Larry Walker Associates, Stormwater Monitoring, Santa Clara River (available in the City Clerk's Reading File) — Santa Clarita City Council, June 23, 2026

2525 Ocean Park Blvd
Suite 216
Santa Monica, CA 90405
310.394.1036
www.lwa.com
March 26, 2026
Michele Arima
City of Santa Clarita
23920 Valencia Boulevard, Suite 295
Santa Clarita, CA 91355
[email protected]
Subject: Larry Walker Associates Response to Proposal # ES-25-26-20 for Stormwater Monitoring Program and NPDES Permit Compliance
Dear Ms. Arima,
Larry Walker Associates (LWA) is pleased to provide the enclosed proposal to provide program implementation monitoring services for the Coordinated Integrated Monitoring Program (CIMP) for the Upper Santa Clara River (USCR).

LWA and its team of skilled partners (LWA Team) bring deep familiarity with the regulatory framework governing this program, including the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Permit Order No. R4-2021-0105, the applicable total maximum daily loads (TMDLs), and the multi-agency coordination requirements that make this program uniquely complex.

The LWA Team has a proven record of implementing watershed-scale monitoring programs that meet the technical rigor, scheduling demands, and reporting requirements of the Los Angeles Regional Water Quality Control Board. We understand the critical importance of independent wet weather event tracking, real-time sampling coordination with Los Angeles County, and delivering defensible data that supports both TMDL compliance tracking and Annual Report obligations.

Our proposal addresses all twelve scope elements from dry and wet weather monitoring and bacteria TMDL sampling to laboratory analysis, toxicity testing, Quality Assurance Project Plan (QAPP) development, and reporting and includes our approach to managing potential new NPDES Permit requirements that may arise during the contract term.

As Vice President of LWA, I am legally authorized to bind the proposal and will represent the LWA Team during the selection process. I appreciate your consideration of our proposal and welcome the opportunity to discuss our approach and experience. This proposal represents a firm offer valid for 120 days from the date of submission.

Please feel free to contact me at (310) 743-6235 or [email protected] with any questions or information concerning this proposal.

S
incerely,
C
hris Minton, Vice President
Larry Walker Associates, Inc.

RESPONSE FILE
Prepared for:

City of Santa Clarita Prepared by:

Larry Walker Associates, Inc
in Association with Tetra Tech
March 26, 2026
Stormwater Monitoring Program
and NPDES Permit Compliance
(ES-25-26-20)
*Cost File provided in separate submittal

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Table of Contents
1 INTRODUCTION _______________________________________________________ 2

1.1 LWA Background ____________________________________________________ 3

1.2 LWA Team Overview _________________________________________________ 4

1.3 History of Collaboration _______________________________________________ 5 2 REFERENCES __________________________________________________________ 5 3 PLAN OF STUDY/SCOPE OF WORK ________________________________________ 16 4 SCHEDULE ___________________________________________________________ 33 5 PROGRAM MANAGEMENT ______________________________________________ 38

5.1 Communication ____________________________________________________ 38

5.2 Schedule Compliance _______________________________________________ 38

5.3 Budget and Project Staﬃng ___________________________________________ 39

5.4 Subconsultant Coordination __________________________________________ 39

5.5 Quality Assurance and Quality Control __________________________________ 39 6 PERSONNEL, EQUIPMENT AND FACILITIES _________________________________ 41 7 SUB-CONSULTANTS ____________________________________________________ 45

7.1 Subconsultant Project Experience ______________________________________ 46

7.2 Subconsultant Staﬀ Qualiﬁcations ______________________________________ 48 8 OPTIONAL SPECIAL STUDIES _____________________________________________ 51

8.1 New NPDES Permit Requirements and Optional BMP Monitoring _____________ 53

8.2 Iron Study _________________________________________________________ 53

8.3 LREC 1 ____________________________________________________________ 53

8.4 Natural Source Exclusion _____________________________________________ 55

8.5 DNA/RNA Test Lab __________________________________________________ 56

8.6 Mercury Source Study _______________________________________________ 56

8.7 Pesticide Study _____________________________________________________ 57

Attachments
Attachment A. Resumes

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1 Introduction
Larry Walker Associates, Inc. (LWA) and our partners (the LWA Team or Team) are pleased to submit our response to the City of Santa Clarita (City) Request for Proposals (RFP) for the Coordinated Integrated Monitoring Program (CIMP) Implementation (Proposal # ES-20-21-30). The LWA Team is composed of program service providers LWA and Tetra Tech, with laboratory services provided by Euroﬁns, Physis, Nautilus Environmental, Pat-Chem Laboratories, Enthalpy Analytical, and LuminUltra Technologies. LWA Team key personnel and roles are provided in Section 6, and descriptions of the LWA Team subconsultants, including their services and expertise, are presented in Section 7. Members of the LWA Team have provided watershed monitoring services for over 20 years in Southern California, including the Upper Santa Clara River (USCR) watershed. LWA has assembled a project team with the breadth of knowledge and experience necessary to provide the requested services to:

