Title
Staff Report to Approve a Sole Source Purchase by the Water Pollution Control Plant (WPCP) of One Thousand Aeration Basin Fine-Bubble Membrane Diffusers from Evoqua Water Technologies for an Amount Not to Exceed $86,000
Staffreport
SUMMARY AND RECOMMENDATIONS
The WPCP needs to replace 1,000 existing diffusers in the aeration basins due to degradation of the existing diffusers that is creating a loss of aeration efficiency.
Staff recommends City Council adopt a Resolution making a finding under California Public Contract Code section 3400(c)(3) that a sole-source Purchase Order not to exceed $86,000 is appropriate to provide 1,000 replacement bubble diffusers.
Staff recommends a sole source Purchase Order because there is only one U.S. vendor that sells this particular style diffuser.
BACKGROUND
The WPCP had fine-bubble membrane diffusers installed in one aeration basin in 1990 and in the second aeration basin in 2002. Typically, membrane diffusers have a nominal 10-year life span.
During the last few years, the WPCP has been seeing spikes in influent loading which has led to two aeration blowers being on simultaneously to maintain adequate oxygen levels. During warm months, this can be an almost daily occurrence. This frequent increase in airflow has led to the rapid degradation of the existing membrane diffusers, which have also existed well beyond their typical life span.
Analysis
Due to the age of the aeration system, there is only one U.S. vendor that can still provide replacement diffusers. Purchasing a different type of diffuser would require a capital improvement project involving the design and engineering of a completely different air delivery system and replacing all existing piping. In 2002, the installation of the existing system for one basin cost $350,000; the anticipated cost would be much greater today.
The WPCP currently needs to replace diffusers in both basins. Purchasing replacement diffusers for our system while they are ...
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