Regional Water System
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Wylie Water Treatment Plant Conversion to Biologically Active Filtration; Project No. 101-0390-15; Change Order No. 11
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SUBJECT
recommendation
Authorize funding in the amount of $704,669 to RAVA Construction, LLC for Change Order No. 11for replacement of Clearwell 3-2 damaged stop-logs weir wall.
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PURPOSE
During initial startup and testing of a newly constructed weir wall, the wall experienced a partial structural failure. Subsequent structural analysis determined the wall design required major modifications or replacement of the wall to function over full operating range of the system. The District staff and Engineer determined that replacement of the existing stop-log design in favor of a cast-in place wall provided the best long-term solution to maintain proper flow metering of the Wylie WTP III’s effluent for chemical flow pacing and completion of the project.
RECOMMENDATION
The Executive Director, NTMWD staff, and Carollo Engineers, Inc. recommend the Board of Directors authorize a construction change order as follows:
Contractor:
RAVA Construction, LLC
Scope:
Construction Change Order No.11 Project:
101-0390-15, Wylie Water Treatment Plant Conversion to Biologically Active Filtration
Amount:
$704,669 Committee: This will be an item on the November 18, 2026, Water Committee meeting agenda.
DRIVER(S) FOR THIS PROJECT
Strategic Objective: 1.1. High-Quality Services
? Regulatory Compliance ? Asset Condition ? Capacity ? Redundancy/Resiliency
? Relocation or External Requests ? Operational Efficiency ? Safety ? Administrative ? Policy ? Other _____________
BACKGROUND
PROJECT PURPOSE
Improve finished water quality by enhancing the removal of organics and thereby producing water less prone to residual disinfection depletion.
Moderate the flow rate variability through the filters to maintain particulate capture and protect against flow-related turbidity volatility.
Accomp...
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