Environmental Issues ( Critque) - Article Example

One set of risks are specific to the hydraulic fracture process used for shale gas production while the other set of risks apply to all oil and gas production activities where there is much greater operating experience. The last part of the paper shows that the environmental regulations for shale gas drilling vary from state to state and that there are areas of overlap between some of the state regulations and some federal laws. The paper suggests the need for a common set of regulations so that the best practices developed at one drill site can be applied across all projects. 2. Environmental risks specific to shale gas production 2.

1 Seismic shocks The major concerns about shale gas production have been around the hydraulic fracture process where the shale rock is caused to fracture by hydraulic pressure. The cracks in the rock propagate 500 to 800 feet in all directions from the casing pipe and the effect is similar to an underground seismic shock. The fracture pressure needs to be monitored and controlled to prevent the cracks from spreading beyond the shale gas layer (page 4). The general concern with setting off such underground fractures is that the fissures may permit contamination of underground water aquifers that are used for drinking water (page 7).

Most shale gas formations are found 4,000 to 8,500 feet below the surface whereas drinking water sources are rarely more than 850 feet deep (page 8). Seismic monitoring is an essential tool to ensure that the underground cracks do not spread beyond the shale gas formation. However, only 3% of around 75,000 hydraulic fractures carried out in 2009 in the US were seismically monitored (page 8). An additional concern is with such underground fracture may lead to earthquakes. The town of Cleburne, Texas has experienced several low intensity earthquakes under 3.3.on the Richter scale in 2008 and 2009 after the start of shale gas exploration in the area when the region has no recorded earthquakes in the previous 142 years (page 9).

Preliminary studies do not find a definite link between shale gas exploration and these earthquakes but the concern remains. The paper does not say whether the hydraulic fractures in the Cleburne area were seismically monitored. 2.2 Fresh water usage and waste water disposal Hydraulic fracturing requires 2 to 8 million gallons of water per well fractured. Though water once used for fracturing can be reused by diluting with fresh water, the Barnett Shale project has used an average of 3 million gallons of fresh water per well and has drilled tens of thousands of such wells (page 12).

Apart from the problem of using so much water in competition with other uses, there is the problem of treatment and disposal of contaminated water. The water pumped into the well has chemical additives. When it flows back to the surface it includes any sub-surface water that may have dissolved contaminants such as arsenic, benzene and mercury (page 10). The ‘flow back’ water will happen not just during the hydraulic fracture process but also during the gas production phase of the well. The water is presently being injected into underground saline aquifers but the number of such wells available is too small to handle the volumes of waste water (page 10).

Municipal waste water treatment facilities in the area of the shale gas fields cannot handle this volume of water and are not designed for these contaminants. Treated municipal water is also