Cotati City Council
Agenda Staff Report
Item type: CONSENT CALENDAR (ACTION)
To: City Council
Subject: Main Flushing and Water Treatment Services for the Water Distribution System Date: October 25, 2022
Written by: Craig Scott, Director of Public Works/City Engineer Recommendation
It is recommended the City of Cotati City Council by motion approve a Standard Service Agreement with No-Des, Inc. to provide main flushing services for a 2-week period Background
The City owns and operates a public drinking water system and is regulated by the State Water Resources Control Board. Proper maintenance of the water system requires regular flushing of the distribution system and particularly the pipelines with low points and dead ends. The flushing maintains water clarity and discharges sediment that may collect in the system.
Analysis/Discussion
With the increased frequency and severity of droughts, and the current multi-year drought, owners and operators of public water systems are increasingly using closed system flushing techniques, instead of flushing water, to conserve water. The City used the closed system technique in 2016 and is again proposing its use.
The closed system flushing method consists of hiring a service which provides a trailer mounted water filtration system, real time water quality measurement and pumping equipment to draw water from one hydrant, treat the water, and return the treated water to the system. The filters remove sediment which is not harmful to customers but does lead to discoloration and has the potential to clog water meters.
The City has researched providers of this service and have only found the one provider, No-Des, Inc. City Staff requested and No-Des, Inc. provided a quote to provide the treatment trailer, replacement filters, appurtenant equipment including hoses and fittings, and a crew of two for approximately a two-week period. The process begins with “burndown” of the equipment which sanitizes the trailer mounted equipment prior to use, then the flushing operation including moving from one location to another, and replacement filters. City Staff has identified areas of town for this treatment and it would cover approximately one-third of the distribution system or approximately seven miles of pipeline.
Financial Considerations
The City’s adopted FY22/23 Budget includes $60,000 for main flushing contract services which was based on a prior quote received in 2021. The updated quote for services attached from NoDes, Inc. is for an amount of $69,648. Therefore, Staff is proposing reclassifying the required $9,650 of additional funds required from the water operation fund’s repairs & maintenance account. No budgetary adjustments or actions are required from the City Council at this time.
Environmental Issues
This action is exempt from the California Environmental Quality Act (CEQA) because it is not a project which has a potential for resulting in either a direct physical change in the environment, or a reasonably foreseeable indirect physical change in the environment, pursuant to CEQA Guideline section 15378.
Attachments:
City of Cotati No-Des Contract Operations Flushing Quote (PDF)