PARENT SESSION
64 - Life-Cycle Assessment, Risk Assessment, and Related Tools
2:10 PM to 5:20 PM, Wednesday, 15 May 2002
Session Chair: Jensen, Allan A. ¹, Fullana, Pere ², ^{1 2} .
Stolz A

(64-08) Combining LCA and RA for weed control in municipalities: a case study.

Saft, Robert Jan^*,1, Staats, Natascha², ¹ IVAM Environmental Research/University of Amsterdam, P.O. Box 18180, Amsterdam, The Netherlands² Chemiewinkel/University of Amsterdam, P.O. Box 20242, Amsterdam, The Netherlands

ABSTRACT- Municipalities are the major users of herbicides (glyphosate) for weed control on pavements. The Dutch government puts efforts in decreasing the use of herbicides but, after a few successful years, the use is now increasing again. The main reasons for this are the high costs of alternative methods of weed control (brushing, burning, hot water) and the uncertainty about the environmental benefits of these alternatives. The studies' objective was to provide environmental arguments for municipalities and estimate the direct and indirect costs of weed control. Indirect costs were calculated for removal of glyphosate from drinking water. For the inventory data attention was paid to variabels such as the desired quality of the pavement, effectivity and efficiency of weed control methods, use of materials and fuels and emissions. The LCA instrument was chosen to provide environmental data on a generic scale. It turned out that the normalised effect scores of the themes human toxicity and ecotoxicity were dominant. The first theme was mainly dominated by production and emissions of fuels, the latter one was due to the emission of glyphosate to surface water. A risk assessment was undertaken for the MWTP and surface water due to the run off of herbicides. Predicted concentrations (PEC) in MWTP-sludge and surface water were calculated. No effect concentrations (NEC) were derived with the standard TGD-method. Toxicity data of glyphosate and its metabolit ampa was gathered from literature. The PEC/NEC-ratio exceeds 1 when run off takes place to smaller surface waters. The highest ratio values found (approx. 400) indicate a serious risk for local ecosystems. The results have been disseminated on a large scale to municipalities and other interested parties. They proved to be highly appreciated information for environmental management on a local scale.

Key words: life cycle assessement, risk assessment, weed control, glyphosate