Date: 6/24/2021 Page 1 of 2
PROJECT DESCRIPTION:
PROJECT NO: NIB 21-012CA, 2018-11 PURCHASE ORDER NO: P21893 CONTRACTOR: Pacific HydroTech Corporation JL NO:
DESCRIPTION OF CHANGES AND/OR EXTRA WORK: Extra work to install, operate and remove a dewatering system at the lift station site.
ITEM U/M QUANTITY UNIT PRICE TOTAL
S-8 LS 1.00 $318,490.00 $318,490.00
TOTAL ESTIMATED PRICE FOR THIS CHANGE ORDER: $318,490.00 JUSTIFICATION:
No time extension was reqested by the contractor for Contract Change Order No. 4.
Item S-8
CCO # Amount % Date Approved
1 $9,359.75 0.18%
2 $130,394.49 2.50%
3 $28,082.74 0.54%
4 $318,490.00 6.12%
Total $486,326.98 9.34% Number of days impacting the schedule. $5,694,422.98
Original Completion Date: 2/8/2022 Revised Completion Date: 6/9/2022 84 Date Started: 01/4/2021
This document shall become an amendment to the Contract and all provisions of the Contract will apply hereto. This Change Order constitutes a complete and final resolution of all claims of the Contract for additional time or additional compensation related to or affected by work that is the subject of this Change Order. Quantities of items other than Lump Sum are not to exceed the amounts indicated.
Original Contract Amount: $5,208,096.00
45 5/5/2021
6/9/2021
6/23/2021
6/24/2021
CITY OF CORONA
The Contractor is hereby directed to make the herein described changes from the plans and specifications and/or perform the following described work not included in the Plans and Specifications for this project.
WRF3 Sewer Lift Station
Department of Water and Power
CONTRACT CHANGE ORDER NO. 4
Construct a sewer lift station
69880572
DESCRIPTION
Install, operate, and remove dewatering system as
necessary to install shoring and construct the lift station structure.
CONTRACT VARIANCE SUMMARY
In May 2017 a geotechnical study was performed to assess the subsurface conditions below the new lift station site.
The geotechnical engineering consultant completed two exploratory borings within the footprint of the proposed lift station site, and hit refusal at a depth of 27.25' below ground surface (BGS) in both borings. Groundwater was not found during exploratory boring excavation activities. Since no groundwater was discovered during the exploratory borings, the contract and bid documents were prepared based on conditions found in the field in May 2017. The geotechnical report, documenting no groundwater was found to a depth of 27 feet BGS at the project site, was included as an appendix to the bid documents and made available to all bidders during the bid advertisement period. The winter of 2021-22 has been unsually dry, so there was no indication that subsurface conditions would be substantially different than conditions found in May 2017. Pacific HydroTech prepared their bid based on the conditions documented in the geotechnical report. During installation of the shoring system groundwater was consistently observed in each beam-hole location (total of 22 beam-holes) at a depth of approximately 21 feet BGS. Portions of the shoring system were designed to be installed to approximately 37 feet BGS. The lift station foundation was designed to be constructed at approximately 27 feet BGS. Groundwater now found at the site has interfered with completion of the shoring installation and will prevent constructing the lower half of the lift station in a dry condition. Pacific HydroTech has engaged Rain-For-Rent, a dewatering system supplier, to prepare a dewatering plan that would be installed and operated during construction of the lift station foundation, floor and walls. The proposed dewatering system includes (4) dewatering wells with submersible pumps and discharge piping. This change order includes all of the work necessary for Pacific HydroTech to successfully install, operate, and remove a dewatering system as necessary for construction of the lift station. The contact change order for $318,490.00 includes all extra work of any nature associated with dewatering the project site as necessary to enable construction of the proposed improvements.
