HomeMy WebLinkAbout2.b. Presentation of Peer Review 1.5 Million Gallon Ground Storage Reservoir and Booster StationI:\City Clerk\Agenda Items\Approved Items\2.b. Presentation of Peer Review 1.5 Million Gallon Ground Storage Reservoir and Booster Station.docx
EXECUTIVE SUMMARY
City Council Work Session: May 9, 2016
AGENDA ITEM: Presentation of Peer Review 1.5 Million
Gallon Ground Storage Reservoir and
Booster Station, Engineering Project 179
AGENDA SECTION:
Discussion
PREPARED BY: Patrick Wrase, PE, Director of Public
Works / City Engineer AGENDA NO. 2.b.
ATTACHMENTS: SEH, Inc. Peer Review Proposal and
Peer Review Memorandum APPROVED BY: ddj
RECOMMENDED ACTIONS: Discussion
BACKGROUND:
On September 1, 2015, the Rosemount City Council authorized a Professional Services contract with WSB
and Associates, Inc. (WSB) to provide design, construction management and startup services for the 1.5
Million Gallon Ground Storage Reservoir and Booster Station. At the December 15, 2015 meeting the
Council received the plans and specifications and authorized the advertisement for bids for the project,
with bids scheduled to be received on January 21, 2016. Shortly thereafter, revised construction cost
estimates provided by WSB indicated that the anticipated cost of the project had increased from
$4,138,000 projected in the April 29, 2015 “Rosemount Water Supply and Storage Capacity Evaluation” to
$6,028,281. With the large increase in cost, the Council was presented a project update at the work session
held on January 5, 2016. The Council was concerned with the cost increase but allowed the bid opening
for the project to proceed. Subsequently, the Council directed staff to seek a Peer Review of the WSB
design. The purpose of the Peer Review was to confirm the design assumptions and calculations for the
tank and to determine if any cost savings measures could be introduced to reduce the cost of the project.
Staff initially contacted CH2M Hill to discuss the project and to solicit a proposal to prepare the Peer
Review. CH2M Hill staff considered the request but declined the opportunity. Staff then recommended
that SEH, Inc. be retained to perform the Peer Review due to their water utility qualifications and recent
experience working in Rosemount with the East Side Utilities Study. An Agreement with SEH to perform
the Peer Review was approved January 29, 2016. The SEH services were to document: 1) the need for the
project; 2) timing of the project; 3) appropriateness of the type of storage; 4) appropriateness of the
storage location; and 5) opportunities for cost savings.
SEH has met with city Staff and WSB representatives on several occasions since beginning the review
effort. SEH staff has reviewed numerous city and WSB documents related to the project and has
examined the project history, design calculations and design assumptions in detail and has now completed
the peer review document. SEH has determined that mainly due to the a slower development pace in the
UMORE area and partially due to enhanced safety factors in the WSB design calculations, the need for the
tank is notably further into the future than as determined last April. Additionally, SEH has identified
several potential cost savings measures related to the current design but also for alternative storage and
2
water treatment strategies that could further reduce the cost of the overall Rosemount water system.
Additionally, since the time the 1.5MG reservoir project was set into motion, new questions have emerged
regarding Manganese Health Risk Limits set by the Minnesota Department of Health, softening
considerations and the potential benefit to chloride reduction in receiving waters and providing a uniform
water quality throughout the City of Rosemount system. In addition to the existing radium concentration
in a few of the Rosemount wells these additional water quality issues warrant the need for an examination
of the water treatment needs of the city.
Bids for the project were opened on February 5, 2016 with bids ranging from $5.1 to $7.4 million. The
Council preferred, fully buried tank project, resulted in a low bid offer of $5.4 million. Including
Engineering, Legal, and Administrative costs, the total estimate at completion for the as bid project is
$5,623,891, approximately 36% greater than the preliminary estimate from April 2015. The bid documents
required the bidders to guarantee submitted bids for 120 days from the opening date. The submitted bids
will therefore expire on June 5, 2016.
Staff recommends that due to the Peer Review findings, the implementation of the 1.5 Million Gallon
Ground Storage Reservoir and Booster Station be delayed and that bids are rejected. It is intended to
conduct a water facilities planning study to determine the most appropriate course of action with respect
to both storage and treatment. If the best course includes a ground storage reservoir, the plans can be
resurrected and implemented at a future date, possibly in coordination with the Rosemount Northwest
Water treatment plant.
SUMMARY:
The results of the Peer Analysis of the 1.5MG Reservoir and Booster Station is complete and a discussion
is required to determine the most appropriate plan for moving forward. Staff recommends that due to the
Peer Review findings, the implementation of the 1.5 Million Gallon Ground Storage Reservoir and
Booster Station be delayed and that bids be rejected.
March 5, 2016 RE: Peer Review of 1.5 MG Ground Storage
Reservoir and Booster Station Project
City of Rosemount, Minnesota
City Project No. ENG 179
SEH No. ROSEM 136006
Mr. Patrick Wrase, PE
Public Works Director/City Engineer
2875 145th Street West
Rosemount, MN 55068
Dear Pat:
We are pleased to present to you is draft memorandum on our peer review of the City’s proposed 1.5 MG
Ground Storage Reservoir and Booster Station (GSR) Project. The purpose of the peer review is to help
the City to develop answers to the questions of:
1. Verification of need for the GSR Project
2. Appropriateness of the timing for execution of the GSR Project.
3. Appropriateness for the type of storage selected for the proposed project.
4. Appropriateness of the location selected for the proposed project.
5. Opportunities for cost savings associated with the project.
Using a collection of the City’s past water system planning document as well as information collected from
meetings with City staff and folks from WSB, Inc., this memorandum provides analyses and discussions
on community growth, and associated water demands as they relate to the schedule for when the GSR
facility might be needed. This memorandum also provides discussion on the results of several different
water system modeling scenarios that simulate use of the GSR facilities. Finally, this memorandum
provides discussion on potential cost savings associated with water storage and the GSR project.
It has been our pleasure to assist the City of Rosemount with this peer review and we want to thank City
Staff and WSB, Inc., for the time and energy put forth in helping us to complete our review. As always, it
is very important to us our services continue to meet and surpass your needs and expectations. After you
have had an opportunity to review this memorandum, we would like to hear any comments, concerns or
questions you may have. We would be pleased to discuss the contents this memorandum with you and
any other interested parties at a mutually convenient time. We look forward to serving the City of
Rosemount in the future.
Sincerely,
SHORT ELLIOTT HENDRICKSON INC.
Miles B. Jensen, PE
Principal | Regional Practice Center Leader
ah
Enclosure or Attachment
s:\pt\r\rosem\136006\4-prelim-dsgn-rpts\seh gsr peer review memorandum transmittal letter.docx
Short Elliott Hendrickson Inc. | 3535 Vadnais Center Drive | Saint Paul, MN 55110-5196
SEH is an equal opportunity employer | www.sehinc.com | 651.490.2000 | 800.325.2055 | 888.908.8166 fax
Engineers | Architects | Planners | Scientists
Short Elliott Hendrickson Inc., 3535 Vadnais Center Drive, St. Paul, MN 55110-5196
SEH is 100% employee-owned | sehinc.com | 651.490.2000 | 800.325.2055 | 888.908.8166 fax
MEMORANDUM
TO: Patrick Wrase, PE
FROM: Miles B. Jensen, PE, Mark Wallis, PE
DATE: May 3, 2016
RE: West Zone Supply - Storage Review
SEH No. ROSEM 136006 14.00
Pat:
As requested, we have completed an engineering review of the proposed 1.5 million gallon (MG) Ground
Storage Reservoir and Booster Station (GSR) project. The impetus for our review came in December
2015. With the GSR project out for bids, Staff and Council developed concerns for the GSR project due to
estimated project cost and a perceived delay in the schedule for the UMore property development.
