Description
Historical activity that resulted
in contamination.
| Springvilla Dry Cleaners (SDC) operated in a shopping center complex from the 1960s to 2000. SDC was a coin-operated/self-serve drycleaning operation. Spent solvent apparently was discharged to the sanitary sewer, which leaked and resulted in PCE being discharged to the soil and groundwater beneath the building.
The cleaners was located in a shopping center adjacent to other commercial shops and a large supermarket. Surrounding the shopping center is other commercial development, and some residential (apartments). downgradient of the site is a neighborhood of single family homes, some with backyard irrigation wells.
The site is located within the modeled capture zone for the local water utility's water supply wells. The site is a high priority because of possible impacts to the municipal water well and other downgradient residential well users. Remediation Status: In groundwater monitoring |
Contaminants
Contaminants present and the highest amount
detected in both soil and groundwater.
| Contaminant |
Media |
Concentration (ppb) |
Nondetect |
| Tetrachloroethene (PCE) |
groundwater |
79,000 ppb |
|
| Tetrachloroethene (PCE) |
soil |
130,000 ppb |
|
| Trichloroethene (TCE) |
groundwater |
96 ppb |
|
| Trichloroethene (TCE) |
soil |
39 ppb |
|
Site Hydrology
| Deepest Significant
Groundwater Contamination: |
|
60ft bgs |
| Plume Size: |
|
Plume Length: 1,000ft
Plume Width: 500ft
Plume Thickness: 60ft |
| Average Depth
to Groundwater: |
|
10ft |
Lithology and Subsurface Geology
|
|
Silty and clayey sand
Depth: 0-10ft bgs
10ft thick
Conductivity: 0.004ft/day
Gradient: 0.005ft/ft
|
|
|
Gravel with sand and silt
Depth: 10ft bgs
|
Pathways and DNAPL Presence
 Groundwater
 Sediments
Soil
Presumptive Evidence of DNAPL
|
Remediation Scenario
Cleanup
Goals: |
|
Reduce souce concentrations to effect reduction in groundwater contamination both on and off site, and reduce the potential for volatilization to indoor air spaces.
|
Technologies
In Situ Bioremediation |
|
Why the technology was selected:
Soil Excavation: Building owner's willingness to demolish part of the building provided the opportunity to access and remove source beneath building. On-Site Soil Treatment (SVE): Space and time allowable. Used RCRA Contained-In rule to delist and dispose treated soil at lower cost than RCRA listed waste. Chemical Oxidation (permanganate): Excavation allowed installation of infiltration gallery, and the cost of materials was relatively low. Thes factors combined to allow additional treatment of residual soil and source area groundwater contamination near the source following soil excavation.
Date implemented:
September 2004: soil removal and ex-situ SVE treatment of soil
September 2004: 1st Na Permanganate treatment
October 2005: 2nd Na Permanganate treatment
Final remediation design:
1) Building partially demolished temporarily and shored for access.
2) Begining 8/31/04 excavated 150 yards3 of contaminated soil from source zone.
3)Constructed on-site treatment cell using SVE with carbon treatment of vapor effluent.
4) Installed deep (infiltration) and shallow (vapor recovery) slotted piping in excavation before and during backfilling.
5) Building partially reconstructed by owner.
6) In October 2004, 1,100 gallons of 4% sodium permanganate solution injected through lower infiltration piping in source are excavation.
8) In October 2005, implemented the second sodium permanganate injection.
9) Sept 2007-Aug 2009: Operated groundwater bioremediation system consisting of extraction and reinjection wells in shallow and intermediate depths of the aquifer. Boistimulation ammendments used included dextrose, nutrients, ethyl lactate, emulsified vegetable oil.
10) August 2009: Injected emulsified vegetable oil through 16 push probes into shallow aquifer beneath supermarket building to affect cleanup and reduce threat of indoor air vapor intrusion.
Other technologies used:
Sub Slab: Active vapor recovery with low-pressure radon technology vacuum pump installed beneath the building concrete slab was done prior to the soil removal to vent PCE vapors and reduce indoor air migration.
Results to date:
In most monitoring wells there has been complete or nearly complete reduction of PCE and TCE with relatively minor persistence of other reductive daughter products. The shallow well immediately downgradient of the building has seen some rebound to 500 ug/L PCE. Downgradient of that well, the intermediate well has also seen rebound to 470 ug/L PCE.
