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October 13, 2026

ADDENDUM NO. 1

TO THE CONTRACT DOCUMENTS

Long Beach Public Utilities Department Long Beach, California Specifications No. WD-06-26 Drawing No. SC-0512

CHERRY AVENUE SEWER IMPROVEMENT PROJECT

TO ALL PLAN HOLDERS

The following amendments are hereby made a part of the Contract Documents of the subject project as fully and completely as if the same were set forth therein. This Addendum No. 1 consists of pages AD1-1 to AD1-50, including attachments.

The Bid opening date and time stated in the Notice Inviting Bids, Page 1 of 6, has been extended to: 2:00 PM, Friday, October 16, 2026.

BID EXTENSION

Item No.: 1.01 Location: Notice Inviting Bids, Page 1 of 6 – Bid Opening Date Action: Revision

The bid opening date stated in the Notice Inviting Bids is hereby revised as follows:

• DELETE: 2:00 PM, October 14, 2026

• REPLACE WITH: 2:00 PM, Friday, October 16, 2026

All other terms and conditions of the Notice Inviting Bids remain unchanged.

ANTICIPATED PLAN REVISIONS

Plan review comments have been received from the Los Angeles County Flood Control District

(LACFCD) and the Los Angeles County Sanitation Districts (LACSD). The Drawings will not be revised prior to the opening of Bids. The Drawings will be revised and conformed to include the items below prior to execution of the Contract. The items are provided so that Bidders are aware of them in preparing their Bids.

Item No.: 1.02

Location: Drawings, All Sheets – LACFCD Facilities

Action: Anticipated Revision

The Drawings will be revised to address the following LACFCD comments:

a. Existing LACFCD catch basin(s) will be labeled “Existing LACFCD CB,” and existing

LACFCD laterals will be labeled “Existing LACFCD 18-inch lateral” (or other size, as applicable).

1800 E. Wardlow Road Long Beach, CA 90807

562.570.2300 │LBUtilities.org

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b. The LACFCD storm drain manhole at the intersection of Cherry Ave. and 10th St. will be shown and called out, with stationing and tick marks, on both the plan and cross section views.

c. All plan sheets will be labeled: “Not to be maintained by LACFCD, to be maintained by Long Beach Public Utilities Department.”

Item No.: 1.03

Location: Drawings, Sheet 4 and All Sheets – LACSD Facilities

Action: Anticipated Revision and Addition

Sheet 4 will be revised to update the LACSD agency contact information. The following LACSD requirements apply to the Work:

1. Provide a minimum 3-foot horizontal clearance to LACSD sewers, including all excavation and shoring.

2. Maintain adequate manhole access (typically 15 feet wide) to existing LACSD manholes within the project area at all times, during construction and after completion of the project, so that LACSD can reach the manholes for routine operation, maintenance, and emergency response.

3. Protect existing LACSD manholes in place during construction. Adjustments to

LACSD manholes shall be performed in accordance with LACSD’s requirements per

“Adjustment of Los Angeles County Sanitation Districts Manholes to New Grade”

(LACSD DOC 301411, Rev. 10/2024).

4. Compaction by vibrating, jetting, or other mechanical means is not allowed where the proposed work is within two feet above the existing LACSD sewer. Jetting is prohibited throughout the project per General Note 23 on the Plans.

5. Notify LACSD’s Superintendent of Wastewater Collection Systems (O&M) at (310)

638-1161 a minimum of five (5) working days prior to the start of any work involving

LACSD manholes.

REFERENCE INFORMATION

Item No.: 1.04

Location: Addendum AD1-5 - LACSD Adjustment of Los Angeles County Sanitation Districts Manholes to New Grade (DOC 301411)

Action: Addition

The LACSD handout, Adjustment of Los Angeles County Sanitation Districts Manholes to New Grade (DOC 301411, Rev. 10/2024), is attached as AD1-5.

Item No.: 1.05

Location: Addendum AD1-6 to AD1-50 - Sewer Flow Monitoring Report dated December 19, 2025

Action: Addition

The Sewer Flow Monitoring Report (PCAP Flow Monitoring Projects 4 and 5, Long Beach 2025, prepared by ADS Environmental Services for GHD, dated December 19, 2025) is attached as AD1-6 through AD1-50. In accordance with General Conditions Section 4.2.2, the Contractor may rely on the accuracy of the technical data contained in reports; however, AD1-3 non-technical data, interpretations, and opinions contained in reports shall not be relied on by the Contractor.

BIDDER QUESTIONS

1. Question: Will LBUD provide videos or photos showing the current condition of the maintenance holes to be modified under Bid Item No. 15?

Answer: Photos of select maintenance holes are provided in Sewer Flow Monitoring Report

Item 1.05. The report includes site report forms with photographs and the recorded depth, material, and condition of each monitored maintenance hole. No video of maintenance hole conditions is available.

The following questions relate to Section 33 01 38 – Maintenance Hole and Wet Well

Rehabilitation:

2. Question: Part 1.6 B requests a Flow Control Plan for bypassing sewage around each maintenance hole to be rehabilitated. Do existing conditions require the use of above-ground flow bypass for MH rehabilitation, or will LBUD accept a plan using flow-through bypass equipment?

Answer: Existing sewers will be carrying flow during the Work (Section 33 01 30, Part 1.1.F), and flow control is the Contractor’s responsibility (Section 33 01 38, Part 3.1.D). LBUD will review a Flow Control Plan that uses flow-through bypass equipment. The plan shall maintain uninterrupted sewer flow, prevent sewage spills, and comply with Section 33 01 30.

3. Question: Part 3.1 G.4 discusses the use of concrete repair mortar on the channel and shelf areas. Will LBUD allow this type of trowel-applied structural concrete repair mortar on all interior surfaces as opposed to air-placed gunite?

Answer: Air-placed gunite per Part 3.1 G.2 is required for restoration of interior wall surfaces.

Trowel-applied repair mortar will not be accepted as a substitute for gunite. Repair mortar remains required for channel and shelf areas (Part 3.1 G.4) and for surface repairs (Part 3.1

G.3).

4. Question: Parts 3.1 G.2 and 3.1 G.4 discuss the necessary curing time for gunite (1 day) and repair mortar (7 days) prior to lining application. Will LBUD change the specification so that cure time prior to liner application is based on the manufacturer’s recommendation?

Answer: Cure times remain as specified. LBUD may approve a revised cure time where the

Contractor submits the repair mortar and lining manufacturer’s written recommendations for review and approval by the Owner’s Representative, and the revised time meets the manufacturer’s specifications and warranty requirements.

5. Question: Part 3.1 Installation D.4 lists two termination points for the protective lining, 1” below the water level and at the flow line. Please clarify where to terminate the lining.

Answer: Polyurethane liner or epoxy liner shall be installed from 1” below water level to base of ring and cover and shall not coat the channel. Lining termination shall be keyed. This supersedes “terminate lining at flow line” on D.4.c and E.2.c on page 5 of 8 of 33 01 38.

