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$600 million makeover on tap

New treatment plant and high-capacity pipeline part of one of the largest renovation projects in Denver Water history.

Denver Water is launching a major construction project in Jefferson County, including building a state-of-the-art treatment plant next to Ralston Reservoir, north of Golden, Colorado.

The new treatment plant is the centerpiece of the North System Renewal, a series of projects to upgrade the infrastructure that brings water from the West Slope to the Front Range.

With a projected cost of $600 million, the project includes building an 8.5-mile water pipeline, modifying Moffat Treatment Plant and building the new Northwater Treatment Plant.

“The North System was built back in the 1930s and is in need of repair,” said Bob Mahoney, chief engineering officer at Denver Water. “Upgrading the whole system ranks among the biggest renovation projects in Denver Water history.”

Building on Moffat's legacy

The new treatment plant will provide the bulk of the north system's water treatment with the Moffat Treatment Plant in Lakewood, the oldest of Denver Water’s four water treatment plants, serving as a supplemental treatment facility.

Moffat Treatment Plant in Lakewood is Denver Water’s oldest active water treatment facility.

“Moffat was cutting-edge in water treatment back in the 1930s, but it’s getting old,” said Andrea Song, Moffat Treatment Plant supervisor. “We’re building a new plant with modern water treatment and operational technology.”

Filters are a key component of the new plant. “Water filters are the heart of any treatment facility,” Song said. “The new plant will have deeper filter beds that are able to remove more particles, contaminants and impurities, which will give our customers a higher quality of water.”

Building for the future

The new Northwater Treatment Plant will be able to produce up to 75 million gallons of water per day and could be expanded to handle more capacity if needed in the future. The plant will incorporate sustainability practices throughout its operations, including alternative energy sources like hydropower.

The Moffat site will continue to play a role in the delivery system by operating at a reduced level as needed and transitioning to a facility that stores water from the new treatment plant and distributes it to Denver Water customers.

New pipeline in Jefferson County

The new 8.5-mile water pipeline will replace the existing pipeline that was built in the 1930s.

“We’re seeing leaks and cracks in the pipe, so we’re being proactive and replacing it before we have a serious problem,” Mahoney said.

Denver Water will build a state-of-the-art treatment plant next to Ralston Reservoir in Jefferson County.

The new pipeline will follow the same corridor as the existing pipe, stretching from Ralston Reservoir, through parts of Jefferson County, Arvada, Wheat Ridge and Lakewood. Residents along the corridor can expect to see impacts in their neighborhoods during construction.

“The pioneers who built this system had vision and did their homework,” Song said. “We’re doing the same today to make sure what we build lasts another 80 to 100 years.”

Design of the new treatment plant is underway, and the first phase of construction for the new pipeline began in fall of 2017. The entire project is scheduled to be completed in 2024.

Residents can view an interactive map on for construction updates.