The USEPA and other regulatory agencies are considering significant changes to their stormwater regulatory programs. Two areas currently being discussed under the draft federal stormwater rules are: 1) requiring retrofit practices to reduce stormwater pollution from existing urban lands, and 2) setting objective (or numeric) stormwater quality goals. This paper will explain the challenges and achievements of a state stormwater program that has already incorporated these two issues in their permit program. Permitted communities compare a “Base Conditions” to “Existing Conditions” to determine their current level of pollution reduction. If the community is not at the specified reduction then they are required to implement additional stormwater control measures (SCMs) until they achieve the permit goal. This paper explains the process the City of Fond du Lac, Wisconsin went through to evaluate the pollution loading from their MS4 system and then implement a plan to meet their regulatory requirements.