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Research on NAPL Source Zones
The remediation of subsurface formations contaminated by non-aqueous phase liquids (NAPLs) is a major impediment to the restoration of many hazardous waste sites. NAPLs are classified as those lighter than water (LNAPL) or denser than water (DNAPL) and can serve as long-term sources of contamination impacting both ground water and surface water. Conventional remediation techniques designed for dissolved contaminant removal have proven inadequate for achieving acceptable environmental cleanup goals within reasonable time frames for NAPL-contaminated source zones.
Field-scale research has demonstrated that a high percentage of
NAPL mass can be rapidly depleted within source zones by using
aggressive in-situ thermal or chemical flushing technologies. Even
with these aggressive technologies, the efficiency of NAPL depletion
often decays exponentially with increasing mass removed and complete
NAPL removal may not be technically or economically feasible. For
such sites, the key questions are: 1) how much NAPL must be removed
to be protective of human health and the environment, and 2) are
current technologies adequate to achieve this level of removal.
To answer these questions, we must understand the relationships
between NAPL mass depletion, contaminant mass flux from the source
zone, and dissolved plume properties.
GWERD research is focused on three critical aspects:
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GWERD conducts applied and fundamental research to further develop source zone remediation technologies and to understand the relationship between source zone mass removal and risk reduction.
Click here for related research
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Projects
- Impacts of DNAPL source zone treatment (PDF) (1 pg, 27K) : Experimental and modeling assessment of the benefits of partial source removal. Contact: Lynn Wood (wood.lynn@epa.gov)
- Field demonstration of the
solvent extraction residual biotreatment technology (PDF) (1 pg, 416K).
Contact: Susan Mravik (mravik.susan@epa.gov)
- Steam injection into fractured
bedrock at Loring Air Force Base (PDF) (1 pg, 89K).
Contact: Eva Davis (davis.eva@epa.gov)
- Enhanced source removal (PDF) (1 pg, 20K). Contact: Lynn Wood (wood.lynn@epa.gov)
Publications
- Kavanaugh, M.C., P.S.C. Rao, and A.L. Wood. 2003. The DNAPL Remediation Challenge: Is There a Case for Source Depletion? (PDF) (129 pp, 1.1MB) (EPA/600/R-03/143)
- Davis, E. 1998. Steam Injection for Soil and Aquifer Remediation (PDF) (16 pp, 646K) (EPA/540/S-97/505)
- Davis, E. 1997. How Heat can Enhance In-situ Soil and Aquifer Remedation (PDF) (18 pp, 91K) (EPA/540/S-97/502)
- Mravik, S.C., R.K. Sillan, A.L. Wood and G.W. Sewell. 2003. Field Evaluation of the solvent extraction residual biotreatment technology. Environ. Sci. Technol. 37: 5040-5049.
- Jeong, S.-W., A.L. Wood and T.R. Lee. 2003. Enhanced removal of DNAPL trapped in porous medial using simultaneous injection of cosolvent with air: influencing factors and removal mechanisms. J. Hazardous Materials B101: 109-122.
- Huling, S.G., R.G. Arnold and R.A. Sierka. 2001. Influence of Peat on Fenton Oxidation. Water Research 35 (7): 1687-1694.