CSO Research

National CSO Test Facility Wigan WWTW: CSO Screen Efficiency 1997 - 2005

Reference: 06/WW/08/14
ISBN: 1 84057 404 6
Published Date: 15/05/2006

The report describes a comparative performance analysis of over 30 proprietary CSO / Overflow Screens tested in either a side weir CSO chamber, an extended stilling pond chamber or as stand-alone devices at the National CSO Test Facility, Wigan Wastewater Treatment Works.

Performance evaluations were made to assess the process efficiency of each screen, expressed as 'screenings retention value', at a series of inflow magnitudes and ratios of continuation flow to inflow.

The report gives a  technical description of each screen together with full test results and offers a comparison of equipment performance covering the various generic types of CSO screen currently available.

Price: £32  

Characteristics of Sewage Particles

Reference: 01/WW/08/10
ISBN: 1 84057 230 2
Published Date: 17/04/2002

The report combines the findings of two projects sponsored by UKWIR's CSO Research Group. One, by Sheffield Hallam University, carried out an evaluation process to categorise the different particulates in raw sewage and produce distributions of terminal velocities for each category. The second, by the University of Sheffield, evaluated the terminal velocity characteristics of the sewage particulates which enter the National CSO Test Facility at Wigan Wastewater Treatment Works, and monitored changes which occur due to the time of day and at different flowrates. The utilisation of the results of this project will increase confidence in the assessment of the separation efficiency of CSO chambers and unscreened novel devices. When implemented within design software, this will enable wastewater operators to adopt unscreened solutions, where appropriate, to minimise costs whilst satisfying aesthetic quality aspects of UCSO improvements.

Price: £16  

Intermittent Discharges - Environmental Review and Treatment Solutions

Reference: 02/WW/08/12
ISBN: 1 84057 256 6
Published Date: 17/04/2002

Research was carried out into unconventional treatment options for Combined Sewer Overflows (CSOs) to find potential compact, reliable and cost-effective solutions to improve the quality of intermittent discharges. Future standards for discharges may dictate that storage or increased sewer capacity will not be satisfactory. No single wastewater treatment process is sufficient for all eventualities, but twelve processes were deemed technically and economically suitable for further consideration. The disadvantages and advantages of each of these processes in relation to treatment at CSOs were investigated. Most favoured processes are: ballasted lamella plate sedimentation for a large urban CSO; reed bed treatment for a small rural CSO; and chemical pre-treatment followed by UV disinfection for a CSO discharging into bathing waters. Pilot plant testing should be carried out in each case.

Price: £22