A study was undertaken to demonstrate the effects of a 10-day exposure
to sediments mixed with leachate from marine piles made from southern
pine that were treated with chromated copper arsenate Type-C (CCA-C)
treated to a retention of 40 kg/m(3) (2.5 pcf) and untreated southern
pine piles. The leachates were tested on the benthic amphipod, Ampelis
ca abdita. The biological endpoint used to establish effects was organ
ism survival. Leachate obtained during a 28-day period was dosed onto
both low organic carbon and high organic carbon sediments. The Ampelis
ca abdita were exposed to each type of sediment and were dosed with co
ncentrations of leachates ranging from 10 to 100 percent. The componen
ts of CCA-C, copper, chromium and arsenic, were measured during the pr
eparation of the leachate, in sediment mixtures, and in the overlying
and interstitial water in the exposed vessels. The 10-day exposure was
maintained under static conditions with continuous lighting to ensure
maximum exposure to sediment. Results showed that leaching of copper,
chromium, and arsenic from properly treated and fixed CCA-C-treated w
ood does not occur at concentrations that would adversely affect the s
urvival of these organisms exposed to the sediment, Leachate from the
treated piles also had no significant effect on water quality. The stu
dy is significant, in part, because its design imitated the natural ma
rine environment more closely than other studies published on this top
ic.