With the discovery this week of elevated levels of lead and arsenic in Sandy, another name - Mingo Smelter - has been added to a growing list of hazardous sites in the Salt Lake Valley.
While downplaying the immediate danger of the contamination at the eight-acre property in west Sandy, state and city officials are warning residents to take some precautions."We're working closely with the city and area residents to reduce the risk," said Kenneth Alkema, executive director of the Utah Department of Environmental Quality.
Those steps include alerting residents to the risks; further analysis of the soil; an assessment of the extent of the contamination; and a town meeting to explain the problem and discuss possible solutions.
The meeting will be held at 7 p.m. Thursday, Sept. 12, in the Sandy City Gymnasium, 440 E. 8680 South.
The elevated lead and arsenic levels at the Mingo site, 50 E. 9000 South, were detected late last week by the Utah Department of Transportation, which was conducting an environmental study on the widening of 9000 South from State Street to 700 East.
Tests revealed lead levels between 550 and 8,500 parts per million on the site and as high as 34,000 ppm alongside the road. Levels above 500 ppm in a residential area are considered unacceptable by the Environmental Protection Agency.
Elevated lead levels were also found in soil samples taken from residential properties north of 9000 South between 60 East and 120 East.
Alkema said the contamination appears to be confined to the surface, much like that at the Sharon Steel site in Midvale. Both were smelter operations, which means heavy metals probably were deposited atop the ground from windblown and smokestack sources, as well as in tailings and slag deposits.
Some sort of cleanup will be necessary, Alkema said, "but we don't know yet if it will be over the long-term, as it is at Sharon Steel, or the short-term, as at Bingham Creek."
An emergency cleanup is under way along Bingham Creek in West Jordan, where lead from old mine tailings washed deep into the soil in what is now a densely populated area.
Sandy City Administrator Byron Jorgenson said city officials were aware of the existence of the Mingo Smelter property as a historic feature but were unaware of the contamination until state officials notified them this week.
The city has since hired its own consultant to interpret the test results and other information. "We want to do whatever is necessary to protect the residents of this community," Jorgenson said.
The Mingo site is surrounded by a number of businesses, a city fire station and older homes. Jorgenson said that people have been living in the area for more than 100 years without any discernible problems.
He said health risks at the fire station appear to be minimal because any contaminated soil would have been covered with asphalt, concrete and new topsoil.
Also, Jorgenson said extensive tests indicate that all of the water wells in the area are "very clean," with mineral levels well within state and federal guidelines.
The primary risk associated with lead-tainted soil is through inhalation or ingestion. Alkema said residents can minimize the risk by staying away from the soil.
Noting that the average age of residents in the area is 60, Alkema said few children are being exposed to the site. Soil samples at a nearby day-care center revealed no elevated lead levels, he added.
"We think we have the hot-spot pretty much circled," Alkema said, identifying the "hot spot" as the Mingo site itself and the ground directly bordering it.
Called the Mountain Chief Smelter when it was built in 1873, it was taken over by the Pennsylvania Lead Co. and renamed the Mingo Smelter in 1876. During its peak, the smelter operated seven blast furnaces and processed 595 tons per day. It was purchased by American Smelting and Refining in 1898 and dismantled in 1902, according to a state fact sheet issued Tuesday.