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A signed copy of the Addenda Acknowledgment form provided in the Bid and a copy of this Addendum No. 1 must accompany the Bid Submittal.

Questions regarding the project shall be directed to Matthew Cruz at (562) 570-2332.

Sincerely, Robert J. Verceles, P.E.

Director of Water/Sewer Engineering cc: Matthew Cruz – Civil Engineer, LBUD

Carolina Avendano – Capital Projects Coordinator IV, LBUD Saik-Choon Poh – DRP Engineering, Inc.

wadepew Image

DOC 301411 Rev. 10/2024

Non-LACDPW regrading and/or resurfacing projects in the LA Basin that require adjustment of LACSD manholes in public rights-of-way shall include the following in their project specifications, or, if already in progress, the Contractor shall follow the following procedures:

ADJUSTMENT OF LOS ANGELES COUNTY SANITATION DISTRICTS MANHOLES TO NEW GRADE

When Los Angeles County Sanitation Districts (LACSD) manholes must be adjusted to new grade because of regrading and/or resurfacing over the manholes, the work shall be done by the Contractor responsible for the re-grading and/or resurfacing work in conjunction with LACSD pursuant to the following procedures:

1. The Contractor shall notify LACSD’s Superintendent of Maintenance at (310) 638-1161 a minimum of five (5) working days prior to the start of any work involving LACSD manholes.

2. The Contractor shall exercise necessary caution to prevent debris from falling into manholes. In the event that debris should fall into the manhole, the Contractor shall notify LACSD and then remove the debris following all required safety measures.

3. If grade over manhole is to be lowered:

a. The Contractor shall furnish and deliver a temporary steel cover plate of adequate thickness and size approved by LACSD for the manhole.

b. The Contractor shall excavate around the manhole to a depth and distance outside of the manhole as required by LACSD.

c. The Contractor shall remove the manhole frame and cover and the interfering portion of the manhole shaft and place the cover plate over the manhole.

d. The Contractor shall store and protect the frame and cover and fill and/or pave over the cover plate to final grade.

e. The Contractor shall remove the pavement and/or fill as required to raise the manhole to final grade.

Pavement and/or fill shall be removed to a minimum depth of not less than 6 inches below final grade and 12 inches around the manhole if the cover plate is more than 6 inches below final grade.

f. The Contractor shall raise the manhole and set the frame and cover to final grade as required by LACSD.

g. The Contractor shall provide a 12-inch wide by 12-inch-high concrete ring around the manhole frame. In unpaved areas, the concrete ring shall include #3 rebar, 12-inch overlap. The Contractor shall backfill and compact and complete the pavement around the manhole.

4. If grade over manhole is to be raised:

a. The Contractor shall fill and/or pave directly over the manhole frame and cover to final grade.

b. Repeat steps e. through g. of Item 2 above except when grade is to be raised more than 2 feet. In such case, the Contractor shall excavate around the manhole to a depth and distance as determined by and required by LACSD. The Contractor shall then remove and reconstruct the manhole shaft with the required taper per LACSD’s standards. All costs associated with the reconstruction of the manhole shafts shall be borne by the Contractor.

The Contractor shall be responsible for furnishing, placing, and maintaining barricades and lights as necessary to protect the public from danger due to the work being performed.

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320 Goddard Way, Suite 200 Irvine, California 92618 United States ghd.com

The Power of Commitment

GHD

Our ref: 12663200

December 19, 2025

Leela Stevens, PE Long Beach Utilities Department 1800 E. Wardlow Road Long Beach, CA 90807

Project Sites 4 & 5 Flow Monitoring Data Results

Dear Ms. Stevens, This first batch of data is for the flow monitoring equipment that was installed by GHD’s subconsultant, ADS

Environmental Service, at Project Sites 4 and 5. As noted through email communication and the December invoice, the following modifications were made:

1. Project Site 4: 4 of 6 sites were installed. 2 sites were not installed due to field conditions. Crew attempted a second date install but conditions remain unchanged. These 2 sites were abandoned and will not be charged.

2. Project Site 5: 2 of 2 sites were installed.

Please let me know if you have any questions regarding the output data presented in the attached documents.

Regards

Pedro Alvarez, PE Project Manager

+1 949 585-5262 pedro.alvarez@ghd.com

Page

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15201 Springdale St. Huntington Beach, CA 92649

800-633-7246 www.adsenv.com

LongBch.GHD.TFM.CA25

PCAP Flow Monitoring Project 4 Long Beach 2025

Final Report Submitted to GHD December 19, 2025

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Thursday, 13 November 2025 to Wednesday, 03 December 2025

Pedro Alvarez Project Manager GHD Proudly employee-owned | ghd.com 320 Goddard Way Suite 200 Irvine CA 92618 USA D 1 949 585 5262 | E Pedro.alvarez@ghd.com

SUBJECT: PCAP Flow Monitoring Project 4 - Long Beach 2025

Dear Mr. Alvarez, ADS is pleased to submit the report for the project referenced above completed on behalf of GHD. The metering was conducted at four (4) location(s). This Project 4 was originally intended for six (6) locations, but 2 were eliminated due to field conditions and approved by GHD. The study was conducted during the period of Thursday, 13 November 2025 to Wednesday, 03 December 2025.

The report contains depth, velocity, and quantity hydrographs as well as daily long tables for the metering period. An Excel file containing depth, quantity, and velocity entities for the monitoring location in 5-minute format was provided previously.

In addition, we would be happy to further explain any details about the report that may seem unclear. Should you have any questions or comments, you may contact the Project Manager, Paul Mitchell at (714)-920-4418.

It has been our pleasure to be of service to you in the performance of this project. Thank you for choosing ADS products and services to meet your flow monitoring needs.

Sincerely, ADS ENVIRONMENTAL SERVICES

Justin Hatch Data Analyst

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PCAP Flow Monitoring Project 4 Long Beach 2025

Prepared For:

Pedro Alvarez Project Manager

GHD

Proudly employee-owned | ghd.com

320 Goddard Way Suite 200 Irvine CA 92618 USA D 1 949 585 5262 | E Pedro.alvarez@ghd.com

Prepared By:

ADS, LLC

15201 Springdale St.

Huntington Beach, CA 92649

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GHD Group entered into an agreement with ADS Environmental Services to conduct flow monitoring at (4) four locations in the Long Beach Sanitary Collection System. This Project 4 was originally intended for six (6) locations, but 2 were eliminated due to field conditions and approved by GHD. The study was scheduled for a minimum period of (14) fourteen days. (21) Twenty-one days of data are included in this report. Once in place, the flow monitoring equipment was used to measure depth, velocity, and to quantify flows. The objective of this study was to confirm flows for planning purposes.

Project Scope

The scope of this study involved using a flow monitor to quantify wastewater flow at the designated locations for the 21-day time period. Specifically, the study included the following key components.

