Clean Water Affordability Act - Amends the Federal Water Pollution Control Act (commonly known as the Clean Water Act) to authorize the Administrator of the Environmental Protection Agency (EPA) to make grants to states for the purpose of providing grants to local or regional authorities or municipalities for use in planning, designing, and constructing treatment works to intercept, transport, control, or treat municipal combined sewer overflows and sanitary sewer overflows and municipalities for such purposes. Requires states or the Administrator to give priority to financially distressed communities.
Requires the Administrator, no later than December 31, 2010 (currently, 2003) and periodically thereafter, to report to Congress on recommended funding levels for sewer overflow control grants.
Requires the Administrator to update the guidance entitled "Combined Sewer Overflows -- Guidance for Financial Capability Assessment and Schedule Development" dated February 1997, to ensure that the evaluations by the Administrator of financial capability assessment and schedule development meet specified criteria, including criteria used in assessing financial capability of a community to make investments necessary to make water quality-related improvements and in implementing water quality-related improvements.
Requires such updated guidance to indicate that it is appropriate for the reconsideration and modification of financial capability determinations and implementation schedules to be based on such criteria.