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Landfill 2011 Seminar, 18 - 20 October, Durban, KwaZulu-Natal PDF

180 Pages·2011·11.52 MB·English
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Preview Landfill 2011 Seminar, 18 - 20 October, Durban, KwaZulu-Natal

Keynote Address: Towards Appropriate Contaminant Containment Standards K Legge ............................................................................................................................................. Not available Composition of Waste Landfilled at Metropolitan Landfills and the Impact of the New Draft Waste Regulations C C Wise, R C Emery and J A Coetzee ............................................................................................................... 1 An Overview of ENER-G Systems Experience with Landfill Gas Utilisation Projects in South Africa D Cornish ............................................................................................................................................................. 11 Climatic Influences on Landfill Gas Extraction, with a Unique Comparison of Typical Performance between Landfills Located in the Highveld and KZN Coastal Regions B J Barratt, B L Jewaskiewitz and B L Mills ........................................................................................................ 16 Buffer Zones: The Long Term Interface L Moodley, R Winn and J Parkin ........................................................................................................................ 24 Asphalt Liners in Landfill Construction T Egloffstein and G Burkhardt ............................................................................................................................ 34 Landfill Gas Extraction Schemes - A Contractor's Viewpoint J Butt ................................................................................................................................................................... 43 Drainage Sand Bulk Sampling a New Lined Residue Disposal Facility I Nyirenda and C van Renssen .......................................................................................................................... 55 Geosynthetic Clay Liners (GCLs) – The Effects of Peel Strength on Performance C MacKenzie and N du Toit ................................................................................................................................ 64 Addressing an Integrated Approach to the use of Alternative Technologies as an Economically Viable Alternative to Landfill C Whyte .............................................................................................................................................................. 73 Denitrification of Treated Landfill Leachate using MBT Waste as a Carbon Source: The Bisasar Rd Test Cells Z Hussain, N Sawyerr and C Trois .................................................................................................... Not available Why Spend Money on Independent CQA Services during the Installation of Geosynthetic Lining Systems? B L Mills and B L Jewaskiewitz ........................................................................................................................... 83 Economic Comparison of Landfilling with and without Anaerobic Pre-Treatment G Burkhardt and T Egloffstein ............................................................................................................................ 94 Landfill Leachate Treatability L J Strachan, H D Robinson and L R Gravelet-Blondin ................................................................................... 104 Behaviour of Baling-Wrapping MSW Landfill Application in Spain J M Baldasano ................................................................................................................................................... 