Description
Historical activity that resulted
in contamination.
| A laundry and drycleaning operation operated at the commercial site from at least 1967 until 2000 when the site began to be used exclusively as a laundry until May 2001. Perchloroethylene was used as the drycleaning solvent. The building was built in 1948 and used as a commercial building with an upstairs apartment. The property owner is looking to sell the vacant building and lot after cleanup of the chlorinated solvent release, discovered during a Phase II investigation. Remediation Status: In active remediation |
Contaminants
Contaminants present and the highest amount
detected in both soil and groundwater.
| Contaminant |
Media |
Concentration (ppb) |
Nondetect |
| cis-1,2-Dichloroethene |
groundwater |
6,550 ppb |
|
| Tetrachloroethene (PCE) |
groundwater |
110,000 ppb |
|
| Tetrachloroethene (PCE) |
soil |
4,900,000 ppb |
|
| Trichloroethene (TCE) |
groundwater |
9,200 ppb |
|
| Trichloroethene (TCE) |
soil |
1,500 ppb |
|
| Vinyl Chloride |
groundwater |
100 ppb |
|
Site Hydrology
| Deepest Significant
Groundwater Contamination: |
|
10ft bgs |
| Plume Size: |
|
Plume Length: 110ft
Plume Width: 80ft
Plume Thickness: 30ft |
| Average Depth
to Groundwater: |
|
7ft |
Lithology and Subsurface Geology
|
|
sand and gravel fill beneath concrete or asphalt
Depth: 0-1.5ft bgs
1.5ft thick
Conductivity: 4.14E-013ft/day
|
|
|
clay with trace silt and gravel
Depth: 1.5-30ft bgs
28.5ft thick
Conductivity: 4.14E-013ft/day
Gradient: 0.04ft/ft
|
Pathways and DNAPL Presence
 Groundwater
 Sediments
Soil
DNAPL Present
|
Vapor Intrusion Pathway
Has the potential for vapor intrusion (VI) been evaluated? |
|
Yes
|
How was the site evaluated? |
|
Indoor air sampling
|
Results of VI evaluation: |
|
The VI pathway was ruled out (or does not exist) |
Has a vapor mitigation system been installed? |
|
No |
Additional VI Information: |
|
Vapors in utilities not yet assessed. |
Remediation Scenario
Cleanup
Goals: |
|
Stable to reducing groundwater plume, eliminate hazardous waste soil, eliminate NAPL
|
Remedy Level: |
|
Full Scale Remedy |
Technologies
in Situ Chemical Oxidation |
|
Why the technology was selected:
In-situ chemical oxidation (ISCO) with sodium permanganate solution was selected for inaccessible contaminated soils above hazardous waste levels due to location beneath building and clay.
Date implemented:
December 2004 (Pilot ISCO under 15 psi at 2 gpm),
April 2005 (Portion of full scale (FS) ISCO under 15 psi at 3 gpm),
June 2005 (Remainder of FS ISCO at 3 gpm - FS interrupted to allow for permanganate to react)
June 2006 (Portion of second FS ISCO wit
Final remediation design:
Excavate accessible soil. Characterize pilot injection area by vertically profiling for VOCs in soil and determining existing levels for arsenic, barium, boron, chromium, lithium and strontium in soil and groundwater. Pilot injection area of 10ft x 10ft x 6ft, with five injection points. Volume of sodium permanganate dependent upon natural oxidant demand, porosity and percent reduction desired. 950 gal injected under pressure during pilot. Soil and groundwater sampling approximately four weeks post-pilot injection. Full scale (FS) injection area of 25ft x 10ft x 10ft, with eight additional injection points (13 total). 2,750 gal injected under pressure during FS. Soil and groundwater sampling approximately twelve weeks post-FS injection to allow for complete reaction with permanganate. Quarterly groundwater monitoring post-FS injection. Second FS injection in same area with three additional injection points (16 total). 110 gal injected passively during second FS injection. Performed 10 quarterly post-inj events and 2 SA events.
