A local health official said all of the yards in East Helena known to contain more than 1,000 parts per million of lead could be cleaned up within the next four years, ending more than a decade of soil removal and replacement.

The new plan, which was announced on Wednesday, calls for at least 30 residential yards in East Helena to be replaced this summer, with the work funded by $450,000 from Asarco. That's up from about 10 residential lots that were being remediated annually during recent years.

Joan Bowsher with the Lewis and Clark City/County Health Department's environmental division said she hopes that the remaining 155 known residential properties in need of cleanup could be completed by the end of 2008.

"We're hoping 30 can get done this year, 50 to 60 the next year, the remainder the following year and leave one more year just in case work isn't completed," Bowsher said.

The cleanup cost per yard ranges widely based upon the size of the lot and the complexity of the work, but can run anywhere from around $10,000 to $50,000.

One of the significant changes in the plan, which will allow for more work to be done each year, is that remediation will be done on all lots with lead levels higher than 1,000 parts per million, instead of just those where pregnant women or young children live and have high lead levels.

Chris Pfahl, closed plant site manager for Asarco, said that eliminating the need to focus on high-risk properties this year allows work to be done on more lots.

"Our goal has been to get this thing done, and it's been dragging for too long," Pfahl said. "The reality is if we just did the high-risk yards, this could go on forever. Since funding was available, we decided to accelerate the work."

Pfahl said that as far as he knows, this is only a one-year modification to the existing Administrative Order on Consent which governs the cleanup in East Helena, but he added that Asarco is willing to consider similar changes in future years based on available funding.

Lead occurs naturally in soil in the Helena area at about 80 parts per million. But it also was emitted through Asarco's smokestacks as part of the smelting process during the past 100 years.

Asarco "temporarily closed" the smelter in 2001, but one study in 1983 showed that when it was operating, 7.1 tons of lead fell onto the East Helena area in a given year, or about 1,200 pounds per month.

That lead caused concern, mainly because of the impact to children whose growing bodies and minds are more sensitive to lead poisoning. Lead in children can cause hearing loss and slowed growth, can reduce IQ, and induce hyperactivity. At high levels, it can cause coma, convulsions and death.

The soil cleanup activity began in 1991, seven years after East Helena was designated an EPA Superfund site due to Asarco's pollution. Since then, the company has spent more than $13 million on soil remediation efforts, and cleaned up more than 700 yards.

Four years ago, EPA officials were reconsidering the 1,000 ppm figure that triggered cleanup, noting that under the federal Toxic Substances Control Act (TSCA), cleanup elsewhere can kick in at 400 ppm.

In 2001, Scott Brown, the East Helena Superfund site manager, said there was some question as to whether TSCA applies to Superfund sites, but that the agency was considering reducing the action level for cleanup in East Helena.

Bob Fox, Superfund branch chief based in Helena, said on Wednesday that they're still working on a final decision for the action level in East Helena.

"We are pushing forward, trying to get to a final cleanup decision," Fox said. "In the meantime, we'll continue under the current agreement."

An official with the Department of Environmental said that while they'd like to see the action level lower than 1,000 ppm, the state agency is pleased that the remediation work is moving forward.

"We have argued for a number less than 1,000 but higher than 400, and is still something we're discussing internally," said Kevin Kirley, DEQ federal Superfund section supervisor. "I think the work that's being done is fine and we are generally satisfied with it, but we still haven't worked out the final action levels and ultimate remedy requirements."

Reporter Eve Byron can be reached at 447-4076 or eve.byron@helenair.com.