The Environmental Protection Agency (EPA) estimates that more than $680 billion is needed to repair and replace water and wastewater infrastructure nationwide over the next 20 years. Under the Clean Water Act and Safe Drinking Water Act, the federal government contributes some funding to states through EPA's Clean Water and Drinking Water state revolving funds (SRF) programs. States use this funding to make low-or no-interest loans to communities to build water and wastewater infrastructure, in addition to other assistance. These loans are repaid with interest, and these funds are then used for future loans. This book examines factors that affect selected states' abilities to sustain their SRF funds; selected states' actions to enhance their SRF funds and views about sustaining the funds; and steps that EPA takes to review states' abilities to sustain their SRF funds as part of its oversight.