Because of these concerns, the City of Rosemount requested a peer review assessment of the GSR
project be made to help answer questions of:
1. Verification of need for the GSR Project
2. Appropriateness of the timing for execution of the GSR Project.
3. Appropriateness for the type of storage selected for the proposed project.
4. Appropriateness of the location selected for the proposed project.
5. Opportunities for cost savings associated with the project.
In performing this work, we attended several meetings with City Staff and engineers from WSB &
Associates, Inc. to discuss various aspects of the project. It was through these discussions that we were
able to develop an understanding for the considerations and design parameters that went into the
conceptual planning and subsequent design phases of the project. We appreciate the time and energy
put forth by all parties in helping us to complete our review.
Through our meeting participation and review of the City’s previous water system planning documents, it
is understood that the City’s rate of development is now moving at a slower pace than in the years of
recent past. To rephrase, it is with the advance of time that has allowed us to apply more current
information on land development, water demands and costs to the GSR project that began in the planning
stages many years earlier, under different development conditions.
As of this writing, bids for the GSR project have been received with the costs ranging between $5.1M and
$5.5M depending on the alternate(s) selected. From our analyses, we understand the bid GSR project
represents a viable solution for providing additional water storage to the Rosemount system. However,
by applying our understanding of current land development and water demand trends, the findings of our
review allows us to conclude that the City can hold off on construction of the proposed GSR project for
several years. This delay in project schedule will then allow time for the City to revisit the project design
and potential cost savings opportunities.
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 2
BACKGROUND
In January 2015, a memorandum was prepared by the City that identified a need for additional water
system storage based upon the equivalent number of homes in approved preliminary plats and the
perceived schedule for development of the UMore property. The memorandum noted that an additional
1.5 million gallons (MG) of additional storage was necessary to allow the City to provide adequate water
supply and fire flow capacity to cover the City’s [then] current population, plus the population attributable
to the approved preliminary plats as well as Phases 1 through 5 of the UMore Development.
In April 2015, a memorandum was prepared that provided an evaluation for the type of storage,
comparing the construction and life cycle costs associated with elevated (water tower) storage and
ground storage with booster pumps (GSR) and concluded that the GSR project was the least cost option
for the City. The memorandum further recommended that the proposed GSR be located directly adjacent
to the Bacardi Water Tower. This recommended location is consistent with the City’s August 2007
Comprehensive Water System Plan and, according to an August 2014 memorandum, could provide the
benefit of mixing water from Wells 14, 15 and 16 to comply, if needed, with the combined radium
standard, prior to introduction of the water into the City’s distribution system. The recommended tank site
is also the proposed site of a future water treatment plant (WTP). The April 2015 memorandum noted
that recommended GSR design could also serve as a clearwell for the proposed WTP.
PROJECT DESCRIPTION
The scope of this project was to provide an engineering review of the City’s proposed GSR Project. This
work included a review of pertinent planning documents, some water system modeling, and a review of
the GSR bidding documents, in addition to meeting with City staff and the GSR design engineer to
assemble information that will help the City develop answers to the five (5) basic questions noted above.
Our work does not attempt to re-design the entire West Side and East Side water system and
comprehensive plans. The primary purpose of this Technical Memo is to provide City staff and Council
background and context into the design decisions that must be made relating to the timing, location, and
style of storage facilities required to serve development. Supporting documents can be found in the
attachment at the end of this memo. Our analysis consists of three components:
Water System Planning Review: compare previous planning documents to current development
trends to update the discussion of the need/timing of additional storage, and to compare the style of
storage facility proposed to alternative storage facilities.
Water System Modeling Review: compare operation of the proposed facility to alternative storage
styles and locations – to determine the need/timing of additional storage and appropriate location for
storage to meet both near term and ultimate system needs.
GSR Bid Document Review and Site Planning: review GSR bids and attempt to identify potential
cost saving measures, and review the GSR project in light of a potential future water treatment facility
on this site.
EXECUTIVE SUMMARY
The following summary is formatted to provide information associated with the five (5) questions of:
1. Verification of need for the GSR Project
2. Appropriateness of the timing for execution of the GSR Project.
3. Appropriateness for the type of storage selected for the proposed project.
4. Appropriateness of the location selected for the proposed project.
5. Opportunities for cost savings associated with the project.
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 3
The findings of our review conclude that the proposed GSR project does not appear to be needed for
several years and the City could use the apparent schedule delay to review cost-saving options for its
water storage program.
Question #1: Verification of Need
The following conclusions and notations are offered:
According to our Water Demand and Supply – Storage Phasing Analysis, as presented in Table 1,
additional storage does not appear to be required until sometime between 2020 and 2025 and so, the
City could delay construction of additional water storage facilities for several years.
When Well 16 is put on line, the City will be able determine if the water from Well 16 will need
blending and if so, whether a GSR structure is needed or if transmission main blending will suffice.
If the City chooses to construct a water treatment facility at the Well 14 site, a GSR tank may or may
not be needed for plant operations, but this depends on the type of facility constructed. It is
recommended that the City use the delay in storage needs to review its plan for municipal water
treatment.
Question #2: Timing of the GSR Project
The following conclusions and notations are offered:
As noted above, additional storage does not appear to be required until sometime between 2020 and
2025.
From a blending perspective, the City may need to construct a GSR earlier than the 2020-2025 time
frame if it is determined that the water from Well 16 will need blending and it is demonstrated that
transmission main blending will not work
Question #3: Type of Storage Selected
The following conclusions and notations are offered:
Based upon our analysis, construction of a 1.5 MG composite style elevated water storage tank
actually appears to have lower capital and 50-year present worth maintenance costs when compared
to the proposed GSR and Booster Station project.
It is recommended that the City use the delay in storage needs to review its comprehensive water
system plan with respect to the construction of water storage facilities.
An elevated water storage tank constructed near the UMore property along County Road 42 will
provide suitable operation under current demand and storage conditions as well as those projected
the 2040 and Ultimate systems.
Question #4: Location of the Proposed GSR Project
The following conclusions and notations are offered:
The City’s Comprehensive Water System Plan identifies a GSR facility at the Well 14 site, but at this
point, this location is not critical for future development of the water system infrastructure.
From a water system operation perspective, the proposed GSR and booster station located at the
Well 14 site will provide suitable operation under current demand and storage conditions as well as
those projected the 2040 and Ultimate systems.
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 4
Question #5: Opportunities for Cost Savings Associated with the Proposed GSR Project
The following conclusions and notations are offered to identify potential opportunities for cost saving
associated with the GSR project in the event that the City still wishes to forward with the project either
now, or at some point in the future. While some of the cost saving opportunities suggested below could
be combined for added savings, it is not our intent to build a cumulative savings list. It is also important to
recognize that with these cost savings, concessions in the current project scope, aesthetics and capacity
may be necessary.
Implement the GSR project with bid alternates B and C, which will save $547,000 off of the base bid.
It is recommended that the City consider raising the entire hydraulic grade of the GSR structure and
booster station pumping chamber to reduce earthwork costs. It is estimated that a savings of
$450,000, or more can be realized if the City is willing to have the GSR tank sidewalls more exposed.
If the City wishes to have the entire GSR tank buried, it is recommended that the City pursue
obtaining a temporary construction easement from the property owner to the west to allow the
excavation back slope to flattened and unshored. The existing water main running along the western
edge of the site may need to be temporarily relocated and so we estimate that this option may only
generate $100K in savings to the base bid construction cost.
Placement of a round tank on the small, rectangular site, does not appear to make the most efficient
use of the site. The City should consider design of a cast-in-place rectangular GSR tank with integral
booster station located on top. It is estimated that this would result in more than $200,000 in savings
on facility construction and earthwork costs.
The proposed Booster Station has an approximate 250,000 gallon pumping chamber. If 1.5MG is
what the City is looking for at this site, the City should consider reducing the size of the proposed
GSR to be 1.25MG. It is estimated that a savings of $50,000 in tank and earthwork costs could be
realized.