Additional remedy necessary. Removal of source area beneath building selected.
Results to date:
Pilot ISCO results one month post injection:
Source area soil reduced from 4900 ppm to 2900 ppm.
Source area groundwater reduced from 110 ppm to 1 ppm.
Full scale ISCO results show rebounding PCE (18,900 - 45,000 ppb) with TCE and cis-1,2-DCE showing up at four orders of magnitude above LOD.
Second full scale ISCO results show unstable PCE ranging between 34,000 and 91,000 ppb between 2006 and 2010. TCE decreases from 9,200 to 215 ppb. Cis-1,2-DCE decreases from 4,600 to < 340 ppb. VC < 100 ppb.
Down-gradient well (adj to sewer lateral) unstable to increasing PCE from 330 to 3,300 ppb, TCE unstable between 860 and 62 ppb, cis decreasing from 130 to 15 ppb, VC < 4 ppb.
Next Steps:
ISCO not successful in obtaining goals of stable to reducing plume and NAPL removal. Removal of source area beneath building necessary. Costs for demolition vs. bracing and replacing structure along with excavation being developed.
Cost to Design and Implement:
Excavation, disposal and monitoring $85,000
Pilot & FS ISCO & monitoring $90,105
2nd FS, VI & gw monitoring $99,492
|
in Situ Soil Removal |
|
Why the technology was selected:
In-situ chemical oxidation (ISCO) with sodium permanganate solution was selected for inaccessible contaminated soils above hazardous waste levels due to location beneath building and clay.
Date implemented:
December 2004 (Pilot ISCO under 15 psi at 2 gpm),
April 2005 (Portion of full scale (FS) ISCO under 15 psi at 3 gpm),
June 2005 (Remainder of FS ISCO at 3 gpm - FS interrupted to allow for permanganate to react)
June 2006 (Portion of second FS ISCO wit
Final remediation design:
Excavate accessible soil. Characterize pilot injection area by vertically profiling for VOCs in soil and determining existing levels for arsenic, barium, boron, chromium, lithium and strontium in soil and groundwater. Pilot injection area of 10ft x 10ft x 6ft, with five injection points. Volume of sodium permanganate dependent upon natural oxidant demand, porosity and percent reduction desired. 950 gal injected under pressure during pilot. Soil and groundwater sampling approximately four weeks post-pilot injection. Full scale (FS) injection area of 25ft x 10ft x 10ft, with eight additional injection points (13 total). 2,750 gal injected under pressure during FS. Soil and groundwater sampling approximately twelve weeks post-FS injection to allow for complete reaction with permanganate. Quarterly groundwater monitoring post-FS injection. Second FS injection in same area with three additional injection points (16 total). 110 gal injected passively during second FS injection. Performed 10 quarterly post-inj events and 2 SA events.
Additional remedy necessary. Removal of source area beneath building selected.
Results to date:
Pilot ISCO results one month post injection:
Source area soil reduced from 4900 ppm to 2900 ppm.
Source area groundwater reduced from 110 ppm to 1 ppm.
Full scale ISCO results show rebounding PCE (18,900 - 45,000 ppb) with TCE and cis-1,2-DCE showing up at four orders of magnitude above LOD.
Second full scale ISCO results show unstable PCE ranging between 34,000 and 91,000 ppb between 2006 and 2010. TCE decreases from 9,200 to 215 ppb. Cis-1,2-DCE decreases from 4,600 to < 340 ppb. VC < 100 ppb.
Down-gradient well (adj to sewer lateral) unstable to increasing PCE from 330 to 3,300 ppb, TCE unstable between 860 and 62 ppb, cis decreasing from 130 to 15 ppb, VC < 4 ppb.
Next Steps:
ISCO not successful in obtaining goals of stable to reducing plume and NAPL removal. Removal of source area beneath building necessary. Costs for demolition vs. bracing and replacing structure along with excavation being developed.
