Construction and Mine Dewatering

John J. Ward, RG, Groundwater Consultant

In analyzing construction and mine dewatering, my focus is on incorporating of regional hydrogeologic conditions into development of useful site-specific data, analyzing and interpreting hydraulic testing, flow modeling, and optimizing the dewatering systems.

Special attention is paid to the occurrence of localized flow systems, such as fractured or coralline rocks, or conduits such as buried pipe embedment or open-work drainage systems, which may dominate dewatering efforts.

SELECTED CONSTRUCTION AND MINE DEWATERING EXPERIENCE

  • Open Pit Mine Dewatering, Altiplano Region, Mexico:  Conducted hydrologic testing and developed regional and mine-site groundwater models to predict dewatering rates, pit lake recovery, and regional impacts. Assisted in permit applications. Mine now in operation.
  • Construction Dewatering, Sewage Lift Station, Arizona:  Testifying expert for contractor on differing site conditions dispute, dewatering of deep sewage lift station.  Assisted in trial prep., provided deposition testimony.  Settled.
  • Construction Dewatering Pipeline, Arizona:  Proposed construction within highly permeable Salt River gravels. Tested effects of sumping vs. predrainage methods, alternatives budgeting, and groundwater modeling of dewatering strategies.
  • Interstate Highway I-105 Dewatering, California:  Developed predictive groundwater model to locate new wells, predict impacts of contaminated water rising into depressed section of I-105. Developed more effective dewatering alternatives.
  • Feasibility of Mine Dewatering, Nevada:  Conducted peer review and independent assessment of open pit dewatering, Nevada. Provided due diligence for permit app.
  • Contaminated Site Dewatering, California:  Managed characterization of solvents in soil and groundwater. Designed and constructed groundwater dewatering system for contaminant control. Conducted fate analysis of contaminants. Obtained no further action site (NFA) closure.
  • Open-Pit Mine Dewatering and Recharge, Florida:   Tested and constructed two open-pit phosphate mine dewatering and groundwater recharge systems, Central Florida.
  • Abandoned Mine Redevelopment, Arizona:  Conducted due diligence of closed open-pit mine. Assessed groundwater inflows to pit, evaluated dewatering effectiveness and pressure relief wells on stabilizing pool elevations and pit walls.
  • Pipeline Dewatering, Hawaii:  Performed critical analysis of ongoing pipeline construction and dewatering.  Testifying expert for owner in differing site conditions dispute.
  • Mine Tailings Dewatering, New Mexico:  Conducted fate and transport analysis using modeled flow and transport in molybdenum mine tailings.  Evaluated feasibility of dewatering tailings and blocking mine water discharge.
  • Mine Tailings Dewatering, Wyoming:  Characterized groundwater potential to contaminate perennial streams from mine tailings, Wyoming.  Evaluated dewatering performance and impacts to groundwater.
  • Construction Dewatering, Hawaii:  Designed and managed dewatering pilot testing for Honolulu waterfront development. Installed dewatering wells in open-work coral deposits. Conducted aquifer tests to determine dewatering rates and duration.
  • Cooling Water Disposal, Hawaii:  Designed and installed deep recharge wells for cooling water disposal at two power plants, Hawaii.
  • Brine Depressurization, New Mexico:  Determined sources of brine contamination river and downstream reservoirs.  Determined feasibility of dewatering and depressurization of brine aquifer.