HomeMy WebLinkAbout9 Water Storage Tank Engineering Contract
AGENDA ITEM #9
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MEETING DATE: August 4, 2021
TO: Board of Directors
FROM: Neil Kaufman, Water System Engineer
SUBJECT: Consideration of Awarding a Contract to Perform Water Storage
Tank Engineering
APPROVED BY______________________________
Brian C. Wright, General Manager
RECOMMENDATION:
Award a contract to Carollo Engineers in the amount of $191,549, plus a ten percent
change order allowance for a total authorization not to exceed $210,700.
BACKGROUND:
The District currently operates 33 water storage tanks located throughout the water
distribution system:
30 ground level welded steel tanks
Two ground level bolted steel tanks
One partially buried pre-stressed concrete tank
The location of these tanks is shown on Figure 1. The tanks range in volume from 100,000
gallons to 1.5 million gallons with the oldest tank constructed in 1963 and the newest tank
constructed in 2005. Other relevant tank data is given in Table 1.
Decade Built Quantity
1960s 1
1970s 21
1980s 4
1990s 5
2000s 2
Total 33
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There are three additional tanks that are currently inactive. A project to replace the Red
Mountain tank is underway and the new tank should be in service during the fall of 2021.
Historically, insufficient attention and funding has been devoted to the maintenance and
upgrade of these storage tanks. Many of these tanks are still utilizing their original interior
coating systems, which are approaching 50 years old. The design standards and seismic
engineering requirements have also changed significantly and many of the tanks do not
meet current standards.
During the preparation of the 2020 Water System Capital Improvement Plan (CIP), the
need for significant enhancements to the District’s water storage tank maintenance
program were identified. The current FY20-21 Water Operating Budget was adopted in the
fall of 2019 and included $114,000 for water storage tank maintenance. This level of
funding is insufficient to address the maintenance needs identified in the 2020 CIP. The
adopted 2020 CIP identified the need for a significant increase in funds for storage tank
maintenance to approximately $800,000 annually. The District developed a water rate
schedule for FY2021-2025, utilizing the updated 2020 Water System CIP and the funding
requirements identified to execute the water storage tank maintenance program. The
FY2021-2025 Water Rate Schedule was presented to the Board and adopted in December
of 2020.
In order to efficiently allocate these water storage tank maintenance funds, the need for an
outside engineering consultant was identified. The consultant would assist the District with
the following:
Seismic Evaluation - Conduct a seismic evaluation of all of the ground level steel
water tanks; identify potential solutions to minimize seismic risk for each tank; and
prepare budget level cost estimates for these potential solutions.
Rehabilitation of Roundhill Tank – The Roundhill Tank was constructed in 1974.
Based on the most recent inspections and maintenance history, it is judged to be
the tank most in need of rehabilitation. The consultant would perform more detailed
evaluations of the Roundhill Tank and then prepare a set of bid documents to
rehabilitate the tank and upgrade it to current standards. The tank evaluation will
include interior and exterior coatings, steel structures, welds, ladders, and other
associated appurtenances.
It is planned that the bid documents developed for the Roundhill Tank will serve as a
template for rehabilitation of the other steel storage tanks built during the 1960s and 1970s.
As noted above there is one partially buried pre-stressed concrete tank (Airport Tank). The
Airport Tank requires repairs to the roof system along with replacement of many of the
interior steel components such as the access ladder and overflow structure. Construction
and rehabilitation of pre-stressed concrete tanks utilizes a design-build approach with the
engineering performed by the contractor performing the work. There are only a few
contractors nationwide with the experience and capability to this perform this work and a
recommendation for the Airport Tank will be presented to the Board separately.
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In June 2021, the Water Department issued a Request for Proposals (RFP) to select a
consultant to perform the engineering work. Three proposals were received in response to
the RFP:
Carollo Engineers – Reno, NV
Harper & Associates – Corona, CA
TJC and Associates – Sacramento, CA
A staff review committee was selected and the proposals were evaluated based on the
following criteria:
Proposed scope of work and project methodology (30%)
Experience of the firm with similar projects (15%)
Experience of project team with similar projects (20%)
The firm’s procedures, methodology and quality assurance/quality control (5%)
References (10%)
Cost (20%)
After completion of the technical review, the proposals from Carollo was judged to be the
most favorable, followed by TJC and then Harper.