114 GCLs: The Buffelsdraai Landfill Experience G J Payne .......................................................................................................................................... Not available Design and Construction of a Deep Upstream Groundwater Cut-off Trench J Shamrock, J Glendinning, J Mzisa and H Janse van Rensburg .................................................... Abstract only eThekwini Municipality: Electron Road Waste Management Facility Presentation C Wise ............................................................................................................................................... Not available Mechanical Biological Treatment (MBT) Presentation R Lombard ......................................................................................................................................... Not available Slope Stability of Liners and Covers Workshop R Thiel ................................................................................................................................................ Presentation A Sustainable Mineral Barrier Option M Naismith, E Timmermans and H Mulleneers ............................................................................................... 170 Proceedings of the LANDFILL 2011 Seminar, “Waste Management Facilities – The New Order” 18 – 20 October 2011 Proceedings ISBN Number: 978-1-920017-52-1 Durban, South Africa Produced by: Document Transformation Technologies cc DAY 3 : Thursday DAY 2 : Wednesday DAY 1 : Tuesday 20 October 2011 19 October 2011 18 October 2011 Denitrification of treated landfill leachate using MBT waste as a carbon source: The Bisasar Rd Test Cells Registration (Z Hussain, N Sawyerr and Dr C Trois) Tea Why Spend Money on Independent CQA Services Keynote Address: Towards During the Installation of Geosynthetic Lining Systems? (BL Mills and BL Jewaskiewitz) Appropriate Contaminant Containment Standards Kelvin Legge Composition of Waste Landfilled at Economic Comparison of Landfilling with and without Metropolitan Landfills and the Impact o Anaerobic Pre-Treatment the New Draft Waste Regulations (G Burkhardt and Dr T Egloffstein) (CC Wise, RC Emery and JA Coetzee) An Overview of ENER-G Systems Experience with Landfill Gas Utilisation Tea Tea Projects in South Africa (D Cornish) Climatic Influences on Landfill Gas Extraction, with a Unique Comparison Landfill Leachate Treatability of Typical Performance Between (LJ Strachan, HD Robinson and LR Gravelet- Landfills Located in the Highveld and Blondin) KZN Coastal Regions (BJ Barratt, BL Jewaskiewitz and BL Mills) Behaviour of Baling-Wrapping MSW Landfill Application Buffer Zones: The Long Term Interface in Spain (L Moodley, R Winn and J Parkin) (Dr José M Baldasano) GCLs: The Buffelsdraai Landfill Experience Lunch (GJ Payne) Sponsored By Wilson & Pass Lunch Sponsored By Lunch Asphalt Liners in Landfill Construction (Dr T Egloffstein and G Burkhardt) Bosch Stemele Sponsored By Aquatan (Pty) Ltd Design and Construction of a Deep Upstream Landfill Gas Extraction Schemes - A Groundwater Cutoff Trench Contractor's Viewpoint (J Shamrock, J Glendinning, J Mzisa and (J Butt) H Janse van Rensburg) eThekwini Municipality: Electron Road Waste Drainage Sand Bulk Sampling a New Management Facility Presentation Lined Residue Disposal Facility (C Wise) (I Nyirenda and C van Renssen) Mechanical Biological Treatment (MBT) Presentation Tea (R Lombard) Geosynthetic Clay Liners (GCLs) – The Effects of Peel Strength on Performance (C MacKenzie and N du Toit) Addressing an Integrated Approach to the use of Alternative Technologies as an Economically Viable Alternative to Landfill (C Whyte) Cocktails Drinks Sponsored By Barloworld Landfill Interest Group Seminar 18 to 20 October 2011 Final Programme Session 1 Session 2 Session 3 08:00 09:00 Session Chairman: John Parkin 12:50 Session Chairman: Logan Moodley 15:50 Session Chairman: Geoff Purnell 18:00 + 09:00 09:30 13:50 16:10 09:30 10:30 11:05 11:40 12:15 13:50 14:30 15:10 16:10 16:50 10:30 11:05 11:40 12:15 12:50 14:30 15:10 15:50 16:50 17:30 Session 4 Session 5 Session 6 Session Chairman: 10:10 Session Chairman: Colin Redman 12:30 Session Chairman: 16:00 10:30 13:30 08:10 08:50 09:30 10:30 11:10 11:50 13:30 14:10 14:50 08:50 09:30 10:10 11:10 11:50 12:30 14:10 14:50 15:30 Session 7 Session 8 Session Chairman: Peter Davies 10:10 Session Chairman: Peter Davies 12:30 10:30 13:30 08:15 10:30 2011-09-13: Final 10:10 12:30 Slope Stability of Liners and Slope Stability of Liners and Covers Workshop Covers Workshop Rick Thiel Rick Thiel COMPOSITION OF WASTE LANDFILLED AT METROPOLITAN LANDFILLS AND THE IMPACT OF THE NEW DRAFT WASTE REGULATIONS Wise C C*, Emery R C* and Coetzee J A* * Jeffares & Green (Pty) Ltd. P.O.Box 38561, Pinelands, 7430, Tel: +27 21 532 0940; E-mail: 2 EXISTING WASTE CHARACTERISATION STUDIES A number of waste