Client: Cement Company
Location: Albany County, Wyoming
Project Overview: Trihydro was contracted by a cement company to revise the mine permit for a series of limestone quarries located in Albany County, Wyoming. The requested revisions included accounting for an increased area of disturbance and preparing updated mining and reclamation plans. Specific elements of the project included:

• Incorporation of two existing quarry sites into a single mine unit in order to facilitate continuous mining and reclamation sequencing
• Storm water modeling and design of surface water/sediment control structures
• Hydrologic analyses to evaluate pre- and post-mining conditions, catchment areas, discharge rates, and reclaimed channel hydraulic design/morphology
• Update of mine plans to reflect revised areas of disturbance, current overburden stockpiles, topsoil stockpiles, extracted commodity, haul roads, and permit boundaries
• Design of post-mining topography, topsoil/overburden distribution, and revegetation plans
• Development of reclamation bond release criteria based upon comparison area methods
• Regulatory agency meetings and coordination in order to facilitate submittal and approval of permit revisions

Client: Wyoming Abandoned Mine Lands Division
Location: Central Wyoming
Project Overview: Trihydro has been involved with an underground coal mine reclamation (UCG) project at a remote location in central Wyoming since 1995. The site was operated under a research and development license approved by the Wyoming Department of Environmental Quality (WDEQ)/Land Quality Division (LQD) to test the feasibility of applying UCG technology in steeply dipping coal beds of the eastern Great Divide structural basin. Feasibility testing of UCG technology at the site was conducted during April and May 1995 and from September through December 1995. All active UCG operations were terminated in December 1995, and site reclamation commenced in January 1996.

A total of one production well, six injection wells, and thirty-three monitoring wells were constructed at the site during active UCG operations. The remaining wells are being used for groundwater reclamation at the site. A NPDES permit with WDEQ/Water Quality Division (WQD) has been obtained to regulate discharge of extracted groundwater and facilitate remediation and monitoring at this remote location.

Considerable water quality and hydrogeologic testing were completed to characterize subsurface conditions (greater than 1,500 feet), as well as the nature, degree, and extent of impacts. Hydraulic fracturing was completed to facilitate remediation. Extraction, treatment, and bioremediation are planned at the site to aid groundwater restoration, pending WDEQ approvals. Extracted groundwater will be treated for reintroduction back into the formation in order to aid microbial degradation of remnant hydrocarbon compounds. Nutrients and dissolved oxygen levels will also be monitored as part of the recirculation process to optimize bioremediation activities.

The former UCG site is also in active surface reclamation, including: restoration of ground surface topography, re-seeding, and erosion control measures. Soil samples were collected and analyzed to identify possible contaminated areas prior to reclamation or continued use of these areas. Post-mining contours were restored at the site under the Phase 1 surface reclamation plan. A total of 42.3 acres of topsoil disturbance have occurred at the site. Of these, all but approximately 19.1 acres have been regraded, revegetated, and reclaimed.

Subsidence monitoring was conducted on a quarterly basis for approximately 2.5 years, and the monitoring is now conducted every two years (biannually). Surface water monitoring has been limited to mapping and comparing dry fluvial channel morphology in an unnamed drainage located in the northern portion of the site. The semi-arid climate and rugged relief of the area has resulted in no perennial surface water within two miles of the mine site. Surface water flow has not been observed while field personnel are on site.

Client: Wyoming Abandoned Mine Lands Division
Location: Statewide, Wyoming
Project Overview: Trihydro was retained as a specialty sub-consultant to create a Geographic Information System (GIS) application for the State of Wyoming Department of Environmental Quality (WDEQ)/ Abandoned Mine Lands Division (AML). The GIS serves as a user interface to the custom MS Access database created as part of the AML 8.1 Ongoing Inventory Project. Built in an ArcView GIS software environment, the GIS application provides users with an “always up to date” depiction of the status of AML sites, a user friendly query system, a single interface for all digital data, relevant site background information, and a structure under which future AML site-specific data and drawings can be housed.

Trihydro was also charged with creating a user-friendly query interface for the GIS layers and the Access database. Using custom ArcView dialogs and queries, a menuing system was created that allows AML personnel to query sites based on site number, legal description, county, HUC, AML status, land ownership, project number, and other site-specific information. The query tool was tailored to meet future AML needs in a simple and user-friendly manner, and structured so that unforeseen queries could also utilized. As the user identifies the AML site of interest and zooms to a more local scale, additional GIS layers are added to the project automatically. These additional layers include digital USGS quadrangles, detailed roads, elevation layers, and aerial photography.

In addition, custom programming was added to the project to allow the “linking” of other types of non-GIS data to the individual sites. GPS files, photos, scanned field notes, CAD construction drawings, and other digital files can now be accessed easily by the user once the site of interest has been identified through the query process. AML personnel are able to add new files (photos, GPS, etc.) to the specific site directory and immediately have information accessible within the GIS. This allows for the tracking of progress on individual site remediation projects and seamless combination of information from multiple contractors. Future plans for the project call for AML field offices to be updated quarterly with database modifications and ongoing inventory results.