• Investigate the proposed flow-monitoring sites for adequate hydraulic conditions

• Flow monitor installations

• Flow monitor confirmations and data collections

• Flow data analysis Equipment installation was completed on November 12, 2025. The monitoring began on November 13, 2025 and was completed on December 3, 2025. Upon completion of the study, equipment was removed from the system.

The ADS Triton+ monitor was selected for this project. This flow monitor is an area velocity flow monitor that uses both the Continuity and Manning's equations to measure flow.

The ADS Triton+ monitor consists of data acquisition sensors and a battery-powered microcomputer. The microcomputer includes a processor unit, data storage, and an on-board clock to control and synchronize the sensor recordings. The monitor was programmed to acquire and store depth of flow and velocity readings at 5-minute intervals.

The Triton+ monitor features cross-checking using multiple technologies in each sensor for continuous running of comparisons and tolerances. The Triton+ monitor can support two (2) sets of sensors. The sensor option used for this project was:

The Peak Combo Sensor installed at the bottom of the pipe includes three types of data acquisition technologies.

The up looking ultrasonic depth uses sound waves from two independent transceivers to measure the distance from the sensor upward toward the flow surface; applying the speed of sound in the water and the temperature measured by

Scope and Methodology

Introduction

Flow Monitoring Equipment

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sensor to calculate depth.

The pressure depth is calculated by using a piezo-resistive crystal to determine the difference between hydrostatic and atmospheric pressure. The pressure sensor is temperature compensated and vented to the atmosphere through a desiccant filled breather tube.

To obtain peak velocity, the sensor sends an ultrasonic signal at an angle upward through the widest cross-section of the oncoming flow. The signal is reflected by suspended particles, air bubbles, or organic matter with a frequency shift proportional to the velocity of the reflecting objects. The reflected signal is received by the sensor and processed using digital spectrum analysis to determine the peak flow velocity.

Installation

Installation of flow monitoring equipment typically proceeds in four steps. First, the site is investigated for safety and to determine physical and hydraulic suitability for the flow monitoring equipment. Second, the equipment is physically installed at the selected location. Third, the monitor is tested to assure proper operation of the velocity and depth of flow sensors and verify that the monitor clock is operational and synchronized to the master computer clock. Fourth, the depth and velocity sensors are confirmed and line confirmations are performed.

In pipes up to 42 inches in diameter, the sensors were mounted on expandable stainless steel rings, inserted at least a foot upstream into influent pipes and tightened against the inside walls of the pipes. Influent pipe installations reduce the influences of turbulence and backwater often caused by changes in channel geometry in manholes.

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Data Collection, Confirmation, and Quality Assurance

Data collection was done remotely via wireless connect on a weekly basis via ADS Field Representatives. During the monitoring period, field crews visit each monitoring location to verify proper monitor operation and document field conditions. The following quality assurance steps are taken to assure the integrity of the collected data:

Measure power supplies: monitors were powered by dry cell battery packs. Voltages were recorded and battery packs replaced, as necessary. Separate batteries provided back-up power to memory allowing primary batteries to be replaced without loss of data.

Clock synchronization: Field crews synchronized monitor clocks to master clocks.

Confirm depth and velocity readings: Field crews descended into meter manholes to manually measure depths and velocities and compare them meter readings to confirm that they agreed. They also measured silt levels, if any, in the inverts of the pipes. Silt areas were subtracted from flow areas to compute true areas of flow.

Confirm average velocities through cross-sectional velocity profiles: Since ADS velocity sensors measure peak velocity, field crews collected cross-sectional velocity profiles in order to develop a relationship between peak and average velocity in lines that meet the hydraulic criteria.

Upload and Review Data: Data collected from the monitors were uploaded and reviewed by a Data Analyst for completeness, outliers and deviations in the flow patterns, which indicate system anomalies or equipment failure.

There are two main equations used to measure open channel flow: the Continuity Equation and the Manning Equation.

The Continuity Equation, which is considered the most accurate, can be used if both depth of flow and velocity are available. In cases where velocity measurements are not available or not practical to obtain, the Manning Equation can be used to estimate velocity from the depth data based on certain physical characteristics of the pipe (i.e. the slope and roughness of the pipe being measured). However, the Manning equation assumes uniform, steady flow hydraulic conditions with non-varying roughness, which are typically invalid assumptions in most sanitary sewers. The Continuity Equation was used exclusively for this study.

Continuity Equation The Continuity Equation states that the flow quantity (Q) is equal to the wetted area (A) multiplied by the average velocity

(V) of the flow.

Flow Quantification Methods

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Q = A * V

This equation is applicable in a variety of conditions including backwater, surcharge, and reverse flow.

Data Analysis

A flow monitor is typically programmed to collect data at 15-minute intervals throughout the monitoring period. The monitor stores raw data consisting of (1) the ultrasonic depth, (2) the peak velocity and (3) the pressure depth. The data is imported into ADS's proprietary software and is examined by a data analyst to verify its integrity. The data analyst also reviews the daily field reports and site visit records to identify conditions that would affect the collected data.

Velocity profiles and the line confirmation data developed by the field personnel are reviewed by the data analyst to identify inconsistencies and verify data integrity. Velocity profiles are reviewed and an average to peak velocity ratio is calculated for the site. This ratio is used in converting the peak velocity measured by the sensor to the average velocity used in the Continuity equation. The data analyst selects which depth sensor entity will be used to calculate the final depth information.

Silt and/or debris are often present in sewer lines. When present, silt levels are measured at each site visit. They are reviewed by the data analyst and representative silt levels established. Silt reduces the cross sectional area of the flow where as debris causes depth to become deeper and slower. Calculated flow should remain consistent in both hydraulic conditions.

Debris may result in reduced line capacity.

Occasionally the velocity sensor's performance may be compromised resulting in invalid readings sporadically during the monitoring period. This is generally caused by excessive debris (silt) blocking the sensor's crystals, shallow flows (~< 1") that may drop below the top of the sensor or very clear flows lacking the particles needed to measure rate. In order to use the Continuity equation to quantify the flow during these periods, a Data Analyst and/or Engineer will use the site's historical pipe curve (depth vs. velocity) data along with valid field confirmations to reconstitute and replace the false velocity recordings with expected velocity readings for a given historical depth along the curve.

Selections for the above parameters can be constant or can change during the monitoring period. While the data analysis process is described in a linear manner, it often requires an iterative approach to accurately complete.

Data Presentation

This type of flow monitoring project generates a large volume of data. To facilitate review of the data, results have been provided in graphical and tabular formats. The flow data is presented graphically in the form of scattergraphs and hydrographs. Hydrographs are based on 15-minute averaging. Tables are provided in daily average format. These tables show the flow rate for each day, along with the daily minimum and maximums, the times they were observed, the total daily flow, and total flow for the month (or monitoring period). The following explanation of terms may aid in interpretation of the tables and hydrographs.

