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National Information
Regional Information
Site Information
Site Description
Site Risk
Cleanup Progress
Community Involvement
Site Documents
Contacts

National Priorities List (NPL) History
Proposed Date
September 1983

Final Date
September 21, 1984

Superfund Program

East Helena


EPA ID#: COD ID# MTD006230346
Site Type: Active NPL
City: East Helena
County: Lewis and Clark County

Site Description

The East Helena Superfund site includes a lead smelter that operated from 1888 until 2001, the town of East Helena, several residential subdivisions, and surrounding rural agricultural lands. For more than 100 years, lead and zinc smelting operations deposited lead, arsenic, copper, zinc, cadmium, and some 15 other hazardous substances into the soil, surface water and ground water of the Helena Valley. ASARCO shut the plant down on April 4, 2001. The shut down has been characterized by ASARCO as temporary. Public access to the smelter is restricted .

About 1,800 to 2,000 people live within one and one half miles of the smelter complex and most of the residential properties within that area were, until a yard cleanup began in 1991, contaminated with lead above health-based concentrations. Approximately 180-200 residential yards and several hundred acres of undeveloped lands remain contaminated with lead to this day. Most of the area's residences are hooked up to a municipal or community water supply system.

Asarco, the principal potentially responsible party, has cooperated with the Environmental Protection Agency (EPA) in cleanups both on the plant site and in the adjoining community of East Helena.

Site Risk

The soils, surface water, and ground water in and around the smelter are contaminated with lead, other heavy metals and arsenic. Lead is the contaminant of primary concern in soils. Arsenic is the contaminant of primary concern in ground water. Contaminated ground water does not pose a threat because it is not used for domestic water supply and there is no direct human contact. EPA's RCRA program recently found evidence of arsenic contamination at extremely high concentrations in the intermediate zone of the aquifer underlying East Helena.

The site was proposed for addition to EPA's Superfund National Priorities List in September 1983; listing became final one year later.

In 1984, EPA and ASARCO entered into an agreement, in which the company performed a preliminary investigation into site contamination. EPA, the State and ASARCO signed an agreement in 1988 to conduct additional investigations. In 1991, EPA and ASARCO signed a third agreement for the residential soils removal action.

Health advisories were issued in 1988 to area residents advising caution regarding disturbances of soil, dust in houses and their attics, and unwashed home-grown garden vegetables. Advisories also were issued concerning Wilson Irrigation Ditch, which was contaminated and passes through a number of yards and play fields. The ditch was cleaned up in1993 and no longer poses risks.

 

Media Affected Contaminants Source of Contamination
Ground water, sediment, surface water, soils Lead, heavy metals and arsenic Metals smelting and refining

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Cleanup Progress

In late 1989, EPA selected the remedy to reduce ground water pollution from the process ponds at the site. The process ponds were a source of inorganic contamination of soils and ground water. The remedy included isolating the process waters from the ground water by constructing steel storage tanks and replacing leaking equipment. The soils and pond sediments, contaminated by decades of seepage, were dug up and a stored in an on-site landfill. Contaminated process water was treated by on-site co-precipitation technology. The remedy was completed in the fall of 1996, although disposal of cleanup residues became a RCRA concern.

EPA has completed two five-year reviews of site cleanup actions conducted under Superfund authorities. The residential soil cleanup is deemed protective. Although 160-170 properties are still eligible for a cleanup, no children reside at these properties. All properties with resident children were cleaned up first. After 1996-1997, if new families with children became owners or residents of otherwise eligible properties, then those properties were immediately placed at the top of the list for cleanup. The process ponds cleanup, which was conducted while the smelter was still operating and with intentions of preventing further migration of contaminated ground water away from the smelter site, is not deemed protective of the environment. Although there is no human contact with the contaminated ground water, recent monitoring of wells demonstrates that the shallow--and possibly the intermediate--aquifer extending northwesterly away from the plant site, beneath East Helena, remains high in total arsenic. Additionally, recent surface water monitoring of Lower Lake demonstrates that both the water and bottom sediments are still high in metals and arsenic, despite the $3.5 million spent in the early 1990s specifically for a cleanup of Lower Lake.

In July 1991, ASARCO began a non-time critical removal action to remove contaminated soils from residential areas, parks, playgrounds, streets and alleys. ASARCO conducted the majority of the cleanup from 1991 to 1996. The first five-year review also examined and ultimately determined that the removal action is protective of human health. The Record of Decision for the residential soils operable unit is expected to be issued in 2006, following a proposed plan.

Regular ground-water sampling revealed arsenic contamination well above drinking water standards in shallow monitoring wells. ASARCO has drilled additional ground-water wells to define the contamination. Any cleanup will likely occur as part of RCRA program activities.

EPA believes that the residential soils and Wilson Irrigation Ditch removal actions were necessary. These removal actions eliminated immediate sources of soil contamination. Community blood lead levels are now below the threshold of concern. Isolated cases, when they occur, are examined on an individual basis by Lewis and Clark County Health Department professionals, and are generally found to no longer be associated with yard soils.

RESOURCE CONSERVATION AND RECOVERY ACT (RCRA) PROGRAM

The East Helena smelter continued to operate until April, 2001 and is regulated under RCRA. In January 1998, ASARCO and EPA agreed to a multi-million dollar settlement for alleged violations of RCRA and the Clean Water Act. The settlement also specifies a Supplemental Environmental Program and an Environmental Management System for the smelter operation. RCRA will be the governing authority for corrective actions related to the former plant site and ground water. Superfund will continue to be the governing authority for cleanup of residential and agricultural soils, as well as any surface water or surface water source that may require cleanup.

 

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Community Involvement

Currently, ASARCO is funding a county-administered health education and abatement program, with health professionals stationed within the community and its schools. In spring 1999, EPA, ATSDR, the county, DEQ, and ASARCO reviewed the program's effectiveness using door to door surveys and other evaluation methods. A final report is available from the county health department. The program received high grades for its performance.

Since the program's inception in 1995, 1400 individual lead-in-blood tests have been conducted. Fewer than 3% of the children tested during this period exhibited blood lead ratios greater than 10 micrograms per deciliter, and, since 1999, there has been a significant decrease in the numbers of children above the detection limit of 1 microgram per deciliter lead in blood. Of 39 children tested during the first quarter of 2003, no child was greater than 4 micrograms per deciliter, and only one child was above the detection limit. Of 502 children tested from 2000-2004, 97 percent were at 4 micrograms per deciliter or below. Yet, prior to 1985, two-thirds of East Helena's children exhibited blood lead ratios greater than 10 micrograms per deciliter and one-third exhibited ratios greater than 15 micrograms per deciliter.

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Documents

Note: the documents below are PDF files
about PDF files

Site documents from May 1987

Note: the documents below are VERY LARGE PDF files. The best way to open them is to right-click, select "Save Target As" and save to a folder.

Contacts

EPA

Scott Brown
Remedial Project Manager
Region 8, Montana Office
Federal Building
10 West 15th Street, Suite 3200
Helena, Montana 59626
(406) 457-5035
brown.scott@epa.gov

Montana Department of Environmental Quality

Daryl Reed, Project Officer
(406) 841-5041
dreed@mt.gov

View Documents at:

U.S. EPA
Montana Office
301 S. Park, Room 192
Helena, MT 59626
(406) 457-5034


 


 

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