Cost to Design and Implement:
Excavation, disposal and monitoring $85,000
Pilot & FS ISCO & monitoring $90,105
2nd FS, VI & gw monitoring $99,492
|
in Situ Chemical Oxidation |
|
Why the technology was selected:
In-situ chemical oxidation (ISCO) with sodium permanganate solution was selected for inaccessible contaminated soils above hazardous waste levels due to location beneath building and clay.
Date implemented:
December 2004 (Pilot ISCO under 15 psi at 2 gpm),
April 2005 (Portion of full scale (FS) ISCO under 15 psi at 3 gpm),
June 2005 (Remainder of FS ISCO at 3 gpm - FS interrupted to allow for permanganate to react)
June 2006 (Portion of second FS ISCO wit
Final remediation design:
Excavate accessible soil. Characterize pilot injection area by vertically profiling for VOCs in soil and determining existing levels for arsenic, barium, boron, chromium, lithium and strontium in soil and groundwater. Pilot injection area of 10ft x 10ft x 6ft, with five injection points. Volume of sodium permanganate dependent upon natural oxidant demand, porosity and percent reduction desired. 950 gal injected under pressure during pilot. Soil and groundwater sampling approximately four weeks post-pilot injection. Full scale (FS) injection area of 25ft x 10ft x 10ft, with eight additional injection points (13 total). 2,750 gal injected under pressure during FS. Soil and groundwater sampling approximately twelve weeks post-FS injection to allow for complete reaction with permanganate. Quarterly groundwater monitoring post-FS injection. Second FS injection in same area with three additional injection points (16 total). 110 gal injected passively during second FS injection. Performed 10 quarterly post-inj events and 2 SA events.
Additional remedy necessary. Removal of source area beneath building selected.
Results to date:
Pilot ISCO results one month post injection:
Source area soil reduced from 4900 ppm to 2900 ppm.
Source area groundwater reduced from 110 ppm to 1 ppm.
Full scale ISCO results show rebounding PCE (18,900 - 45,000 ppb) with TCE and cis-1,2-DCE showing up at four orders of magnitude above LOD.
Second full scale ISCO results show unstable PCE ranging between 34,000 and 91,000 ppb between 2006 and 2010. TCE decreases from 9,200 to 215 ppb. Cis-1,2-DCE decreases from 4,600 to < 340 ppb. VC < 100 ppb.
Down-gradient well (adj to sewer lateral) unstable to increasing PCE from 330 to 3,300 ppb, TCE unstable between 860 and 62 ppb, cis decreasing from 130 to 15 ppb, VC < 4 ppb.
Next Steps:
ISCO not successful in obtaining goals of stable to reducing plume and NAPL removal. Removal of source area beneath building necessary. Costs for demolition vs. bracing and replacing structure along with excavation being developed.
Cost to Design and Implement:
Excavation, disposal and monitoring $85,000
Pilot & FS ISCO & monitoring $90,105
2nd FS, VI & gw monitoring $99,492
|
in Situ Chemical Oxidation |
|
Why the technology was selected:
In-situ chemical oxidation (ISCO) with sodium permanganate solution was selected for inaccessible contaminated soils above hazardous waste levels due to location beneath building and clay.
Date implemented:
December 2004 (Pilot ISCO under 15 psi at 2 gpm),
April 2005 (Portion of full scale (FS) ISCO under 15 psi at 3 gpm),
June 2005 (Remainder of FS ISCO at 3 gpm - FS interrupted to allow for permanganate to react)
June 2006 (Portion of second FS ISCO wit
Final remediation design:
Excavate accessible soil. Characterize pilot injection area by vertically profiling for VOCs in soil and determining existing levels for arsenic, barium, boron, chromium, lithium and strontium in soil and groundwater. Pilot injection area of 10ft x 10ft x 6ft, with five injection points. Volume of sodium permanganate dependent upon natural oxidant demand, porosity and percent reduction desired. 950 gal injected under pressure during pilot. Soil and groundwater sampling approximately four weeks post-pilot injection. Full scale (FS) injection area of 25ft x 10ft x 10ft, with eight additional injection points (13 total). 2,750 gal injected under pressure during FS. Soil and groundwater sampling approximately twelve weeks post-FS injection to allow for complete reaction with permanganate. Quarterly groundwater monitoring post-FS injection. Second FS injection in same area with three additional injection points (16 total). 110 gal injected passively during second FS injection. Performed 10 quarterly post-inj events and 2 SA events.
