Hypochlorite Building Upgrade

Capital Improvement Project
The Water Bureau will upgrade the Hypochlorite Building at Washington Park Reservoir. Aside from exterior doors, upgrades will happen inside the building. Built in 1981, this simple structure fulfills another critical role: allowing us to serve clean and safe water to the west side of Portland.
The Hypochlorite Building sits surrounded by construction equipment and supplies at Washington Park. It is made of cinder blocks and has a metal roof.
Winter 2023 to Summer 2025
Location Description
Washington Park Reservoir construction site
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We plan to do work at a structure at Washington Park called the Hypochlorite Building. We will replace the failed mechanical systems inside and upgrade the system so we can add chlorination for the future reflecting pools on top of the reservoir. Built in 1981, this simple structure fulfills another critical role: allowing us to ensure consistent, clean, and safe water for our 360,000 customers on the west side of Portland.

This building is not part of the area’s historic designation. The minor changes being made to the outside of this building will be consistent with the existing building style.

Map showing the location of the Washington Park Hypochlorite Building just east of the former location of Reservoir 4.

How does the community benefit? 

This project will help us continue to serve safe and reliable water to Portland’s west side, including downtown, the Northwest Industrial, South Waterfront, and the West Hills.

How will it work?

The water in our system is disinfected with chloramines (a mixture of chlorine and ammonia) to make sure it is safe to serve to customers. When we store the water for a while in one place (like a tank or reservoir), the disinfectant, chloramine, can lose some of its strength. The good news is that our crews test our water daily. So, if we notice a drop in disinfectant levels, we can increase the level of the chloramines. This is known as boosting.

The Hypochlorite Building was built for just this purpose. It gives water a disinfection boost before it is pumped from Washington Park Reservoir to water tanks at higher elevations. The old system was thirty years old and in need of replacement. The new system will continue to boost disinfectant in the water system and will be used to disinfect the future reflecting pools.

What to expect:

  • Timeline: Construction is scheduled to begin winter 2023-24 and should be completed by summer 2025, schedule permitting. 

  • Work to be performed: The selected contractor will remove existing chemical feed pumps, storage tanks and associated piping, and construct new systems in separate rooms. Building upgrades include replacing select doors, door hardware, and the emergency shower, and installing new ventilation, lighting, electrical, and fire sprinkler systems. Because almost all the work is happening inside of the building, most people won’t notice much of a change.

  • Construction impacts/noise: Most of the work will take place inside of a building located within the Washington Park Reservoir Project worksite. Construction noise will include the sound of trucks transporting equipment and supplies, a concrete saw, and workers communicating with each other.

  • Safety: The contractor and their staff will follow very specific guidelines set by state and City rules as well as by the Water Bureau about how to safely handle materials on site.