Chesapeake Bay Watershed Nutrient Credit Exchange Program; nutrient credit use by regulated entities. Provides that certain conditions and limitations for municipal separate storm sewer system (MS4) permittees to acquire, use, and transfer nutrient credits for purposes of compliance with any waste load allocations established as effluent limitations in an MS4 permit shall also apply to point source nitrogen or phosphorus credits acquired, used, and transferred by a facility registered under an Industrial Stormwater General Permit or a Virginia Pollutant Discharge Elimination System permit regulating stormwater discharges for compliance with such permit. The bill also provides that such facility may use a compliance plan prepared by the Virginia Nutrient Credit Exchange Association and approved by the Department of Environmental Quality for such purposes in lieu of separate compliance plans.