Revised Contract Amount:
Time Working Days
84 0
0 DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C Date: 6/24/2021 Page 2 of 2
AUTHORIZATION BY CITY:
Recommended for approval by:
Date: __________ _________________________________Date: __________ Steve Patterson Gull Nawaz
Consultant Construction Manager Project Manager
Approved by:
Date: __________ _________________________________Date: __________ Vernon R. Weisman, P.E. Savat Khamphou
Acting Public Works Director & City Engineer
Date: __________
Tom Moody
ACCEPTANCE BY CONTRACTOR:
Greg Chehey Project Manager
Accepted by: _______________________________________________ Title: ____________________________ (Please print name and title)
Signature: _______________________________________________ Date: ____________________________ We, the undersigned Contractor, have given careful consideration to the above described changes and/or extra work and hereby agree that said work is the subject of this Change Order. Quantities of items other than Lump Sum are not to exceed the amounts indicated.
_____________________________
_____________________________
_____________________________
DWP General Manager
District Engineer
DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C 6/25/2021
6/25/2021 6/25/2021
6/25/2021 6/25/2021
6/25/2021
PACIFICHYDROTECHCORPORATION
314 E. 3RD ST, PERRIS, CA 92570
(951) 943-8803 FAX (951) 943-1093
June 23, 2021
City of Corona
755 Public Safety Way
Corona, CA 92880
Attn: Vernon Weisman
Reference: WRF-3 Lift Station Project
Project No. 2018-11
Subject: Lump Sum Proposal for Dewatering – Revised (R4R Markup & Sales Tax) PHC is please to offer the following lump sum cost proposal for dewatering to allow for excavation, shoring and construction of the cast in place sewer lift station structure. This plan has considered dewatering of existing groundwater to approximately 32ft below ground level or elevation 773.0 by use of four (4) dewatering wells (three new and one existing) and two (2) sumps for nuisance water within the excavation as needed.
The three (3) new dewatering wells will each be approximately 60ft deep and located near to center of shoring and no closer than 10ft from shoring beams on the north, east and west sides of the structure. Each dewatering well will have 10” casing and gravel like the existing well. Submersible pumps will discharge into common header with flow meter that will terminate in a desilting tank for discharge either into the WRF3 plant at existing “detention basin” or to the adjacent grass field considering that the existing plant may not be able to accept the full flow from dewatering. All submersible pumps (including those for nuisance water) will be either 240v or 110v single phase and this proposal assumes that we have use of temporary power provided by the Owner at no cost to PHC.
Test Well Installation........................................................ $39,440.00 Test Well Development.......................................................$8,790.00 Install Dewatering and Develop Wells........................... $120,420.00 Maintain Dewatering ..................................................... $132,120.00 Remove Dewatering......................................................... $17,720.00 LUMP SUM PRICE ..........................................$318,490.00 The following are the timelines assumed as part of this proposal:
• Assume Change Order Acceptance and Notice to Proceed by June 25, 2021 • Drill Dewatering Wells and setup pumping systems to commence week of June 28th • Develop Dewatering Wells (estimate 2-4 weeks) through Mid to End of July • Potential for excavation and continued shoring to work concurrent with well development. • Estimate Commencement of concrete formwork to base week of August 2nd, or possibly sooner depending on well development.
Note that the schedule for this work is dependent upon well development and lowering of groundwater level which are a function of the subsurface conditions and cannot be predicted with certainty. Therefore, this proposal assumes that we will evaluate the completion schedule again once we have the subgrade dewatered and ready for construction of the lift station base pad to determine if further extension of the contract completion date is justified.
DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C
PACIFICHYDROTECHCORPORATION
314 E. 3RD ST, PERRIS, CA 92570
(951) 943-8803 FAX (951) 943-1093
PHC Groundwater Cost Proposal (Rev. A) - Page 2
June 23, 2021
Notes:
• The Test Well Installation number is based upon the lump sum price for McMahon to drill the test hole as previously quoted. We have confirmed with McMahon that this same price can be used for the three (3) new deeper holes.
• Proposal numbers for Test Well Installation and Test Well Development were broken out to reflect first the effort required to establish the test well (drilling, casing, pumping and piping, etc.) followed by the monitoring, pump change and equipment rental through the end of June. Ongoing rental cost for test well pumping is covered in the “maintain dewatering” lump sum cost.
Additional Conditions:
• Upon completion of dewatering and removal of all pumps and piping, all wells will be removed to 5ft +/- below grade and abandoned in place with PVC casing either removed or filled with rock. • Discharge of groundwater will be onsite by utilizing both the existing WRF3 detention basin and the adjacent grass field. This proposal does not include any groundwater treatment beyond desilting and does not include any disposal beyond the site as indicated herein.
