Institution of Municipal Engineering of Southern Africa IMESA Conference 2002 ‘Yesterday, Today – The Key to a Sustainable Future’ East London, South Africa, 23 – 25 October 2002 ISBN: 0-9584534-3-8 Produced by: Document Transformation Technologies

EXTENDED LIFE FOR LANDFILL SITE: AN ENGINEERING SOLUTION

van Huyssteen, J.A.1 and van Wageningen, C.L.2

1MBB Consulting Engineers, P O Box 3011, Matieland 7602

2Breede River Winelands Municipality, P O Box 52, Robertson, 6705

SYNOPSIS The existing waste site serving the municipal areas of Robertson and McGregor (total population < 27 000) is to be closed and rehabilitated. A new site is to be identified that will comply with the Minimum Requirements of the Department of Water Affairs and Forestry. The identification and registration of a new waste site is a lengthy process and an urgent course of action had to be decided on. MBB Consulting Engineers were appointed to submit proposals to avert a potential financial and environmental disaster. A pre-feasibility study showed that the life of the existing site could be extended considerably through waste minimisation by composting of garden refuse. Tenders were called for composting plant and equipment and the operation and maintenance of the composting facility. The composting facility has now been in operation for more than two years and historical data shows that although mainly garden wastes are being composted, the average saving in landfill air space over this period was approximately 31%. This in itself translates into considerable monetary saving. A second contract was subsequently awarded for the operation until closure of the landfill site and both of these projects are presented as an example of the role engineering has to play in environmental concerns. SHORT BACKGROUND In the year 1990 Robertson Municipality was due to inter alia political factors forced to stop dumping refuse at their existing Landfill site. The method that was used was to burn all the refuse everyday. Due to the fact that most garden refuse was still green, this resulted in a cloud of smoke hanging over the area which became an unacceptable situation. ADDRESSING THE PROBLEM Although historically the handling of refuse was dealt with by the Health Department, this suddenly become the problem of the Town Engineer. It was of course necessary to act immediately to handle the ever-growing heap of refuse. The first site that was decided on was unacceptable to public and another site had to be found. With the help from Walter Tworeck from Department of Water Affairs and Forestry (DWAF) a new site was found which was above the 1:50 year floodline and below the sewerage works. The necessary permit application which at that stage was quite a lot easier than nowadays, was forwarded to DWAF in September 1990. Our crisis was eluded and everything was in order except for the normal day-to-day problems.

After approximately six years it became evident that this site was filling-up at a rate far greater than was anticipated. Already in 1992 it was established that approximately 50% of the refuse stream came from garden refuse. It was decided to divert the stream of garden refuse from municipal source to some other place where it could be burnt in future. Permission was obtained from DWAF to raise the height with another 2 meters. This gave us some time to find a new site again. THE WAY AHEAD Approximately this time I got involved in the Waste Minimization Club in Cape Town. This gave me the vision to go “green” with our total refuse stream which included recycling, composting, etc. In the meantime we decided that the garden refuse be dealt with on the refuse site again and not be burnt. During 1997 we had various meetings with MBB Consulting Engineers and various proposals with regard to what should be done when and how were put before Council. On the 24th February 1998 Council decided inter alia that MBB Consulting Engineers must put forward a written proposal with costs for providing consulting engineers services with respect to the establishment of a new refuse site taking into account the possibilities of waste minimization by composting and recycling. On 26th February 1998 Council decided that tenders should be invited for the above. Although there were lengthy arguments with respect to the expediency of this resolution I drew up the necessary documents and tenders were invited. Of course the most expensive tender received was that of MBB – not because they are the most expensive firm, but mainly because they offered exactly what the tender stipulated. After more lengthy discussions Council finally decided on the 13th August 1998 to accept the tender of MBB Consulting Engineers and we were on our way. Being the most bulky substance in our refuse stream, it was decided to start with the composting of all garden refuse. This we anticipated, would provide the biggest saving in air space in the existing landfill site. COMPOSTING FACILITY Waste collection records kept by the Municipality, were used to plot the graph shown in Figure 1. The information shown is estimated bulk volume, since it is based on recorded loads of various types of collection vehicles. This graph confirmed earlier observarions made by the client that between 40 – 50 % of the average daily loads transported to the landfill site are comprised of garden refuse. An application submitted to the MIIU for a grant funding for technical assistance, was successful and this grant covered 70 % of the professional fees in respect of the implementation of the composting project. Tenders were called for two options. The first option was for the supply of labour and the management of the composting facility, where the Council would supply and maintain all the plant and equipment. The second option was for a full operating contract, where the contractor would also supply and maintain his own plant and equipment.

