1c Chg Order Well 9 Proj 97-4id..
MEMORANDUM
CITYOF
C HASSEN
J City CenterDrive, PO Box 147
;hanhassen, blinnesota 55317
Phone 612.937. I900
General Fax 612.937.5739
~gineedng Fax 612.937.9152
tblic Safety Fax 612.934.2524
(/eb www. d. chanhassen, mn.m
TO:
FROM:
DATE:
SUB J:
Todd Gerhardt, Acting City Manager
Anita L. Benson, City Engineer ~
January 19, 1999
Approve Change Order No. 1 for Well No. 8
Project No. 97-4
The purpose of this change order is to include the pump in the well drilling
contract rather than the well house construction contract as originally intended.
The desire to add the pump to the well drilling contractor's contract is based upon
the final well alignment test which was performed on November 25, 1998~ The
well alignment and plumbness are generally within the American Water Works
Association (AWWA) standards but exceed the project specifications for
alignment and plumbness. Although well alignment meets AWWA alignment
standards at the pump setting depth of 260 feet, it is possible that some amount of
pump column/well casing interference will result which could cause premature
pump Component wear.
During installation of the test pump which'has a 13.5-inch diameter bowl assembly,
a 10-inch diameter column pipe, and set to a depth of 300 feet, no excessive signs
of pump column/well casing interference were observed. Since the permanent
pump will be of similar size and set at a depth of 260 feet, the risk of premature
wear of the permanent line shaft vertical turbine pump is believed to be minimal.
However, in an effort to provide the City an added measure of financial protection,
the well drilling contractor has agreed to provide a five-year warranty consisting of
a two-year full warranty followed by a three-year limited warranty, with provisions
for removal and inspection of. the pump after five years of service. Typically,
routine maintenance is performed by the Utility Department on all well pumps on a
five-year basis. The extended warranty covers one pump pull, disassembly,
cleaning, inspection, replacement and/or repairs of any and all pump components
showing premature wear due to well casing/pump column interference at no cost
to the City and one pump reinstallation. If the pump were installed as originally
intended under the well house contract and if future problems with the pump were
to occur, the City could be left "holding the bag" while two contractors (driller and
pump installer) point fingers at each other. Approval of this change order will
provide the City sole source accountability for the well and pump.
This change order represents a price increase to the well construction contract of
$42,961. However, the corresponding reduction in well house bid prices is
expected as the pump has been eliminated from that contract. A comparison of
unit prices against bid prices obtained in January and February of 1998 for pump
repair projects with identical pump components was completed to insure
CiO' of Chanhassen. A g~vwing communi(7 with dean lakes, quality schools, ~ charming downtown,.thriving businesses, and beautiful parks. A great place to live. wor~, and play.
Todd Gerhardt
January 19, 1999
Page 2
competitive pricing of the components listed in this change order. The results o~
this comparison indicate that the Well No. 8 pump components compare favoral[ly
to the competitive bid prices obtained in 1998. Additionally, ~ well pump cost [
comparison was completed between the Well No. 7 pump which was comple, te~n
1996 and the Well No. 8 pump proposed for 1999 in this change order. Although
this is not an "apples to apples" comparison, many components ofboth pumps a~_~e
similar. The 1996 price for the Well No. 7 pump which was competitively bid v:~as
$46,000. The proposed change order price for the Well No. 8 pump is-$42,96t~
It is recommended that in exchange for the well alignment exceeding the specffi{d
limits, Change Order No. 1 which provides for a five-year warranty consisting ga
two-year full warranty followed by a three-year limited warranty, with Provisio~
for removal and inspection of the pump after five years of service, be approved ig
the total amount of $42,961. Again, this is work that has been eliminated from ~e
well pump house contract and simply added to the Well No. 8 drilling contract ~
through this change order. ·~ ~
Change Order No. 1
Attachment:
c: Dave Hempel, Assistant City Engineer
Charles Folch, Director of Public Works Operations
Phil Gravel, Bonestroo & Associates
John Hemming, Bonestroo & Assoeiates
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CITY OF CHANHASSI=N
CHANGE ORDER
CONTRACTOR
E.H. Renner & Sons, Inc.
ADDRESS
15688 Jarvis Street NW
Elk River, MN 55330
CHANGE ORDER NO.
1
DATE
January 8, 1999
PROJECT NO.
