The effects of chromated copper-arsenate (CCA) pressure-treated wood on local sediments and benthos in a freshwater lake
Date of Award
Master of Science in Environmental Science - (M.S.)
Chemical Engineering, Chemistry and Environmental Science
Judith S. Weis
Richard B. Trattner
This study looked at the sediment and benthic organism effects of exposure to a Chromated Copper-Arsenate (CCA) treated wood bulkhead in a lake environment with respect to 1) the leaching and accumulation of chromium, copper and arsenic in the nearby sediments, 2) accumulation of these metals in local benthic organisms and 3) the effects of these metals on the local benthic community structure. Sediment samples, taken at regular distances away from a CCA bulkhead and three reference areas in a freshwater lake in Wayne, NJ, were sieved to remove the fine particle fraction (<70µm) which was then analyzed for the metals of concern. Benthic organisms were sampled at the same locations, enumerated, identified, dried and also analyzed for the metals in question. Analysis of sediment metal concentrations revealed high levels of copper at all sampling locations. This was attributed to the annual addition and accumulation Of CuS04 added to the lake. There was no significant increase in chromium or arsenic concentration adjacent to the bulkheads. Although not significant, the sediment did exhibit a higher arsenic concentration adjacent to the CCA bulkhead than at the reference areas. Benthic organism metal analysis showed a trend towards increased tissue levels for the three metals in organisms collected adjacent to the wood bulkhead. This suggested that bioaccumulation of these metals was greatest at this location where leaching of these metals could have occurred. Unfortunately this could not be statistically demonstrated due to the small sample size obtained (n = 1). Although not statistically significant, analysis of benthic organism community structure revealed that total biomass and Shannon-Wiener diversity index were lowest adjacent to the CCA bulkhead compared to the reference sampling locations. The results suggest that the leachate of CCA-treated wood may increase metal concentrations in the local sediments and benthic organisms and therefore may have potential deleterious effects upon the local benthic community. Further studies will need to be performed to prove statistically whether there is a need for concern over the addition of CCA-treated wood bulkheads in freshwater.
Romeo, William A., "The effects of chromated copper-arsenate (CCA) pressure-treated wood on local sediments and benthos in a freshwater lake" (1996). Theses. 1060.