RFI - Attachment F - Engineering Report

Evaluation of Gully Pit Inlet Litter Control Systems– Brisbane City Council and Gold Coast City Council

                1. INTRODUCTION AND PREAMBLE




                Brisbane City Council engaged the Urban Water Resources Centre to
                undertake a hydraulic evaluation of various litter control systems for a
                typical Lip-in-Line Gully Pit.


                Hydraulic testing was undertaken using a short (2400mm) lintel inlet
                with the roll top kerb and channel and flows ranging from 0L/sec to
                340L/sec at longitudinal grades of 1%, 4% and 12%. Testing was
                undertaken with the following gully pit litter control systems:


                     •   A 36mm diameter horizontal bar placed across the mid point of
                         inlet opening (as shown in Appendix A),
                     •   meshed pit insert,
                     •   a tray basket (900x500x150), and
                     •   standard Enviropod trash basket.


                Testing was carried out using the full-size road test rig at the University
                of South Australia. A standard litter sample was developed and used for
                the evaluation. Litter comprised of 80% organics (leaves) and 20% paper,
                plastic and sediment. A modified litter sample (Appendix B) was used
                for the evaluation of the horizontal bar system. It contained a greater
                proportion of larger litter, including plastic food and drink containers,
                plastic bags and aluminium cans.


                Briefly, the aim of the evaluation was to:
                     •   Determine the litter capture performance characteristics of each
                         system, and
                     •   determine the effect that each litter control system has on the inlet
                         hydraulic capture performance.




                Urban Water Resources Centre               4             University of South Australia