THE IMPACT OF AIRPORT DEICING RUNOFF ON WATER-QUALITY AND AQUATIC LIFE IN A PENNSYLVANIA STREAM

The impacts of a large airport on the water quality and aquatic life o f a small (94.8 km(2) drainage area) western Pennsylvania stream were examined. The principal adverse effects of airport runoff were related to runway deicing operations. Microbial metabolism of glycols and ure a utilized as deicing reagents exerted a strong biochemical oxygen dem and in receiving waters. Similarly, the breakdown of urea led to eleva ted concentrations of ammonia. The use of alkaline mill slag as a fill material in the construction of the runways was probably responsible for some elevated alkalinity and pH values from runway leachates. The organic waste load stimulated the growth of dense biological slimes on streambeds, invertebrate communities in waters influenced by airport runoff were severely stressed and dominated by pollution tolerant Chir onomidae and Oligochaeta. The fishery of the watershed was also impair ed, although transient fishes from the nearby Ohio River apparently re invaded the stream at certain times of the year.