Eight U.S. mine operators were put on notice recently for a "potential pattern of violations" - a show by the Mine Safety and Health Administration that it intends to step up enforcement in the wake of the 2006 Sago mine disaster.

None of the eight mines are in Wyoming, where some 6,000 mine employees and contractors work in coal, trona, bentonite and gravel mines.

The eight operators face special sanctions if they fail to improve compliance with MSHA safety regulations.

"If they don't meet the criteria, then we can issue withdraw orders at any time," MSHA spokeswoman Amy Louviere told the Star-Tribune. "That means shutting down a portion of the mine, and that effects production. That's one of the strongest steps we can take to enforce this process."

Mine operators placed under notice include coal mines in Kentucky, West Virginia and Alabama, an iron ore mine in Michigan and a cement mine in California, according to MSHA. They were found to be in violation of health or safety standards under section 104(e) of the Federal Mine Safety and Health Act of 1977.

Since the Sago mine disaster in 2006, congress has pressured MSHA to step enforcement of existing health and safety standards as well as adding new measures. Much of the Mine Improvement and New Emergency Response (MINER) Act of 2006 was aimed at emergency response in underground mining. But sweeping reform of the nation's mining safety laws are expected to effect surface mining as well.

This week, Democrats introduced legislation in the U.S. House that would build on the MINER Act by increasing penalties for patterns of safety violations, provide protection to mine employees who report unsafe conditions and further limit coal dust.

But the National Mining Association said the supplemental bill may go too far. The industry group issued this statement on Tuesday:

"Safety is not well served by imposing additional, overly burdensome requirements such as those proposed in the legislation introduced today until the many new safety requirements of the MINER Act have been fully implemented and their effectiveness properly assessed."

Marion Loomis, executive director of the Wyoming Mining Association, said his organization isn't lobbying for any changes in the federal legislation currently. The association is holding its annual convention this week in Sheridan where safety is a main focus.

"The industry is continuing to make every effort to have zero accidents," Loomis said on Wednesday. "We talked in board meeting today about how we need to do everything we can to address safety at the mine sites."

Although none of the eight mine operators placed under special notice this week are in Wyoming, MSHA has taken similar action against a Wyoming mine.

Last summer, Arch Coal Inc.'s Black Thunder mine was placed under order by MSHA to close a section of the mine on July 31, then again ordered to close another section of the mine on August 22 due to dangerous highwall conditions which put its employees in "imminent danger," according to MSHA.

No accidents or injuries were associated with the 2006 incidents, according to MSHA and Arch Coal officials. Both closure orders were lifted after repairs were made to the highwalls.

Energy reporter Dustin Bleizeffer can be reached at (307) 577-6069 or dustin.bleizeffer@casperstartribune.net.