HR: 10:45h
AN: NB22C-02 INVITED     [Abstracts]
TI: Effects of Road De-icing Salts in Constructed Wetlands
AU: * Silver, P
EM: psb3@psu.edu
AF: School of Science Penn State Erie, Station Road, Erie, PA 16563 United States
AB: In November 2003, a 4-lane highway and 6 mitigation wetlands were opened across the Penn State campus, Erie, Pennsylvania. Road runoff overflows into 1 wetland (T3), and another (R3) receives salt spray and plowed snow. I have logged conductivity and temperature hourly at the sediment-water interface in R3 and T3 since January 2004, and I measure conductivity, temperature, and chironomid density biweekly in all 6 wetlands. Salinity in the wetlands that receive no salt is 0 psu. Biweekly checks of conductivity grossly underestimated winter salinities in T3 and R3. Between January and March 2004, salinity was >5 psu 5 times in R3, and >10 psu 6 times and >30 psu twice in T3. Flushing rates were similar in both wetlands, but time constants were significantly greater in T3 than R3. Salinities returned to 0 psu in both wetlands in May. Chironomid density was significantly lower in T3 than in all other wetlands in summer and autumn, long after salinities at the sediment-water interface returned to 0. Thus, chironomid densities indicated persistent biological effects of de-icers even when measurable salinities were 0 psu. Winter 2005 data show decreasing chironomid density in T3, whereas densities are increasing in the other wetlands.
DE: 0345 Pollution--urban and regional (0305)
DE: 1803 Anthropogenic effects
DE: 1860 Runoff and streamflow
DE: 1890 Wetlands
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly