, and organic compounds. Industrial Practices is another main source of gr...