The Science of the Total Environment 185 (1996) 27-44 the Science dthe WalEnvironarmt A.k-mM-4C-rltscl.swk- ~th.-dk-~w,. Monitoring and prioritisation of organic contaminants in sewage sludges using specific chemical analysis and predictive, non-analytical methods M.D. Webber* a, H.R. Rogersb, CD. Wattsb, A.B.A. Boxallb, R.D. DaVisb, R. ScoffmC ‘Wastewater Technology Centre, RockClilfc Research Management Inc., P.O. Box 5068, Buriingt~, ON, L7R 4L7, Gnu&~ b WRc pk Me&nenham, Henley Road, Marlow. Bucks, SL7 ZHD, UK ‘Oxford Molecular Ltd., The Magdolen Centre. Oxford Science Park, sondjbrd-on-Tkames, Oxford OX4 4GA. UK AbStlWt Municipal sludge applicationon agricultural land (land utilization) is practised widely and accounts for between 3040% of production in Canada and the UK. Land utilization is subject to public concerns over the potential for deleterious effects of organic contaminants on agriculturalproductivity and uptakeinto the foodchain. Consequently, reliable data on the concentrations of organic contaminants in sludge arerequired to assess risks associated with land use. A detailed monitoring survey has been carriedout by WTC to determine the concentrations of a range of industrial organic contaminants in 11Canadian sewage sludges and one sludge compost. Volatile, base-neutral andacid extrac- tablecontaminants seldom exceeded 5 mg kg-’ dry wt., organochlorine pesticides and polychlorinated biphenyls did not exceed 1 mg kg-’ dry wt. and toxaphene and N-nitrosodimethylamine werenot detected in the materials analyx- ed. Mean total PCDD and PCDF concentrations were 5 36 Pg kg-’ dry wt. (median 6.7 pg kg-’ dry wt.) and mean toxic equivalents were SO. 12 pg kg-’ dry wt. (median 0.02pg kg-’ dry wt.). It was concluded that in many Canadian sludges the aforementioned organic contaminants represent no signiticantrisk to agricultureand the environment. However,other organiccomaminants potentially present in sewage sludge may not be amenabk to analysis by the target compound techniques widely used. Consequently, WRc have applied a non-analytical approach to assess which contaminants mayoccurin sewage sludges andpersist in treatedsoils. Predictions of physicochemical properties using quantitive structureactivity relationships (QSARs)havebeen used to aid the screening and prioritisation of a range of highproductionvow chemicals (HPVCs)that mayentersewage treatment works.Analytical surveys for organic residues areexpensive and this type of approach mayassist in identifying further contaminants which should beanaly red in sewage sludges and treated soils. Keywordr:Organiccontaminants; Sewage sludge; VOC, Non-analyticalmethods; Ranking * Corresponding author. 004&%97/96iS15.00 0 1996 Elsevier Science B.V. All rights reserved SSDI 0048-9697(96)05040-F