The state said it took about 350 samples along the creeks, all in the stream bed and bank and water found within creek bed, from the Lexington Avenue overpass to the west end of Butte Reduction Works. Samples were also taken in wetland ponds near the Blacktail Berm, just behind the Chamber of Commerce building on George Street.

The vast majority of the samples came back exceeding federal benchmarks for copper, lead, arsenic, cadmium and zinc, Ford told The Montana Standard after the meeting.

Mercury also showed up in a couple of samples taken near the former Butte Reduction Works area. That location is now the county’s hot plant, located within the Slag Walls just west of South Montana Street.

The sampling took place over four days in April and May during normal stream flow.

The Environmental Protection Agency has long argued that Silver Bow Creek’s normal stream flows do not show exceedances. But this new data collection gathered by the state did not look at the stream but at the sediment under and around the stream.

During a robust public comment session, people questioned why this data wasn’t known before and why the state had to pay for the sampling work.

“It’s been 10 years since the ROD (record of decision) was signed, and there were a couple of decades before the ROD,” Ford said. “You can draw your own conclusions.”

Nikia Green, Environmental Protection Agency project manager for the Butte Hill, told The Standard after the meeting that the record of decision – the document that lays out the mining damage and how to clean it up – calls for cleaning the bed and bank along that portion of Silver Bow and Blacktail creeks. Although EPA has not gathered this data before, Greene said the information is not new.

“We’ve known contamination was there since 1947,” Greene said.

Ford also said during his presentation that this is not really new information. During the lower Silver Bow Creek cleanup, led by Department of Environmental Quality, some studies indicated contamination sources in the area of the creeks from Lexington Avenue to the old Butte Reduction Works site. But specifics were not known.

In a few of the samples, the contamination came back 20 times the federal benchmark. Because the contaminants are located within sediment and soil, there are no federal or state water quality standards. Instead, safe levels are established as “benchmarks,” meaning it is not fully regulated.

Greene said the information collected by the state is “a good thing.”

The state is sharing the information with EPA. Greene said the federal agency will review the data.

Questions arose on whether the state would get reimbursed by ARCO for doing the study, especially if the data contributes to Superfund cleanup.

“In a perfect world,” NRD program director Harley Harris said.