RES 2022-0616 - Change Order No. 5 with Hawkins Construction Company for OPW 53517 - Improvements to Digester #1 in MoRiver WRRF C-25A
CITY OF OMAHA
LEGISLATIVE CHAMBER
Omaha,Nebraska
RESOLVED BY THE CITY COUNCIL OF THE CITY OF OMAHA:
WHEREAS, Hawkins Construction Company was awarded a contract by City Council
Resolution No. 647 on July 14, 2020, to construct OPW 53517, being the Improvements to
Digester#1 in MoRiver WRRF Project; and,
WHEREAS, it is necessary to increase the contract due to unforeseen conditions and
revisions; the specific changes are listed in the attached Change Order No. 5, which by this
reference is made a part hereof; and,
WHEREAS, Hawkins Construction Company has agreed to perform these services for a
total additional cost of $221,327.00, which is to be paid from the Sewer Revenue Improvements
Fund 21124, Capital Asset Replacement Program Organization 116913; Sewer Revenue Bonds
will be issued to finance this project.
NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF
OMAHA:
THAT, as recommended by the Mayor, Change Order No. 5 with Hawkins Construction
Company for additional work on OPW 53517, being the Improvements to Digester#1 in MoRiver
WRRF Project, is hereby approved.
BE IT FURTHER RESOLVED:
THAT, the Finance Department is authorized to pay an additional sum of$221,327.00, for
this change order, from the Sewer Revenue Improvements Fund 21124, Capital Asset
Replacement Program Organization 116913; Sewer Revenue Bonds will be issued to finance this
project.
3153tns APPROVED AS TO FORM:
10/7za-
CITY TORNEY (DATE
By
Councilmember
Adopted JUN 2 8 MIL 1 -D
K Allah
City C erk
Approved
Mayor
CONTRACT CHANGE ORDER
City of Omaha
Public Works Department
Plant Maintenance & Engineering Division
PROJECT NAME: DATE: 5/12/2022
Digesters 1 and 5 Cover Replacement CHANGE ORDER#: 5
OPW 53517
PROJECT LOCATION: STP/P.O.#: -
Missouri River WRRF BASE BID 5,925,377.00
CONTRACTOR: FUND: 21124
Hawkins Construction Company AGENCY: CARP
ORG.: 116913
ORDINANCE/RES NO.: 2020-064-7
DATE: 7/14/2020
NO. DESCRIPTION OF CHANGES DECREASE INCREASE
CPR 18 Upgrade PLC in Digester Control Complex $ 52,496.00
CPR 20 Purchase a spare motor for the linear motion mixers $ 3,558.00
CPR 21 Replace the Valves and Fire Hydrant on Potable Line $ 45,385.00
CPR 22 Electrical Code Compliance in Annexes $ 613.00
CPR 23 Replace bent pipe on suction line in digester 5 $ 9,096.00
CPR 24 Purchase Refurbished Linear Motion Mixer Drive $ 98,033.00
WCD 2 Repair Roof On Digester Control Building $966.00
WCD 3 Patch around pipes in the east sampling building $ 4,859.00
WCD 4 Patch cone to digester wall seam $ 6,321.00
WCD 5 Paint Pipes(there is no cost assocaited with this WCD) $ -
SUB-TOTAL DECREASE IN CONTRACT PRICE 0.00 N/A
SUB-TOTAL INCREASE IN CONTRACT PRICE N/A 221,327.00
NET DIFFERENCE 221,327.00
BASE BID PLUS PREVIOUS CHANGE ORDERS 7,088,930.00
REVISED CONTRACT PRICE 7,310,257.00
INCREASE/DECREASE 40 WORKING DAYS
5-12-22
ACCEPTED: / DATE:
Co 1'
Digitally signed
APPROVED: 0011-"^J Dbate 022 od5.12 DATE:
City Project and Cons' ucttti? ilaGifAer
APPROVED: i DATE:
5/25/22
Plant Engineering Manager 3/ z 0Z?
