6.1 West WWTF Project Change Orders
Request for
City Council Action
DEPARTMENT INFORMATION
ORIGINATING DEPARTMENT REQUESTOR: MEETING DATE:
Utilities Utility Manager Neidermeier March 25, 2024
PRESENTER(s) REVIEWED BY: ITEM #:
AE2S Engineer Schaefer
AE2S Engineer Schaefer
City Administrator/Finance Director Flaherty
6.1 – West WWTF Project
STRATEGIC VISION
MEETS: THE CITY OF OTSEGO:
Is a strong organization that is committed to leading the community through innovative communication.
X Has proactively expanded infrastructure to responsibly provide core services.
Is committed to delivery of quality emergency service responsive to community needs and expectations in a
cost-effective manner.
Is a social community with diverse housing, service options, and employment opportunities.
Is a distinctive, connected community known for its beauty and natural surroundings.
AGENDA ITEM DETAILS
RECOMMENDATION:
City Staff is recommending that the Council approve Change Order Proposals 32 and 33 from Rice Lake Construction
Group for the West WWTF project.
ARE YOU SEEKING APPROVAL OF A CONTRACT? IS A PUBLIC HEARING REQUIRED?
No No
BACKGROUND/JUSTIFICATION:
As the project proceeds to the final structures, geotechnical (soils) challenges were encountered in two areas.
The effluent (cascade) aeration structure encountered unanticipated groundwater during excavation. To avoid placing
concrete onto wet ground, the area was over-excavated and then brought to the appropriate grade with imported rock
material to allow for groundwater pumping. This additional work resulted in a net increase of $4,706 via Change Order
Proposal 32.
A more significant soil issue was encountered at the Administration Building location. The design-phase soil borings had
indicated the presence of approximately one foot of “soft” soil, which would be removed via top-soil stripping. As
excavation for the Administration Building proceeded, more extensive soft soil was encountered with an estimated
average additional soft soil layer of approximately six feet. The City-contracted geotechnical engineer (Braun Intertec)
investigated the excavation along with three additional “test pits” and recommended “soil correction”. Two approaches
were considered:
▪ Removal of soft soil (hauled off-site) and replacement with imported sand – initial estimate of approximately
$350,000, which does not include costs associated with potential groundwater mitigation. “Pockets” of sand and
groundwater were encountered during the test pit excavations observed by Braun.
▪ Modify the foundation approach to rammed aggregate piers. This is a proprietary approach, and we are working
with the Minnesota-licensed supplier of the technology for Geopier™, who was the developer of the rammed
aggregate pier approach. The proposed Change Order 33 is $214,073.
Results for the building foundation are expected to be functionally equivalent for the two approaches, and the rammed
aggregate pier approach has less risk of groundwater challenges in addition to being the lower cost alternative. The
rammed aggregate pier approach is recommended and is attached as Change Order Proposal #33.
The proposed net increase in the project cost of $218,779 represents a 0.65% increase over the bid cost and would bring
the total change order net increase to 2.64% for the project. A contingency amount of 5.0% was included in the project
budget and financing package. Approval of these change orders would result in a remaining contingency amount of
$800,853.
SUPPORTING DOCUMENTS ATTACHED:
• Change Order Proposal 032 – Rock for Cascade Aeration
• Change Order Proposal 033 – Administration Building Soil Correction
POSSIBLE MOTION
PLEASE WORD MOTION AS YOU WOULD LIKE IT TO APPEAR IN THE MINUTES:
Motion to approve Change Order Proposals as indicated above in the amount of $218,779 to Rice Lake Construction
Group.
BUDGET INFORMATION
FUNDING: BUDGETED:
Fund 602 – Sanitary Sewer Utility
Yes
March 20, 2024
AE2S
6901 East Fish Lake Rd.
Suite 184
Maple Grove, MN 55369-5457
ATTN: Scott Schaefer, PE
Re: Otsego West WWTF Improvements Phase 1
RLCG Project No. 2215
Change Order Proposal #: 032 – Rock for Cascade Aeration
Scott,
During the excavation for the Cascade Aeration, groundwater was discovered. After notifying
AE2S of the water, Rice Lake was directed to install 12” of rock below the base slab and pump
out the water while the base slab was being poured. The total cost to furnish and install the
rock was $4,706.00. Attached is a breakout of the costs.
