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| Resource Library > Technology Transfer > Programs and Initiatives > Source Zone Treatment > Background > Cost |
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Source Zones - Cost
While any of several different approaches may be applied to control, reduce, or remove a particular LNAPL or DNAPL source zone, the success in addressing the NAPL source, and the associated costs, depend to a large degree on site-specific and contaminant-specific factors, including:
- Nature of the subsurface medium (e.g., fractured bedrock, clay, sand, etc.)
- Geologic, hydrologic, and geochemical heterogeneity of the subsurface
- Degree of saturation
- Depth to water table
- NAPL-specific physical and chemical properties
Details regarding these factors are presented in this linked Table.
Prior to selecting an approach for addressing a NAPL source zone, the site and the nature and extent of the NAPL source zone must be adequately characterized, and the factors listed above must be considered carefully. Nevertheless, some generalizations can be made regarding the likely degree of suitability and relative cost of several currently-available technologies for addressing LNAPL and DNAPL source zones. Treatment technologies, degree of suitability for particular contaminated media, and relative costs associated with their application, are presented in the LNAPL and DNAPL Source Zone Tables below. Note that possible treatment technologies for LNAPL source zones and DNAPL source zones are presented separately, because the physical and chemical characteristics of common LNAPL and DNAPL contaminants can lead to quite different behaviors, and corresponding responses to treatment, in the subsurface environment.
Because the cost and performance of NAPL source-zone treatment approaches are highly dependent upon site-specific and contaminant-specific factors, site managers and remediation professionals are strongly encouraged to utilize available case histories (FRTR Multi-Site Assessment Reports, FRTR Remediation Case Studies Searchable Database, TechKNOW, USACE Cleanup Technologies) existing screening tools (FRTR Remediation Technologies Screening Matrix, GWRTAC) or computer-based Decision Support Systems (DSS) to evaluate and screen available technologies using site-specific factors, prior to identifying appropriate candidate technologies. Informed application of case-history information or DSS software also will enable the site manager to project possible ranges of technology performance and associated costs.
Suitability and Relative Cost of Technologies for Remediation
of LNAPL-Contaminated Sitesa/ |
| Treatment Technology |
Contaminated Medium |
Soil
Vapor |
Vadose
Zone
(Soils) |
Capillary
Fringe
(Soils) |
Saturated
(Soils) |
Groundwater |
| In-Situ Technologies |
| Bioremediation/ Enhanced Bioremediation |
6/$$$ |
4/$$$ |
4/$$$ |
4/$$$ |
4/$$$ |
| Bioventing |
3/$ |
2/$ |
2/$ |
6/$ |
6/$ |
| Air Sparging/ Biosparging |
4/$$ |
3/$$ |
3/$$ |
4/$$ |
4,5/$$ |
| Pump-and-Treat (Containment) |
8/NA |
8/NA |
8/NA |
7/$$$ |
4,5/$$$ |
| Source Dissolution with Natural Attenuation |
1/$b/ |
1/$ |
1/$ |
1/$ |
1/$ |
| Permeable Reactive Barriers/Reactive Zones (Containment) |
8/NA |
8/NA |
8/NA |
5/$$ |
5/$$ |
| Soil-Vapor Extraction |
2/$$ |
3/$$ |
3/$$ |
6/$$ |
6/$$ |
| Thermal Enhancements/In-Situ Heating Methods |
4/$$$$ |
3/$$$$ |
3/$$$$ |
6/$$$$ |
6/$$$$ |
| Free-Product Recovery |
| Bioslurping |
3/$$ |
4/$$ |
4/$$ |
6/$$ |
5/$$ |
| Groundwater Depression/NAPL Pumping |
8/NA |
8/NA |
4/$$$ |
6/$$$ |
5/$$$ |
| Skimming |
8/NA |
8/NA |
4/$$ |
6/$$ |
6/$$ |
| Excavation and Ex-Situ Treatment/Disposal |
| Biopile |
3/$$ |
3/$$ |
3/$$ |
3/$$ |
6/$$ |
| Low-Temperature Thermal Desorption |
