WET's professionals possess valuable experience from many projects throughout the environmental industry in both the private and public sectors. These experiences were compiled on current WET projects, as well as projects perfomed with other reputable firms throughout their work careers. WET's principals work closely with federal, state, and local regulatory personnel to ensure that project goals coincide with environmental law. As a result, our multi-disciplined project team allows us to adapt to the needs of each project, and to ensure that a high quality and cost effective solution is reached.
Projects completed have ranged from small site assessments for private landowners, to turnkey environmental services for multi-national corporations. To provide specific examples of projects within our service areas, we have selected the following project summaries from both current and past projects completed by WET staff members.
The County Landfill first documented ground water contamination in the 1980’s in the county shop’s water supply spring. Follow-up investigations installed a total of 17 monitoring wells that defined the solvent plume, but failed to define the source of contamination or feasible remedial alternatives for the site.
A State of the Technology investigation by WET personnel employed both seismic refraction techniques to define the bedrock/alluvium contact and direct push technology to define the bedrock fractures transporting contamination. This investigation allowed a complete hydrogeologic understanding of the site. Bedrock fractures were transporting PCE, TCE, and DCE from the footprint of the landfill, up the dip of the formation into the aquifer. These contaminants were then flowing through the fractured bedrock into the alluvial valley and showing up as surface and subsurface springs and seeps in the alluvial valley.
These data allowed a specific, focused remedial effort using in-situ air sparging and funnel-and-gate methods. One area was treated with a well point sparging system to target specific subsurface fracture zones, while another area with widespread contamination, employed a sheet-pile funnel system to direct the ground water through a subsurface sparging system.
Using the detailed hydrogeologic information from the site investigation and remediation system installation, a transient three-dimensional ground water flow and contaminant transport model and a two-dimensional vadose zone model were developed. The models provided insights into effective remedial technologies and litigation support for a lawsuit between the County and party identified as dumping hazardous waste into the landfill. Given the complex fractured bedrock, surface and subsurface springs and seeps, and interaction with surface water, the modeling effort was very complex.
WET’s project manager served as lead expert witness for the jury trial of the lawsuit. The litigation resulted in payment of past and future projected remediation expenses for Park County.
A complete understanding of geologic and hydrogeologic conditions has allowed WET personnel to install and operate an economical monitoring and remediation system for the landfill.
WET was contracted to perform Phase II Site Assessments at Client's facilities throughout Montana and Colorado. Initial sites included 14 Stations in Montana and 7 in Colorado. The assessments were performed as part of a property transaction to identify the presence or absence of hydrocarbon contamination associated with the UST systems at each site. In Montana, assessments were completed at 10 sites within a four-day period, with soil and ground water samples being collected for laboratory analysis. All 14 site investigations and investigation reports for the Montana sites were completed within a three-week deadline. In both Montana and Colorado, WET has assumed Phase III remedial investigation and design work.
Many sites contained significant ground water and soil contamination and required follow-up remedial action. Remedial Investigations were conducted to define the extent and magnitude of the hydrocarbon plumes, to ensure proper placement of monitoring wells and other remediation components. Sites Many sites have been fully investigated and closed to further remedial action. WET worked closely with the MDEQ and Colorado Oil Inspection Section, to ensure that site work proceeded in a timely and cost effective manner, while still meeting all applicable State cleanup standards. WET also provided and completed petroleum reimbursement documentation for each site, and supported the Client to ensure eligibility. Replacement of leaking USTs, removal of non-compliant USTs, remedial pilot studies, remedial action, and long term monitoring are still ongoing at various sites in both states.
WET provided litigation support and on-site investigation services for a small meat packing plant located near a railyard site in central Montana. After the railroad's contractor completed the site investigation, WET Personnel were contracted by the private landowner to further investigate the property to determine if waste materials were deposited on the property. Industrial sludges and batteries were discovered on the property. WET characterized the volume of waste material and the contaminants present in the disposal area, and submitted a short report to the Client and MDEQ reporting our findings.
A faulty siphon valve on a UST resulted in a continuous gasoline release over a period of time at a Montana auto dealer's facility. Site investigation revealed significant soil and groundwater contamination, as well as a free product plume. Geologic stratigraphy at the site consisted of medium to coarse sand and decomposed granite in the vadose zone, with a clayey silt layer interbedded with medium to coarse sand lenses through the water table, approximately 20 feet below ground surface. A multi-phase remediation system was installed at the site, including free product recovery, pump and treat, vapor extraction, and air sparging components. After free product was removed from the site and the contamination plume had stabilized, the remediation system was enhanced to more rapidly reduce hydrocarbon concentrations below MDEQ closure standards. An innovative air injection/vapor extraction combination well technology was implemented to provide complete coverage of the plume in a cost effective manner. Operation of the remediation system and site monitoring are ongoing.