characterisation studies have been undertaken within metropolitan areas in the last 10 to 15 years. Most of these have been focused on establishing the amount of recyclables available in waste streams from various income groups in order to determine the viability of initiating recycling programmes. As such these studies take representative samples from various areas (generally domestic waste with some commercial waste) and divide it into its various waste fractions. These include Ingerop (1999), KV3 et al. (2004), Gibb (2008), Ball (2003), Ball (2004), Haultec (1998) and GreenEng (2010). Each of these studies have been useful for their intended purpose, but are generator- based and are thus focused on the breakdown within the waste streams and not the actual quantity that’s is landfilled. There are fewer waste characterisations that attempt to analyse the composition of the waste actually landfilled. This is understandable given the complexity and difficulty of such a task. However, four studies have been identified that are specifically landfill-based characterisation. These are: 1. Ball (2001): Landfill Salvager Survey. Report for the Greater Johannesburg Metropolitan Council. 2. PNDA et. al. (2007): Strategic Road Map Phase 2 for Pikitup. 3. Akhile Consortium (2010): Section 78(3) Analysis for the Solid Waste Department, City of Cape Town, Status Quo Report. 4. GreenEng / Jeffares & Green (2010): Analysis of the Bisasar Road Landfill weighbridge data for the sizing of Electron Road Transfer Station. Of these four, the three most recent studies PNDA et al (2007), Akhile (2010) and GreenEng (2010) were analysed in more detail as they were considered more recent. A summary of the purpose, assumptions and limitations of each of these studies follows. 2.1 Pikitup Strategic Road Map, Phase 2 (2007) This study was focused primarily on an analysis of the waste currently going to landfill with the aim of identifying and quantifying specific streams for diversion. It was a comprehensive study that included a summary of the composition of waste landfilled to Municipal landfills in Johannesburg. The characterisation of the household waste was based on KV3 et al. (2004), while the remaining quantities were derived from weighbridge data. Some assumptions were made with regard to the composition of non-domestic streams (such as illegal dumping and street cleaning), but these quantities are relatively small and the assumptions would not significantly affect the general conclusions drawn. The data used was for the 2005/2006 financial year. 2.2 Section 78(3) review for the City of Cape Town, Status Quo report This study was also focused on the waste being landfilled at Municipal sites in an attempt to quantify the waste fraction that could be diverted for beneficiation. The characterisation of the household waste was based on Gibb (2008), while the other fractions were derived from weighbridge data. It should be noted that the definition of recyclables in the household waste characterisation study included all plastic and paper even if it was contaminated. This study also looked at hazardous waste, which was quantified based on an analysis of the weighbridge data (for commercial and industrial hazardous waste) and Gibb (2008) for household hazardous waste. The quantities were determined for the 2008/2009 financial year. 2.3 Bisasar Road Landfill Waste Characterisation, Durban Solid Waste This study was undertaken by GreenEng for Jeffares & Green (Pty) Ltd in order to accurately determine the size of the new Electron Road Transfer station. It looked at weighbridge data from 2006 until 2010 and established an average for each of the major waste streams. It was 2 however not the intention of the study to break down the household waste stream further (i.e into recyclables, garden etc.). 