There's a big hole at Caras Park that will house the first major project for the City of Missoula's new storm water utility that will help filter trash and sediment and keep it out of the Clark Fork River.

Storm Water Superintendent Bob Hayes described the project.

“We’re in the process of installing a hydrodynamic separator, which is a fancy term for a  really specialized filter to keep material out the storm water before it goes into the Clark Fork,” Hayes said. “Folks who have been using Brennan’s Wave over the last several years have seen beer cans and coffee cups and cigarette butts coming out of the outfall at the river. Those things won’t be seen anymore once it’s installed and in place.”

Hayes said the hydrodynamic separator is 12 feet in diameter and 22 feet tall, and the cost to install the device will be approximately $220,000, which is being funded through a Department of Natural Resources and Conservation Renewable Resource grant along with matching funding from the Missoula Redevelopment Agency, Missoula Valley Water Quality District, Missoula Parking Commission and the City’s new Storm Water Division, with in-kind contributions from Missoula Parks and Recreation. The unit is being installed by Montana contracting firm Battle Ridge Builders of Belgrade.

“On Thursday, we will be setting the device in there, and for the next several weeks we’ll be backfilling the device and surfacing back over and putting the paver bricks back down,” he said. “Once we’re finished, no one will have a clue that it’s there, except for those folks who are looking at that outflow at Brennan’s Wave and had previously seen the trash and things coming out. They’ll no longer see anything coming out of there but clean water.”

The project is expected to be complete by early December.