A rectangular tank with the booster station on top would take up significantly less room on the site.
This would allow for design flexibility for the proposed water treatment plant. In addition, a cast-in-
place concrete tank can be expanded or modified whereas a pre-stressed wire wound tank cannot be
modified.
Consider replacing the proposed vertical turbine pump booster station with a horizontal centrifugal
pump booster station and then constructing the proposed GSR tank to be fully above the centerline
elevation of the centrifugal pumps. It is estimated that this configuration could save approximately
$1,000,000 off the current project costs.
WATER SYSTEM PLANNING REVIEW
Planning for additional water storage in Rosemount has been underway for quite some time. Review of
the as-bid GSR project must be placed in the context of prior engineering studies and then updated to
take into account the latest development planning. The 2007 Comprehensive Water System Plan1
anticipated needing additional storage at the NW WTP site within 6 to 10 years (2013 to 2017). Planning
since 2007 has been updated several times2 to account for changing development trends, culminating in
the April 29, 2015 West Pressure Zone Water Supply and Storage Evaluation Technical Memo. The
conclusion of this April 2015 Memo was that additional storage was required immediately (in the form of a
1 Comprehensive Water System Plan, August 1, 2007, WSB & Assoc.
2 Well 16 and Water System Issues Technical Memorandum, August 11, 2014, WSB & Assoc.
UMore Development Utilities Evaluation, Nov. 10, 2014, WSB & Assoc.
Water Storage/Supply Capacity Evaluation Update, Jan. 8, 2015, WSB & Assoc.
Water Supply and Storage Capacity Evaluation – West Pressure Zone, April 29, 2015, WSB & Assoc.
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 5
GSR project at the proposed NW WTP site), and one additional well (in addition to Well 16) may need to
be considered in the near future.
WATER DEMANDS AND SUPPLY – STORAGE PHASING ANALYSIS
The following analysis provides a comparison of the April 2015 conclusions to current development
expectations – primarily delays with the UMore development, delays with infill of existing platted property,
and delay in new development proposals in the West Side of Rosemount. It is important to note that this
memo only directly addresses development in the West Pressure Zone of Rosemount – however,
development in eastern Rosemount significantly impacts the need, timing, and optimal location of
additional supply and storage. Since water can flow from the West Pressure Zone to the East Pressure
Zone by gravity, the projected growth in the East Side could be served from supply and storage facilities
in the West Side – as long as adequate piping is installed to convey the supply to the East side service
area.
Table 1 provides a summary of supply/storage recommendations. The data in this table comes primarily
from the April 2015 WSB Tech Memo, and has been updated based on our understanding of current and
expected future development trends; as well as extending all well operations to 24 hour/day and having
only one well out of service for supply and storage calculations (as discussed at various meetings with
WSB and City staff). Another important element in our update was to use the per capita max day water
demand value of 365 gpcd identified in the April 2015 memorandum for our calculations of required
supply through the Year 2030. This is slightly more conservative than the average value of 301 gpcd but
for supply being a little more conservative may be warranted. Our calculations continue after 2030 using
the lower 301 gpcd value following the assumption that City demands for higher water use will diminish as
more and more lawns have become established.
For discussions of storage capacity, per capita max day water demand values ranging from 301 gpcd to
365 gpcd are reasonable and can be inclusive of climate conditions and how successful water
conservation measures are. In Table 1, we offer the same conservative approach to water usage as
discussed previously for supply.
The estimated years in Table 1 are provided only for general capital improvement planning purposes.
Actual development may occur faster or slower than projected in this table. Similarly, population
projections are not a true indicator of when additional facilities are required. The population projections
are provided to give a sense of how much additional development could occur before required expansion
– assuming similar overall water use to existing trends. Adding large water using industrial customers
would change the ratio of water use to population.
Facility expansion needs are based on actual and near-term projected water use, using the water
demand “triggers” provided in Table 1. As development proposals come in to the City, a review of existing
and proposed Maximum Day water use allows the City to determine the need for added facilities. Design
of facilities should start 2 years prior to the need for the facilities. Site acquisition should occur prior to
design, preferably as part of the development platting process.
In summary, Table 1 establishes the water supply and storage phasing plan that is conservatively build
around a per capita max day water demand value of 365 gpcd through the Year 2030 and then 301 gpcd
thereafter. In terms of supply, the City has adequate supply capacity beyond 2020 (with Well 16 in
service) to support at least 6,400 additional people and this includes infill of existing platted lots, plus full
development of UMore Phases 1 and 5. In terms of storage, Table 1 shows that with Well 16 and future
Well 17 in service, the City can have adequate storage capacity beyond 2020 to support approximately
4,400 people.
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 6
Conclusion: As can be seen in Table 1, additional storage is not required until sometime between 2020
and 2025 and so, the contemplated construction of the GSR project could be delayed for
some time.
COMPARISON OF WATER STORAGE TYPES
Peak hourly demands throughout the system are met from water supply sources (wells) and water drawn
from storage facilities. Although the rate of consumption during peak hour is very high, the duration is
short. A moderate amount of water supplied from strategically located storage facilities throughout the
system provides satisfactory service (pressure and flow) to all users, while minimizing the total peak hour
pumping required, minimizes distribution pipe sizing, and permits more uniform operation of supply
facilities. System storage also increases the reliability of service by providing additional supply in the
event of a mechanical breakdown, power outage, or fire. Storage facilities can be provided in one of two
ways: a gravity feed (elevated tank) systems or pumped systems.
In an elevated gravity feed system (such as an elevated water tower), a water reservoir is supported
above the ground with a support column. The height of the water in the tower provides pressure to the
system. Water pumped from the supply sources flows into the tank during periods of low demand, and
water flows out of the tank to supplement water pumped from supply during periods of high demand.
A pumped system consists of a storage reservoir built at or just under ground level. To provide pressure
and flow to the system, the water must be pumped out of the tank. Since this system relies on mechanical
equipment and electricity to provide any storage value, back-up pumps, equipment, and power source are
provided to approximate the reliability of elevated gravity feed systems.
Comparative Cost Estimates
The April 28, 2015 Rosemount Water Storage Capacity Evaluation memorandum provided a comparison
of capital and maintenance costs for the GSR and booster station and two (2) different styles of elevated
tanks. The comparison identified the GSR and Booster Station option to have the lowest capital and
maintenance costs of the three (3) options considered. As part of our analysis, we performed a similar
evaluation. For the capital costs, we used the base bid pricing recently received for the GSR and booster
station and costs of elevated tanks from our recent past projects. For the 50 year present worth
evaluation, we included an analysis of the GSR project using our standard procedures and included the
cost of maintaining elevated water tanks provided by our design/build tank maintenance subsidiary.
As noted in the following table, our analysis concluded that either elevated tank option would have lower
capital and 50 year present worth maintenance costs:
In an April 2015 memorandum, construction cost of the GSR and two (2) different styles of elevated tanks
were estimated at $4.14M, $4.47M and $4.29M, respectively.
Capital & Maintenance Costs
Ground Storage Reservoir/Booster Station and Elevated Water Storage Tank Options
SEH Peer Review
GSR & Booster Station Project
Rosemount, MN
Option Capital Cost* 50 Year Maintenance
Cost
Total Capital &
Maintenance Costs
Option A - 1.5 MG
Ground Storage
Reservoir & Booster
Station
$5,548,000 $1,479,548 $7,027,548
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 7
Capital & Maintenance Costs
Ground Storage Reservoir/Booster Station and Elevated Water Storage Tank Options
SEH Peer Review
GSR & Booster Station Project
Rosemount, MN
Option B - 1.5 MG
Fluted Column Style
Water Tower
$4,314,000 $2,813,800 $7,127,800
Option C - 1.5 MG
Composite Style
Water Tower
$4,291,000 $1,732,100 $6,023,100
Lake Elmo 1.0 MG
Composite bid
2/25/2016
$2,587,300 $1,333,600 $3,920,900
Lakeville 2.0 MG
Composite bid
2/11/2015
$3,683,000 $2,119,600 $5,802,600
*Capital costs listed are construction costs only and do not include engineering, or admin fees.