Additional remedy necessary. Removal of source area beneath building selected.
Results to date:
Pilot ISCO results one month post injection:
Source area soil reduced from 4900 ppm to 2900 ppm.
Source area groundwater reduced from 110 ppm to 1 ppm.
Full scale ISCO results show rebounding PCE (18,900 - 45,000 ppb) with TCE and cis-1,2-DCE showing up at four orders of magnitude above LOD.
Second full scale ISCO results show unstable PCE ranging between 34,000 and 91,000 ppb between 2006 and 2010. TCE decreases from 9,200 to 215 ppb. Cis-1,2-DCE decreases from 4,600 to < 340 ppb. VC < 100 ppb.
Down-gradient well (adj to sewer lateral) unstable to increasing PCE from 330 to 3,300 ppb, TCE unstable between 860 and 62 ppb, cis decreasing from 130 to 15 ppb, VC < 4 ppb.
Next Steps:
ISCO not successful in obtaining goals of stable to reducing plume and NAPL removal. Removal of source area beneath building necessary. Costs for demolition vs. bracing and replacing structure along with excavation being developed.
Cost to Design and Implement:
Excavation, disposal and monitoring $85,000
Pilot & FS ISCO & monitoring $90,105
2nd FS, VI & gw monitoring $99,492
|
in Situ Chemical Oxidation |
|
Why the technology was selected:
In-situ chemical oxidation (ISCO) with sodium permanganate solution was selected for inaccessible contaminated soils above hazardous waste levels due to location beneath building and clay.
Date implemented:
December 2004 (Pilot ISCO under 15 psi at 2 gpm),
April 2005 (Portion of full scale (FS) ISCO under 15 psi at 3 gpm),
June 2005 (Remainder of FS ISCO at 3 gpm - FS interrupted to allow for permanganate to react)
June 2006 (Portion of second FS ISCO wit
Final remediation design:
Excavate accessible soil. Characterize pilot injection area by vertically profiling for VOCs in soil and determining existing levels for arsenic, barium, boron, chromium, lithium and strontium in soil and groundwater. Pilot injection area of 10ft x 10ft x 6ft, with five injection points. Volume of sodium permanganate dependent upon natural oxidant demand, porosity and percent reduction desired. 950 gal injected under pressure during pilot. Soil and groundwater sampling approximately four weeks post-pilot injection. Full scale (FS) injection area of 25ft x 10ft x 10ft, with eight additional injection points (13 total). 2,750 gal injected under pressure during FS. Soil and groundwater sampling approximately twelve weeks post-FS injection to allow for complete reaction with permanganate. Quarterly groundwater monitoring post-FS injection. Second FS injection in same area with three additional injection points (16 total). 110 gal injected passively during second FS injection. Performed 10 quarterly post-inj events and 2 SA events.
Additional remedy necessary. Removal of source area beneath building selected.
Results to date:
Pilot ISCO results one month post injection:
Source area soil reduced from 4900 ppm to 2900 ppm.
Source area groundwater reduced from 110 ppm to 1 ppm.
Full scale ISCO results show rebounding PCE (18,900 - 45,000 ppb) with TCE and cis-1,2-DCE showing up at four orders of magnitude above LOD.
Second full scale ISCO results show unstable PCE ranging between 34,000 and 91,000 ppb between 2006 and 2010. TCE decreases from 9,200 to 215 ppb. Cis-1,2-DCE decreases from 4,600 to < 340 ppb. VC < 100 ppb.
Down-gradient well (adj to sewer lateral) unstable to increasing PCE from 330 to 3,300 ppb, TCE unstable between 860 and 62 ppb, cis decreasing from 130 to 15 ppb, VC < 4 ppb.
