20 – operation and maintenance 1/45 “there is no sensible reason to design and prepare for a...

20 – Operation and Maintenance20 – Operation and Maintenance

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““There is no sensible reason to design and prepare for a There is no sensible reason to design and prepare for a better engineered landfill if it is not operated in a better better engineered landfill if it is not operated in a better

way than an open dump” (Flinthoff, 1976)way than an open dump” (Flinthoff, 1976)


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Overview Overview

20.1 Management20.1 Management

20.2 Capacity building Operators20.2 Capacity building Operators

20.3 Operational aspects (filling/covering)20.3 Operational aspects (filling/covering)

20.4 Leachate treatment20.4 Leachate treatment

20.5 Landfill gas20.5 Landfill gas

20.6 Monitoring systems20.6 Monitoring systems

20.7 Scavengers20.7 Scavengers


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Key decisions (1)Key decisions (1)

Technical resources and skills available?Technical resources and skills available?

Required skills: waste management, civil engineering,Required skills: waste management, civil engineering,

hydrogeology, geotechnical engineering, hydrology hydrogeology, geotechnical engineering, hydrology

Acquisition options: building in municipal organisation,Acquisition options: building in municipal organisation,

contracting to consultants, outsourcing to waste management contracting to consultants, outsourcing to waste management

contractors contractors

Financial resources made available?Financial resources made available?




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Key decisions (2) Key decisions (2)

Type of equipment to be used for placement andType of equipment to be used for placement and

compaction? compaction?

Specialised equipment (compactor): high density, saves

volume, but higher investment and maintenance cost

Common equipment (agriculture, road construction): lower

density, but cheaper and easier to service



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EquipmentEquipment


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Key decisions (3) Key decisions (3)

Scavengers allowed on site?Scavengers allowed on site?Health and safety hazards exist for both

scavengers

and landfill employees

Informal recycling is disruptive to landfill operation

due to interference with the work and fires



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20.2 Capacity building of operators 20.2 Capacity building of operators Disposal planDisposal plan

Key element of designKey element of design

Describes appropriate sequence of filling to achieve final Describes appropriate sequence of filling to achieve final

land form land form

Purpose is to minimise environmental impact and at thePurpose is to minimise environmental impact and at the

same time minimise necessary construction works same time minimise necessary construction works

20.2 Capacity building of operators20.2 Capacity building of operators


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20.2 Capacity building of operators 20.2 Capacity building of operators Disposal plan (cont’d)Disposal plan (cont’d)

… … can be achieved by:can be achieved by:

minimising area being filled (12-18 months)minimising area being filled (12-18 months)

accelerating restoration of filled parts accelerating restoration of filled parts

minimising double handling of excavated materialminimising double handling of excavated material

allowing progressive installation of gas and water controlsallowing progressive installation of gas and water controls

permitting optimum development of access and haul roadspermitting optimum development of access and haul roads



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20.2 Capacity building of 20.2 Capacity building of operatorsoperators

General principlesGeneral principles Waste should be compacted in thin layers (Waste should be compacted in thin layers (~ 30 cm up to 2 m. ~ 30 cm up to 2 m.

thick)thick)

Compacted waste should be covered on daily basisCompacted waste should be covered on daily basis

No biodegradable waste should be deposited in waterNo biodegradable waste should be deposited in water

Open burning of waste should not be permittedOpen burning of waste should not be permitted

Inspections for vermin should be frequent and measures taken Inspections for vermin should be frequent and measures taken

to prevent infestationsto prevent infestations



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20.2 Capacity building of 20.2 Capacity building of operatorsoperators

General principlesGeneral principles Litter should be collected regularly from around the siteLitter should be collected regularly from around the site

Drainage ditches should be kept free of blockagesDrainage ditches should be kept free of blockages

Site acces roads should be regurarly inspected and if Site acces roads should be regurarly inspected and if

necessary necessary

repairedrepaired

Keep records of all waste deliveries to the siteKeep records of all waste deliveries to the site

Environmental monitoring should be performed on routine Environmental monitoring should be performed on routine

basisbasis

Public should be excluded from the site for their own safetyPublic should be excluded from the site for their own safety



