MORGANTOWN, W.Va. -- A U.S. Department of Labor report says efforts to reduce the massive backlog of contested mine safety violations across the country have been relatively successful, but new ones continue to pour in.A report to Congress last week says the number of current cases at the end of July was about 17,100 -- about 500 fewer than the same month the previous year. That's despite a flood of more than 11,000 new appeals.In July 2010, Congress approved an emergency $23 million to the Labor Department and the federal Mine Safety and Health Review Commission for the project.The project targeted a backlog of more than 10,400 cases and more than 64,000 individual citations issued against operators between Oct. 1, 2007, and Feb. 28, 2010. The Labor Department hired 89 temporary employees, mostly lawyers, and opened new offices in five cities.Ultimately, they resolved about two-thirds of the targeted cases and thousands of others.MSHA spokeswoman Amy Louviere said Tuesday that while supplemental funding for the one-year initiative has run out, lawmakers have provided enough money to continue the project into December. All of Congress' continuing resolutions for spending in fiscal 2012 also ensure the funding continues, she said.Critics of the current regulatory system say mine operators have tried to avoid or delay scrutiny by using their ability to contest violations cited by the federal Mine Safety and Health Administration.Tying the cases up has sometimes hindered MSHA's ability to act quickly at problem mines such as Massey Energy's Upper Big Branch, where 29 men died in an explosion last year despite a long history of violations. The mine is now owned by Virginia-based Alpha Natural Resources.Whether the short-term backlog reduction makes a long-term difference, however, is unclear.In posting the report online Monday, the senior Democrat on the U.S. House Committee on Education noted that operators continue to appeal "nearly every penalty regardless of merit."Since July 2010, the number of cases challenging MSHA citations and fines has risen by nearly 1,600.The agency has tried to eliminate what U.S. Rep. George Miller, D-Calif., calls "incentives" to contest the violations by moving to designate some operators as pattern violators."However, progress in keeping the backlog from growing is in jeopardy," Miller said, "unless additional funds are provided to the Federal Mine Safety and Health Review Commission for judges to hear the appeals and the Department of Labor for attorneys to prosecute these cases."In October, MSHA chief Joe Main told The Associated Press he's still evaluating a pilot program aimed at eliminating the backlog through conference settlements. Two test cases have been reviewed, he said, but the process was labor-intensive, and the agency may not have enough people to handle all the necessary discussions.