EcoRecycle Victoria and
Swinburne University of Technology
Grant No 261/02/01
Technical Report on
the In-line Litter Separator
Installation and Monitoring Project
By Dr Donald I. Phillips
August 1998
Prepared for EcoRecycle Victoria
Copyright of this report is held by Swinburne University of Technology. Reproduction or transmission of any material in the report in whole or in part by any means whatsoever is expressly forbidden without the written permission of the University.
The author is a Senior Lecturer in the School of Engineering and Science
AcknowledgEments
The author wishes to acknowledge the many people and organisations that contributed to the success of the project.
In particular, thanks is given to the council of Eco Recycle Victoria and its Chief Executive Officer, Mr Ian Coles, for providing both the funding and administrative support for the project. Without this assistance it is unlikely that the In-line Litter Separator would have been developed. Certainly it would not be the commercial reality it is today.
Special thanks is owed to the Program Supervisor, Mr David Rako for his valuable and often timely assistance in ensuring the continuing progress of the project.
And thanks must also be given to the South Eastern Regional Waste Management Group and particular its Manager, Mr Martin Aylward, whose vision and persistence ensured that the early investigative work was undertaken. Mr Aylward also obtained the funding from the Resource Recovery and Recycling Council for this work and coined the name, the In-line Litter Separator.
The members of the Advisory Committee are thanked for their advice, encouragement and support throughout the two years of the project. In particular, Mr Peter Hotchins who so ably filled the role of both Secretary and Treasurer.
The eight participating Local Government municipalities and their officers are also thanked for their enthusiasum, cooperation and assistance in the installation and monitoring of the prototypes.
And thanks must be given to the participating manufacturers, SVC Products Pty Ltd and CSR Ltd for manufacturing the prototypes and to Mr Bruce Bowditch, Managing Director of SVC and Mr Keith Caporn, National Product Development Manager of CSR, for their many practical suggestions to improve the prototypes.
In particular, special votes of thanks are due to Mr Philip Watson of the School of Civil Engineering and Building at Swinburne University, who constructed and installed the laboratory models and supported the data collection, and to Mr Stephen Woods who gathered and analysed the data essential for prototype evaluation.
The evolvement of the ILLS from a simple laboratory model to a commercial reality in only two years is a truly remarkable achievement and a tribute to the efforts of these many people.
The In-line Litter Separator promises to make a valuable contribution to the reduction of unsightly litter on the banks and shores of the communities waterways and beaches and so enhance the communities enjoyment of these irreplaceable assets.
Table of Contents
Section Page
TITLE PAGE1
ACKNOWLEGEMENTS2
TABLE OF CONTENTS3
LIST OF FIGURES6
LIST OF TABLES7
LIST OF PLATES8
1Introduction 9
2Background 11
3Administration of project 12
3.1Partnership members
3.2Advisory committee
3.3Time frame of implementation
3.4Grant payments
3.5Liaison with Local Government
3.6Liaison with Industry
3.7Manager
4The In-line Litter separator 15
4.1Mode of operation
4.2ILLS features
5Physical modelling 18
5.1General considerations
5.2Non-dimensional modelling
5.3Minimum dimensions
6GENERAL DESIGN CRITERIA 22
7NUMERICAL MODELLING 24
7.1Assumptions
7.2Frequency of boom lift
7.3Boom mass and lift frequency
7.4Boom dimensions
8LABORATORY STUDIES 28
8.1Introduction
8.2Derivation of a boom-weir equation from
laboratory tests
8.3Boom SG in terms of physical measuremets
9HYDROLOGICAL MODELLING 33
10INDICATIVE CAPTURE EFFICIENCIES 37
11DESIGN OF RETURN CHANNEL 35
12INSTALLATION, TESTING AND ANALYSES OF
FIRST GENERATION PROTOTYPES 44
12.1Introduction
12.2Proposed testing procedure
12.3Capture efficiency determination
12.4Field studies
12.4.1Toombah St ILLS, City of Monash
12.4.2Damper Ck ILLS, City of Monash
