1300 Clay Street, Suite 1000 | Oakland, California 94612 | www.terraphase.com October 10, 2025
Glenn Dombeck, P.E.
Director of Public Works
City of Hercules
111 Civic Drive
Hercules, California 94704
sent via email to [email protected]
Subject: Proposal for Engineering and Bid Package Development, Refugio Valley Pond, Hercules, California (Revised 10/10/25)
Dear Mr. Dombeck:
Terraphase Engineering Inc. (Terraphase) is pleased to present this proposal for Engineering Design and Construction Bid Package Development for the removal of accumulated sediment in the Refugio Creek pond at Refugio Vally Park (the Site) and associated sediment dewatering and land application at the City of Hercules Corporation Yard in Hercules, California. Terraphase understands the City of Hercules (City) intends for sediment removal to occur in summer/fall 2026. To meet this schedule, the City requires an Engineering Design and Construction Bid Package by January, with bidding in February and construction commencing in July.
Scope of Work
The following scope of services are proposed to encapsulate the requested scope for Engineering Design and Construction Bid Package development. To achieve the City’s expedited schedule, it is anticipated that portions of the proposed tasks may be conducted simultaneously.
Task 1: Design Investigations
Terraphase will complete the following Design Investigations to help resolve important engineering and construction scope questions necessary to complete the Engineering Design. As discussed with the City, investigations to be completed by Terraphase will include:
• Corporation Yard Topographic Survey by a subcontracted licensed Professional Land Surveyor under Terraphase oversight. This survey can also include, if required, additional topographic survey at the Site if existing Site survey data is not sufficient to support detailed engineering design. • Inspection of the catch basin located on the north side of the pond within the assumed equipment staging area (assumes City can remove/replace steel cover) • Retaining Wall Geotechnical Investigation, including soil sample collection with a CA-licensed geotechnical driller and laboratory analyses for geotechnical parameters needed to design a replacement retaining wall under Terraphase oversight.
• Up to 3 informational Site walks for one Terraphase engineer (as needed) October 10, 2025
Glenn Dombeck, P.E.
Proposal for Engineering and Bid Package Development,
Refugio Valley Pond, Hercules, California (Revised
10/10/25)
The proposed budget for this task includes allowances for subcontractor support for implementation of these design investigations. To provide this proposal to the City in alignment with the City Council agenda schedule, these allowances were based Terraphase recent project experience with similar tasks and are not based on actual subcontractor proposals for these tasks. If actual subcontractor costs exceed these allowances, Terraphase will work with the City to refine the subcontractor’s scope of work, implementation schedule, or procure additional funding.
CCTV/inspection of the storm drain bypass piping, if required, will be added to the construction contract scope of work to be implemented by the selected contractor during construction.
Task 2: Permitting and Stakeholder Support
Terraphase will provide the following permitting and stakeholder support activities. • Prepare a project Stormwater Pollution Prevention Plan (SWPPP) under the State Water Resources Control Board’s Construction General Permit (CGP) and submit the Notice of Intent for coverage under the CGP.
• Evaluate City provisions for discharge of leachate to City sewer for inclusion in the 65/100% Design if applicable
• Evaluate City/County Grading Permit conditions for inclusion in the 65/100% Design • Evaluate City Encroachment Permit conditions for inclusion in the 65/100% Design • Provide technical support during two community meetings organized and facilitated by the City.
Terraphase will support the preparation of technical content and materials in advance of each meeting, attend each meeting, and provide post-meeting notes/next steps for technical elements after each meeting.
The services provided under this task assumes the following permit applications will be finalized and submitted by LSA prior to authorization of this proposal and Terraphase technical support for these permit applications are not required:
• U.S. Army Corps of Engineers (USACE) 404 Permit for discharging of dredged materials • Regional Water Quality Control Board (RWQCB) 401 Permit for verification of a Federal permit • California Fish and Wildlife (CDFW) 1602 Permit for lake and streambed alteration
Task 3: 65% Engineering Design
Terraphase will coordinate and/or complete the following components of the 65% Engineering Design for review by the City’s Public Works Department.
• Facilitate Engineering Design in continued coordination with Balance Hydrologics, Inc (Balance). • Develop sheet list and provide consultation/review on 65% Construction Plan Set • Prepare 65% Engineering Specifications based on initial design understanding October 10, 2025
Glenn Dombeck, P.E.
