Technology:
Barometrically Enhanced Remediation Technology (BERT™)
- BERT consists of a large surface area seal, a collection plenum, and a one-way valve to vent soil gas to the atmosphere at a low rate; the system operation relies on small changes in atmospheric pressure and wind effects to displace soil gas
- The system at INEEL used a surface seal 100 ft by 100 ft made of 45-mil EPDM, a collection plenum filled with ¼ to ½ inch pea gravel that was 10 ft thick and 30 ft diameter, and a vent pipe 6 ft tall
- In October 1996 (after almost 2 years of operation), the system was modified to extend the collection plenum to the edges of the surface seal to expose more soil; this was referred to as the wind-enhanced configuration
- No boreholes or site electrical power was used in the demonstration
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Cleanup Authority:
Not identified
Technical Contacts:
William E. Lowry
Science and Engineering Associates, Inc.
(505) 424-6955
E-mail: blowry@seabase.com
Eric Miller
Lockheed Martin
Idaho Technologies Company
(208) 526-9410
E-mail: ecm@inel.gov | Management Contacts:
William Haslebacher
Federal Energy Technology Center
(304) 285-5435
E-mail: whasle@fetc.doe.gov |
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Contaminants:
Chlorinated solvents
- Maximum concentration of carbon tetrachloride was 111 ppm |
Waste Source:
Waste burial pit |
Type/Quantity of Media Treated:
Soil (in situ)
- Surface soils are typically less than 20 ft thick and consist of gravelly sand and fine-grained eolian deposits; water table is 600 ft bgs |
Purpose/Significance of Application:
Demonstrate use of passive soil venting for remediation of VOC-contamination |
Regulatory Requirements/Cleanup Goals:
- Objectives of demonstration were to obtain technical and cost information about BERT™
- No specific cleanup goals were identified |
Results:
- During the initial phase of the demonstration, the average vent flow rate was 9 m3/day, with contaminants removed as follows: TCE - 27.8 ppm and 1.15 g/day, CCl4 - 5.2 ppm and 0.25 g/day, and chloroform - 19.6 ppm and 0.73 g/day
- During the wind-enhanced phase of the demonstration, the average vent flow rate was 34 m3/day, with contaminants removed as follows: TCE - 18.9 ppm and 2.9 g/day, CCl4 - 6.8 ppm and 1.2 g/day, and chloroform - 9.4 ppm and 1.3 g/day
- Results showed that wind speed had a greater effect on vent flow than did changes (drop) in atmospheric pressure |
Cost Factors:
- Projected costs for a full-scale application of BERT™ were $67,860 total, including materials, labor, and O&M, or $100/yd3 ($74/ton)
- Unit costs for BERT™ were compared with costs for landfill disposal ($320/yd3, $237/ton), soil vapor extraction ($183/yd3, $136/ton), and thermal desorption ($360/yd3, $267/ton), and found to be lower on both a per cubic yard and per ton basis |
Description:
The Idaho National Engineering and Environmental Laboratory (INEEL) Radioactive Waste Management Complex (RWMC) contains a Subsurface Disposal Area (SDA). The SDA is a 96 acre fenced disposal area where mixed wastes containing VOCs and radioactive wastes were buried in shallow waste disposal pits, trenches, and soil vault rows. Disposal pit 2 at the SDA received barrels of sludge between 1954 and 1965. The primary contaminant in this area was chlorinated solvents.
The Barometrically Enhanced Remediation Technology (BERT™) was demonstrated at this site. BERT™ induces net upward displacement of soil gas based on small changes in atmospheric pressure and wind speed. A system was demonstrated that was 100 ft long by 100 ft wide, and that required no boreholes or site power. During the initial phase of the demonstration, the average vent flow rate was 9 m3/day, with removals of TCE, CCl4, and chloroform ranging from 0.25 to 1.15 g/day. During the wind-enhanced phase of the demonstration, the average vent flow rate was 34 m3/day, with removals of TCE, CCl4, and chloroform ranging from 1.2 to 2.9 g/day. Results showed that wind speed had a greater effect on vent flow than changes/drops in atmospheric pressure. Unit costs for BERT™ were compared with costs for landfill disposal, soil vapor extraction, and thermal desorption, and found to be lower on both a per cubic yard and per ton basis. A BERT™ system is currently under construction at Los Alamos National Laboratory, with operation anticipated by the end of July 1999. |
