HomeMy WebLinkAboutAward of Bid to Associated Pool Builders for Filter System at Bogert Pool.pdf Commission Memorandum
REPORT TO: Honorable Mayor and City Commission
FROM: Dan McCarthy, Aquatics Director
Carole Brennan, Recreation Superintendent
Ron Dingman, Parks and Recreation Director
Chuck Winn, Assistant City Manager
SUBJECT: Award of bid to Associated Pool Builders for the replacement of
the filter system at Bogert Pool.
MEETING DATE: April 18, 2011
AGENDA ITEM TYPE: Consent
RECOMMENDATION: Authorize the City Manager to sign the award of bid to Associated
Pool Builders for the replacement of the filter system at Bogert Pool for $98,800.
BACKGROUND: The filtration system currently in place at the Bogert pool is a Vacuum
Dichotomous Earth (DE) system and has been in service since 1939.
The 2008 USAquatics Bogert pool facility survey identified this filtration system as needing
replacement. Below is the recommendation from that report.
2.1 FILTER SYSTEM:
We recommend replacement of the existing vacuum DE system with a high-rate pressure
sand filtration system. Replacement of the filter shall include new filter room piping, new valves,
hair & lint strainer, and new recirculation pump with motor. Upgrade of the electrical systems
may be needed as well. The existing DE tank should remain and be reused as a surge tank for
the recirculation and overflow system of the pool, a recommended replacement cost of $78,000.
USAquatics’ recommendation is based on the fact that Vacuum DE systems are not designed to
handle the amount of particulates outdoor pools experience and the fact that the current system is
72 years old and has lost much of its filtering capacity.
Based on the survey’s recommendation, staff included a new Bogert pool filtration
system in the Capital Improvements Program (CIP) in 2009. In the current FY11 CIP budget,
$78,000 has been budgeted for the replacement of the filtration system.
Staff originally planned to install a High-Rate Pressure Sand (Sand) filtration system as
recommended in the USAquatics survey. Based on new information we are now recommending
installing a Regenerative Media filtration system for the reasons outlined in this memo.
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In November, 2010, staff began putting the Bogert filtration project together, gathering
specifications from qualified companies, for a Sand filtration system.
During our research we spoke with potential distributers and learned that there would be
a minimum 400 gallons per minute (GPM) backwash discharge rate with the Sand system. In
addition to this, the Sand system would require 2 to 4 backwashes per week.
The Vacuum DE filtration system currently used at Bogert pool is discharging at a rate of
100 GPM during backwash, which the existing sewer line is able to accommodate. We are
currently backwashing 2 to 3 times per season.
Staff met with Bob Murray, City Project Engineer II, and Al Rominger, Water/Sewer
Assistant Superintendent, to discuss the filtration project and the backwash discharge rates. Both
Mr. Rominger and Mr. Murray agreed that the existing sewer line servicing the Bogert pool is
not capable of handling the volume of water that the Sand filtration system would generate. It
was also noted that the existing 1 1/2 inch water line would not be able to produce the amount of
water required and would need to be upgraded.
Staff contacted the distributors and explained the capacity restrictions of our sewer line
and water service line. We were told by all distributors we spoke with that it would be extremely
difficult and expensive to achieve a backwash rate of 100 GPM with a Sand Filtration system.
None of the distributers were willing to provide a cost estimate because of the complexity.
Staff then researched alternative solutions and discovered a relatively new filtration system
referred to as a Regenerative Media system. We found that the Regenerative Media system uses
less water, resulting in a discharge rate of less than 100 GPM, provides cleaner water due to a
much finer filter, requires fewer backwashes per year than the Sand system, and require less staff
time than either the DE or Sand system.
Below is a list of the benefits associated with installing a Regenerative Media system and a chart
comparing the water and BTU rates for the Regenerative Media system, the Sand system, and
our current Vacuum DE system.
· The existing sewer line will accommodate the Regenerative Media system
discharge volume of not more than 100 GPM.
· The Regenerative Media system will save approximately 69,000 gallons of water
per season. See table 1
· The existing water service line will supply a sufficient volume of water.
· Installing the Regenerative Media system would result in reductions in water use,
energy use for heating, and pool chemicals.
· Using a Regenerative Media system versus a Sand system will save staff time.
Both the DE and Sand systems require staff to manually change valves. On the
current system staff has to manually brush the filters clean. With the Regenerative
system staff simply turns off the boiler and pushes one button and the filters are
automatically cleaned.
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Table 1
Filter System Type
Backwash
discharge rate
Gallons of water
per backwash
BTU’s per year
to reheat water
Backwashes
per year
Regenerative ≤ 100 gpm 400 gal 0.9 million 2-3
High Pressure Sand 400 gpm 2000 gal 70 million 28-42
Vacuum DE 100 gpm 2000 gal 8 million 2-3
After learning of the sewer and water service line limitations, and fully researching other
filtration systems, staff is recommending purchasing and installing a Regenerative Media
Filtration system at a cost of $98,800. This will include, design (required), filter, piping, high
efficiency pump, and Variable Frequency Drive (VFD).
UNRESOLVED ISSUES: None
ALTERNATIVES: As suggested by the Commission.
FISCAL EFFECTS: As stated above, there is currently $78,000 indentified in the FY11
Recreation CIP Budget for replacement of the Bogert Filtration system. The Regenerative Media
system being recommended will cost $98,800.
Staff is recommending utilizing savings from already completed FY11 Recreation Department
CIP projects to make up the additional $20,800 needed to purchase the Regenerative Filtration
system.
$216,000 was budgeted for the 5 FY11 CIP projects that have been completed. Savings from
these projects total $30,323.46. With the additional $1,398 Energy Rebate from Northwest
Energy the total savings is $31,721.46. Utilizing $20,800 from these savings, in addition to the
budgeted $78,000, to purchase the Regenerative Media system leaves a balance of $10,921.46 in
project savings.
Below is a chart which details the completed projects, amount budgeted for each project, actual
cost upon completion, and amount remaining in each project’s budget.
Table 2
Project Name Actual Budget Actual Cost Savings
Swim Center Automated Chemical Controller $ 12,000.00 $ 8,562.00 $ 3,438.00
Swim Center Natatorium Lighting $ 95,000.00 $ 88,681.00 $ 6,319.00
Swim Center Main Pool Pump $ 85,000.00 $ 74,252.54 $ 10,747.46
Swim Center ADA Chair lift $ 12,000.00 $ 7,106.00 $ 4,894.00
Bogert ADA Chair Lift $ 12,000.00 $ 7,075.00 $ 4,925.00
Northwest Energy Rebate $ 1,398.00
Total $216,000.00 $185,676.54 $ 31,721.46
Attachments: Bid document
Bid tab
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