Working Through the Design Collaboratively - Preconstruction Phase of Plum Island’s Phase 3 CIP


  • Jared Hartwig - Hazen and Sawyer

This presentation will discuss the background and design of the Plum Island WPCP Phase 3 Capital Improvements project, specifically related to the collaborative design effort with the contractor as part of a Construction Manager at Risk (CMAR) contract. The purpose of this presentation will be to highlight the design considerations and decisions made from the Master Plan to final design documents for the 36 mgd facility. The presentation will serve as a transition between the ‘One Utility Owner’s Approach to Procurement of a CMAR’ to the ‘Turning Dirt Before Finalizing the Design?: Construction of CWS’s Plum
Island CMAR Project’.

Following the completion of the latest Plum Island WPCP Master Plan update, improvements for the Phase 3 Capital Improvements Project were identified. These improvements were recommended to improve plant operation and provide improvements to outdated facilities. Facilities recommended for the Phase 3 Improvements include the following:

  • 150 mgd Preliminary Treatment Facility
  • Two (2) 110-foot primary clarifiers
  • Anoxic Selector with Mixed Liquor Distribution Improvements
  • One (1) Final Settling Tank
  • Site-wide Non-Potable Water Improvements
  • New Electrical Distribution and Emergency Power Generation Facility

Due to issues with site availability a CMAR approach was selected to improve the design related to construction sequencing, schedule and available funding. A preliminary design package was prepared and distributed to contractors for proposals including plans for the following facilities. Following selection of the CMAR contractor, the contractor was instrumental in continuing design from Preliminary to Intermediate design prior to determining the Guaranteed maximum Price (GMP) and continuation to final design.

For more information, please contact the author at

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