An Environmental Protection Agency official said the federal government will release a report this fall about the extent of toxic metal contaminants at the Iron King Mine and smelter Superfund hazardous waste cleanup sites in Humboldt.
EPA remedial project manager Leah Butler told the Dewey-Humboldt Town Council Tuesday that officials have collected more than 700 water, soil and sediment samples in town and at the sites.
In addition, they have gathered samples from 46 residential properties - eight of which had elevated arsenic levels and four with elevated lead - and Humboldt Elementary School, 2750 S. Corral St.
This past week, EPA officials took another 400 samples to fill data gaps for the report, which will summarize results from the data.
This fall, the EPA will conduct a public meeting to discuss its findings and options for cleanup, which could start in 2011. The EPA also will release a public health risk assessment.
"It's hard to say yet how big or how bad the contamination is because we're still quantifying that," Butler said. "There weren't really any surprises as far as the mine and smelter's waste and ash piles. They have elevated arsenic and lead, which we expected."
In the meantime, the public can read updated test data at the town's library, 2735 S. Corral St., or on the EPA's website at www.epa.gov.
To track contaminants, the EPA installed six groundwater-quality monitoring wells at the defunct mine and smelter. Of the more than 50 private wells sampled, Butler said 40 percent had arsenic above the federal drinking water standard of 10 parts per million.
However, arsenic in the samples was not high enough to suggest the mine's metals are harming water quality directly. Two future groundwater tests and surface water sampling in the Agua Fria River and its gulches during heavy rains may yield more information.
The EPA is operating four air-monitoring stations, including one apiece at the mine, smelter, Humboldt Elementary and a downwind location. Each station has two samplers that measure dust levels every six days on a rotating schedule until July.
This week, Butler and colleague David Cooper visited property owners in Chaparral Gulch. The gulch carries arsenic from the mine and smelter's tailings in stream water through parts of Humboldt on both sides of Highway 69.
Butler said children should not play in the gulch under any circumstances.
Gulch homeowners received an EPA fact sheet, which is available at the library; town hall, 2735 S. Highway 69; and at www.epa.gov that gives an update on the investigation.
Councilman Floyd Wright voiced his concern about the parties responsible for the contamination at the mine and smelter.
Butler said a case developer group at the EPA is developing a comprehensive list of past and current property owners, generators, transporters and disposers of waste dating back to when the mine opened in the early 1900s to the present.
The EPA group will determine whether those companies or individuals remain viable or if there are successor or parent companies that carry some kind of liability.
"They're looking at when most of the waste was created, what companies were and were not a part of that, and how it all plays out," she said. "The current property owners played a role in that, but, of course, they came in late in the game."
Along with health and safety assessments, the EPA is putting together a reuse assessment, which may determine what becomes of the mine and smelter.
"We're going to need a lot of input from your group on the specifics of what could be done," councilman Don Tebbe told Butler.
Town Manager William Emerson said the smelter has a presumed designation as open space while the mine is presumed as medium density residential zoning, although the EPA study could change that.
"The General Plan, which will go before the voters in November, shows those two pieces of property as study areas, even though they are presently zoned for heavy industry," Mayor Earl Goodwin said. "There will be a need for us to clarify as we go along."
More like this story
- D-H committee leaning toward superfund
- EPA outlines cleanup process for Iron King Mine
- EPA to consider cleanup options for Iron King Mine and smelter sites soon
- IRON KING MINE: Experts recommend cleanup to avoid health risks
- Dewey-Humboldt: EPA official asks governor to consider Iron King Mine, smelter as a Superfund site