$150k in land costs are included in the water tower options B & C.
Conclusion: Construction of a 1.5 MG composite style elevated water storage tank appears to actually
have the lowest capital and 50-year maintenance costs.
WATER MODEL REVIEW AND UPDATE
For purposes of this analysis, the City’s existing water models, provided by WSB (as two separate models
for the existing and ultimate water systems) were reviewed with current GIS water main information and
system function. Since the focus for water storage needs pertain to the west pressure zone, this zone
was analyzed independently in the water system model, however it is important to note that development
of the East Service Area could add stress to the West Side system, or require additional investment in
supply and storage facilities in eastern Rosemount.
For our analyses, water system demands were updated in the model to reflect current and projected
water system Demand levels. The April 29, 2015 Rosemount Water Supply and Storage Capacity
Evaluation – West Pressure Zone was reviewed in relation to projected water system demands and
anticipated water supply facilities. Multiple water system scenarios were developed using the model to
reflect potential water system storage options at various projected growth levels. The three primary water
system growth scenarios that were examined in relation to the proposed GSR (ground storage reservoir)
include:
Current water system - Updated to reflect proposed facility operation in 2017
Projected development of the water system equated to a service population of 45,843 people in the
west pressure zone. (As defined in the April 29, 2015 memo)
Ultimate Water System (As defined in the 2007 comprehensive water plan)
For each of these scenarios, physical facilities were reviewed and modified in the model to reflect the
construction of a proposed 1.5 MG GSR and a 6,000 gpm (expandable to 9,000 gpm) booster station
near the existing Bacardi elevated water storage tank. The ground storage reservoir was modeled to
accept water flow from multiple supply wells including existing well Nos. 14, 15, 16, and proposed future
water supply wells operating with a total firm capacity of up to 7,500 gallons per minute from Wellfield
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 8
No. 2. The actual firm well capacities were adjusted to match with the needs of the system growth
scenario being analyzed. The actual firm booster station pump capacity was adjusted between two (2),
three (3) and four (4) 3,000 gpm pumps to match with the needs of the system growth scenario being
analyzed.
Each of these scenarios, identified above, were developed to include an extended period simulation
(EPS), which imitates real water system operation over a multiple hour period that includes maximum day
water demands. For the purpose of analyzing the system operation on/off controls we excluded from the
operation with the wells set at a constant rate to match system demand. The removes a highly variable
element from the analysis. This sort of modeling allows for the water supply and storage facilities
operation to be analyzed relative to one another and helps to develop an understanding of the
effectiveness of the facilities and how each water facility might operate in the future. The use of the EPS
allows for the water system to be analyzed exclusive of complex controls in relation to:
Change in water storage tank levels over time (tank balance)
Water storage fill and empty rates
Reserve water storage on hand
Equalization water storage
Extended water age
Water system supply and storage influence
Dynamic system pressure.
2017 WATER SYSTEM WITH GSR ANALYSIS
For purposes of analyzing the proposed GSR operation in conjunction with the exiting water facilities, a
scenario within the water model was developed to reflect current water system conditions and demand
levels. The proposed GSR was set to match the proposed facility plans and was modeled to accept flow
from well Nos. 14, 15 and 16. Water is moved from the GSR to the distribution system by a pair of high
service pumps, rated for 3,000 gpm each. The GSR booster pumping system was modeled with two
different operational schemes.
Operation A was modeled with the assumption that the flow from the wells into the GSR matches the flow
out of the GSR, while operating the booster station at a constant rate for the duration of the extended
period analysis. This effectively treats the GSR as a reserve storage facility with the water flowing into the
tank equaling the water flowing out on a minute by minute basis.
Operation B was modeled with the expressed goal of utilizing a large portion of the GSR reserve storage
while pumping water into the system from the high service pumps at a greater rate than the wells during
peak system demands. This operational scheme was set to have the GSR mimic the operation of an
elevated storage tank, with the GSR pumping system providing flow to the system in a greater quantity
than the wells are capable of supplying. In turn, this operation would draw tank levels down during peak
demand conditions.
The system described above was operated for an extended period within the water model assume current
maximum day demand conditions. Tank levels and booster station flow data was then tracked and
documented.
Model Figure 1.1 shows that when the model was operated as described above, when demand levels
increase throughout the day and exceed supply capacity (Between hours 3 and 7) , existing elevated
water tank levels begin to drop in order to satisfy system demands. Water used during this time period is
known as “equalization storage”. Later in the day, as demand levels drop below the rate of supply, the
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 9
tanks begin to fill once again. Under this scenario, the elevated tanks, including the nearby Bacardi water
tower work to satisfy the systems “equalization storage” needs.
Operation B (See Model figure 1.1) documents an operational option by which “equalization storage” is
partially provided from the GSR. As demand levels increase throughout the day, and exceed supply
capacity (Between hours 3 and 7) existing elevated water tank levels (excluding the Bacardi tank), as well
as the GSR begin to drop in order to satisfy system demands. During this time, the outgoing GSR
pumping rate exceeds the incoming well supply rate which helps to satisfy system demand levels,
reducing the water level in the GSR. However, increasing use of the GSR reduces equalization provided
by the Bacardi, essentially trading use of one tank for the other,
Conclusion: This analysis concluded that there is more than enough storage currently available to allow
for system equalization. If the proposed GSR were placed online with current demand
levels, equalization storage from this facility would not be necessary, but would provide
reserve storage. Until peak hour demands on the water system exceed the well pumping
capacity and existing elevated storage tank equalization capacities, water supply from the
wells will simply be pumped to the proposed GSR, where it is re-pumped into the distribution
system. If the system was operated to utilize more of the GSR volume for equalization
(Operation B), the Bacardi tank would remain full and receive little use. In essence, since the
GSR is located near the Bacardi tank, the emphasis of use of on tank will discount the other.
DESIGN YEAR 2040 WEST PRESSURE ZONE WATER SYSTEM WITH GSR ANALYSIS - SERVICE
POPULATION = 45,843
For purposes of this analysis, a projected intermediate water system scenario was developed to reflect
projected maximum day water system demands and anticipated water system build out when the west
pressure zone Service population reaches 45,843 people. While it is not possible to simulate the exact
future system configuration that might exist at this point in time, such an exercise allows a better
understanding of how the future water system might operate when the GSR will be at full operational
potential.
In a similar exercise to that which was completed for the existing system, the water levels in the west
zone water storage tanks were examined during an extended period maximum daily demand scenario
utilizing two different operating schemes:
Model figure 1.2 (Operation A), shows all system water storage tanks drop to the lowest levels around
hour 7, which follows shortly after the peak demand period of the day. Even at their lowest levels, the
combination of the remaining water in the storage tanks is greater than the reserve firefighting storage
required.
Operation B shown in model figure 1.2, shows all system water storage tanks maintaining higher water
levels than the previous scenario (Operation A) due to higher flows being pushed into the system from the
GSR and filling the elevated storage tanks. Once again the Bacardi tank has very little water drawn out of
storage with the GSR providing the majority of the “system equalization” storage for the operation.
Conclusion: Through operation of the model utilizing this scenario, the results indicate that varying
volumes of water could be consumed from the GSR during a maximum daily operation to
provide water system equalization depending on operational settings. Higher amounts of
water could be pulled from the GSR by modifying system controls to increase the pumping
rate. However, the systematic increase in draw of water from the GSR will in turn limit the
flow from the Bacardi tank.
