Development of a model based approach to predict concentrations of pollutants in highway runoff and the risk of adverse environmental impact

In 2003, the Highways Agency in England commissioned a 3 year study based on a systematic approach to measuring pollutants in highway runoff at 24 locations under a range of site conditions. The aim of the study is to develop a model based approach to predict highway runoff pollution concentrations and loads at a site in relation to regional climate, highway and rainfall event characteristics. The study will help to facilitate the Highways Agency’s long term objective of being able to offer improved advice on the circumstances where, and when, highway runoff is likely to have a significant impact. This paper presents initial results from the data collection study; a preliminary comparison of monitoring results with potential standards derived for soluble pollutant impact risk assessment; and, describes the development of a risk assessment tool for pollutants in highway runoff.