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20.3 Operation aspects20.3 Operation aspects Covering/Filling Covering/Filling

Three general ways of landfilling depending upon Three general ways of landfilling depending upon

topography and landscape:topography and landscape:

1. Trench

2. Ramp

3. Area



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20.3 Operational aspects20.3 Operational aspectsTrench landfillingTrench landfilling


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3.4.3 Operational aspects3.4.3 Operational aspectsRamp landfillingRamp landfilling


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3.4.3 Operational aspects3.4.3 Operational aspectsArea landfillingArea landfilling


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3.4.3 Operational aspects3.4.3 Operational aspectsSettlement Settlement

… … can compromise the after use, especially when can compromise the after use, especially when

unevenuneven

settlement damages the final cover settlement damages the final cover

Speed and amount vary with initial compactionSpeed and amount vary with initial compaction

MSW can reach a density of 1.0 tonne per m³MSW can reach a density of 1.0 tonne per m³

Waste placement 0.5 tonne per m³: 50% expectedWaste placement 0.5 tonne per m³: 50% expected

Compaction to 0.8 tonne per m³: 25% expectedCompaction to 0.8 tonne per m³: 25% expected


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Waste acceptance requires:Waste acceptance requires: access roads

reception facilities (office including heating, lighting,

drinking water, toilet and wash facilities)

registration facilities (volumetric estimation or

weighbridge, administration system

3.4.3 Operational aspects3.4.3 Operational aspectsBasic landfill site infrastructureBasic landfill site infrastructure


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20.3 Operational aspects20.3 Operational aspectsBasic landfill site infrastructureBasic landfill site infrastructure


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20.3 Operational aspects 20.3 Operational aspects Daily coverDaily cover

Reduces attraction of birds and rodents Reduces attraction of birds and rodents

Reduces suitable habitat for vermin and fliesReduces suitable habitat for vermin and flies

Provides better surface for vehiclesProvides better surface for vehicles

Reduces exposure to atmospheric conditionsReduces exposure to atmospheric conditions

Reduces wind-blown litterReduces wind-blown litter

Reduces direct infiltration of water into the wasteReduces direct infiltration of water into the waste


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20.3 Operational aspects 20.3 Operational aspects Daily coverDaily cover


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20.3 Operational aspects 20.3 Operational aspects Planning supply of cover materialPlanning supply of cover material

Rarely a site can supply all soil material required for bunds,Rarely a site can supply all soil material required for bunds,

daily, temporary and final cover: check what is available daily, temporary and final cover: check what is available

Some waste materials (contaminated soil, ashes, constructionSome waste materials (contaminated soil, ashes, construction

and demolition waste) is suitable for daily cover: plan provisions and demolition waste) is suitable for daily cover: plan provisions

for temporary storage for temporary storage

In case of deficit: plan a “borrow area”In case of deficit: plan a “borrow area”


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20.4 Leachate 20.4 Leachate Groundwater polutionGroundwater polution

… … is one of the major concerns in landfill designis one of the major concerns in landfill design

… … is caused by leachate entering the subsoilis caused by leachate entering the subsoil

Quantity and quality of leachate depend upon localQuantity and quality of leachate depend upon local

climate, nature of wastes, and measures to prevent entry climate, nature of wastes, and measures to prevent entry

of rain into the waste of rain into the waste


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20.4 Leachate 20.4 Leachate Water balanceWater balance

rain fall evapotranspiration

infiltration

discharge

infiltration in the soil


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20.4 Leachate 20.4 Leachate Two classical approachesTwo classical approaches

““Attenuate and disperse” design: a certain amount ofAttenuate and disperse” design: a certain amount of

leachate entering into the subsoil is considered leachate entering into the subsoil is considered

acceptable, soil processes reduce the impactacceptable, soil processes reduce the impact

““Containment”design: a natural or synthetic barrier Containment”design: a natural or synthetic barrier

inhibitsinhibits

release of leachate into the subsoilrelease of leachate into the subsoil


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20.4 Leachate 20.4 Leachate Attenuate and disperseAttenuate and disperse