WET is currently the prime contractor for the characterization and remediation of a free-phase and dissolved-phase hydrocarbon plume at a county maintenance facility. Remedial investigation activities included the delineation of co-mingling gasoline and diesel plumes encompassing an area 1,000 feet long by 400 feet wide, with an average free-phase thickness of 1.5 feet. Additional activities included free-phase liquid recovery tests, ground water slug tests, characterizing plume migration patterns to predict contaminant transport pathways, and identification of alluvial deposits, with coarsening downward sequences, and overbank deposits. Both auger drilling and direct push technologies were utilized in the site characterization. A multi-well product recovery system is in the process of being installed.
Contracted by a County Health Department, WET is currently conducting a nutrient sampling and analysis plan of a watershed lying within a Federal Superfund Site. Project tasks include background research of historical sampling data and watershed parameters, monthly and stormwater sample collection at various locations throughout the watershed, analysis of current and past sample data, and the preparation of a final report summarizing the results of the plan. Phase I goals of the project are to identify point source and non-point source loading of nutrients into the watershed, in order to meet target levels of a Voluntary Nutrient Reduction Program (VNRP) implemented by the county.
WET Personnel have provided preliminary assessment, remedial investigation, and remedial action services for a multi-national agricultural company in a three State region (Montana, Idaho, and North Dakota). These services were related to pesticide, herbicide, and fertilizer releases at grain elevators and other agricultural related facilities. Each site required a preliminary assessment to identify potential areas impacted by releases of chemicals, a remedial investigation to define the extent of contamination in soil and/or ground water, and a site analysis to classify receptors and risks. A Remedial Action, usually involving excavation and RCRA disposal, was completed at each site. If ground water was encountered, a complete investigation identifying the extent and magnitude of ground water contamination was completed.
WET Personnel have completed 17 sites in Montana and two in North Dakota. One site in North Dakota is currently active.
An Aboveground Storage Tank (AST) farm in a National Park experienced a release of several thousand gallons of Diesel #5 heating oil. The spill occurred in a remote location with a fragile surrounding ecosystem and a complex geologic structure, resulting in extensive soil contamination. The site contained limited access, minimal utilities, and was several hundred miles from the nearest disposal facility. Due to these site complications, various traditional remediation methods were not feasible. In order to minimize disturbance to the surrounding environment, an in-situ bioremediation system was designed to naturally degrade hydrocarbons in the soil. A bench scale pilot study identified multiple hydrocarbon-degrading bacterial strains in the soil. A biocell was designed to fully encapsulate the contaminated material and provide optimal conditions for bioremediation to occur. The project design required minimal transportation and handling of the contaminated soil, and also avoided long haul routes and disposal complications associated with other remedial methods.
WET personnel have provided monitoring services for municipal, industrial, and hazardous waste landfills in Montana, Wyoming, and Oregon. Services include field sampling, hydrogeologic reporting, and statistical analysis of monitoring data in compliance with Subtitle D regulations. Where past data quality or contamination problems have occurred, WET has the experience and expertise to troubleshoot sampling methods or complete investigations to put sampling programs back on track. WET provides a sample crew with a Hydrogeologist for the field sampling. By including professional personnel, data quality and documentation of unique field conditions is ensured. The same professional completes all reporting requirements and regulatory interactions.
Large settling ponds at the facility have received ash for over twenty years. The addition of over 400 acres of surface water ponds has impacted; not only the ground water, but also the desert environment. These impacts include TDS concentrations exceeding 200,000 ppm and the creation of several hundred acres of wetlands. WET was retained to model these impacts and predict the future impact resulting from an additional 20 years of use.
The site was very difficult to characterize and model due to the following conditions:
Complex geology - multiple (4) bedrock aquifers, alluvial channels, and faults
Naturally occurring constituents
Complex surface water features – wetlands, evaporation basins
Large industrial site with many potential source areas – ponds, landfill, coal storage areas
Non-heterogeneous, non-isotropic and non-horizontal flow conditions
Time variant contaminant loading
A three-dimensional transient ground water flow model was developed for the site using the 1996 version of MODFLOW. The MODFLOW simulation was created using the graphical user interface GMS developed by the Environmental Modeling Research Laboratory of Brigham Young University in partnership with the United States Engineer Waterways Experiment Station. After calibration of the flow model was achieved, a contaminant transport model was constructed using the 1998 version of MT3DMS. The transport model used the flow model information to simulate contaminant species introduced in the flow regime from the surface water ponds. The transport model was advective and dispersive, but no retardation or changes of the plume characteristics due to chemical reactions in the aquifer were simulated.
After calibration to the available historical monitoring data, the model was used to predict future impacts, site and design new ponds, and design a remediation system to pump contaminated ground water back into the settling ponds.
The facility has 5 industrial landfills, over 200 acres of various process water ponds, and a large coal storage area. WET Personnel completed a ground water contamination investigation of the facility to determine the source(s) of ground water impacts at the site.
The investigation included geochemical modeling to identify contaminant fingerprints and a statistical model of the alluvium/bedrock contact. The topography of the bedrock surface controls ground water flow on the site in a paleochannel of the North Platte River. Once the channels were defined, a monitoring system, completely characterizing the site was installed.
Ongoing monitoring of the site has identified areas where waste is in contact with and impacting ground water. Remedial alternatives have been proposed.