ROBERTSON LANDFILLUNCOMPACTED WASTE VOLUMES (ESTIMATED)

0

500

1000

1500

2000

2500

3000

Jan'95 Jun'95 Nov'95 Apr'96 Sep'96 Feb'97 Jul'97 Dec'97 May'98

MONTH

VO

LU

ME

(m³)

MUNICIPAL SOLID WASTE GARDEN WASTE

Figure 1: Robertson Landfill – Uncompacted waste volumes (estimated)

It was finally decided to accept a tender for the management of the composting facility (labour and management) and a separate tender for the supply of plant and equipment. These tenders were accepted during November 1999 and December 1999 respectively. Since delivery of equipment was not expected before February 2000, the contractor appointed for the management of the facility started with traffic control only at the landfill site. All loads arriving at the landfill site were inspected and clean garden refuse loads were diverted to the composting facility adjacent to the landfill site, while all materials not suitable for composting were directed to the landfill site. Initially the contractor received mixed loads where inorganic material was covered by garden refuse, not noticeable to the traffic controller. In such cases the inorganic material was removed by hand before the organic material could be stockpiled. The inorganic material then had to be carted to the landfill site. However, the public soon adapted to the idea of the composting facility, with the help of articles in the local newspaper and marketing by both the municipality and the contractor. Once composting actually started, the public became even more interested and very little inorganic material was found in the garden refuse loads received at the composting facility. The contractor also made an effort to arrange the logistics at the compost facility as user friendly as possible. The process decided on for the preparation of compost was the Controlled Microbial Composting (CMC) process, which was developed in Austria during the mid 1970’s and is today widely used in Europe. The successful contractor attended a full CMC training course.

Figure 2: Robertson composting facility The CMC process differs from conventional composting processes in the following way:

• CMC compost is ready for use in six to eight weeks; • controlled breakdown and built-up phases prevent anaerobic decomposition and thus annoying

odours; • ground water leaching and rainwater infiltration is prevented by covering windrows with gas

permeable yet water repellent geo-textile; • through inoculation of windrows with CMC starter and with Effective Microbes during the

process, the raw materials are broken down and converted to nutrient rich humus in an optimal way;

• quality of the end product is guaranteed through simple monitoring methods. One of the main reasons for the choice of the composting process was the fact that the CMC compost is widely used as organic fertiliser, which would assist in the marketing of the final product. During the first year the contractor concentrated on the preparation of two compost types i.e.:

• Class I compost being Effective Microbe enriched compost and suitable for use as organic fertiliser in organic agriculture in compliance with USDA/SGS requirements

• Class II compost, which could be registered for use as fertiliser in terms of Act 36 of 1947 Once the facility was in full operation, the contractor started making compost windrows using dried sewage sludge in lieu of animal manure. The effectiveness of the chosen process was substantiated by the fact that no odour nuisance was experienced. This final product was marketed as class III compost. Following the success with sewage sludge, abattoir wastes in the form of paunch and blood, was added to the compost windrows as substitute to the animal manure, with the same results. Operation of the facility is fairly simple and the minimum equipment requirements are as follows:

• Windrow turner • Tractor fitted with creeper gear for pulling windrow turner • Tractor fitted with front end loader assembly • Wood chipper, PTO driven • Three-way tip trailer • Temperature and CO2 monitoring equipment

The total cost (1999 prices) of the abovementioned equipment was approximately R540 000 (VAT included). The tractor fitted with the creeper gear is mainly used for the operation of the windrow turner, while the other tractor is used for chipping and windrow construction. Some of the equipment in use at the Robertson composting facility are shown in the following photos:

Figure 3: Tractor pulled windrow turner in operation

Figure 4: Windrow turner profile and rotor

Figure 5: Wood chipper in operation The sale of compost was initially restricted to residents of Robertson and nearby McGregor, but was gradually extended to the farming community. Marketing to date has mainly been through word of mouth. Composting of the garden refuse provided the municipality with the much needed extension of the life of the existing landfill site. It also assists in the disposal of problem wastes such as sewage sludge as well as paunches and blood from the abattoir. The capacity of the landfill site was monitored by doing regular surveys of the site and from these surveys it was established that the average saving of air space as result of composting was of the order of 31 %. Before the composting operation was started, numerous complaints were lodged by the ARC Research Farm neighbouring the landfill site. The composting contractor was tasked with the responsibility to collect wind blown litter from the land surrounding the landfill site, and in this manner the problem of wind blown litter was eradicated. OPERATION AND CLOSURE OF LANDFILL SITE Since the Robertson landfill site was due for closure within a couple of months, it was recommended to Council, and accepted as such, that tenders be called for the operation of the landfill site until closure. It was anticipated that the proper operation of the landfill site would further extend the life of the landfill as result of proper compaction A closure design was submitted to DWAF for approval. The design comprised a clay clapping layer of 200 mm thick and 150 mm top soil, including provision for stormwater handling and subsoil leachate monitoring Tenders were thus called for the operation of the landfill site until closure in accordance with the DWAF minimum requirements and the closure permit. A tender was accepted and work started in June 2001. It was specified in the contract that rehabilitation of the sides of the “dump” should commence immediately to limit wind blown littering of the surrounding areas. Figures 6 show the front wall of the “dump” site before the contract started.