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 10
ULTIMATE WATER SYSTEM WITH GSR ANALYSIS
For analysis of the ultimate water system, the ultimate water system model was updated to reflect the
proposed GSR and Booster station facilities. An EPS was then modeled with the other current and future
water system facilities including the proposed Southwest water treatment plant and Southwest (SW)
elevated storage tank. The location of the SW Elevated tank could be located either in the location shown
in the 2007 Plan, or moved to the east to support fire flows for the UMore property, with similar hydraulic
results.
Figure 1.3 (Operation A) shows that under this scenario with maximum day demands, all system water
storage tanks were noted to drop to their lowest levels around hour 7, which follows shortly after the peak
demand within that day. The future Southwest water tank dropped to the lowest level do to its close
proximity to anticipated demands and long distance from major supply sources and Bacardi maintained
the highest tank level since it is near a major supply source. Operating in this manor would maintain
reserve storage within the GSR and equalization would be served by the elevated storage tanks,
Operation B on the same figure documents operation of the system while systematically increasing use of
the GSR. Similar to the previous exercise, this scenario was modeled with the GSR booster station
having the capability to operate beyond the capacity of the well pumps during peak system demands.
Results of this model operation should elevated tank levels dropping to a similar level as shown in for
operation A with the exception of Bacardi. The increased flow from the GRS pumping maintains water
levels in the Bacardi tank nearly full.
Conclusion: Modeling this scenario, results indicate that varying amounts of water could be supplied from
the GSR during a maximum daily operation to provide water system equalization depending
on system control settings. The hydraulic lag between the elevated tanks most near to the
GSR (Bacardi) and those tanks located more remotely is very pronounced, especially for the
proposed SW tank. Altitude valves are required at all three existing elevated tanks to provide
satisfactory service to the SW water tower.
HYDRAULIC IMPACT OF DEVELOPMENT OF THE EASTERN SERVICE AREA
Analysis of the eastern service area and its impact on the hydraulic performance of the proposed system
is beyond the scope of this peer review. However, a few general observations can be made:
The analysis and results presented above are valid only if an assumption is made that development
of the East Service area will include addition of its own supply and storage. Obviously, this may not
be the most cost effective interim solution since the City may have to construct supply and storage
facilities in both the East side and the West side.
Development of the East side can occur up to the capacity of the existing rural wells and existing East
side storage facility without any impact on the west side system.
As eastern water demands exceed the capacity of the existing east side facilities, additional supply
and storage facilities are required. If the City desires to utilize the excess capacity of the west zone
facilities, the maximum day, peak hour, and fire flows in excess of the capacity of the existing east
side water tower must be conveyed from western supply and storage facilities, through existing trunk
mains, and through a single 2 mile long 16 inch trunk main to get to the point of use. At some point,
the capacity of this single main will be exceeded and an additional 2 mile long trunk pipe is required
(parallel to trunk pipes required to serve the UMore property south of CSAH 42, which is all on the
West Service Area).
ELEVATED WATER STORAGE TANK (EWST) ALTERNATIVE MODEL ANALYSIS
Previous water system memos explored the option of elevated water storage in lieu of the proposed GSR.
For purposes of our analysis, the proposed plan to add water supply sources near the Bacardi tank is
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 11
continued and a new 1.5 MG water tower is constructed in the vicinity of the U-more development,
connected to the existing 16-inch trunk main along County Road 42.
Operation of Existing System with a New EWST
Upon initial operation of this EWST, using similar demand levels and water main infrastructure to that
which exists today, Model Figure 2.1 shows water levels in the new water tower (Umore) would be very
similar the Bacardi tank hydraulically, following a similar fill/empty trend at a slightly increased HGL/tank
level. This is because current demand levels and a strong network of trunk main would allow for the
tanks to empty and fill evenly, resulting in consistent tank trends, with Bacardi operating at a higher level
due to its proximity to nearby water supply wells. However, similar to the previous GSR scenarios, the
Bacardi tank may require an altitude valve to prevent tank overflow due to proximity to the supply source.
But in this instance, the Bacardi tank would be provide a larger amount of equalization storage during
peak demand periods. In short, the addition of an elevated storage tank at this location, initially would
result in the new storage tank sharing work with the Bacardi tank to serve the eastern portion of the West
pressure zone.
Conclusion: An elevated water storage tank located near the UMore property will function properly and
provide adequate storage under this existing system Max Day scenario. The modeling
reflects having an altitude valve on the Bacardi tank due to the large amount of water being
supplied to the system from the nearby wells.
Design year 2040 West Pressure Zone Water System with EWST Analysis - Service Population = 45,843
As shown in Model Figure 2.2, performing a similar analysis using future demands results in the water
levels in the proposed EWST lagging behind the Bacardi tank. This is due to high levels of water demand
expected in the Umore development area. However, as shown in Model Figure 2.2, if a tank were
constructed in this location, it is expected that tank would provide a large amount of flow to meet peak
hour demands. The low tank levels could be remedied by installing an altitude valve at the Bacardi tank,
which would allow for water to be directed toward the Umore development and allow for the Umore tank
to fill to higher levels, increasing service pressure in the Umore area.
Conclusion: An elevated water storage tank located near the UMore property will function properly and
provide adequate storage under this 2040 Max Day scenario.
Ultimate Water System with EWST Analysis
Continuing the analysis noted in the previous paragraph, under ultimate water system demands, Model
Figure 2.3 shows that the Bacardi tank and existing west pressure zone tanks would operate at higher
levels than the proposed Umore tank due to high levels of demands in the area of the Umore
development and proximity to supply sources. Under this scenario, the future Southwest tank operates in
a nearly identical fashion to that of the Umore tank.
Conclusion: An elevated water storage tank located near the UMore property would function properly
and provide adequate storage under this Ultimate Max Day scenario. However, due to the
proximity of the Bacardi tank to the major well supply, the Bacardi tank would tend to
operate at a higher level.
In summary, the Bacardi tank would be influenced the most by future supply and storage changes.
Regardless of the choice between a GSR or elevated tank, the volume utilized from each of the existing
tanks will be influenced to varying degrees. The biggest influence on operation of the Bacardi tank results
from increased supply pumping at Wellfield No.2 (Well Nos. 14, 15 & 16). This is further magnified by
increasing supply pumping rates through use of a GSR and pumping station. If the GSR facility is
constructed, it will function and serve the City appropriately however the need for the Bacardi tank will be
reduced.
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 12
GSR BID DOCUMENT REVIEW & SITE PLANNING
The purpose of this section is to identify potential opportunities for cost saving associated with the GSR
project in the event that the City still wishes to move forward with the project either now, or at some point
in the future. While some of the cost saving opportunities suggested below could be combined for added
savings, it is not our intent to build a cumulative savings list. It is also important to recognize that with
these cost savings, concessions in the current project scope, aesthetics and capacity may be necessary.
Project Bid Alternatives
A review of the bids received on the GSR project and the alternates reveals two significant cost saving
elements. The first one is schedule. The base bid project has a very tight time frame for completion.
Recognizing that there is no real need for the project to be completed any time soon, the tight schedule
requirements should be lifted. This will provide a savings of ($154,400) off of the low bid of $5,548,000
on the base bid project requirements and the low bid of $5,393,600 under the Alternate C award option.
The second cost saving element is earthwork. Under the base bid design, the entire GSR structure is
proposed to be buried. To do so involves a significant amount of earthwork and shoring. Bid Alternates
A and B include changes to the base bid to allow a portion of the GSR to be exposed. From a review of
the bids, it is evident that as more tank wall is exposed and less total structural tank sidewall is required,
the cost of the project can be reduced. Under Bid Alternate A, the GSR is exposed with a domed roof
structure, an 8-foot exposed sidewall and a significant amount of freeboard, or unusable volume in the
tank. Under Bid Alternate B, the GSR is exposed with a domed roof structure and 2-foot exposed
sidewall. Price deducts from the low base bid for these alternates are ($210,000) and ($337,000),
respectively. Under each of these alternatives, as well as with the base bid, the pumping chamber
associated with the booster station is still constructed as a very deep structure.