APPROVE . „ /1 ,rG DATE: -� 'a!_
APPROVED: DATE: 3-`' S f - `�-
Oµnxn.Ns
MEMORANDUM OgAreD pEBRV�P;
OPW 53517 — Digesters 1 and 5 Cover Replacement — Change
Order #5 Executive Justification
TO: Bob Stubbe
FROM: Jake Hansen,
DATE: May 26th 2022
Purpose
The purpose of this memorandum is to provide justification for the Change Order#5 to OPW
53517
Project Overview
89%of the cost of this change order is due to three CPRs: CPR 18 Upgrade the PLC system;
CPR 21 Change valves on the potable water line; and CPR 24 Purchase a refurbished linear
motion mixer (LMM) drive. The PLC upgrade needed to happen in order to increase the
number of inputs in the PLC so new sensors can be incorporated as requested by the
operations staff. The valves and hydrants on the potable line needed to be changed out
since we have had several ruptures on this line and it was very difficult to isolate sections of
the pipe during the repair. We purchased a spare LMM drive because we will eventually
have LMM's on all digesters—two in the current project (53517); two in upcoming
construction project (53525) and one in a future project. Currently, the lead time on a new
drive unit is several months. Having a spare reduces the downtime of the digesters.
Change Order Costs
$221,327.00
Project Construction Costs
This change order increases the base bid of$5,925,377.00 by 3.7%.
Recommendation
I recommend proceeding with the Change Order for the following reasons:
• The additional monitoring allowed by the new PLC system should help to reduce
downtime and allow us to maximize our digester methane production.
• The potable line system is needed for cooling and sealing pumps at the Monroe
Pump Station. This station is currently being set up for bypass pumping under OPW
53082; therefore, this is an ideal time to complete this work.
• If we lose a linear motion mixer for several months, we will not have adequate
treatment of our biosolids and would not be able to land apply it.
1i0 A,�R J.
Cyr
°R-rPD FF11511 ry
MEMORANDUM
OPW 53517 - Digesters 1 and 5 Cover
Replacement - Change Order No. 05
Justification
TO: Jake Hansen
COPIES: Amit Shrivastava Mike
Arends
FROM: Josh Dodson
DATE: May 26,2022
The purpose of this memorandum is to provide background and justification for the Change
Proposal Requests(CPRs)and Work Change Directives (WCDs)in Change Order No. 05.
Overview
MRWRRF operations staff has requested a number of changes/upgrades as we near the end of
construction on the digester 1 and 5 project. These changes/upgrades relate to additional purchases for
spare units and preventative maintenance activities.
Justification
The majority of the change order price($193,622.00 of the$221,327.00)is tied to three separate CPRs
described in detail below.
CPR 18, PLC upgrade: The Program Logic Control System 9 in the digester control complex is over
two decades old and we did not have enough additional slots left for inputs requested by our
operations staff. These additional I/Os will allow us to monitor the current and temperature of the
new linear motion mixers and monitor the flow and chemical composition of the gas generated from
our digesters. The linear motion mixer operation has been problematic and we anticipate that this
additional monitoring will allow us to detect problems early on. The gas flow meters will allow us to
better understand our gas production which will help in planning future expansions and optimize
energy production when we burn the gas in our engines. The cost of this work is $52,496.00. The
City and HDR have reviewed the costs and believe they are reasonable.
CPR 21, Replace the valves and fire hydrants on the potable water line. The staff intends to replace
the valves on the main potable line that runs to the southern end of our facility. We have experienced
several ruptures on this line and we wanted to take the opportunity to replace the valves and hydrants
while the Monroe Lift Station construction project is setup for bypass pump operations and would be
completely reliant on the potable water for sealing the bearings and cooling the pumps. The cost of
this work is $45,385.00. The City and HDR have reviewed the costs and believe they are reasonable.
Hawkins construction is the contractor on both of these contracts and this work would be best
completed under the digester 1 and 5 project.
CPR 24, Purchase Refurbished Linear Motion Mixer Drive. We previously purchased a linear motion
mixer (LMM) system in CPR 16 for digester #5 and received the unit earlier this year. When we
experienced a number of technical issues with the drive system on the LMM for digester 1, Ovivo
(manufacturer of the LMM) told us to switch out the drive system on that unit with the new drive that
was reserved for digester 5. Ovivo shipped the damaged drive back to their shop to analyze the
1 of 2
failures and refurbish the unit. We purchased this refurbished drive at a reduced cost as a spare
because of the long lead times we have seen with Ovivo's products. In addition, these drive units
appear to have the highest probability of failure. MRWRRF intends to have LMM's on all 5 digesters
eventually and having a spare drive reduces the downtime of the digesters. The cost of this unit is
$98,033.00. The City and HDR have reviewed the costs and believe they are reasonable.
The remainder of the CPRs and WCDs are for spare units and needed remediation due to conditions
discovered during construction.
Hawkins has already executed all of these CPRs and WCDs. This was necessary in order to acquire
material ahead of time to ensure that construction was not delayed due to on-going supply chain
issues.
2 of 2