3 SUMMARY OF RESULTS FROM EXISTING LANDFILL-BASED CHARACTERISATION STUDIES The results from the three different landfill-based waste characterisations are summarised and presented here. 3.1 Pikitup Strategic Road Map, Phase 2 (2007) The Strategic Road Map study categorised the waste in the landfill, based on the collection mechanism. The following categories were thus used; Collection Vehicles, Street Cleaning, Illegal Dumping, Drop offs, Informal Settlements, Bulk, Builders Rubble and Greens. However, each of these categories was divided into various fractions such as recyclables, garden refuse, putrescibles etc. This data was thus collated to provide an estimated waste characterisation of the waste landfilled for the 2005/2006 financial year, as shown in Table 1. The report at the time allowed for 15% greens in the household waste. However, since then greens are not allowed to be disposed of in wheelie bins. The data was thus adjusted to only allow for 2% greens in household waste, assuming some residents will “hide” greens in their wheelie bins. Table 1: Estimated waste characterisation (by mass) for waste landfilled in Municipal landfill sites in Johannesburg for the 2005/2006 financial year (adapted from PDNA et al. 2007) Annual Mass Landfilled (t/yr x 1000) Recyclables 206.1 13.4% Putrecibles 126.1 8.2% Greens and Garden 166.0 10.8% Fines/residue 25.3 14.7% Misc. & other 351.3 22.9% Compacted bulk 37.2 2.4% Builders' rubble 420.8 27.5% Total 153.0 This data was compared with the Pikitup IWMP which showed a greens percentage for 2009/2010 as 9% of the total waste landfilled, which compares well with the data in Table 1 as it allows for some greens diversion that has been taking place. 3.2 City of Cape Town Section 78(3) Review (2010) This study characterised the waste landfilled on Municipal Landfill sites according to the new Waste Act classification system. There was therefore a defined split between hazardous, inert and general waste. General waste was further split between domestic and commercial/industrial. A summary of the estimated waste characterisation as reported in that study for the 2008/2009 financial year is provided in Table 2. It must be noted that this study indicated that this data should be used with caution as the basic underlying assumptions were applicable for the purposes of that study and may not apply for other purposes. 3 Table 2: Estimated waste characterisation (by mass) for waste landfilled in Municipal landfill sites in Cape Town for the 2008/2009 financial year (Akhile et al. 2010) Annual Mass Landfilled (t/yr x 1000) General 1,4 92% Household (incl. informal settlements) 571 36% Recyclables 39 2% Fod 84 5% Other 148 9% Street and area cleaning (excl. Builders rubble) 94 6% Trade (commercial & industrial, excl hazardous) 301 19% Inert Waste 479 30% Builders rubble 349 22% Greens directly to landfill as free waste 31 2% Household greens (incl. informal) 99 6% Hazardous 132 8% Household 41 3% Industrial 6 4% Business & Commercial 25 2% Total 1,57 3.3 Bisasar Road Landfill Waste Characterisation (2010) This study was based only on the weighbridge data and was therefore a course estimate than the previous two studies. Nonetheless, some of the comparisons are useful for further analysis. The categories that were used in the characterisation were based on the classification at the weighbridge, e.g. Durban Solid Waste vehicles, builders’ rubble, mixed loads etc. The average for the 4 years, 2007 until 2010 are presented in Table 3. Table 3: Average waste characterisation (by mass) for waste landfilled in Bisasar landfill site in Durban for the period from 2007 until 2010 (GreenEng et al. 2010) Annual Mass Landfilled   (t/yr x 1000)   DSW Loads 417.8 38.0% General Solid Waste 69.7 6.3% Garden Refuse 36.6 3.3% Builder's Rubble 107.6 9.8% Mixed Loads 13.4 1.2% Sand & Cover Mat. 418.8 38.1% Tyres 1.0 0.1% Light Refuse 0.2 0.0% Other 3.7 3.1% Total 1098.8 4 4 COMPARISON As can be noted, the categories used for the waste characterisation were different in each of the studies, which made a direct comparison difficult. In particular, the general waste fraction for the Durban data was not further categorised into recyclables and putrescibles. Thus, only the Johannesburg and Cape Town data could be compared by grouping the various waste fractions into 5 broad categories, namely; recyclables, non-green organics (putrescibles, food and other organics excluding greens), builders rubble (which included sand), greens (garden refuse and other greens from parks etc.) and other. This was considered sufficient for the purposes of this study as they represent the major waste fractions that would be diverted from landfill. The comparison of the waste categorisation for Johannesburg and Cape Town are presented in Table 4. Table 4: Average waste characterisation (by mass) for waste landfilled in Johannesburg and Cape Town Cape Town Johannesburg   (2008/2009) (2005/2006) Annual Mass Annual Mass Landfilled Landfilled (t/yr x 1000) (t/yr x 1000) Recyclables 39.2 21.5% 206.1 13.4% Non-green organics 152.3 9.7% 126.1 8.2% Greens and Garden 129.9 8.2% 166.0 10.8% Builders' rubble 348.8 22.1% 420.8 27.5% Other 606.5 38.5% 613.9 40.0% TOTAL 1576.7 1532.9 The differences between the data for each of the waste fractions is discussed briefly. 