Proposal for Engineering and Bid Package Development,
Refugio Valley Pond, Hercules, California (Revised
10/10/25)
• Prepare 65% Construction Cost Estimate based on professional judgement and approximation • Prepare and maintain Project Schedule through Construction Contractor Procurement • Compile above-mentioned documents into a single submittal for City review.
The 65% Design will be a collaborative effort, with individual components (e.g., plan sheets, specification sections, etc.) prepared by Terraphase, Balance, and others, with Terraphase responsible for organizing and managing the design process.
Task 4: 100% Engineering Design
Terraphase will coordinate and/or complete the following components of the 100% Engineering Design for review by the City’s Public Works Department.
• Review, compile, and prepare responses to comments received from the City and other stakeholders.
• Continued coordination and review of draft 100% Construction Plan Set • Prepare draft 100% Engineering Specifications including contracting requirements of the City • Prepare 100% Construction Cost Estimate containing vendor estimates and approximations • Prepare 100% Project Schedule projecting through the construction phase of work • Compile above-mentioned documents into a single submittal for City review. • Address City comments and provide a final 100% / Issued for Bid design submittal in preparation of Bid Solicitation
The 100% Design will be a collaborative effort, with individual components (e.g., plan sheets, specification sections, etc.) prepared by Terraphase, Balance, and others, with Terraphase responsible for organizing and managing the design process.
Task 5: Construction Bid Support
Terraphase will provide the following services in support of the City-prepared Request for Proposals (RFP).
• Integrate the 100% Design documents into the City’s standard contract book/RFP. • Provide technical support during City preparation of the construction RFP. • Attendance of one pre-bid conference, recording of live questions, follow-up meeting with the City, and preparation of post-conference notes/minutes.
• Review, compile, and assist providing responses to questions received from the bidders • Support preparation of technical documents (e.g., revised drawings and/or specifications) for one RFP addendum in response to bidder questions, including coordination with Balance and others.
Services proposed for Construction Bid Support assume the City will lead the effort for solicitation of proposals and correspondence with the responding contractors.
October 10, 2025
Glenn Dombeck, P.E.
Proposal for Engineering and Bid Package Development,
Refugio Valley Pond, Hercules, California (Revised
10/10/25)
Task 6: Project Management
Terraphase will assist the City with project management coordinating the above scope of work with project stakeholders.
• Development of a Project Quality Management Plan (PQMP) • Facilitation of recurring project team meetings including the distribution of a meeting agenda and recording of meeting minutes.
• Contract management and coordination with the City
Cost Estimate
Terraphase proposes to complete the scope of work outline and preliminary schedule under contract with the City on a time-and-materials basis, not to exceed $206,879. A detailed cost breakdown is provided in the attached Table 1.
Closing
Terraphase is grateful for the opportunity to offer our services to the City. If you have any questions or comments regarding this submittal, please contact Chris Jones at (860) 989-8538 or [email protected].