DFINAL - Final calculated depth measurement (in inches)

QFINAL - Final calculated flow rate (in MGD)

VFINAL - Final calculated flow velocity (in feet per second)

REPORT TOTAL - Total volume of flow recorded for the indicated time period (in MG)

Data Analysis and Presentation

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K11-037 Site Commentary

SITE INFORMATION

OBSERVATIONS

Site K11-037 functioned under normal conditions during the study Thursday, 13 November 2025 to Wednesday, 03 December 2025.

No surcharge conditions were experienced at this location. No backwater conditions were observed.

This site was positioned upstream of site L11-047. A review of flow balancing indicated no problems.

Average flow depth, velocity, and quantity data observed during Thursday, 13 November 2025 to Wednesday, 03 December 2025, along with observed minimum and maximum data, are provided in the following table.

Observed Flow Conditions

Item DFINAL (in) VFINAL (ft/s) QFINAL (MGD - Total

MG)

Average 3.46 1.84 0.178

Minimum 2.23 1.06 0.056

Maximum 5.47 3.16 0.443

Min Time 11/26/2025 4:10:00 AM 11/16/2025 3:15:00 AM 11/26/2025 4:10:00 AM

Max Time 11/15/2025 12:35:00 PM 11/15/2025 12:00:00 PM 11/15/2025 9:05:00 AM

Based upon the quality and consistency of the observed flow depth and velocity data, the Continuity equation was used to calculate flow rate and quantities during the monitoring period.

Values in the Observed Flow Conditions and tabular report are based on the 5-minute average.

Values in the graphical reports are based on the fifteen minutes average.

DATA UPTIME

Data uptime observed during Thursday, 13 November 2025 to Wednesday, 03 December 2025 is provided in the following table:

Percent Uptime DFINAL (in) 100

VFINAL (ft/s) 100

QFINAL (MGD - Total MG) 100

Pipe Round (8 in H)

Silt 0.00 (in)

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ADS Site Report FM Initials:Project Name:

Site Name:

City:

Access: Type of System:

Sanitary

Investigation Information:

Manhole Depth:

Manhole Material /

Pipe Material / Condition:

Commercial

Oxygen:

Safety Notes:

Date/Time of Investigation:

Site Hydraulics:

Upstream Input: (L/S, P/S)

Upstream Manhole:

Downstream Manhole:

Depth of Flow:

Range (Air DOF):

Peak Velocity:

Silt: Inches fps

Cross Section Installation Information

Installation Type: Standard Sensors Devices: Ultrasonic/Velocity/Pressure Surcharge Height:

Rain Gauge Zone:

Yes No ? Distance Trunk Lift / Pump Station

WWTP

Other

Monitor Type

Pipe Height:

Pipe Width:

Data Acquisition Manhole ID

Quality Form

Address/Location:

VM

Drive Storm Combined

X

Manhole Information:Investigation Information:

Condition

Land Use:

OtherResidential Industrial

NN

Other Information:

Additional Site Information / Comments:

x x x x

Monitor Model x

Install Date:

Agency:

Triton +

Peak Doppler

Backup

LongBch.GHD.TFM.CA25 Long Beach

K11-037

Good Straight through flow

Not investigated

0.25"

1.39

9'

Brick/Good

VCP/Good

2.38

11/11/2025 @ 2:20 AM

Standard Traffic Control with No Safety Concerns

722 Cherry Ave

Not Investigated

Sensor Location

9' 8.

x

.0

8.00

8.00

0.00

Plan N

H2S: LEL: CO:20.9 0 0 0

2 man crew required and one blower is to be operated at all times.

Manual/Wireless Collect

ADS Site Location

ADS Site Location flow dir.

Long Beach

11/11/2025

K11-037

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800-633-7246 www.adsenv.com

Hydrograph Report

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Scattergraph Report

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Daily Tabular Report

11/13/2025 00:00 - 12/03/2025 23:59 K11-037Pipe: Round (8 in H), Silt0.00 in

DFINAL (in) VFINAL (ft/s) QFINAL (MGD - Total MG) Date Time Min Time Max Avg Time Min Time Max Avg Time Min Time Max Avg Total

11/13/2025 01:35 2.36 21:45 4.39 3.46 04:25 1.17 21:45 2.26 1.80 04:25 0.066 21:45 0.287 0.173 0.173 11/14/2025 03:00 2.40 19:00 4.92 3.57 03:00 1.16 19:20 3.06 1.87 03:00 0.066 19:20 0.430 0.189 0.189 11/15/2025 05:20 2.55 12:35 5.47 3.74 04:45 1.25 12:00 3.16 2.02 02:35 0.079 09:05 0.443 0.221 0.221 11/16/2025 04:35 2.27 21:15 4.36 3.42 03:15 1.06 11:20 2.28 1.83 04:35 0.057 11:20 0.287 0.176 0.176 11/17/2025 02:35 2.37 18:35 4.76 3.44 02:35 1.15 18:35 2.40 1.86 02:35 0.064 18:35 0.336 0.178 0.178 11/18/2025 04:25 2.38 19:50 3.98 3.38 03:00 1.20 19:50 2.20 1.79 04:10 0.069 19:50 0.246 0.166 0.166 11/19/2025 01:55 2.34 20:05 4.45 3.36 02:30 1.13 20:05 2.30 1.78 03:10 0.064 20:05 0.296 0.165 0.165 11/20/2025 02:35 2.29 21:45 5.05 3.46 02:55 1.13 21:40 2.89 1.84 02:35 0.061 21:40 0.413 0.180 0.180 11/21/2025 04:15 2.71 02:40 4.70 3.56 00:55 1.39 02:00 3.00 1.93 04:15 0.093 02:00 0.408 0.190 0.190 11/22/2025 03:25 2.42 18:55 4.67 3.40 03:30 1.18 18:55 2.97 1.82 03:30 0.068 18:55 0.407 0.172 0.172 11/23/2025 04:05 2.49 10:25 4.57 3.44 04:20 1.25 10:25 2.31 1.82 04:20 0.075 10:25 0.309 0.174 0.174 11/24/2025 02:30 2.38 09:40 4.30 3.41 02:25 1.17 14:05 2.19 1.81 02:25 0.066 09:40 0.269 0.171 0.171 11/25/2025 03:40 2.35 19:30 4.41 3.39 03:45 1.13 20:15 2.28 1.80 03:40 0.063 19:30 0.288 0.170 0.170 11/26/2025 04:10 2.23 19:50 4.38 3.43 04:10 1.10 19:50 2.30 1.84 04:10 0.056 19:50 0.291 0.176 0.176 11/27/2025 03:20 2.44 12:55 4.93 3.38 02:55 1.17 11:35 2.50 1.78 03:20 0.068 12:55 0.363 0.168 0.168 11/28/2025 03:10 2.39 09:40 4.31 3.41 03:05 1.17 09:40 2.28 1.80 03:10 0.066 09:40 0.283 0.170 0.170 11/29/2025 03:50 2.40 11:35 4.35 3.45 03:50 1.19 18:00 2.33 1.84 03:50 0.068 11:35 0.286 0.177 0.177 11/30/2025 04:20 2.50 11:40 4.53 3.51 04:20 1.26 14:00 2.34 1.87 04:20 0.076 11:40 0.299 0.184 0.184 12/01/2025 03:25 2.71 18:40 4.41 3.54 03:30 1.31 18:40 2.29 1.88 03:30 0.088 18:40 0.292 0.184 0.184 12/02/2025 04:05 2.35 19:05 4.70 3.47 04:10 1.14 19:05 2.84 1.82 04:10 0.063 19:05 0.391 0.176 0.176 12/03/2025 04:15 2.37 20:10 4.14 3.49 02:55 1.18 08:35 2.20 1.83 04:15 0.066 20:10 0.257 0.178 0.178

DFINAL

(in)

VFINAL

(ft/s)

QFINAL

(MGD -

Total MG) Total 3.740

Average 3.46 1.84 0.178

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K13-037

Site K13-037 functioned under normal conditions during the study Thursday, 13 November 2025 to Wednesday, 03 December 2025.