Sincerely,
Greg Chehey
Pacific Hydrotech Corporation
Att: Cost Breakdown (Revised w/5% Markup for Sub Work and Sales Tax on R4R Purchase Items) DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C PHC Job: C2024
WRF3 Lift Station
DEWATERING PROPOSAL
Dewatering Summary
Printed: 6/23/2021
Raw Numbers Rounded for Proposal
Test Well Installation 39,444.19 39,440.00
Test Well Development 8,787.91 8,790.00
Install Dewatering 120,415.34 120,420.00
Maintain Dewatering 132,120.59 132,120.00
Remove Dewatering 17,723.93 17,720.00
318,491.97 318,490.00
Dewatering Proposal Worksheet.xlsx Page 1 of 6
DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C PHC Job: C2024
WRF3 Lift Station
DEWATERING PROPOSAL
Test Well Installation
Printed: 6/23/2021
TOTAL
Invoices
Light Tower Rental 670.84
DV100C Pump Rental 130.00
Services:
Delivery 4/26-4/27 1,233.38
Delivery 5/19-5/21 1,642.40
Est. Services 350.00
Sold Materials:
10" Casings 2,738.47
Gravel 1,721.34
Fees and Taxes:
Environmental Fee 89.54 15% 1%
Taxes 799.81 Markup Bonds
9,375.78 1,406.37 93.76 10,875.90
TOTAL
Install 4/26-4/27 1,928.50 5% 1%
Install 5/19-5/21 4,726.00 Markup Bonds
6,654.50 332.73 66.55 7,053.77
TOTAL 5% 1%
Drill Test Well 15,741.18 Markup Bonds
15,741.18 787.06 157.41 16,685.65
TOTAL
Labor:
Foreman 93.50 16.00 hrs 1,496.00
Laborer 72.75 4.50 hrs 327.38
Equipment:
Job Truck 39.12 16.00 hrs 625.92
Backhoe 46.69 8.00 hrs 373.52
Materials: 15% 1%
Pipe and Fittings 1,340.00 1.00 LS 1,340.00 Markup Bonds 4,162.82 624.42 41.63 4,828.87
35,934.28 39,444.19
39,440.00
Rain for Rent Invoice (PO)
McMahon Drilling
Pacific Hydrotech
Rain for Rent Invoice (Sub)
Dewatering Proposal Worksheet.xlsx Page 2 of 6
DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C PHC Job: C2024
WRF3 Lift Station
DEWATERING PROPOSAL
Test Well Development
Printed: 6/23/2021
TOTAL
Invoices
Rental Mtl per Estimate 945486 (thru 5/24/21) 1,867.06
Rental Mtl per Estimate 957973 (thru 5/24/21) 316.67
2,183.73 15% 1%
7.75% Sales Tax 169.24 Markup Bonds
2,352.97 352.95 23.53 2,729.44
TOTAL 5% 1%
Drill Test Well - Markup Bonds
- - - -
TOTAL
Addl Rain for Rent
Rental 2,400.00 1.00 LS 2,400.00
Labor:
Foreman 93.50 16.00 hrs 1,496.00
Laborer 72.75 4.50 hrs 327.38
Equipment:
Job Truck 39.12 16.00 hrs 625.92 15% 1%
Backhoe 46.69 8.00 hrs 373.52 Markup Bonds
5,222.82 783.42 52.23 6,058.47
9,928.75 8,787.91
8,790.00
Rain for Rent Invoice
McMahon Drilling
Pacific Hydrotech
Dewatering Proposal Worksheet.xlsx Page 3 of 6
DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C PHC Job: C2024
WRF3 Lift Station
DEWATERING PROPOSAL
Install Dewatering
Printed: 6/23/2021
Unit
Cost Units UM TOTAL
Delivery 3,664.20 1.00 LS 3,664.20
Services and Fees 813.00 1.00 LS 813.00
Well Development 1,900.00 1.00 LS 1,900.00
One Time Sale 16,289.95 1.00 LS 16,289.95
22,667.15 15% 1%
