The development of unconventional oil and natural gas resources using horizontal drilling and high-volume hydraulic fracturing has created new demand for wastewater disposal wells that inject waste fluids into deep geologic strata. Deep-well injection has long been the environmentally preferred method for managing produced brine and other wastewater associated with oil and gas production. However, an increasing concern in the United States is that injection of these fluids may be responsible for increasing rates of seismic activity. The number of earthquakes of magnitude 3.0 or greater in the central and eastern United States has increased dramatically since about 2009 from an average of approximately 20 per year between 1970 and 2000 to over 100 per year in the period 2010-2013. Some of these earthquakes may be felt at the surface.

Hydraulic fracturing is a technique developed initially to stimulate oil production from wells in declining oil reservoirs. More recently, it has been used to initiate oil and gas production in unconventional (i.e., low-permeability) reservoirs where these resources were previously inaccessible. This process now is used in more than 90% of new oil and gas production wells. Hydraulic fracturing is done after a well is drilled and involves injecting large volumes of water, sand (or other propping agent), and specialized chemicals under enough pressure to fracture the formations holding the oil or gas. The sand or other proppant holds the fractures open to allow the oil or gas to flow freely out of the formation and into a production well. Its application, along with horizontal drilling, for production of natural gas (methane) from coal beds, tight gas sands, and, more recently, from unconventional shale formations, has resulted in the marked expansion of estimated U.S. natural gas reserves in recent years. Similarly, hydraulic fracturing is enabling the development of unconventional domestic oil resources, such as the Bakken Formation in North Dakota and Montana. However, the rapidly increasing and geographically expanding use of fracturing, along with a growing number of citizen complaints and state investigations of well water contamination attributed to this practice, has led to calls for greater state and/or federal environmental regulation and oversight of this activity. Historically, the Environmental Protection Agency (EPA) had not regulated the underground injection of fluids for hydraulic fracturing of oil or gas production wells. In 1997, the U.S. Court of Appeals for the 11th Circuit ruled that fracturing for coalbed methane (CBM) production in Alabama constituted underground injection and must be regulated under the Safe Drinking Water Act (SDWA). This ruling led EPA to study the risk that hydraulic fracturing for CBM production might pose to drinking water sources. In 2004, EPA reported that the risk was small, except where diesel was used, and that regulation was not needed. However, to address regulatory uncertainty the ruling created, the Energy Policy Act of 2005 (EPAct 2005) revised the SDWA term "underground injection" to explicitly exclude the injection of fluids and propping agents (except diesel fuel) used for hydraulic fracturing purposes. Consequently, EPA currently lacks authority under the SDWA to regulate hydraulic fracturing, except where diesel fuel is used. However, as the use of this process has grown, some in Congress would like to revisit this statutory exclusion. Several relevant bills are pending. H.R. 1084 and S. 587 would repeal the exemption for hydraulic fracturing operations established in EPAct 2005, and amend the term "underground injection" to include explicitly the injection of fluids used in hydraulic fracturing operations, thus authorizing EPA to regulate this process under the SDWA. EPA's FY2010 appropriations act urged the agency to study the relationship between hydraulic fracturing and drinking water quality. The interim report, expected in 2012, may help inform Congress on whether federal action is needed. Meanwhile, numerous states are reviewing or have revised their oil and gas rules to address the increased use of hydraulic fracturing. This report reviews past and proposed treatment of hydraulic fracturing under the SDWA, the principal federal statute for regulating the underground injection of fluids to protect groundwater sources of drinking water. It reviews current SDWA provisions for regulating underground injection activities, and discusses some possible implications of, and issues associated with, enactment of legislation authorizing EPA to regulate hydraulic fracturing under this statute.

As reported July 10, 2012, by the House Committee on Appropriations, Title II of H.R. 6091, the Interior, Environment, and Related Agencies Act, 2013, included a total of $7.06 billion for the Environmental Protection Agency (EPA) for FY2013, $1.28 billion (15.5%) below the President's FY2013 request of $8.34 billion, and $1.39 billion (16.5%) below the FY2012 enacted appropriation of $8.45 billion. Although the House committee-reported bill proposed an overall decrease for EPA, it included both decreases and increases in funding for many individual programs and activities in the eight appropriations accounts that fund the agency compared with the FY2013 requested and FY2012 enacted levels. Since FY2006, Congress has funded EPA accounts within the Interior, Environment, and Related Agencies appropriations. The House committee-reported bill would decrease funding for seven of the eight EPA appropriations accounts compared to the President's FY2013 request, and for six of the accounts relative to FY2012 enacted levels. The largest decrease in H.R. 2061 as reported was for the State and Tribal Assistance Grants (STAG) account: $2.60 billion for FY2013, compared to $3.36 billion requested (23% decrease) and $3.61 billion for FY2012 (28% decrease). This account consistently contains the largest portion of the agency's funding among the eight accounts. The majority of the proposed decrease is attributed to a combined $507.0 million reduction in funding for grants that provide financial assistance to states to help capitalize Clean Water and Drinking Water State Revolving Funds (SRFs). Respectively, these funds finance local wastewater and drinking water infrastructure projects. H.R. 6091 as reported included $689.0 million for Clean Water SRF capitalization grants and $829.0 million for Drinking Water SRF capitalization grants, compared to $1.18 billion and $850.0 million requested for FY2013, and $1.47 billion and $917.9 million appropriated for FY2012, respectively. The STAG account also includes funds to support "categorical" grant programs. States and tribes use these grants to support the day-to-day implementation of environmental laws, such as monitoring, permitting and standard setting, training, and other pollution control and prevention activities, and these grants also assist multimedia projects. The $994.0 million total included for FY2013 for categorical grants in H.R. 6091 as reported is $208.4 million less than the $1.20 billion requested for FY2013, and $94.8 million below the $1.09 billion FY2012 enacted amount. Other prominent issues that have received attention within the context of EPA appropriations include the level of funding for implementing certain air pollution control requirements including greenhouse gas emission regulations, climate change research and related activities, cleanup of hazardous waste sites under the Superfund program, cleanup of sites that tend to be less hazardous (referred to as brownfields), and cleanup of petroleum from leaking underground tanks. Funding needs for the Great Lakes Restoration Initiative, and for the protection and restoration of the Chesapeake Bay and other geographic-specific water programs, also have received attention. In addition to funding priorities among the many pollution control programs and activities, several recent and pending EPA regulatory actions continue to be controversial in the FY2013 appropriations. H.R. 6091 as reported included a number of provisions similar to those considered in the FY2012 appropriations debate (some of which were adopted for FY2012) that would restrict the use of funding for the development, implementation, and enforcement of certain regulatory actions that cut across the various pollution control statutes' programs and initiatives.