Surcharge conditions were briefly experienced at this location on November 14, 15, 20, and 21. No backwater conditions were observed.

This site was positioned downstream of site L12-057. A review of flow balancing indicated no problems.

Average flow depth, velocity, and quantity data observed during Thursday, 13 November 2025 to Wednesday, 03 December 2025, MG)

Average 9.36 1.53 0.811

Minimum 6.78 0.75 0.262

Maximum 18.66 2.65 2.210

Min Time 11/28/2025 4:05:00 AM 11/25/2025 3:35:00 AM 11/25/2025 3:35:00 AM

Max Time 11/15/2025 9:05:00 AM 11/21/2025 2:05:00 AM 11/21/2025 2:05:00 AM

Based upon the quality and consistency of the observed flow depth and velocity data, the Continuity equation was used to calculate

Data uptime observed during Thursday, 13 November 2025 to Wednesday, 03 December 2025 is provided in the following table:

Pipe Elliptical (15.75 in H x 15 in W)

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Site Name:

City:

Access: Type of System:

Sanitary

Investigation Information:

Manhole Depth:

Manhole Material /

Pipe Material / Condition:

Commercial

Oxygen:

Safety Notes:

Date/Time of Investigation:

Site Hydraulics:

Upstream Input: (L/S, P/S)

Upstream Manhole:

Downstream Manhole:

Depth of Flow:

Range (Air DOF):

Peak Velocity:

Silt: Inches fps

Cross Section Installation Information

Installation Type: Standard Sensors Devices: Ultrasonic/Velocity/Pressure Surcharge Height:

Rain Gauge Zone:

Yes No ? Distance Trunk Lift / Pump Station

WWTP

Other

Monitor Type

Pipe Height:

Pipe Width:

Data Acquisition Manhole ID

Quality Form

Address/Location:

VM

Drive Storm Combined

X

Manhole Information:Investigation Information:

Condition

Land Use:

OtherResidential Industrial

NN

Other Information:

Additional Site Information / Comments:

x x x

Monitor Model

Install Date:

Agency:

Triton +

Peak Doppler

Backup

LongBch.GHD.TFM.CA25 Long Beach

K13-037

Good Straight through flow

Not investigated

0.25"

0.93

19'

Brick/Good

VCP/Good

9.13

11/12/2025 @ 1:20 AM

Standard Traffic Control with No Safety Concerns

1301 Gardenia Ave

Not Investigated

Sensor Location

.7 x

.0

15.75

15.00

0.00

Plan N

H2S: LEL: CO:20.9 0 0 0

2 man crew required and one blower is to be operated at all times.

Manual/Wireless Collect

ADS Site Location

ADS Site Location flow dir.

Long Beach

11/12/2025

K13-037

AD 1-20

AD 1-21

AD 1-22

K13-037Pipe: Elliptical (15.75 in H x 15 in W), Silt0.00 in

11/13/2025 03:50 7.80 19:25 11.36 10.02 03:50 0.77 20:55 1.64 1.33 03:50 0.317 19:30 1.050 0.757 0.757 11/14/2025 03:45 8.02 19:20 18.32 10.37 03:15 0.77 19:30 2.37 1.41 03:45 0.330 19:30 1.965 0.842 0.842 11/15/2025 02:50 7.79 09:05 18.66 10.95 02:30 0.88 12:05 2.50 1.62 02:50 0.365 12:05 2.026 1.018 1.018 11/16/2025 05:20 7.22 11:35 11.28 9.47 03:30 0.97 11:45 2.04 1.57 03:30 0.367 11:40 1.285 0.847 0.847 11/17/2025 04:10 6.98 20:10 11.75 9.34 02:55 0.90 18:40 2.03 1.54 02:55 0.324 20:20 1.276 0.817 0.817 11/18/2025 03:50 6.95 21:20 10.26 9.12 03:15 0.91 20:05 1.89 1.50 03:15 0.329 20:05 1.075 0.766 0.766 11/19/2025 04:30 6.93 20:25 10.16 9.06 03:55 0.85 18:55 1.88 1.52 03:55 0.305 20:45 1.065 0.771 0.771 11/20/2025 03:50 6.79 21:55 17.62 9.38 04:20 0.87 21:20 2.15 1.59 04:20 0.302 21:55 1.738 0.845 0.845 11/21/2025 01:30 7.60 01:50 18.01 9.76 01:10 1.17 02:05 2.65 1.62 01:25 0.477 02:05 2.210 0.888 0.888 11/22/2025 04:15 7.03 13:10 10.93 9.22 03:20 0.87 11:05 1.86 1.50 03:20 0.322 11:40 1.120 0.780 0.780 11/23/2025 04:20 7.28 11:25 11.05 9.27 04:40 0.85 10:50 2.01 1.51 04:40 0.328 10:50 1.206 0.792 0.792 11/24/2025 04:15 7.09 12:10 10.18 9.11 04:15 0.84 18:40 1.75 1.44 04:15 0.305 10:00 0.975 0.736 0.736 11/25/2025 03:45 6.84 10:10 10.04 9.02 03:35 0.75 20:10 1.77 1.38 03:35 0.262 20:10 0.971 0.700 0.700 11/26/2025 04:20 6.89 10:10 10.07 9.06 04:00 0.95 19:35 1.91 1.57 04:20 0.334 19:35 1.062 0.793 0.793 11/27/2025 04:30 6.97 12:30 11.23 9.05 04:30 0.94 11:55 2.07 1.57 04:30 0.334 12:35 1.306 0.803 0.803 11/28/2025 04:00 6.78 11:35 10.53 8.89 03:25 0.78 11:25 1.94 1.49 03:55 0.268 11:25 1.141 0.748 0.748 11/29/2025 03:35 7.08 13:00 10.89 9.16 05:30 0.95 11:55 2.01 1.58 05:30 0.359 12:05 1.191 0.816 0.816 11/30/2025 05:10 7.10 11:55 10.74 9.27 04:45 0.96 13:50 1.99 1.61 04:45 0.357 11:50 1.170 0.842 0.842 12/01/2025 03:05 7.20 19:25 10.26 9.11 04:10 0.99 19:25 2.05 1.62 04:10 0.370 19:25 1.178 0.823 0.823 12/02/2025 03:40 6.80 19:25 10.32 8.99 03:40 0.91 19:25 2.01 1.62 03:40 0.313 19:25 1.162 0.815 0.815 12/03/2025 03:20 6.84 08:05 10.31 9.03 03:15 1.03 08:10 1.98 1.63 03:15 0.359 08:10 1.140 0.821 0.821

(in)

VFINAL

(ft/s)

QFINAL

(MGD -

Total MG) Total 17.021

Average 9.36 1.53 0.811

AD 1-23

L11-047

Site L11-047 functioned under normal conditions during the study Thursday, 13 November 2025 to Wednesday, 03 December 2025.

