20 – Operation and Maintenance 1/45 “There is no sensible reason to design and prepare for a better engineered landfill if it is not operated in a better way than an open dump” (Flinthoff, 1976)

20 – Operation and Maintenance 2/45 Overview Overview 20.1 Management 20.2 Capacity building Operators 20.3 Operational aspects (filling/covering) 20.4 Leachate treatment 20.5 Landfill gas 20.6 Monitoring systems 20.7 Scavengers

20 – Operation and Maintenance 3/45 Key decisions (1) n Technical resources and skills available? n Required skills: waste management, civil engineering, hydrogeology, geotechnical engineering, hydrology n Acquisition options: building in municipal organisation, contracting to consultants, outsourcing to waste management contractors n Financial resources made available? 20.1 Management

20 – Operation and Maintenance 4/45 Key decisions (2) n Type of equipment to be used for placement and compaction? n Specialised equipment (compactor): high density, saves volume, but higher investment and maintenance cost n Common equipment (agriculture, road construction): lower density, but cheaper and easier to service 20.1 Management

20 – Operation and Maintenance 5/ Management Equipment

20 – Operation and Maintenance 6/45 Key decisions (3) n Scavengers allowed on site? n Health and safety hazards exist for both scavengers and landfill employees n Informal recycling is disruptive to landfill operation due to interference with the work and fires 20.1 Management

20 – Operation and Maintenance 7/ Capacity building of operators Disposal plan n Key element of design n Describes appropriate sequence of filling to achieve final land form n Purpose is to minimise environmental impact and at the same time minimise necessary construction works 20.2 Capacity building of operators

20 – Operation and Maintenance 8/ Capacity building of operators Disposal plan (cont’d) … can be achieved by: n minimising area being filled (12-18 months) n accelerating restoration of filled parts n minimising double handling of excavated material n allowing progressive installation of gas and water controls n permitting optimum development of access and haul roads 20.2 Capacity building of operators

20 – Operation and Maintenance 9/ Capacity building of operators General principles n Waste should be compacted in thin layers (~ 30 cm up to 2 m. thick) n Compacted waste should be covered on daily basis n No biodegradable waste should be deposited in water n Open burning of waste should not be permitted n Inspections for vermin should be frequent and measures taken to prevent infestations 20.2 Capacity building of operators

20 – Operation and Maintenance 10/ Capacity building of operators General principles n Litter should be collected regularly from around the site n Drainage ditches should be kept free of blockages n Site acces roads should be regurarly inspected and if necessary repaired n Keep records of all waste deliveries to the site n Environmental monitoring should be performed on routine basis n Public should be excluded from the site for their own safety 20.2 Capacity building of operators

20 – Operation and Maintenance 11/ Operation aspects Covering/Filling n Three general ways of landfilling depending upon topography and landscape: 1. Trench 2. Ramp 3. Area 20.3 Capacity building of operators

20 – Operation and Maintenance 12/ Operational aspects Trench landfilling

20 – Operation and Maintenance 13/ Operational aspects Ramp landfilling

20 – Operation and Maintenance 14/ Operational aspects Area landfilling

20 – Operation and Maintenance 15/ Operational aspects Settlement n … can compromise the after use, especially when uneven settlement damages the final cover n Speed and amount vary with initial compaction n MSW can reach a density of 1.0 tonne per m³ n Waste placement 0.5 tonne per m³: 50% expected n Compaction to 0.8 tonne per m³: 25% expected

20 – Operation and Maintenance 16/45 n Waste acceptance requires: n access roads n reception facilities (office including heating, lighting, drinking water, toilet and wash facilities) n registration facilities (volumetric estimation or weighbridge, administration system Operational aspects Basic landfill site infrastructure

20 – Operation and Maintenance 17/ Operational aspects Basic landfill site infrastructure

20 – Operation and Maintenance 18/ Operational aspects Daily cover n Reduces attraction of birds and rodents n Reduces suitable habitat for vermin and flies n Provides better surface for vehicles n Reduces exposure to atmospheric conditions n Reduces wind-blown litter n Reduces direct infiltration of water into the waste

20 – Operation and Maintenance 19/ Operational aspects Daily cover

20 – Operation and Maintenance 20/ Operational aspects Planning supply of cover material n Rarely a site can supply all soil material required for bunds, daily, temporary and final cover: check what is available n Some waste materials (contaminated soil, ashes, construction and demolition waste) is suitable for daily cover: plan provisions for temporary storage n In case of deficit: plan a “borrow area”

20 – Operation and Maintenance 21/ Leachate Groundwater polution n … is one of the major concerns in landfill design n … is caused by leachate entering the subsoil n Quantity and quality of leachate depend upon local climate, nature of wastes, and measures to prevent entry of rain into the waste

20 – Operation and Maintenance 22/ Leachate Water balance

20 – Operation and Maintenance 23/ Leachate Two classical approaches n “Attenuate and disperse” design: a certain amount of leachate entering into the subsoil is considered acceptable, soil processes reduce the impact n “Containment”design: a natural or synthetic barrier inhibits release of leachate into the subsoil

20 – Operation and Maintenance 24/ Leachate Attenuate and disperse

20 – Operation and Maintenance 25/ Leachate Drainage system attenuate and disperse

20 – Operation and Maintenance 26/ Leachate Containment design (sanitary landfilling)

20 – Operation and Maintenance 27/ Leachate Containment design (sanitary landfilling)

20 – Operation and Maintenance 28/ Leachate Drainage system (sanitary landfill)

20 – Operation and Maintenance 29/ Leachate Drainage system (sanitary landfill)

20 – Operation and Maintenance 30/ Leachate Leachate treatment n Leachate can not be discharged untreated n Treatment can be necessary in first approach, but a must in second approach n Amounts of leachate can be reduced by recirculation n Treatment options are municipal waste water treatment plant, lagoons, wetlands, activated sludge systems

20 – Operation and Maintenance 31/ Leachate Leachate treatment (lagoon)

20 – Operation and Maintenance 32/ Leachate Leachate treatment (wetland)

20 – Operation and Maintenance 33/ Leachate Leachate treatment (activated sludge)

20 – Operation and Maintenance 34/ Landfill gas n Degradation of organics produces landfill gas (LFG) n LFG contains mainly methane and carbon dioxide n Methane is potentially explosive and a greenhouse gas n Carbon dioxide is potentially asphyxiating n Risks: on-site and migration off-site

20 – Operation and Maintenance 35/ Landfill gas Landfill gas control n LFG risks can be reduced by means of a gas collection system n Options: passive venting and flaring or active extraction and utilisation and / or flaring

20.5 Landfill gas Gas well installation

20.5 Landfill gas Gas well construction

20.5 Landfill gas gas drainage

20.5 Landfill gas LFG extraction

20.5 Landfill gas LFG extraction (without compressor)

20 – Operation and Maintenance 41/ Monitoring systems n Purpose: demonstrate functioning of protection measures n Groundwater: boreholes and sampling points n Landfill gas: inspection of vegetation or boreholes and sampling points n Nuisance (dust, odour, wind-blown litter): site inspection

20 – Operation and Maintenance 42/ Social aspects Scavengers n PM Maarten Siebel

20 – Operation and Maintenance 43/45 Conclusion n Landfill operation has many similarities with civil engineering design, but requires additional skills in the project team n Disposal plan and proper site management reduce future operational and environmental problems operational and environmental problems n Design includes building or acquiring skills, equipment, waste placement, cover material, leachate containment, leachate and landfill gas control and monitoring