4.1 Recyclables Although it may appear that Cape Town generates more recyclables, the reason for the higher apparent figure is that the methodology used in the household waste characterisation study (Gibb 2008) included portions of the fines, which appeared to be paper or plastic, in the paper and plastic categories. As such the amount of recyclables tended to be over-estimated. 4.2 Non- green Organics The percentage of non-green organics are relatively similar with Cape Town at 9.7% and Johannesburg at 8.2%. It must however be noted that the Cape Town figure excludes organic (non-hazardous) special wastes (approx. 37, 000 tons/year) that is landfilled at the Vissershok H:h site. That same waste fraction in Johannesburg would be landfilled at one of the private sites and was thus taken out of the analysis for comparison. It should be noted that this fraction however has a high diversion and beneficiation value. 4.3 Greens and Garden Waste It would appear that Johannesburg (10.8%) landfills slightly more green waste than Cape Town (8.2%). This could however be attributed to the Johannesburg data being slightly older (2005/2006) and thus does not make allowance for the diversion measures that Pikitup have subsequently initiated. For example, Cape Town’s 2008/2009 figures show that they are diverting approximately 67,000 tons/year of green waste by means of a chipping contract, representing a diversion of 35% of the estimate mass of green generated. 5 4.4 Builders Rubble The mass of builders rubble tends to vary quite significantly from year to year as the building industry fluctuates. Thus a comparison over different financial years is not ideal. However, the difference between mass of builders rubble landfilled in Cape Town (22.1%) and Johannesburg (27.5%) is considered to be relatively close given that the figures were recorded two years apart. 5 AIRSPACE CONSUMED BY WASTE CATEGORIES Although most waste characterisation is normally undertaken by means of mass, the volume that the waste consumes in the landfill is more relevant when it comes to determining the life of the landfill. The waste characterisations, as shown in Table 4 were converted to estimated landfill volumes by means of the average landfill densities shown in Table 5, obtained from de Wit (2009). Table 5: Average landfill compaction densities for various waste fractions (de Wit, 2009) Density 3 kg/m Glas 830 Plastic 326 Builders Rubble 1502 Paper 606 Cans 20 Grens 20 Wet waste (food etc.) 900 3 The landfilled density of all other wastes was assumed to be 800 kg/m . Using the household recyclables breakdown from Gibb (2008) and KV3 (2004), the weighted 3 average density of recyclables on landfill was calculated as 512 kg/m for Cape Town and 3 540 kg/m for Johannesburg. The percentage of each waste fraction landfilled by volume could thus be calculated and is shown along with the percentage by mass for Cape Town and Johannesburg in Figures 1 and 2. Figure 1: Estimated waste characterisation (by mass and volume) for waste landfilled in Municipal landfill sites in Cape Town for the 2008/2009 financial year 6 Figure 2: Estimated waste characterisation (by mass and volume) for waste landfilled in Municipal landfill sites in Johannesburg for the 2005/2006 financial year 5.1 Greens The most striking result is that greens and garden refuse, although relatively small with regards to mass, make up a significant portion by volume. As such it is evident that, even though the figures for Johannesburg be an over estimate for the current situation (due to the data preceding some waste diversion initiatives), there is no doubt that the diversion of greens would not make a significant impact with respect to mass, but would make a far-reaching impact on extending the lifespan of a landfill. 5.2 Builders Rubble Builders’ rubble, although making up a large portion with respect to mass, has less on an impact on the landfill airspace consumed. Certainly there is significant merit in diverting builders’ rubble from landfill sites, but that will not have as significant an impact on the life of the landfill as would greens. 