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TO: Mayor Richard C. Irvin
FROM: Mark Phipps, Professional Engineer
DATE: February 26, 2018
SUBJECT:
Resolution to approve a professional services agreement with Crawford, Murphy & Tilly, Inc. in the amount of $343,900.00 for the 2018 Water Main Flushing Program.
PURPOSE:
To continue providing high quality water to the City's water customers.
BACKGROUND:
Regular maintenance of the water distribution system is necessary to keep the system working well. One standard maintenance activity is a system-wide water main flushing program.
Because water mains are sized to handle fire-fighting flows, which may be several times larger than domestic and commercial water use needs, the velocity of flow through water mains is normally fairly low. Low velocity flow allows solids to settle on the bottom of pipes. These deposits can be a source of color, taste, or odor when they are stirred up by short-term increases in flow, such as water main breaks or hydrant flow testing by the Fire Department. Implementing a City-wide, planned and organized flushing program allows the deposits that settle in the bottom of a pipe to be removed from the water distribution network systematically.
Crawford, Murphy & Tilly, Inc. (CMT) developed a computer model of the City's Water Production Plant and water distribution system in the 1990's. They have updated the model periodically and are nearly finished with an update that began in 2017. CMT uses the model to determine which valves need to be closed in sequence to produce flow velocities high enough to flush deposits from the water distribution network. Each summer, in a designated section of the City's water distribution system, CMT staff operates valves and hydrants, tests water quality, adjusts the computer model, posts informational signage, and works around the schedules of critical water users. The City began planning its system-wide water main flushing program in 2012. Flushing began with Area 1 in 2013. By 2016 the first system-wide flushing program had been completed. The 2018 Water Main Flushing Program will be the second year of the second cycle through the program.
DISCUSSION:
Exhibit A in the attached professional services agreement identifies the areas planned for water main flushing in 2018 as Area 2 (shown in orange) and three sub-areas of Area 3, namely Zones 3C, 3D, and 3F (shown in red). Exhibit B shows those areas on a map.
Account 510-4063-511.38-68 has sufficient funds for this project.
IMPACT STATEMENT:
Customers may experience fluctuating water pressure and some water discoloration while their water main is being flushed. If these disruptions occur, they will typically be limited to a few hours during the work day. Customers in and near the project area will be notified in advance of the flushing program using multiple forms of communication. Informational flyers will be mailed in May, before the start of the program. Signs will be placed along prominent streets a few days before flushing begins in each neighborhood. Both the flyer and the signs will direct customers to call a hotline with a recorded message updated at the end of each work day. The message describes the locations where water mains will be flushed the next day in both English and Spanish.
Traffic may be affected by short-term lane closures near open fire hydrants.
RECOMMENDATIONS:
Staff recommends the proposed resolution be adopted.
cc: Alderman Garza, Chairman
Alderman Donnell
Alderman Bohman
Alderman Hart-Burns, Alternate
CITY OF AURORA, ILLINOIS
RESOLUTION NO. _________
DATE OF PASSAGE ________________
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A Resolution approving a professional services agreement with Crawford, Murphy & Tilly, Inc. in the amount of $343,900.00 for the 2018 Water Main Flushing Program.
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WHEREAS, the City of Aurora has a population of more than 25,000 persons and is, therefore, a home rule unit under subsection (a) of Section 6 of Article VII of the Illinois Constitution of 1970; and
WHEREAS, subject to said Section, a home rule unit may exercise any power and perform any function pertaining to its government and affairs for the protection of the public health, safety, morals, and welfare; and
WHEREAS, regular maintenance of the water distribution network is necessary to continue providing high quality water to the City's water customers; and
WHEREAS, a water main flushing program is part of the City's maintenance of its water distribution network; and
WHEREAS, account 510-4063-511.38-68 has sufficient funds for this project)
NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Aurora, Illinois, as follows: a professional services agreement with Crawford, Murphy & Tilly, Inc. in the amount of $343,900.00 for the 2018 Water Main Flushing Program is hereby approved, and the Director of Purchasing is hereby authorized to enter into such a contract on behalf of the City.