HomeMy WebLinkAbout2.a. Discussion of Estimated Cost Increases for the 1.5 Million Gallon Ground Storage Reservoir and Booster StationI:\City Clerk\Agenda Items\Approved Items - Special Work Session\2.a. Discussion of Estimated Cost Increases for the 1.5 Million Gallon Ground Storage
Reservoir and Booster Station, Engineering Project 179.docx
EXECUTIVE SUMMARY
City Council Work Session: January 5, 2016
AGENDA ITEM: Discussion of Estimated Cost Increases
for the 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.a.
ATTACHMENTS: Cost comparison Table 1 and Table 2 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. WSB has recently developed updated cost
estimates for the project and the estimated cost of the project has increased significantly since last April
when WSB prepared preliminary cost estimates as a part of the “Rosemount Water Storage Capacity
Evaluation”. This report examined several options to provide water supply and storage including a fluted
column style water tower, a composite style water tower and the Ground Storage/Booster Pumping
Station presently being implemented. This report indicated a preliminary estimate for the Ground
Storage/Booster Pumping Station of $4,138,000 and a line item has been included in the 2016 capital
budget for this expense.
With the completion of final project plans and specifications, the updated estimate for the Ground
Storage/Booster Pumping Station now stands at $6,028,281. This is a cost increase of $1,890,291 over the
April 2015 preliminary estimate. Approximately $380,000 was discussed with the council at the October
9th Council Work Session with the option for a completely buried roof, but this estimate did not include
the additional earth work that is required for constructing a completely buried roof tank (approximately
75% of the structural cost of the tank compared to 50% for a domed tank). The detail of the estimated
cost increase components is contained on the attached Table 1. The major cost increase components are
$1,092,000 for the tank structure and associated site work, $338,000 for site work not associated with the
Ground Storage Reservoir and $328,000 for additional structural components necessary for the very deep
booster station structure.
WSB has developed an alternate bidding strategy that may result in a savings of $935,000 for the project.
This alternate would consist of bidding a domed roof tank as an option to the base bid completely buried
tank estimating a savings of $755,000. Additionally, submitting the process equipment and materials
(pumps, piping, concrete for tanks, etc.) for sales tax rebates produces an estimated savings of $180,000.
The detail of the estimated cost components of this alternative are contained in the attached Table 2.
2
The project is important for the accommodation of future growth within the city of Rosemount. The 1.5
million gallons (MG) of ground storage and a 6,000 gallon-per-minute (gpm) pumping station could
provide adequate storage and fire protection for future development out to 2025. Additionally, the ground
storage reservoir will allow for the mixing of well water from various sources to help ensure radium levels
are in compliance with United States Environmental Protection Agency (EPA) requirements. Lastly, the
ground storage reservoir could also serve as a finished water clearwell and pumping station for a future
water treatment plant if constructed at this site. Investing in these improvements at this time could
significantly reduce the future cost of the water treatment plant since these major components of the plant
would already be completed prior to the plant construction.
On December 15, 2015, the City Council received plans and specifications and authorized the advertising
for bids for the 1.5 Million Gallon Ground Storage Reservoir and Booster Station. Prior to proceeding
with bidding, a discussion is warranted with the council regarding the expected cost increase to be received
with the project bidding. According to discussions with Rosemount Finance staff, the funding for the
project will come from water utility revenue bonding. The bond sale can be adjusted to accommodate the
expected cost increase with payments coming from future water utility revenue. The bond proceeds will
be repaid using equal payments from the water utility fund and the water core fund.
Staff recommends that the project move forward to bidding and that the bidding documents are prepared
with a base bid for the completely buried tank and an alternate bid to construct the tank with the domed
roof. Based upon the bids received, staff will make a recommendation to the City Council to move
forward with the most cost effective project.
