Characteristics of non-point source pollutants on a railway bridges

The railway industry is receiving more attention these days in accordance with the high technologies being introduced into the industry. However, the research on the railway facilities has been inadequate. The interest on non-point source pollution is increasing in an effort to protect the quality of the water system. In this study, the data of the concrete road-beds on railway bridges, the runoff characteristics, event mean concentration (EMC), and pollutant load per unit area were assessed. The railway bridge concrete road-bed areas typically show the first-flush effect, whereas the railway bridge gravel road-bed areas show a two-peak effect on the runoff characteristics of non-point source pollution. The pollutant unit load and EMC in the concrete road-bed areas have also been found to be higher than those in gravel road-bed areas. The pollutant load per unit area around railway facilities shows more non-point source pollutants than other areas. The values of heavy metals and oil and grease (O&G) pollutants more washed out than heavy metals and O&G pollutants in the pavement and urban areas. The non-point source pollutants are the main type of the pollutants around the railway facilities. In order words, it is necessary to control non-point source pollution in the railway-bridge gravel road-bed areas.