Description
Historical activity that resulted
in contamination.
| PCE drycleaning operations were conducted at this facility from May of 1990 until 2006. The facility was located in a strip mall in a mixed commercial/residential setting. In 2009, the strip mall was razed.
The contaminant source area at the site was the soil beneath the facility floor slab in the vicinity of the drycleaning machine. Remediation Status: In groundwater monitoring |
Contaminants
Contaminants present and the highest amount
detected in both soil and groundwater.
| Contaminant |
Media |
Concentration (ppb) |
Nondetect |
| cis-1,2-Dichloroethene |
groundwater |
|
|
| Tetrachloroethene (PCE) |
groundwater |
|
|
| Tetrachloroethene (PCE) |
soil |
|
|
| Trichloroethene (TCE) |
groundwater |
|
|
Site Hydrology
| Deepest Significant
Groundwater Contamination: |
|
15ft bgs |
| Plume Size: |
|
Plume Length: 80ft
Plume Width: 50ft
Plume Thickness: 10ft |
| Average Depth
to Groundwater: |
|
6.63ft |
Lithology and Subsurface Geology
|
|
fine-grained sand
Depth: 0-14ft bgs
14ft thick
Conductivity: 8.85ft/day
Gradient: 0.0025ft/ft
|
|
|
fine-grained sand stone
Depth: 14-20ft bgs
6ft thick
|
|
|
fine-grained sand
Depth: 20-32ft bgs
12ft thick
|
|
|
clay
Depth: 32-40ft bgs
8ft thick
|
|
|
silty, fine-grained sand
Depth: 40-50ft bgs
10ft thick
|
|
|
marl with shells
Depth: 52-56ft bgs
4ft thick
|
Pathways and DNAPL Presence
 Groundwater
 Sediments
Soil
DNAPL Present
|
Vapor Intrusion Pathway
Has the potential for vapor intrusion (VI) been evaluated? |
|
No
|
Has a vapor mitigation system been installed? |
|
Yes |
Type of Vapor Mitigation System(s): |
|
Passive Venting
Soil Vapor Extraction
|
Remediation Scenario
Cleanup
Goals: |
|
Soil: PCE = 30 ug/kg (leaching)
Groundwater: PCE = 3 ug/l; TCE = 3 ug/l; cis 1,2-DCE = 70 ug/l
|
Remedy Level: |
|
Full Scale Remedy |
Technologies
In Situ Soil Vapor Extraction |
|
Why the technology was selected:
Soil vapor extraction was selected because it is an effective technology for remediating VOCs in permeable unsaturated sediments.
Date implemented:
Soil Vapor Extraction: September 19, 2000
Final remediation design:
The soil vapor extraction system consisted of two horizontal vapor extraction wells installed at depths of 4 feet and 5.5 feet below grade. The laterals were 55 feet long and were installed from outside the back door of the facility to approximatley the middle of bay that housed the drycleaning operation. The system was powered by a 7.5 HP Rotron regenerative blower. Off gas was treated via two 200 lb. G.A.C. vessels. Design flow rate was 125 cfm under an operating vacuum of 101 inches w.c.
The SVE system was converted to passive venting in August of 2006. The SVE system influent piping was connected to a 4-inch PVC vertical vent stack, 18.5 feet in length. A vent turbine was mounted on the top of the piping, approximately 2.5 feet above the roofline of the building.
Results to date:
The soil vapor extraction system was shut down on in November 2001 and was converted to passive venting (with wind turbines) in February 2004. The passive venting system was shut down in 2009 prior to the strip mall being razed.
The nano-scale zero valent iron injection was conducted in August 2006. The site was in post-active remedial groundwater monitoring from late 2006 until early 2011.
The last two groundwater monitoring events conducted at the site had not found any detections of contaminants in groundwater.
Next Steps:
A Site Rehabilitation Completion Order was issued for this site on November 7, 2011.
Cost to Design and Implement:
All technologies: Design: $17,200
Implementation: $114,800
|
In Situ Zero Valent Iron |
|
Why the technology was selected:
Nano-scale zero valent iron was used to polish low concentrations of contaminants in the groundwater.
Date implemented:
Nano-scale Zero Valent Iron: August 23, 2006
Final remediation design:
The nano-scale zero valent iron injection was conducted on August 23, 2006. Injection was via eight (8) 2-inch diameter injection wells, screened 5-15 ft BLS. A total of 6,715 gallons of 0.88 g/L nanno-scale zero valent iron slurry or approximatley 50 lbs. of NZVI was injected into the eight injection wells at a rate varying from 2-7 gpm. This amounted to 574 - 978 gallons of slurry per well. Following injection of the slurry, each well was flushed with 100 gallons of water to clear the well screens.
