EPA released guidance to address the effect of the Census Bureau’s revisions to the criteria for defining urban areas related to the EPA’s Clean Water Act Municipal Separate Storm Sewer System (“MS4”) Stormwater Management Permitting Program. EPA is currently evaluating whether revisions to the Phase II stormwater regulations are required in light of this change.
This guidance is available at: https://www.epa.gov/npdes/interim-guidance-census-elimination-urbanized-area-definition