Please let me know if you have any questions.
Sincerely,
Rice Lake Construction Group
Matt Perpich
Project Manager
2215
Otsego West WWTF Improvements Phasae 1
22360 County Road 12, PO Box 517 3/20/2024
Deerwood, MN 56444 32
HOURS $ RATE TOTAL RATE TOTAL
RLCG Labor 10.00 HR 10.00 99.00$ $990.00 -$ $0.00 -$ -$ 990.00$
RLCG Material -$ $0.00 $0.00 -$ -$ -$
-$ $0.00 $0.00 -$ -$ -$
-$ $0.00 $0.00 -$ -$ -$
Rock 1.00 LS -$ $0.00 $2,200.10 $2,200.10 -$ -$ 2,200.10$
White Cap - Fabric 1.00 LS -$ $0.00 $617.45 $617.45 -$ -$ 617.45$
-$ $0.00 $0.00 -$ -$ -$
-$ $0.00 $0.00 -$ -$ -$
-$ $0.00 $0.00 -$ -$ -$
-$ $0.00 -$ $0.00 -$ -$ -$
Misc. Small Tools and Mat'l 5% of Labor 1.00 ea 5.00%49.50$
Sales Tax 1.00 ea 7.375%207.79$
Totals 10.00 990.00$ 2,817.55$ -$ -$ 4,064.84$
Rice Lake Mark-up on Subs (5%)-$
Rice Lake Mark-up on Labor, Material, and Equipment (15%)571.13$
Bond Cost (1.5%)69.54$
Total Change Order Proposal Request 4,706.00$
Days Requested 0
MATERIAL SUBCONTRACTOR
TOTAL
EQUIPMENT
TOTAL LINE TOTALDESCRIPTIONQTYUNITLABOR
RLCG PROJECT #:
PROJECT NAME:
DATE:
COP:
CHANGE ORDER PROPOSAL
ON ACCOUNT *58083614 *
686 - WC St Paul MN (BW)
2575 Kasota Avenue
St Paul, MN, 55108
(651) 647-0950
RECEIPT
**REPRINT**
58083614
Sold To:153024000
RICE LAKE CONSTRUCTION GROUP
PO BOX 517
DEERWOOD, MN, 56444
218-546-5519
Ship To :OTSEGO WTP,10004328297
7551 LANCASTER AVE NE
OTSEGO, MN, 55301
Job Site Contact: SAM BOELTER
Job Site Phone: 218-866-2871
Map #:
Printed By : Shamini P
Printed Date : 03/08/2024 10:35 AM CENTRAL Ordered By: SAM BOELTER Contact Phone: 218-8662871
Order Number Order Date Request Date Invoice Date Salesperson
58083614 03/08/2024 03/11/2024 Simpson, A
Terms Shipping Method Customer PO Created By
N10THPROX 2. Our Truck 2215-S18459 Shamini P
LN Part#Description Quantity UOM Price Amount
BIN H/M LOT/SN ORD SHP BKO Unit WT COO
** PLEASE
DELIVER MONDAY
3/11/24 **
***************
1.1
1-C4105A
2-C4104A
157R180N15
VPN:
180N/15/300
15' X 300' 500 SY 180N
NON WOVEN
GEOTEXTILE MIRAFI
TENCATE
1 1 0 RL
250 LBS
$575.04 $575.04
Shipped amount $575.04
Order charges $0.00
Tax amount $42.41
Order total $617.45
Deposit/funds tendered $0.00
Balance due $617.45
REPORT DISCREPANCIES WITHIN 24 HRS.
IF YOU DIDN'T RECEIVE THE SERVICE YOU EXPECTED CALL GENE SAMMARTINO 925-595-1778
NO REFUNDS OR EXCHANGES ON NON STOCK MERCHANDISE
PRINT:____________________________________________________________SIGN : ___________________________________________________________
SHIPPED WEIGHT: 250.00 LBS PULLED BY:_______________CHECKED BY: _____________________LOADED BY: _________________
Download any needed Safety Data Sheets (SDS) online today at
https://www.whitecap.com/help-center/osha-standards-safety-data-sheets.
