Biocide levels in surface and groundwater at IPPC licensed wood preservation sites in Ireland

Abstract

The reason the project was undertaken was to assess the level of compliance at Integrated Pollution Prevention Control (IPPC) licensed sites using copper azole based wood preservatives. It was found during the project that there is an issue with biocide levels reported in surface-water and groundwater, namely tebuconazole and propiconazole at these sites, the results of the environmental audit and statistical analysis of available downstream and upstream results, indicate that at sites in agricultural areas that there is a probable outside contribution to surface-water levels at certain IPPC licensed sites. In terms of surface-water monitoring at these sites, where external sources of pesticides might be suspected based on upstream sampling, results suggest that copper analysis is a more robust indicator of compliance. The main finding from the environmental audit was that the level of compliance has improved since 2007 and achieving surface-water and groundwater compliance is well within the grasp of site operators provided they follow the manufactures instructions on use of the product. The case study demonstrated that there are still historical issues associated with the previous use of Chromated Copper Arsenate (CCA) at a number of sites, remediation is ongoing and with the recent move to the copper azole, which has temperature independent fixation properties, the on-site situation should improved provided that manufacturer’s instructions are followed. The main conclusions reached were: • On-site practice in terms of the manner in which timber is presented prior to treatment, post treatment holding times of 48 hours and storage is critical to ensuring compliance with surface-water limits for copper and biocides. • Site monitoring points should include up-stream or up gradient sample points for surface-water and groundwater sampling. • The draft Code of Practice for the Operation of Timber Preservation Plants in an Environmental Conscious Manner, TQBI, 1996, should be revisited by relevant industry bodies and issued formally.