Fracture-Emplacement and 3D Mapping of a Micro-Iron/Carbon Amendment in TCE-Impacted Sedimentary Bedrock
Tuesday, May 6, 2014: 2:00 p.m.
Platte River Room (Westin Denver Downtown)
Gordon Bures, M. Eng., P. Eng.
,
TOTERRA Remediation (formerly Frac Rite Environmental Ltd.), Calgary, AB, Canada
Scott Barker, MBA, BScE
,
TOTERRA Remediation, Burlington, ON, Canada
Kent Sorenson, Ph.D., PE
,
Environmental Management Division, CDM Smith, Denver, CO
An in situ
pilot remediation project was carried out on behalf of the U.S. Army Corps of Engineers at the Former Atlas “E” Missile Site No. 12 in Colorado that featured an innovative application of drilling, treatment, fracture-emplacement, and geophysical technologies to mitigate impacts from chlorinated volatile organic hydrocarbons.
The former missile site complex is underlain by silty sandstone bedrock sediments impacted by trichloroethene (TCE) exceeding 3000 μg/L and associated volatile organic hydrocarbons. The purpose of the pilot test was to evaluate the performance of technologies prior to developing the proposed remedy. Two pilot test areas (source area and dissolved plume area) were selected to evaluate the effectiveness of biotic and abiotic in situ chemical reduction for reducing trichloroethene concentrations to less than maximum contaminant levels.
The pilot work involved the emplacement of over 100 tons of a micro-iron/complex carbon treatment amendment into deep bedrock sediments to attain optimal distribution throughout the contaminant plume, including underneath the former Launch and Service Building. Hydraulic fracturing was conducted in pre-drilled boreholes to deliver the amendment slurry between depths of 35 ft. to 63 ft. in bedrock. Tiltmeter geophysics was used to verify the final distribution and geometric configuration of the micro-iron fractures placed. Initial groundwater quality results after the first round of sampling conducted 90 days after EHC placement indicated a reduction in VOCs of 50% to 90% compared to pre-treatment concentrations.
The implications of this demonstrated ability to distribute and map massive quantities of micro-iron amendment in challenging bedrock formations include: a drastic reduction in the amount of injection wells required to treat large plume areas, vastly improved remedial performance monitoring, and significant cost savings compared to conventional remedial approaches.
Gordon Bures, M. Eng., P. Eng., TOTERRA Remediation (formerly Frac Rite Environmental Ltd.), Calgary, AB, Canada
Gordon Bures is a professional engineer and a Principal at TOTERRA Remediation (formerly Frac Rite Environmental Ltd.). He earned a Bachelor of Science degree in Geological Engineering at the University of Manitoba in 1985, and a Master of Environmental Engineering degree at the University of Alberta in 1993.
Scott Barker, MBA, BScE, TOTERRA Remediation, Burlington, ON, Canada
Scott Barker is Vice President, Business Development and a Principal at TOTERRA Remediation, and is based in Burlington, Ontario. He earned a Bachelor of Science degree in Chemical Engineering, with a specialization in Biochemical and Environmental Engineering, at Queen’s University in Kingston, Ontario and a Master of Business Administration Degree at the Ivey School of Business, Western University. Barker has extensive experience in water treatment, chemical formulation, production, and distribution, waste management, and resource recovery.
Kent Sorenson, Ph.D., PE, Environmental Management Division, CDM Smith, Denver, CO
Kent Sorenson is a Senior Vice President of CDM Smith, providing technical expertise in remediation technologies. He has developed and/or demonstrated innovative site characterization and remediation technologies in the U.S., Europe, and Asia, and is a senior technical reviewer for more than 100 government, private, and international sites.
