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WE MAKE THE LANDFILL TRANSPARENT

Development of a step by step geo-electrical methodology for landfill investigation

Håkan Rosqvist, Rosqvist Resurs

Torleif Dahlin and Virginie Leroux, Lund University,Mats Svensson, Sara Johansson, Carl-Henrik Månsson Magnus Lindsjö, Tyréns, Sweden

Workshop Malmö 16–17 February 2012

MaLaGa

Objective

To summarize the outcome of several years of research and development in geo-electrical measurements, and to develop a methodology for landfill investigations.

Time and cost effective methodology

MaLaGa

The step by step methodology is based on

1. Electromagnetic conductivity meter – CMD (Stångslingram)

2. Resistivity – Large scale 3. Resistivity – small scale

Measurements in 2010 and 2011 at Filborna landfill site, Helsingborg, Sweden.

Background map – Filborna landfill

A - Final soil cover

B – Old road partly filled with inert waste

C – Intermediate soil cover

• 1950 – 2008• Depth – 40-45 m• Area – 35 Ha• 11 Mton of waste

Electromagnetic conductivity meter - CMD 4/6

CMD 4

CMD 6

Large scale resistivity

2D set-up for measurements in 11 lines

The ABEM Lund Imaging System (Dahlin, 1996)

Large scale measurements - Large scale features

Bedrock

Erosion valley (old river)

High resistivity near surface

Parts with low resistivity in the landfill at depths

Fence diagram

3D Resistivity Mapping

3D Resistivity Mapping

3D IP Mapping

• ABEM Terrameter LS• 3 x ABEM Electrode Selector

ES10-64C• Lightning protection• Mobile internet modem / router• PC for fast data transfer / back-up • Mains power supply

• Stainless steel rod or plate electrodes

• Electrode cables w. pig-tail take-outs

• Water-protected connections

Small scale data acquisition system – 3D

Monitoring Layout Filborna 2011

Small scale

Area for measurements – 22 by 40 meter

Homogeneous resistivity distribution

Small variations over time

Resistivity distribution

Small scale – 3D

Background information

Various historical geo-information

Old photos

Organic waste

Wall – waste/clay

Soil cover

Saturated

Unsaturated

Area with old ”biocells” – some features

Aftonbladet 3 juli 2011

Köpenhamn lamslogs av åskovädret

Jättehagel, kaskadregn och tusentals blixtnedslag. Köpenhamn lamslogs när vädrets makter tog över staden.

Sent i natt hade DMI räknat till 5 309 blixtnedslag och 150 millimeter regn i Köpenhamn med omnejd, enligt danska tidningar.

BILDEXTRA Kaos efter åskoväder Strömavbrott och översvämningar

July 2 - Thunderstorm

Water infiltration after heavy rainfall

Decrease in resistivityIsosurface showing a -6% change

6 hours between measurements

Zone with water infiltration correlated to the wall?

Water infiltration after heavy rainfall

Zone with variability in resistivity

Next step

Validation of the results from the geo-electrical measurements by field sampling and other physical investigations.

Thank you for your attention!

hakan@rosqvist-resurs.se

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