The oil and gas industry enjoys exemptions from 7 environment federal laws as follows. For the history around this, please check out this link:
This one also provides a great summary: http://www.nytimes.com/interactive/2011/03/03/us/20110303-natural-gas-timeline.html?_r=0
Safe Drinking Water Act
EPA considered hydraulic fracturing as exempt from the Safe Drinking Water Act following the act’s passage in 1974 (LEAF v. EPA 1997, EPA Fracturing Final 2004). The act sets standards and requires permits for the underground injection of hazardous substances so that these materials do not endanger Underground Sources of Drinking Water (SDWA 2008).
Resource Conservation and Recovery Act (RCRA)
This law sets standards for disclosure and safety in handling hazardous waste, for reducing such waste and for developing non-toxic alternatives (RCRA 2008). In 1988, the EPA and Congress agreed not to apply RCRA to oil and gas wastes, overriding objections from some officials at EPA after the agency had documented 62 cases in which oil and gas wastes had caused damage. Two EPA officials told the Associated Press that the exemption was granted due to industry pressure, a charge that EPA administrators denied (Dixon 1988).
Emergency Planning and Community Right to Know Act (TRI)
Oil and gas is exempt from the federal Emergency Planning and Community Right to Know Act of 1986. The act requires companies to report the release of significant levels of toxic substances to EPA’s Toxics Release Inventory (TRI). The Oil and Gas Accountability Project, a reform organization, has said that the law would likely apply to benzene, toluene and xylene, chemicals often used in oil and gas drilling (OGAP Exemptions 2008).
Clean Water Act
The Clean Water Act sets standards for stormwater discharge. However, oil and gas is exempt from this act despite the potential for significant runoff from thousands of well pads, pipelines and other infrastructure. In 1987, Congress added amendments to the Clean Water Act requiring EPA to develop a permitting program for stormwater runoff. These amendments exempted oil and gas exploration, production, processing or treatment operations, and transmission facilities. However, the EPA considered the standards to apply to construction facilities. Beginning in 1992, the EPA required stormwater permits for oil and gas construction facilities of five acres or more. In the 2005 Energy Bill, Congress extended the exemption to all oil and gas construction facilities (Clean Water Act 2008, EPA NPDES 2006, W&WNews 2006).
Clean Air Act
This law limits emissions of nearly 190 toxic air pollutants, including many emitted by oil and gas companies (Mall et al. 2007, Clean Air Act 2008).
For major sources of air pollution, a company must install the maximum level of pollution control for hazardous emissions that is technically achievable by the cleanest facilities in an industry sector. Smaller sources of emissions grouped together that produce pollution above certain thresholds are generally covered by the act. This aggregation requirement is designed to protect the public from smaller sources that might be relatively harmless on their own but collectively release of large quantities of toxic substances. However, drilling sites are not treated as an aggregated unit under this program (Mall et al. 2007, Clean Air Act).
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) holds most industries accountable for cleaning up hazardous waste. The act, passed in 1980 and amended in 1986, allows the federal government to respond to releases of hazardous substances that threaten human health or the environment. It created a trust fund known as “Superfund” to be used to clean up contaminated sites; the fund is financed via taxes on the chemical and petroleum industries. Congress has since abolished the taxes and pays for the fund through general revenues. As a result, the fund is too small to meet cleanup goals. Yet the liability exemption for drilling companies remains (Mall et al. 2007, CERCLA 2008).
Superfund allows Potentially Responsible Parties (PRPs) to be held liable for clean-up costs for a release or threatened release of a “hazardous substance.” But the law defines this term to exclude oil and natural gas (CERCLA 2008).
National Environmental Policy Act
The National Environmental Policy Act (NEPA), enacted in 1969, exempts certain oil and gas drilling activities, obviating the need to conduct environmental impact statements (EIS) (BLM 2008).
The exemption, enacted by Congress in 2005, effectively shifts the burden of proof to the public to prove that such activities would be unsafe. In 2006 and 2007, the BLM granted this exemption to about 25 percent of all wells approved on public land in the West (BLM Budget 2009).
The activities thus exempted include:
(1) Individual surface disturbances of less than 5 acres so long as the total surface disturbance on the lease is not greater than 150 acres and site-specific analysis in a document prepared pursuant to NEPA has been previously completed.
(2) Drilling an oil or gas well at a location or well pad site at which drilling has occurred previously within 5 years prior to the date of spudding the well.
(3) Drilling an oil or gas well within a developed field for which an approved land use plan or any environmental document prepared pursuant to NEPA analyzed such drilling as a reasonably foreseeable activity, so long as such plan or document was approved within 5 years prior to the date of spudding the well.
(4) Placement of a pipeline in an approved right-of-way corridor, so long as the corridor was approved within 5 years prior to the date of placement of the pipeline.
(5) Maintenance of a minor activity, other than any construction or major renovation or a building or facility (NEPA 2009).
The information above can be found here.