Session B Remediation of Soil and Groundwaternordrocs.org/.../Session-B-Remediation-of-Soil-and... · Remediation – of Soil and Groundwater Part I Chair: Marja Tuomela Ph.D., Co-op

Session B

Remediation – of Soil

and Groundwater

Part I

Chair: Marja Tuomela

Ph.D., Co-op Bionautical and University of Helsinki, Finland

Environmental forensics. Searching for a major unknown PCE source

in an industrial area using different tools, Birkerød, Denmark

Thomas Hauerberg Larsen

M.Sc., Ph.D., Orbicon, Denmark

Development of an iron-based soil mixing remediation method

for energyefficient treatment of chlorinated solvents

Per Lindh

Ph.D., Swedish Geotechnical Institut, Sweden

Da Nang – an outstanding thermal remedy 5 years later

Niels Ploug

Sales and Product Manager, Krüger, Denmark

Danang

An out standing thermal remedy

five years later

Nordrocs 2018

Use of Agent Orange in Danang

Krüger Soil Remediation

• Operation Ranch Hand – herbicides for

defoliation

• Agent Orange contained dioxin as

2,3,7,8-TCDD

• Over 100,000 barrels used in Danang

• USAID lead agency for cleanup

Danang Airbase - 1972

Impacted areas


o Environmental assessment – 151 samples

o Excavation areas

o ~20 Ha total area

o 15 cm til > 3 m depth

o 80.000 – 90.000 m3

Choice of technology


Efficiency Only known alternativ to reach Vietnamese dioxin standards (1,000 ppt)/(150 ppt)

Environmental impact IPTD scores lowest impact in EA

Economy IPTD costs in same range as other alternatives when long term landfill O&M was considered

Why IPTD?


Design


Design


Pile

Structure

Grade Level

Insulated

Sidewall Panel

Steel Sheeting

Drain Piped

to Sump

Drainage

Layer

Insulated

Floor

Insulated Surface

Cover

Air Inlet Well Heater-Only

Well

Horizontal Vapor

Extraction Well

• 105 m x 70 m x 6 m pile

• Volume = 43.750 m3

• 1,254 heater wells

• Horizontal extraction

• Air inlet

• 56 temperature-monitering wells

• Treatment of gas & fluid by cooling,

phase separation, filtering and adsorption


Phase 1 - operation


Phase 1: October 2014 continuous rain


Temperature avg.

by treatment zone

depth

Phase 1 – Soil temperatures


Confirmatory sampling


• Verify concentrations < 150 ppt

• Pile divide into 1 m decision units

• Triplicate collected for one layer

-1 m

-0 m

-2 m

-3 m

-4 m

DU-1

DU-2

DU-3

DU-4

Phase 1 Final Sample Reults May 2015


Cooling and Removing Treated Material


o Phase 1 pile quenched May-July 2015

o Treated soil removed Sep/Oct 2015

Design modifications for Phase 2


Phase 2 – Design Modifications


Design

o Heater elements

o Cover

o Liquid Treatment Plant

o Mass balance

o Collect initial samples in pile

o Increase sampling on Liquid

Treatment Plant

Modified Heater Design


Bottom 2m boost

Re design vapor cover


210 kg/cm2

210 kg/cm2

Phase 2 - Operation


Phase 2 – Pre-tretament concentrations


Phase 2 – Soil temperatures


50100150200250300350400450500550600650700750800850900950100010501100

104070

100130160190220250280310340370400430460490520550580610

10/07/16 11/26/16 01/15/17 03/06/17 04/25/17 06/14/17 08/03/17

Tem

pe

ratu

re [º

F]

Tem

pe

ratu

re [º

C]

Date

50 cm 150 cm 250cm 350 cm 450 cm 550 cm 600 cm

Start heatin

g

Qu

ench

start

10

0ºC

Heaters o

ff &start

of

con

firmatio

nsam

plin

gTemperature avg.

by treatment zone

depth

Phase 2 – Final Sample Results (June 2017)


IPTD met stringent cleanup standard with > 99,99%

Robust design necessary

Pre design to complete

cleanup in less than 9 years

Danang Airport ready for

transfer in 2018

Conclusions


Project team


1

Development of an iron-based soil mixing

remediation method for energy

efficient treatment of chlorinated solvents

Per Lindh, PhD

2

Clarification

In geotechnical engineering stabilization with a binder is to blend

a soil with a binder to enhance the geotechnical performance

of the soil.