Next Steps:
1)Performance groundwater monitoirng to determine the need for further bioremediation.
2)Complete off-site delineation and risk assessment.
Cost to Design and Implement:
$450,000 (all technologies)
|
In Situ Chemical Oxidation |
|
Why the technology was selected:
Soil Excavation: Building owner's willingness to demolish part of the building provided the opportunity to access and remove source beneath building. On-Site Soil Treatment (SVE): Space and time allowable. Used RCRA Contained-In rule to delist and dispose treated soil at lower cost than RCRA listed waste. Chemical Oxidation (permanganate): Excavation allowed installation of infiltration gallery, and the cost of materials was relatively low. Thes factors combined to allow additional treatment of residual soil and source area groundwater contamination near the source following soil excavation.
Date implemented:
September 2004: soil removal and ex-situ SVE treatment of soil
September 2004: 1st Na Permanganate treatment
October 2005: 2nd Na Permanganate treatment
Final remediation design:
1) Building partially demolished temporarily and shored for access.
2) Begining 8/31/04 excavated 150 yards3 of contaminated soil from source zone.
3)Constructed on-site treatment cell using SVE with carbon treatment of vapor effluent.
4) Installed deep (infiltration) and shallow (vapor recovery) slotted piping in excavation before and during backfilling.
5) Building partially reconstructed by owner.
6) In October 2004, 1,100 gallons of 4% sodium permanganate solution injected through lower infiltration piping in source are excavation.
8) In October 2005, implemented the second sodium permanganate injection.
9) Sept 2007-Aug 2009: Operated groundwater bioremediation system consisting of extraction and reinjection wells in shallow and intermediate depths of the aquifer. Boistimulation ammendments used included dextrose, nutrients, ethyl lactate, emulsified vegetable oil.
10) August 2009: Injected emulsified vegetable oil through 16 push probes into shallow aquifer beneath supermarket building to affect cleanup and reduce threat of indoor air vapor intrusion.
Other technologies used:
Sub Slab: Active vapor recovery with low-pressure radon technology vacuum pump installed beneath the building concrete slab was done prior to the soil removal to vent PCE vapors and reduce indoor air migration.
Results to date:
In most monitoring wells there has been complete or nearly complete reduction of PCE and TCE with relatively minor persistence of other reductive daughter products. The shallow well immediately downgradient of the building has seen some rebound to 500 ug/L PCE. Downgradient of that well, the intermediate well has also seen rebound to 470 ug/L PCE.
Next Steps:
1)Performance groundwater monitoirng to determine the need for further bioremediation.
2)Complete off-site delineation and risk assessment.
Cost to Design and Implement:
$450,000 (all technologies)
|
Ex Situ Chemical Oxidation |
|
Why the technology was selected:
Soil Excavation: Building owner's willingness to demolish part of the building provided the opportunity to access and remove source beneath building. On-Site Soil Treatment (SVE): Space and time allowable. Used RCRA Contained-In rule to delist and dispose treated soil at lower cost than RCRA listed waste. Chemical Oxidation (permanganate): Excavation allowed installation of infiltration gallery, and the cost of materials was relatively low. Thes factors combined to allow additional treatment of residual soil and source area groundwater contamination near the source following soil excavation.
Date implemented:
September 2004: soil removal and ex-situ SVE treatment of soil
September 2004: 1st Na Permanganate treatment
October 2005: 2nd Na Permanganate treatment
Final remediation design:
1) Building partially demolished temporarily and shored for access.
2) Begining 8/31/04 excavated 150 yards3 of contaminated soil from source zone.
3)Constructed on-site treatment cell using SVE with carbon treatment of vapor effluent.
4) Installed deep (infiltration) and shallow (vapor recovery) slotted piping in excavation before and during backfilling.
5) Building partially reconstructed by owner.
6) In October 2004, 1,100 gallons of 4% sodium permanganate solution injected through lower infiltration piping in source are excavation.
8) In October 2005, implemented the second sodium permanganate injection.
9) Sept 2007-Aug 2009: Operated groundwater bioremediation system consisting of extraction and reinjection wells in shallow and intermediate depths of the aquifer. Boistimulation ammendments used included dextrose, nutrients, ethyl lactate, emulsified vegetable oil.
10) August 2009: Injected emulsified vegetable oil through 16 push probes into shallow aquifer beneath supermarket building to affect cleanup and reduce threat of indoor air vapor intrusion.
