Ennovo were engaged to undertake investigations into high carbon monoxide concentrations being recorded from numerous extraction wells at a large landfill. The investigation undertaken was to determine if sub-surface oxidation (SSO) was occurring, the exact location and potential mitigation strategies.
Thermocouples were temporarily installed in identified extraction wells to identify any “hot spots” and the potential scale an intensity of the SSO activity. Upon identification of the location of the SSO activity, permanent thermocouples and gas monitors were installed at varying depths within wells to monitor temperature and gas composition changes over time.
It was identified that there was SSO activity occurring at relatively deep levels with minor changes to temperature occurring over a number of months. The decision was made to continue monitoring temperature and gas composition, with a focus on identifying changes and implementing rectification actions as required.
Specific activities included the following:
- Sub-surface oxidation (SSO) investigation
- Thermocouple installation and logging
- LFG monitoring
- Data management and reporting