Cataloging Information
Ecological - Second Order
Aquatic Life
Water
Ammonium-based fire retardants are important in managing wildfires, but their use can adversely affect water quality. Their entry, fate, and impact were studied in five forest streams. Initial retardant concentrations in water approached levels which could damage fish, but no distressed fish were found. Concentrations decreased sharply with time after application and distance downstream, and there was no long-term entry. The numbers and kinds of stream insects were not affected. Simulations of retardant dispersal in streams showed fish mortality might occur from zero to more than 10,000 m below the point of chemical entry, depending on application parameters and stream characteristics. Guidelines to minimize adverse impacts from the use of fire retardants are suggested.