7.75% Sales Tax 1,756.70 Markup Bonds
24,423.85 3,663.58 244.24 28,331.67
Unit
Cost Units UM TOTAL 5% 1%
Install Labor 15,916.00 1.00 LS 15,916.00 Markup Bonds
15,916.00 795.80 159.16 16,870.96
TOTAL 5% 1%
Drill Dewatering Wells 15,741.18 3.00 EA 47,223.54 Markup Bonds 47,223.54 2,361.18 472.24 50,056.95
TOTAL
Addl for Electrical
Spider Boxes, Etc. 1,500.00 1.00 LS 1,500.00
Labor:
Foreman 93.50 40.00 hrs 3,740.00
Operator 93.50 40.00 hrs 3,740.00
Laborer 72.75 40.00 hrs 2,910.00
Equipment:
Job Truck 39.12 40.00 hrs 1,564.80
Backhoe 46.69 40.00 hrs 1,867.60
Reach Fork 71.59 40.00 hrs 2,863.60
Materials: 15% 1%
Pipe and Fittings 3,500.00 1.00 LS 3,500.00 Markup Bonds 21,686.00 3,252.90 216.86 25,155.76
133,673.25 120,415.34
120,420.00
Rain for Rent Install (PO)
McMahon Drilling (Install)
Pacific Hydrotech (Install)
Rain for Rent Install (Sub)
Dewatering Proposal Worksheet.xlsx Page 4 of 6
DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C PHC Job: C2024
WRF3 Lift Station
DEWATERING PROPOSAL
Maintain Dewatering
Printed: 6/23/2021
Unit
Cost Units UM TOTAL
Rental Subtotal 10,173.74 5.00 CYCLES 50,868.70
50,868.70 15% 1%
7.75% Sales Tax 3,942.32 Markup Bonds
54,811.02 8,221.65 548.11 63,580.79
Unit
Cost Units UM TOTAL 5% 1%
Weekly Inspections 2,712.00 5.00 CYCLES 13,560.00 Markup Bonds 13,560.00 678.00 135.60 14,373.60
TOTAL 5% 1%
- Markup Bonds
- - - -
TOTAL
Daily Monitoring 7,511.20 5.00 CYCLES 37,556.00 15% 1%
Ongoing Maintenance 1,827.80 5.00 CYCLES 9,139.00 Markup Bonds 46,695.00 7,004.25 466.95 54,166.20
169,877.05 132,120.59
132,120.00
Rain for Rent Maintain (PO)
McMahon Drilling
Pacific Hydrotech (Maintain)
Rain for Rent Maintain (Sub)
Dewatering Proposal Worksheet.xlsx Page 5 of 6
DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C PHC Job: C2024
WRF3 Lift Station
DEWATERING PROPOSAL
Remove Dewatering
Printed: 6/23/2021
Unit
Cost Units UM TOTAL
Pickup 794.60 1.00 LS 794.60
794.60 15% 1%
7.75% Sales Tax 61.58 Markup Bonds
856.18 128.43 8.56 993.17
Unit
Cost Units UM TOTAL 5% 1%
Removal Labor 6,291.00 1.00 LS 6,291.00 Markup Bonds
6,291.00 314.55 62.91 6,668.46
TOTAL 5% 1%
- - - Markup Bonds
- - - -
TOTAL
Addl for Electrical
Demo Electric 1,500.00 1.00 LS 1,500.00
Labor:
Foreman 93.50 16.00 hrs 1,496.00
Operator 93.50 16.00 hrs 1,496.00
Laborer 72.75 16.00 hrs 1,164.00
Equipment:
Job Truck 39.12 16.00 hrs 625.92
Backhoe 46.69 16.00 hrs 747.04
Reach Fork 71.59 16.00 hrs 1,145.44
Materials: 15% 1%
Misc. 500.00 1.00 LS 500.00 Markup Bonds
8,674.40 1,301.16 86.74 10,062.30
16,677.76 17,723.93
17,720.00
Rain for Rent (Remove)
McMahon Drilling (Remove)
Pacific Hydrotech (Remove)
Rain for Rent (Remove)
Dewatering Proposal Worksheet.xlsx Page 6 of 6
DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C DocuSign Envelope ID: 957CEB8C-C048-4B11-82D9-6923653B131C