-M.S. (Environmental Engineering Science) University of California, Berkeley, 1994
-B.S. (Chemistry and Biology) University of Arizona, 1991

Registrations/Certifications

RCRA Hazardous Waste Training Seminar, McCoy and Associates, 2004
UST and Water Quality Update Seminar, ENRS, State Bar of Arizona, 2004
OSHA 40-Hour Health and Safety Training for Hazardous Waste Operations, 1991
8-Hour HAZWOPER annual refreshers
MSHA Certified Mine Safety Training

Representative Experience

• Management of a Phase III Pilot Scale Study project for cleanup of soils and groundwater impacted by liquid phase petroleum hydrocarbons in Phoenix, Arizona. In addition to compliance with RAO’s, included comparison of effectiveness of bioventing, biosparging, nutrient addition, and anaerobic/aerobic cycling systems through interpretation of extensive field data. Work included use of tracers for evaluation of sparging effectiveness, porosity measurements, and mixing and movement of groundwater in the sparge zone.

• Assisted with projects involving deep soil vapor extraction (SVE) for protection and remediation of groundwater beneath arid landfills. SVE systems were configured to maximize removal of deep vadose zone volatile organic compounds (VOC) that had acted as a source to groundwater. Field work included collection of baropneumatic and pump test data for field air permeability and landfill gas generation measurements, plus well logging and installation. Interpreted soil gas analytical data, prepared landfill investigation report and presented findings to regulators.

• Project professional for continued field inspections of an engineered earthen cover designed to protect groundwater and eliminate potential surface exposure from chromium-contaminated soils.

• Worked on a nitrate loading paper study for a developer in Kingman, Arizona. Involved with interpretation of available groundwater hydrogeologic and analytical data.

• Took part in a large-scale EPA mediation process involving more than 20 sites contributing to a single groundwater plume. Evaluated sites with regard to source areas, contaminant definition and hydrogeology using site-specific Information Briefs. Performed an early cash-out option comparison with client facility.

• Performed field investigations at local landfills, including setup of barometric pressure and pneumatic pump tests and interpretation of soil gas analytical data. Performed logging, and oversaw drilling and well completion activities. Prepared landfill investigation report. Presented findings to regulators. Took part in the operation of a pilot-scale Soil Vapor Extraction system. The landfill projects included new techniques for preventing contaminants from moving to groundwater in arid regions, as well as site remediation.

• Managed a field investigation at a chemical plant. Performed Geoprobe soil gas and groundwater investigations. Interpreted permeability and analytical data and wrote report which included Site Cleanup Order recommendations for client.

• Worked on various groundwater and soils investigations. Project work included: UST leaks, historic chlorinated organic spills, the use of oxygen releasing compounds in wells to prevent gasoline migration, carbon dioxide concerns from acidic water reacting with aquifer carbonates, pit lake profiling studies, perennial creek investigation for the impact from an acidic mine-originating groundwater plume, and benzene migration via natural gas release.

• Took part in the investigation of a deep bedrock aquifer at a mine site. Sampled and tested new wells with a packer system and wrote up geochemical interpretation of findings. This project was part of the delineation of a very large high sulfate-, high metals-bearing groundwater plume within geologic formations having very different hydrologic properties.

• Managed and performed on-going groundwater monitoring at a mine site. Included scheduling, oversight, and large volume data collection and manipulation.

• Assisted with a field organic anion tracer injection, collected groundwater samples, and worked extensively with ion chromatography during a study at an EPA RCRA/CERCLA site. Performed on-site analytical procedures for soil gas, groundwater, and soil investigations in mobile laboratory units using gas chromatography.

• Worked on process engineering issues for new drug formulations manufactured using Bend Research technology. Oversaw manufacture of pre-commercial batches at a commercial pharmaceutical plant in Puerto Rico.

• Took part in contract research for the pharmaceutical industry. Wrote FDA-required documents and took part in meetings aimed at filing for approval of a drug formulation. Wrote numerous documents for technical transfer of a confidential spray drying technology to a major pharmaceutical company. Attended and wrote minutes for video conference meetings involving pharmaceutical dispersion technology. Wrote patent examples for new drug form technology.

• Evaluated drug solubilizers and performed speciation on drugs in solution using nuclear magnetic resonance (NMR) and HPLC for understanding of in vitro/in vivo correlation. Characterized structures using dynamic light scattering. Developed assay methods. Performed dissolution tests on drug materials in solution.

PROFESSIONAL PUBLICATIONS:

Fischer M.L., Bentley A.J., et al., Factors Affecting Indoor Air Concentrations of VOCs at a Site of Subsurface Gasoline Contamination, Environ. Sci. Technol., 1996, 30, 2948-2957.

Sedlak, David A. and Abra Bentley. The role of photochemistry in the transport and transformation of arsenic. Davis: University of California Water Resources Center, 1997; 13 p. (Technical completion report).