HomeMy WebLinkAbout12-16-19 City Commission Packet Materials - C9. TO 9 of the PSMTO with AE2S for Engineering Services for Sourdough Reservoir
Commission Memorandum
REPORT TO: Honorable Mayor and City Commission
FROM: Brian Heaston, Senior Engineer
Mitch Reister, Director of Public Works
SUBJECT: Authorize the City Manager to execute Task Order No. 9 of the Professional
Services Master Task Order Agreement with the firm of AE2S, Inc. providing professional engineering services for the Bozeman Sourdough & Lyman Reservoir Inspection and Evaluation
project.
MEETING DATE: December 16, 2019
AGENDA ITEM TYPE: Consent
RECOMMENDATION: Authorize the City Manager to execute Task Order No. 9 of the
Professional Services Master Task Order Agreement with the firm of AE2S, Inc. providing
professional engineering services for the Bozeman Sourdough & Lyman Reservoir Inspection and Evaluation project.
BACKGROUND: AE2S, Inc. provides professional engineering services on as on call basis for
the Bozeman Water Treatment Plant facility (WTP) under a Master Task Order Agreement
entered into on April 24, 2017. Task Order No. 9 attached provides professional engineering services for the Bozeman Sourdough & Lyman Reservoir Inspection and Evaluation project.
Under this task order agreement, AE2S will hire and manage wet inspection services to collect
data necessary to produce a report documenting inspection findings and conclusions along with
recommendations and cost estimates for tank rehabilitation activities.
Sourdough Tank was completed and brought into service in 1957. It is a partially buried 4
million gallon concrete potable water storage tank fed by the Sourdough Water Treatment Plant.
Exterior concrete rehabilitation was completed in the mid 2000’s. Interior concrete rehabilitation
has not occurred over the life of tank and is likely needed it has been in continuous service for 62
years. Prior wet inspections of the tank interior have found evidence of concrete deterioration. A more intensive wet inspection will occur under Task Order No. 9 to accurately identify
location and extent of concrete deteriorations as well as condition assessment of other interior
tank elements such as the tank inlet/outlet and overflow pipes. Inspection findings will inform
recommendations and associated cost estimates for interior tank rehabilitation activities.
Lyman Tank was originally completed and brought into service in the late 1880’s and is fed by
Lyman Spring. Its original configuration was expanded over time to its current 5.3 million
154
gallon capacity. Much of the original concrete work, now approximately 130 years old, remains
integral to the tank. A major rehabilitation consisting of concrete spot repairs, plastic liner
installation, and construction of a roof was completed in 2004. The liner has not performed
adequately since its installation and leaks at a rate upwards of 100 gallons per minute. Findings and conclusions of the wet inspection will inform recommendations and associated cost
estimates for rehabilitation activities to stem liner leakage or perhaps even call for full capital
replacement of the Lyman Tank given its age and condition.
FISCAL EFFECTS: The approved FY20 Water Fund CIP contains project W84, funded at $600,000, for Sourdough Tank Inspection & Improvements. Task Order No. 9 contains a
negotiated fee not to exceed $46,872 which includes scope to inspect both Sourdough and
Lyman tanks. After debiting Task Order No. 9 from the W84 funding allocation, an unobligated
project fund balance of $553,128 remains for design and construction of Sourdough Tank
rehabilitation improvements.
Lyman Tank inspection is included as both a matter of convenience and necessity given the age
of Lyman Tank and the specialized skills and equipment necessary to perform wet inspection of
potable water storage facilities. Inspection findings and conclusions for Lyman Tank will
provide information necessary to inform if full capital replacement, currently scheduled in FY21 Water Fund CIP as project W88 at $10mln, can be delayed by a less expensive rehabilitation
project or should be undertaken as currently planned in the CIP.
ALTERNATIVES: As suggested by the Commission
ATTACHMENTS: Task Order No. 9
Hyperlinked: Professional Services Master Task Order Agreement
Report compiled on December 5, 2019
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