The quality of water delivered by public water systems has been regulated at the federal level since enactment of the 1974 Safe Drinking Water Act (SDWA). Since then, the U.S. Environmental Protection Agency (EPA) has issued regulations for more than 90 contaminants, and all states (except Wyoming) have assumed primary responsibility for administering the federal drinking water program and overseeing public water system compliance. Congress last broadly amended the law in 1996 ( P.L. 104-182 ) in response to criticism that the statute had too little flexibility, too many unfunded mandates, and an arduous but unfocused regulatory schedule. Among the key provisions, the 1996 amendments authorized a Drinking Water State Revolving Fund (DWSRF) program to help public water systems finance improvements needed to comply with federal drinking water regulations and to address the most serious risks to human health. The law authorizes EPA to make grants to states each year to capitalize a state revolving loan fund. Each state must match 20% of its annual capitalization grant. States are authorized to use DWSRF funds to provide financial assistance (primarily subsidized loans) to eligible public water systems for expenditures that EPA has determined, through guidance, will facilitate SDWA compliance or significantly further the act's health protection objectives. More specifically, the law directs each state to develop an intended use plan each year indicating how the allotted funds will be used and requires states to give funding priority to projects that address the most serious human health risks, are necessary to ensure compliance, and assist systems most in need on a per-household basis according to state affordability criteria. The federal grants and state match—combined with funds from loan repayments, leveraged bonds, and other sources—are intended to generate an ongoing source of water infrastructure funding over time. The DWSRF program is patterned after the Clean Water Act State Revolving Fund (CWSRF) program that Congress authorized in 1987 for financing municipal wastewater treatment projects. Projects eligible for DWSRF assistance include installation and replacement of treatment facilities, distribution systems, and certain storage facilities. Projects to replace aging infrastructure are eligible if they are needed to maintain compliance or to further health protection goals. Projects to consolidate water supplies and enhance water system security may also be eligible. DWSRF funds may be used for preconstruction activities. They may not be used to pay for operation and maintenance activities or for projects needed primarily to accommodate growth. Public water systems eligible to receive DWSRF assistance include roughly 50,000 community water systems (whether publicly or privately owned) and 17,500 not-for-profit noncommunity water systems. States generally may not provide DWSRF assistance to systems that lack the capacity to ensure compliance with the act or are in significant noncompliance with SDWA requirements unless these systems meet certain conditions to return to compliance. Systems owned by federal agencies are not eligible. Although the law authorizes assistance to privately owned community water systems, some states have laws or policies that preclude privately owned utilities from receiving DWSRF assistance. The law directs EPA to allot DWSRF funds among the states based on the results of the most recent quadrennial needs survey (discussed under " Drinking Water Infrastructure Needs "), except that each state (including the Commonwealth of Puerto Rico and the District of Columbia) must receive at least 1% of available funds. SDWA authorizes EPA and the states to reserve portions of the available funds for specified purposes. Before distributing funds among the states, EPA reserves 2% of the appropriated amounts for grants to Indian tribes and Alaska Native villages for water infrastructure projects. For FY2017, Congress authorized EPA to set aside as much as $20.0 million for these grants. The law also directs EPA to allot grants to the Virgin Islands, the Commonwealth of the Northern Mariana Islands, American Samoa, and Guam, using not more than 0.33% of the funds available for grants to the states. Congress has regularly increased this amount to 1.5% in appropriations acts. The SDWA further directs EPA to set aside from the annual DWSRF appropriation $2.0 million to pay for monitoring of unregulated contaminants in small and medium systems. EPA may reserve up to $30.0 million annually to reimburse states for operator training and certification costs if separate funding is not provided under Section 1419 of the SDWA. EPA reserved the full amount for several years but reserved none after FY2003, as state training programs had matured. To provide technical assistance to small systems, EPA may reserve up to 2% with a $15.0 million cap. However, Congress has appropriated funding for this activity under Section 1442(e), and EPA has not set aside DWSRF funds for this purpose. The SDWA also includes several set-asides and directives that apply to the states. These provisions offer states flexibility in tailoring their