6/$$$ |
3/$$$ |
3/$$$ |
3/$$$ |
6/$$$ |
| Off-Site Disposal |
6/$$$ |
3/$$$ |
3/$$$ |
3/$$$ |
6/$$$ |
| a/ |
Information from Parsons (1998). |
| b/ |
Key to technology performance and cost as follow: |
| 1 |
Technology of first choice, usually lowest cost and effective; preferred remedy. |
| 2 |
Technology of choice if natural attenuation cannot be applied; usually a preferred remedy. |
| 3 |
Technology that may be selected if 1 or 2 cannot be applied; may be a preferred remedy. |
| 4 |
Technology that will provide some treatment, effectiveness uncertain; not a preferred remedy. |
| 5 |
Technology that may be effective for containment; not a preferred remedy. |
| 6 |
Technology may provide limited treatment but is not designed for this purpose - effectiveness uncertain; not a preferred remedy. |
| 7 |
No immediate impact expected, long-term improvement may occur as a result of application; not a preferred remedy. |
| 8 |
No impact anticipated; not a preferred remedy. |
| $ |
relatively inexpensive; $$ = moderately expensive; $$$ = relatively expensive; $$$$ = relatively very expensive. |
| NA |
not applicable. |
|
Suitability and Relative Cost of Technologies for Remediation
of DNAPL-Contaminated Sitesa/ |
| Treatment Technology |
Contaminated Medium |
Soil
Vapor |
Vadose
Zone
(Soils) |
Capillary
Fringe
(Soils) |
Saturated
(Soils) |
Groundwater |
| In-Situ Technologies |
| Bioremediation/ Enhanced Bioremediation |
6/$$$ |
4/$$$ |
4/$$$ |
4/$$$ |
4/$$$ |
| Bioventing |
4/$ |
4/$ |
4/$ |
8/NA |
8/NA |
| Biosparging |
6/$$ |
> 6/$$ |
4,6/$$ |
4,6/$$ |
4,6/$$ |
| Chemical Oxidation |
7/$$$ |
4/NA |
4/$$$ |
4/$$$ |
4/$$$ |
| Pump-and-Treat (Containment) |
8/NA |
8/NA |
8/NA |
6/$$$ |
5.6/$$$ |
| Source Dissolution with Natural Attenuation |
1/$b/ |
1/$ |
1/$ |
1/$ |
1/$ |
| Permeable Reactive Barriers/Reactive Zones (Containment) |
8/NA |
8/NA |
8/NA |
5/$$ |
5/$$ |
| Soil-Vapor Extraction |
2,4/$$ |
3,4/$$ |
3,4/$$ |
8/NA |
8/NA |
| Thermal Enhancements/In-Situ Heating Methods |
4/$$$$ |
3/$$$$ |
3/$$$$ |
6/$$$$ |
6/$$$$ |
| Free-Product Recovery |
| Cosolvent/Surfactant Extraction/Flushing |
6/$$$ |
6/$$$ |
6/$$$ |
4/$$$ |
6/$$$ |
| NAPL Pumping |
8/NA |
8/NA |
7/$$$ |
6/$$$ |
5/$$$ |
| Excavation and Ex-Situ Treatment/Disposal |
| Biopile/Ex-Situ Venting |
3/$$ |
3/$$ |
3/$$ |
3/$$ |
6/$$ |
| Low-Temperature Thermal Desorption |
6/$$$ |
3/$$$ |
3/$$$ |
3/$$$ |
6/$$$ |
| Incineration |
8/NA |
3/$$$ |
3/$$$ |
3/$$$ |
6/$$$ |
| Off-Site Disposal |
6/$$$ |
3/$$$ |
3/$$$ |
3/$$$ |
6/$$$ |
| a / |
Information from Pankow and Cherry (1996) and Parsons (2000a). |
| b/ |
Key to technology performance and cost as follow: |
| 1 |
Technology of first choice, usually lowest cost and effective; preferred remedy. |
| 2 |
Technology of choice if natural attenuation cannot be applied; usually a preferred remedy. Suitability is contaminant-specific. |
| 3 |
Technology that may be selected if 1 or 2 cannot be applied; may be a preferred remedy. Suitability is contaminant-specific. |
| 4 |
Technology that will provide some treatment, effectiveness uncertain; not a preferred remedy. Suitability is contaminant-specific. |
| 5 |
Technology that may be effective for containment; not a preferred remedy. |
| 6 |
Technology may provide limited treatment but is not designed for this purpose - effectiveness uncertain; not a preferred remedy. |
| 7 |
No immediate impact expected, long-term improvement may occur as a result of application; not a preferred remedy. |
| 8 |
No impact anticipated; not a preferred remedy. |
| $ |
relatively inexpensive; $$ = moderately expensive; $$$ = relatively expensive; $$$$ = relatively very expensive. |
| NA |
not applicable. |
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