Maclean 3 Project - Utah Division of Oil Award Nomination Utah Abandoned Mine Reclamation Program Maclean 3 Project The Maclean fire was a public safety hazard. Spring Canyon attracts

2012 Abandoned Mine Reclamation Awards

NOMINATION

Maclean 3 Project Spring Canyon, Carbon County, Utah

Submitted by:

Abandoned Mine Reclamation Program Luci Malin Utah Division of Oil, Gas & Mining Program Administrator 1594 West North Temple, Suite 1210 801-538-5323 P.O. Box 145801 [email protected] Salt Lake City, Utah 84114-5801 801-538-5340 Project Summary: Construction Start Date: October 17, 2011 Construction Completion Date: May 31, 2012 Construction Cost: $521,105.79

Responsible Organizations -- The Project Team --

Project Management Abandoned Mine Reclamation Program Luci Malin, Program Administrator Utah Division of Oil, Gas & Mining Louis Amodt, Project Manager

Abandoned Mine Reclamation Program Staff: Louis Amodt, Steve Fluke, Tony Gallegos, Connie Jo Garcia, Wayne Hedberg, Luci Malin, Jan Morse, Bob O’Brien, Chris Rohrer, Ken Wyatt

Engineering/Field Management Spectrum Engineering Donald P. Sutton, P.E., President 1413 4th Avenue William C. Maehl, P.E., Vice President Billings, Montana 59101 David Murja, Vice President 406-259-2412 Ted Fitzgerald, P.E., Field Inspector Reclamation Construction Hayward Baker Inc. Todd Ross, Area Manager 4001 South 700 East, Suite 539-540 Salt Lake City, Utah 84107 801-363-0546 Date Submitted: April 13, 2012

Submitted to:

Office of Surface Mining Reclamation and Enforcement 1951 Constitution Avenue NW

Washington, DC 20240

Reclamation Award Nomination Utah Abandoned Mine Reclamation Program Maclean 3 Project

Introduction

Underground coal fires are notoriously stubborn creatures to control. In theory, the approach is the same as controlling any fire—remove one or more of the three components of the classic fire triangle: heat, oxygen, fuel. However, it gets complicated quickly when the fire is underground. How does one extinguish a fire when its location is uncertain, when a vast coal seam provides unlimited fuel, when countless cracks and fissures and mine workings supply oxygen, and hundreds of feet of rock overburden provide heat-trapping insulation? Putting out a coal mine fire is just like putting out a house fire, provided you cannot see or touch the house.

The Maclean 3 Project is the culmination of more than two decades of study, work, more study, and more work trying to put out a coal seam fire at the Maclean mine. The attached chronology summarizes the investigations and trials. After several attempts, the fire finally appears to be out.

Project Description

The Maclean coal mine is located in central Utah, in Carbon County, up Spring Canyon west of the town of Helper. Spring Canyon was one of the historic centers of Utah coal mining. In its prime, there were dozens of mines strung along the seven mile trunk of the canyon. Company towns with tidy rows of cottages and stores filled the canyon. Towns like Liberty, Rains, Mutual, and Standardville supported several thousand people for the first half of the twentieth century, until the production waned and the people gradually relocated to other coal camps in the county, sometimes taking their homes with them, but more often leaving the tipples, tramways, offices, stores, and houses behind as relics to decay over the years amidst the sagebrush and junipers.

The Maclean mine started operating around 1919. The underground mine fire at the Maclean mine started in the 1940s and resulted in the closure and abandonment of the mine in 1945. When the Utah Abandoned Mine Reclamation Program (AMRP) came on the scene in the 1980s, the underground fire was still burning. The fire was expressed on the surface as fissures and crevices venting hot fumes and smoke. As the fire burned away the coal over the years, it created underground voids that collapsed and brought down the overlying rock and soil. A full acre of hillside in the fire zone had slumped. A grove of mature conifer trees had been killed and native vegetation over several acres had been replaced by weedy annuals due to the heat stress and fumes.

As investigations progressed, it became clear that there were multiple fires in multiple coal seams. Fires underlay about fifteen acres. By 2010, long surface cracks 12-15 inches wide were apparent on the ridgeline 170 feet above the mine as the fire migrated to unmined rider seams stratigraphically above the mined seams. Steam and fumes rose from the ground as a bulldozer built a road to the area and prepared a drill pad, causing the project engineer to abandon that borehole location out of concern for the safety of the crew.