SUMMARY:
Staff wishes to initiate a discussion regarding recent cost estimate increases for the 1.5 Million Gallon
Ground Storage Reservoir and Booster Station, Engineering Project 179 and recommends that the
bidding process proceed with an alternate bid consideration for a domed roof tank
Ro
s
e
m
o
u
n
t
1.
5
MG
Gr
o
u
n
d
St
o
r
a
g
e
Re
s
e
r
v
o
i
r
an
d
Bo
o
s
t
e
r
Station
En
g
i
n
e
e
r
'
s
Op
i
n
i
o
n
of
Pr
o
b
a
b
l
e
Co
s
t
(S
t
u
d
y
Ph
a
s
e
ve
r
s
u
s
Fi
n
a
l
Design Phase)
It
e
m
St
u
d
y
Op
i
n
i
o
n
of
Pr
o
b
a
b
l
e
Co
s
t
(A
p
r
i
l
29
,
20
1
5
)
Fi
n
a
l
De
s
i
g
n
Op
i
n
i
o
n
of
Pr
o
b
a
b
l
e
Co
s
t
(D
e
c
e
m
b
e
r
15
,
20
1
5
)
In
c
r
e
a
s
e
in
Co
s
t
Explanation
1
Di
v
i
s
i
o
n
s
1 an
d
1 ‐
Ge
n
e
r
a
l
Co
n
d
i
t
i
o
n
s
,
bu
i
l
d
i
n
g
pe
r
m
i
t
s
,
bo
n
d
s
,
in
s
u
r
a
n
c
e
,
mo
b
i
l
i
z
a
t
i
o
n
,
pr
o
j
e
c
t
ma
n
a
g
e
m
e
n
t
,
su
p
e
r
i
n
t
e
n
d
e
n
t
,
an
d
co
n
t
r
a
c
t
o
r
pr
o
f
i
t
In
c
l
u
d
e
d
in
It
e
m
No
.
10
be
l
o
w
$2
7
4
,
0
0
0
$2
7
4
,
0
0
0
These costs were part of the contingencies cost item in the study cost estimate (see Item No. 10)
2
1.
5
MG
Bu
r
i
e
d
Gr
o
u
n
d
St
o
r
a
g
e
Re
s
e
r
v
o
i
r
an
d
As
s
o
c
i
a
t
e
d
Si
t
e
Wo
r
k
$1
,
4
6
0
,
0
0
0
$
2
,
5
5
2
,
0
0
0
$
1
,
0
9
2
,
0
0
0
The City Council reviewed changing from a partially buried dome tank to a completely buried flat roof tank which accounts for $755,000 of this cost increase for the tank and additional earth work. The tank structure cost increased by $380,000 and the earth work cost increased by $375,000 for a completely buried tank.
3
Si
t
e
Wo
r
k
No
t
As
s
o
c
i
a
t
e
d
wi
t
h
Gr
o
u
n
d
St
o
r
a
g
e
Re
s
e
r
v
o
i
r
$2
5
0
,
0
0
0
$
5
8
8
,
0
0
0
$
3
3
8
,
0
0
0
The study cost estimate did not fully account for the very tight site conditions and the need to move dirt around the site multiple times due to the closeness between the ground storage tank and booster station. Upon final survey of the site and adjacent facilities, the site is more constrained than originally anticipated in the Comprehensive Water Supply Plan.
4
Bo
o
s
t
e
r
St
a
t
i
o
n
St
r
u
c
t
u
r
a
l
$3
5
0
,
0
0
0
$
6
7
8
,
0
0
0
$
3
2
8
,
0
0
0
The size of the booster station and pumping chamber were increased in size to allow space for the future filter backwash pump for the future water treatment plant. In addition, the structural engineer calculated that the thickness of the pumping chamber walls to be 2 ‐2.5 feet thick due to the depth of the pumping chamber.
