Diesel-tainted soil slows bridge-related utility work
Crews doing utility work under River Street as part of the larger Grand Avenue bridge project were halted in late March when they came upon soil contaminated by diesel fuel.
The area, which was the site of several gas stations through the years, is in the process of being cleaned up, project spokesman Tom Newland said. He added that it’s impossible to know the source of the contamination, which was found within existing right of way owned by the Colorado Department of Transportation.
It’s not known yet how much soil will have to be removed from the area and replaced with clean fill. Contractors do not expect the incident to cause overall delays in the $126 million bridge project, which is scheduled to conclude in 2018, with the existing bridge to be closed in late 2017 before the new one opens.
An environmental assessment done before the project began warned that petroleum-contaminated soils might be discovered during the work, Newland said.
“Finding potentially contaminated soils on a road or utility project is actually fairly common for projects within city limits or urbanized areas,” Newland said in an email. “You can spend money and time doing up-front testing, but you never really know what you will find until you start digging. This is why CDOT has a specification for procedures in the event that contaminated soils are discovered. In addition to this specification, CDOT has contingency in the project’s budget to be used for remediation if contaminated soils are discovered.”
When the contamination was found, around March 28, “we stopped work immediately on River Street and soils samples were taken and sent to the lab for testing,” Newland said. “After the testing was completed, a plan to remove the soils was developed by the contractor and approved by CDOT. The contractor is now implementing that plan.”