Regional Wastewater System
title
Rowlett Creek Regional Wastewater Treatment Plant Peak Flow Management Improvements, Phase II; Project No. 301-0471-17; Construction Manager At-Risk Work Authorization No. 1
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SUBJECT
recommendation
Authorize funding in the amount of $20,281,346 to Archer Western Construction, LLC, Construction Manager At-Risk (CMAR), for Work Authorization No. 1 for the Rowlett Creek Regional Wastewater Treatment Plant (RWWTP) Peak Flow Management Improvements, Phase II. This includes all associated CMAR fees, construction support costs and contingencies.
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PURPOSE
The CMAR has submitted a Work Authorization No. 1 for the Train A Diffusers and Air Piping Improvements to meet anticipated loading demands and treatment capacity. Future amendments will be presented to the Board as remaining work authorization packages are developed, procured, and evaluated.
RECOMMENDATION
The Executive Director and NTMWD staff recommend the Board of Directors authorize the Executive Director to execute Work Authorization No. 1 to the Construction Manager At-Risk as follows:
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CMAR: |
Archer Western Construction, LLC (Archer Western) |
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Scope: |
Construction, Rowlett Creek RWWTP Work Authorization No. 1 |
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Project: |
No. 301-0471-17, Rowlett Creek Regional Wastewater Treatment Plant Peak Flow Management Improvements, Phase II |
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Amount: |
Work Authorization No. 1: $20,281,346 |
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Committee: |
This will be an item on the December 17, 2025, Wastewater Committee meeting agenda |
DRIVER(S) FOR THIS PROJECT
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Strategic Objective: |
1.1: High Quality Services 1.4: Reliable and Resilient Systems |
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☒ Regulatory Compliance (Pre-emptive) |
☒ Asset Condition |
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☒ Capacity |
☐ Redundancy/Resiliency |
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☐ Relocation or External Requests |
☐ Operational Efficiency |
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☐ Safety |
☐ Administrative |
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☐ Policy |
☐ Other _____________ |
BACKGROUND
PROJECT PURPOSE
• The Rowlett Creek Regional Wastewater Treatment Plant (RWWTP) serves the cities of Plano and Richardson and has the capacity to treat 24 million gallons per day (MGD) annual average flow and 77.5 MGD peak 2-hour flow.
• In 2014, preliminary engineering efforts determined that a phased expansion to achieve peak flow capacity of 120 MGD at Rowlett Creek RWWTP has lower overall capital and operating costs than providing conveyance redundancy and further peak flow expansion to Wilson Creek RWWTP. The peak flow improvements will ultimately increase the peak flow capacity to 120 MGD through phased improvements.
• Phase I construction, Project No. 301-0328-13, was completed in 2023 and increased the peak flow capacity of the treatment plant from 60 to 77.5 MGD. Phase II will increase the peak flow capacity to 95 MGD by implementing improvements to the existing treatment facilities. A planned future Phase III will increase the peak flow capacity to 120 MGD by the installation of a secondary clarifier and associated improvements.
PROJECT COMPONENTS
• Renewal of Junction Box No. 1 and associated manholes and piping
• Additional pumping capacity at the Wet Weather Pump Station
• Additional pumping capacity and rehabilitation to the Plano Lift Station
• New Train A Blower Building
• Conversion of aeration basins to a step feed process at Train A and Train B
• Train A secondary clarifiers rehabilitation and capacity improvements, including new return activated sludge (RAS) pumping
• Ferric sulfate storage and feed facility
• New filtration facility with disc filters
• New ultraviolet light (UV) disinfection facility
• New reuse water pump station with sodium hypochlorite feed
• New effluent flow metering structure
• New outfall pipe
• New generators for backup power
• New solids building
• Temporary dewatering building/future storage and maintenance building
• Demolition of the existing thickening building, dewatering building, maintenance and chemical storage building, truck load out bays, and lime storage and feed systems
• Sitework, yard piping, electrical and supervisory control and data acquisition (SCADA) system improvements to support new components. SCADA system improvements include a fiber optic network around the RWWTP to create a ring architecture
Work Authorization No. 1 - Train A Diffuser and Air Piping Improvements
o Selective demolition within Train A Aeration Basins 1 and 2.
o Dewatering and grit removal within Train A Aeration Basins 1 and 2 to perform diffuser improvements and structural repair.
o Construction of air piping, pipe supports, and diffuser improvements.
o Builder’s Risk Insurance for 5 years
The total 100% CMAR estimate for this work authorization included herein totaled $8 million, with 310 days to reach substantial completion. The Builder’s Risk Insurance is for the entire project duration.
The Fixed Construction Support Costs and Time Sensitive Construction Support Costs are shown as presented in the original contract awarded in July 2025. The Fixed Support Costs represent the CMARs proposed cost for the total project scope of work estimated to be $300M and the proposed duration of 5 years. The Time Sensitive Construction Support costs are presented here for a 12-month duration to complete the work included in Work Authorization No. 1.
The following table details the costs of the bid work package, CMAR Construction Support Costs, CMAR Contingency, and the CMAR fee.
Major Scope of Work Description - Work Authorization No. 1 Lump Sum Amount
Work Authorization 1 - Train A Diffuser and $7,400,000
Air Piping Improvements Cost of Work
CMAR Fees (8.0% of the Work Package 1 Cost of Work) $592,000
CMAR Contingency for Work Authorization No. 1 $249,000
(based on Risk Register)
Owner Contingency for Work Authorization No. 1 $148,122
(based on Risk Register)
Total Cost of Work plus Fees and Contingency $8,389,122
Fixed Construction Support Costs $8,123,800
(for project estimate cost of $300M and 5-year duration -
one-time authorization
Time Sensitive Construction Support Costs $3,768,424
(12 months for Work Authorization No. 1)
Work Authorization No. 1 $20,281,346
(Sum of Total Cost of Work, CMAR Fees, and
Construction Support Costs)
Attachment A provides the Total Contract Price Summary
FUNDING
Funding in the amount of $20,281,346 to Archer Western Construction, LLC is to be made available utilizing the Regional Wastewater System Extendable Commercial Paper (ECP) Program as the appropriation source. Issuance of ECP notes will occur as cash needs arise.