Next Steps:
ISCO not successful in obtaining goals of stable to reducing plume and NAPL removal. Removal of source area beneath building necessary. Costs for demolition vs. bracing and replacing structure along with excavation being developed.
Cost to Design and Implement:
Excavation, disposal and monitoring $85,000
Pilot & FS ISCO & monitoring $90,105
2nd FS, VI & gw monitoring $99,492
|
in Situ Chemical Oxidation |
|
Why the technology was selected:
In-situ chemical oxidation (ISCO) with sodium permanganate solution was selected for inaccessible contaminated soils above hazardous waste levels due to location beneath building and clay.
Date implemented:
December 2004 (Pilot ISCO under 15 psi at 2 gpm),
April 2005 (Portion of full scale (FS) ISCO under 15 psi at 3 gpm),
June 2005 (Remainder of FS ISCO at 3 gpm - FS interrupted to allow for permanganate to react)
June 2006 (Portion of second FS ISCO wit
Final remediation design:
Excavate accessible soil. Characterize pilot injection area by vertically profiling for VOCs in soil and determining existing levels for arsenic, barium, boron, chromium, lithium and strontium in soil and groundwater. Pilot injection area of 10ft x 10ft x 6ft, with five injection points. Volume of sodium permanganate dependent upon natural oxidant demand, porosity and percent reduction desired. 950 gal injected under pressure during pilot. Soil and groundwater sampling approximately four weeks post-pilot injection. Full scale (FS) injection area of 25ft x 10ft x 10ft, with eight additional injection points (13 total). 2,750 gal injected under pressure during FS. Soil and groundwater sampling approximately twelve weeks post-FS injection to allow for complete reaction with permanganate. Quarterly groundwater monitoring post-FS injection. Second FS injection in same area with three additional injection points (16 total). 110 gal injected passively during second FS injection. Performed 10 quarterly post-inj events and 2 SA events.
Additional remedy necessary. Removal of source area beneath building selected.
Results to date:
Pilot ISCO results one month post injection:
Source area soil reduced from 4900 ppm to 2900 ppm.
Source area groundwater reduced from 110 ppm to 1 ppm.
Full scale ISCO results show rebounding PCE (18,900 - 45,000 ppb) with TCE and cis-1,2-DCE showing up at four orders of magnitude above LOD.
Second full scale ISCO results show unstable PCE ranging between 34,000 and 91,000 ppb between 2006 and 2010. TCE decreases from 9,200 to 215 ppb. Cis-1,2-DCE decreases from 4,600 to < 340 ppb. VC < 100 ppb.
Down-gradient well (adj to sewer lateral) unstable to increasing PCE from 330 to 3,300 ppb, TCE unstable between 860 and 62 ppb, cis decreasing from 130 to 15 ppb, VC < 4 ppb.
Next Steps:
ISCO not successful in obtaining goals of stable to reducing plume and NAPL removal. Removal of source area beneath building necessary. Costs for demolition vs. bracing and replacing structure along with excavation being developed.
Cost to Design and Implement:
Excavation, disposal and monitoring $85,000
Pilot & FS ISCO & monitoring $90,105
2nd FS, VI & gw monitoring $99,492
|
in Situ Chemical Oxidation |
|
Why the technology was selected:
In-situ chemical oxidation (ISCO) with sodium permanganate solution was selected for inaccessible contaminated soils above hazardous waste levels due to location beneath building and clay.