Exposed GSR Sidewall and Project Costs
From a review of the bids and the above discussion, it is apparent that the cost of the project decreases
as more of the GSR structure is exposed. Using this rationale, it is recommended that the City consider
raising the entire hydraulic grade of the GSR structure and booster station pumping chamber to reduce
earthwork costs. It is estimated that a savings of $450,000, or more can be realized if the City is willing to
have the GSR tank sidewalls more exposed. Sites with exposed round GSR tanks can be viewed in
many cities including South Saint Paul, Inver Grove Heights and Shakopee to name a few.
If the City wishes to have the entire GSR tank buried, it is recommended that the City pursue obtaining a
temporary construction easement from the property owner to the west to allow the excavation back slope
to flattened and unshored. The existing water main running along the western edge of the site may need
to be temporarily relocated and so we estimate that this option may only generate $100K in savings to the
base bid construction cost.
Rectangular GSR versus Round GSR
The site for the proposed GSR project is rectilinear in shape and smaller in size with boundary conditions
on all four sides. The proposed GSR and booster station project includes a round pre-stressed wire
wound concrete GSR tank. Placement of a round tank on the small, rectangular site, does not appear to
make the most efficient use of the site. It is likely that the round GSR was selected over a rectangular
poured-in-place GSR because the construction cost are typically less. This is true if the booster station
and rectangular GSR are designed as separate structures. However, if the booster station were to be
located on top of a rectangular cast-in-place concrete GSR, the overall cost for the project would be less
(see attached Option 1 - Section). The bid price for the round GSR was $1,271,000 plus an additional
$687,000 for poured-in-place concrete for the booster station structure (total cost $1,958,000). The total
estimated concrete cost for a rectangular tank with integral pumping chamber and booster station on top
is $1,780,000. This would result in approximately $200,000 in savings assuming all other costs are
Rosemount GSR & Booster Station Peer Review
May 6, 2016
Page 13
equal. In addition, combining the GSR and the booster station into one structure would include
significantly less earthwork which would result in even lower construction cost.
A rectangular tank with the booster station on top would take up significantly less room on the site (see
attached Option 1 – Site Plan). This would allow for design flexibility for the proposed water treatment
plant. In addition, a cast-in-place concrete tank can be expanded or modified whereas a pre-stressed
wire wound tank cannot be modified. It should be noted that portions of the rectangular tank would be
exposed to view. This quite common and rectangular tanks with exposed sidewalls can be viewed in
many cities including the nearby communities of Apple Valley and Inver Grove Heights.
GSR Tank Size Reduction
The proposed Booster Station has an approximate 250,000 gallon pumping chamber. If 1.5MG is what
the City is looking for at this site, the City should consider reducing the size of the proposed GSR to be
1.25MG. It is estimated that a savings of $50,000 in tank and earthwork costs could be realized.
Horizontal Centrifugal Pumps and Exposed GSR Tank
Under this scenario, the design would be changed to eliminate the vertical turbine style booster station
and replace it with a horizontal centrifugal style booster station. The alternate booster station would be
located on the southern end of the site and the GSR tank positioned to the north of the booster station. In
order to maintain gravity feed from the GSR to the pump station while maximizing the useable volume of
water in the GSR, the base slab of the GSR tank would need to be set approximately 4 feet above the
centerline of the pumps.
By laying out the facilities as described above, the pumping chamber is eliminated from the booster
station and the earthwork cost are significantly reduced from that of the current base bid design. By
implementing this design configuration, it is estimated that the City could save $1,000,000 in construction
costs.
End.
s:\pt\r\rosem\136006\4-prelim-dsgn-rpts\gsr_review_memo_5may2016 - ah-mbj edit.docx
Attachments
(MGD)(gpm)Required (3)Existing
Existing
minus
Required
Ave Day
Guideline (4)
EQ Plus Fire
(5)Existing Improvements (Placed into service)
2016 23,544 0 23,544 2.57 8.59 5,968 9,548 5,968 7,600 (7)1,632 2.57 2.49 3.0
2017 23,857 0 23,857 2.60 8.71 6,047 9,675 6,047 7,600 (7)1,553 2.60 2.53 3.0
2018 24,210 0 24,210 2.64 8.84 6,137 9,818 6,137 7,600 (7)1,463 2.64 2.58 3.0
2019 24,602 349 (11a)24,951 2.72 9.11 6,324 10,119 6,324 7,600 (7)1,276 2.72 2.68 3.0
2020 25,320 706 (11a)26,026 2.84 9.50 6,597 10,555 6,597 7,600 (7)1,003 2.84 2.82 3.0
2025 28,502 (11)2,468 (11b)30,970 3.38 11.30 7,850 12,560 7,850 8,800 (7)950 3.38 3.29 4.5 Add one west side well. Add 1.5 MG Storage
2030 31,701 (11)4,220 (11c)35,921 3.92 13.11 9,105 14,568 9,105 10,000(12)895 3.92 3.74 4.5
2035 34,900 (11)5,982 (11d)40,882 4.46 13.11 9,105 14,568 9,105 10,000 (12)895 4.46 3.76 4.5
2040 38,100 (10)7,743 (10)45,843 5.00 (10)13.80 9,856 15,770 9,856 10,000 (12)144 5.00 4.00 4.5
Ultimate 70,000 (14)(8)70,000 (14)7.63 (14)21.07 (14)14,630 (14)23,408 14,630 14,800 (15)170 7.63 5.87 6.0 (16)
Prior to ultimate build-out: Add 4 west side
wells. Consider one additional well for back-
up. Add 1.5 MG storage
Notes
1 Source: WSB Tech Memo April 29, 2015 unless otherwise noted
2 1.6x MDD per April 2015 WSB Tech Memo
3 Supply firm capacity required = 100% of Maximum Day Demand
4 GLUMRB Recommended Standards for Waterworks
5 Equalization storage per WSB April 29, 2015 Memo Spreadsheet (25% EQ plus fire demand (630,000 gal) minus excess supply). Well supply for full 24 hours on MD. Tanks allowed to drop >50% if fire at peak hour of Max Day.
6a ADD calucalted at 109 gpcd per WSB April 29, 2015 Memo.
6b
7 Well 7, 8, 9, 12, 14, 15 with Well 16 (at assumed 2,000 gpm) on standby (source: WSB Tech Memo April 29, 2015, April 2016 WSB Well 16 Pump Test data)
8 Remainder of Umore build-out is included in the 70,000 people projected per WSB
9 Not used
10 38,100 per Metropolitan Council 2040 Forcast and WSB Tech Memo April 29, 2015; plus UMore Phases 1 - 5 fully developed at rates provided in Nov 2014 WSB Umore Report Appendix 1
11 Population interpolated straight line between forcast
11a Assume Umore construction begins in 2018
11b Includes most of Umore Area 1 and most of Area 5
11c Includes remainder of Umore Area 1 & 5, and a portion of Area 2
11d Includes all of Umore Areas 1 & 5, and most of Area 2
12 Assume future wells average 1,200 gpm each
13 Table in April 2015 WSB Memo - Corrected to 13.8 MGD
14 Source: West Side Only from Table 9, August 2007 WSB Comprehensive Water System Plan (adjusted for MDD/ADD ratio of 2.76)
15 Review MDD at Build-out. Total 6 additional wells required. Consider one additional back-up well when over 10 total wells. May need one additional well if MDD is significantly greater than 14,400 gpm
16 Minimum 6.0 MG storage required for equalization. Consider clearwell storage at water plants for operational flexibility and to get closer to GLUMRB average day storage recommendation
MDD Range estimated by using 301 gpcd (per April 29, 2015 WSB Memo), and more conservatively assumed at 365 gpcd (highest recorded MDD per capita per WSB Jan 2015 Memo) through 2030. Use MD at 301 gpcd (assuming success of
conservation measures) beyond 2030.
