WRRCTR No.174 Trace Organic (DBCP) Transport Simulation of Pearl Harbor Aquifer, Oahu, Hawaii: Multiple Mixing-Cell Model, Phase I

dc.contributor.author Orr, Shlomo en_US
dc.contributor.author Lau, L. Stephen en_US
dc.date.accessioned 2008-07-17T23:02:44Z
dc.date.available 2008-07-17T23:02:44Z
dc.date.issued 1987-08 en_US
dc.description State of Hawaii, Office of Environmental Quality Control, Department of Health Grant/Contract No. T-377 en_US
dc.description.abstract Lumped parameter models were chosen to provide a preliminary appraisal of the fate of trace organics (DBCP) in a portion of the Pearl Harbor aquifer and to provide a management tool for policymaking. The models, which consider portions of the aquifer as mixing cells, extensively simplify the systems. Special attention focused on attenuation and travel time in the approximately 800 ft (244 m) thick, vadose zone. Pseudo first-order decay coefficients determined from pesticide residues in the topsoil were used to determine attenuation in the vadose zone. A separate mixing-cell model was developed for the topsoil to distinguish between the different mechanisms responsible for the attenuation of adsorbed pesticides, particularly leaching vs. volatilization. Thus, an alternative method that excludes the varying distribution coefficients is suggested to estimate the leaching fraction of strongly adsorbed pesticides. The results indicate that at least a decade will pass before the aquifer starts to recover and another five years before DBCP concentrations become undetectable. The concentration attenuation within the vadose zone is about three orders of magnitude greater than the concentration reduction resulting from dilution within the aquifer. The simulated concentrations are very sensitive to the decay coefficients determined for the unsaturated zone. We conclude that leachate concentrations as low as 0.1 ppb (pg/l) below the top few feet of soil can reach and contaminate deep groundwater, where (usually) the dilution is limited to less than 1: 10. Due to the high persistence of many volatile organic carbons (dissolved in water) in very low concentrations, they can be considered as "conservative" tracers for modeling purposes. en_US
dc.format.extent ix + 60 pages en_US
dc.identifier.citation Orr S, Lau LS. 1987. Trace organic (DBCP) transport simulation of Pearl Harbor aquifer, Oahu, Hawaii: multiple mixing-cell model, phase I. Honolulu (HI): Water Resources Research Center, University of Hawaii at Manoa. WRRC technical report, 174. en_US
dc.identifier.uri http://hdl.handle.net/10125/2021
dc.language.iso en-US en_US
dc.publisher Water Resources Research Center, University of Hawaii at Manoa en_US
dc.relation.ispartofseries WRRC Technical Report en_US
dc.relation.ispartofseries 174 en_US
dc.subject aquifers en_US
dc.subject organic pesticides en_US
dc.subject model studies en_US
dc.subject groundwater en_US
dc.subject saturation zone en_US
dc.subject vadose water en_US
dc.subject mixing-cell model en_US
dc.subject DBCP en_US
dc.subject EDB en_US
dc.subject TCP en_US
dc.subject Mililani Wells en_US
dc.subject basaltic aquifer en_US
dc.subject Pearl Harbor aquifer en_US
dc.subject Oxisols en_US
dc.subject Ultisols en_US
dc.subject Lahaina en_US
dc.subject Wahiawa en_US
dc.subject Leilehua soils en_US
dc.subject Maui en_US
dc.subject Hawaii en_US
dc.subject Oahu en_US
dc.subject.lcsh Dibromochloropropane -- Hawaii -- Oahu -- Environmental aspects. en_US
dc.subject.lcsh Groundwater -- Pollution -- Hawaii -- Oahu. en_US
dc.subject.lcsh Groundwater flow -- Hawaii -- Oahu. en_US
dc.subject.lcsh Organic water pollutants -- Hawaii -- Oahu. en_US
dc.title WRRCTR No.174 Trace Organic (DBCP) Transport Simulation of Pearl Harbor Aquifer, Oahu, Hawaii: Multiple Mixing-Cell Model, Phase I en_US
dc.type Report en_US
dc.type.dcmi Text en_US
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