Summary

Description

Semipermeable devices SPMDs were deployed in wetlands along a railroad rightofway at the Cokeville Meadows National Wildlife Refuge, Lincoln County, Wyoming to determine if hydrocarbons from discarded creosotetreated railroad ties have leached into the wetlands in quantities harmful to fish and wildlife. SPMDs were deployed in three wetlandtie sites and one reference site. Two SPMD deployment devices, each containing two SPMDs, were deployed at three wetland sites containing railroad ties on May 29, 2002. One SPMD deployment device was submerged in the water approximately one meter from the railroad ties and the second was placed approximately five meters from the railroad ties. SPMDs were deployed in water 0.5 to 1 meter in depth. One SPMD deployment device containing two SPMDs was placed in a railroad rightofway wetland without railroad ties reference site. The SPMDs were retrieved approximately 30 days later on July 2, 2002. One sediment sample was collected at each of 4 wetland sites containing old railroad ties and one reference site and analyzed for aromatic and aliphatic hydrocarbons. Thirtyfour wetland sites along the railroad rightofway contained railroad ties. A total of 784 railroad ties were observed in these wetlands with an average of 21 railroad ties at each site. Only two of the 34 sites were located in rightofway adjacent to a refuge tract. The two refuge sites contained 11 and 20 railroad ties, respectively. Hydrocarbon concentrations were below concentrations known to adversely affect sedimentdwelling organisms. Aromatic hydrocarbon concentrations from the SPMDs were extrapolated to water concentrations and all aromatic hydrocarbons were below chronic toxicity levels for aquatic invertebrates.