In remediation this technique is called solidification.

3

Background

A former remediation project with TCE contaminated soil

run by Region Hovedstaden has shown good results

regarding degradation of the pollution. However, it resulted in

low strength and bearing capacity of the treated soil.

This problem was caused by the method used,

blending a slurry mix of bentonite and ZVI in the soil.

4

Goal

Our goal is to find an energy efficient, robust soil mixing

method to reduce the pollutant and stabilize/solidify any

remaining pollution.

The treatment should also give a stable ground for future

development of the treated area.

5

Spiked soil or in situ polluted soil?

During the first discussion regarding spiked or in situ polluted

soil we chose spiked soil due to;

• Less spread in pollution level – better control

• We could design the experiment in a better way

• Less handling of pollutants in the lab

6

Challenges

This project involves new testing methods that need to

be developed including handling of the specimens due

to the volatile compounds. How do we produce a specimen

were we are sure to measure degradation not evaporation?

Optimizing testing program with respect to quality,

reproducibility and budget

Choosing a good iron oxide source together with different

binders – iron sulfate adversely affect strength development.

Finding a strength increase that is both practical and slow

enough to let the iron oxide decompose the pollution.

7

Nondestructive testing - method

8

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 5 10 15 20 25 30 35 40 45 50

P-w

ave

ve

loci

ty (

m/s

)

Curing time (days)

1_5050_55_0_1

1_5050_55_0_2

1_5050_0_6000_1

1_5050_0_6000_2

2_5050_XX_0_1

2_5050_XX_0_2

3_5050_XX_0_1

3_5050_XX_0_2

5%_5050_0_0_2

5%_5050_0_0_5

Nondestructive testing - results

9

Specimen one, blend one for strength testing

Specimen two, blend one for degradation testing (day x)

Recipe one blend one

Blending mould

Specimen three, blend one for degradation testing (day x + 30)

Specimen four, blend one for degradation testing (day x + 90)

Specimen one, blend two for strength testing

Specimen two, blend two for degradation testing (day x)

Recipe one blend two

Blending mould

Specimen three, blend two for degradation testing (day x + 30)

Specimen four, blend two for degradation testing (day x + 90)

How do we reduce laboratory work and keep quality

10

Specimen one, blend one for strength testing

Specimen two, blend one for degradation testing (day x)

Recipe one blend one

Blending mould

Specimen three, blend one for degradation testing (day x + 30)

Specimen four, blend one for degradation testing (day x + 90)

Specimen one, blend two for strength testing

Specimen two, blend two for degradation testing (day x)

Recipe one blend two

Blending mould

Specimen three, blend two for degradation testing (day x + 30)

Specimen four, blend two for degradation testing (day x + 90)

How do we reduce laboratory work and keep quality

If necessary additional specimens

11

Mixing parameters

Binder component one

0.0 0.2 0.4 0.6 0.8 1.0

Bin

de

r co

mp

on

en

t tw

o

0.0

0.2

0.4

0.6

0.8

1.0

Y = 1 - X

0.0

0.2

0.4

0.6

0.8

1.0

0.00.2

0.40.6

0.8

1.0

0.20.4

0.60.8

1.0

Z =

Bin

der

com

ponent th

ree

X = Binder component oneY = Binder component two

(1,0,0)

(0,0,1)

(0,1,0)

Z =

1 - X

X =

1 - Z

Y = 1 - X

x+y+z=1

12

Bin

der

conte

nt

TC

E le

vel

Fe(II) content

23-Factor design

33-Factor design

Low

Low

Low

Medium

Medium

Medium

High

High

High

Process parameters

13

Bin

der

conte

nt

TC

E le

vel

Fe(II) content

33-Faktorförsök

FC CCD

Low

Medium

High

Low

LowMedium

Medium

High

High

Process parameters

14

Bin

der

conte

nt

TC

E le

vel

Fe(II) content

33-Faktorförsök

Box-Behnken design

Low

Medium

High

Low

LowMedium

Medium

High

High

Process parameters

15

Different goals – How to choose?