In the 109th Congress, key drinking water issues have involved water infrastructure funding and problems caused by specific contaminants, such as the gasoline additive methyl tertiary butyl ether (MTBE), perchlorate, and lead in drinking water. Congress last reauthorized the Safe Drinking Water Act (SDWA) in 1996, and although funding authority for most SDWA programs expired in FY2003, reauthorization bills have not been proposed, as the Environmental Protection Agency (EPA), states, and water systems remain focused on implementing the requirements of the 1996 amendments. One SDWA amendment has been enacted in the 109th Congress. The Energy Policy Act of 2005, Section 322, amended SDWA to preclude the EPA from regulating the injection of any fluids, except diesel fuel, into underground sources of drinking water for hydraulic fracturing purposes related to oil, gas, and geothermal production. Congress also has considered legislation to address concerns about drinking water contamination by perchlorate, the key ingredient in solid rocket fuel. The House passed H.R. 18 and H.R. 186, which would establish groundwater remediation programs in California, where most perchlorate contamination has been identified. Other bills would direct the EPA to issue a SDWA standard for perchlorate. The 107th Congress added drinking water security provisions to the SDWA in the Bioterrorism Preparedness Act. The act required community water systems to conduct vulnerability assessments and prepare emergency plans, and it called for drinking water security research. In the 109th Congress, several bills, including a reported bill, S. 2145, would add further water security requirements for certain water systems. An overriding SDWA issue involves the cumulative cost and complexity of drinking water standards and the ability of water systems, especially small systems, to comply with standards. The issue of the affordability of drinking water standards, such as the new arsenic standard, has merged with the larger debate over the federal role in assisting communities with financing drinking water infrastructure. Congress authorized a drinking water state revolving fund (DWSRF) program in 1996 to help communities finance projects needed to comply with drinking water standards. For FY2006, Congress provided $837.5 million for this program. However, studies show that a large funding gap exists and could continue to grow as SDWA requirements increase and infrastructure ages. The Senate Environment and Public Works Committee has reported S. 1400, the Water Infrastructure Financing Act, to authorize increased funding for the DWSRF and parallel wastewater programs, and to provide grant assistance for small communities. Several other bills would establish a grant program to help small communities comply with drinking water standards and provide greater compliance flexibility for small water systems. This report, which will be updated as warranted, replaces CRS Issue Brief IB10118, Safe Drinking Water Act: Implementation and Issues, by Mary Tiemann.

According to the Centers for Disease Control and Prevention (CDC), 67% of the 246 million people in the United States who receive their water from a public water system received fluoridated water in 2000. One of the CDC's national health goals is to increase the proportion of the U.S. population served by community water systems with "optimally" fluoridated drinking water to 75% by 2010. The decision to add fluoride to a water supply is made by local or state governments. The U.S. Public Health Service (PHS) has recommended an optimal fluoridation level in the range of 0.7 to 1.2 milligrams per liter (mg/L) for the prevention of tooth decay.

Several major statutes form the legal basis for the programs of the Environmental Protection Agency (EPA). Many of these have been amended several times. The current provisions of each are briefly summarised in this report. The Pollution Prevention Act (PPA) seeks to prevent pollution through reduced generation of pollutants at their point of origin. The Clean Air Act (CAA) requires EPA to set mobile source limits, ambient air quality standards, hazardous air pollutant emission standards, standards for new pollution sources, and significant deterioration requirements; and to focus on areas that do not attain standards. The Clean Water Act (CWA) establishes a sewage treatment construction grants program, and a regulatory and enforcement program for discharges of wastes into U.S. waters. Focusing on the regulation of the intentional disposal of materials into ocean waters and authorising related research is the Ocean Dumping Act. The Safe Drinking Water Act (SDWA) establishes primary drinking water standards, regulates underground injection disposal practices, and establishes a groundwater control program. The Solid Waste Disposal Act and Resource Conservation and Recovery Act (RCRA) provide regulation of solid and hazardous waste, while the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), or Superfund, provides authority for the federal government to respond to releases of hazardous substances, and established a fee-maintained fund to clean up abandoned hazardous waste sites. The authority to collect fees has expired, and funding is now provided from general revenues. The Emergency Planning and Community Right-to-Know Act requires industrial reporting of toxic releases and encourages planning to respond to chemical emergencies. The Toxic Substances Control Act (TSCA) regulates the testing of chemicals and their use, and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) governs pesticide products and their use.