Characterization and numerical simulation in support of LNAPL recovery in the presence of a fluctuating water table

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:569953

Mazalan, P; Lyverse, M ^[1]; Kuehne, D ^[2]

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1. Chevron Research and Technology Co., Hooven, OH (United States)
2. Chevron Research and Technology Co., Richmond, CA (United States)

A site characterization and numerical simulation study was undertaken to aid in the design of LNAPL recovery systems at a former refinery near Cincinnati, Ohio. The primary goal of the study was to help optimize removal of remaining mobile LNAPL from the site, concentrating on local {open_quotes}hot spots{close_quotes} where contaminant mass removal can be maximized and significant risk reduction can be achieved. A {open_quotes}pump and treat{close_quotes} system has been in place at the site since 1985. To date, over 3.3 million gallons of LNAPL (80% leaded gasoline/20% diesel) have been recovered from an unconfined aquifer consisting of sand and gravel. Fluctuation in the local water table elevation, which has a range of 10 feet, has produced a large LNAPL {open_quotes}smear zone{close_quotes}. LNAPL recovery rates from existing recovery wells have been strongly correlated to changes in the local water table elevation. Prerequisites for accurate numerical simulation at this location included a realistic description of LNAPL saturation in the aquifer, appropriate data to describe aquifer material and fluids for flow simulation, and the ability to incorporate a fluctuating water table in the simulations. Programs completed in this study include: (1) site characterization to describe LNAPL distribution using laser induced fluorescence (LIF) and cone penetrometer logs, (2) continuous coring through the {open_quotes}smear zone{close_quotes} identified by the LIF log, (3) laboratory analysis of core material and associated fluids to provide parameter definition for numerical simulation, and (4) calibration and predictive simulation using a finite difference oil field reservoir simulator. LIF data proved invaluable for providing a continuous, high-resolution description of the vertical distribution of LNAPL.

• OSTI ID: 569953
• Report Number(s): CONF-971116--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
GROUND WATER
MATHEMATICAL MODELS
NONAQUEOUS SOLVENTS
REMEDIAL ACTION
SITE CHARACTERIZATION