Pollutional aspects of gross solids and their interaction with sewer sediments

This paper describes a study programme underway in the upper Perth Road catchment in Dundee to estimate the effect of gross solids and their interaction with the sediment found within a combined sewer network. Gross solids have been collected at three different sites in the study catchment, near its head, at the catchment outfall and at an intermediate site. In conjunction with the study of gross solids, sewer sediment samples were collected and analysed to determine both their chemical and physical characteristics. The study also includes flow sampling (both dry and storm) and gully discharge monitoring. The pool of pollutants information thus collected includes surface derived, foul flow and gross solids pollutant characteristics. The objective of the study programme is to analyse the contribution made from the various inputs and to produce a budget of pollutants within the study sewer system. A description of the field and laboratory work undertaken in the study is described, together with a preliminary assessment of the pollutants budget technique.