Title
Discuss and consider action to approve a change order to the construction contract with PLW Waterworks, LLC., in the amount of $15,793,187 associated with the Water Treatment Plant Expansion Project and authorize the City Manager to execute the same.
Summary
The City awarded the construction of the Water Treatment Plant Expansion Project to PLW Waterworks, LLC (PLW) in November 2022. Construction began in January 2023 and work is proceeding at the Lake Pump Station and at the Water Treatment Plant with no delays.
The current design of the membrane system for the 30-MGD plant expansion was based upon retrofitting existing building as recommended from a previous feasibility study performed by others. During the discussions related to optimizations of the facility prior to contract award, the contractor expressed concerns related to the retrofit of the existing building, proximity of ongoing treatment modules, and necessity for multiple trades working in very close proximity and the added risk to ongoing operations and maintenance staff working in the same areas while continuing to operate an active facility. This presented a significant amount of discussion about overcoming this challenge in light of high costs of construction, the pre-purchased membrane equipment and the timeline to present options for consideration and feasibility.
In the time since construction award, the Engineer of Record, Ardurra Group, the Construction Manager, Carollo Engineers and the contractor PLW have worked cooperatively with staff to develop a new building with a secondary train of membrane filtration that will provide the expansion, reduce risk and provide the building for the future expansion at the present day construction value. The cost of construction at this time is still more than the original contract, yet less than it will be in the future in future dollar value.
The proposed change order includes the early order of magnitude cost for a new building to house the new membrane filter treatment units. The new pre-engineered metal building housing the new membrane basins, new membranes strainer and filtration equipment. The new building will house new clean in place pumps, piping, valves and storage tanks, backwash pumps and tanks. Other items include a new air compressor room, two electrical rooms, a restroom, a storage room and a mechanical room, a new precast concrete building to house two new air scour blowers and piping.
This will greatly improve operational plant maintenance, constructability, and minimize treatment process interruption during construction. This new building will both reduce risk and maintain plant drinking water production as required. A new membrane building provides better operability, maintenance, and enhances system operational flexibility in the future, allowing for separate treatment trains to be brought on and off line as needed for maintenance.
If approved, the construction would progress with the design at the same time, and will not add time to the project construction schedule. The funding the City has in place will support this change.
This change order is in the amount of $15,793,187, bringing the PLW final contract value to $162,049,869.54. The plant is expected to able to start delivering additional drinking water capacity in May 2026.
Prior City Council Action
September 14, 2021 - City Council approved a resolution approving Competitive Sealed Proposal method of project delivery for the Water Treatment Plant Expansion.
January 25, 2022 - City Council approved a contract with Memcor/Dupont to supply membrane filters for the Water Treatment Plant Expansion Project.
May 10, 2022 - City Council approved a contract with Alterman Inc.to supply electrical equipment for the Water Treatment Plant Expansion Project.
November 8, 2022 - City Council approved a construction contract with PLW Waterworks in the amount of $146,256,682.52.
Deadline for City Council Action
Action is requested on August 8, 2023.
Funding Expected: Revenue __ Expenditure _X_ N/A __
Budgeted Item: Yes X No __ N/A __
Amount: $15,793,187
1295 Form Required? Yes No _X_
Legal Review Required: N/A _X_ Required __ Date Completed: ___________
Supporting documents attached:
Change Order
Recommended Action
Approve a Change Order to the construction contract with PLW Waterworks, LLC., in the amount of $15,793,187 for the Surface Water Treatment Plant Expansion Project and authorize the City Manager to execute same.