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Scan for Terms and Conditions
March 21, 2024
AE2S
6901 East Fish Lake Rd.
Suite 184
Maple Grove, MN 55369-5457
ATTN: Scott Schaefer, PE
Re: Otsego West WWTF Improvements Phase 1
RLCG Project No. 2215
Change Order Proposal #: 033 – Administration Building Soil Correction
Scott,
During the excavation for the Administration Building, it was discovered that the top 4’-8’ of soil
was unsuitable material and would not be able to support the new building. After discussing
with AE2S, two options were reviewed to determine the most cost-effective solution. The two
options were to perform a complete soil correction or install rammed aggregate piers.
It was found that installing rammed aggregate piers was the cheaper option . Therefore, this
proposal is to install rammed aggregate piers beneath the footings and slabs of the
Administration Building. The total cost to complete this work is $214,073.00. Attached is a
breakout of the costs.
As part of this proposal, it is assumed that Rice Lake will be able to start on the excavation for
the footings of the Administration Building by 5/1/24 as outlined in the project schedule. If that
is not the case, we may need to review the schedule with the project team to determine if
there is a way to adjust the sequencing to avoid a project delay.
Please let me know if you have any questions.
Sincerely,
Rice Lake Construction Group
Matt Perpich
Project Manager
2215
Otsego West WWTF Improvements Phase 1
22360 County Road 12, PO Box 517 3/21/2024
Deerwood, MN 56444 33
HOURS $ RATE TOTAL RATE TOTAL
RLCG Labor 264.00 HR 264.00 99.00$ $26,136.00 -$ $0.00 -$ -$ 26,136.00$
RLCG Material 1.00 LS -$ $0.00 50,166.67$ $50,166.67 -$ -$ 50,166.67$
RLCG Equipment 1.00 LS -$ $0.00 $0.00 -$ 29,700.00$ 29,700.00$
-$ $0.00 $0.00 -$ -$ -$
Ground Improvement Engineering 1.00 LS -$ $0.00 $0.00 80,000.00$ -$ 80,000.00$
-$ $0.00 $0.00 -$ -$ -$
-$ $0.00 $0.00 -$ -$ -$
-$ $0.00 $0.00 -$ -$ -$
-$ $0.00 $0.00 -$ -$ -$
-$ $0.00 -$ $0.00 -$ -$ -$
Misc. Small Tools and Mat'l 5% of Labor 1.00 ea 5.00%1,306.80$
Sales Tax 1.00 ea 7.375%3,699.79$
Totals 264.00 26,136.00$ 50,166.67$ 80,000.00$ 29,700.00$ 191,009.26$
Rice Lake Mark-up on Subs (5%)4,000.00$
Rice Lake Mark-up on Labor, Material, and Equipment (15%)15,900.40$
Bond Cost (1.5%)3,163.64$
Total Change Order Proposal Request 214,073.00$
Days Requested 0
RLCG PROJECT #:
PROJECT NAME:
DATE:
COP:
CHANGE ORDER PROPOSAL
MATERIAL SUBCONTRACTOR
TOTAL
EQUIPMENT
TOTAL LINE TOTALDESCRIPTIONQTYUNITLABOR
Page 1 of 3
March 21, 2024
Matt Perpich
Rice Lake Construction Group
22360 County Road 12
Deerwood, MN
Rammed Aggregate Pier® Soil Improvement Proposal
Otsego West WWTF – Admin Building
7551 Lancaster Ave NE
Otsego, MN
Dear Mr. Perpich,
We are pleased to provide the design/build Geopier ground improvement proposal for the proposed
Otsego West WWTF – Admin Building project in Otsego, MN. This letter relates our project
understanding, a description of the Geopier ground improvement technique, and includes a
proposal from the licensed Geopier installer for Minnesota Peterson Contractors, Inc. (PCI). Note
that the proposal from our installers will follow shortly after today, but the price noted in
this cover letter is the not-to exceed pricing from our installers.
For our base scope, we will improve the poor soils beneath the building foundations and floor
slab. The Geopier process will eliminate the need for over-excavation and replacement. We
will satisfy tolerable settlement criteria and provide a maximum allowable bearing pressure of
3,000 pounds per square foot (psf) (as designed), or up to 5,000 psf (if desired), for use in the
structural foundation design. In preparing this proposal, we have reviewed the design drawings,
specifications, and geotechnical report.
