Frequent contact with waste tailings on the Iron Mountain Mine and Mill (IMM) site, the Flat Creek floodplain, and the town of Superior could harm people's health, reports a federal health assessment. Levels of arsenic and lead are of public health concern if residents, particularly children, repeatedly contact areas affected by waste tailings in and around Superior, MT.

The Agency for Toxic Substances and Disease Registry (ATSDR) looked into possible health effects from heavy metals in waste tailings -- materials left over from the mining process after ore has been removed -- from the IMM site in soil, creek water and drinking water. The agency finalized its report this month after accepting public comments.

The IMM site formerly was home to mining and milling operations, and leftover waste tailings have contaminated portions of the IMM site and the Flat Creek floodplain. Waste tailings were also used in the town of Superior as fill material for roads, driveways, and yards. In 2002, the U.S. Environmental Protection Agency tested the soil in town and removed some mine tailings used as fill material because of possible short term health risks. This ATSDR assessment looked at the possibility of both short and long term health risks from past, current, and future contact with the waste tailings contamination.

Results included:

• Soil: Arsenic and lead levels are of public health concern for children and adults who repeatedly contact areas affected by waste tailings on the IMM site and Flat Creek floodplain. Because the contaminated areas at the IMM site and floodplain area are posted with warning signs, ATSDR expects recreational activities in these areas to be infrequent.

In town, heavy metals detected in soil at most residential and non residential areas are not at levels of health concern. However, four residences tested have lead levels and two of these four residences have arsenic levels that could be problematic for children who play regularly in the soil. The potential also exists that additional properties in town that were not tested might contain waste tailings.

• Flat Creek: Harmful health effects are not expected for children and adults who have skin contact or drink small amounts of Flat Creek surface water while wading and fishing. Using creek water for drinking, showering, bathing, cooking, and washing dishes is not expected to cause harmful health effects. Nonetheless, scientists found that levels of antimony and lead in the creek exceed regulatory guidelines, and the creek has occasionally been used as a drinking water source. ATSDR recommends efforts to reduce drinking water exposures when chemical levels are above regulatory guidelines. Children who drink one liter or more of Flat Creek water per day could have blood lead levels of concern.
• Hall Gulch: Surface water in the Hall Gulch area would be at levels of public health concern if the water were drunk frequently. However, ATSDR would not expect people to drink or wade in this shallow, reddish-brown surface water.
• Drinking water: Chemicals found in water from city wells, Flat Creek Spring, and one private well tested were not at levels of public health concern. However, in the past, antimony levels in Flat Creek Spring and the private well exceeded regulatory guidelines. ATSDR did not have enough data to evaluate water from private wells on the north side of town.

ATSDR recommends further efforts to minimize exposure to the contamination, such as removing waste tailings deposits on the IMM site and floodplain, and continuing to post warning signs about arsenic and lead at the mine site and floodplain area. The agency also recommends continued work with the community to determine which areas of town should be studied further.

A copy of the public health assessment is located at:

Mineral County Courthouse
300 River Street
Superior, MT 59872
Contact: Tim Read
Phone: 406-822-3526

Or

Mineral County Public Library-Superior
301 2nd Avenue East
Superior, Montana 59872
Contact: Guna Chaberek
Phone: 406-822-3563

The report can also be found online at http://www.atsdr.cdc.gov/HAC/PHA/HCPHA.asp?State=MT

For more information, community members may contact Dan Strausbaugh at (406) 457-5007.

Members of the news media can request an interview by calling the NCEH/ATSDR Health Communication Science Office at 770-488-0700.