5
Bo
o
s
t
e
r
St
a
t
i
o
n
Ar
c
h
i
t
e
c
t
u
r
a
l
an
d
Co
a
t
i
n
g
s
$2
5
0
,
0
0
0
$3
4
8
,
0
0
0
$9
8
,
0
0
0
The size of the booster station building was increased in size to allow space for the future backwash pump for the future water treatment plant. The study cost estimate did not include all of the architectural components (fancy brick façade to match Fire Station No. 2, etc.) that were included with the final design.
6
Bo
o
s
t
e
r
St
a
t
i
o
n
Pr
o
c
e
s
s
$3
5
0
,
0
0
0
$4
2
0
,
0
0
0
$7
0
,
0
0
0
The final design includes several large interior and exterior valves and a 24 ‐inch bypass pumping line that were not included in the study cost estimate as the study did not include a preliminary site plan design and drawing.
7
Bo
o
s
t
e
r
St
a
t
i
o
n
Me
c
h
a
n
i
c
a
l
$1
5
0
,
0
0
0
$2
1
3
,
0
0
0
$6
3
,
0
0
0
Additional mechanical ventilation and cooling systems were required for the larger sized booster station building which were not included in the study cost estimate.
8
Bo
o
s
t
e
r
St
a
t
i
o
n
El
e
c
t
r
i
c
a
l
(i
n
c
l
u
d
e
s
ge
n
e
r
a
t
o
r
)
$5
0
0
,
0
0
0
$6
7
5
,
0
0
0
$1
7
5
,
0
0
0
The study cost estimate included $150,000 for the cost of the emergency generator as the pump horsepowers and other electrical loads had not yet been determined. The final design cost estimate included $275,000 for a 1000 kW diesel generator.
9
Co
n
s
t
r
u
c
t
i
o
n
Al
l
o
w
a
n
c
e
$0
$
5
0
,
0
0
0
$
5
0
,
0
0
0
A construction allowance was included in the final design bidding documents for addressing minor changes made during construction. This allowance can be removed from the bidding documents if requested.
10
Co
n
t
i
n
g
e
n
c
i
e
s
$3
3
1
,
0
0
0
I
n
c
l
u
d
e
d
in
It
e
m
No
.
1 ab
o
v
e
‐$3
3
1
,
0
0
0
The contingencies in the final design cost estimate are included in Item No. 1.
11
E
n
g
i
n
e
e
r
i
n
g
,
Le
g
a
l
,
Ad
m
i
n
$4
9
7
,
0
0
0
$
2
3
0
,
2
9
1
‐$2
6
6
,
7
0
9
Engineering fees include design, bidding, and phase construction services. The fees for WSB and its subconconsultants account for 3.82 percent of the total estimated construction cost.
To
t
a
l
Pr
o
j
e
c
t
Co
s
t
$4
,
1
3
8
,
0
0
0
$
6
,
0
2
8
,
2
9
1
$
1
,
8
9
0
,
2
9
1
De
c
e
m
b
e
r
17
,
20
1
5
TA
B
L
E
1
Ro
s
e
m
o
u
n
t
1.
5
MG
Do
m
e
Ro
o
f
Gr
o
u
n
d
St
o
r
a
g
e
Re
s
e
r
v
o
i
r
an
d
Booster Station
En
g
i
n
e
e
r
'
s
Op
i
n
i
o
n
of
Pr
o
b
a
b
l
e
Co
s
t
(S
t
u
d
y
Ph
a
s
e
ve
r
s
u
s
Fi
n
a
l
Design Phase)
It
e
m
St
u
d
y
Op
i
n
i
o
n
of
Pr
o
b
a
b
l
e
Co
s
t
(A
p
r
i
l
29
,
20
1
5
)
Fi
n
a
l
De
s
i
g
n
Op
i
n
i
o
n
of
Pr
o
b
a
b
l
e
Co
s
t
(D
e
c
e
m
b
e
r
15
,
20
1
5
)
Po
t
e
n
t
i
a
l
Cost Savings
wi
t
h
a 1.5 MG Dome Roof
Gr
o
u
n
d
Storage ReservoirPotential Cost Savings with a State Sales Tax Rebate on the Process Equipment and MaterialsFinal Design Opinion of Probable Cost with Potential Savings
1
Di
v
i
s
i
o
n
s
1 an
d
1 ‐
Ge
n
e
r
a
l
Co
n
d
i
t
i
o
n
s
,
bu
i
l
d
i
n
g
pe
r
m
i
t
s
,
bo
n
d
s
,
in
s
u
r
a
n
c
e
,
mo
b
i
l
i
z
a
t
i
o
n
,
pr
o
j
e
c
t
ma
n
a
g
e
m
e
n
t
,
su
p
e
r
i
n
t
e
n
d
e
n
t
,
an
d
co
n
t
r
a
c
t
o
r
pr
o
f
i
t
In
c
l
u
d
e
d
in
It
e
m
No
.
