AGENDA INFORMATION SHEET
DEPARTMENT: Materials Management
ACM: Bryan Langley
AGENDA DATE: December 6, 2016
SUBJECT
Title
Consider adoption of an ordinance authorizing the City Manager to execute a professional services agreement for Pipeline Inspection and Condition Assessment at the Lake Lewisville Water Treatment Plant; providing for the expenditure of funds therefor; and providing an effective date (File 6281-awarded to Pure Technologies U.S. Inc. in an amount not-to-exceed $592,740). The Public Utilities Board recommends approval (6-0).
Body
FILE INFORMATION
The Lake Lewisville Water Treatment Plant, (LLWTP) currently represents approximately 60% of the City's water supply system. The LLWTP is located at the DME/Garland Power and Light complex off of Spencer Road and is supplied with untreated water from a pumping station located on the Hickory Creek arm of Lake Lewisville. The untreated water transmission pipeline system was built in phases with a 27 inch Concrete Cylinder Pipe (CCP) pipeline constructed within a 30 foot wide water pipeline and electric power line easement in 1956-57 and a 30 inch (CCP) pipeline constructed with a Union Pacific Rail Road right of way in 1975.
The 30 inch water line had some recent failures and the quality of the pipe bedding material (native soils were used instead of sand) and installation may be of continued concern. Due to the failure history and the competing use of the Rail/Trail corridor, staff recommends performing a pipeline condition assessment for the 30 inch untreated water transmission pipeline. This project was included in the FY 2016-17 adopted budget. The 27 inch raw water pipe line was properly embedded in sand as specified and found in better condition than the 30 inch pipe line on multiple occasions over the years-including the I-35E widening project in April, 2015. Due to relatively good condition of the 27 inch water line, the staff recommends assessing this pipe condition within the next f...
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