No surcharge conditions were experienced at this site. No backwater conditions were observed.

This site was positioned downstream of site K11-037 and upstream of site L12-057. A review of flow balancing indicated no problems.

Average flow depth, velocity, and quantity data observed during Thursday, 13 November 2025 to Wednesday, 03 December 2025, MG)

Average 3.78 1.71 0.185

Minimum 2.43 1.08 0.066

Maximum 5.85 2.44 0.432

Min Time 11/16/2025 3:35:00 AM 11/25/2025 3:45:00 AM 11/26/2025 4:15:00 AM

Max Time 11/15/2025 12:05:00 PM 11/15/2025 12:05:00 PM 11/15/2025 12:05:00 PM

Based upon the quality and consistency of the observed flow depth and velocity data, the Continuity equation was used to calculate

Data uptime observed during Thursday, 13 November 2025 to Wednesday, 03 December 2025 is provided in the following table:

Pipe Round (8 in H)

AD 1-24

Site Name:

City:

Access: Type of System:

Sanitary

Investigation Information:

Manhole Depth:

Manhole Material /

Pipe Material / Condition:

Commercial

Oxygen:

Safety Notes:

Date/Time of Investigation:

Site Hydraulics:

Upstream Input: (L/S, P/S)

Upstream Manhole:

Downstream Manhole:

Depth of Flow:

Range (Air DOF):

Peak Velocity:

Silt: Inches fps

Cross Section Installation Information

Installation Type: Standard Sensors Devices: Ultrasonic/Velocity/Pressure Surcharge Height:

Rain Gauge Zone:

Yes No ? Distance Trunk Lift / Pump Station

Pipe Width:

Data Acquisition Manhole ID

Quality Form

Address/Location:

VM

Drive Storm Combined

X

Manhole Information:Investigation Information:

Condition

Land Use:

OtherResidential Industrial

NN

Other Information:

Additional Site Information / Comments:

x x

Install Date:

Agency:

Triton +

Peak Doppler

Backup

LongBch.GHD.TFM.CA25 Long Beach

L11-047

Good Straight through flow

Not investigated

0.25"

1.47

7'-2'

Brick/Good

VCP/Good

2.50

11/11/2025 @ 1:40 AM

Standard Traffic Control with No Safety Concerns

839 Cherry Ave

Not Investigated

Sensor Location

7' -2

8.

x

.0

8.00

8.00

0.00

Plan N

H2S: LEL: CO:20.9 0 0 0

2 man crew required and one blower is to be operated at all times.

Manual/Wireless Collect

ADS Site LocationADS Site

Location flow dir.

Long Beach

11/11/2025

L11-047

AD 1-25

AD 1-26

AD 1-27

L11-047Pipe: Round (8 in H), Silt0.00 in

11/13/2025 04:10 2.48 19:10 4.47 3.65 01:40 1.18 19:10 2.01 1.70 01:40 0.071 19:10 0.260 0.176 0.176 11/14/2025 03:05 2.51 19:25 5.70 3.82 03:10 1.17 19:20 2.36 1.76 03:05 0.071 19:25 0.407 0.193 0.193 11/15/2025 02:40 2.65 12:05 5.85 4.08 04:50 1.23 12:05 2.44 1.85 02:30 0.081 12:05 0.432 0.224 0.224 11/16/2025 03:35 2.43 20:15 4.68 3.77 03:40 1.14 21:35 2.17 1.73 03:35 0.066 11:25 0.284 0.188 0.188 11/17/2025 03:45 2.46 18:40 4.72 3.75 03:45 1.18 18:25 2.17 1.74 03:45 0.069 18:40 0.297 0.187 0.187 11/18/2025 03:05 2.50 19:55 4.85 3.70 03:05 1.18 20:10 1.94 1.64 03:05 0.071 19:55 0.257 0.171 0.171 11/19/2025 02:00 2.55 20:05 4.95 3.69 03:15 1.12 20:10 2.13 1.66 03:15 0.070 20:10 0.312 0.174 0.174 11/20/2025 02:40 2.48 21:45 5.60 3.77 02:25 1.15 21:45 2.31 1.71 02:40 0.069 21:45 0.390 0.187 0.187 11/21/2025 04:20 2.82 02:05 5.55 3.92 04:20 1.34 02:05 2.34 1.77 04:20 0.095 02:05 0.391 0.198 0.198 11/22/2025 03:30 2.63 19:00 4.88 3.75 04:25 1.22 19:00 2.07 1.70 03:30 0.080 19:00 0.298 0.182 0.182 11/23/2025 04:15 2.66 17:50 4.70 3.74 04:10 1.23 10:35 2.03 1.71 04:10 0.080 10:30 0.277 0.182 0.182 11/24/2025 04:15 2.49 12:25 4.62 3.71 04:20 1.18 09:45 1.99 1.70 04:15 0.071 12:25 0.268 0.179 0.179 11/25/2025 04:00 2.53 18:55 4.78 3.74 03:45 1.08 18:55 2.03 1.66 04:00 0.066 18:55 0.285 0.178 0.178 11/26/2025 04:15 2.52 17:55 4.83 3.86 04:10 1.08 15:30 2.08 1.67 04:15 0.066 17:55 0.283 0.186 0.186 11/27/2025 05:00 2.66 13:00 5.26 3.81 03:15 1.11 14:20 2.17 1.62 03:15 0.074 13:00 0.333 0.180 0.180 11/28/2025 03:45 2.71 11:55 4.78 3.77 04:35 1.12 19:25 2.10 1.66 04:35 0.076 11:55 0.283 0.179 0.179 11/29/2025 04:45 2.56 13:55 4.77 3.77 04:45 1.15 14:15 2.26 1.71 04:45 0.072 14:15 0.302 0.186 0.186 11/30/2025 04:25 2.71 10:45 4.70 3.84 04:45 1.23 14:05 2.14 1.75 04:45 0.083 14:05 0.295 0.193 0.193 12/01/2025 03:55 2.80 18:45 4.59 3.81 03:40 1.30 07:50 2.07 1.75 03:55 0.092 18:50 0.271 0.189 0.189 12/02/2025 03:55 2.48 19:10 4.93 3.71 04:10 1.13 19:10 2.13 1.71 04:10 0.067 19:10 0.311 0.180 0.180 12/03/2025 04:20 2.49 20:15 4.60 3.76 04:00 1.18 20:15 2.02 1.71 04:20 0.071 20:15 0.271 0.184 0.183

(in)

VFINAL

(ft/s)

QFINAL

(MGD -

Total MG) Total 3.895

Average 3.78 1.71 0.185

AD 1-28

L12-057

Site L12-057 functioned under normal conditions during the study Thursday, 13 November 2025 to Wednesday, 03 December 2025.

