HomeMy WebLinkAbout2023-036 A1 Carollo Engineers C2023W01Page 1 of 1
AMENDMENT TO CONTRACT No. 1
PO #02612
Carollo Engineers, Inc.
for
Professional Services
Wastewater Master Plan Update Project
C2023W01
THIS AMENDMENT TO THE CONTRACT is made and entered into by and between the CITY
of ATASCADERO, a Municipal Corporation (“City”), and Carollo Engineers, Inc. (“Consultant”)
All certifications and assurances as agreed to in the specifications and contract dated October
25, 2023 are hereby incorporated into this amendment. The following scope of work and
compensation are in addition to that specified in the aforementioned contract:
REGARDING CONTRACT ITEM 3 – TIME OF PERFORMANCE: Contract termination date
shall be extended until December 31, 2026.
REGARDING EXHIBIT A – SCOPE OF WORK: Exhibit A is hereby amended to include the
additional work for Tasks 1-8 as described in the “Collection System Flow Monitoring, Hydraulic
Model Update, and Infiltration/Inflow Amendment” proposal, dated September 25, 2025, (Exhibit
A-1), and generally described as:
1. Wastewater collection system flow monitoring, hydraulic model update, system
evaluation and updated CIP, infiltration/inflow study, and preparation of a summary
technical memorandum.
REGARDING ITEM EXHIBIT B - COMPENSATION AND METHOD OF PAYMENT: Exhibit B is
hereby amended to include the costs for additional work described above, at the request of the
City. Total additional compensation will be equal to the cumulative hours of each employee
class times standard hourly rates, not to exceed the net contract increase of $239,700 for a total
revised contract price of $425,100.
All other terms of the original Contract remain in effect.
Dated: October 15, 2025
Carollo Engineers
By:_____________________________
Ryan Orgill, Associate Vice President
City of Atascadero
By:_____________________________ By:_____________________________
Nicholas DeBar, Public Works Director City Manager/Designee
Docusign Envelope ID: C238B390-6A4D-45EF-95CD-D2D5AB149303
EXHIBIT A-1
Scope of Work
Docusign Envelope ID: C238B390-6A4D-45EF-95CD-D2D5AB149303
1401 Fulton Street, Suite 802
Fresno, California 93721
P 559-436-6616
carollo.com
401.86 / Flow Monitoring and Model Update Scope
September 25, 2025
Ryan Hayes, P.E.
City of Atascadero
6500 Palma Avenue
Atascadero, CA 93422
Subject: Collection System Flow Monitoring, Hydraulic Model Update, and Infiltration/Inflow (I/) Amendment
Dear Mr. Hayes:
In accordance with your request, Carollo Engineers, Inc., (Carollo) is pleased to provide the City of Atascadero
(City) with the following scope and fee estimate to conduct temporary flow monitoring and update the City’s
wastewater collection system hydraulic model.
Background
Carollo is currently working with the City to complete the Collection System Master Plan Update (Master Plan
Update). The Master Plan Update will provide the City with recommended improvements to mitigate existing
capacity constraints and to serve future customers. However, additional flow monitoring data is needed to
confirm flows and levels within specific areas within the City. The flow monitoring data will be used to confirm the
sizing of recommended improvements and potentially identify additional improvements. The flow monitoring
data will establish the amount of inflow and infiltration (I/I) entering the collection system.
Our preliminary scope of work is provided below.
Scope of Work
Task 1: Project Management and Meetings
Carollo will prepare for and attend one project kick-off meeting and up to three workshops to present findings.
Carollo will also continue bi-weekly check-ins with the City. Carollo will prepare and distribute brief meeting
minutes summarizing meeting discussion, decisions, and action items. Carollo will also perform project
management tasks, including coordinating with City, monitoring project schedule and budget, and preparing and
delivering monthly invoicing with status updates. This task also includes QA/QC. Carollo’s technical advisor will
conduct a thorough review of all project deliverables as part of this task.
Task 1 Deliverables:
▪ Meeting agendas and action items.
▪ Monthly invoices and progress reports.
Task 2: Phase I Flow Monitoring
Carollo and it’s subcontractor Krajewski Flow Monitoring Solutions (K-Flow) will collect flow and rainfall data for
representative areas within the City’s wastewater collection system. The temporary flow monitoring program will
consist of 13 gravity flow meters and one lift station logger, to be installed for a duration of four weeks. Extension
beyond this timeframe can be provided as an additional service. The flow meters will be installed during a time
Docusign Envelope ID: C238B390-6A4D-45EF-95CD-D2D5AB149303
Ryan Hayes, P.E.
