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Westminster Blvd. Drinking Water Project

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The new drinking water facility design is underway

Thank you to everyone who provided comments on the draft environmental assessment (EA) for the Westminster Boulevard Drinking Water Facility. Comments on the EA were accepted between September 12–October 12 and the comment period closed on October 12.

Comments and questions submitted during the public comment period will be officially reflected and responded to in the final EA and future design phases. There will be additional opportunities to provide feedback as the project progresses. Please stay tuned for more information. 

Environmental Assessment

The public comment period is now closed and the draft EA is viewable at the link below. The final EA will be posted online after public comments and questions have been addressed.

View the Environmental Assessment

View the Project Needs Assessment

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There will be more opportunities to learn more about the project and share your feedback with us. Please sign up for our email newsletter to get the latest information on design progress, the environmental assessment process, open houses, engagement opportunities, and project impacts. 

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Project Summary

The City of Westminster is committed to providing affordable, high-quality water services. Semper and Northwest water treatment facilities currently supply more than nine billion gallons of clean and safe drinking water annually through over 500 miles of pipes to our residents and businesses.

The 54-year-old Semper Water Treatment Facility is nearing the end of its useful life and will soon need to be replaced. In 2015, the City began planning for a new water treatment facility to replace Semper.  Over the past two years, under City Council’s guidance, the City reevaluated the project and considered different options for the facility to better balance the community’s need for clean, safe, and affordable water after the community raised concerns about affordability.

The reevaluation focused on rightsizing the facility and associated infrastructure, which originally had an inflation-adjusted cost of over $300 million. As a thorough reevaluation, City Staff was able to reduce project cost by over $100 million, and City Council capped future rate adjustments to no more than 4.5% over the next decade. The approved Westminster Boulevard Drinking Water Project is a cost-effective, affordable solution with the flexibility to:

  • Replace aging infrastructure and expand if needed.
  • Respond to future state and federal clean water regulations.
  • Build additional treatment processes to respond to potential future wildfire contamination and emerging contaminants. 

Preliminary estimates for constructing the new facility are upwards of $200 million. This preliminary cost estimate ranges from -15% to +30%.  As design progresses, the estimate will become more certain and will be adjusted to market conditions and prevailing construction valuation. 

The new facility will ensure the community continues to have clean, safe, and affordable drinking water for generations to come.

Map of Drinking Water Facility location
Click here for an ADA accessible PDF of the above photo

On April 24, 2023, City Council adopted Resolution 13, directing City staff to pursue the construction of a water treatment facility along Westminster Boulevard between 98th and 104th avenues. The project is currently in the planning, permitting, and design phase, with an expected 2028 completion date.




Associated Projects

The City is also working in conjunction with the following utility projects:

Water Supply Line 

A two-mile, 36-inch-wide waterline would transport untreated water from Standley Lake to the new treatment facility. The new water supply line would connect to the existing Standley Lake waterlines and would connect to the facility at the project site’s southern boundary.

Finished Waterline

A 30-inch-wide finished waterline would deliver clean, safe, and affordable drinking water from the facility to our community. The finished water pipeline would extend approximately one-third of a mile from the facility’s eastern boundary and connect to an existing water main.

Sewer Line

A 650-foot-long sewer line would carry domestic wastewater from the facility to an existing sewer line located east of the project site. 

Map of water supply line

Click here for an ADA accessible PDF of the above map

April 24, 2023 - City Council selection of Option 4, Constructing a new right-sized facility on the Westminster Boulevard site

February 6, 2023

January 23, 2023

Jul 11, 2022

May 23, 2022

April 25, 2022

April 11, 2022

March 28, 2022; pt. 2

February 28, 2022

January 10, 2022

December 21, 2021

Environmental Assessment- Fall 2023

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What does a new treatment plant mean for my water rates? 

City Council incorporated the cost of the new water treatment plant when it approved the historic rate reductions last year. In order to provide immediate relief to rate payers, City Council adopted lower rates within the current three-tiered structure and increased the volumes allotted within each of those tiers in 2022. This significant rate reduction followed previous 10% water rate increases in both 2019 and 2020.  

City Council directed staff to better balance the need to maintain affordable water rates, while maintaining the City’s water system and ensuring the financial health of the water utility into the future.    

After extensive financial modeling, City Council adopted a 4.0% rate increase for 2023 and capped rate increases to no more than 4.5% for the next decade to balance the budget. These moderate rate increases over time support the defined 2023-2027 Capital Improvement Program including the right-sized water treatment plant while ensuring clean, safe, and affordable water for generations to come.