The Maclean fire was a public safety hazard. Spring Canyon attracts ghost town buffs and is a popular deer hunting locale. There are two residences nearby. A network of old mine roads and newer ATV trails permeates the canyon making all parts accessible. The ground surface above the fire is prone to caving underfoot; some crevices were large enough to swallow a person (or livestock or wildlife). Air quality was compromised. Vegetation was damaged, with lost timber and diminished range quality. The underground fire carried the risk of igniting surface vegetation and starting a range or forest fire.

The AMRP reclaimed most of the Spring Canyon mines in the mid-1980s. The projects sealed over a hundred mine portals and buried dozens of coal refuse piles totaling over 200,000 cubic yards. While some conventional reclamation (coal refuse burial, structure demolition) was done at the Maclean mine at that time, the fire presented a unique set of problems and was reserved for a dedicated project.

Difficulty

Extinguishing the Maclean fire required facing and overcoming several challenges. One of the biggest was the basic and fundamental task of understanding the nature and behavior of the fire when the burn zone was hidden behind hundreds of feet of rock. The exact location and size of the fire were unknown. Surface expression of the fire was an unreliable tool—vents could be far removed from the actual fire front as fumes could travel through a system of fissures to reach the surface. Understanding the fire required several programs of drilling to be able to sample gases and measure temperatures underground. Then the gas and temperature data had to be interpreted. Inferences about the intensity of the burning could be made from the temperatures and ratios of gases in each sample. The borehole data had to be modeled in three dimensions, overlain with geologic and mine workings maps, and tracked over time to see the effects of the various treatments (it turned out that the fire was a bit like a Whack-a-Mole game— treating one area would have a local effect, but new burning would pop up somewhere else). It took sophisticated analytical capabilities to visualize the fire and design drilling plans that would deliver suppressant and grout to the desired locations.

There were logistical challenges for construction as well. Spring Canyon has steep walls and many cliffs; slopes at the Maclean mine are 60-90%. The fire affected an area spanning a vertical range of 400 feet. There was an old existing road to the original mine portals, but new roads had to be cut to access the fire area. Work pads were tightly constrained by the terrain. Surface soil seals are a common treatment for mine fires; the soil seal placed at the Maclean mine had to be contained in gabion mattresses and anchored with roof bolts to keep it in place on the steep slope.

Managing the construction was no easy feat for the contractor or the supervising project engineers. It was a complicated job. There were many pieces of equipment mobilized onsite by the prime and subcontractors, including dozers, trackhoes, loaders,

Reclamation Award Nomination Utah Abandoned Mine Reclamation Program Maclean 3 Project drill rigs, dump trucks, forklifts, storage tanks for fluids, compressors, a foam truck, and grout mixing and pumping equipment. All had to negotiate narrow roads and cramped work areas. Work materials (grout, surfactant, drilling fluids, casing, sand, etc.) had to be delivered to the right location at the right time. Boreholes had to be logged and the data analyzed. Most of the work was done in the late fall and winter with subfreezing temperatures and snow cover.

Effectiveness

The Maclean fire is out.

Since the work at the Maclean mine began twenty years ago, Spring Canyon has undergone a small renaissance. In recent years two new residences have been built within half a mile of the mine. The local community has paved a walking/jogging/biking trail up the canyon, mostly following the old mining railroad grade, bringing more and more people back to the area for recreation. None of this was expected or predictable in 1988 when study of the Maclean fire began, but it underscores the value of the work. Sometimes external events catch up with you. Public use of the canyon grew as the fire study occurred. The early start on the fire control enabled the fire to be extinguished in time for unanticipated growth that otherwise would have increased the hazard posed by an active fire.

The U.S. Bureau of Mines had tried to extinguish several coal seam fires in similar terrain in Utah in the 1960s using surface soil seals. They bulldozed a lot of ground but failed to put out the fires. The drilling techniques used at the Maclean fire allow quenching and sealing to be done with minimal surface disturbance and with a higher probability of success.

Funding/Partnerships

The Maclean 3 Project construction was completed for $521,105.79. All funds were from OSM grants from the SMCRA AML Fund.

The Utah AMRP partnered with its counterparts in the Colorado Inactive and Abandoned Mine Land Program to exchange ideas and share experience with coal fires. This interaction spread the value of the SMCRA funds expended in each state.