City of Atascadero
September 25, 2025
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period deemed to be the most conducive for capturing flows during significant wet weather periods. After the
flowmeters are removed, the raw data will be reviewed for quality control (QAQC) and reduced to 15-minute
intervals and provided in electronic format. An analysis of the flow monitoring data will be conducted and will
include the following:
▪ Baseline flows, levels, and velocities
▪ Isolation and quantification of I/I flows per site and per monitoring basin.
▪ Identification of inflow and infiltration metrics.
▪ Normalized ranking of flow monitoring basins for each inflow and infiltration parameter.
Rainfall data will also be collected to determine the storm event classifications for any major rainfall event
captured during the flow monitoring program.
All work completed as part of Task 2 will be documented in a draft and final Flow Monitoring and I/I Analysis
Study report. Carollo will perform QA/QC on the data and draft report provided by K-Flow and provide
comments to be incorporated in the final deliverables.
Task 2 Deliverables:
▪ Flow Monitoring Data (excel spreadsheet).
▪ Draft and Final Flow Monitoring and I/I Analysis Study report.
Task 3: Updated Land Use Analysis and Flow Projections
As part of this task, Carollo will also provide an updated existing land use analysis, where updated baseline
wastewater flows per acre for each major existing land use category. The updated land use flow factors will be
compared to the ones presented in the Master Plan Update and the flow projections will be updated if necessary.
This will not include an updated population analysis. The updated land use analysis may be used to update the
existing calibrated loads and/or future flows in the model.
Task 4: Hydraulic Model Calibration Update
Based on the flow monitoring data collected as part of Task 2, Carollo will re-calibrate the City’s existing hydraulic
model. The calibration will include dry weather and wet weather flow calibration at each of the flow monitoring
sites as well as available SCADA data at the City’s lift stations and WWTP. Carollo will provide a data request list
to the City following the completion of the flow monitoring program. Separate calibrated dry weather loads and
wet weather parameters will be developed for each flow monitoring basins in the model.
Carollo will review the updated land use analysis and calibration results with the City at a workshop.
Task 4 Deliverables:
▪ Updated hydraulic model files.
Task 5: System Evaluation and Updated CIP
Based on the updated calibrated model, Carollo will re-evaluate the existing and future scenarios to confirm the
need and sizing of the previously recommended improvements and determine if any additional improvements
Docusign Envelope ID: C238B390-6A4D-45EF-95CD-D2D5AB149303
Ryan Hayes, P.E.
City of Atascadero
September 25, 2025
Page 3
are needed. Carollo will hold a workshop with City staff to review the updated system evaluation. Feedback
provided by the City will be incorporated into the final system improvements. Based on the updated existing and
future system evaluation, Carollo will update the capital improvement project (CIP) costs, tables, maps, and
project detail sheets that were developed as part of the Master Plan effort. The updated CIP will be included in
the technical memorandum (Task 5).
Task 6: Infiltration/Inflow Study
The Carollo/K-Flow Team will evaluate the flow monitoring data, as well as other relevant information collected
during the study to quantify I/I in each sub-area and to identify the sub-areas with excessive I/I. A summary of
the findings, and options for follow up I/I investigations and/or corrective measures such as cross
connection/illicit connection removal, point repairs, Cure in Place Pipe (CIPP) lining, and manhole waterproofing
will be presented. The study will include a prioritized list of corrective measures with definition of each
recommended specific measure and budget level cost estimates.
Task 7: Technical Memorandum
All work completed under Tasks 2 through 6, as well as Optional tasks 8-10 (if included in the final scope) will be
summarized in a draft technical memorandum (TM). A final TM will be submitted to the City two weeks after
receiving all comments. The draft and final TM will be submitted in electronic format (no hard copies).
Task 7 Deliverables:
▪ Draft and Final Technical Memorandum.
Task 8: Phase II Flow Monitoring (Optional Task)
The Phase I flow monitoring data will be analyzed mid-study and presented to the Carollo/City team to
determine if it is viable and worthwhile to extend the project by one month and relocate the flow meters into
sub-basins to further isolate and identify sources of I/I. Data collected from Phase II would be integrated into the
flow monitoring and I/I report. Phase II meter relocation will require authorization by Carollo and the City.
