AECOM (661) 283-2331 tel
5001 E. Commercenter Dr., Suite 100
Bakersfield, CA 93309
May 13, 2025
Fernando Montes, PE
City of Bakersfield
1501 Truxtun Ave
Bakersfield, CA 93301
Subject: Scope of Work, Fee Proposal, and Sc hedule for Sewer Lift Station Rehabilitation at McCutchen Road and Gosford Road
Dear Fernando,
AECOM Technical Services, Inc. (AECOM) is pleased to submit this scope of work, fee proposal, and schedule to the City of Bakersfield (City) to rehabilitate the existing sewer lift station located near the intersection of McCutchen Road and Gosford Road.
GENERAL DESCRIPTION OF WORK
The existing sewer lift station consists of a wet well and dry pit with five (5) floor-mounted submersible sewage pumps. Each pump is 75 hp with an assumed capacity of 5 MGD and is equipped with a VFD. There is a static bar screen at the entrance to the wet well with 3-inch bar spacing. An unlined earth basin adjacent to the lift station functions as emergency overflow storage.
There is also a standalone electrical building.
The lift station currently operates well below its design flow and the VFDs operate the pumps slowly. Because of this the pumps clog with solids, requiring approximately 2,000 hours per year of City staff time to clear and clean. Ragging and frequent cleanings have resulted in wear on valves and pumping equipment. In addition, the static bar screen also clogs with rags and requires regular cleaning by City staff. The existing odor control and ventilation system are not functional. The overhead gantry crane is not operating correctly. And flooding within the dry pit several years ago damaged the electrical system and lighting is not operational.
The City desires to rehabilitate or replace the existing sewer lift station to address these existing issues and increase capacity to accommodate future demand. A Preliminary Design Report (PDR) is proposed as a first step that can be used as the basis for the engineering design scope of work.
The PDR will include the following topics:
1. Sewer Flows
a. Evaluate existing sewer flows from the 2 022 US3 flow monitoring and data from the existing flowmeter.
b. Summarize future sewer flow scenarios from the parallel sewer trunk main design being prepared for the City by Meyer Civil Engineering, Inc. c. Prepare conceptual pump sizing and selection for both the interim condition using existing flow, and the future condition. Phasing will be discussed based on flowrates so the City could program improvements in the future.
2. Structure
a. Hydraulic capacity of the existing wet well will be estimated using Hydraulic Institute standards. Recommendations will be made if a new or larger wet well would be needed to accommodate the future flow condition.
b. Will evaluate the space limitations for future pumping equipment and piping.
EXHIBIT "B"
AECOM
2 c. Discuss installing OSHA safety grates at roof hatches. d. If a new building is needed to accommodate the future flow condition, the conceptual size and layout will be evaluated. This will include a discussion of where to build a new lift station on the existing parcel and how to accommodate existing operation.
3. Bar Screen
a. Will evaluate impacts of removing the existing static bar screen. b. Will coordinate with Duperon, bar screen manufacturer, on requirements to install and operate a mechanical bar screen upstream of the sewer lift station. c. Will coordinate with Sulzer, pump manu facturer, on best practices to reduce ragging and improve operation.
4. Mechanical Equipment
a. Replacement of pumps for both the interim and future conditions. In the interim smaller pumps could be recommended to operate at higher speeds. b. Replacement of plug and check valves.
c. Size piping for future condition.
d. Evaluate existing overhead gantry crane and make recommendations for repair or replacement.
e. Replacement of existing slide gate.
5. Ventilation and Odor Control
a. Replacement of existing blowers and ductwork.
b. Replacement of existing odor control system and blowers.
6. Electrical and Instrumentation
a. Conceptual load schedule for pumps and equipment.
b. Replacement of all lighting within dry pit.
c. Replacement of all electrical conduits, wiring, and sensors. d. Replacement of existing motor control center.
e. Replacement of existing standby gener ator and automatic transfer switch. f. Replacement of instrumentation equipment.
TASK 1 – PRELIMINARY ENGINEERING PHASE
1. Project kickoff meeting and site visit - Du ring the Kickoff Meeting, AECOM will confirm all aspects of the work to be done and will document in the meeting minutes. This meeting minutes will be the basis for the work. A site visit will be held the same day and include AECOM’s electrical, instrumentation, and civil task leads.
AECOM
3 2. AECOM will hold regular conference calls wi th the City to discuss progress and address questions. Our budget includes six (6) conference calls with a duration of not more than 1 hour each.