Date implemented:
December 2004 (Pilot ISCO under 15 psi at 2 gpm),
April 2005 (Portion of full scale (FS) ISCO under 15 psi at 3 gpm),
June 2005 (Remainder of FS ISCO at 3 gpm - FS interrupted to allow for permanganate to react)
June 2006 (Portion of second FS ISCO wit
Final remediation design:
Excavate accessible soil. Characterize pilot injection area by vertically profiling for VOCs in soil and determining existing levels for arsenic, barium, boron, chromium, lithium and strontium in soil and groundwater. Pilot injection area of 10ft x 10ft x 6ft, with five injection points. Volume of sodium permanganate dependent upon natural oxidant demand, porosity and percent reduction desired. 950 gal injected under pressure during pilot. Soil and groundwater sampling approximately four weeks post-pilot injection. Full scale (FS) injection area of 25ft x 10ft x 10ft, with eight additional injection points (13 total). 2,750 gal injected under pressure during FS. Soil and groundwater sampling approximately twelve weeks post-FS injection to allow for complete reaction with permanganate. Quarterly groundwater monitoring post-FS injection. Second FS injection in same area with three additional injection points (16 total). 110 gal injected passively during second FS injection. Performed 10 quarterly post-inj events and 2 SA events.
Additional remedy necessary. Removal of source area beneath building selected.
Results to date:
Pilot ISCO results one month post injection:
Source area soil reduced from 4900 ppm to 2900 ppm.
Source area groundwater reduced from 110 ppm to 1 ppm.
Full scale ISCO results show rebounding PCE (18,900 - 45,000 ppb) with TCE and cis-1,2-DCE showing up at four orders of magnitude above LOD.
Second full scale ISCO results show unstable PCE ranging between 34,000 and 91,000 ppb between 2006 and 2010. TCE decreases from 9,200 to 215 ppb. Cis-1,2-DCE decreases from 4,600 to < 340 ppb. VC < 100 ppb.
Down-gradient well (adj to sewer lateral) unstable to increasing PCE from 330 to 3,300 ppb, TCE unstable between 860 and 62 ppb, cis decreasing from 130 to 15 ppb, VC < 4 ppb.
Next Steps:
ISCO not successful in obtaining goals of stable to reducing plume and NAPL removal. Removal of source area beneath building necessary. Costs for demolition vs. bracing and replacing structure along with excavation being developed.
Cost to Design and Implement:
Excavation, disposal and monitoring $85,000
Pilot & FS ISCO & monitoring $90,105
2nd FS, VI & gw monitoring $99,492
|
in Situ Chemical Oxidation |
|
Why the technology was selected:
In-situ chemical oxidation (ISCO) with sodium permanganate solution was selected for inaccessible contaminated soils above hazardous waste levels due to location beneath building and clay.
Date implemented:
December 2004 (Pilot ISCO under 15 psi at 2 gpm),
April 2005 (Portion of full scale (FS) ISCO under 15 psi at 3 gpm),
June 2005 (Remainder of FS ISCO at 3 gpm - FS interrupted to allow for permanganate to react)
June 2006 (Portion of second FS ISCO wit
Final remediation design:
Excavate accessible soil. Characterize pilot injection area by vertically profiling for VOCs in soil and determining existing levels for arsenic, barium, boron, chromium, lithium and strontium in soil and groundwater. Pilot injection area of 10ft x 10ft x 6ft, with five injection points. Volume of sodium permanganate dependent upon natural oxidant demand, porosity and percent reduction desired. 950 gal injected under pressure during pilot. Soil and groundwater sampling approximately four weeks post-pilot injection. Full scale (FS) injection area of 25ft x 10ft x 10ft, with eight additional injection points (13 total). 2,750 gal injected under pressure during FS. Soil and groundwater sampling approximately twelve weeks post-FS injection to allow for complete reaction with permanganate. Quarterly groundwater monitoring post-FS injection. Second FS injection in same area with three additional injection points (16 total). 110 gal injected passively during second FS injection. Performed 10 quarterly post-inj events and 2 SA events.
Additional remedy necessary. Removal of source area beneath building selected.
Results to date:
Pilot ISCO results one month post injection:
Source area soil reduced from 4900 ppm to 2900 ppm.
Source area groundwater reduced from 110 ppm to 1 ppm.
Full scale ISCO results show rebounding PCE (18,900 - 45,000 ppb) with TCE and cis-1,2-DCE showing up at four orders of magnitude above LOD.
