The contract came in at $309 million. NAVFAC Hawaii had been telling industry to expect $500 million to $600 million.
That gap is the most interesting number in the Red Hill water treatment award, which the Defense Department published August 11 and Naval Facilities Engineering Systems Command Hawaii announced the following day. Hensel Phelps Construction Co. of Greeley, Colorado takes the firm-fixed-price job, with completion scheduled for August 2029.
What the $309 million buys
The plant treats the Red Hill water source that served roughly 93,000 people before the 2021 fuel release contaminated it. The Navy’s drinking-water advisory was lifted in March 2022, but permanent treatment has been in procurement ever since.
Scope is heavy civil and process work in difficult terrain. Granular activated carbon pressure vessels do the treatment. Around them sit modifications to the Red Hill Pump Station and shaft, transmission piping, 26,300 sq ft of new facilities, a 250,000-gallon cast-in-place fire water tank, mechanically stabilized earth walls up to 33 ft tall, and rockfall mitigation across an improvement area of about 25.6 acres. Delivery is design-bid-build, which is unusual for a project of this complexity and is part of why the number landed where it did.
Incremental funding is the risk everyone should read
Only $109.3 million was obligated at award, in fiscal 2026 military construction money. The rest gets funded incrementally, which is standard practice on MILCON of this size and also the single biggest schedule variable on the job. A firm-fixed-price contract with incremental funding transfers price risk to the contractor while leaving appropriation timing with Congress. Hensel Phelps is carrying three years of escalation on Hawaii logistics against a fixed number.
Why the estimate was so far off
NAVFAC published its workload projection in January 2026 and its presolicitation range at $250 million to $500 million. Coming in at $309 million says the bidding market for federal water infrastructure in the Pacific is more competitive than the government modeled, or that the scope tightened between projection and solicitation. Probably both.
One detail worth holding onto: NAVFAC lists 10 million gallons per day of capacity, while the Navy’s May 2026 final environmental assessment limits operation to roughly 5 MGD as an annualized average under the current permit. Those are both true and they describe different things. Anyone sizing follow-on work should use the permit number, not the nameplate.
Related work on Exchange: the Sea-Tac C Concourse expansion shows the same pattern of public owners delivering complex work inside operating facilities.