The FEM-12 fire suppressant product tested in 2002 was developed by George

Uhlig, a professor at the nearby College of Eastern Utah (CEU) in Price, Utah. Dr. Uhlig developed FEM-12 for surface fires, but the Maclean fire offered an opportunity to try it in a new application. Both the AMRP and CEU benefitted from this collaboration. At the conclusion of the 2002 project phase a small surplus of FEM-12 material was donated to the Price City Fire Department, where it will be very effective at fighting fires.

Benefits


Utah has about a dozen underground coal mine fires and a dozen more outcrop fires. Most of them share characteristics with the Maclean fire, such as locations in steep canyons with difficult terrain (steep slopes, boulder colluvium, cliffs) and slope failures that provide multiple conduits for oxygen. The Maclean mine’s location near the town of Helper made it the most hazardous to the public, and thus a priority to extinguish. It also made it a good candidate for study. Its convenient location made it ideal for demonstration projects to test fire control techniques. The coal seam at the mine was isolated by faults from the rest of the coal field, so long term studies could be conducted without risk of the fire spreading great distances and threatening the entire reserve.

The various phases of the Maclean work tested several traditional and innovative fire control technologies: surface seals, colloidal concrete, FEM-12 suppressant, cellular grout. They honed analytical capabilities that made it possible to model the fire using remote techniques. The intensive drilling program carried out in 2011 allowed engineers to locate the burning coal seams, locate faults that separate seams, and make inferences about the subsurface geology and fire behavior. In turn, this allowed for prediction of where the pumped grout and fire suppressant would go once it was placed underground.

The AMRP has identified the Horse Canyon mine fire in eastern Carbon County as its next fire control project. The Horse Canyon fire has been burning since 1976 and is situated in even more rugged terrain than Maclean. The lessons learned at the Maclean mine are directly applicable to the Horse Canyon fire. Armed with new techniques and experience, it is safe to expect that the Horse Canyon fire can be controlled in a shorter time and at less expense than the Maclean fire. The same lessons are also transferable to similar fires outside of Utah.

The larger benefit, of course, is improved public safety. The Maclean fire emitted carbon monoxide and hydrogen sulfide gases in lethal concentrations. People can now visit the area without the risk of falling down a crevice and getting burned or asphyxiated. Livestock and wildlife are similarly protected. Ambient air quality is improved. These benefits are especially important to the two homeowners in the project vicinity, but also to all the recreating public the area attracts.

SMCRA

The Maclean 3 Project and its predecessors are excellent examples of SMCRA at work. The problem itself, a coal mine fire, is unique to the SMCRA milieu: no other institution provides a means for dealing with them. Coal fires are clear public safety and environmental hazards that resist easy solutions. The Maclean 3 Project fulfills the SMCRA mission by successfully eliminating a definitive abandoned coal mine problem. No other funding mechanism could have made the project possible.

The project readily garnered media coverage because of the unusual nature of the problem (“60-year-old fire” in a media release will grab any assignment desk’s attention).

Reclamation Award Nomination Utah Abandoned Mine Reclamation Program Maclean 3 Project Several television and newspaper reports covered the project. The news stories raised public awareness of abandoned mine problems and the efforts through SMCRA to solve them. Now that the fire is out, there is another positive story to report.


Maclean Mine Fire Reclamation Chronology

1988 The Standardville Project reclaims environmental disturbance at the lower part of the Maclean mine site near the canyon floor. Structures were demolished and coal refuse buried. A segment of stream channel was rehabilitated. The fire is not addressed. Engineering/design: Dames & Moore Inc.; Construction: Ned B. Mitchell Inc.

1988-1989 The AMRP hires the consulting engineering firm Goodson & Associates to study the Maclean fire and develop a strategy to control it.

1990 The Maclean 1 Project makes the first attempt to control the fire by sealing off pathways for oxygen to the coal seam. The project sealed 13 portals, improved the access road, and created a work pad that would stage activities for the next twenty years. Large fissures in the landslide zone were filled by pumping in low density colloidal concrete (“foaming mud cement”), 2300 cubic yards in all. Engineering/design: Goodson & Associates and Delta Engineering; Construction: Gerber Concrete Construction Inc. and Colloidal Concrete Corp.

