SEWER SEDIMENTS - PREPARATION METHODS FOR ENUMERATING BACTERIA

In the UK, the Urban Pollution Management programme has contributed to extensive international research concerning solids associated with ur ban drainage systems. Since 1986, as part of the UPM programme, resear ch undertaken at the Wastewater Technology Centre, University of Abert ay Dundee, has focused primarily upon the characteristics and movement of solids and associated pollutants in combined sewer systems. These investigations have considered the behaviour of sediments and their at tached pollutants during dry weather and storm flow conditions, and al so the degree of pollutants associated with, and released from sewer s ediments during periods of increasing sediment bed shear stresses. Dat a collection and sample analysis were driven by requirements specified for the development of a United Kingdom sewer flow model termed ''MOS QITO'', with the basic chemical parameters ie; COD, BOD and ammonia, o f sewage and sewer sediments. A data collection programme is described which assesses the feasibility of using combined sewer sediment prepa ration protocols, normally used for these chemical analyses, to enumer ate bacterial indicator organisms present in deposited sediments; The data were analysed to investigate whether the methods used were precis e in terms of repeatability, prior to more extensive studies being und ertaken to provide sewer sediment data for bacterial numbers. Copyrigh t (C) 1996 IAWQ.