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9.B.
City Council Meeting - FINAL
Meeting Date:
07/15/2014
Co-Submitter:
Brad Hill, Utilities Director
From:
Ryan Roberts, Utilities Engineering Manager

Information

TITLE:

Consideration and Acceptance of Proposal:  Accept the proposal from Aerzen USA Corporation for three (3) High Efficiency Blowers. (Purchase of three blowers for the Wildcat Wastewater Treatment Plant).

RECOMMENDED ACTION:

    Accept the proposal and approve the purchase from Aerzen USA Corporation of Coatesville, PA, for the purchase of (3) three high efficiency "Turbo Blowers" in the amount of $ 692,562.00 plus applicable sales tax. Authorize the City Manager to execute the necessary documents.

Policy Decision or Reason for Action:

The purpose of installing these "turbo blowers" at Wildcat Hill Wastewater Treatment Plant (WWTP) is three (3) fold:  First, these blowers are much more energy efficient and will reduce the City's energy use thereby saving money; Second, the new blowers will allow for better control of the treatment process which will greatly assist in the reduction of nitrogen concentrations, and; Third, because of the de-nitrification benefits, the Arizona Department of Environmental Quality (ADEQ) approved the installation of these blowers within the City's Corrective Action Plan to reduce Total Nitrogen.

Financial Impact:

  • The Utilities Division has budgeted in the Wastewater Treatment Energy Efficiency Project (202-08-375-3204-0-4405) in the amount of $750,000 for FY15.
  • The installation of new high efficiency blowers will reduce annual electrical energy usage by 1,860,000 kWh at the Wildcat Hill WWTP. This will  result in approximately $167,400 dollars per year in annual energy savings for the Utilities Division.

Connection to Council Goal(s) and/or Regional Pla:

Repair replace and maintain infrastructure (Wastewater Aeration Equipment). The aeration blowers are a critical component to the wastewater de-nitrification process and will assist in helping the Wildcat Hill WWTP meet the required regulatory permit levels for nitrogen concentrations. Replacement of the existing inefficient equipment will lower the annual energy costs to the Utilities Division.

Has There Been Previous Council Decision on This:

None previously.

Options and Alternatives:

  1. Accept the proposal and approve the purchase from Aerzen USA Corporation.
  2. Reject all proposals and continue to use the existing aeration blower equipment. By accepting this option, the City may not be able to improve the process de-nitrification, will not lower energy usage and may not comply with the City's Consent Order with ADEQ.
     

Background/History:

Tata & Howard conducted energy audits at the Wildcat Hill WWTP and Rio de Flag Water Reclamation Facility in February of 2012. These audits included an evaluation of the relative wire to air efficiency of the blower systems at both plants. Tests were conducted to evaluate the relative efficiency of the blower systems under normal operating conditions and recording electrical data.

As a result of the energy audit, it was determined that the existing blower systems at the Wildcat Hill WWTP have a wire to air efficiency ranging from 35 percent to 40 percent.  These wire to air efficiencies are well below industry standards for this type of equipment. The audit showed an estimated energy savings of up to 1,860,000 kilowatt hours per year associated with increasing the overall efficiency of the existing blower systems to current industry standards.The report recommended the installation of three new appropriately sized "turbo blowers" and upgrading the process control systems.

Staff solicited a Request for Proposals (RFP) in October/November 2013, only two proposals were received (Aerzen and Neuros). An evaluation committee, consisting of four City staff members and one outside member, evaluated both proposals and found Aerzen to be the highest ranking and most qualified. Aerzen also had the lowest proposal price (Aerzen $692,562; Neuros $928,000).  

Key Considerations:

The Utilities Division conducted a thorough energy audit of both wastewater treatment plants in February 2012. This audit identified several energy conservation measures that will lower annual energy usage and ongoing electrical costs. The energy conservation opportunities were divided into two (2) projects (i.e., Wildcat Hill and Rio) and then prioritized according to the highest payback and rate of return, so Wildcat Hill is being completed first.

Community Involvement:

Inform

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