1992 The Maclean 2 Project makes the second attempt to control the fire by sealing off oxygen pathways. This time the entire landslide area was blanketed with a one-acre mat of wire baskets (gabion mattresses) laced together as a unit, filled with soil, and anchored to the steep slope with long steel bolts. A chimney installed over the primary vent fissure carried smoke up above ground level. Engineering/design: EarthFax Engineering; Construction: Gerber Concrete Construction Inc.

2002 The AMRP tries a pilot study of a fire suppressant chemical that lab tests had shown to rapidly quench fires and reduce temperatures. The AMRP drilled 24 holes into the burning coal seam and injected 7,000 gallons of a water-based fire suppressant (FEM-12) into five of the hottest holes. Thermocouples were installed in eleven holes to allow monitoring of temperatures at depth. The AMRP conducts monthly temperature monitoring and periodic gas sampling from October 2002 to September 2009. Engineering/design: The Opal Group, LLC; Construction: Hayward Baker

2004-2005 The AMRP improves site access and drills seven more holes equipped with thermocouples and gas sampling ports. Monthly temperature measurements and gas sampling continue. Engineering/design: AMRP in-house; Construction: Hayward Baker

2010 The Maclean 3 Project continues to analyze the fire with the addition of seven more monitoring holes. Large cracks in the main fire area are filled with cellular grout. A separate fire zone in rider seams above the mined out Castle Gate seams is identified. Engineering/design: Spectrum Engineering; Construction: Hayward Baker

2011 The Maclean 3 Project analysis continues with ten more monitoring holes bored in January-February. In the fall, the Maclean 3 Project attempts to extinguish the fire by cutting off the oxygen supply. Additional holes are drilled and grout is pumped into subsurface voids and fissures. Engineering/design: Spectrum Engineering; Construction: Axis Drilling and Hayward Baker

2012 Inspection of the Maclean mine with a thermal infrared camera in February shows surface temperatures in the fire zones to be equal to ambient. This corroborates borehole temperature data. The AMRP declares the fire dead. Access road removal and reseeding performed in the spring wrapped up the project.


2012 Abandoned Mine Reclamation Awards

NOMINATION

Maclean 3 Project Spring Canyon, Carbon County, Utah

Crew pumps grout into a borehole to cut off oxygen supply to the fire.

Submitted by: Abandoned Mine Reclamation Program Luci Malin Utah Division of Oil, Gas & Mining Program Administrator 1594 West North Temple, Suite 1210 801-538-5323 P.O. Box 145801 [email protected] Salt Lake City, Utah 84114-5801 801-538-5340


Smoke and fumes billow from subsidence crevices (left) and new boreholes (right) at the Maclean fire in 2002. Note the trees in the background killed by the fire. This is the same area shown in the cover photo.

Slope above the Maclean mine. Snowmelt is visible evidence of ground heating from the fire below the surface. The plant stalks at the right foreground are mullein, a weedy plant that invades disturbed areas, further evidence of environmental stress on vegetation.


Gaping fissure created by rotational slope failure due to fire-induced subsidence. Fissures such as this vented fumes from the underground fires.


Annotated aerial photo showing the Maclean mine fires in relation to the landscape and geologic features. Understanding the fire required precise mapping of features and detailed interpretation of the geologic structure. The project engineers compiled information from historic mine workings maps, field observations of surface geology, drill logs, infrared photography, and subsurface observations from borehole temperature and gas measurements.


Left: Borehole thermocouple temperature readings show temperature declines after the FEM-12 injections in 2002. Below: 3-D representation of borehole temperature data.

In order to put the fire out, the AMRP first had to figure out where it was and what it was doing. An array of cased monitoring boreholes with thermocouples and gas sampling ports generated loads of field data. Back at the office, modeling the fire tapped all available analytical capabilities to manage data in three spatial dimensions plus changes over time.

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Coal dust flies as a drill strikes a coal seam in preparation for grout injection.

Pouring cellular grout into a subsidence crevice in 2010. Grout injected into boreholes and crevices cut the air supply to the fire.


Visible and infrared photos of one area of fire expression. February 2012. Cooling surface temperatures indicate that the fire is finally out.

Documents

Maclean 3 Project - Utah Division of Oil Award Nomination Utah Abandoned Mine Reclamation Program Maclean 3 Project The Maclean fire was a public safety hazard. Spring Canyon attracts