This project presents research findings pertaining to the implementation of a comprehensive monitoring program for characterization of North Carolina highway runoff. Ten monitoring sites were included in the study. The sites were distributed in the Piedmont region (6), the mountain region (2), and the coastal region (2). Contributing drainage areas ranged from 0.15 to 13.26 acres. Roadway imperviousness ranged from 22% to 100%; traffic volumes, measured in vehicles a day (both directions) ranged from 9,400 to 78,800. Rainfall-runoff data and composite storm water samples were obtained from 237 storm events. The effectiveness of vegetative best-management practices (BMPs) was assessed by comparing pollutant exports from three groups of paired monitoring sites. A database was established for estimation of seasonal and annual pollutant loads and event-mean-concentrations (EMCs). The study was part of NCDOT's effort to comply with National Pollution Discharge Elimination System (NPDES) requirements.
