Phosphorus removal by urban runoff detention basins

Abstract

An empirical model previously developed for predicting phosphorus retention in reservoirs is tested against the urban lake/detention pond data set. Detention pond design criteria developed under the EPA’s Nationwide Urban Runoff Program (NURP) are ovaluated using the model. For summer precipitation and runoff quality typical of St. Paul, Minnesota, a basin designed according to NURP criteria is estimated to have a long-term-average phosphorus removal efficiency of 47–68 percent. For a given loading regime, phosphorus removal is shown to be more sensitive to pond depth than to surface area. Specific design features for enhancing phosphorus removal (deepening, promoting infiltration, promoting plug flow, and chemical treatment) are discussed. The methodology can be used to evaluate wet detention pond design criteria in other regions, with substitution of appropriate precipitation and runoff quality characteristics. © 1987 Taylor & Francis Group, LLC.