GEOPIER TECHNOLOGY DESCRIPTION
We will use the replacement Geopier (click link for more descriptive information) process, the
original Geopier technology. The Geopier process begins with drilling 24 diameter shafts, placing
fine to coarse aggregates in lifts in the shafts, and then vertically ramming the aggregate lifts with
a specially-designed, beveled tamper.
PROJECT UNDERSTANDING
Based on a review of the structural drawings, we understand the project will consist slab on grade
admin building. Maximum service column and wall loads are understood to be at 8 kips and 7.2
kips per lineal foot, respectively. Maximum slab pressure has been estimated at 125 pounds per
square foot (psf). The finished floor elevation (FFE) is elevation 948.0 feet; up to +3 feet of
grading is needed to reach the FFE. We used the grading and structural information along with
the Braun Intertec Geotechnical Report dated March 18, 2022 to develop our scope.
RAP Ground Improvement Proposal
Otsego West WWTF – Admin Building, Otsego, MN
Page 2 of 3
GEOPIER TECHNOLOGY APPROACH
All topsoil, asphalt/concrete and other surface materials should be stripped and the building pad
graded to a maximum 2.5% slope at the slab subgrade elevation (assumed at elevation 947.0 +/-
feet). It is the responsibility of others to provide a stable working pad for RAP installation.
Fill that is used to raise grades should be placed and compacted under direction of the Geotechnical
Engineer of record (assumed at 95% of modified proctor maximum dry density) and shall contain
a minimum of 15% fines to ensure drilled cavities do not cave in during installations.
Note that due to the soft clay soils and the amount of grade raise fill needed to reach finished
grades, a brief 2 to 3-week delay period for areas to receive 2 or more feet of fill is required
prior to RAP installation. This is to ensure fill induced settlement is largely out of the system
prior to install. This 2 to 3-week time clock starts once the site has reached finished grades and
must be complete prior to RAP install. This should have little to no impact on the schedule as
there are areas to receive less than 2 feet of fill, so this will not delay mobilization.
PCI will extend the RAP elements through the upper unsuitable soils to tag into the native
competent soils below to create a stiff, engineered subgrade. RAP elements will be installed
beneath the building foundations and floor slabs (if desired).
PCI will provide a Quality Control technician who will perform full-time quality control
observation and testing during pier construction which will include Crowd Stabilization testing.
The reinforcing solution will provide an allowable bearing pressure of 3,000 psf (as designed), or
5,000 psf (if desired), for use in foundation design. We will control post-construction settlements
to 1-inch which is a standard structural criterion.
COST ESTIMATE
Based on the above scope of work, PCI has estimated a base bid lump sum cost of about $70,000
to support the building foundations. If the building floor slab is desired to be supported, this can
be done for an add alternate fee of $10,000.
Approximately 40+/- cubic yards of spoils will be generated (neat measure) for the base scope and
an additional 20+/- cubic yards for the add alternate scope due to the Geopier drilled system. The
cost of spoils handling and removal is not included in our scope of work .
Layout of RAP elements is also not included in our scope of work. Please figure one to two
half-days to layout RAP elements in the field for each scope selected.
Items not included in this bid consist of support/settlement control of non-pier supported areas
(e.g. exterior areas, stoops, floor slab (if the add alternates is not selected), etc.), spoils
handling/removal created from RAP installation, RAP element layout, and removal of obstruction
that mat be encountered during RAP installation (such as pre-existing large rubble that cannot be
penetrated by our equipment).
RAP Ground Improvement Proposal
Otsego West WWTF – Admin Building, Otsego, MN
Page 3 of 3
Please contact Ryan Noteboom regarding contract and schedule questions; if this proposal is
accepted then your contract will be with PCI and Ground Improvement Engineering will provide
the Geopier design and engineering services. We would request an AutoCAD file of the
foundation plans to generate the RAP installation drawings.
Thank you for the opportunity to provide this proposal. We look forward to discussing this with
you further.
Sincerely,
Ground Improvement Engineering
Noah J. C. Brown, P.E. Justin D. Warner, P.E.
Regional Engineer - MN Geotechnical Engineer