When we hear reports by fisheries biologists of continuing recovery of Silver Bow Creek it’s difficult to comprehend the challenges of restoring a fishery, as well as continuing challenges that still threaten the stream.
Silver Bow Creek was the topic at last week’s Brown Bag Lunch program at the Butte-Silver Bow Public Archives, and judging by the capacity crowd it’s a topic of great public interest.
Joe Griffin, a geologist and former environmental remediation consultant for the Atlantic Richfield Company (ARCO) told the story of the thriving fishery of pre-mining days to industrial sewer to a recovering fishery.
An oral history sound bite of the late Tony Inchachola, a Salish Native American who resided in Butte, recalled tribal memories of a crystal clear mountain stream called Snt’ apqéy, teeming with bull trout, that miners renamed as Silver Bow Creek.
Griffin noted that streams typically have three sources of water: flows from upstream, flows from groundwater, and water from storms that enter the stream. All of those water sources are complex parts of the Silver Bow Creek puzzle.
While the creek was used for drinking and beer brewing in the early years, early smelters ruined the creek, using it as an industrial sewer, dumping slag and other smelter waste in or next to the creek.
Smelters, such as the Parrot Smelter, near today’s Civic Center, dammed up the creek to create ponds, as water was necessary for the smelting process.
During the century of underground mining on the Butte Hill, huge pumps sucked groundwater out of the mines and dumped a constant stream of water contaminated with heavy metals and acids. As bad as that was, Griffin described ARCO’s decision to turn off the pumps when the company discontinued mining operations as “the worst decision ever.”
The water filled the thousands of miles of underground mine shafts, and began filling the Berkeley Pit. Further, the flooding of the underground mines meant that remaining copper ore in the underground workings are lost forever. In spite of the billions of pounds of copper that were extracted from the Butte Hill, Griffin estimates that two-thirds of the copper ore remains.
The copper ore concentrator plant built in the 1960s complicated upstream water sources, as waste rock and tailings are stockpiled in a rock dam high above the Berkeley Pit. Water from the headwaters of Silver Bow Creek and other mountain tributaries gets used in the current Montana Resources concentrator and gets treated for re-use. But, those waters are lost to a recovering Silver Bow Creek.
While the basic problems of mining and smelting waste are complex, the great flood of 2008, the worst known flood on the watershed, sent a surge of mining waste and smelter waste all the way downstream to Missoula.
When cleanup finally began, it turned out that streamside tailings, nasty as they are, were also the simplest to deal with. You dig them out and replace them with clean soils. That doesn’t make it easy, however, considering the amount of mining waste that was removed after the Milltown Dam east of Missoula was dismantled.
Continuing issues are heavy metals and acids in several contaminated areas of Butte, which continually leach into upper Silver Bow Creek. Storm runoff from Butte Hill also dumps mine waste into Silver Bow Creek. There is continuing pollution coming from smelter waste buried under the slag walls near Montana Street.
With all the continuing issues, it still seems a miracle that after cleanup of Silver Bow Creek and the creek’s flood plain, that fish started moving into the stream. Brook trout moved down from Blacktail Creek, the little stream that merges with Silver Bow Creek near the Chamber of Commerce. Westslope Cutthroat trout have moved in from German Gulch and Brown’s Gulch west of Butte.
But, like the ballpark in the baseball movie, Field of Dreams, build it and they will come.
The next Brown Bag Lunch program will be on April 26, with Butte-Silver Bow’s historical preservation officer, Mary McCormick telling about Butte’s mostly forgotten early oil refinery industry.