Transcript Dia 1 - Groundwater Technology

Use of direct
injection techniques
as a sustainable
approach to In Situ
remediation
Solution Provider
for soil & groundwater remediation
Leading in soil and groundwater remediation
> 20 years experience
Solution Provider bij bodemsanering
Groundwater
Technology
Leading in soil and groundwater remediation
Eric de Zeeuw
Content
1. Two cases where direct injection is
the best (only?) option
2. Case 1 in Weesp (ISCR and ISGS)
3. Case 2 in Leiden (ISCR)
4. Case in Leiden: Carbon footprint of
ISCR compared to ISCO and P&T
5. Conclusions
18-7-2015
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Case 1 (Weesp)
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In Situ Chemical Reduction
and
In Situ Stabilisation
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ISCR & ISSTAB
Leading in soil and groundwater remediation
At former Dry Cleaner
Issue
Ex dry-cleaners facility in 16th century
building. Designated monument & on
cultural heritage list; part of old city centre
Weesp on water front
•Volatile chlorinated ethenes, degrading
•Low permeability soil
•Highly susceptible to subsidence
•Transfer of ownership: future liability is an
issue
18-7-2015
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Site Overview
Site
18-7-2015
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Problem
Contamination extends over 150 m2
(source: 60 m2, vertical extent > 7 m);
Migration appears to be minimal;
Typical approach: ‘monitored natural
attenuation’;
Is there an alternative for an infinite
period of monitoring ?
18-7-2015
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Conceptual model
Basic model:
Topsoil, very fine sand, slightly permeable;
0 - 2.5 m
Clay 2.5 – 6 m
Clay & peat layers 6 – 7 m (up to 50 mg/kg
VOCl)
Deeper than 7m: Aquifer (7 – 10 m: fine
sand)
18-7-2015
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GT Solution
Ruled out:
Pump & treat, sparge & vent (subsidence)
ISCO (presence of peat)
Excavation
Ruled in:
In Situ chemical reduction
In Situ stabilization
18-7-2015
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ISSTAB
ISGStm = a catalyzed, buffered sodium
permanganate (delivered by Adventus
USA):
In the presence of an organic compound
(R), MnO4- reactions yield an oxidized
intermediate (Rox) or CO2 ,… plus MnO2
R + MnO4-  MnO2 + CO2 or Rox
18-7-2015
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GT approach
Intensive mass reduction followed by in situ
stabilization
Intensive step:
In Situ Chemical Reduction: inject microiron slurry (ZVI)
Inject substrate & nutrients to promote in
situ biodegradation along the harbour side
Polishing step:
Reduce permeability to stop migration
18-7-2015
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Implementation
Two injection zones:
1. In front of premises
 First round: 20 injection points, some oblique
underneath building, to 7 m – grade: nanoiron & substrate
 Second round: 20 injection points, some
oblique underneath building, to 7 m – grade:
to reduce permeability
2. Near the waterfront
 15 injection points (vertical) as precaution
18-7-2015
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Costs / duration
18-7-2015
Option
Duration
Cost estimate (euro)
monitoring
perpetual
€1500 per annum
Basic injection (nanoiron)
Per injection event: 1
week;
Total: 1-2 years
€35K
Additional injection
(substrate)
No additional time;
May save one basic
injection round
€17K
In Situ Fixation
No additional time;
May save one basic
injection round
€16K
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Case 2 (Leiden)
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Leading in soil and groundwater remediation
Former dry cleaner: Soil
contaminated
by
Solution
Provider bij bodemsanering
Chlorinated
Leading in soil
and groundwater remediation
Hydrocarbons
ISSUE
 Remediation (soil & groundwater) in
early ’90-s failed.
 Dewatering for roadworks will
spread contamination in source
zone (& in plume)
 GT requested to ‘keep source in
place’
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SITE OVERVIEW
Site
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Conceptual model
Topsoil, fine sand, slightly permeable; 0 1.5 m
Clay and peat 1.5 – 4.5 m
Deeper than 4.5 m: fine sand with clay
layers (around 7 m DNAPL)
Source 150 m3: Concentrations PER up to
2,300 mg/kg (6.5 – 7.0 m) 560 kg PER
Plume: 16,500 m3  33 kg PER, 29 kg TRI,
7 kg CIS and 5 kg VC
18-7-2015
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SOURCE ZONE 150 m2
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OVERVIEW PLUME
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SOLUTION
Options evaluated:
 ISCO (Peroxide&Ozone) (Not in
peat layers) as option to address
source zone
 In Situ chemical reduction as
containment measure between the
source zone and the dewatering
 Biological approaches are not
applicable in view of the relatively
short timeframe.
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TIME & COSTS
Option
Duration
Cost estimate (euro)
Peroxide & ozone
22 weeks;
€66.000
Zero valent Iron injection
2 weeks
€36.000
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for soil & groundwater remediation
Carbon Footprint Method
SKB-project Carbon Footprint Soil
Remediation
Project management TAUW
Members: Groundwater Technology (and
others)
Result: Spreadsheet Model Calculation
CO2 emissions
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Result: CO2 3 Years P&T
Groundwater extraction
Groundwater purification
0.1
0.8
1.7
36.8
System construction
Purification part
Extraction
4.4
Substances / chemicals
1.0
Waste products
Transport
120.9
• Water treatment 159.5 Tons,
extraction 6.2 Tons CO2
Transport
Result: ISCO (O3/H2O2)
ISCO: 5.7 Tons CO2
Result: ISVR (ZVI)
ZVI: 4.2 Tons CO2
CONCLUSIONS
A SUSTAINABLE APPROACH?
• LESS CO2-EMISSIONS
• LESS €
• LESS DAMAGE (eg. Subsidence)
• NO HINDRANCE
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Thanks for your
Attention
Groundwater Technology BV
Sheffieldstraat 13 P.O. Box 12115
Solution
bodemsanering
3047 ANProvider
Rotterdambij3004
CG Rotterdam
Solution Provider
for soil & groundwater remediation
Leading in soil and groundwater remediation
Tel: +31 (0)10
238 2850
Leading in soil and groundwater
remediation
Incident response: +31 (0)10 238 2868
Fax: +31 (0)10 238 2869
E-mail: [email protected]
Web: www.gtbv.nl