Hazardous waste landfill, Koelliken

PROJECT

PROJECT	SMDK
LOCATION	KÖLLIKEN (AG) (CH)
DURATION	2005 ‒ 2017

The Kölliken hazardous waste landfill (SMDK) is the largest contaminated site in Switzerland. It is located in the middle of a residential area. It began operation in 1978 and was shut down from 1985 due to odour and dust emissions and made safe for the short term. It transpired that the landfill was threatening the closest water table. The remediation operation, officially approved in 2003, involves creating an appropriate infrastructure (support-free hall, rail connection etc.) and excavating a total of 500,000 tonnes of waste. The work is expected to be completed in 2017.

HIGHLIGHTS

The remediation work is being carried out under the cover of several halls, allowing the landfill body to be dismantled without releasing any emissions. The main supporting structure for the dismantling, processing and storage halls comprises 29 two-hinged arches with tie rods spanning the landfill site lengthwise. The load is transferred to the substrate using reinforced concrete walls and reinforced drilled-in caissons. Prestressed anchors secure the northern slope and Safenwilerstrasse located in the south.
The excavated waste is transported away by rail.
Operation of the protection and maintenance facilities (protection systems, wastewater and waste air processing) are also being continued during the excavation work.

OUR SERVICES

Pedological support services when dismantling the landfill covering and constructing the infra-structure.
Technical support for dealing with contaminated sites when constructing the infrastructure, carrying out material triage and deciding on disposal.
Devising the hydrogeological, geological and geotechnical project bases for the infrastructure.
Monitoring the possible impact of groundwater.
Monitoring geotechnical protection measures using more than 30 inclinometers in the rock and drilled-in caissons, as well as anchor load cells and geodetic measurements.
Taking samples from and assessing the excavation base after excavating hazardous waste, including an assessment of depth contamination.
Devising the disposal concept for stage 2 of the dismantling process.
Analysis and assessment of the noise situation during the various operational phases.