Second full scale ISCO results show unstable PCE ranging between 34,000 and 91,000 ppb between 2006 and 2010. TCE decreases from 9,200 to 215 ppb. Cis-1,2-DCE decreases from 4,600 to < 340 ppb. VC < 100 ppb.
Down-gradient well (adj to sewer lateral) unstable to increasing PCE from 330 to 3,300 ppb, TCE unstable between 860 and 62 ppb, cis decreasing from 130 to 15 ppb, VC < 4 ppb.
Next Steps:
ISCO not successful in obtaining goals of stable to reducing plume and NAPL removal. Removal of source area beneath building necessary. Costs for demolition vs. bracing and replacing structure along with excavation being developed.
Cost to Design and Implement:
Excavation, disposal and monitoring $85,000
Pilot & FS ISCO & monitoring $90,105
2nd FS, VI & gw monitoring $99,492
|
ex Situ Soil Removal |
|
Why the technology was selected:
Excavation was selected for accessible highly contaminated soils due to lack of natural attenuation and clay environment.
Date implemented:
December 2003 (excavation)
Final remediation design:
Excavate accessible soil. Characterize pilot injection area by vertically profiling for VOCs in soil and determining existing levels for arsenic, barium, boron, chromium, lithium and strontium in soil and groundwater. Pilot injection area of 10ft x 10ft x 6ft, with five injection points. Volume of sodium permanganate dependent upon natural oxidant demand, porosity and percent reduction desired. 950 gal injected under pressure during pilot. Soil and groundwater sampling approximately four weeks post-pilot injection. Full scale (FS) injection area of 25ft x 10ft x 10ft, with eight additional injection points (13 total). 2,750 gal injected under pressure during FS. Soil and groundwater sampling approximately twelve weeks post-FS injection to allow for complete reaction with permanganate. Quarterly groundwater monitoring post-FS injection. Second FS injection in same area with three additional injection points (16 total). 110 gal injected passively during second FS injection. Performed 10 quarterly post-inj events and 2 SA events.
Additional remedy necessary. Removal of source area beneath building selected.
Results to date:
Excavated 1,000 tons of accessible soil.
Temporary reduction in groundwater contamination observed post-excavation in two quarterly events at source area. Reduction in groundwater contamination in outlying wells observed in three or four quarterly events. Additional remediation of inaccessible soils necessary.
Next Steps:
ISCO not successful in obtaining goals of stable to reducing plume and NAPL removal. Removal of source area beneath building necessary. Costs for demolition vs. bracing and replacing structure along with excavation being developed.
Cost to Design and Implement:
Excavation, disposal and monitoring $85,000
Pilot & FS ISCO & monitoring $90,105
2nd FS, VI & gw monitoring $99,492
|
Costs
Cost
for Assessment:
|
|
Phase I -- $1,646
Phase II -- $2,900
Site investigation -- $56,412
Cost to date (2014) - $232,553 reimbursed plus $13,700 deductible |
Cost
for Operation and Maintenance:
|
|
Active system not in place. |
Total
Costs for Cleanup:
|
|
|
Lessons Learned
1. Sub-slab sampling of soil and groundwater during initial assessment of site to investigate the start of the sewer line would have provided better understanding of situation prior to excavation. The majority of the source area was not discovered until excavation along the building footings.
2. Extensive documentation of horizontal and vertical soil contamination in source area critical to evaluate effectiveness of ISCO.
3. ISCO originally appeared to be excellent in-situ alternative for this site to address inaccessible clay soils in lieu of building demolition. However, geochemistry of soils and significant NAPL not able to be addressed by ISCO. Building needs to be partially to fully demolished to adequately access source area.
4. A LOT of money has been spent on this site due to owner's insistance structure stays for resale value.
|
Contacts
Jennifer Borski
Wisconsin Department of Natural Resources
625 E. Cty Rd Y, STE 700
Oshkosh, WI 54901-9731
(920) 424-7887
jennifer.borski@wisconsin.gov
Consultant:
Mark Foht
Northern Environmental
954 Circle Drive
Green Bay, WI 53092
(920) 592-8400
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