Colorado state officials meet with officials from the U.S. Forest Service, Bureau of Land Management and U.S. Environmental Protection Agency to develop plans to build a complete, interlinked inventory of the hundreds of inactive mines draining into Colorado waterways, aiming to prioritize the worst of the worst for cleanup.

“Putting it all together is the building block to be able to take the next step, which is a prioritization list,” Colorado’s senior water quality scientist Andrew Ross told The Denver Post. “Then we can put together a state reclamation plan.”

The Colorado Department of Public Health and Environment (CDPHE) estimates that acidic metals-laced mine water contaminates more than 1,600 miles of streams and rivers. There are an estimated 23,000 inactive mines in Colorado — 22,000 on federally managed public land — that companies have abandoned. These are a main source of harm to waterways that affects human health and ecosystems.

While multiple federal and state agencies hold information on inactive mines, there's no comprehensive data hub that could be used to assess impacts, risks and costs for cleanup.

Government officials from the CDPHE, Colorado Geological Survey and Colorado Department of Natural Resources, met with the federal officals at the regional Forest Service headquarters to focus on how best to share data and identify gaps.

CDPHE and the CGS are leading a $300,000 inventory initiative.

“I don't think we really know what the cumulative impacts of all these are,” CGS director Karen Berry said.

Colorado officials also advocate legal changes to encourage voluntary cleanups. So-called "good Samaritan" legislation, introduced in Congress, would let companies and conservation groups launch projects to reduce contamination in streams without being liable, under the Clean Water Act, for remaining contamination, state abandoned mines program director Bruce Stover said.

Such a change would make a difference, Stover said, and volunteer groups wouldn't be held liable if well-intentioned cleanup work causes spills, such as the Aug. 5 Gold Mine incident where a 3-million-gallon torrent turned the Animas River mustard-yellow.

Lawmakers also are considering reform of the nation's 1872 mining law to charge hard-rock mining companies fees to create a fund that could be used to help deal with drainage from inactive mines.

Gov. John Hickenlooper has met with fellow western governors and federal agency chiefs and found that a consensus has emerged to make cleanup of old mines a priority. At least 230 are known to be draining into Colorado waterways with 148 largely unaddressed — not visited since the 1990s.

State officials say natural resources crews aim to visit those sites and test water this year to assess the harm.