Table 1
Rosemount West Pressure Zone Supply - Storage Phasing
Storage (MG)Peak Hour
Demand (2)
(gpm)
Average Day
Demand (6a)
(MGD)
Maximum Day Demand (6b)
Year
Ending
Population
Served (1)
Supply (gpm)Population
Served from
UMore
Total
Population
Served
945
950
955
960
965
970
975
980
985
1,065
1,070
1,075
1,080
1,085
1,090
1,095
1,100
1,105
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Ground Storage Reservoir Level (ft.)Elevated Storage Tank Water Level / Hydraulic Grade (ft.)Hours
Figure 1 -2017 Water System W/GSR -Max Day EPS Tank Levels
Bacardi Tower
Connemara Tower
Chippendale Tower
Ground Storage Reservoir
Water used for operations (pumps on/off)
Water supply rate into GSR = Water supply rate out to distribution
945
950
955
960
965
970
975
980
985
1,065
1,070
1,075
1,080
1,085
1,090
1,095
1,100
1,105
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Ground Storage Reservoir Level (ft.)Elevated Storage Tank Water Level / Hydraulic Grade (ft.)Hours
Figure 2 -2040 Water System W/GSR -Max Day EPS Tank Levels
Bacardi Tower
Connemara Tower
Chippendale Tower
Ground Storage Reservoir
Water Used for Equalization: Water supply rate to distribution is greater than GSR well supply rate
Water used for operations (pumps on/off)
420,00 Gallons +/-(*GST equalization is heavily influenced by HSP control settings)
945
950
955
960
965
970
975
980
985
1,065
1,070
1,075
1,080
1,085
1,090
1,095
1,100
1,105
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Ground Storage Reservoir Level (ft.)Elevated Storage Tank Water Level / Hydraulic Grade (ft.)Hours
Figure 3 -Ultimate Water System W/GSR -Max Day EPS Tank Levels
Bacardi Tower
Connemara Tower
Chippendale Tower
Future SW Tower
Ground Storage Reservoir
Water Used for Equalization: Water supply rate to distribution is greater than GSR well supply rate
Water Supply Rate into GSR = Water supply rate out to distribution Water used for operations (pumps on/off)
240,00Gallons +/-(*GST equalization is heavily influenced by HSP control settings)
1,065
1,070
1,075
1,080
1,085
1,090
1,095
1,100
1,105
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48Elevated Storage Tank Water Level / Hydraulic Grade (ft.)Hours
Figure 4 -2017 Water System W/EWST -Max Day EPS Tank Levels
Bacardi Tower
Connemara Tower
Chippendale Tower
Proposed Umore Tower
1,065
1,070
1,075
1,080
1,085
1,090
1,095
1,100
1,105
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48Elevated Storage Tank Water Level / Hydraulic Grade (ft.)Hours
Figure 5A -2040 Water System W/EWST -Max Day EPS Tank Levels
Bacardi Tower
Connemara Tower
Chippendale Tower
Proposed Umore Tower
1,065
1,070
1,075
1,080
1,085
1,090
1,095
1,100
1,105
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48Elevated Storage Tank Water Level / Hydraulic Grade (ft.)Hours
Figure 5B -2040 Water System W/EWST -Max Day EPS Tank Levels* Umore Controls
Bacardi Tower
Connemara Tower
Chippendale Tower
Proposed Umore Tower
1,065
1,070
1,075
1,080
1,085
1,090
1,095
1,100
1,105
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48Elevated Storage Tank Water Level / Hydraulic Grade (ft.)Hours
Figure 6A -Ultimate Water System W/EWST -Max Day EPS Tank Levels
Bacardi Tower
Connemara Tower
Chippendale Tower
Proposed Umore Tower
1,065
1,070
1,075
1,080
1,085
1,090
1,095
1,100
1,105
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48Elevated Storage Tank Water Level / Hydraulic Grade (ft.)Hours
Figure 6B -Ultimate Water System W/EWST -Max Day EPS Tank Levels * Umore Controls
Bacardi Tower
Connemara Tower
Chippendale Tower
Proposed Umore Tower
/ƚƒƦƚƭźƷĻ
Exterior15,460SqFt
TankSize1,000,000GallonSurfaceAreaInteriorWet19,530SqFt
InteriorDryN/ASqFt
YearWorkDescriptionCost
2WarrantyInspectionandCorrections(IncludedinCostofTankConstruction)$
7PeriodicInspection&Maintenance$2,500.00
12PeriodicInspection&Maintenance(IncludePressureWash)$6,500.00
17Exterior/InteriorWetOvercoatReconditioning$353,600.00
19WarrantyInspectionandCorrections(IncludedinCostofTankReconditioning)$
24$3,000.00
PeriodicInspection&Maintenance
27Exterior/InteriorWet/InteriorDryCompleteRehabilitation$605,400.00
29$
WarrantyInspectionandCorrections(IncludedinCostofCompleteRehabilitation)
34PeriodicInspection&Maintenance$2,500.00
39PeriodicInspection&Maintenance(IncludePressureWash)$6,500.00
44Exterior/InteriorWetOvercoatReconditioning$353,600.00
46WarrantyInspectionandCorrections(IncludedinCostofTankReconditioning)$
51PeriodicInspection&Maintenance$3,000.00
Total$1,333,600.00
/ƚƒƦƚƭźƷĻ
25,090SqFt
Exterior
TankSize2,000,000GallonSurfaceAreaInteriorWet33,020SqFt
InteriorDryN/ASqFt
YearWorkDescriptionCost
2WarrantyInspectionandCorrections(IncludedinCostofTankConstruction)$
7PeriodicInspection&Maintenance$4,000.00
12PeriodicInspection&Maintenance(IncludePressureWash)$9,000.00
17Exterior/InteriorWetOvercoatReconditioning$560,900.00
19WarrantyInspectionandCorrections(IncludedinCostofTankReconditioning)$
24PeriodicInspection&Maintenance$5,000.00
27Exterior/InteriorWet/InteriorDryCompleteRehabilitation$966,800.00
29WarrantyInspectionandCorrections(IncludedinCostofCompleteRehabilitation)$
34PeriodicInspection&Maintenance$4,000.00
39PeriodicInspection&Maintenance(IncludePressureWash)$9,000.00
44Exterior/InteriorWetOvercoatReconditioning$560,900.00
46WarrantyInspectionandCorrections(IncludedinCostofTankReconditioning)$
51PeriodicInspection&Maintenance$4,000.00
Total$2,119,600.00
Notes:
Surfaceareasbasedonaheightof100feettothebaseofthetank.
Costsbasedon2016pricinganddonotadjustforincreasesordecreasesovertime.
Pricesbasedonengineeringfeesandcoatingrehabilitationonly.Repairsormodificationsarenotincluded.
