Fish killed in ponds at Aspen Center for Environmental Studies from city office construction mistake |

Fish killed in ponds at Aspen Center for Environmental Studies from city office construction mistake

Dozens of fish have been killed and injured at the Aspen Center for Environmental Studies ponds after a subcontractor working on the new city office building Tuesday drilled into an underground drain system that leads to Hallam Lake, which became comprised when grout from the construction site flowed in.

“It’s a mistake. It’s a sad mistake because it’s a pristine ecosystem, one of the most pristine around,” said ACES Executive Director Chris Lane, adding that the city has been responsive and contrite in its response.

ACES’ onsite manager Tuesday around noon noticed white, murky, turbid water in the center’s indoor tank that was home to trout.

He then realized it was same situation in the three ponds behind the center, which is closed due to the COVID-19 spread but the walking path around the lake is open.

ACES staff tried to transfer roughly 50 fish from the pond to clean water but not all of them made it. Others died in the pond and sank to the bottom, Lane said.

ACES is awaiting state experts to assess the damage and directions on how to clean up the site.

“It does need to be remediated,” Lane said. “We need a water quality expert to tell us what’s in the grout.”

City officials also are investigating how much grout entered the system, said Rob Schober, the city’s project manager, adding that ACES contacted the city when it learned of the situation.

“Our project team took immediate actions to assess the damage and activate a clean-up action plan,” he said. “We are working very closely with ACES on responding quickly. We take our environmental stewardship very seriously and mitigating this is our project team’s first priority right now.”

Much of the turbid water, which Lane described as looking like white paint, naturally has flushed out into the Roaring Fork River, but sediment at the bottom of the ponds and around them remain.

“It’s pretty scary,” he said, adding macro-invertebrates and plant life will likely die, as well. “We would love for this to be removed in a matter of days, not weeks.”

Rifle-based B&Y Drilling Inc. was doing foundation work for the new city offices on Rio Grande Place, just a few blocks from ACES.

Micro-piling activities inadvertently intersected an under drain system below the Rio Grande parking garage, causing a mix of cement grout to be introduced into the city’s dewatering well, according to a news release.

This incident has been reported to the state of Colorado and Colorado Parks and Wildlife.

The city has ceased all micro-piling and foundation work, and the project team is taking immediate steps to ensure this situation does not happen in the future, according to city officials.

“The city is taking this very seriously as the health of the river, lake, wildlife and ecosystem are fundamental to Aspen’s water quality standards, quality of life and environmental values,” said April Long, the city’s clean river program manager.

The city’s drinking water quality is not impacted.