Fate and transport modeling to negotiate site-specific cleanup goals and to design/ enhancement of groundwater pump and treat systems.
Ms. Quinn has used a variety of analytical and numerical models to simulate fate and transport of contaminants in vadose zone soil, and in groundwater, as follows:
- Vadose Zone Fate and Transport Modeling – For several sites, including a former Unocal chemical storage terminal and the Air Force Plant 42, Ms. Quinn used fate and transport modeling to develop soil screening and clean-up values that are higher than conservative levels provided in RWQCB-LA Region guidance, without posing a risk to groundwater. The regulatory agencies agreed to the approach, which involved analysis using the VLEACH model at tremendous cost savings for the clients.
- Puente Valley Operable Unit (PVOU) Steering Committee Model Benchmarking – As Senior Hydrogeologist, on behalf of USEPA Region IX, Ms. Quinn reviewed input data and calibration results of a model prepared by the PVOU Steering Committee’s consultant and prepared an independent model using CFEST to benchmark the results. The benchmarked model enabled USEPA and the PVOU Steering Committee to work closely together in refining alternative remediation strategies, and provided USEPA with increased confidence in the Steering Committee’s efforts.
- Basin-wide San Gabriel numerical CFEST model refinements – As Lead Hydrogeologist, Ms. Quinn refined the basin-wide San Gabriel numerical CFEST model to assess groundwater flow and solute transport conditions in the South El Monte Operable Unit and Whittier Narrows. Ms. Quinn designed an extraction well network to intercept groundwater contamination migrating toward the Central Basin. Wells were installed using model-derived location, production capacity, and construction specifications.
- North Hollywood Operable Unit (NHOU) Extraction Wellfield Evaluation – Ms. Quinn critiqued the production performance of a 2,000-gpm extraction well remediation system, the NHOU extraction wellfield, and evaluated the effectiveness of the system in containing TCE and PCE groundwater contamination. The evaluation included: development of a hydrologic budget; design of aquifer testing; and capture zone and drawdown modeling. The effects of lower water levels on remediation extraction well capacity, and related influence on the capture zone created by the remediation system, were evaluated.
- El Toro Marine Corps Air Station, Irvine Sub-basin Model – Using MODFLOW, Ms. Quinn developed a 3D flow model to evaluate remedial alternatives for groundwater contamination, including interpretation of lithologic, geophysical, piezometric pressure, and groundwater chemistry data from hundreds of production and single point and multiport monitoring wells throughout the Irvine Sub-basin, and development of a regional conceptual model that became the basis of a calibrated numerical model. Particle tracking was performed to evaluate vertical flow rates and to develop alternative shallow extraction scenarios effectively balanced with deep groundwater production from the Sub-basin to contain regional TCE groundwater contamination in the area.
- Raymond Basin Conjunctive Use Water Supply Management Program – As task manager of Hydrogeology, Ms. Quinn developed conceptual basin operational schemes and a basin-wide ground water flow model using CFEST to simulate and compare artificial recharge and recovery scenarios for drought protection. Geologic properties, historical hydrogeologic patterns, and well capacity information are some of the features Ms. Quinn assimilated into a 3D finite element groundwater flow model for the basin by interfacing GIS data. Ms. Quinn employed the CFEST modeling code to simulate the effect of specific basin operational schemes on groundwater conditions within the basin over projected time intervals.