Frisco's wastewater treatment plant will get a $1.25 million upgrade this spring, including a new ultraviolet disinfection system. According to Butch Green, manager of the Frisco Sanitation District, the new system will use ultraviolet lights to remove 100 percent of the fecal coliform bacteria in the wastewater. Currently, the bacteria is removed with filters, which Green said are primarily designed to remove phosphorous. Increasingly, Green said, new regulations have ratcheted down the amount of the bacteria the plant is allowed to discharge into Dillon Reservoir.
“The machinery we've had for the past 20 years has just reached its limit,” Green said. Previously, the plant was allowed to discharge up to 12,000 parts per million of fecal coliform bacteria monthly, and that's been scaled down to a range of 143-258 ppm. With the new ultraviolet disinfection system, it'll no longer be an issue since the lights will zap all of the bacteria, Green said.
The UV system will cost the sanitation district about $600,000, but an Energy Mineral Impact Assistance Grant from the state of Colorado will take care of nearly $400,000 of that. The remaining cost will be covered by the district's reserve funds.
In addition to the new UV system, the district is using another chunk of reserve funding to replace two “equalization basins” at the facility. Green said these are the concrete dishes visible from Summit Boulevard that house large ponds of water for filtration.
“We didn't realize when we built them that junk flying around in the air collects on them,” Green said. “We even have skateboarders up there sometimes.”
The new basins won't be exposed to sunlight as the present ones are, eliminating another problem Green said they've had with algae growth. The basin replacement will cost another $650,000, bringing the total of the upgrades to $1.25 million.
