Waste Management of Colorado, Inc:
County Line Landfill, Douglas County, Colorado
Scope: HCI constructed a numerical model to evaluate whether leachate from the landfill posed a risk to nearby municipal water-supply wells. The model simulated geologic formations of the Denver Basin into which the municipal wells are completed. Transport of dissolved chemicals was simulated for 100 years into the future. Results of the modeling provided a foundation for decision making for State and county agencies.
HCI also investigated areas immediately north of the landfill to delineate contamination in the shallow ground water using an on-site gas chromatograph. Based on results of the field screening and subsurface characterization from drilling, a ground-water remediation system was selected and installed.
HCI designed and installed a ground-water interceptor trench and a collection system to capture dissolved chemicals within a shallow ground-water plume. The system made use of contrasting geologic units to freely drain ground water above a low-permeability claystone. The system, which collects ground water at a rate of six gpm, was installed for less than $100,000 and has successfully prevented migration of the plume.
Role: At the beginning of the project I was the project manager constructed a MODFLOW model to resolve a dispute between the mine and a rancher. HCI was retained as their consultant for the scope mentioned above, for this scope I developed the finite element numerical model, which is still in use by HCI. I coupled the flow model with the solute transport model for the WAD cyanide plume investigation and participated in the design and ran all needed simulations. I designed and supervised the installation of a flume network in natural streams to investigate the infiltration capacity of the natural courses within the hydrologic basin.
Burlington Northern and Santa Fe Railway:
West Burlington Locomotive Repair Facility, West Burlington, Iowa
Scope: HCI completed a supplemental remedial investigation on a 1200-acre parcel where a locomotive repair facility has operated for approximately 75 years. The objective was to characterize the presence of organic and metal constituents in surface water, ground water, sediments, and soil. Site investigations included the installation of 14 Waterloo in bedrock coreholes in addition to installationÔMulti-Level Sampling Systems of traditional monitoring wells and piezometers. The multi-level system and monitoring wells provided an initial means for obtaining geologic information (e.g., fracture spacing, aperture) and ground-water quality. The water quality data revealed the presence of non-aqueous phase (DNAPL) tetrachloroethylene (PCE) at depths of 185 feet in a fractured limestone/dolomite aquifer. Detailed geologic information revealed that the DNAPL PCE moved downdip but upgradient (from a ground-water flow perspective) from the PCE handling facility; and had descended along a fracture pattern to a low point on top of a shale aquitard.
For this project, HCI developed specific protocols for water-quality sampling that are different than USEPA standard sampling protocols. The changes in protocol were necessary because purging three to five casing volumes of water would have produced mixing of the hydrogeologic zones. HCI also developed protocols for isotope sampling that aided in determining sources of water.
Based on the geologic and water-quality information at the facility, a ground-water flow and solute transport model was developed to simulate flow and transport over a three-square mile area. The model was used to predict the movement of organic compounds for a 30-year period of time. HCI also performed a focused analysis of remedial options and demonstrated that no cost-effective option existed to remediate ground water. The modeling work also showed that no users of the aquifer would be adversely affected by a “no action” alternative.
Results from the field and modeling investigations were submitted to the Iowa Department of Natural Resources (IDNR), and provided a foundation for regulatory decision making. The IDNR accepted HCI’s recommendation of continued surface-water and ground-water monitoring at the facility, and agreed that ground-water remediation was neither cost effective nor necessary. Consequently, HCI prepared, and is implementing, a site-wide, five-year water quality monitoring program.
Role: I constructed the numerical model, coupled with solute transport, and ran all required simulation. I designed piping and treatment system to treat all the VOC by gas stripping for feasibility level.
Union Pacific Railroad Dompany:
Scope: HCI is performing a series of analytical solution in litigation support to assess the extent and the fate of PCE and TCE contaminant at an old railway station which also used to receive PCE from a nearby dry-cleaner house.
Role: selected appropriate analytical technique and computer program to solve the one-dimensional solute transport model.
Union Pacific Railroad:
Scope: HCI constructed a detailed ground-water flow and solute transport model to evaluate the fate and transport of volatile organic compounds in the area around the Sacramento Railyard. The models have been used to focus remedial investigation activities and to assist in evaluating and selecting cost-effective remedial designs for extracting organic compounds from ground water. As part of the modeling effort, HCI geochemists conducted field and laboratory measurements to estimate the rate of degradation of chlorinated volatile organic compounds.
Role: I constructed the numerical model, coupled with solute transport, and ran all required simulation. I investigated the fate of the plume and test the impact of dewatering activities in city center.
Client Confidential:
Scope: HCI is currently evaluating the dewatering practices at two diamond mines that have evolved from surface to underground operations. We re-designed and expanded the field data collection program and developed a ground-water model to evaluate various options (including method and timing) of dewatering the very water-sensitive kimberlites pipes.
Role: I was the project manager and constructed the numerical model, which is still in use by HCI.
Barplats Mines Limited/Impala (Barplats):
Scope: A three-dimensional, finite element ground-water flow model has been developed by Hydrologic Consultants, Inc. of Colorado (HCI) to predict the dewatering requirements for re-opening and expanding of the Crocodile River Mine (CRM) and the potential drawdown in the nearby water table induced by the dewatering. The mine is composed of old submerged workings and proposed open cast and extensive underground workings. The model was based on geologic data provided by Barplats and hydrogeologic data collected by KLM Consulting Services (KLMCS).
Important hydrologic components incorporated into the model include the basic geologic framework including the Commando and Eastern dykes, the old and proposed new mine workings, the Hartbeespoort Reservoir, the Crocodile River, rainfall, and infiltration of irrigation from wells and channel diversion.
Role: I was the project manager I constructed the numerical model and produced needed documentation.
Client Confidential:
Scope: HCI built a large, fully three-dimensional, finite-element, ground-water flow model numerical model to predict the quantity of water discharge from a diamond mine in northern Canada that is situated under a lake. To predict the quantity of discharge of the proposed mine the mining plan and the changes in hydraulic conductivity in surrounding rock mass was incorporated in the numerical model. The model was used to define the potential amount and distribution of ground-water inflow to the various mine workings over time under the currently proposed mine plan. The hydrologic model was coupled to a solute transport model to predict the changes in the percentage of Lake Water versus connate water. Particle tracking technique was used to predict the fate of mine contaminated water.
Role: I was the project manager, constructed the numerical model, and provided all the simulations and analysis of model output. The model is still in use by HCI and the client.