Updated:5/4/2016
Annual Capital Cost First Second Third Salvage Total Materials
Capital Repair for Replacement Useful Replacement Replacement Replacement Salvage Value & Equipment
Division Item Cost Costs Items Life PW PW PW Value PW Replacement PW
1 General $661,000 11.88%$0 $661,000 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
2 Site Piping, Grading $1,131,500 20.34%$0 $1,131,500 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
3 Concrete $726,000 13.05%$0 $726,000 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
4 Masonry $165,000 2.97%$0 $165,000 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
5 Metals $35,000 0.63%$0 $35,000 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
6 Wood & Plastics $4,500 0.08%$0 $4,500 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
7 Thermal & Moisture $80,300 1.44%$0 $80,300 20 $80,300.00 $80,300.00 $0.00 $40,150.00 ($40,150.00)$120,450.00
8 Doors $12,000 0.22%$12 $13,700 15 $13,700.00 $13,700.00 $13,700.00 $9,133.33 ($9,133.33)$31,966.67
Windows $34,000 0.61%$0 $13,700 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
9 Finishes $37,000 0.66%$93 $37,000 15 $37,000.00 $37,000.00 $37,000.00 $24,666.67 ($24,666.67)$86,333.33
10 Specialties $1,271,000 22.84%$0 $1,271,000 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
11 Piping & Valves $308,500 5.54%$0 $50,000 25 $50,000.00 $0.00 $0.00 $0.00 $0.00 $50,000.00
VT Pumps $185,000 3.32%$0 $185,000 20 $185,000.00 $185,000.00 $0.00 $92,500.00 ($92,500.00)$277,500.00
Submersible Mixer $26,000 0.47%$0 $26,000 20 $26,000.00 $26,000.00 $0.00 $13,000.00 ($13,000.00)$39,000.00
12 Furnishings $0 0.00%$0 $0 25 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
13 Meters $10,200 0.18%$0 $10,200 20 $10,200.00 $10,200.00 $0.00 $5,100.00 ($5,100.00)$15,300.00
14 Conveying $0 0.00%$0 $0 25 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
15 Mechanical - Plumbing $33,500 0.60%$0 $0 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
Mechanical HVAC $147,500 2.65%$148 $147,500 25 $147,500.00 $0.00 $0.00 $0.00 $0.00 $147,500.00
16 Electrical $246,000 4.42%$0 $246,000 50 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
Electrical - Generator $150,000 2.70%$300 $150,000 25 $150,000.00 $0.00 $0.00 $0.00 $0.00 $150,000.00
Electrical - MCC/Controls $210,000 3.77%$42 $210,000 25 $210,000.00 $0.00 $0.00 $0.00 $0.00 $210,000.00
Electrical - VFDs $90,000 1.62%$90 $90,000 15 $90,000.00 $90,000.00 $90,000.00 $60,000.00 ($60,000.00)$210,000.00
TOTALS $5,564,000 100.00%$684 $5,253,400 $1,338,050
Capital Project Costs $5,564,000 $340,276 Interest =2.00%
Financing Years=20.00
Equipment Replacement $1,338,050 $42,581
Labor $0 Labor $0
Gas $9,427 Gas $300
Chemicals $0 Chemicals $0
Insurance $0 Insurance $0
Electricity $110,577 Electricity $3,519
Annual Equip. Repair $21,494 $684
PW Maintenance Costs $1,479,548
TOTAL ANNUAL COST $387,360
NOTE:All values adjusted to 2016 dollars
Year
Ending Population Served (1)
Average Day
Demand (1)
(MGD)
Average Day
Demand (1) (MGD)
Pumped
from
GSR
BHP Required
for Double
Pumping kWH kWH/Year
Average
kWH/Year
2016 23,544 2.57 1785 892.3 6.35 4.74 41,508
2020 25,032 2.73 1896 947.9 6.75 5.03 44,092 42,800
2025 28,299 (11)3.30 2292 1145.8 8.16 6.08 53,299 48,696
2030 31,566 (11)3.86 2680 1340.2 9.54 7.12 62,343 57,821
2035 34,833 (11)4.43 3076 1538.1 10.95 8.17 71,549 66,946
2040 38,100 (10)5.00 3472 1736.0 12.36 9.22 80,755 76,152
2066 38,100 (10)5.00 3472 1736.0 12.36 9.22 80,755 80,755
Ultimate 70,000 (14)7.75
Average 50-Year weighted kWH/year 70,378
Assume:TDH 30 ft Annual Additional Pumping Cost 3,518.92$
Efficiency 94%dual pumping to single pumping
Electricity $0.05 $/kWH
Annual Costs
GSR & Booster Station Project
SEH Peer Review
Capital & Maintenance Cost Estimate for 1.5 MG Ground Storage Reservoir & Booster Station
Rosemount, MN
50 Year Present Worth Calculations
Bid Alternates
Item Amount Difference
Base Bid - Magney $5,548,000
Alternate Bid A - Magney $5,338,000 $210,000
Alternate Bid B - Magney $5,211,000 $337,000
Alternate Bid C - Rice Lake $5,393,600 $154,400
Alternate Bid A & C - Rice Lake $5,093,600 $454,400
Alternate Bid B & C - Magney $5,096,000 $452,000
Potential Cost Savings Estimate
Peer Review
GSR and Booster Station Project
Rosemount, MN
Raised HGL
Unit. Wt.
Item Unit Qty.or Install Unit Cost Cost
Division 1 - General
Mobilization LS 1 $74,842 $74,842
Division 3 - Concrete
Walls CY 225 $800 $180,384
Division 31 - Earthwork
Bracing LS 1 $50,000 $50,000
Earthwork CY 12500 $6 $75,000
Division 33 - Tank
Change in Tank Height LS 1 $375,000 $375,000
Total $755,226
Potential Cost Savings Estimate
Peer Review
GSR and Booster Station Project
Rosemount, MN
Temporary Easement for Easier Buried GSR Construction
Unit. Wt.
Item Unit Qty.or Install Unit Cost Cost
Division 1 - General
Mobilization LS 1 $20,200 $20,200
Easement Cost LS 1 -$20,000 -$20,000
Division 31 - Earthwork
Bracing LS 1 $200,000 $200,000
Division 33 - Water Main
Temp Water Main LF 220 -$100 -$22,000
16" Water Main LF 220 $200 $44,000
Total $200,200
Potential Cost Savings Estimate
Peer Review
GSR and Booster Station Project
Rosemount, MN
Rectangular GSR w/ Integral Pumping Chamber and HSP Building
Unit. Wt.
Item Unit Qty.or Install Unit Cost Cost
Original Bid
Division 1 - General
Mobilization LS 1 $246,164 $246,164
Division 3 - Concrete
Walls CY 451 $800 $360,768
Base Slab CY 150 $700 $105,003
Floor Slab CY 112 $800 $89,413
Footings CY 17 $700 $11,673
Division 31 - Earthwork
Bracing LS 1 $250,000 $250,000
Earthwork CY 25000 $6 $150,000
Division 33 - Tank
Tank LS 1 $1,271,000 $1,271,000
Subtotal $2,484,022
Rectangular GSR Configuration
Division 1 - General
Mobilization LS 1 $221,470 $221,470
Division 3 - Concrete
Walls CY 607 $800 $485,600
Base Slab CY 825 $800 $660,000
Floor Slab CY 490 $800 $392,000
Pump Chamber CY 100 $800 $80,000
10% Additional CY 202 $800 $161,760
Division 31 - Earthwork
Bracing LS 1 $150,000 $150,000
Earthwork CY 14000 $6 $84,000
Subtotal $2,234,830
Total Difference $249,192
Potential Cost Savings Estimate
Peer Review
GSR and Booster Station Project
Rosemount, MN
1.25 MG GSR Tank
Unit. Wt.
Item Unit Qty.or Install Unit Cost Cost
Division 1 - General
Mobilization LS 1 $7,500 $7,500
Division 31 - Earthwork
Earthwork CY 1800 $6 $10,800
Division 33 - Tank
Change in Tank Height LS 1 $75,000 $75,000
Total $93,300
Potential Cost Savings Estimate
Peer Review
GSR and Booster Station Project
Rosemount, MN
Horizontal Centrifugal Pump Station
Unit. Wt.
Item Unit Qty.or Install Unit Cost Cost
Division 1 - General
Mobilization LS 1 $141,655 $141,655
Division 3 - Concrete
Walls CY 451 $800 $360,768
Base Slab CY 150 $700 $105,003
Division 7 - Thermal
Roof Hatches LS 1 $3,500 $3,500
Division 31 - Earthwork
Bracing LS 1 $250,000 $250,000
Earthwork CY 25000 $6 $150,000
Division 32 - Fencing
Ornamental LS 1 $18,500 $18,500
Division 33 - Tank
Change in Tank Height LS 1 $400,000 $400,000
Total $1,429,427
Potential Cost Savings Estimate
Peer Review
GSR and Booster Station Project
Rosemount, MN