	Introduction

The Safe Drinking Water Act (SDWA), Title XIV of the Public Health Service Act, is the key federal law for protecting public water supplies from harmful contaminants. First enacted in 1974 and substantially amended in 1986, 1996, and 2016, the act is administered through programs that establish standards and treatment requirements for public water supplies, finance drinking water infrastructure projects, promote water system compliance, and control the underground injection of fluids to protect underground sources of drinking water. The 1974 law established the current federal-state arrangement in which states may be delegated primary implementation and enforcement authority for the drinking water program. The state-administered Public Water Supply Supervision (PWSS) Program remains the basic program for regulating the nation's public water systems, and 49 states have assumed this authority. In the SDWA amendments of 1996, Congress reauthorized appropriations for most SDWA programs through FY2003. Although the authorization of appropriations has expired for most provisions, Congress has continued to appropriate funds for the ongoing SDWA programs. Enacted in December 2016, the Water Infrastructure Improvements for the Nation (WINN) Act, P.L. This report summarizes the act's major provisions, programs, and requirements and provides statistics on the universe of regulated public water systems. Located at the end of the report, Table 2 cross-references sections of the act with the major U.S. Code sections of the codified statute, and Table 3 identifies authorizations of appropriations under the act. The first major amendments ( P.L. 104-182 ). In 2002, several drinking water security provisions were added to the SDWA through the Public Health Security and Bioterrorism Preparedness and Response Act of 2002 ( P.L. 107-188 ). 113-64 ] explicitly exempted fire hydrants from coverage under the act's lead plumbing restrictions. ) Enacted August 7, 2015, the Drinking Water Protection Act ( P.L. 114-45 ) directed EPA to develop a strategic plan to assess and manage the risks associated with algal toxins in public drinking water supplies. Enacted December 11, 2015, the Grassroots Rural and Small Community Water Systems Assistance Act ( P.L. Included in the Safe Drinking Water Act of 1974 ( P.L. The WIIN Act ( P.L. The agency is directed to provide technical assistance to the states and municipalities in administering their public water system regulatory responsibilities.
This report summarizes the Safe Drinking Water Act (SDWA) and its major programs and regulatory requirements. It reviews revisions to the act since its enactment in 1974, including the drinking water security provisions added to the SDWA by the Public Health Security and Bioterrorism Preparedness and Response Act of 2002 (P.L. 107-188) and lead reduction provisions as amended by P.L. 111-380 (including amendments made by P.L. 113-64 to explicitly exempt fire hydrants from coverage under the act's lead plumbing restrictions). It also reviews P.L. 114-45, enacted August 7, 2015, directing the Environmental Protection Agency (EPA) to develop a strategic plan to assess and manage the risks associated with algal toxins in public water supplies; P.L. 114-98, the Grassroots Rural and Small Community Water Systems Assistance Act, enacted December 11, 2015; and P.L. 114-322, the Water Infrastructure Improvements for the Nation (WIIN) Act, enacted December 16, 2016.
The SDWA, Title XIV of the Public Health Service Act, is the key federal law for protecting public water supplies from harmful contaminants. First enacted in 1974 and substantially amended and reauthorized in 1986 and 1996, the act is administered through programs that establish standards and treatment requirements for public water supplies, promote compliance capacity of public water systems, provide technical assistance to small water systems, control the underground injection of fluids, finance infrastructure projects, and protect sources of drinking water. The 1974 law established the current federal-state arrangement in which states may be delegated primary implementation and enforcement authority (primacy) for the drinking water program and the underground injection control (UIC) program. The state-administered Public Water Supply Supervision (PWSS) Program remains the basic program for regulating the nation's public water systems, and 49 states have assumed this authority.
In the Safe Drinking Water Act Amendments of 1996 (P.L. 104-182), Congress reauthorized appropriations for most SDWA programs through FY2003. As with other EPA-administered statutes having expired funding authority, Congress has continued to appropriate funds for the ongoing SDWA programs.
In addition to reviewing key programs and requirements of the SDWA, this report includes statistics on the number and types of regulated public water systems and lists all major amendments with the year of enactment and public law number. Located at the end of the report, Table 2 cross-references sections of the act with the major U.S. Code sections of the codified statute, and Table 3 identifies authorizations of appropriations under the act.
This report expands on a brief discussion of the SWDA in CRS Report RL30798, Environmental Laws: Summaries of Major Statutes Administered by the Environmental Protection Agency. That report provides summaries of the principal environmental statutes administered by EPA.