| 词条 | Aquifer Susceptibility |
| 释义 |
An aquifer, according to the Oxford dictionary is a body of permeable rock that can contain or transmit groundwater. Aquifer Susceptibility is the inherent ability of a formation to accept and transmit liquids (potentially including contaminates).[1] Certain areas of the United States are becoming more reliant on groundwater to meet the needs of the population.[2] CausesEveryday, roughly 4.2 trillion gallons of precipitation falls in the United States. About one fourth of that will make its way through the aquifers and become ground water. Shallow and permeable water tables tend to be more susceptible to contamination. In addition, the less rain an area receives the more concentrated the contamination will be. Evapotranspiration can also decrease the amount of water moving downward. Some aquifer susceptibility does happen naturally. Natural chemicals can seep through the aquifers from nearby soil and rocks. However, too much of this can be bad. One of the most common concerns is the amount of chloride and dissolved solids that are found in the water. Federal standards state the maximum for dissolved solids are 500 mg/L, and 250 mg/L for chloride. Dissolved solids and chloride are often found in coastal aquifers and in aquifers deeper than a few hundred feet. Iron and Magnesium can also affect the groundwater. It can also reduce the efficiency of well pumping. While there is not usually a huge amount of nitrogen in groundwater, human involvement can increase it. Federal standards state that the maximum level of nitrogen in groundwater is 10 mg/L. If humans do not interfere, levels generally stay around 0.2 mg/L. However, if levels exceed 3 mg/L, this could mean human involvement. Usually nitrogen is not harmful. But, it has been found to cause methemoglobenimia in infants.[3] The susceptibility of the aquifer also depends on if the aquifer has large or small pores. A rock that has low conductivity level is known as an aquitard. This can constrict the amount of water that is available to use.[4] Effects on groundwaterGroundwater has become very important source of drinking water for over half of the United States. It is especially important in rural areas, where all of the drinking water comes from the ground. Here are some statistics on ground water dependability proved by the groundwater Project Education Policy:[5]
Aquifers are also an important source for the groundwater that feeds into wells. The groundwater must go through these aquifers to get to the well. However, the well has an effect on the aquifers as well. Pumping through much water through these wells can cause a cone of depression around the well.[6] The Virginia Department of Health and the U.S. Geological Survey is conducting a study to determine the susceptibility of aquifers in Virginia. The information is used to determine whether the groundwater is safe enough to drink. The study will take place over a period of four years. The researchers will use Carbon-14 to determine the age of the contamination.[7] PreventionThese aquifers need to be protected from contamination so they can provide clean water. Programs have been put in place to protect this valuable groundwater. These programs include Wellhead and Source Water Protection Program.[8] Close attention also needs to be made in areas near agricultural and urban areas, as these are high risk areas for aquifer susceptibility.[9] References1. ^{{cite journal|last1=Lisenbee|first1=A.L.|last2=Davis|first2=A.D.|last3=Miller|first3=S.L.|title=Aquifer Susceptibility Map of the Pahasapa Limestone (Madison Aquifer) Rapid City West Quadrangle|date=2010}} 2. ^{{cite journal|last1=Lopes|first1=Thomas|title=Quality of Nevada’s Aquifers and their Susceptibility to Contamination, 1994-2004|journal=USGS|date=2004}} 3. ^{{cite journal|last1=Moody|first1=David|title=Sources and extent of Groundwater Contamination|journal=Groundwater Public Policy Leaflet Series}} 4. ^{{cite journal|last1=Gotkowitz|first1=Madeline|last2=Stephen|first2=Gaffield|title=Water-Table and Aquifer-Susceptiblity Maps of Calumet County, Wisconsin|date=2006}} 5. ^{{cite journal|last1=Moody|first1=David|title=Sources and extent of Groundwater Contamination|journal=Groundwater Public Policy Leaflet Series}} 6. ^{{cite journal|last1=Gotkowitz|first1=Madeline|last2=Gaffield|first2=Stephen|title=Water-Table and Aquifer-Susceptiblity Maps of Calumet County, Wisconsin|date=2006}} 7. ^{{cite journal|title=Virginia Aquifer Susceptibility}} 8. ^{{cite journal|last1=Lopes|first1=Thomas|title=Quality of Nevada’s Aquifers and their Susceptibility to Contamination, 1990-2004|journal=USGS|date=2006}} 9. ^{{cite journal|last1=Tesoriero|first1=Anthony|last2=Spruill|first2=Timothy|last3=Eimers|first3=Jo|title=Geochemistry of Shallow Ground Water in Coastal Plain Environments in the Southeastern United States: Implications for Aquifer Susceptibility|journal=Applied Chemistry|date=2004}} 1 : Aquifers |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。