• Degradation

• Strength

• Resistance

• Economy

• Environmental aspects

16

Simplex lattice

How to choose the optimum blend?

S lag0 10 20 30 40 50 60 70 80 90 100

P ersu lfa te

0

10

20

30

40

50

60

70

80

90

100

C em ent

0

10

20

30

40

50

60

70

80

90

100

> 3 5 0 0

< 3 5 0 0

< 3 0 0 0

< 2 5 0 0

< 2 0 0 0

< 1 5 0 0

< 1 0 0 0

< 5 0 0

< 0

Fi tte d S u rfa ce ; V a ri a b l e : UCS

DV : UCS ; R-sq r= .9 9 0 9 ; A d j :.9 8 8 5

M o d e l : Q u a d ra ti c (so m e te rm s we re re m o ve d fro m fu l l m o d e l )

Example from PAH contaminated sediment

17

How to choose the optimum level?

18

Shear strength as a function of P-wave velocity

P-wave velocity (m/s)

200 400 600 800

Sh

ea

r str

en

gth

(kP

a)

0

100

200

300

400

500

600

in situ sampled specimens tested in labregression from in situ sampleHW LB 14 day specimens from this study

pl-2017

Can we use same parameters in lab and in situ?

19

I would like to thank you for your attention and also thank

my colleagues in this project

Katerina Hantzi, Region Hovedstaden

Anna Toft, Region Hovedstaden

Annika Fjordbøgge, DTU

Cecilia Toomväli, SGI

Annika Åberg, former at SGI (Sweco)

Erik Bergstedt, SGU

Wilhelm Rankka, SGI

Torben Højbjerg Jørgensen, COWI

Fredrik Burman, SGI

Christopher Robb, Geosyntec

Control group

Helen Kennedy, SGI

Klas Arnerdal, SGU

Carsten Bagge Jensen, Region Hovedstaden

Contact information: [email protected]

Once upon a time…or the mystery of the

hidden PCE source Thomas Hauerberg Larsen, Orbicon

Ida Damgaard, Capital Region of Denmark

(CRD)

Anna Toft, CRD

Katerina Hantzi, CRD

Arne Rokkjær, CRD

Flemming Vormbak, CRD

Kresten Andersen, Orbicon

Simon Hansen, Orbicon

Outline

• Once upon a time….

• The set-out – triggering of the quest for a PCE source

• Finding the source (or almost we believe…..)

– Analysis of the remedial stream

– Model with particle tracking

– Comparing known source with remedial stream (CSIA)

– A new set of wells, and another new set of wells….

• Whats next?

• Wrap up

Once upon a time in 1961 (my year of

birth) and now

Primary developement of Birkerød Industrial Area (BIA) took place in the 1960’ies – some newer buildings too. Total area around 50 ha.

Activities/sources in the area

Small – medium sized companies

12. september

2018

4

Chrome plating

TCE storage and handling for degreasing metal & electronics

Broken sewers

Production of glues, detergents etc.

Repair shops & garages

Known & probable polluted sites in BIA

TCE

TCE TCE

TCE

TCE

PCE Cr6

TCE

Red hatch: Known pollution (V2 register) Blue hatch: Suspected pollution (V1 register) Yellow arrow: Overall groundwater flow direction appr 10 m/y Bold characters are known major sources

TCE

General conceptual model chlorinated

spills in BIA

12. september

2018

6

Sandy clay-till

Meltwater sand

Unsaturated sand

Remedies

12. september

2018

7

TCE Thermal & SVE

TCE TCE SVE

TCE

TCE

PCE Cr6

TCE

Capital Region of Denmark (CRD) • Investigate, • Risk assess • Prioritize • Remediate

