CHARLESTON, W.Va. -- Federal and state investigators have found problems with a key water spray system at Massey Energy's Upper Big Branch Mine, but are running into opposition from Massey in their effort to fully test the system, officials confirmed Monday.At least four spray devices are missing from the cutting mechanism, or shearer, on the longwall mining machine at the Raleigh County operation where 29 miners died in a huge explosion on April 5, investigators said.Such sprays are intended to keep down levels of coal dust that can contribute to explosions and cause black lung disease, and can also be effective in preventing ignitions from sparks created when cutting bits dig into coal or rocks.State and federal officials want Massey to reinstall water to the longwall machine and fire up the shearer so they can see if there are other problems with the machine's water spray system."We feel it's very important to us," said C.A. Phillips, director of the state Office of Miners Health, Safety and Training. "It's something that is vital to us."Last week, Massey and the U.S. Mine Safety and Health Administration were unable to reach agreement on a plan to test the longwall shear's water system. MSHA cited the company, officials said, and was considering more serious action.Under federal law, MSHA could issue a unilateral order that would allow the agency to essentially take over the mine site. The law also allows MSHA to seek a federal court injunction against an operator that is impeding an investigation."MSHA is attempting to negotiate with Massey to come up with a reasonable solution," said agency spokeswoman Amy Louviere. "We would like to avoid taking legal action. However, if we can't reach a resolution, we will consider using any tools at our disposal that we feel are warranted."Shane Harvey, Massey's general counsel, said his company "has no issue" with testing the shearer, but wants to hold off turning on the water sprays until Massey has completed its internal investigation in that part of the mine."This area includes a floor crack that may have allowed natural gas to inundate the mine," Harvey said through a company public relations agent. Harvey said the MSHA plan could "destroy critical evidence."Reach Ken Ward Jr. at email@example.com or 304-348-1702.