Atlantic Richfield is trying to extract itself from legal and fiscal involvement in the Mike Horse Dam removal.

In documents filed this month in U.S. Bankruptcy Court in Texas, lawyers for Atlantic Richfield n also known by the acronym Arco n say that a three-year federal and two-year state statute of limitations for claims ran out long ago.

In addition, Atlantic Richfield claims that under the Clean Water Act, only the current facility owners and operators can be held liable for natural resource damages.

The lawyers note that Atlantic Richfield "relinquished all property interest and ceased all mineral exploration activities at the site more than 25 years ago."

"... it is undisputed that the state has known about mining-related releases of metals at or from the site and impacts to natural resources since at least 1975, and certainly no later than the mid-1990s," the lawyers write. "Any cause of action ... would have accrued at that time, meaning that the two-year statute of limitations has long since expired on the state's claims."

In addition, Arco's lawyers argue that the bankruptcy court doesn't have jurisdiction in deciding Atlantic Richfield's potential liability to the state regarding natural resource damages.

A spokesman for the company didn't return a call seeking comment on the situation.

The filings are part of the ongoing Asarco Chapter 11 bankruptcy case and the effort to remove the defunct Mike Horse Mine 15 miles east of Lincoln.

Asarco owns the Mike Horse Mine and the mothballed East Helena lead smelter, as well as other properties throughout the nation, and is trying to reorganize and emerge from Chapter 11 bankruptcy, which it filed for in August 2005.

As part of the proceedings, Asarco is trying to ascertain its outstanding debts and environmental liabilities.

One of those liabilities involves the Mike Horse Dam east of Lincoln in the Upper Blackfoot Mining Complex (UBMC). In July, Regional Forester Tom Tidwell announced plans to remove the dam and encapsulate the earthen impoundment, as well as other nearby contaminated mill tailings and materials, at an estimated cost of $26.7 million.

Past efforts have focused on getting Asarco to foot the bulk of the bill, but Atlantic Richfield also has been named as a potentially responsible party by state and federal officials.

Asarco's Mike Horse Mine is slightly southwest of the dam and allegedly contributed to the contamination in and around it. The land on which the Mike Horse Dam sits is part of the Helena National Forest's Lincoln Ranger District.

Arco's alleged involvement is due to the fact that when the original Mike Horse Dam failed in 1975, it was repaired by the Anaconda Mining Co., which was bought by Arco in 1977.

In bankruptcy court documents filed in April, Asarco contends that the harms associated with the Mike Horse tailings dam occurred during the 1975 blow-out of the original dam, and when Arco rebuilt the structure, it did so with the approval of the federal government. That means both Arco and the government have some fiscal responsibility, according to Asarco's lawyers.

In addition, Asarco now says that since it gave up the right to unpatented mining claims in the area, which are to be cleaned up as part of the reclamation activities, the federal government needs to be fiscally responsible for more of the work. Those mining claims are on U.S. Forest Service land.

Originally constructed in 1941, the Mike Horse Dam n also called an impoundment n is poised at the headwaters of the Blackfoot River, made famous in the Norman MacLean novel "A River Runs Through It." When the dam blew out in 1975, the contaminated water and sediments ended up killing all aquatic wildlife in a 10-mile stretch of the Blackfoot River.

The dam was rebuilt using nearby materials that included mine tailings. Two years ago questions arose regarding its stability, and a recent report noted large holes, or "voids" in the structure. The Forest Service reported that the dam was a compromised structure that should be removed from service.

Officials with Asarco have said in the past since the issue of financial liability is part of the bankruptcy litigation, the company cannot comment on issues surrounding the Mike Horse Dam and its impending removal.

It's expected that the removal process will take years to complete, but the Forest Service is beginning the task of rerouting Beartrap Creek, which will allow the pool of water to be drained from behind the Mike Horse dam.

But a spokesman for the Forest Service, Bob Kirkpatrick, recently noted that removing the impoundment and associated contaminated soils hinges on getting through bankruptcy court proceedings and bringing Arco to the table.

www.fs.fed.us/r1/helena/projects/blkfoot_mine.shtml

www.asarco.com

www.arco.com