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Westminster Blvd. Drinking Water Project

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What's Happening Now

The design of the new drinking water facility is underway, with design plans 60% complete. Additionally, the team is working on designing adjacent projects such as a water supply line, finished water line, and sewer line. The water supply line is scheduled to begin construction in early spring of 2025, and the new facility is scheduled to begin construction in late spring of 2025. 

Online Open House

On October 15, we held a public open house for the community to learn more about the project and share feedback on the building design. If you weren't able to attend the open house, please visit our online open house. Comments will be accepted until October 31. 

Visit the online open house

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.  

Semper is nearing the end of its useful life, and the new drinking water facility will make the city’s drinking water supply more resilient to future challenges.  This DWF project includes building a new treatment facility to treat 14.7 million gallons per day (MGD), water supply line, finished water line, and supporting utilities needed to operate the facility. The new facility will ensure the community continues to have clean, safe, and affordable drinking water for generations to come. 

Why a New Water Treatment Facility

Building a new facility allows a controlled phase-out and ultimately a decommissioning of the aging Semper Water Treatment Facility. All the plant’s major systems, including mechanical, electrical, structural, and piping systems, are at or near the end of their service life. Continuing to operate Semper indefinitely increases the risk of failure, which could abruptly and severely limit the city's ability to produce drinking water to meet demand. When the new facility is complete, Semper will continue to operate at a reduced capacity for some time and ultimately be taken offline completely. It will provide modern, reliable infrastructure, ensuring the uninterrupted ability to meet demands for drinking water for decades to come. 

Associated Projects

Along with the water treatment facility, the City is also working on the following supporting utility projects: 

  • Water Supply Line — A new waterline will transport untreated water from Standley Lake to the new treatment facility. The new water supply line will connect to existing supply pipelines to transport untreated water to the facility. 

  • Finished Waterline — A new finished waterline will deliver treated water from the facility to the City’s water distribution system.  

  • Sewer Line — A sewer line will carry wastewater from the facility to an existing sewer line located north of the project site.  

Project History

In 2015, the City began planning for a new water treatment facility to replace Semper. With council’s guidance, the city reevaluated the project and considered different options to better balance the community’s need for clean, safe, and affordable water after the community raised concerns about affordability. On April 24, 2023, City Council approved the financing and construction of a new water treatment facility on Westminster Boulevard.  

Questions?

Please do not hesitate to reach out to the project team, which can be reached by email at waterfacilityproject@westminsterco.gov or by phone at (720) 464-3435.

Thank you for your patience while we invest in our community!

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Documents

Open House — October 15, 2024

Environmental Assessment — Fall 2023

Community Advisory Team — Ongoing

FAQs

Westminster’s two drinking water treatment facilities, Semper and Northwest, provide water to the residents and businesses of Westminster, Federal Heights, and customers in unincorporated Jefferson and Adams counties. Semper provides drinking water for 75% of the City’s water demand and was built over 50 years ago, before modern water treatment regulations and technologies were developed. Northwest, built in 2001, has more modern water treatment technologies than Semper, and provides drinking water for 25% of the City’s water demand.  

The new facility will allow a controlled phase out of the aging Semper facility. 

Continuing to operate Semper increases the risk of failure that could abruptly and severely limit the city’s ability to meet demand for drinking water Semper’s major systems are at or near the end of its service life. These systems include mechanical, electrical, structural, and piping systems. Options to renovate or rebuild Semper on site were evaluated, and building a new replacement facility at a different location was determined to be the most cost effective. The Westminster Boulevard site will have sufficient space to expand as water treatment processes and infrastructure to meet additional need and future drinking water regulations. This phased approach is a financially responsible way to maintain and replace Westminster’s drinking water treatment infrastructure and allow newer portions of Semper to remain operational for the duration of its useable life.  
The first phase of the project will build a water treatment facility that produces 14.7 million gallons per day. This is adequate to treat current water demand and will allow the oldest parts of Semper to be taken offline. The first phase is anticipated to be built by the second half of 2028.   
While a second phase has been considered, it would be depend on future water demand. 
The new water treatment infrastructure is a sizeable investment for Westminster residents. However, the new treatment facility will ensure residents have reliably clean and safe water for generations to come. 

