How can geophysical methods help to characterize landfills? Focus - - PowerPoint PPT Presentation

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How can geophysical methods help to characterize landfills? Focus - - PowerPoint PPT Presentation

Sep 24, 2023 36 likes •523 views

How can geophysical methods help to characterize landfills? Focus on Onoz landfill David Caterina , Itzel Isunza Manrique , Frdric Nguyen 1 RAWFILL Agenda of the presentation A short introduction to geophysics Landfill

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How can geophysical methods help to characterize landfills?

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David Caterina, Itzel Isunza Manrique , Frédéric Nguyen

Focus on Onoz landfill

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Agenda of the presentation

  • A short introduction to geophysics
  • Landfill investigation
  • Context
  • Extension
  • Composition
  • Landfill monitoring
  • Take home message
  • Landfill of Onoz

2 RAWFILL

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Agenda of the presentation

  • A short introduction to geophysics
  • Landfill investigation
  • Context
  • Extension
  • Composition
  • Landfill monitoring
  • Take home message
  • Landfill of Onoz

3 RAWFILL

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A short introduction to geophysics: Objectives

Mapping spatial variations in:

  • Lithology/waste type/density
  • Water content
  • Pore fluid or total dissolved solids
  • Mechanical properties
  • Metallic content

Monitoring changes in:

  • Waste/contaminant mass
  • Tracer concentration
  • Amendement injection
  • Compaction/density/porosity
  • Gas production

Translate the geophysical variations or changes into property of interestassuming a relationship.

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Why geophysics?

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Example: contaminant detection

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Classical approach

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Classical approach

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Classical approach

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Classical approach

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Classical approach

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Accurate but low-density spatial and temporal information

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With geophysics… (here ERT)

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Suspect zone

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Focus on the geophysical anomaly

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  • Non to minimally invasive
  • Relatively low cost
  • Large coverage
  • See through technology
  • Indirect information
  • Resolution decreases with

depth

  • Prone to modeling errors

(artefacts)

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Pro ro and and co cons

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Different methods...

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Seismics ERT/IP EM Magnetic

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Method Bulk (geo)physical property Relevant information Acquisition/(ex. of main limitations) Seismics (refraction, surface waves, reflection, ambient noise) Elastic moduli, density (seismic velocities) Structures, faults, depth to bedrock, lithology Surface, borehole, cross-hole/(velocity inversion, ambient vibrations) DC electrical resistivity Electrical resistivity Water content, salinity, pore fluid, temperature, porosity, lithology Borehole, cross-hole, surface/(impermeable membrane) Induced polarization (IP) Chargeability Disseminated metallic particles (pyrite), clay, surface area, lithology Borehole, cross-hole, surface (noise and inductive coupling) Spontaneous potential (SP) Electrical charges and electrical conductivity Flow in porous media, redox potential Borehole, cross-hole, surface/(electrical noise) Ground Penetrating Radar (GPR) Dielectrical constant and electrical conductivity Structures, faults, water content, salinity, pore fluid, porosity, lithology Borehole, cross-hole, surface/(conductive ground) Electromagnetic (EM) Electrical conductivity and magnetic susceptibility Water content, salinity, pore fluid, porosity, lithology, Ferrous materials Borehole, cross-hole, surface, airborne or ATV mounted/(Metallic external objects) Magnetic Magnetic susceptibility Ferrous materials (buried drums, containers…), lithology Surface/(Metallic external objects) Gravimetry Density Voids, basin-like structures Surface/(corrections, measurement time) Borehole logging (caliper, gamma, sonic, flowmeter, TV) Many Many: fracture locations, clay content, lithology, transmissivity, … Borehole

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Different targets…

A combination of different methods is recommended to reduce uncertainties

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The main phases of a geophysical investigation and associated costs

  • Pre-investigation and

feasibililty

  • Set-up
  • Properties
  • Surveys
  • Measurements on site
  • Data quality control
  • Possible interferences
  • Data processing and

interpretation

  • Image appraisal
  • Complementary data
  • Report synthesis
  • Desk study
  • Equipment preparation and

depreciation

  • Field study
  • Transport to and on site
  • Data acquisition
  • Accomodation
  • Desk study

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A lot of pragmatism too: site access, logistics, near-surface objects (cables etc…)

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Agenda of the presentation

  • A short introduction to geophysics
  • Landfill investigation
  • Context
  • Extension
  • Composition
  • Landfill monitoring
  • Take home message
  • Landfill of Onoz

19 RAWFILL

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Applied geophysics and landfills

100 200 300 400 500 600 1960 1970 1980 1990 2000 2010 2020

Scopus # with landfill* AND geophysic*

Whitley and Jewel, 1992 Feasibility Green et al., 1999 Multi-method De Laco et al., 2003 Multi-scale Grellier et al., 2007, Focus on DC resistivity Clément et al., 2010 Monitoring Dedicated development (e.g. Audebert et al., 2014; Konstantaki et al., 2016; Dumont et al., 2016; van de Vijver 2017) Book chapter by Soupios and Ntarlagiannis (2017)

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Query performed 03/02/2018: (TITLE-ABS-KEY(landfill* AND geophysic*))

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Europe leads the way!

