Water samples taken from the Animas River during the season’s first spring runoff since August’s Gold King Mine spill raise a “red flag” for potential harm to aquatic life in the waterway.
On Feb. 15, the Animas River turned a yellow-brown color that signaled to many community members that the long-term effects of the Environmental Protection Agency’s release of 3 million gallons of concentrated heavy metals are yet to be seen.
“The fact that people in the community noticed ... reflects a heightened awareness of changes in water quality since the Gold King Mine release,” Marcie Bidwell, executive director of Mountain Studies Institute, said Friday in a prepared statement.
From Feb. 15 to March 1, the nonpartisan independent research station collected samples from the Animas River at Rotary Park. Scott Roberts, an aquatic biologist with MSI, said the samples revealed encouraging results but also reasons to be wary.
The good: Most metals concerned with human health, recreational and agricultural use and domestic water supply did not exceed standards set by the Environmental Protection Agency and the state.
The bad: Though levels for short-term exposure did not pose a risk to aquatic life, Roberts said data indicate that if the amount of metals discharging into the basin remains constant for an extended 30-day period, the health of fish and other macroinvertebrates could be endangered.
“It’s definitely a red flag of concern,” said Roberts, citing the high levels of aluminum and iron. “But it doesn’t necessarily affect aquatic life unless it persists longer than spring runoff.”
In the test period, the Animas River ran an average of about 300 to 400 cubic feet per second, nearly double the historical average. Yet, with the EPA reporting that 880,000 pounds of metals were dumped into the basin, many are concerned that peak flows will kick up more contaminated sediment on the river floor. Last year, the Animas ran upwards of 1,000 cfs from May to August, peaking in mid-June at 7,000 cfs.
Ongoing monitoringAlthough the orange plume that lingered three to four days in Durango did not cause a mass die-off of fish and other aquatic life, wildlife officials are closely monitoring the potential impacts of long-term exposure.
Last week, crews from Colorado Parks and Wildlife captured five species of both brown and rainbow trout from the stretch of river from Cundiff Park to the high bridge near Mercury Payment Systems – considered a “gold medal water” fishing spot.
The trout will be sent to the Colorado Department of Public Health and Environment labs in Denver to test the fish’s tissue, which officials hope will show if there’s been an uptake of heavy-metal absorption.
“There’s a concern that the fish can accumulate heavy metals over time,” said Kristy Richardson, a toxicologist with the health department’s water quality control division. “That’s why we’re going back out to look at the levels in the fish again: to see if those levels are constant or if there’s any change.”
Fish samples were first taken from the Animas about a week after the Aug. 5, 2015, Gold King spill. At that time, health officials did not find alarming levels of metal concentrations, and they deemed the trout safe for human consumption.
“Only arsenic, mercury and selenium had detections,” Richardson said. “But they were consistent with levels we see throughout Colorado.”
Now, the concern is that after seven months of repeated subjection to higher-than-usual and potentially toxic metals – such as iron, zinc, copper and aluminum – fish could start showing signs of declining health.
“Because of increased loads of metals in the river, there’s a possibility the fish could bio-accumulate,” Richardson said. “But we don’t know, and that’s why we went out again.”
Jim White, a Parks and Wildlife aquatic biologist who conducted the fish capture, said he doesn’t anticipate metal concentrations will affect whether it’s safe to eat fish caught out of the Animas because the types of metals that drain from mines north of Silverton tend to build up in the trout’s internal organs, rather than flesh.
Still, White said that uptake of metals can stress fish with internal issues such as kidney or liver diseases, and that can lead to secondary complications that ultimately kill the trout.
“The metals themselves may not necessarily kill the fish,” White said. “Usually, it stresses them out to other diseases that typically don’t harm wild fish populations.”
Fishing declinesEven before the Gold King blowout, fish were on the decline in the Animas from a number of factors other than heavy-metal concentrations, including lower water levels in the river, urban runoff and higher water temperatures.
Tom Knopick, a co-owner of Duranglers Flies and Supplies, said as far as on-the-ground observations in town, there’s been no discernible change to trout populations or behavior since the spill.
“Not one little bit,” Knopick said.
Knopick said his shop regularly fields inquiries whether it’s safe to fish the Animas, and through last fall, the number of anglers coming to the area definitely declined.
“Which is unfortunate because there is no impact to the resource,” he said. “It’s the doom-and-gloom media that’s caused the problem as far as we’re concerned.”
Richardson said data taken from the fish samples will be taken in the next month or two. Once vetted by state health department staff, the findings will be made available on the department’s website dedicated to the Gold King Mine incident. Roberts said results from ongoing macroinvertebrate testing would be available in coming weeks, and Mountain Studies Institute will continue to monitor water quality throughout 2016 and make it available on the group’s website.
This story has been corrected to indicate the peak of spring runoff occurs in mid-June.