Rainfall and runoff were monitored for about one year at five sites on two small airports located in the Piedmont region of NC. Land use in the drainage areas to the five sites were representative of the airside of small airports with three sites (INT-Run, INT-Taxi, and BUY-Taxi) on the runway/taxiway area and two sites (INT-Term and BUY-Apron) on the terminal apron area. Flow-proportional samples of runoff were collected during at least 20 storms and analyzed for total Kjeldahl nitrogen (TKN), nitrate+nitrite nitrogen (NOx-N), total phosphorus (TP) and total suspended solids (TSS).
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Rainfall-runoff relationships for three of the four sites were similar to those from conventional residential development while one taxiway site (BUY-Taxi) was similar to a residential low impact development (LID). Concentrations of TN, TP, and TSS in runoff from all five airport sites were less than those from urban runoff across the U.S. and less than those reported for several residential areas of NC, but they were greater than some of those reported for commercial areas. Mean concentrations of TP and TSS for all five sites and TN for 4 of the 5 sites were less than the corresponding concentrations at which stormwater control measures become less or not effective. Cumulative storm event load data documented that both terminal and one runway/taxiway sites had annual TN, TP, and TSS export was less than conventional residential sites of NC, but greater than two LID residential areas. One taxiway (BUY-Taxi) site had TN, TP, and TSS export less than or equal to that reported for a residential LID.
