Doug Gray

Principal Project Manager,
Innovative Remedial Technologies Group Manager, AECOM

Mr. Gray has 37 years of project management and engineering experience focusing on the development, design, costing, and optimization of state-of-the-art, innovative remedial alternatives, site assessments, remedial alternative evaluations, remedial investigations, and feasibility studies. Mr. Gray is the Innovative Remedial Technologies Leader for several of AECOM’s key clients and looks to advance innovative technologies geared towards providing more cost effective remedial solutions and value-added services for the client. Mr. Gray provides technical remediation-related support to multiple offices and regions throughout AECOM. Also currently serving as the AECOM Midwest Region Technical Excellence (TE) Lead and as Co-Leader of the AECOM CCR Remediation Technical Practice Group (CCR-Remediation TPG).

Professional History
05/1992 – Present, AECOM Environmental Engineer
03/1984 – 05/1992, Dow Chemical Senior Environmental Engineer

BS, Chemical Engineering, Ohio State University, 1984
Technical Specialty, Reservoir Engineering,
The Ohio State University/NGWA, Credential in GW Science, 1992

Years of Experience
With AECOM: 28
With Other Firms: 9

Professional Affiliations
National Ground Water Association

OSHA HAZWOPER 40-Hour Training
OSHA 30-Hour Construction Safety Training
OSHA 10-Hour Construction Outreach Training
OSHA HAZWOPER 8-Hour Supervisor Training
PA Department of Environmental Protection – 2003 Land Recycling Program (Act 2) Client Workshop
Multiple GW Assessment and Remediation Training Classes

Certified Groundwater Professional
AECOM Project Management Certification Training

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In-situ Geochemical Stabilization (ISGS) of DNAPL

The ability to significantly mitigate the impacts of DNAPL in the subsurface from a reduction of mass flux and/or dissolved phase concentrations in groundwater is paramount with respect to implementing technically/cost-effective remediation. The study was conducted in two phases 1) bench-scale study to assess the reactivity/performance of several ISGS formulations with site-specific material; & 2) field pilot study to field test the successful results obtained in the bench-scale study. The pilot study provided field-scale data to evaluate 1) field-scale applicability of ISGS; 2) mass flux reductions; 3) field-scale implementability; 4) compositional changes in groundwater and DNAPL and 5) overall applicability of this technology for other potential applications. Site-specific soil and groundwater were used in the bench-scale study in both batch and column reactors. The field-scale pilot consisted of a 5600 ft2 and 10 ft. thick treatment area within a known and delineated area of DNAPL in the subsurface. Both existing and new monitoring wells were utilized in the pilot. Similar testing was completed for both studies, along with additional evaluation of radius of influence and field implementability for the pilot. The bench study results indicated hydraulic conductivity reduction of up to 2-3 orders of magnitude; concentration reductions of VOC and SVOC constituents in the DNAPL and reduced mass diffusion from the DNAPL to dissolved phase. The field pilot was subsequently implemented, and performance monitoring was completed. The evaluation of post-ISGS amendment addition soil/groundwater and DNAPL data indicates reduction of hydraulic conductivity of 1-2 orders of magnitude, reductions in observed DNAPL thickness in the treatment grid, and compositional changes in both the DNAPL and groundwater. The complete evaluation of the bench-scale study and field-scale pilot results will be presented and lessoned learned.