10
be
l
o
w
$2
7
4
,
0
0
0
$274,000
2
1.
5
MG
Bu
r
i
e
d
Gr
o
u
n
d
St
o
r
a
g
e
Re
s
e
r
v
o
i
r
an
d
As
s
o
c
i
a
t
e
d
Si
t
e
Wo
r
k
$1
,
4
6
0
,
0
0
0
$2
,
5
5
2
,
0
0
0
$755,000 $80,000 $1,717,000
3
Si
t
e
Wo
r
k
No
t
As
s
o
c
i
a
t
e
d
wi
t
h
Gr
o
u
n
d
St
o
r
a
g
e
Re
s
e
r
v
o
i
r
$2
5
0
,
0
0
0
$5
8
8
,
0
0
0
$19,000 $569,000
4
Bo
o
s
t
e
r
St
a
t
i
o
n
St
r
u
c
t
u
r
a
l
$3
5
0
,
0
0
0
$
6
7
8
,
0
0
0
$
4
5
,
0
0
0
$
6
3
3
,
0
0
0
5
Bo
o
s
t
e
r
St
a
t
i
o
n
Ar
c
h
i
t
e
c
t
u
r
a
l
an
d
Co
a
t
i
n
g
s
$2
5
0
,
0
0
0
$
3
4
8
,
0
0
0
$348,000
6
Bo
o
s
t
e
r
St
a
t
i
o
n
Pr
o
c
e
s
s
$3
5
0
,
0
0
0
$
4
2
0
,
0
0
0
$
2
8
,
0
0
0
$
3
9
2
,
0
0
0
7
Bo
o
s
t
e
r
St
a
t
i
o
n
Me
c
h
a
n
i
c
a
l
$1
5
0
,
0
0
0
$
2
1
3
,
0
0
0
$213,000
8
Bo
o
s
t
e
r
St
a
t
i
o
n
El
e
c
t
r
i
c
a
l
(i
n
c
l
u
d
e
s
ge
n
e
r
a
t
o
r
)
$5
0
0
,
0
0
0
$
6
7
5
,
0
0
0
$
8
,
0
0
0
$
6
6
7
,
0
0
0
9
Co
n
s
t
r
u
c
t
i
o
n
Al
l
o
w
a
n
c
e
$0
$
5
0
,
0
0
0
$50,000
10
Co
n
t
i
n
g
e
n
c
i
e
s
$3
3
1
,
0
0
0
I
n
c
l
u
d
e
d
in
It
e
m
No
.
1 ab
o
v
e
Included in Item No. 1
11
E
n
g
i
n
e
e
r
i
n
g
,
Le
g
a
l
,
Ad
m
i
n
$4
9
7
,
0
0
0
$
2
3
0
,
2
9
1
$230,291
To
t
a
l
Pr
o
j
e
c
t
Co
s
t
$4
,
1
3
8
,
0
0
0
$6
,
0
2
8
,
2
9
1
$755,000 $180,000
$
5
,
0
9
3
,
2
9
1
De
c
e
m
b
e
r
27
,
20
1
5
TA
B
L
E
2