12.4.3Lygon St ILLS, City of Melbourne
12.4.4Yuile St ILLs, City of Boroondara
12.4.5Luck St ILLS, City of Nillumbik
12.5Discussion
13DERIVATION OF THE DIMENSIONAL
RATING NUMBER 50
13.1Introduction
13.2Derivation of relationship between peak
runoff and ILLS dimensions
13.3Derivation of relationship between peak
run-off and catchment area for Melbourne
14EVALUATION OF THE MELBOURNE DRN 54
14.1Introduction
14.2Prototype performance rating
14.3DRN’s of first generation ILLS
14.4Summary
15INSTALLATION, TESTING AND ANALYSES OF
SECOND GENERATION PROTOTYPES 56
15.1Introduction
15.2Prototype testing
15.2.1Youth St ILLS, City of Nillumbik
15.2.2Broughton St ILLS City of Frankston
15.2.3The Avenue ILLS, City of Kingston
15.2.4O’Grady St ILLS, City of Port Philip
15.2.5Lonsdale St ILLS, City of Greater Dandenong
15.3Summary of second generation monitoring
16REVIEW OF PROJECT 63
17CONCLUSIONS 65
List of Figures
Figure Page
4.1Plan view of internal arrangement of ILLS 15
4.2ILLS in left-hand mode 16
5.1Side elevation of ILLS 19
7.1End and plan views of boom 27
8.1Graph of weir flow and pipe flow from laboratory tests 29
8.2Graph of peak weir flows for different boom SG’s 30
8.3Maximum flow depths for various ARI rain storms 33
9.1Adopted weir verses pipe flow relationship 34
9.2Simplified hydrographs for hydrological modelling 35
11.1Return channel at maximum weir flow 38
List of Tables
Table Page
5.1Ratio of O.D. to nominal diameter (Humes catalogue)20
5.2Minimum ILLS dimensions21
7.1Storm intensities for various ARI’s and durations (Melbourne)24
7.2Ratios of Qx / Q5 for various ARI’s and durations (Melbourne)25
7.3Ratios of d / D for various ARI’s and durations (Melbourne)25
7.4Frequency per annum of varying pipe flow depths25
7.5Mass of boom and lifting frequency per pipe diameter26
7.6Dimensions of boom per nominal pipe diameter27
8.1Experimental pipe and weir flows29
10.1Indicative capture efficiencies for targeted litter items37
11.2End widths of return channel; So = 1.73%39
12.1First generation prototype data, in order of instalation44
12.2Litter capture efficiencies; Toombah St pilot program45
12.3Gross pollutants; Toombah St pilot program46
12.4Gross pollutants; Lygon St ILLS48
12.5Gross pollutants; Yuile St ILLS48
13.1Five year ARI intensity and discharge ratios for Melbourne52
15.1Second generation prototype data in order of installation57
15.2Litter capture efficiencies, Youth St ILLS58
15.3Gross pollutants, Youth St ILLS58
15.4Gross pollutants, The Avenue ILLS60
15.5Litter capture efficiencies, O’Grady St ILLS61
15.6Gross pollutants, O’Grady St ILLS61
LIST OF PLATES
Plate Page
1An In-line Litter Separator ready for delivery10
5.1Laboratory model with boom at rest17
5.2Laboratory model with boom at maximum lift21
6Installation of ILLS, City of Kingston23
7Wedge boom27
8Laboratory model showing final configuration33
11Triangular return channel and weir40
12.1Location of ILLS prototypes41
12.2Installing the Toombah St ILLS45
12.3Pumping out the Lygon St ILLS46
12.4Sorting material from Lygon St ILLS47
12.5Boom lifting during high flow, Youth St ILLS49
13Test items in Toombah St ILLS53
15.1Youth St ILLS prior to first pump-out58
15.2Pumping-out The Avenue ILLS59
15.3Installing the O’Grady St ILLS61
15.4Installing the Lonsdale St ILLS62
1. Introduction
The In-line Litter Separator is a patented gross pollutant trap developed in response to the communities concern with unsightly litter on the banks of urban streams and the beaches of our bays.
Litter is categorised as a gross or “visible” pollutant, a term usually applied to pollutants greater than 5mm in size. Litter detracts from the public’s enjoyment of urban streams and beaches while syringes, frequently present in stranded litter, are a health hazard. In the aquatic environment, litter smothers plants and chokes animals.
The source of this litter is primarily shopping centres and fast food outlets. Wind and rain carry the litter into the stormwater system and is conveyed to the streams and bays during storms. The floating fraction of this material either snags on vegetation on river banks during high flows or, on reaching the bays, is eventually blown shorewards by prevailing winds to strand on foreshores.
