Engineering approach for tier 2 RBCA evaluations at NAPL-contaminated sites

Citation
D. Tomasko et al., Engineering approach for tier 2 RBCA evaluations at NAPL-contaminated sites, J WATER RES, 127(5), 2001, pp. 324-332
Citations number
29
Categorie Soggetti
Environment/Ecology,"Civil Engineering
Journal title
JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE
ISSN journal
07339496 → ACNP
Volume
127
Issue
5
Year of publication
2001
Pages
324 - 332
Database
ISI
SICI code
0733-9496(200109/10)127:5<324:EAFT2R>2.0.ZU;2-8
Abstract
Groundwater contaminated with non-aqueous-phase liquids (NAPLs) poses human health risks and evaluation of these risks requires estimated groundwater NAPL concentrations. Site NAPL concentrations are typically evaluated using the U.S. Environmental Protection Agency's tiered risk-based corrective ac tion (RBCA) system. Tier 1 uses conservative assumptions and little site-sp ecific data, while tier 2 requires more detailed site-specific data. This p aper presents an engineering approach that can be used to predict maximum g roundwater NAPL concentrations resulting from NAPL spills. This screening t ool was developed by deriving an analytical solution for a partial differen tial equation describing NAPL transport through the unsaturated zone. Model processes include dissolution, advection, dispersion, sorption, volatiliza tion, and first-order degradation. Results are obtained using two nondimens ional parameters and engineering plots for a wide range of conditions. A br ief study is provided to demonstrate the application of the model. Because the engineering plots are easy to use and facilitate sensitivity analyses, the model is recommended for screening and RBCA tier 2 analyses.