Denton's plan to add 20 million gallons a day of drinking water capacity at the Ray Roberts Water Treatment Plant now carries a construction estimate of $628 million, according to a quarterly project update the Public Utilities Board receives at its 9 a.m. meeting today.
The expansion is still in the preconstruction stage. The presentation from the Water Utilities planning and engineering division puts the start of construction in the second quarter of 2027 and completion in the second quarter of 2032.
The added treatment would come from low-pressure membrane units, along with an upgraded raw water pump station, chlorine dioxide disinfection, intermediate ozone contactors, new flocculation and sedimentation basins, a transfer pump station and another clear well.
Freese and Nichols holds the design contract, listed at $21,184,000. Archer Western Construction, the construction manager at risk, has a preconstruction fee of $2,814,293.
Where the design stands
Staff reached 30% plans and a cost model in April, according to the slides. Pilot studies of inclined plate settlers and membranes are in their final phases, and membrane autopsies are planned for the end of October, with the results going to the Texas Commission on Environmental Quality for approval.
The next design milestone, 60% plans, is set for January, and an early package of work is scheduled for the second quarter of 2027.
Upgrades nearly done, and one project back to bid
A separate $40.8 million construction contract with Archer Western to boost the same plant's rated capacity and performance reached substantial completion on June 8. That work replaced valve operators and filter valves, swapped the media in all eight filters for granular activated carbon and added a backwash storage tank and a building for variable frequency drives.
Generator controller upgrades are due to wrap up in October, leading to final completion. TCEQ approved the plant's uprating protocol in September, and staff expect to finish the uprating demonstration by the end of 2026.
A chemical overhaul at Ray Roberts is taking longer. The project would replace the plant's bulk chlorine gas system with sodium hypochlorite and its anhydrous ammonia system with liquid ammonium sulfate. When the city sought construction bids in September 2024, it received a single bid and rejected it because the price was too high, the update says.
