PCP in aquatic environments arising from historic contamination at wood processing and preservation sites
J S Gifford, P N McFarlane, M C Judd, S M Anderson
Three different studies are reported that assess the impacts of Pentachlorophenol (PCP) in aquatic environments arising from its historic use at sawmilling and wood preservation sites. These studies involved New Zealand wood processing facilities, and collectively they aimed to measure the transport of PCP from sawmill sites into the aquatic environment, determine the background environmental concentration of PCP in isolated lakes of New Zealand, and assess the relative contribution of PCP from different potential sources, such as sawmills, urban areas and agricultural catchments. The PCP concentrations in water, sediment and biota from a lake catchment, near a major wood processing site, indicated that low level contamination had occurred. PCP levels in lake sediments and freshwater mussels were elevated compared to New Zealand remote lake sites but similar to comparable locations reported in the international literature. Water concentrations of PCP in the lake were less than the most stringent international water quality guidelines for the protection of aquatic life. Water and sediment PCP concentrations in streams within the catchment, isolated from point sources, were less than the detection limit. The PCP concentration found in sediments ( £ 1.3 ng.g-1 DW) from the remote lakes, reflects a New Zealand background concentration. The source of PCP in remote lake sites is unknown, though it is unlikely to be directly from the sawmilling industry. Although the historic use of PCP by the sawmilling industry appears to have caused localised contamination near areas of high use, the current evidence suggests that it has not lead to widespread contamination of New Zealand aquatic environments.