Drycleaner Site Profiles

Town 'N Country Cleaners, Winter Park, Florida

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

checkGroundwater
Sediments
checkSoil
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

Melissa Garvin, Poject Manager
Bureau of Waste Cleanup (MS 4520)
Florida Department of Environmental Protection
2600 Blair Stone Road
Tallahassee, Florida 32399-2400
Phone: (850) 245-8994
E-mail: Melissa.Garvin@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.