Case1

Engineering Company： Obayashi Corporationz Engineering company :Obayashi corporation one of the largest general contractor in Japanz Site Location: Nagoya, Japanz Site Area : 6,780.8m2Treatment Area : 6,780.8m2 Depth : 12mz Hydrogeology in brief :Upper sandy and lower silty sand unit was separated by discontinuous silty-claylens. Hydraulic conductivity varied between 10-3 to 10-4 cm/sec. From initialstage the groundwater was anaerobic because of high natural TOC.
z Contamination signature :Groundwater ・TCE (up to 40 times of Japanese environmental standard 0.03mg/L)・cis-DCE(up to 190 times of Japanese environmental standard 0.04mg /L)
Soil
・TCE (up to 19 times of Japanese environmental standard 0.03mg/L)・cis-DCE (up to 14 times of Japanese environmental standard 0.04mg /L)z Treatment : Pump and treat was done for several months. As a result thecontamination concentration was reduced.
・TCE(up to 10 times of the environmental standard 0.03mg/L)・ cis-DCE(up to 100 times of the environmental standard 0.04mg /L) )z This is followed by injection of EDC.

Case 1 Engineering Company： Obayashi CorporationORP contour map showing change after injection

Prior to EDC injection

Inception of EDC injection

1 week after the start of injection

Completion of the injection

Case 1 Engineering Company： Obayashi Corporation

TCE concentration change

Prior to EDC injection

Post EDC injection

TCE
concentration

2 months after the injection

2.5 months after the injection

Case 1 Engineering Company： Obayashi Corporation

cis-DCE concentration change

Prior to EDC injection

Post EDC injection

cis-DCEconcentration

2 months after the injection

2.5 months after the injection

Case2Engineering Company：
MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.
•Site location: Kanto region, Japan•Site characteristics: The site has sandy-silt and silty units with hydraulicconductivity less than 10-4cm/sec. The contaminated depth was up to 1015 m from GL with the concentration of TCE and cis-DCE varying from lessthan 1 mg/L to more than few hundred mg/L in the groundwater.
•Treatment: Bioremediation was directly applied without heat treatment atthe locations with contamination concentration approximately 100mg/L orbelow.
Concentration(mg/L)

cis-DCEEthylene
VCDAYS (up to injection of EDC)

Case 2 Engineering Company： MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.

• At the locations with more than 100 mg/L ofcontamination concentration ｔhe remediation was donein two phases. the subsurface was heated at up to80oC and soil gas and groundwater was extracted undervacuum.
•Once the concentration fell below 100mg/L EDC wasinjected. Groundwater from the surrounding area wasused as the microbial seed while diluting EDC.

Case 2 Engineering Company： MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.

Two Phase treatment

Concentration

Method＞

100mg/ℓ〜 10mg/ℓ＞

Subsurface heating and Gas/liquid
phase vaccum extraction

EDC based bioremediation

Case 2 Engineering Company： MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.

DNAPL containing zone was heated followed by vaccum extraction of soil
gas and groundwater.

Results

Application of heat resulted in incresed permeability offormation. Gas extraction volume increased from 2060L/day (before heating to 100-400L/day after heating).

Hearting points

Monitoring well

Monitoring well
FillerSilty- sandHeating zone
Sandy-silt
Hydraulicconductivity

Temp.(40-60℃)/
Electric heaterCase 2 Engineering Company： MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.

Results of phase 1 & 2 treatments
Concentration by the environmental standard ● Monitoring well

TCE concentration● Heating points

×1 ×10 ×100 ×10000m

c-DCE concentration

Initial stage◆ EDC injection well

Post Heat-treatment

5m

10m 15m

Post EDC based
bioremediation

Case 2 Engineering Company： MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.

Post Heat-treatment EDC based bioremediation

TCE (Japanese environmental standard 0.03mg/L)

1000

cis-DCE (Japanese environmental standard 0.03mg/L)

Concentration (mg/L)

1001010.1

0.01

0.001

1Inception of EDC based
bioremediation

5(month)

10Case3Engineering Company： KOA KAIHATSU CO., LTD

Locations

Ground water contamination plume

Soil Gas Survey Results

Target treatment Area with contamination
exceeding environmental standard

Case 3 Engineering Company： KOA KAIHATSU CO., LTD

Hydrogeological modeling for EDC injection design

Case 3 Engineering Company： KOA KAIHATSU CO., LTD

PCE concentration change
250000250000200000200000

0.45

2.5

0.4

20.35
1.5

150000150000

0.3

10.25
0.2

0.5

1000000.4

0.15

100000

0.1
0.3

0.05
0.250000

0.1

0.04

50000

0.03
0.02

0.01

050m

0.01

0.001

050m
0.001

50000

10000015000020000025000030000035000040000050000

2500002000000.02

1500000.015

100000

0.01

50000

0

10000015000020000025000003-Oct-2005

30000050m

35000015000020000025000017-Dec-2004

30-Jan-2004 (Prior to injection)

50000

1000004000000.001

300000350000400000Case 3 Engineering Company： KOA KAIHATSU CO., LTD

cis-DCE concentration change
250000250000200000200000
0.28

0.12
0.24

150000150000
0.1

0.2

0.16

1000000.08

100000

0.12

0.06
0.08

50000

50000
0.04

0.04

05000010000015000020000025000030000050m

350000

00.01

50m
0.004

400000

50000

10000030-Jan-2004 (Prior to injection)

15000020000025000030000035000040000017-Dec-2004
2500002500002000002000000.12
0.11500001500000.06

100000

0.05

50000

0.04

0.09
0.08

100000

0.07
0.06
0.05

50000

0.04

0

50000

10000015000020000025000003-Oct-2005

30000050m

350000400000

050m

0.004

0.004

50000

10000015000020000025000031-Jan-2006

300000350000400000