3. Draft PDR – AECOM will prepar e a PDR that discusses the items of work described previously.
The PDR will include an AACE Class 5 Opinion of Probable Construction Cost for both the interim and future conditions. The following conceptual drawings (10% design) are anticipated:
Interim condition site plan and yard piping
Interim condition roof plan
Interim condition plan for wet well and dry pit
Interim condition sections (5 sheets total)
Future condition site plan and yard piping
Future condition roof plan
Future condition plan for wet well and dry pit
Future condition sectio ns (5 sheets total)
4. Workshop – AECOM will present the results of the draft PDR to City staff. AECOM will prepare meeting minutes that will assist the City in their review. Our budget includes one (1) workshop with a duration of not more than 2 hours. It is assumed only one set of comments will be provided by the City upon their review of the draft PDR and attendance at the workshop.
5. Final PDR – AECOM will revise the draft P DR based on comments provided by the City. No additional comments are anticipated to be provided upon release of the Final PDR document that will include comments addressed during the City’s one (1) review of the draft PDR.
Deliverables:
- Draft Preliminary Design Report
- Final Preliminary Design Report
OPTIONAL – TOPOGRAPHIC SURVEY
The following items are included in the topographic su rvey as an optional task if authorized by the City.
1. Conduct a laser scan of the interior of the pump station dry pit and electrical building. Laser scanning inside the wet well will be conducted from the roof hatch and is limited to line of sight from the hatch and above the water surface.
2. UAS (unmanned aircraft system) photogrammetri c survey of the pump station site, storage pond, and surrounding area as shown in the sketch below.
3. Cross-sections of McCutch en Road at 50-foot intervals using total station within the UAS survey limits.
4. Invert elevations will be obtained at sewer manholes in McCutchen Road.
5. Rights-of-way of McCutchen Road and Gosford Road will be mapped from record information.
AECOM
4 6. The surveyor will coordinate with Meyer Civil E ngineering, Inc. so that this project is on the datum as the parallel sewer project they are designing for the City.
Deliverables:
- PDF of Topographic Survey
- AutoCAD drawing file with surface TIN
ASSUMPTIONS
Preparation of environmental documentation and/or permitting of any kind is not included. Potholing and utility locating is not included.
Geotechnical investigation is not included.
Structural condition assessment is not included.
If the optional topographic survey is not authoriz ed by the City, the conceptual drawings will be based on the record drawings provided by the City. Dimensions will not be independently verified.
SCHEDULE
Task Completion Duration
Draft Preliminary Design Report 5 months after Notice to Proceed Final Preliminary Design Report 2 month after receipt of City comments Optional – Topographic Survey 2 months after Notice to Proceed FEE
Preliminary Engineering Phase (Fixed Fee) $156,080
Optional – Topographic Survey (Fixed Fee) $ 16,170
We appreciate the opportunity to assist the City with this important project.
Yours sincerely,
Daniel Cronquist, PE, PLS Eric Garibay, PE
Project Manager Principal Engineer
Project Budget
Sewer Lift Station Rehabilitation at McCutchen Road and Gosford Road City of Bakersfield Budget
Task Description
Specialty Professional/Discipline
Principal Engineer
Project Engineer III
Project Engineer II
Project Engineer I
CAD Designer
Technician
Total Hours
Labor
Subconsultant
Other Direct Costs
Total
Task 1 - Preliminary Engineering Phase
Kickoff Meeting and Site Visit 8 4 10 4 26 5,860$ - $ 1,000$ 6,860 $ Meetings (Assume 6) 66 8 20 3,840$ - $ - $ 3,840$ Draft Preliminary Design Report - - $ - $ - $ - $ - Sewer Flow Evaluation 12 16 20 48 9,000$ - $ - $ 9,000$ - Structure Space and Capacity Evaluation 4 8 20 32 5,160$ - $ - $ 5,160$ - Bar Screen Evaluation 81 6 24 3,600$ - $ - $ 3,600$ - Mechanical Equipment Evaluation 4 8 12 24 4,680$ - $ - $ 4,680$ - Ventilation and Odor Control Evaluation 4 8 12 2,760$ - $ - $ 2,760$ - Electrical and Instrumentation Evaluation 4 8 16 28 5,340$ - $ - $ 5,340$ - Prepare report text and editing 20 40 16 40 24 140 23,440$ - $ - $ 23,440$ - Opinion of Probable Construction Cost 40 40 80 19,200$ - $ - $ 19,200$ - Conceptual Drawings (Assume 16 sheets) 16 32 64 128 240 34,720$ - $ - $ 34,720$ Workshop 22 4 8 1,440$ - $ 300 $ 1,740 $ Final Preliminary Design Report 25 42 11 40 32 6 156 26,700$ - $ - $ 26,700$ Quality Management and Project Management 12 24 8 44 9,040$ - $ - $ 9,040$ Total 12 149 252 55 216 160 38 882 154,780$ - $ 1,300$ 156,080$ Personnel Hours
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