In this study, the Regional Transportation District's (RTD's) light rail operations were examined for pollutant production and runoff. Conclusions from the study: Water leaving ballasted tracks carries only a small fraction of the heavy metals that are introduced into tracks from the light rail operations. Heavy metal concentrations at the most heavily traveled light rail station showed that pollutant concentrations were far below the regulatory limits.
Currently, CDOT has no uniform statewide procedure to size detour drainage structures and permanent hydraulic structures using existing methodologies may result in failures. The main objective of the study is to develop a statewide detour drainage structure design procedure that also considers environmental impacts and mitigation measures.
A new service life chart for steel pipes was developed based on the information collected from the field observations and data analysis. Pipe failure criteria were established in accordance with the ongoing culvert evaluation procedure along I-70 and I-25. For the steel pipe failure cases along I-70 and I-25, the previously published service life predictors for steel pipes deviated from observations by as much as 10 times.
In this study, the Regional Transportation District's (RTD's) light rail tracks were modeled to determine the Rational Method runoff coefficient, C, values corresponding to ballasted tracks. The runoff coefficient for ballasted tracks is significantly larger than the previously tabulated values for railroad yards. The higher runoff coefficient reflects the design of ballasted tracks to drain rainfall as quickly as possible.