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20.4 Leachate 20.4 Leachate Drainage system attenuate and Drainage system attenuate and

dispersedisperse


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20.4 Leachate 20.4 Leachate Containment design (sanitary Containment design (sanitary

landfilling)landfilling)


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20.4 Leachate 20.4 Leachate Containment design (sanitary Containment design (sanitary

landfilling)landfilling)


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20.4 Leachate 20.4 Leachate Drainage system (sanitary landfill)Drainage system (sanitary landfill)


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20.4 Leachate 20.4 Leachate Drainage system (sanitary landfill)Drainage system (sanitary landfill)


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20.4 Leachate 20.4 Leachate Leachate treatmentLeachate treatment

Leachate can not be discharged untreatedLeachate can not be discharged untreated

Treatment can be necessary in first approach, but a mustTreatment can be necessary in first approach, but a must

in second approach in second approach

Amounts of leachate can be reduced by recirculationAmounts of leachate can be reduced by recirculation

Treatment options are municipal waste water treatmentTreatment options are municipal waste water treatment

plant, lagoons, wetlands, activated sludge systems plant, lagoons, wetlands, activated sludge systems


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20.4 Leachate 20.4 Leachate Leachate treatment (lagoon)Leachate treatment (lagoon)


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20.4 Leachate 20.4 Leachate Leachate treatment (wetland)Leachate treatment (wetland)


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20.4 Leachate 20.4 Leachate Leachate treatment (activated Leachate treatment (activated

sludge)sludge)


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20.5 Landfill gas 20.5 Landfill gas

Degradation of organics produces landfill gas (LFG)Degradation of organics produces landfill gas (LFG)

LFG contains mainly methane and carbon dioxideLFG contains mainly methane and carbon dioxide

Methane is potentially explosive and a greenhouse gasMethane is potentially explosive and a greenhouse gas

Carbon dioxide is potentially asphyxiatingCarbon dioxide is potentially asphyxiating

Risks: on-site and migration off-siteRisks: on-site and migration off-site


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20.5 Landfill gas 20.5 Landfill gas Landfill gas controlLandfill gas control

LFG risks can be reduced by means of a gasLFG risks can be reduced by means of a gas

collection systemcollection system

Options: passive venting and flaring or activeOptions: passive venting and flaring or active

extraction and utilisation and / or flaring extraction and utilisation and / or flaring

20.5 Landfill gas20.5 Landfill gas Gas well installationGas well installation

20.5 Landfill gas20.5 Landfill gas Gas well constructionGas well construction

20.5 Landfill gas20.5 Landfill gas gas drainagegas drainage

20.5 Landfill gas20.5 Landfill gas LFG extractionLFG extraction

20.5 Landfill gas20.5 Landfill gas LFG extraction (without LFG extraction (without

compressor)compressor)


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20.6 Monitoring systems20.6 Monitoring systems

Purpose: demonstrate functioning of protection measuresPurpose: demonstrate functioning of protection measures

Groundwater: boreholes and sampling pointsGroundwater: boreholes and sampling points

Landfill gas: inspection of vegetation or boreholes andLandfill gas: inspection of vegetation or boreholes and

sampling pointssampling points

Nuisance (dust, odour, wind-blown litter): site inspectionNuisance (dust, odour, wind-blown litter): site inspection


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20.7 Social aspects20.7 Social aspectsScavengersScavengers

PM Maarten SiebelPM Maarten Siebel


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Conclusion Conclusion

Landfill operation has many similarities with civil engineeringLandfill operation has many similarities with civil engineering

design, but requires additional skills in the project team design, but requires additional skills in the project team

Disposal plan and proper site management reduce futureDisposal plan and proper site management reduce future

operational and environmental problemsoperational and environmental problems

Design includes building or acquiring skills, equipment, wasteDesign includes building or acquiring skills, equipment, waste

placement, cover material, leachate containment, leachate and placement, cover material, leachate containment, leachate and

landfill gas control and monitoring landfill gas control and monitoring

20 – operation and maintenance 1/45 “there is no sensible reason to design and prepare for a...

Documents

landfill gas gas drainage20

landfill gas control

landfill gas lfg extraction20

sampling pointslandfill

compressor20 operation

site inspection20 operation

leachate containment

additional skills