Two sites are undergoing remedy at the moment: • Klintehøj Vænge 16, soil vapor

extraction (SVE), ongoing • Pilehøj Vænge 10, Thermal

and SVE, ongoing • Hammerbakken 10 are in the

making and will be started shortly

The contaminated sites in the northern part of BIA poses a threat to 2 major drinking water supplies

TCE Thermal

SVE on Klintehøj Vænge 16

• 4 wells in the unsaturated sand

• Air exchange rate 40 m³/h well

• Based on a pumping test where

pneumatic conductivity of the

sand as well as the leakage of

the sandy clay-till was

determined

• Design parameter where a total

air exchange rate of appr. 1000

PV/year below Klintehøj Vænge

16

12. september

2018

8

V2

V1

V3

V4

SVE on Klintehøj Vænge 16 - 1

12. september

2018

9 TCE removal rate in average appr. 13 kg/y

SVE on Klintehøj Vænge 16 - 2

12. september

2018

10 PCE removal in average 24 kg/y, 8,5 kg TCE/y now

PCE Concentration (µg/m³) in the wells Sept.

2017

12. september

2018

11

12000

76000 6

16

Known & probable polluted sites in BIA

TCE

TCE TCE

TCE

TCE

PCE Cr6

TCE

Red hatch: Known pollution (V2 register) Blue hatch: Suspected pollution (V1 register) Yellow arrow: Overall groundwater flow direction appr 10 m/y Bold characters are known major sources

Blokken 25

TCE

Modelling

• The two SVE plants ran at

different times with different flow

• Particle tracking analysis done

with variations in the

hydraulic/pneumatic parameters

(radial, homogenous scenarios,

transient in time)

• Conclusions

– Theoretical possible that

particles from Blokken 25 could

arrive at Klintehøj Vænge 16

after 2 years

– Suspicious that the observed

amount originate from Blokken

25 12. september

2018

13

Modelled pressure distribution (Pa) and particle tracking trajectories

CSIA sampling and analysis

• Compound Specific Isotope

Analysis (CSIA) can be used to

distinguish between sources

• Different isotope pairs can be

used, typically 13C/12C, 37C/35Cl, 2H/1H, 18O/16O, 15N/14N

• Measured by GC-MS with special

equipment (commercially

available for some isotopes)

12. september

2018

14

Composition statistically different. Klintehøj Vænge 16 less degraded

A new set of wells and sampling

12. september

2018

15

PCE in soil gas (µg/m³) in deep sand

PCE in top groundwater (µg/l) in deep sand

Area under suspicion

Back in the archives once more

• New historical reviews done on

the properties located within the

blue ring

– Minor use of solvents –

probably most TCE

– No known/suspected PCE

source based on the reviews

• The none hatched properties

within the ring has probably not

used solvents, based on a

screening done before the

reviews

• Investigation ongoing – reports

in the making

12. september

2018

16

Its warming up…….

12. september

2018

17

PCE in soil gas (µg/m³) in deep sand

PCE in top groundwater (µg/l) in deep sand

Area under suspicion

Whats next…..

12. september

2018

18

• Maybe the pollution detection dog

• Thorough soil gas investigation near surface in area of interest

• Possibly followed by drilling to get soil samples for a mass estimate

• Decision making – is running the SVE enough or….

Inside the halls

Wrap up

• Old industrial area with lots of

sources

• Already screened for major

sources early on

• PCE suddenly turns up in SVE

designed for a TCE site

• One known PCE source in area –

unlikely to be the origin based on

direction flow, intuition and

general knowledge of SVE

operation

• Modelling shows a theoretical

impact, mass flux probably

unrealistic

• CSIA shows different origin of

PCE in extracted air and the

known source

• Two round of new wells and

sampling of deep soil gas and

water narrows down area of

interest

• Area needs to be pin-pointed

more (now appr. 2500 m²)

before a mass estimate can be

made

• Decision making about the

future of the SVE operation

12. september

2018

19

Documents

Session B Remediation of Soil and Groundwaternordrocs.org/.../Session-B-Remediation-of-Soil-and... · Remediation – of Soil and Groundwater Part I Chair: Marja Tuomela Ph.D., Co-op