1i. Approve Quotes for Security Contract for Water Treatment Plant, Proj. 04-08
CITY OF
CHANHASSEN
7700 Market Boulevard
PO Box 147
Chanhassen, MN 55317
Administration
Phone 952.2271100
Fax: 952.227 1110
Building Inspections
Phone 952.2271180
Fax 952.2271190
Engineering
Phone 952.227 1160
Fax 952.227 1170
Finance
Phone 952.227 1140
Fax 952.227 1110
Park & Recreation
Phone 952.227 1120
Fax 952.227 1110
Recreation Center
2310 Coulter Boulevard
Phone 952.2271400
Fax 952.2271404
Planning &
Natural Resources
Phone 952.2271130
Fax 952.2271110
Public Works
1591 Park Road
Phone 952.2271300
Fax 952.2271310
Senior Center
Phone 952.227 1125
Fax 952.227 1110
Web Site
www.ci.chanhassen.mn.us
1~
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MEMORANDUM
TO:
Todd Gerhardt, CIty Manager f!)
Paul Oehme, Dlf. of PublIc Works/CIty EngIneer? I
O/~
FROM:
DATE'
August 14,2006
SUBJ:
East Water Treatment Plant: Approve Change Order No.2 for
ModIficatIOns to Well Nos. 2, 5, and 6 - Project No. 04-08
REQUESTED ACTION
Approve Change Order No.2 for Improvements to Well Nos. 2,5 and 6.
BACKGROUND
On December 12,2005, City CouncIl approved Change Order No.1 deductIon In
the amount of $63,391.25 from the Water Treatment Plant Contract.
DISCUSSION
Well Nos. 2, 5 and 6 electncal system will need to be modIfied to allow the well
water to be pumped to the water treatment plant. Also, an electncal component,
VFD (Variable Frequency Drive) for new Well No. 10 should be modified based
on the pumping data and groundwater modelIng. The VFD for Well No. 10 is
located in the water treatment plant.
Well Nos. 2, 5 and 6 currently pump directly Into the dIstnbutIOn system (see
map). The statIc pressure or "head condition" in the distribution system IS much
greater than the pressure needed to pump the water to the water treatment plant.
The pumpIng specifications of the well pumps should be modIfied to compensate
for the change in head condition. If the well pumpIng specificatIOns were not
modIfied, the aquifer would be drawn down to unacceptable levels.
Staff and the City's consultant, KaedIng and Associates, Inc, have revIewed
several optIOns to modIfy the well specificatIOns to the new head condItIOns.
They included replaCIng or modIfYIng pumps, replacing the motors and changing
the electncal components for the wells. Changing or adding the electrical
components was shown to be the most cost effective approach. SpeCIfically,
changIng or addIng VFD's to wells was found to be the most cost effectlve.
VFD's are standard eqmpment on all new wells the City has constructed recently,
IncludIng Well Nos. 10 and 11. VFD's are hke dImmer SWItches for hghts. They
allow an electnc motor to be run at varYIng, rotatIOnal speeds. Without VFD's,
motors run at only one speed.
The City ot Chanhassen · A growing community with clean lakes, quality schools, a charming downtown, thriving businesses, winding trails, and beautiful parks. A great place to live, work, and play
Todd Gerhardt
WTP Change Order No.2
August 14,2006
Page 2
The existing wells do not have drawdown monitors. Drawdown monitors
constantly monitor the aquifer levels and send the information back through the
SCADA system to the controller. All new wells that the City has drilled recently
have drawdown monitors, including Well Nos. 10 and 11. Currently, staff has to
physically lower a drawdown mom tor into Well Nos. 2, 5 and 6 to find out the
level of the aquifer. With the addition of Well No. 11 in close proximity to Well
Nos. 2, 5 and 6, aquifer levels should constantly be monitored. Drawdown
monitors should be installed at the existing wells at this time.
Kaeding and Associates, Inc. has produced detailed specifications and drawings
for the work. Also, the consultant, staff and the contractor have reviewed the
scope of the work on site to ensure no work was missed.
In general, the scope of the change order work includes:
1. Furnish and install a new VFD at Well No.2 and convert the well to
variable-speed operation.
2. Install a VFD (previously intended for Well No. 10) at Well No.5 and
convert the well to variable-speed operation.
3. Furnish and install a larger VFD for Well No. 10 to be installed In the
water treatment plant.
4. FurnIsh and install aquifer draw down monitors on Well Nos. 2, 5 and 6
and connect a sensor to the SCADA system.
5. SCADA revisions for variable speed operations for wells.
6. Electrical modifications or removals at wellhouses necessary for
improvements, which also include removal of electrical chemical feed
equipment.
7. Electrical circuitry improvements for City-installed air conditioning
system.
8. Upgrade Wellhouse No.6 main conductors to comply with NEC and to
accommodate the combined load of Well Nos. 6 and 11.
To save on costs, staff will be responsible for the following work:
1. Remove interior walls for Wellhouse No.6.
2. Remove chemical feed equipment, tanks and piping from Wellhouse No.2
and 6.
Todd Gerhardt
WTP Change Order No.2
August 14,2006
Page 3
3. Remove Well house No.6 chemical room exhaust fan, intake louver,
dampers and ductwork and patch openings.
4. Remove Wellhouse No 6 chemical room sprinkler system and associated
pIpIng.
5. Furnish and install splIt air conditioning system for Wellhouse No.6.
Staff had originally envisioned this work to be separate from the water treatment
plant contract. However, the work has become more complex and costly then
originally planned. Due to the tight schedule for the water treatment plant and the
staging for connecting the wells to the treatment plant, this work should be
coordinated and managed by the water treatment plant prime contractor.
The change order cost for all Improvements is $120,035.00. Kaeding and
Associates, Inc. has reviewed the change order costs and finds it acceptable. The
budgeted amount for this work in the 2006 CIP was $70,000. Funding for the
project is 100% from the Water Utility Fund.
The security system and the fiber optic contracts for the water treatment plant are
both under budget. Both of these projects were paid for by the Water Utility
Fund. The security system contract is under budget by $20,242, and the fiber
optic contract, which was approved by Council on April 10, 2006, is under budget
by $21,567. If all three of the projects (change order for Well Nos. 2, 5 and 6,
security system and fiber optic contract) were combined, the net difference would
be $8,226.00 over the budgeted amount.
Staff is requesting the change order be approved at this time.
Attachment
g:\eng\public\04-08 wtp\bkgd 081406 approv co wells 256.doc
I
Capital Improvement Program
City of Clumhossen, MN
2006 thru 2010
Account # 1 700-0000-4530
Account # 3
Contact Unassigned
Department Water System Improvements
Type Improvement
Useful Life Unassigned
Category Utilities
Priority n/a
Project #
W-032
Project Name Well Rehabilitation Program
Account #2
Description I
This program annually inspects and performs regular maintenance of the City's wells. Well pumps are recommended to be serviced every 8 years.
Total Project Cost $175,000
Justification
I
To extend the life and ensure reliability of the City's well fields. Performing regular maintenance will extend the life of well components, reduce emergency calls
and have a more reliable water supply system.
Expenditures
Maintenance
2006
70,000
Total 70,000
. 2007
2008
35,000
35,000
2009
35,000
35,000
2010
35,000
35,000
Total
175,000
175,000
Funding Sources
Water Utility Fund
2006
70,000
Total 70,000
2007
2008
35,000
35,000
2009
35,000
35,000
2010
35,000
35,000
Total
175,000
175,000
Operational Impact/Other I
147
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August 9, 2006
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