The near- and long-term fiscal plan for the water utility currently includes annual rate adjustments of up to 4.5%. These adjustments support the operations and maintenance of the system, debt service obligations, and the defined 2024-2028 Capital Improvement Plan. This plan includes a new water treatment facility and other important repair and replacement infrastructure projects to ensure clean, safe, and affordable drinking water for generations to come. 

2024 water rates graphic.jpg


We continue to explore what the new facility will look like. We will work closely with a community advisory team and provide the community with opportunities to share opinions during future online and in-person open houses.   

Several consultants are part of the project team: 
  • CDM Smith: Drinking water facility design 
  • Olsson: Environmental assessment 
  • Burns and McDonnell: Water supply line design 
  • HDR: Community outreach and communications, site selection, and modeling 
  • Hazen: Drinking water facility process design 
  • McCarthy: Drinking water facility construction manager, cost estimating, and cost efficiency 

    After the city identified the need for a new drinking water facility, a site selection alternatives analysis was conducted to evaluate sites suitable for the construction of a new facility. The site selection process identified more than 50 sites for initial consideration. The initial site list was narrowed to nine using three categories of evaluation criteria:  
    • Community 
    • Engineering 
    • Site characteristics 

    The next phase of the process further reduced the list to three recommended sites. After further consideration, the site at 98th Avenue and Westminster Boulevard was selected.  
    The new facility is not anticipated to have any strong odors associated with it because it is an indoor facility dedicated to treating drinking water. It is not a wastewater facility.  
    The dewatering basins on the north side of the property are not expected to generate any sulfur odors during normal operations. The solids that accumulate in the basins will be removed periodically, usually after a freeze/thaw, draining/drying cycle over the winter. 

    Final design is not yet complete. The current draft design of the drinking water facility (60%) shows building heights ranging from 11.3 to 49.4 feet tall with an average height of 23.8 feet. The tallest building would be the two-story process building. The water tank is designed to be on the ground, not an elevated water tower. 

    The finished waterline is sized to exceed the water treatment capacity for phase 1. An additional finished waterline will be built if new water treatment trains come online in the future. This will help create reliability in the water system and make the system more dependable in the event of water main breaks or other issues that can arise unexpectedly.

    There will be dewatering basins on the northwest area of the property that will be filled and emptied on a cycle. Mosquito problems are not anticipated, but they will be mitigated if they occur. 

    Common milestones for construction projects are 30%, 60%, and 90% design. These indicate the level of design that has been completed to that point and are often opportunities for public or community input.   
    • 30% design – Very high-level design with major project elements defined. The project team is determining any fatal flaws, defining the scope of the project, and refining the cost estimate. 
    • 60% design – Designs of major project components are completed and refined following input from the 30% milestone. The design team confirms that the plans and specifications will meet project objectives.  
    • 90% design – Details and concepts are refined following input from the 60% milestone. This is often considered final design and all that usually remains is ensuring permits are in place prior to construction beginning. 
    The requirement to carry out an environmental assessment (EA) is necessary when acquiring federal funding for a project, and it needs to be initiated early in the process to stay on track with the overall project schedule. Initially, the City planned to pursue state and federal funding to make the best financial decisions for ratepayers.

    After a comprehensive financial analysis was completed, it was determined that funding the project through bond issues would be the most fiscally responsible option. Because federal funding will not be used for the project, the EA is no longer required.

    The city is still committed to implementing best management practices that protect wildlife and our natural resources as it would have under the EA review. Throughout the project, the City will coordinate with Colorado Parks and Wildlife (CPW) to protect wildlife and associated habitat ensure the project complies with CPW guidelines.
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