Commission to consider $2.26 million agreement for water plant upgrades

On Tuesday, the City Commission will consider a $2.268 million professional services agreement with Advanced Engineering and Environmental Services, Inc. for filtration improvements at the water treatment plant.

The project will replace the filter media and associated under drains of all 16 water treatment plant filter bays. Filter cleaning implements and filter waste water solutions will also be addressed, according to the staff report. The project also includes “plant optimization plans and personnel coaching” as well as updated and integrated software controls to monitor and report plant data, according to the staff report.

Elevated levels of haloacetic acids again detected in city water; plant upgrades expected to reduce the levels

The city received two proposals for the project and they were evaluated by a six-member committee. AE2S was the high scoring proposal and staff is recommending approval of the agreement.

This project is being funded through the city’s water capital improvement fund.

Filters at the water treatment plant have been under investigation for the last decade, according to the staff report.

In 2010, staff noticed a decline in filter performance and AE2S performed a filter media evaluation as an first step in identifying potential contributing factors. The evaluation found that the filter media had degraded and the city should consider replacement, according to the staff report.

In 2012, the city hired AE2S to complete a filtration process evaluation, which “concluded that to improve filter performance, replacement of the entire depth of the filter media in conjunction with new under drains, and an air back wash system, was needed,” according to the staff report.

Those reports were the basis for drafting the agreement and scope work being recommended for commission approval on Tuesday.

According to the staff report, if approved, AE2S will:

  • provide clarification optimization recommendations and strategies for minimizing disinfection byproduct, HAA5, formation;
    • performance coaching by technical experts
  • Design phase services, consisting of:
    • Securing necessary permits from the Montana Department of Environmental Quality and the City of Great Falls;
    • replacing the filter media to improve filter performance;
    • looking at options for renovating the existing filter basins and assessing their structural integrity;
    • replacing the filter beds and adding air scour while maintaining provisions for surface wash;
    • replacing the filter under drain system with the latest LEOPOLD Technology;
    • adding filter to waste provisions to the 1932 and 1952 filter sections (8 filters);
    • replacing the filter backwash flow meter;
    • providing a supplemental backwash water supply pipeline to the end of the 1959 filter section;
    • constructing filter to waste effluent piping and related improvements (de-chlorination and water quantity/quality monitoring equipment) to discharge low solids water to the Missouri River via the existing storm main;
    • determining if the storm main can be used for a plant outfall and if so, verification of necessary permitting: a separate building will be required to house the de-chlorination and metering equipment;
    • geotechnical and permitting services for any new building(s);
    • reviewing the existing operational data recording and reporting system to identify potential changes that would make it more convenient to obtain and evaluate key operational data generated by WTP instrumentation; adding instrumentation and modifying the controls system accordingly;
    • optimizing/improving the clarification process to achieve a clarified effluent turbidity of less than 1 nephelometric turbidity unit (NTU);
    • pending implementation of recommended improvements to the filters, reviewing the performance of the backwash wastewater treatment system and consideration of increasing the storage volume of pumping system capacity to eliminate concerns regarding the volume of waste water generated during the backwash process;
    • designing of temporary work sites and connections;
    • submission of bid documents at 30 percent, 60 percent and 90 percent for review and comment by the City, and final bid documents. Each submission will include an opinion of probable construction cost;
    • conducting two milestone meetings at 60 percent and 90 percent with the city;
    • automating the filter backwash control tables with an option for manual control and tying them into the existing uninterruptable power supply backup;
    • performing a risk assessment for the project using three construction phases and assist in determining risks of each phase before and during construction, and suggested management strategies;
    • providing operator training to city staff;
    • preparing the bid-ready plans, specifications, and estimates for each of the three separate construction phases;
    • determining the wage rate classification;
    • completing hazardous materials testing and permitting where needed;
    • preparation of a schedule of project progress, submittals and values.
  • Construction Services – the construction work for each phase.
  • Instrumentation and controls programming, startup and support.