Readily available labor due to the economic downturn and a more favorable proximity to Western Slope coal mines are among the factors prompting a Denver company to reopen a long-dormant limestone quarry north of Glenwood.



CalX Minerals LLC recently notified the U.S. Bureau of Land Management that it intends to resume mining at the former Mid-Continent Quarry on Transfer Trail sometime this month or next.



The company purchased the mining claims and permit from the Mid-Continent subsidiary Pitkin Iron. Although the quarry has been inactive since the late 1980s or early '90s, it has been in operation off and on since the 1950s, serving Mid-Continent's former Redstone coal mine operations.



As recently as 2006, previously mined material was hauled from the quarry site.



Because the operations will be confined to the roughly 16-acre original permit area, no new permits or authorizations are required, Glenwood Springs BLM Field Manager Steve Bennett said in a press release.



"Mining operations have been authorized by BLM and the state of Colorado on this claim for several decades," Bennett said.



According to Ben Miller of CalX, the quarry had previously been providing limestone to a rock dust plant in Delta. The produce was then sent to coal mines in the region. Rock dust is used in underground mines to help reduce coal dust and prevent explosions.



With the new operation, the limestone will now be processed on site in Glenwood Springs and sent directly to the mines, he said.



"We are hoping to provide rock dust at reduced rates," Miller said. "That is one of the key reasons that the market is available to us."



In addition, "Because this quarry is located relatively near several regional coal mines, we expect truck trips to the coal mines will be reduced by 1.2 million truck miles per year," Miller said in the BLM release. "This would reduce the amount of CO2 emissions by 9.8 million pounds each year."



Limestone is also used for acid mitigation in mine reclamation projects, such as at the Climax mine in Leadville, and it has a number of "green" applications, including cutting down on acid rain-forming emissions from coal-fired power plants, Miller said.



"The Mid-Continent limestone is some of the highest quality limestone in North America," he said.



Miller said he expects the quarry will have between 10 and 20 direct employees, in addition to trucking needs.



"We are setting up contracts with local trucking outfits," he said. "There are a lot of folks out there looking for heavy construction type of work, especially those displaced from the oil and gas industry. Twelve months ago it was tough to get people to operate heavy machinery, but that's changed drastically."



In accordance with the existing permits, operations will consist of quarrying and grinding rock on site. Grinding can occur indoors around the clock, while mining, crushing and screening will be limited to the hours of 7 a.m. to 5 p.m. Monday through Friday.



Some blasting is also allowed to occur between April and December each year, averaging about one blast a month.



Miller said he does not expect the blasting to generate excessive noise or vibrations. Blasts will be closely monitored to ensure vibration control, he said.



CalX anticipates truck traffic to be about 20 round trips each day. Dust abatement, signage and road maintenance are also planned for Transfer Trail, which provides year-round access to the Flat Tops area.



The closest neighbor that stands to be impacted by the resumed quarry operations is the Glenwood Caverns Adventure Park. Miller said he met with owner Steve Beckley, who he said expressed some concerns about dust and possible vibrations from blasting.



Miller said they will work with their blasting contractor to ensure vibrations are kept within acceptable levels.