The litter problem has been exacerbated in recent years following the increase in non-biodegradable food and beverage packaging, especially plastics and metals, leading to their accumulation in the environment.
Gross pollutant traps (GPT’s) usually consist of screens or wire baskets installed at the outlets of piped drainage systems or in side entry pits on roadways. They have many inherent drawbacks including a propensity to blockage, limited storage capacity, loss of trapped material during high flows, frequent and expensive cleaning, flow bypass at moderate inflows, high energy losses, and are ineffective in removing oil and grit.
GPT’s located at the downstream end of piped drainage systems are capital intensive while those in side entry pits on roadways, at the top of catchments are labour intensive. As neither type was satisfactory, research was directed at employing different approaches that overcame these problems.
The then Waste Management Council of Victoria, now EcoRecycle Victoria, in response to public concerns, awarded a grant to Swinburne University of Technology to develop a promising new GPT known as the In-line Litter Separator (ILLS).
The ILLS is essentially a trap for floating litter but also removes a high proportion of all gross pollutants. The development program involved the construction of ten prototypes to be installed downstream of shopping centres in the Melbourne metropolitan area and monitored over a period of twelve months.
It was proposed to test and monitor each prototype prior to manufacturing the next, so that following prototypes would incorporate design and manufacturing improvements gained from experience with the proceeding units.
The test program assessed the trapping efficiency of the unit for targeted litter items employing a deductive approach. The target items were selected from a previous study into the composition of litter entering the urban drainage system and from litter present in the initial pump-out of a new unit. The representative sample of target items was introduced into the drainage system upstream of prototypes.
By means of the monitoring and testing program, together with concurrent laboratory and theoretical studies, the trapping efficiency and general performance of the subsequent prototypes improved.
Studies showed that theoretically, very high trapping efficiencies were possible. Hence a principal aim of the program was to optimize the trapping efficiency of the ILLS through employment of best practice design and manufacturing procedures.
2. Background
In June 1995, the School of Civil Engineering and Building at Swinburne University of Technology commenced studies on litter in urban stormwater systems under grants from the South East Regional Waste Management Group and the Resource Recovery and Recycling Council of Victoria.
The studies aimed at gaining an understanding of the sources, quantities, composition and transport mechanisms of litter entering the drainage system together with an examination of methods for its removal.
The field data was obtained from the litter captured in baskets placed in side entry pits in three shopping centres in the City of Glen Eira. The data gathering was conducted by Mr Matthew Hall, as part of a Master of Engineering by Research program, between August 1996 and August 1997. The results provided valuable information for the design of the first prototypes.
Laboratory experiments culminated in a model device incorporating a floating boom that deflected entrained material from flowing water. The University patented the device, known as the In-line Litter Separator, in July 1995. The name was proposed by Mr Martin Aylward, Manager of the South East Regional Waste Management Group.
With the assistance of the City of Glen Eira and SVC Products Pty Ltd, the first ILLS prototype was installed in Bendigo Avenue, Bentleigh, in August 1995, in a pipeline draining approximately four hectares of the Centre Road Shopping Centre.
Subsequent monitoring of the device showed that it had considerable potential, but would require extensive development before becoming a commercial proposition. Further laboratory work was undertaken to examine ways of overcoming the many problems evident in the prototype.
By April 1996 significant progress had been achieved and the Waste Management Council of Victoria offered Swinburne University a grant to develop the ILLS to a commercially viable product.
An agreement was signed in August 1996 to design, install and monitor ten prototypes in a two-year program under a $100,000 grant.
3. Administration of project
3.1Introduction
The project entailed the design, manufacture, installation and testing of ten (10) prototypes sequentially over a period of two years. The progress of the project was to be reported at two-monthly intervals to the Waste Management Council of Victoria, with a final report to be submitted by the 20 August 1998.
During the project the Waste Management Council of Victoria and the Resource Recovery and Recycling Council amalgamated to form EcoRecycle Victoria that assumed the responsibility for the project.
