(the returning fluids, which also contain dissolved constituents such as minerals and brine waters). The possibility of groundwater contamination from brine and fracturing fluid leakage through old abandoned wells is low. Produced water is managed by underground injection, municipal and commercial wastewater treatment and discharge, self-contained systems at well sites or fields, and recycling to fracture future wells. Typically less than half of the produced water used to fracture the formation is recovered. In the United States there is over 12 million acres that are being used for fossil fuels. About of land is needed per each drill pad for surface installations. This is equivalent of six Yellowstone National Parks. Well pad and supporting structure construction significantly fragments landscapes which likely has negative effects on wildlife. These sites need to be remediated after wells are exhausted. Research indicates that effects on ecosystem services costs (i.e., those processes that the natural world provides to humanity) has reached over $250 million per year in the U.S. Each well pad (in average 10 wells per pad) needs during preparatory and hydraulic fracturing process about 800 to 2,500 days of noisy activity, which affect both residents and local wildlife. In addition, noise is created by continuous truck traffic (sand, etc.) needed in hydraulic fracturing. Research is underway to determine if human health has been affected by air and water pollution, and rigorous following of safety procedures and regulation is required to avoid harm and to manage the risk of accidents that could cause harm. In July 2013, the US Federal Railroad Administration listed oil contamination by hydraulic fracturing chemicals as "a possible cause" of corrosion in oil tank cars. Hydraulic fracturing has been sometimes linked to induced seismicity or earthquakes. The magnitude of these events is usually too small to be detected at the surface, although tremors attributed to fluid injection into disposal wells have been large enough to have often been felt by people, and to have caused property damage and possibly injuries. A U.S. Geological Survey reported that up to 7.9 million people in several states have a similar earthquake risk to that of California, with hydraulic fracturing and similar practices being a prime contributing factor. Microseismic events are often used to map the horizontal and vertical extent of the fracturing. A better understanding of the geology of the area being fracked and used for injection wells can be helpful in mitigating