Task 8 Deliverables:
▪ Task 8 deliverables to be grouped with Task 2 deliverables
Task 9: Nighttime I/I Reconnaissance (Optional Task)
K-Flow will investigate the manhole structures, sewer alignments, and other related sewer basin components,
looking for evidence of infiltration and inflow. Work will likely be conducted during the low-flow hours of
between 1:00 am and 4:30 am, when I/I flow is most evident (“clear-water” flow). Evidence of I/I that may be
revealed during the investigations includes, but is not limited to, the following items: structural defects within
manholes, visible tracking of I/I flow during a storm event, suspicious storm crossings, and direct connections
from roof leaders into sanitary sewer clean-outs.
Limitations to this work include the following: (1) the source of I/I may not be traceable from this work; and (2)
this work may be dependent on investigations taking place during storm events, which are unpredictable.
Evidence of I/I will be documented and, whenever possible, evidence of I/I will be quantified. Depending on the
Docusign Envelope ID: C238B390-6A4D-45EF-95CD-D2D5AB149303
Ryan Hayes, P.E.
City of Atascadero
September 25, 2025
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characteristics and conditions unique to the basin(s) being investigated, investigative measures implemented may
include general and/or detail reconnaissance, and/or basin isolation. This task assumes approximately two
sessions would be utilized for this work. I/I reconnaissance would likely take place after the Phase II flow
monitoring and later in the wet weather season, estimated for February, March or April 2026.
Depending on the timing of the field work in respect to the timing of the other deliverables required for the flow
monitoring project, the data and information obtained will either be (a) compiled and merged with the data and
work already completed in earlier phases of this project as part of an all-inclusive final report, or (b) submitted as
a separate final report.
The deliverable will include a narrative about the methods used, and will include photographs, maps, graphs and
tables, as necessary, to document and illustrate the results of the investigations.
Task 9 Deliverables:
▪ I/I reconnaissance findings in stand alone report, or grouped with Task 2 deliverables
Task 10: Smoke Testing (Optional Task)
This optional task includes the following:
▪ Preparation: K-Flow will gather, and review documents and information provided by including maps of the
study area and a list of streets and addresses within the study area. K-Flow will use this information to plan
the testing locations and associated smoke testing fieldwork. K-Flow will be responsible for the distribution of
the 1st round of notifications at least 2 weeks ahead of time. K-Flow will also distribute a 2nd round
notifications to the affected residents and businesses no more than 48 hours before the commencement of
smoke testing.
▪ Field Work: K-Flow will perform smoke testing of the sanitary sewer lines as directed by Carollo and the City.
K-Flow will attempt to minimize impacts or inconveniences to the community, but at the same time maintain a
high level of reporting accuracy. Work hours will be between 8:00 AM and 5:00 PM on low-traffic volume
streets and between 9:00 AM and 3:30 PM on arterial streets. K-Flow will not perform smoke testing on
private properties or easements without assistance from the City. K-Flow will not perform smoke testing in the
proximity of schools during morning drop-off and afternoon pick-up hours. Smoke testing will not be
performed on weekends or holidays unless required by special circumstance. K-Flow will be responsible for
the execution and equipment for this project.
It is estimated that between 6,000 and 10,000 lineal feet can be completed in one day of smoke testing. The
base cost for this task assumes two full days of smoke testing, inclusive of all notification and reporting costs.
If pre-planned appropriately to occur during the same period as the base smoke testing, additional days of
smoke testing can be added. Smoke testing is best conducted during dry weather and during dry soil
conditions. It is estimated this work would take place between June and September, 2026.
▪ Report: K-Flow will provide documentation of system deficiencies and illicit connections that could be sources
of inflow or infiltration found during smoke testing. K-Flow will summarize findings in a final report, including
the identification of parcels, photographic documentation, and GPS coordinates.
Docusign Envelope ID: C238B390-6A4D-45EF-95CD-D2D5AB149303
Ryan Hayes, P.E.
City of Atascadero
September 25, 2025
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Task 10 Deliverables:
▪ Smoke testing findings
We appreciate the opportunity to submit this proposal and are excited for the chance to continue working with
your team. If you have questions, feel free to reach out to me at 559-284-5451.
Sincerely,
CAROLLO ENGINEERS, INC.
Ryan Orgill, P.E.
Associate Vice President
RFO:ro
Enclosures: Fee Estimate
Docusign Envelope ID: C238B390-6A4D-45EF-95CD-D2D5AB149303