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TO: Mayor Richard C. Irvin
FROM: Jason Bauer, P.E., Assistant Director of Public Works/Assistant City Engineer
DATE: May 6, 2021
SUBJECT:
A resolution authorizing the Director of Purchasing to execute a contract with Crawford, Murphy and Tilly, Aurora, IL, in the amount of $90,400 for water main flushing.
PURPOSE:
To maintain water main quality throughout the water distribution system.
BACKGROUND:
Regular maintenance of the water distribution system is necessary to keep the system working well. One component of the maintenance program is water main flushing.
The velocity of the water flowing through most water mains is usually slow, therefore as time passes any solids in the water tend to settle at the bottom of the pipe. Though harmless, these solids can be stirred up when there is an increase in flow velocity from events such as main breaks or hydrant use.
Crawford Murphy and Tilly (CMT) previously developed a computer model of the City's distribution system that is utilized for various purposes including identification of the necessary valve closures to produce the flow rates required to remove sediment from the mains. Due to their knowledge of the computer model, CMT is uniquely qualified to provide direction to city employees during the flushing operation.
This contract, which is attached as Exhibit 1, will provide for the services of one staff member from CMT to direct the program. The remaining 4-6 team members required each day will come from the Water and Sewer Maintenance and Engineering Divisions. It is estimated that during the three months that the flushing is ongoing, approximately 20% of the system will be flushed, those areas are shown on page 6 of the exhibit.
DISCUSSION:
No flushing was completed in 2020 and only $25,000 was budgeted requested for 2021 (in account 510-4063-511-38-68), to reduce the water maintenance operational budget. Due to some COVID-19 relief of fees for other programs that would normally be due...
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