Estimation of toxic contaminant mean concentrations from stormwater quality data

A computer program, runmean (runoffmean), was developed for estimating toxic contaminant mean event concentrations in storm water runoff. For censored runoff concentration data, three estimation methods are used: a replacement method, a regression method, and a modified maximum likelihood method. An input file containing the commonly required information in runoff pollution studies is in a format used in most runoff concentration databases for toxic concentrations. Other options include sub-sample selection from the given data file in six ways: location; land use; pollutant name; time; random; and all samples. Applications of the data processor have been demonstrated on available concentration data. A simple way of selecting an estimation method for runoff quality data using runmean is presented.