1f. Contract amendment No 1 for Well no. 5 II i CHANHASSEN
CITY OF 1........
, :.--10. ''1 ;411/4, .
.. 690 COULTER DRIVE • P.O. BOX 147• CHANHASSEN, MINNESOTA 55317
I (612)937-1900 • FAX(612)937-5739 Actin t; CI: M.,: ,--`,,;
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MEMORANDUM li -,K: .._w—_..._.-,.M,
I
TO: Don Ashworth, City Manager c:: ,,...1_l , a_. .
D?i'. S;t•... to L;'.,-.SSi n
I FROM: Gary Warren, City Engineer
' kS--
DATE: October 31, 1990
___/1/s'l q4._
1 SUBJ: Approve Contract Amendment No. 1 for Well No. 5 Construction
Project No. 89-4A
IIWell No. 5 which was constructed this summer has recently been
placed into operation. In order to replace a malfunctioning
I check valve on Well No. 2 and to :protect_t.he system from "water
hammer" resulting from system pressure fluctuations, it is
necessary to install a surge tank and check valve apparatus on
II the discharge line from Well No, 2. This will operate to dampen
out any system pressure fluctuations .and includes a new
wafer-type check valve which will protect the mechanical parts of
• the pumping mechanism and the distribution piping. The enclosed
II contract amendment for $5 ,957 is for construction of these
modifications.
II It is recommended that the City Council `'accept Contract Amendment
No. 1 in the amount of45 ,957 for installation of the surge tank
and check valve as described in the attachments and that the
contract ceiling be adjusted to reflect this change to a new
IItotal of $94,200.
ktm .::M.,x
IIAttachment: Contract Amendment No. 1
II
I
ICHANGE ORDER
IOrder No. 1
Date 9-27-90
I
Agreement Date 5-2 2-9
gr 5-22-90 T.p.44 S1 4-i4
IName of Project: Construction of Well No. 5 , watermain
and controls .
Owner: r i r o f rr
y nhas�An, Minnesota - -
IContractor: BergPrson - Ca swP 1 1 . Tnr.
I The following changes are hereby made to the Contract Documents:
Furnish and install surge tank on well number . See
Attached proposal .
IJustification:
City' s request
1 Change to Contract Price: $ 5 , 957.00
CITY OF CHANHASSEN
I Original Contract Price: $ 88 , 243 . 00
THEM
OCT 19 1990
I Current Contract Price adjusted
by previous Change 0 Order: $ 88 , 243 .00 ENGINEERING DEPT.
1 _•
The Contract Price due to this Change Order will be (increased)
to . -17 , $ 94, 200.00
I
The date for completion of all work will be December 1 , 1990
I (Date)
Contractor En ineer Owner
IB By: et_ A 114.-
Date:// -/7-9 o Date: (C- IS -'1C) D 411P 1‘ °1,0
i
-- CO-1
I
- • ~ . ^__ — . ' ~-
•
•
-o: Jim Bullert Datc!: 9/7/90
Druce A' Lzeech Associate.lz N�
\
From: John Gilbertson Job: Chanhassen #5
Bergerson-Caswell ' Inc. 111
RE: Chanhassen Well *5
Suroe, tarf- and check valve modifications 111
Furnish and install surge tank, 10-inch wafer typm check valve, long
radius bend, 10-inch piping modifications, two (2) pipe support,, at ' N�
tank and L. H. bend, painting, concrete work.
Your cost is: 5-9Z- N�
'- -
METHOD OF OPERATION
Upon well start-up air filling column is forced by the rising water 11
against the closed check valve into the air surge ta.nk. When air tank
is full of air and water pressure has built up to system operation
pressure, the check valve opens allowing water to flow into N�
distribution system. While pump is operations, any system pressure
fluctuations seen at the well will be dampened by the surge tan� '
On shut down, the checl: valve closes on loss of pump pressure' the 0�
well begins to drain water filling column back into well . The bror`ze
check valve on surge tank opens allowing air to enter surge tank and
column piping. N�
Pump shall have a delay on the column piping to drain before restarting
of the pump. this delay circuitry will be in the pump control panel - N�
No electric modifications are included in cost shown above.
cc: jg\bulIert' lJg .
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memo ot pages.
Post-Ir brand tax transrm '
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I B• eveA/se24-1=Ca4,effieitilic . • .
I ''`:i li; ` " i*:;. .*fr,y 5115 Industrial Street
Maple Plain,Minnesota 55359
(612)4794121
I
THREADED BOSS—, BRONZE CHECK VALVE
� /// .//////
I 4 , f t STANDARD WEIGHT GALV•
CEILING -4 tin. ,r`—'Z--� PIPE a SCRENEC FITTINGS.
I
' ALUMINUM OR BRONZE
INSECT SCREEN 8AG
I ..— ---STEEL TANK CCr1STRUC'E0 IN
1 CONFCRMAtrCE WITH ASME
CODE FOR 150 PSI. WCRKING
PRESSURE. 30e/x. ,5 0,/i
CEILING
Vied::Y HEIGHT
_ TANK HE. O.
I f SCHEDULE STEEL PIPE
! /�WITH l2. LB. FLANGE WELDED
DE0
6. I --10" TO T NK.
.
It _ m 1 i�_ j _ /er"EXA1T/A%4
11r III" PUMP CISCHARGE PIPING
w r,. __, III �i �Y CTAEAG.
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OiSCHARGE I
Ili 1
�: � �� HEIGHT j I 'N —MOUNTING TEE a SUPPORT r
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I i /-- FLOOR
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I .
IWELL DRILLING AND REPAIRING PUMP INSTALLATION AND SERVICE
MUNICIPAL - INDUSTRIAL L, DOMESTIC - ANY SIZE • ANY DEPTH