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King County WTD – North Lake Sammamish Flow Diversion Project


The contract entails engineering planning, design and related services for the diversion of up to 42 mgd of 20-year peak flow from the North Lake Sammamish Basin to the Brightwater Treatment Plant by 2021. The contract will be performed in phases and P&M is anticipated to support the Alternative Analysis, Predesign through Final Design.


P&M as a sub to CH2M is tasked to provide cost estimating and scheduling services initially for the Alternative Analysis and Selection phase.

Scheduling includes development of an overall project schedule, statusing of the project schedule, development of construction schedules for use in the Alternative Analysis.

Cost estimating services entail development of capital cost for five (5) alternatives. Cost estimates are Class 5 following the Association for the Advancement of Cost Engineering International (AACE) Recommended Practice RP 18R-97, Cost Estimate Classification System – as applied in Engineering, Procurement and Construction for the Process Industries and the County’s LCC model. Basis of Estimate (BOE) will submitted documenting the estimating approach and assumptions.

Project Duration

2018 (Phase 1) – project was cancelled