No surcharge conditions were experienced at this site. No backwater conditions were observed.

This site was positioned downstream of site L11-047 and upstream of site K13-037. A review of flow balancing indicated no problems.

Average flow depth, velocity, and quantity data observed during Thursday, 13 November 2025 to Wednesday, 03 December 2025, MG)

Average 3.92 1.58 0.209

Minimum 2.63 1.00 0.075

Maximum 6.05 2.27 0.491

Min Time 11/16/2025 3:45:00 AM 11/25/2025 3:55:00 AM 11/25/2025 3:55:00 AM

Max Time 11/21/2025 1:50:00 AM 11/15/2025 12:15:00 PM 11/21/2025 1:50:00 AM

Based upon the quality and consistency of the observed flow depth and velocity data, the Continuity equation was used to calculate

Data uptime observed during Thursday, 13 November 2025 to Wednesday, 03 December 2025 is provided in the following table:

Pipe Round (10 in H)

AD 1-29

Site Name:

City:

Access: Type of System:

Sanitary

Investigation Information:

Manhole Depth:

Manhole Material /

Pipe Material / Condition:

Commercial

Oxygen:

Safety Notes:

Date/Time of Investigation:

Site Hydraulics:

Upstream Input: (L/S, P/S)

Upstream Manhole:

Downstream Manhole:

Depth of Flow:

Range (Air DOF):

Peak Velocity:

Silt: Inches fps

Cross Section Installation Information

Installation Type: Standard Sensors Devices: Ultrasonic/Velocity/Pressure Surcharge Height:

Rain Gauge Zone:

Yes No ? Distance Trunk Lift / Pump Station

Pipe Width:

Data Acquisition Manhole ID

Quality Form

Address/Location:

VM

Drive Storm Combined

X

Manhole Information:Investigation Information:

Condition

Land Use:

OtherResidential Industrial

NN

Other Information:

Additional Site Information / Comments:

x x

Install Date:

Agency:

Triton +

Peak Doppler

Backup

LongBch.GHD.TFM.CA25 Long Beach

L12-057

Good Straight through flow

Not investigated

0.25"

1.80

4'-4"

Brick/Good

VCP/Good

3.13

11/11/2025 @ 12:00 AM

Standard Traffic Control with No Safety Concerns

1155 Cherry Ave

Not Investigated

Sensor Location

4' -4

.0 x

.0

10.00

10.00

0.00

Plan N

H2S: LEL: CO:20.9 0 0 0

2 man crew required and one blower is to be operated at all times.

Manual/Wireless Collect

ADS Site Location

ADS Site Location flow dir.

Long Beach

11/11/2025

L12-057

AD 1-30

AD 1-31

AD 1-32

L12-057Pipe: Round (10 in H), Silt0.00 in

11/13/2025 01:35 2.98 19:20 4.80 3.96 04:20 1.10 16:55 1.85 1.56 04:20 0.099 19:20 0.306 0.207 0.207 11/14/2025 04:15 3.01 19:35 5.58 4.03 04:15 1.13 19:30 2.15 1.60 04:15 0.101 19:30 0.435 0.220 0.220 11/15/2025 02:50 2.86 12:00 5.86 4.24 02:40 1.16 12:15 2.27 1.70 02:40 0.097 12:15 0.485 0.253 0.253 11/16/2025 03:45 2.63 11:35 4.58 3.88 03:45 1.07 11:10 1.86 1.59 03:45 0.079 11:10 0.287 0.208 0.208 11/17/2025 03:00 2.78 20:10 4.87 3.89 04:10 1.12 20:10 1.93 1.59 03:55 0.090 20:10 0.328 0.208 0.208 11/18/2025 03:30 2.79 20:05 4.43 3.82 04:10 1.12 20:05 1.86 1.55 04:00 0.092 20:05 0.280 0.197 0.197 11/19/2025 02:25 2.73 20:20 4.68 3.83 02:45 1.11 20:40 1.88 1.57 02:40 0.087 20:20 0.304 0.200 0.200 11/20/2025 02:15 2.65 21:55 5.59 3.91 02:25 1.06 21:55 2.10 1.58 02:25 0.080 21:55 0.425 0.211 0.211 11/21/2025 01:25 3.08 01:50 6.05 4.09 01:25 1.25 02:05 2.22 1.66 01:25 0.115 01:50 0.491 0.230 0.230 11/22/2025 03:45 2.91 13:35 4.57 3.89 03:45 1.16 13:35 1.84 1.57 03:45 0.099 13:35 0.288 0.205 0.205 11/23/2025 04:30 2.83 12:15 4.54 3.89 04:20 1.13 12:35 1.86 1.57 04:30 0.093 12:35 0.289 0.205 0.205 11/24/2025 04:30 2.71 14:20 4.40 3.87 04:30 1.08 18:55 1.80 1.55 04:30 0.083 18:55 0.265 0.201 0.201 11/25/2025 04:05 2.63 19:05 4.57 3.87 03:55 1.00 20:05 1.86 1.56 03:55 0.075 19:05 0.289 0.203 0.203 11/26/2025 04:25 2.68 20:05 4.57 3.92 04:20 1.05 19:00 1.89 1.59 04:20 0.080 20:05 0.292 0.209 0.209 11/27/2025 04:10 2.82 13:10 5.08 3.87 03:30 1.12 10:10 1.94 1.56 04:10 0.092 13:10 0.345 0.203 0.203 11/28/2025 03:20 2.79 12:05 4.46 3.82 03:20 1.12 09:50 1.84 1.56 03:20 0.090 12:05 0.275 0.198 0.198 11/29/2025 04:00 2.76 14:05 4.66 3.86 04:00 1.12 14:05 1.90 1.57 04:00 0.089 14:05 0.306 0.204 0.204 11/30/2025 05:00 2.89 14:10 4.69 3.94 04:50 1.15 14:25 1.91 1.60 05:00 0.097 14:15 0.308 0.212 0.212 12/01/2025 03:25 2.93 20:10 4.47 3.92 03:25 1.19 19:00 1.80 1.60 03:25 0.102 20:10 0.273 0.209 0.209 12/02/2025 04:25 2.70 19:25 4.63 3.86 03:55 1.10 07:20 1.89 1.57 04:25 0.084 19:25 0.297 0.201 0.201 12/03/2025 04:30 2.76 20:30 4.53 3.91 04:35 1.09 20:25 1.85 1.56 04:35 0.087 20:25 0.286 0.205 0.205

