CHARLESTON, W.Va. -- The Obama administration is sending a multi-agency team to West Virginia this week as public concerns mount about the state's handling of last month's chemical leak that contaminated drinking water supplies serving 300,000 residents.Officials from the U.S. Environmental Protection Agency and the Centers for Disease Control and Prevention will be in Charleston on Wednesday at the request of Gov. Earl Ray Tomblin.The governor asked for additional federal assistance as residents express continued concerns about the safety of their water and about the lack of clear information from state public health officials."CDC has a long pattern of going where we're invited to help on health issues," said CDC spokeswoman Barbara Reynolds. "We've been invited, and we're going."EPA officials did not immediately comment on the trip.Both the CDC and the EPA have had staff members in West Virginia for various periods of time since the Jan. 9 leak.EPA officials have been involved most directly in activities at the site of the Freedom Industries leak, while CDC officials who visited West Virginia were helping with a follow-up study of the more than 500 residents who sought medical treatment. CDC officials also devised the controversial 1-part-per-million "screening level" the state has used in telling residents that their drinking water is safe.Both federal agencies have at times dodged questions from the media, and neither has appeared publicly to answer questions about the leak, its aftermath or the potential health effects.On Tuesday, the EPA and the CDC both began making staff available for brief interviews.In recent days, state officials have tried to focus attention on the federal agencies, though clear information from various state agencies has also been difficult for the media and the public to obtain.Details of the visit have yet to be fully disclosed, but the CDC indicated that in addition to meeting with state officials there has been discussion of some sort of public or media event.Amy Goodwin, communications director for Tomblin, said the federal agencies would join state officials to "provide an update -- in detail -- on what we have accomplished, where we stand now, and what actions we are taking as we move forward." Goodwin said that update would take place during an afternoon news conference.Also unclear, though, is whether the new EPA/CDC visit will push state officials to do what they've so far been unwilling to do: begin testing of at least some sort of sample of home plumbing systems to determine if MCHM remains inside pipes and water tanks.During a U.S. Senate committee hearing Tuesday, Natural Resources Defense Council senior official Erik Olson noted that testing so far has been done only at the water treatment plant, some public locations such as schools and at fire hydrants.Olson noted that University of South Alabama researcher Andrew Whelton has encouraged state officials also to test inside homes."Even if homeowners have now flushed the water in their homes as recommended, some worry that the chemicals may have penetrated into their plastic water piping during the days that the water was stagnant, and that chemicals may continue to be released into the water for some time," Olson told lawmakers.Olson noted that Whelton's team recently received a grant from the National Science Foundation to work on the issue, but that the grant provides "insufficient resources to conduct an extensive testing regime that would be representative of the 300,000 customers affected."Reach Ken Ward Jr. at email@example.com or 304-348-1702.