5.3 Recyclables Recyclables are generally considered a prized waste stream for diversion, primarily because of the value attached to that waste. This data also shows that recyclables can contribute to a relatively large portion of the annual landfill airspace consumed. 5.4 Tyres (supplementary analysis to graphs in Figure 1 and 2) Waste tyres has for many years been considered a significant problem on landfill sites. The Bisasar Road data (see Table 3) recorded the mass of waste tyre separately and was thus used to determine the percentage of the annual airspace that is consumed by tyres. 3 The bulk density of waste tyres has been previously reported to be between 350 kg/m and 3 500 kg/m (Wallingford, 2005). For the purposes of this study it was assumed the no waste 3 collects between the tyres on a landfill and thus a conservative landfill density of 350 kg/m was used. In 2007, 1,777 tons of tyres were disposed of on the Bisasar Road landfill. Using the landfill densities in Table 5, the percentage by volume of the total airspace consumed by tyres was 0.4%. Furthermore, the South African Tyre Recycling Process Company (SATRP) reports that the larger Cape Town area produces about 12,000 tons of waste tyres per year, of which 3,000 tons per year are recycled. Assuming the remaining 9,000 tons are landfilled, this figure would constitute 1.0% of the City’s landfill airspace. Thus, the data appears to indicate that waste tyres do not consume as much landfill airspace as is commonly thought. 7 6 NEW DRAFT WASTE REGULATIONS AND STANDARDS 6.1 Greens The Draft National Standard for Disposal of Waste to Landfill (Clause 5(1)) has set targets for the diversion of a number of particular waste streams. The majority of these are hazardous waste, with the exception of tyres and greens. The effect of these targets on future landfill airspace was calculated based on the results of this estimated waste characterisation. A proposed target has been set to divert 25% (from baseline) of garden waste in 5 years and 50% in 10 years. Using the data presented in Figures 1 and 2, the impact that this would have on landfill airspace for Cape Town and Johannesburg is shown in Table 6. Table 6: Estimated landfill airspace savings (by volume) if Draft National Standard for Disposal of Waste to Landfill targets are achieved for diversion of Green waste Landfill Airspace Savings Greens Diversion Rate Cape Town Johannesburg 25% (5 year target) 6.6% 8.6% 50% (10 year target) 13.1% 17.3% It can thus be estimated that if the 10 year target for greens is achieved (50% diversion) then landfill lifespans could potentially be extended by between 13% and 17%. 6.2 Recyclables The Domestic Waste Collection Standard (DEA, 2011) states (Clause 4.1) that “All domestic waste must be sorted at source (i.e. the -households) in all Metropolitan and secondary cities”. There is thus strong pressure for Metropolitan municipalities to initiate a system to divert recyclables from landfill. Although many studies calculate the financial viability of at-source separation and recycling initiatives based on the income from sales of recyclables, a very important consideration is the financial benefit of landfill airspace savings. The landfill airspace savings for Johannesburg and Cape Town were estimated assuming that either 25% or 50% of the recyclables are diverted from landfill. This is shown in Table 7. Table 7: Estimated landfill airspace savings (by volume) for 25% and 50% recyclables diversion Landfill Airspace Savings Recyclables Diversion Rate Cape Town Johannesburg 25% 6.7% 4.0% 50% 13.4% 7.0% It can thus be estimated that a diversion of 50% of the recyclables (which is relatively difficult to achieve) would result in extending landfill lifespans by between 7% and 13%. 6.3 Summary Based on the estimates presented here, a 50% diversion of green waste has almost twice as much impact on extending the life of a landfill than if 50% of recyclables can be diverted. One has to also consider how easy it would be to divert greens as opposed to recyclables. The breakdown of the green waste sources for Cape Town and Johannesburg is given in Table 8. 8

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