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Groundwater Hydrology

Groundwater quantity and quality issues affect the feasibility of proposed new facilities, the operation of active facilities, and closure of active facilities. S.E.T. specializes in the characterization of groundwater hydrology at proposed, active and closed facilities, with an emphasis on:

Numerical Modeling of Groundwater Flow and Contaminant Transport
Site Characterization Techniques

S.E.T. evaluates the complex groundwater flow characteristics and pathways. S.E.T. hydrogeologists and engineers are skilled at the development of site-specific conceptual and numerical models of groundwater hydrology, and the presentation of model results and predictions to the regulatory community.

Flow Transport Modeling

S.E.T. has developed numerical flow and transport models to support permit applications, design, and select remedial alternatives, and develop risk assessments. We have experience dealing with complex environments where faults and fractures, multiple production/pumping wells, mine workings, and open pits affect groundwater flow paths.

S.E.T. optimizes each stage of the modeling process, including:

Conceptual model development
Model selection
Model set-up
Calibration
Prediction
Sensitivity analysis

S.E.T. believes that careful development of the CONCEPTUAL MODEL will streamline and focus the remaining steps of the modeling process. The conceptual model must identify all potential flow pathways and anticipate key processes that affect site hydrogeology.

Model Boundary

Water Levels

MODEL SELECTION is a critical step in a successful modeling strategy. S.E.T. evaluates myriad numerical and analytical model approaches and selects that which satisfies budgetary and regulatory constraints while handling difficult or unusual site conditions, such as: fracture flow, stream-aquifer interaction, unsaturated/saturated flow paths, dewatering, and groundwater mound development.

MODEL SET-UP can be time-consuming and prone to costly errors and delays. S.E.T.'s expertise in database development enables organization of field data into a structure that facilitates model development, enhances quality assurance/quality control, and integrates one or more numerical models for groundwater flow, solute transport, and particle tracking.

S.E.T. developed automated programs that expedite the CALIBRATION process. Automated programs were used to calibrate a regional groundwater flow and transport model of a site in southern Arizona, where infiltration of excess mine water below an evaporation pond created a groundwater mound.

PREDICTION quantifies the response of the modeled system to future events. Numerical models can be used to predict hydrologic responses to changes in aquifer conditions, such as the development of a cone of depression due to dewatering, the capture zones of groundwater extraction wells, or the future extents of contaminant plumes under various remedial alternatives.

SENSITIVITY ANALYSIS is a critical, yet often overlooked, step in providing a defensible model. S.E.T. adheres to guidelines established by the American Society of Testing and Materials (ASTM) to determine the type of sensitivity exhibited by the model.

Site Characterization/Baseline Studies

A well-targeted site characterization or baseline study is necessary to support a numerical modeling study or to develop a site management or remediation plan. S.E.T. is experienced at conducting hydrogeologic field characterizations and developing conceptual models, databases, and using advanced visualization techniques.

S.E.T. will tailor field data collection programs to site-specific conditions, constraints, and data quality objectives. S.E.T. team members have conducted field characterization programs using equipment such as rotary, auger, and sonic drilling rigs, cone penetrometer testing (CPT) rigs, and direct push sampling equipment.

S.E.T. also conducted a baseline study in a copper mine consisting of open pits and over 1,600 miles of underground workings in Southern Arizona.

For baseline study, S.E.T. characterized site hydrogeology, geochemistry, and surface water by hydrology, and assessed regulatory compliance of site facilities. The S.E.T. team used MEDSYSTEM software to develop three-dimensional projections of the underground workings that can be used to develop framework for the conceptual and numerical needs of the site.