DNAPL (DDT, CB) Remediation
200 year-old Manufacturing Site in Pennsylvania
ENVIRONMENTAL
REMEDIATION
SERVICES &
PRODUCTS
SITE HISTORY
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Over 200 years of on-site chemical manufacturing
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Multi-component DNAPL present at fill-native clay interface
Chlorinated Contaminants & Mass
Concentrations as % of Total COCs
INITIAL BENCH STUDY
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Cool-Ox® Selected:
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Both Cool-Ox® and heat activated sodium persulfate achieved >80% COC destruction
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Cool-Ox® was selected as the oxidizing and reducing agent because no activation was required.
SUPPLEMENTARY BENCH SCALE TEST
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Selectivity of ISCO/ISCR treatment? Or
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Distribution of alkanes in fine-grain matrix?
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What about dose-response?
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Optimum pH 8-9.5
DOSE RESPONSE
WORKING SAFELY
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9,020 safe work hours under adverse weather conditions (snow/sleet) and subzero temperatures
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Incident-free completion
“Outstanding achievement! An unannounced internal audit with nothing but positive findings!
This is a true demonstration of your strong EH&S culture and leadership.
Thank you all for living and working safely!”
- EH&S Remediation Manager - Global Remediation Business
PILOT DEMONSTRATION RESULTS
Relative Mass Relationships Before & After Pilot
Primary COCs Before Reduced by
Chlorobenzenes: 51% 73%
Total DDX: 34% 86%
1,2-Dichloropropane: 8% 72%
FULL-SCALE TREATMENT
As designed:
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1,766 injection points on 6’x6’ grid
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First dosing rate selected based on chemical costs and field mobilization costs
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First dosing aimed at 80% COC mass removal at locations with 7,500 mg/kg COC or less
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Field results indicated reagent dosage rates limited by subsurface acceptance
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10 subareas found to require second treatment
As Implemented:
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2,072 injection points (primary, secondary combined)
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154,260 gallons of Cool-Ox® injected
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10,284 injected linear feet
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Reduced COC mass by 67% (311,000 pounds)
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Overcome acid soil conditions
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Proved “Big-Sites” can be treated with ISCO/ISCR
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Pre-planned injection sequence avoided need to remobilize injection rig
Cool-Ox® Foaming Reaction
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Primary injection reduced subsurface COC mass by 64%
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Secondary Injections destroyed over 311,000 lbs. of DDT, DDX, CB, BCEE (reduced COC mass by 67%) in 4.5 months - URS data
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The total DNAPL mass destroyed was over 305,000 lbs.
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3 grams COC removal per gram Cool-Ox® (slightly better than predicted by bench study!)