Soil and Groundwater Contamination Survey and Countermeasure Technologies

Category of Tchnology	Treatment	In Situ Decomposition Technology
Media	Groundwater, Soil Gas
Contaminants	Volatile Chlorinated Organic Compounds (TCE, PCE, etc)
	Applied (Demonstrated) Substances	Volatile Chlorinated Organic Compounds
Scope	Concentration Range
	Hydrogeological Conditions	Saturated Unsaturated	Permeable Layer
	Chemical Soil Properties
	Other Remarks
Technology Description	Classification
	Status	Fully Commercialized
	Outline of Technology	Steel pipes with a small diameter and strainer are driven into the soil.  Soil gas and contaminated groundwater are simultaneously extracted by negative high pressure.  The water in the soil vapor is then separated by an air/water separator installed on the ground.
	Required Pre- and Post-treatment	Air/water separation and discharged water and gas treatment are necessary.
	Enhance Effectiveness through Combination
	Case History	The maximum concentration of surface soil vapor was reduced from 519 ppm to 32 ppm.  1,095 kg of trichloroethylene was collected in 10 months, 84% of which were from the extracted soil vapor.
	Application Examples	Precedent in Osaka Pref.
	Limitations	Remediation is capable down to approx. 7 m in depth.
	Properties of Treated Soil	-
Schematic Flow Process
Applicability	In Situ Applicability	Possible
	Ground Structures	Not Applicable
	Required Excavation	Installation of steel pipe of 50cm diameter.
	Groundwater Extraction
	Required Space
	Operational Time	A few months - 1 to 2 years
	Installation Time
	Maintenance and Control Requirements
	Additional Remarks
Secondary Impacts to Environment	Secondary Treatment Required?	Effluent Water Treatment    Off-gas Treatment
	Effects on Living Environment	Noise
	Additives
	Possibility of Contaminant Spreading	None
	Secondary By-products	None

• Understanding the Contamination Survey and Countermeasure Technology Description Sheet
• Where to make contact

Soil Environment Management Division, Water Environment Department, Environmental Management Bureau, Ministry of Environment
Tel: +81-3-5521-8319
E-mail: MOE@env.go.jp