WRRCTMR No.45 Estimation of Urban Stormwater Quality in Kalihi Stream Drainage Basin, Oahu, Hawaii

Abstract

Urban runoff pollution potential can be linked to the constituents of street wastes as these wastes constitute the principal portion of runoff contaminants. This study was an attempt to correlate pollution associated with street litter with baseline quality data acquired in a previous study of Kalihi Stream. Correlations were made between street sweepings quality, length of street, land use, street surface characteristics, and rainfall intensity in order to estimate the concentration of pollutants in urban stormwater. The overall comparability of obtained estimates with existent stormwater quality data suggests the possibility of obtaining fairly acceptable quantification of pollution potential attributable to urban runoff by utilizing procedures described. However, the number of assumptions required leads to some inadequacies as reflected in inconsistencies in predicted BOD5 and COD levels with actual field data. The good correlation of population density-based formulae for street length with actual street lengths indicates a simple method for approximating street refuse pollution based on loadings per length of curb.