individual DWSRF programs to address state priorities. They also demonstrate the emphasis that the 1996 amendments placed on enhancing compliance, especially among smaller systems. The act requires states to make available at least 15% of their annual allotment for loan assistance to systems that serve 10,000 or fewer persons to the extent that the funds can be obligated to eligible projects. The act also allows states to use up to 30% of their DWSRF capitalization grants to provide additional assistance, such as forgiveness of loan principal or negative interest rate loans, to help disadvantaged communities (as determined by the state). Through appropriations acts, Congress has frequently required states to provide additional subsidization. Among other set-aside provisions, Section 1452(g) authorizes states to reserve a portion of their annual capitalization grants to cover the costs of administering the DWSRF program. Congress increased the amount states may use for administration purposes in the Water Infrastructure Improvements for the Nation Act (WIIN Act; P.L. 114-322 ), enacted on December 16, 2016. States may use an additional portion to help pay the costs of other SDWA mandates. Specifically, states may set aside as much as 10% for a combination of the following: Public water system supervision programs (Section 1443(a)), Technical assistance through source water protection programs, State capacity development strategies (Section 1420(c)), and Operator certification programs (Section 1419). In the WIIN Act, Congress removed the requirement that, in order to use DWSRF funds for the above four purposes, states were to match expenditures with an equal amount of state funds. Section 1452(g) further authorizes states to use an additional 2% of funds to provide technical assistance to systems that serve 10,000 or fewer persons. States also have the option of using as much as 15% for a combination of the following: Loans for the acquisition of land or conservation easements, Loans to implement voluntary source water protection measures, Technical and financial assistance to water systems as part of a capacity development strategy, and Expenditures from the fund for wellhead protection programs. Expenditures may not exceed 10% for any one of these activities. Other SDWA provisions separately authorized funds to be appropriated for several of these activities (e.g., wellhead protection provisions, Section 1428). Congress has generally not provided separate appropriations for these activities, leaving states the option to use DWSRF resources for such activities. To further promote public water system compliance, the 1996 amendments added capacity development and operator certification requirements. Section 1420 required states to establish capacity development programs that include (1) legal authority or other means to ensure that new systems have the technical, financial, and managerial capacity to meet SDWA requirements and (2) a strategy to assist existing systems that are experiencing difficulties in coming into compliance. States were also required to adopt programs for training and certifying operators of community and nontransient, noncommunity water systems. Congress designed the DWSRF program to give states implementation flexibility. Additionally, Congress provided states flexibility in setting priorities between the DWSRF and CWSRF programs to accommodate the divergent drinking water and wastewater needs and priorities among the states. Section 302(a) of the 1996 SDWA amendments authorized states to transfer as much as 33% of the annual DWSRF allotment to the CWSRF or an equivalent amount from the CWSRF to the DWSRF. The act authorized these transfers through FY2001. In 2000, EPA recommended that Congress continue to authorize transfers between the SRF programs to give states flexibility to address their most pressing water infrastructure needs. Several annual appropriations acts had authorized states to continue to transfer as much as 33% of funds between the two programs, and in P.L. 109-54 , Congress made this authority permanent. In the 1996 SDWA amendments, Congress directed EPA to establish the DWSRF program and authorized program appropriations at a level of $599.0 million for FY1994 and $1.0 billion annually for each of FY1995 through FY2003, for a total appropriations authority of $9.6 billion. Although the authorization of appropriations expired in 2003, the program authority has no expiration date, and Congress has continued to provide annual appropriations for the program. Table 1 presents annual appropriations for the program since it began. From FY2000 through FY2009, annual appropriations for the DWSRF program ranged from $820 million to $850 million. For FY2009, Congress appropriated $829.0 million for the program through regular appropriations. The American Recovery and Reinvestment Act of 2009 ( P.L. 111-5 ) provided another $2.0 billion for infrastructure projects through the DWSRF program, for a total of some $2.83 billion in appropriations for this program for FY2009. For FY2010, in P.L. 111-88 , Congress appropriated $1.39 billion for the DWSRF. For FY2011, the President requested $1.29 billion, and P.L.