Sincerely,
for Terraphase Engineering Inc.
Shakeel Jogia, PE (CA), PMP, CCM Chris Jones, PE (CA)
Principal Engineer Senior Associate Engineer
Attachment: Table 1: Detailed Cost Breakdown
Table 1 - Time and Materials Cost Estimate (Rev 1)
City of Hercules
Proposal for Engineering, Permitting Support, and Bid Package Development Qty Cost Qty Cost Qty Cost Qty Cost Qty Cost Qty Cost Qty Cost Senior Principal Hour 320.00$ 0% 320.00$ 4 1,280$ -$ 6 1,920$ 4 1,280$ -$ -$ 14 4,480$ Principal Hour 301.00$ 0% 301.00$ 14 4,214$ 23 6,923$ 40 12,040$ 24 7,224$ 18 5,418$ 14 4,214$ 133 40,033$ Senior Associate Hour 282.00$ 0% 282.00$ 23 6,486$ 28 7,896$ 42 11,844$ 37 10,434$ 13 3,666$ 34 9,588$ 177 49,914$ Associate Hour 264.00$ 0% 264.00$ 6 1,584$ 8 2,112$ 46 12,144$ 25.5 6,732$ 9 2,376$ 8 2,112$ 102.5 27,060$ Senior Project Hour 247.00$ 0% 247.00$ -$ -$ -$ -$ -$ -$ 0 -$ Project Hour 230.00$ 0% 230.00$ -$ -$ -$ -$ -$ -$ 0 -$ Senior Staff 2 Hour 213.00$ 0% 213.00$ 58 12,354$ 48 10,224$ 42 8,946$ 57 12,141$ 12 2,556$ 1 213$ 218 46,434$ Senior Staff 1 Hour 193.00$ 0% 193.00$ -$ -$ -$ -$ -$ -$ 0 -$ Staff 2 Hour 171.00$ 0% 171.00$ -$ -$ 70 11,970$ 57 9,747$ -$ 1 171$ 128 21,888$ Staff 1 Hour 149.00$ 0% 149.00$ -$ -$ -$ -$ -$ -$ 0 -$ Senior Technician Hour 156.00$ 0% 156.00$ -$ -$ -$ -$ -$ -$ 0 -$ Technician 3 Hour 136.00$ 0% 136.00$ -$ -$ -$ -$ -$ -$ 0 -$ Technician 2 Hour 114.00$ 0% 114.00$ -$ -$ -$ -$ -$ -$ 0 -$ Technician 1 Hour 96.00$ 0% 96.00$ -$ -$ -$ -$ -$ -$ 0 -$ Senior Editor/ Senior Project Coordinator Hour 166.00$ 0% 166.00$ -$ -$ -$ -$ -$ -$ 0 -$ Editor 2/Project Coordinator 2/Accountant 2 Hour 147.00$ 0% 147.00$ -$ -$ -$ -$ -$ -$ 0 -$ Editor 1/Project Coordinator 1/Accountant 1 Hour 122.00$ 0% 122.00$ -$ -$ -$ -$ -$ -$ 0 -$ Administrator/Project Assistant/Billing Specialist Hour 103.00$ 0% 103.00$ -$ -$ -$ -$ -$ 13 1,339$ 13 1,339$ 25,918$ 27,155$ 58,864$ 47,558$ 14,016$ 17,637$ 191,148$ Geotechnical Laboratory Allowance 1,000.00$ 1,000.00$ 1 1,000$ -$ -$ -$ -$ -$ 1 1,000$ Topographic Survey (Mountain Pacific) Allowance 7,000.00$ 7,000.00$ 1 7,000$ -$ -$ -$ -$ -$ 1 7,000$ Utility Locating (GPRS) Allowance 750.00$ 750.00$ 1 750$ -$ -$ -$ -$ -$ 1 750$ Geotechnical Driller Allowance 4,000.00$ 4,000.00$ 1 4,000$ -$ -$ -$ -$ -$ 1 4,000$ 12,750$ -$ -$ -$ -$ -$ 12,750$ Drilling Permit Allowance 445.00$ 445.00$ 1 445$ -$ -$ -$ -$ -$ 1 445$ 445$ -$ -$ -$ -$ -$ 445$ Direct Cost Handling 10% 10.0% 1,320$ -$ -$ -$ -$ -$ 1,320$ Total Direct Costs 14,515$ -$ -$ -$ -$ -$ 14,515$ Truck/Vehicle (day) Day 206.00$ 206.00$ 4 824$ -$ -$ -$ -$ -$ 4 824$ IPad and Electronic Field Data (day) Day 40.00$ 40.00$ 4 160$ -$ -$ -$ -$ -$ 4 160$ Daily Consumables (includes gloves, ziplock bags
and trash bags) Each 24.00$ 24.00$ 4 96$ -$ -$ -$ -$ -$ 4 96$ Field Health and Safety and Decon Supplies (daily
fee) Day 34.00$ 34.00$ 4 136$ -$ -$ -$ -$ -$ 4 136$ Total Terraphase Equipment/Supplies (ERS) 1,216$ -$ -$ -$ -$ -$ 1,216$ Mileage mile 0.700$ 0.700$ -$ -$ -$ -$ -$ -$ 0 -$ Total Mileage Costs -$ -$ -$ -$ -$ -$ -$ 41,649$ 27,155$ 58,864$ 47,558$ 14,016$ 17,637$ 206,879$ Task 2:
Permitting and
Stakeholder Support
Task 3:
60% Design Total
Task 1:
Design
Investigations
Task 4:
100% / IFB Design
Task 5:
Bid Support
Task 6:
Project
Management
Total Subcontractor Costs
Total Terraphase Labor
Total Other Direct Costs
Total Estimated Project Unit Costs
Category Units Standard
2025 Rate Discount Rate
Mileage Costs
Labor
Direct Costs
Subcontractor
Other Direct Costs
Terraphase Equipment/Supplies (ERS)
+
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