Sixteen years after 10-year-old Isaac Opper’s science experiment detected elevated levels of the chemical PCB in Lewistown’s Big Spring Creek, cleanup of the waterway may finally be complete.
“I had the easy part,” Opper said in a phone interview.
Opper is now 26 and a graduate student in economics at Stanford University. Although he has left the state, he is still pleased with the cleanup that his grade school science project set in motion.
“It says a lot about the people of Lewistown and Montana in general about how we care about our natural resources,” he said.
Two weeks ago, Mungus Construction of Philipsburg — which was hired to dredge almost 3 miles of the creek to remove PCB contamination in the sediment — completed its work. This was the last step in what has been an exhaustive project to remove the chemical from the waterway, its fish, other aquatic organisms and from the fish hatchery raceways where the PCB-contaminated paint came from.
PCBs, or polychlorinated biphenyls, were used as a coolant in industrial processes like electrical transformers before a 1977 ban was enacted. They were also an additive in paints and caulk. When tested by officials following Opper’s discovery, PCB levels in Big Spring Creek measured up to 46 times the level deemed safe for human consumption.
The contamination in the creek had come from paint used in Fish, Wildlife and Parks’ Big Springs Trout Hatchery along Big Spring Creek. The paint – supplied by Columbia Paints — contained PCBs made by Monsanto. When the paint chipped off the sides of the hatchery, it entered the creek and problems began.
In animals, PCB exposure can cause reproduction and growth problems, as well as skin lesions and tumors. In humans, it’s believed to cause cancer.
The work to remove contaminated paint from the hatchery pools and surrounding property cost close to $10 million, half of which came from a settlement with Monsanto.
The state also paid $5 million to Big Spring Creek landowners as part of a settlement over pollution of the waterway.
The hatchery ended up destroying nearly a half-million trout that were possibly contaminated, and in 2004 FWP issued an order advising against eating any fish from the stream since the chemical builds up in the fish’s flesh. That advisory was lifted this year, but the catch-and-release regulation has been kept because of heavy fishing pressure on the creek. Lewistown's water supply was never threatened.
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So the dredging of the creek was the final step in what has been a lengthy remediation process. Even after the dredging, though, there will still be PCBs in the Big Spring Creek environment.
“The cleanup plan was never intended to get rid of all of the PCBs, because they were found up to three feet deep in the sediment,” said Don Skaar, fish management section supervisor for the Montana Department of Fish, Wildlife and Parks.
To remove contamination that deep, the upper section of the creek would have had to have been rerouted and the streambed dug up. Most of the contamination was found in the stream’s sediment, especially in slower back eddies where they settled to the streambed. It was determined that by removing the sediments, the majority of the PCBs could be eliminated.
That’s where the dredging came in. The work removed 1,530 tons of sediment, which was dewatered in settling ponds and then trucked to a landfill in Great Falls for disposal. The water was filtered before being returned to the stream.
“We’re hopeful it’s accomplishing what we wanted,” Skaar said.
The dredging alone, which included oversight and trucking of the sediment, was a $3.2 million project that took an eight-man crew about three summers to complete.
“Now we go through a period of review where we demonstrate to the (Environmental Protection Agency) that cleanup has been successful,” Skaar said.
To do that, beginning this fall FWP will take samples from different sections of the creek’s bed. The target is to have .189 parts per million of PCBs or less. It will take five years of tests showing a clean bill of health before the creek is pronounced cleaned up.
“It will probably be a couple of months before we know what the results are, which will be our first indication of what our success is,” Skaar said.
Opper, who discovered the contamination, is pleased the creek that he used to swim in as a child is now less polluted.
“Big Spring Creek, in a lot of ways, is Lewistown’s best asset,” he said.