Figure 6: Front wall of “dump” site Figure 7 shown the same wall one month after work started. By this time the sides were trimmed to the correct slopes and work started on the clay capping.

Figure 7: Front wall of landfill after one month The access on to the landfill was improved simultaneously as can be seen from the following photographs.

Figure 8: Access road to “dump”

Figure 9: Access road on to landfill one month later Nex the top of the “dump” was reshaped, compacted and covered to suit the closure design profile and landfilling were done in smaller cells which could be compacted properly and covered at the end of the day. Figures 10 and 11 show what the top of the “dump” looked like before the contract started.

Figure 10: Top of “dump”

Figure 11: Landfill compactor operating on dump A landfill compactor was used on the “dump” to compact refuse but the effort was ineffective since no cover material was added. Figure 12 show the dramatic improvement, which took place after the contract started.

Figure 12: Top of landfill one month after The landfill operating and closure contract has now been running for more than one year and not only is all that remained from the once unsightly dump just a green “hill” as can be seen from Figure 13, but a further valuable saving in air space was affected by proper compaction of the daily waste cells. The heavy plant used on the landfill for rehabilitation works, compacted the lower lying refuse layers which contributed to a further landfill air space saving.

Figure 13: View of landfill from Robertson/McGregor Raod CONCLUSION The composting facility has now been in operation for 30 months. Based on data kept by the contractor it is calculated that the nett average saving in landfill air space over this period was 31 % (compacted). The life of the landfill was thus extended by approximately 10 months, gaining valuable time before waste will have to be transported to Ashton, which in monetary terms is a considerable saving.

The composting facility also allows for an environment friendly and responsible way to dispose of abattoir waste such as paunches and dried blood as well as dried sludge from the municipal wastewater treatment works. The contractor successfully included these wastes in compost classified as Grade III compost. The enthusiastic approach of all the role players made this waste minimisation project a success story and also helped to remove some of the misconceptions that exist with regards to composting as a cost effective way of waste reduction. Although it does not appear so at first glance, a private contractor can to a certain extend do the operation of a landfill more cost effectively than a local authority, since it is not the core function of the latter. The contract for the operation and closing of the landfill site also helped to show the public the difference between a properly operated sanitary landfill and a dump site, which would to a great extent help to allay public opposition to the regional landfill site identification and registration process. The Robertson landfill is a great example of the role engineering has to play in environmental concerns.

EXTENDED LIFE FOR LANDFILL SITE: AN ENGINEERING SOLUTION

van Huyssteen, J.A.1 and van Wageningen, C.L.2

1MBB Consulting Engineers, P O Box 3011, Matieland 7602

2Breede River Winelands Municipality, P O Box 52, Robertson, 6705

CURRICULUM VITAE COR VAN WAGENINGEN • Matriculated at Jan van Riebeeck High School, 1964. • Obtained the Higher National Diploma for Technicians (Civil Engineering) end of 1969. • Started working for WJM Construction on the Durbanville Freeway project – 1970. Went to Concor

Grinaker Construction on the Voëlvlei Water Purification plant in 1971. • Then did consulting work with Truter & Partners in Stellenbosch during 1972 and 1973. • Joined Worcester Municipality in 1974 till 1983. • Appointed Town Engineer at Robertson Municipality 1983. • After the amalgamation of municipalities was appointed as Head of Civil Engineering Services in

December 2001 • Member of IMESA • Member of SAICE • Married to Louise for more than 30 year and have two sons. • Hobbies are hiking, cycling, caravanning and watching F1 Grand Prix on television. JOHAN VAN HUYSSTEEN • Matriculated at Diamantveld High School, Kimberley in 1965. • Graduated from University of Stellenbosch with B.Sc B.Eng (Civil), 1971. • Started working for Spoornet (SAR & H) as assistant Engineer in 1972. • Joined Van Wyk & Louw (now Africon) as Resident Engineer on Construction projects towards the

end of 1973 and remained on site until mid 1975. • Worked as design engineer for Meiring & Barnard from 1975. • Became Associate in 1978 and Direcor of Meiring & Barnard in 1981. • Continued as director of Wates Meiring & Barnard after amalgamation of Wates & Wagner and

Meiring & Barnard until beginning of 1993. • Started farming in Riversdale area during 1993. • Joined MBB Consulting Engineers as Civil engineer mid 1996. • Became director of MBB mid 2002. • Registered as Professional Engineer. • Member of the South African Institute of Civil Engineers. • Member of the Institute of Waste Management of Southern Africa. • Married to Elmarie and has one daughter. • Enjoy cycling and participate in as many “Fun Rides” as possible.