HomeMy WebLinkAbout06-21-2016 Item 10 Water Resource Recovery Facility Aeration Blower Replacement Project Spec 91448
Meeting Date: 6/21/2016
FROM: Carrie Mattingly, Utilities Director
Prepared By: Dave Hix, Utilities Deputy Director – Wastewater
Howard Brewen, Water Resource Recovery Facility Supervisor
SUBJECT: WATER RESOURCE RECOVERY FACILITY AERATION BLOWER
REPLACEMENT PROJECT-SPECIFICATION NO. 91448
RECOMMENDATION
1. Authorize staff to advertise a Request for Proposals (RFP) for aeration blower
replacement for the Water Resource Recovery Facility, Specification No. 91448; and
2. Authorize the City Manager to award the contract if the lowest proposal is within the
engineer’s estimate of $320,000.
DISCUSSION
Background
The aeration bays (A-bays) were identified as one of the processes that were most affected by the
new National Pollutant Discharge Elimination System (NPDES) permit requirements that went
into effect December 2015. The A-bays are needed for the biological process that converts the
toxic ammonia found in wastewater to non-harmful nitrogen. This process requires that three
major disciplines (mechanical, biological, and chemical) work together in a complex manner to
achieve the desired outcome. The mechanical discipline consists of aeration blowers that are a
critical component for process control and in meeting regulatory requirements for the WRRF.
There are two existing aeration blowers in operation that are 20 years old, operate continuously
and have been rebuilt numerous times. The recently completed WRRF Facility Plan includes an
analysis of the aeration blower system and concludes that the aeration blowers are at high risk for
failure and replacement should not wait for the WRRF Project to commence.
Because the A-bays are undergoing a major transformation in the WRRF Project, the number
and size of aeration blowers required will be significantly different from the present.
Accordingly, Water Systems Consultants (WSC) was retained to find the best solution for
purchasing aeration blowers that could be redeployed in the future WRRF Project. The findings
concluded that one aeration blower that was sized larger would meet present demands and could
be integrated into the new aeration blower system included in the WRRF Project.
FISCAL IMPACT
The replacement of two aeration blowers (smaller than the one proposed here) were identified in
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the 2013-15 Capital Improvement Plan for WRRF Facility Major Maintenance page 3-169.
$175,000 was identified in 2014-15 and $175,000 in 2015-16 for a total of $350,000 available
for this project. The engineer’s estimate for the replacement is $320,000. The total available
balance of the major maintenance account is $559,677.
ALTERNATIVE
The City Council may choose to deny or defer the approval to advertise this project. Should this
be Council’s choice, the existing aeration blowers, which have been identified as having a high
risk of failure, would continue to be rebuilt if possible or catastrophically fail. Given the critical
nature of oxygen to the biological process, failure could result in water quality violations and
potential fines.
Attachments:
a - Council Reading File - RFP 91280 WRRF Aeration Blower Replacement Project
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