Other technologies used:
Sub Slab: Active vapor recovery with low-pressure radon technology vacuum pump installed beneath the building concrete slab was done prior to the soil removal to vent PCE vapors and reduce indoor air migration.
Results to date:
In most monitoring wells there has been complete or nearly complete reduction of PCE and TCE with relatively minor persistence of other reductive daughter products. The shallow well immediately downgradient of the building has seen some rebound to 500 ug/L PCE. Downgradient of that well, the intermediate well has also seen rebound to 470 ug/L PCE.
Next Steps:
1)Performance groundwater monitoirng to determine the need for further bioremediation.
2)Complete off-site delineation and risk assessment.
Cost to Design and Implement:
$450,000 (all technologies)
|
Ex Situ Soil Removal |
|
Why the technology was selected:
Soil Excavation: Building owner's willingness to demolish part of the building provided the opportunity to access and remove source beneath building. On-Site Soil Treatment (SVE): Space and time allowable. Used RCRA Contained-In rule to delist and dispose treated soil at lower cost than RCRA listed waste. Chemical Oxidation (permanganate): Excavation allowed installation of infiltration gallery, and the cost of materials was relatively low. Thes factors combined to allow additional treatment of residual soil and source area groundwater contamination near the source following soil excavation.
Date implemented:
September 2004: soil removal and ex-situ SVE treatment of soil
September 2004: 1st Na Permanganate treatment
October 2005: 2nd Na Permanganate treatment
Final remediation design:
1) Building partially demolished temporarily and shored for access.
2) Begining 8/31/04 excavated 150 yards3 of contaminated soil from source zone.
3)Constructed on-site treatment cell using SVE with carbon treatment of vapor effluent.
4) Installed deep (infiltration) and shallow (vapor recovery) slotted piping in excavation before and during backfilling.
5) Building partially reconstructed by owner.
6) In October 2004, 1,100 gallons of 4% sodium permanganate solution injected through lower infiltration piping in source are excavation.
8) In October 2005, implemented the second sodium permanganate injection.
9) Sept 2007-Aug 2009: Operated groundwater bioremediation system consisting of extraction and reinjection wells in shallow and intermediate depths of the aquifer. Boistimulation ammendments used included dextrose, nutrients, ethyl lactate, emulsified vegetable oil.
10) August 2009: Injected emulsified vegetable oil through 16 push probes into shallow aquifer beneath supermarket building to affect cleanup and reduce threat of indoor air vapor intrusion.
Other technologies used:
Sub Slab: Active vapor recovery with low-pressure radon technology vacuum pump installed beneath the building concrete slab was done prior to the soil removal to vent PCE vapors and reduce indoor air migration.
Results to date:
In most monitoring wells there has been complete or nearly complete reduction of PCE and TCE with relatively minor persistence of other reductive daughter products. The shallow well immediately downgradient of the building has seen some rebound to 500 ug/L PCE. Downgradient of that well, the intermediate well has also seen rebound to 470 ug/L PCE.
Next Steps:
1)Performance groundwater monitoirng to determine the need for further bioremediation.
2)Complete off-site delineation and risk assessment.
Cost to Design and Implement:
$450,000 (all technologies)
|
Ex Situ Soil Vapor Extraction |
|
Why the technology was selected:
Soil Excavation: Building owner's willingness to demolish part of the building provided the opportunity to access and remove source beneath building. On-Site Soil Treatment (SVE): Space and time allowable. Used RCRA Contained-In rule to delist and dispose treated soil at lower cost than RCRA listed waste. Chemical Oxidation (permanganate): Excavation allowed installation of infiltration gallery, and the cost of materials was relatively low. Thes factors combined to allow additional treatment of residual soil and source area groundwater contamination near the source following soil excavation.
Date implemented:
September 2004: soil removal and ex-situ SVE treatment of soil
September 2004: 1st Na Permanganate treatment
October 2005: 2nd Na Permanganate treatment
Final remediation design:
1) Building partially demolished temporarily and shored for access.
2) Begining 8/31/04 excavated 150 yards3 of contaminated soil from source zone.
3)Constructed on-site treatment cell using SVE with carbon treatment of vapor effluent.
4) Installed deep (infiltration) and shallow (vapor recovery) slotted piping in excavation before and during backfilling.
5) Building partially reconstructed by owner.
