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Leading in soil and groundwater remediationSolution Provider for soil & groundwater remediation

Leading in soil and groundwater remediation

Use of direct injection techniques

as a sustainable approach to In Situ

remediation> 20 years experience

Groundwater TechnologyEric de Zeeuw

Solution Provider for soil & groundwater remediation

Content

19-04-23

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

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Leading in soil and groundwater remediationSolution Provider for soil & groundwater remediation

Leading in soil and groundwater remediation

Case 1 (Weesp)

In Situ Chemical Reduction and

In Situ StabilisationISCR & ISSTAB

At former Dry Cleaner

Solution Provider for soil & groundwater remediation

Issue

19-04-23

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

Solution Provider for soil & groundwater remediation

Site Overview

19-04-23

Site

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Problem

19-04-23

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 ?

Solution Provider for soil & groundwater remediation

Conceptual model

19-04-23

Basic model:Topsoil, very fine sand, slightly permeable; 0 - 2.5 mClay 2.5 – 6 mClay & peat layers 6 – 7 m (up to 50 mg/kg VOCl)Deeper than 7m: Aquifer (7 – 10 m: fine sand)

Solution Provider for soil & groundwater remediation

GT Solution

19-04-23

Ruled out:Pump & treat, sparge & vent (subsidence)ISCO (presence of peat)Excavation

Ruled in:In Situ chemical reductionIn Situ stabilization

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ISSTAB

19-04-23

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

Solution Provider for soil & groundwater remediation

GT approach

19-04-23

Intensive mass reduction followed by in situ stabilizationIntensive step:In Situ Chemical Reduction: inject micro-iron slurry (ZVI)Inject substrate & nutrients to promote in situ biodegradation along the harbour sidePolishing step:Reduce permeability to stop migration

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Implementation

19-04-23

Two injection zones: 1. In front of premises

First round: 20 injection points, some oblique underneath building, to 7 m – grade: nano-iron & 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

Solution Provider for soil & groundwater remediation

Costs / duration

19-04-23

Option Duration Cost estimate (euro)

monitoring perpetual €1500 per annum

Basic injection (nano-iron)

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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Leading in soil and groundwater remediationSolution Provider for soil & groundwater remediation

Leading in soil and groundwater remediation

Case 2 (Leiden)

Former dry cleaner: Soil contaminated by

Chlorinated Hydrocarbons

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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

19-04-23

Topsoil, fine sand, slightly permeable; 0 - 1.5 mClay and peat 1.5 – 4.5 mDeeper 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 PERPlume: 16,500 m3 33 kg PER, 29 kg TRI, 7 kg CIS and 5 kg VC

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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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Carbon Footprint Method

SKB-project Carbon Footprint Soil Remediation

Project management TAUWMembers: Groundwater Technology

(and others)Result: Spreadsheet Model Calculation

CO2 emissions

Result: CO2 3 Years P&T

• Water treatment 159.5 Tons, extraction 6.2 Tons CO2

Result: ISCO (O3/H2O2)

ISCO: 5.7 Tons CO2

Result: ISVR (ZVI)

ZVI: 4.2 Tons CO2

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CONCLUSIONS

A SUSTAINABLE APPROACH?• LESS CO2-EMISSIONS

• LESS € • LESS DAMAGE (eg. Subsidence)• NO HINDRANCE

Solution Provider bij bodemsanering

Leading in soil and groundwater remediationSolution Provider for soil & groundwater remediation

Leading in soil and groundwater remediation

Groundwater Technology BV

Sheffieldstraat 13 P.O. Box 121153047 AN Rotterdam 3004 CG Rotterdam

Tel: +31 (0)10 238 2850Incident response: +31 (0)10 238 2868

Fax: +31 (0)10 238 2869

E-mail: info@gtbv.nl Web: www.gtbv.nl

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