3.2Partnership members
The project was a partnership between the following state and local government agencies, industry and university viz:
The Waste Management Council of Victoria
City of Boroondara
City of Frankston
City of Greater Dandenong
City of Kingston
City of Melbourne
City of Monash
City of Nillumbik
City of Port Phillip
SVC Products Pty Ltd
CSR Ltd
Swinburne University of Technology
3.3Advisory Committee
The composition of the committee was specified in the Agreement and the members appointed by the Chair and Project Manager, Dr Don Phillips, viz:
Mr Martin Aylward, Manager, South Eastern Regional Waste Management Group; Mr Peter Hotchins, Finance Manager, Swinburne University of Technology;
Mr Bruce Sandie, Head of School of Civil Engineering;
Mr Bruce Bowditch, Managing Director, SVC Products Pty Ltd;
Mr Keith Caporn, National Product Development Manager, CSR Construction Materials.
Mr David Rako, Program Supervisor, Waste Management Council of Victoria was ex-officio.
The Committee met at two-monthly intervals to review the progress of the project and to advise the Project Manager on problems that emerged during the project. Changes to its composition occurred with the inclusion of Mr Stephen Woods in April 1997 and Mr Kerry McManus in July 1997, replacing Mr Bruce Sandie, who retired from Swinburne. Mr Bowditch resigned from the Committee in November 1997, following the withdrawal of SVC from the project.
3.4Time frame of implementation
The two-year project was to consist of twelve months of prototype installation followed by twelve months of prototype testing and monitoring. However due to the severe drought of 1997-8, compounded by design, manufacturing and installation delays, the final prototype was not installed until April 1998.
To enable adequate monitoring and data collection from the last prototypes, EcoRecycle were requested to approve the extension of the program to November 1998, when the grant monies would be expended.
3.5Grant payments
The grant of $100,000 was to be provided by the Waste Management Council of Victoria in four payments of $35,000, $35,000, $20,000 and $10,000. The first payment was to be provided on signing of the Agreement by Swinburne and subsequent payments on provision of a statement of bona fide expenditure of the previous payment.
3.6Liaison with Local government
WMC invited expressions of interest from local government to participate in the program and selected eight of the sixteen applications received. The eight councils were awarded grants towards the purchase and installation of the prototypes.
The grant was conditional on the council supporting the twelve month monitoring and testing phase. The first grants were for $6,000 but this was increased to $10,000 for later prototypes as experience showed that larger units were required.
The Manager liased with the chosen councils to assist in site selection, design,
installation, monitoring and testing aspects.
3.7Liaison with industry
Because of the newness of the ILLS device, difficulties and delays were anticipated in addressing problems in its production. Therefore to enable the prototypes to be supplied within the time-span, two manufacturers, SVC Products Pty Ltd and CSR Ltd, were invited by the Manager to participate in the program.
3.8Manager
The responsibilities of the Manager included arranging Advisory Committee meetings at two monthly intervals; written reports to the project supervisor on the progress of the project every two months; financial statements detailing all expenditures incurred and liaison with local government and manufacturers.
4. The In-line Litter Separator
4.1 Mode of operation
By June 1995, laboratory research had focussed on the concept of a floating boom to skim litter from stormwater. This had additional advantages as it not only skimmed off buoyant litter at all depths of flow, but also deflected submerged materials when at rest on the floor of the separator chamber, during low to moderate flows. In addition it lifted clear when the pipe flowed full, permitting an unobstructed flow passage.
To deflect these materials from the flow, the boom was angled towards an adjacent holding chamber. This presented practical difficulties and a rounded tapered boom was tested, evolving to the tapered wedge shape shown in Figure 4.1 below.
The floating materials were retained in the holding chamber by a baffle on the outlet port while the submerged material sank to the floor of the chamber. This floor was set below the separator chamber.
However as the design criteria included fail-safe performance and ease of maintenance, a baffled weir was developed which conferred the added bonus of retaining oils and grease. The final outlet system consisted of the baffle, a notched weir and a return channel to the outlet port as shown in Figure 4.1 below.
Figure 4.1 Plan view of internal arrangement of ILLS
The weir’s function was to distribute the flow under the baffle during high flows to reduce the likelihood of suspended materials being carried out. To achieve this the crest was set above the invert level of the pipeline and vee-notches cut to the invert level of the pipeline to permit the passage of trickle flows. The whole assembly could be fabricated from a single sheet of galvanised steel. A secondaryfunction of the weiristo ensure that the flow entering the unit is sub-critical as the boom lifts. The theory is developed in Section 11.
The general arrangement of the ILLS is shown in Figure 4.2, below.