Technical Scoring
Firm Rank
Carollo Engineers 1
TJC and Associates 2
Harper & Associates 3
The proposed costs were then reviewed. The overall cost proposals from the three firms
ranged from approximately $191,000 to $292,000. The Carollo proposal presented the
lowest overall cost.
Further review of the proposals identified the following:
Harper had significantly more effort than Carollo and TJC devoted to the seismic
evaluation. This level of effort is beyond what was anticipated in the RFP.
TJC had significantly more effort devoted to the construction inspection of Roundhill
Tank than Carollo and Harper. The actual level of construction inspection required
for the tank rehabilitation is dependent on the final scope of work being undertaken
and the quality of the contractor. In reality, the effort defined by TJC is probably an
upper limit with Carollo and Harper on the low end of the scale.
Overall, it was determined that the Carollo approach would better serve the District. There
is sufficient effort for the seismic evaluation and Roundhill Tank engineering. It is possible
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that additional field inspection would be required beyond what is currently listed in the
proposal, but the overall costs for Carollo should remain below that of the other two firms.
Cost Scoring
Firm Rank
Carollo Engineers 1
TJC and Associates 2
Harper & Associates 3
Finally, an aggregated ranking (technical & cost) of the proposers was developed:
Overall Scoring
Firm Overall Rank
Carollo Engineers 1
TJC and Associates 2
Harper & Associates 3
Therefore, it is recommended that the contract be awarded to Carollo Engineers.
The planned project schedule is given below.
August 4, 2021 – Award Engineering Contract to Consultant
August & September 2021 – Perform Seismic Evaluations
October & November 2021 – Prepare Bid Documents for Roundhill Tank
December 2021 – Begin Advertising for Bids for Roundhill Tank Rehabilitation
January 2022 – Bid Opening for Roundhill Tank Rehabilitation
February 2022 – Award Contract for Roundhill Tank Rehabilitation
May 1, 2022 – Begin Roundhill Tank Rehabilitation
Late June 2022 – Roundhill Tank In Service
It is anticipated that rehabilitation of the Roundhill Tank will be declared categorically
exempt under CEQA. Once a firm construction schedule has been established, the District
will contact the adjoining property owners to inform them of this upcoming project.
FISCAL IMPACT:
The Board approved FY2021 Water Capital Expenditures Budget included $115,500 for
the maintenance of water storage tanks. The cost proposal for the requested engineering
consulting services from Carollo is $191,549. A ten percent change order allowance is
recommended for a total authorization not to exceed $210,700.
An additional expense of $96,700 required to fund the engineering consulting services
needed in preparation for the District’s Water Storage Tank Maintenance Program.
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The Board Adopted Budget (AB) in fall of 2019 included Water 2021 Capital Expenditures
of $2,009,000. This budget did not include the pipeline replacement project (approved
4/2021) and assumed an annual water rate increase of 3%. However, the approved 10-
year water capital infrastructure replacement study includes pipeline replacements for
FY2021 and the recently approved water rate schedule includes an increase of
approximately 9% for FY 2021 to fund the additional capital expenses.
Water 2021 Capital Expenditures Forecast for 2021 is $3.1M, for a variance to AB of
$1,091,000. The funding source for this project is rates. The water rates increase for 2021
generates and estimated incremental $770,000 and savings in Water SCADA and Facility
Metering projects for 2021 compared to AB are estimated at $200,000, combining for a
total of $970,000. The remaining gap of up to $121,000 (assuming 100% of contingency of
$113k utilized) would be funded from operating reserves balance.
Sufficient funds exist in the $3.1 million capital expenditure Forecast 2021 to absorb the
additional $96,700 capital expenditure.
ATTACHMENTS:
Figure 1 – Water Storage Tank Locations
Table 1 – Water Storage Tank Data