In helping the Pennsylvania Department of Transportation (PennDOT) meet MS4 compliance requirements for their maintenance facilities and roadways throughout the state, we’ve benchmarked practices of other state departments of transportation, developed strategies for inventorying stormwater control measures at PennDOT facilities, and defined and mapped high-priority areas. We’ve conducted gap analyses on maintenance procedures, developed and coordinated the illicit discharge detection and elimination program, created inspection checklists, and mapped inventories for MS4 reporting to the U.S. Environmental Protection Agency and the Pennsylvania Department of Environmental Protection.