Results to date:
The soil vapor extraction system was shut down on in November 2001 and was converted to passive venting (with wind turbines) in February 2004. The passive venting system was shut down in 2009 prior to the strip mall being razed.
The nano-scale zero valent iron injection was conducted in August 2006. The site was in post-active remedial groundwater monitoring from late 2006 until early 2011.
The last two groundwater monitoring events conducted at the site had not found any detections of contaminants in groundwater.
Next Steps:
A Site Rehabilitation Completion Order was issued for this site on November 7, 2011.
Cost to Design and Implement:
All technologies: Design: $17,200
Implementation: $114,800
|
Ex Situ Carbon Adsorption |
|
Date implemented:
Soil Vapor Extraction: September 19, 2000
Final remediation design:
The soil vapor extraction system consisted of two horizontal vapor extraction wells installed at depths of 4 feet and 5.5 feet below grade. The laterals were 55 feet long and were installed from outside the back door of the facility to approximatley the middle of bay that housed the drycleaning operation. The system was powered by a 7.5 HP Rotron regenerative blower. Off gas was treated via two 200 lb. G.A.C. vessels. Design flow rate was 125 cfm under an operating vacuum of 101 inches w.c.
The SVE system was converted to passive venting in August of 2006. The SVE system influent piping was connected to a 4-inch PVC vertical vent stack, 18.5 feet in length. A vent turbine was mounted on the top of the piping, approximately 2.5 feet above the roofline of the building.
Results to date:
The soil vapor extraction system was shut down on in November 2001 and was converted to passive venting (with wind turbines) in February 2004. The passive venting system was shut down in 2009 prior to the strip mall being razed.
The nano-scale zero valent iron injection was conducted in August 2006. The site was in post-active remedial groundwater monitoring from late 2006 until early 2011.
The last two groundwater monitoring events conducted at the site had not found any detections of contaminants in groundwater.
Next Steps:
A Site Rehabilitation Completion Order was issued for this site on November 7, 2011.
Cost to Design and Implement:
All technologies: Design: $17,200
Implementation: $114,800
|
In Situ Other |
|
Why the technology was selected:
Passive venting was utilized after operation of the soil vapor extraction to address low-level concentrations of VOCs in the unsaturated zone.
Date implemented:
Passive Venting: February 17, 2004
Final remediation design:
The soil vapor extraction system consisted of two horizontal vapor extraction wells installed at depths of 4 feet and 5.5 feet below grade. The laterals were 55 feet long and were installed from outside the back door of the facility to approximatley the middle of bay that housed the drycleaning operation. The system was powered by a 7.5 HP Rotron regenerative blower. Off gas was treated via two 200 lb. G.A.C. vessels. Design flow rate was 125 cfm under an operating vacuum of 101 inches w.c.
The SVE system was converted to passive venting in August of 2006. The SVE system influent piping was connected to a 4-inch PVC vertical vent stack, 18.5 feet in length. A vent turbine was mounted on the top of the piping, approximately 2.5 feet above the roofline of the building.
Other technologies used:
passive venting
Results to date:
The soil vapor extraction system was shut down on in November 2001 and was converted to passive venting (with wind turbines) in February 2004. The passive venting system was shut down in 2009 prior to the strip mall being razed.
The nano-scale zero valent iron injection was conducted in August 2006. The site was in post-active remedial groundwater monitoring from late 2006 until early 2011.
The last two groundwater monitoring events conducted at the site had not found any detections of contaminants in groundwater.
Next Steps:
A Site Rehabilitation Completion Order was issued for this site on November 7, 2011.
Cost to Design and Implement:
All technologies: Design: $17,200
Implementation: $114,800
|
Costs
Cost
for Assessment:
|
|
$53,800 |
Cost
for Operation and Maintenance:
|
|
O&M: $58,800
Monitoring: $63,000 |
Total
Costs for Cleanup:
|
|
$353,500 |
Lessons Learned
|
Little change in groundwater contaminant concentrations was observed after the nanno-scale zero valent iron injection. It was not effective as a polishing low concentrations of contaminants in groundwater.
|
Contacts
Aaron Cohen
Florida Dept. of Environmental Protection
Bureau of Waste Cleanup, MS 4500
2600 Blair Stone Road
Tallahassee, Florida 32399
850-245-8974
Aaron.Cohen@dep.state.fl.us
Kelly Baltz, P.E.
Golder Associates, Inc.
9428 Baymeadows Road, Suite 400
Jacksonville, Florida 32256
Phone: (904) 421-4207
E-mail: Kelly_Baltz@Golder.com
|
Site Specific References
Site Assessment Report: April 1999
Remedial Action Plan: February 2000
Construction Completion Report: October 2000
Operation & maintenance reports: 2000 - 2001
Groundwater Monitoring Reports: 2001 - 2011.
|
|