97-4
PROJECT NAME
Deep Well No. 8
SHEET
1OF 4
TYPE OF WORK
Water Supply Well
ORIGINAL CONTRACT AMOUNT
_$__2~0_6__,_~ 94.~0_0__
Spec.
No.
11219
Item
No.
Well Pump
Item of Work
Unit I Original±
Previous
Change
Quantity
LS 0
Net Increase to Date: $42,961
Quantity+
Unit
Pdce
42,961
Totals
Ir)crease
Amount
42,961
42,961
Decreas
e Amount
Due to this change, the contract time is extended to November 1, 1999.
EXPLANATION OF CHANGE 11'4 PLAN RECOMMENDED (Attach additional sheets if necessary) __
See Attached Sheets
CONTRACT-OR. NATL.'NAT E ~--~.. DATE
--i ........ -~-' ~~ .............. ' ' /-'" "'~'''- '~''~
C.TY EN.~INEER SI.~NATURE DATE
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EXPLANATION OF CHANGE IN PLAN
The well alignment and plumbness are generally within American Waterworks Association
(AWWA) standards but exceed the project specifications for alignment and plumbness.
Some amount of pump column / well casing interference will result, which could cause premature
pump component wear.
The original intent was to include the well pump in the "Deep Well No. 8 Pumping Facility"
construction contract.
It is recommended that the well pump be added to the well drilling construction contract for the
following reasons:
Due to the possibility of premature pump wear due to well misalignment, it is highly
desirable for the City to have sole-source accountability for the well and pump.
Due to the well alignment not meeting project specifications, this change order includes
provisions for an extended pump warranty, at no additional cost to the City. If the pump
were installed by the future well house Contractor, it would be difficult and / or expensive to
obtain an extended warranty for the well pump.
Although this change order represents a price increase in the well construction contract, a
corresponding reduction in well house bid prices will result, and the overall project costs will not be
changed.
WARRANTY
In accordance xvith the contract documents, all work covered by this change order shall be under full
warranty for a period of two years from the date of final acceptance by the Owner. The full
warranty period of two years shall be followed by an extended warranty period of three years, for a
total warranty period of five years from the date of final acceptance by the Owner. All work,
equipment, and materials under this change order is subsequently referred to as the "pump".
The following provisions are placed on the extended warranty, to be in effect after the two year full
warranty expires:
The pump shall be removed, brought to the Contractor's shop, disassembled, cleaned, and
inspected at no cost to the City.
Any and all pump components showing premature wear due to well casing / pump column
interference shall be replaced and / or repaired at no cost to the City.
The extended warranty is not intended to cover normal wear and tear. Repairs and
component replacement due to normal wear and tear shall be completed and paid for as
mutually a~eed upon at such time by the City and the Contractor. Repairs and component
replacement due to normal wear and tear after five years of service are to be expected.
Following inspection and repair work, the pump shall be re-installed and placed into service
at no cost to the City.
The Contractor shall pull the pump for inspection and maintenance after approximately five
years of service and prior to the extended warranty expiration date. The City may direct that
I:13931393481ctychngordrfrm. doc
the pump be pulled sooner than five years, based on operating conditions. The extended
warranty covers one pump pull, disassembly, cleaning, inspection, replacement and / or
repairs as listed under item 2 of this heading, and one pump reinstallation.
SPECIFICATIONS
A tabulation of pump components including specifications, manufacturers, and pricing is attached.
The pump design point is 1,300 gallons per minute, at 420 feet total dynamic head, at 1,760 rpm
with 87% pump bowl efficiency. The pump setting shall be 260 feet. The pump shall be run by an
adjustable frequency drive provided by others. The pump shall be capable of operation at speeds up
to 1,850.
Based on field performance testing as directed by the engineer, the pump shall operate within four
percent of the manufacturers stated pump efficiency and shall have a peak - to - peak vibration
amplitude of 2.0 mils or less.
SCHEDULE
The well pump should not be installed until the well house (by others) is substantially completed.
The substantial and final completion dates for the well house are September 15, 1999, and
November 1, 1999, respectively. It is anticipated that pump installation can begin on or around
September 15, 1999. The pump shall be fully installed, tested, and operational prior to November 1,
1999.
PRICE
A detailed price comparison to 1998 pump component bid prices and to the Well No. 7 pump bid
price was performed. This comparison indicated that the price of $42,961 is reasonable.
l:13931393481ctychngordrfrm, doc