20 40 60 80 100 120 140 160 180 200

Scopus # per geographical area

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Physical properties of wastes: solid part

Dumont (2017)

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Physical properties of wastes: liquid part

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Physical properties of wastes: liquid part

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Physical properties of wastes

Generally, geophysical properties contrast well with the surrounding environment

  • Leachate ionic strength and temperature increase > low

electrical resistivity (0.5-30 m)

  • Metal scraps and redox reactions > high chargeability and self-

potential (100s mV/V, 100s mV)

  • Ferromagnetic objects >  2-4 orders of magnitude larger than

sedimentary rocks

  • Low compaction > lower density 1-2 t/m3 and lower elastic

moduli (Vp~180 m/s to 1450m/s)

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Agenda of the presentation

  • A short introduction to geophysics
  • Landfill investigation
  • Context
  • Extension
  • Composition
  • Landfill monitoring
  • Take home message
  • Landfill of Onoz

26 RAWFILL

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Landfill investigation: extension

Van de Vijver PhD, 2017

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loamy sandy soil background Average driving speed 7.3 km/h

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Agenda of the presentation

  • A short introduction to geophysics
  • Landfill investigation
  • Context
  • Extension
  • Composition
  • Landfill monitoring
  • Take home message
  • Landfill of Onoz

28 RAWFILL

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Landfill investigation: Composition

Towards quantitatvie spatial distribution of leachate property : petrophysics

(Dumont et al., 2016)

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ρb = 1.53 ∗ 0,40 ∗ θ𝑤

−2.101

σ𝑈 σ25 = 0.19 T − 25 + 1

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Landfill investigation: Composition

  • Towards quantitative spatial distribution of leachate property

ρb = 1.53 ∗ 0,40 ∗ θ𝑤

−2.101

σ𝑈 σ25 = 0.19 T − 25 + 1

(Dumont et al., 2016)

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Agenda of the presentation

  • A short introduction to geophysics
  • Landfill investigation
  • Context
  • Extension
  • Composition
  • Landfill monitoring
  • Take home message
  • Landfill of Onoz

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Landfill monitoring

Injection trench (Audebert et al., 2014)

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Les Champs-Jouault experimental site

  • Household waste, non-hazardous

industrial waste

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Landfill monitoring

(Audebert et al., 2014; 2016)

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Agenda of the presentation

  • A short introduction to geophysics
  • Landfill investigation
  • Context
  • Extension
  • Composition
  • Landfill monitoring
  • Take home message
  • Landfill of Onoz

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Take home message

  • Not a silver bullet (no universal response), it needs to be assisted by

complementary data

  • Go/No go pre-feasibility using pre-modeling should be standard

procedure On landfills :

  • Landfills Hor./Vert. delimitation is demonstrated > multi-methods very

efficient

  • For composition quantification: requires careful and dedicated

processing and laboratory petrophysics

  • Geophysical monitoring can follow leachate injection, membrane

leaking

  • To follow biodegradation is more challenging in the long term

35 RAWFILL

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Agenda of the presentation

  • A short introduction to geophysics
  • Landfill investigation
  • Context
  • Extension
  • Composition
  • Landfill monitoring
  • Take home message
  • Landfill of Onoz

36 RAWFILL

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Site overview

1971 1976 2000 2009

History:

  • 1902-1967: Quarry, limestone

extraction

  • 1967-1976: Deposit ashes &

lime

  • 1982-1987: waste from

construction sector, tyres, rubber...

  • 2004: 750t of tires removed by

SPAQuE

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Today…

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Site description

Site elevation

  • 20 m of ashes in the upper part
  • 4-? m of waste + lime in the bottom part
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  • 1. Estimate extension and boundaries of the waste
  • 2. Identify ashes and lime
  • 3. Leachate?

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Goal of the first survey:

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Methods – Survey design

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Mapping methods:

  • Electromagnetic survey (EM)

Profiling methods

  • ERT/ IP

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EM survey ERT/ IP

Fieldwork done - covering

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Results EM

Conductivity

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P1 P2

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Results ERT/IP

S N

P1

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Results ERT/IP

S N

P2

P1 P2

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  • The lateral extent of the zone containing the ashes is

clearly visible in the EM images

  • ERT models allow to clearly highlight the boundary

between the limestone bedrock characterized with high electrical resistivity and the lime/waste deposits. The depth of lime lenses still need to be check

Preliminary conclusions

To be confirmed by boreholes/trenches

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