6) In October 2004, 1,100 gallons of 4% sodium permanganate solution injected through lower infiltration piping in source are excavation.
8) In October 2005, implemented the second sodium permanganate injection.
9) Sept 2007-Aug 2009: Operated groundwater bioremediation system consisting of extraction and reinjection wells in shallow and intermediate depths of the aquifer. Boistimulation ammendments used included dextrose, nutrients, ethyl lactate, emulsified vegetable oil.
10) August 2009: Injected emulsified vegetable oil through 16 push probes into shallow aquifer beneath supermarket building to affect cleanup and reduce threat of indoor air vapor intrusion.
Other technologies used:
Sub Slab: Active vapor recovery with low-pressure radon technology vacuum pump installed beneath the building concrete slab was done prior to the soil removal to vent PCE vapors and reduce indoor air migration.
Results to date:
In most monitoring wells there has been complete or nearly complete reduction of PCE and TCE with relatively minor persistence of other reductive daughter products. The shallow well immediately downgradient of the building has seen some rebound to 500 ug/L PCE. Downgradient of that well, the intermediate well has also seen rebound to 470 ug/L PCE.
Next Steps:
1)Performance groundwater monitoirng to determine the need for further bioremediation.
2)Complete off-site delineation and risk assessment.
Cost to Design and Implement:
$450,000 (all technologies)
|
Ex Situ Other |
|
Why the technology was selected:
Soil Excavation: Building owner's willingness to demolish part of the building provided the opportunity to access and remove source beneath building. On-Site Soil Treatment (SVE): Space and time allowable. Used RCRA Contained-In rule to delist and dispose treated soil at lower cost than RCRA listed waste. Chemical Oxidation (permanganate): Excavation allowed installation of infiltration gallery, and the cost of materials was relatively low. Thes factors combined to allow additional treatment of residual soil and source area groundwater contamination near the source following soil excavation.
Date implemented:
September 2004: soil removal and ex-situ SVE treatment of soil
September 2004: 1st Na Permanganate treatment
October 2005: 2nd Na Permanganate treatment
Final remediation design:
1) Building partially demolished temporarily and shored for access.
2) Begining 8/31/04 excavated 150 yards3 of contaminated soil from source zone.
3)Constructed on-site treatment cell using SVE with carbon treatment of vapor effluent.
4) Installed deep (infiltration) and shallow (vapor recovery) slotted piping in excavation before and during backfilling.
5) Building partially reconstructed by owner.
6) In October 2004, 1,100 gallons of 4% sodium permanganate solution injected through lower infiltration piping in source are excavation.
8) In October 2005, implemented the second sodium permanganate injection.
9) Sept 2007-Aug 2009: Operated groundwater bioremediation system consisting of extraction and reinjection wells in shallow and intermediate depths of the aquifer. Boistimulation ammendments used included dextrose, nutrients, ethyl lactate, emulsified vegetable oil.
10) August 2009: Injected emulsified vegetable oil through 16 push probes into shallow aquifer beneath supermarket building to affect cleanup and reduce threat of indoor air vapor intrusion.
Other technologies used:
Sub Slab: Active vapor recovery with low-pressure radon technology vacuum pump installed beneath the building concrete slab was done prior to the soil removal to vent PCE vapors and reduce indoor air migration.
Results to date:
In most monitoring wells there has been complete or nearly complete reduction of PCE and TCE with relatively minor persistence of other reductive daughter products. The shallow well immediately downgradient of the building has seen some rebound to 500 ug/L PCE. Downgradient of that well, the intermediate well has also seen rebound to 470 ug/L PCE.
Next Steps:
1)Performance groundwater monitoirng to determine the need for further bioremediation.
2)Complete off-site delineation and risk assessment.
Cost to Design and Implement:
$450,000 (all technologies)
|
Costs
Cost
for Assessment:
|
|
$300,000 |
Cost
for Operation and Maintenance:
|
|
$25,000 per year (monitoring) |
Total
Costs for Cleanup:
|
|
$1,000,000 |
Lessons Learned
1. A cooperative and willing site owner can help facilitate aggressive remediation that directly addresses the source and will likely save a lot of money in the long run.
2. Ex-situ treatment of listed hazardous waste soils is a cost effective alternative to direct removal and landfill disposal.
Bioremediation using a recirculating system of extraction and injection wells can be very beneficial for shortening treatment times and flushing sorbed contaminant mass from the soil matrix.
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Contacts
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