Remediation – Michigan Department of Transportation (MDOT)
Global was contracted by the Michigan Department of Transportation (MDOT) to extract naturally occurring methane from groundwater. As part of the 8 Mile Road improvement project, four-foot diameter caissons were being constructed below ground. The methane was initially discovered during their construction. Naturally occurring methane was present in the groundwater, which threatened to jeopardize the integrity of the concrete.
Global installed wells into the water table on either side of the caisson in order to vent the methane under vacuum. Once under vacuum, levels in the caisson were monitored until the levels reached appropriate concrete pouring parameters. Monitoring of the lower explosive limit (LEL) was conducted onsite to ensure a safe working environment.
The system was operated for 10-12 hour shifts, with the vacuum operating for 24 hours a day, 7 days a week for approximately one month. During operation, Global monitored methane levels in the water wells and the vacuum trailer discharge.