Cost-effective exploration methods for landfills: results from the RAWFILL project Fred Nguyen, David Caterina, Itzel Manrique Isunza, Tom Debouny 1
Cost-effective exploration methods for landfills:
results from the RAWFILL projectFred Nguyen, David Caterina, Itzel Manrique Isunza,
Tom Debouny
1
Agenda of the presentation
• A short introduction to geophysics
• Landfill investigation
• Take home message
2
Applied geophysics: a means to see through
3
Electrical resistivity tomography principles
4
Agenda of the presentation
• A short introduction to geophysics
• Case study from RAWFILL• Site presentation
• Results
• Model
• Take home message
5
RAWFILL 6
Onoz case study
Landfills investigated in RAWFILL
Context: history
7
1963 1971 1976
ashes
2018
(SPW, 2019)
1902-1967: quarry (limestone extraction)
1967-1976: slaked lime deposits followed by ashes
deposits
1982-1987: heterogeneous wastes (inert, tires,
rubber, plastic, car parts, household...)
RAWFILL 8
Site conceptual model
9
• Electromagnetic induction (EM)
• Magnetometry (MAG)
• Electrical Resistivity Tomography (ERT) and Induced Polarization (IP)
• Seismic method
– Horizontal to Vertical Noise Spectral Ratio (HVNSR or H/V)
RAWFILL
Mapping
Sounding
Imaging
Selected geophysics
Agenda of the presentation
• A short introduction to geophysics
• Case study from RAWFILL• Site presentation
• Results
• Model
• Take home message
10
RAWFILL 11
EM
Coverage and EMI result
RAWFILL 12
Interpretation: EM
20181976
N
RAWFILL 13
MAG
Coverage and magnetometry result
RAWFILL 14
ERT/IP
ERT lines
Tomography (resistivity and induced polarization)
RAWFILL 15
P1
Limestone bedrock??Fracturedbedrock
LimeLime
??
Waste
Electrical resistivity
Metallic scraps
Chargeability
ERT/IP
Electrical resistivity tomography result
RAWFILL 16
Sampling
P2
Electrical resistivity tomography vs validation
RAWFILL 17
(Debouny, 2019)
Bedrock
Lime
Grey
ashes
H/V measurement Borehole log
𝑓𝑎𝑠ℎ𝑒𝑠
𝑓𝑙𝑖𝑚𝑒
𝑉𝑠𝑙𝑖𝑚𝑒 = 318𝑚
𝑠𝑉𝑠𝑎𝑠ℎ𝑒𝑠 = 271
𝑚
𝑠
Possible to estimate the thickness of ash and lime at other HV stations
Using the resonance frequency to sound
RAWFILL 18
N
From 2D to 3D tomography
Agenda of the presentation
• A short introduction to geophysics
• Case study from RAWFILL• Site presentation
• Results
• Model
• Take home message
19
RAWFILL 20
Translation in a quantified model
Take home messageCase successful here but not a silver bullet (no universal response), it needs to be assisted by complementary data
Landfills Hor./Vert. delimitation is demonstrated > multi-methods very efficient
For composition quantification: requires careful and dedicated processingand laboratory petrophysics
Outlook: Geophysical monitoring to follow leachate injection, membrane leaking , biodegradation/bioleaching
21
Thank you
22
23