2024/07/10 Council Agenda Packet

EXHIBIT A1 City of Everett – Replacement of Reservoir 3 Contract Amendment No 1 1 Scope of Services SCOPE OF SERVICES Background Reservoir No. 3 was originally constructed nearly 100 years ago as a below grade square concrete reservoir with a capacity of 20 million gallons (MG). A cover was constructed over the reservoir approximately 30 years ago and has been determined to be in need of repair. HDR performed a seismic evaluation of Reservoir No. 3 as part of the 2020 Comprehensive Water Plan (CWP) and determined that retrofitting the reservoir’s cover to meet current seismic codes would be cost prohibitive and difficult to construct. Taking the existing reservoir offline for an extended period of time is not feasible. In addition, there is a significant risk that the existing reservoir’s embankments could not survive a large seismic event (Magnitude 7.4 South Whidbey Island Fault (SWIF) Scenario as required by IBC 2018/ASCE 7-2016), causing a structural failure of the reservoir. The City of Everett, Washington (City) recently decided to embark on this replacement of Reservoir No. 3 as quickly as possible because of the reservoir cover’s rapidly deteriorating structural condition. The objective of this project is to design and prepare plans, specifications, and estimate (PS&E) for the construction of a minimum of two ground storage reservoirs (GSR) totaling a minimum of 20 MG storage to meet current seismic code requirements. The project will be implemented in two separate design phases and performed under separate construction contracts. Phase 1 includes the construction and completion of two 4 MG reservoirs, resulting in a total of 8 MG of storage, while the existing 20 MG reservoir remains in service. Phase 2 will begin after the Phase 1 reservoirs are constructed and placed in service. In Phase 2, the existing 20 MG reservoir will be demolished, and a single reservoir with a minimum storage capacity of 12 MG will be constructed. During the 30% Design Review Workshop on July 10, 2023, the concept of constructing a single 8 MG reservoir in the Fire Training Facility in lieu of the two 4 MG reservoirs as part of Phase 1 was proposed by the City. This was made possible by the Fire Department expressing a willingness to permanently vacate the site. This concept warranted additional consideration and the City authorized Task 800.2 as part of the Management Reserve Authorization No. 2 to continue to develop the concept which will delay the overall schedule of the contract. This concept was determined to be feasible and the City authorized HDR to proceed forward with revising the PDR based on the single 8 MG reservoir on July 20, 2023. On October 5th, 2023 HDR presented the City with a draft of Amendment 1 to cover additional design services associated with the revised reservoir location including additional geotechnical explorations and sampling for per and polyfluoroalkyl substances (PFAS). This was updated again on October 25th, 2023 to add three additional geotechnical borings for PFAS. The total budget required exceeded what was remaining in the management reserve following Task 800.2. The City authorized these efforts proceed utilizing budget from future design phases and a future amendment be executed after Phase 1 bidding based on actual invoiced amounts and would include engineering services during construction for Phase 1 construction. This updated amendment includes costs incurred during the finalization of Phase 1 design, engineering services during construction for Phase 1, additional effort to address PFAS during Phase 2 as well as a replenishment of the management reserve.