Geren Island Water Treatment Plant Ozone Upgrades

The City of Salem has been operating the Geren Island Water Treatment Plant since 1937. Presently, the plant has the capacity to treat up to 80 MGD utilizing biologically active slow sand filtration. However, in the early summer of 2018, the City discovered levels of cyanotoxins in their distribution system that exceeded health advisory thresholds. As a result, one of the longest “do not drink” advisories in the history of the United States was issued.

To address this issue, the City made the decision to upgrade their existing pump station and implement a new 75 MGD ozone treatment system. This new system includes an ozone generation building and an ozone contactor.

To expedite the implementation process, the City opted for the CM/GC alternative delivery method and selected Slayden to deliver this critically important and fast-tracked project. This project needed to provide an operational ozone system by the spring prior to the algal toxin season. We led the development and execution of a complex project delivery and procurement plan to meet the required schedule timelines and enable construction to proceed at the earliest possible date.

We led a demanding project schedule by procuring long lead equipment and materials ahead of time. We were able to accelerate procurement for site investigations and critical early plant improvements. This approach allowed work to proceed onsite approximately three months after receiving the notice to proceed with preconstruction services just after the 30% design milestone. The City also released the construction design for the ozone contactor months before the rest of the project, utilizing the collaborative partnership to address and mitigate potential construction delays.