Assessment of Benthic Macroinvertebrate and Fish Communities in a Stream Receiving Storm Water Runoff from a Large Airport

Abstract

ABSTRACT Prior to the opening of Denver International Airport, Stapleton International Airport (SIA) was the major airport in Colorado. Typically, storm water runoff from SIA was collected and directed to a water treatment facility. However, during winter months when deicers were being used, heavy snows or rains periodically taxed the capacity of the storm water collection system and untreated water was diverted directly into Sand Creek. A study was conducted to determine if the benthic macroinvertebrate and fish communities in the creek had been permanently influenced. Samples for chemical and biological analysis were collected at sites upstream and downstream of the airport outfalls. No ethylene or propylene glycol was found in the creek. Benthic macroinvertebrate communities were dominated by pollution-tolerant organisms, with chironomids being the most abundant group. Benthic macroinvertebrate density and diversity downstream of the storm-water outfalls were not significantly different from those at the upstream sites. The most abundant species of fish collected in Sand Creek were creek chub (Semotilus atromaculatus), white sucker (Catostomus commersoni), and fathead minnow (Pimephales promelas). These species dominated the catch at all sites. Fish were most dense downstream of the storm water outfalls; no evidence of stream degradation due to SIA could be found. Sand Creek is an urban stream, historically impacted by chemical and physical perturbations. Fish and benthic macroinvertebrate abundance and diversity in Sand Creek are most likely dictated by available habitat and pre-airport water quality.