This rulemaking is mandated under the America's Water Infrastructure Act (AWIA), which became law on October 23, 2018. The AWIA requires EPA to promulgate implementing regulations for section 2010(a), which authorizes State primary enforcement authorities (primacy agencies) to mandate an assessment of restructuring options for a public water system (PWS) that repeatedly violates health-based standards, is unwilling or unable to take feasible corrective actions to return to compliance, or that has unsuccessfully attempted feasible and affordable actions to return to compliance, and for which restructuring is both feasible and could result in greater compliance. The mandatory assessment requirements must be tailored to the water system's size, type, and other factors, and the assessment should not be overly burdensome on the assessed system. A PWS that completes a mandatory assessment is eligible for DWSRF funding to implement the restructuring activities identified in the assessment. The rulemaking will include provisions regarding enforcement relief for a noncompliant PWS that implements a state-approved restructuring plan and liability protection for a "non-responsible" PWS that, based on a completed, primacy-agency-approved restructuring assessment and restructuring plan, consolidates with, or acquires ownership of, an assessed PWS. The AWIA, section 2009(a), also revises the scope of a consolidation plan under the Safe Drinking Water Act (SDWA), subsection 1414(h)(1), to include a contract for significant managerial or administrative functions of a PWS.