(in)

VFINAL

(ft/s)

QFINAL

(MGD -

Total MG) Total 4.390

Average 3.92 1.58 0.209

AD 1-33

800-633-7246 www.adsenv.com

LongBch.GHD.TFM.CA25

PCAP Flow Monitoring Project 5 Long Beach 2025

Final Report Submitted to GHD December 19, 2025

AD 1-34

Thursday, 13 November 2025 to Wednesday, 03 December 2025

Pedro Alvarez Project Manager

GHD

Proudly employee-owned | ghd.com 320 Goddard Way Suite 200 Irvine CA 92618 USA D 1 949 585 5262 | E Pedro.alvarez@ghd.com

SUBJECT: PCAP Flow Monitoring Project 5 - Long Beach 2025

Dear Mr. Alvarez, ADS is pleased to submit the report for the project referenced above completed on behalf of GHD. The metering was conducted at two (2) locations. The study was conducted during the period of Thursday, 13 November 2025 to Wednesday, 03 December 2025.

The report contains depth, velocity, and quantity hydrographs as well as daily long tables for the metering period. An Excel file containing depth, quantity, and velocity entities for the monitoring location in 5-minute format was provided previously.

In addition, we would be happy to further explain any details about the report that may seem unclear. Should you have any questions or comments, you may contact the Project Manager, Paul Mitchell at (714)-920-4418.

It has been our pleasure to be of service to you in the performance of this project. Thank you for choosing ADS products and services to meet your flow monitoring needs.

Sincerely, ADS ENVIRONMENTAL SERVICES

Justin Hatch Data Analyst

AD 1-35

PCAP Flow Monitoring Project 5 Long Beach 2025

Prepared For:

Pedro Alvarez Project Manager

GHD

Proudly employee-owned | ghd.com

320 Goddard Way Suite 200 Irvine CA 92618 USA D 1 949 585 5262 | E Pedro.alvarez@ghd.com

Prepared By:

ADS, LLC

15201 Springdale St.

Huntington Beach, CA 92649

AD 1-36

GHD Group entered into an agreement with ADS Environmental Services to conduct flow monitoring at (2) two locations in the Long Beach Sanitary Collection System. The study was scheduled for a minimum period of (14) fourteen days. (21) Twenty-one days of data are included in this report. Once in place, the flow monitoring equipment was used to measure depth, velocity, and to quantify flows. The objective of this study was to confirm flows for planning purposes

Project Scope

The scope of this study involved using a flow monitor to quantify wastewater flow at the designated locations for the

21-day time period. Specifically, the study included the following key components.

• Investigate the proposed flow-monitoring sites for adequate hydraulic conditions

• Flow monitor installations

• Flow monitor confirmations and data collections

• Flow data analysis Equipment installation was completed on November 12, 2025. The monitoring began on November 13, 2025 and was completed on December 3, 2025. Upon completion of the study, equipment was removed from the system.

The ADS Triton+ monitor was selected for this project. This flow monitor is an area velocity flow monitor that uses both the Continuity and Manning's equations to measure flow.

The ADS Triton+ monitor consists of data acquisition sensors and a battery-powered microcomputer. The microcomputer includes a processor unit, data storage, and an on-board clock to control and synchronize the sensor recordings. The monitor was programmed to acquire and store depth of flow and velocity readings at 5-minute intervals.

The Triton+ monitor features cross-checking using multiple technologies in each sensor for continuous running of comparisons and tolerances. The Triton+ monitor can support two (2) sets of sensors. The sensor option used for this project was:

The Peak Combo Sensor installed at the bottom of the pipe includes three types of data acquisition technologies.

The up looking ultrasonic depth uses sound waves from two independent transceivers to measure the distance from the sensor upward toward the flow surface; applying the speed of sound in the water and the temperature measured by

Scope and Methodology

Introduction

Flow Monitoring Equipment

AD 1-37

sensor to calculate depth.

The pressure depth is calculated by using a piezo-resistive crystal to determine the difference between hydrostatic and atmospheric pressure. The pressure sensor is temperature compensated and vented to the atmosphere through a desiccant filled breather tube.

To obtain peak velocity, the sensor sends an ultrasonic signal at an angle upward through the widest cross-section of the oncoming flow. The signal is reflected by suspended particles, air bubbles, or organic matter with a frequency shift proportional to the velocity of the reflecting objects. The reflected signal is received by the sensor and processed using digital spectrum analysis to determine the peak flow velocity.

Installation

Installation of flow monitoring equipment typically proceeds in four steps. First, the site is investigated for safety and to determine physical and hydraulic suitability for the flow monitoring equipment. Second, the equipment is physically installed at the selected location. Third, the monitor is tested to assure proper operation of the velocity and depth of flow sensors and verify that the monitor clock is operational and synchronized to the master computer clock. Fourth, the depth and velocity sensors are confirmed and line confirmations are performed.

In pipes up to 42 inches in diameter, the sensors were mounted on expandable stainless steel rings, inserted at least a foot upstream into influent pipes and tightened against the inside walls of the pipes. Influent pipe installations reduce the influences of turbulence and backwater often caused by changes in channel geometry in manholes.

AD 1-38

Data Collection, Confirmation, and Quality Assurance

Data collection was done remotely via wireless connect on a weekly basis via ADS Field Representatives. During the monitoring period, field crews visit each monitoring location to verify proper monitor operation and document field conditions. The following quality assurance steps are taken to assure the integrity of the collected data:

Measure power supplies: monitors were powered by dry cell battery packs. Voltages were recorded and battery packs replaced, as necessary. Separate batteries provided back-up power to memory allowing primary batteries to be replaced without loss of data.

Clock synchronization: Field crews synchronized monitor clocks to master clocks.

Confirm depth and velocity readings: Field crews descended into meter manholes to manually measure depths and velocities and compare them meter readings to confirm that they agreed. They also measured silt levels, if any, in the inverts of the pipes. Silt areas were subtracted from flow areas to compute true areas of flow.

Confirm average velocities through cross-sectional velocity profiles: Since ADS velocity sensors measure peak velocity, field crews collected cross-sectional velocity profiles in order to develop a relationship between peak and average velocity in lines that meet the hydraulic criteria.

Upload and Review Data: Data collected from the monitors were uploaded and reviewed by a Data Analyst for completeness, outliers and deviations in the flow patterns, which indicate system anomalies or equipment failure.

There are two main equations used to measure open channel flow: the Continuity Equation and the Manning Equation.

The Continuity Equation, which is considered the most accurate, can be used if both depth of flow and velocity are available. In cases where velocity measurements are not available or not practical to obtain, the Manning Equation can be used to estimate velocity from the depth data based on certain physical characteristics of the pipe (i.e. the slope and roughness of the pipe being measured). However, the Manning equation assumes uniform, steady flow hydraulic conditions with non-varying roughness, which are typically invalid assumptions in most sanitary sewers.