1. Address the requirements of the Municipal Separate Storm Sewer System (MS4) Permit.

2. Provide analysis and reporting to support eﬀective implementation to achieve the goals of the Watershed Management Program (WMP) and Total Maximum Daily Loads (TMDLs).

3. Utilize regulatory and technical approaches to develop and implement special studies that address the underlying regulations driving WMP projects and challenges associated with compliance.

LWA has an established record of implementing complex watershed monitoring programs and brings a proven approach to cost-eﬀectively supporting our clients’ needs. Experience leading and managing these programs is imperative to the successful implementation of the CIMP; however, understanding why the data are being collected and how they can be used is equally crucial.

The LWA Team has completed numerous projects, including for the City and County of Los Angeles (County), that 1) demonstrate our qualiﬁcations and experience, 2) provide a record of past performance, and 3) highlight our ability to deliver on monitoring and reporting projects of various sizes/complexities. As highlighted in Section 2.0, the LWA Team brings unique qualiﬁcations that include:
• Utilizing our comprehensive understanding of the MS4 Permit and watershed-speciﬁc history to develop numerous CIMPs (including the USCR CIMP and USCR CIMP Update), creating approaches for key components of CIMPs adopted countywide, and leading monitoring and reporting for numerous CIMP groups.
• Developing the 2016 EWMP and 2021 WMP , including creating approaches to gain deemed compliance status based on the 2020 State Water Resources Control Board (State Board) Order. • Detailed knowledge of TMDLs gained by supporting our client’s engagement with Los Angeles Regional Water Quality Control Board (Regional Board) and United States Environmental Protection Agency (USEPA) staﬀ on the development or amendment of TMDLs in the region over the past 20 years.
• Fluency with the MS4 Permit requirements gained through our support to Permittees during MS4 Permit negotiations.
• Long-standing relationships with the Regional Board and State Board that earned the LWA Team a reputation for unbiased and technically astute work and gained the trust of the regulators.

A hallmark of LWA’s work includes bringing regulatory expertise to monitoring programs and special study design and implementation. The CIMP and associated contract provide an important vehicle that the City

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and County can utilize to build the technical and regulatory justiﬁcation to revise underlying regulations that drive the projects and costs associated with the WMP . The LWA Team will identify speciﬁc options for special studies, the anticipated beneﬁts, and associated implementation and acceptance challenges and work with the CIMP Group to select studies for implementation. In identifying and selecting studies, it is imperative to fully understand the end goals to avoid spending resources on science for the sake of science. As such, the cornerstone of our Team’s approach is to start by clearly identifying the issues being addressed and the intended application and goals of the study. As demonstrated in our references (Section 2), detailed special study approach (Section 8), and resumes (Attachment A), our Team has conducted numerous special studies in the Los Angeles region related to bacteria, metals, and ammonia.

Our Team’s study approach generally consists of:

Working with the USCR CIMP Group to identify opportunities to develop and implement studies that will clearly support regulatory relief from inappropriate water quality standards (WQSs) and/or directly support TMDL implementation eﬀorts (e.g., re-evaluation of WQSs and development of site-speciﬁc objectives [SSOs], bacteria source tracking and utilization of Quantitative Microbial Risk Assessment [QMRA]/natural source exclusion [NSE]):
• Building upon previous work conducted by the Group and other stakeholders. • Where available, using established regulatory guidance to inform study design. • Developing work plans to identify the study’s purpose, hypotheses to be tested, study approach and methods, speciﬁc tasks, limitations of the study, and a quality assurance/quality control (QA/QC), data analysis, and reporting plan.
• For highly specialized or controversial work, identifying and utilizing an independent technical advisory committee (TAC) to review the work plan and subsequent work products, as needed. • Working with regulatory agencies to navigate the regulatory process to ensure the appropriate use of the generated information to revise the Basin Plan and/or justify TMDL revisions. • Conducting meetings to provide presentations and progress to the USCR CIMP Group, regulators, and other stakeholders and incorporate comments into the special studies.

For each of our Team’s completed special studies, relationships with staﬀ in regulatory agencies and leading scientiﬁc and policy experts were critical to success. While our Team’s special studies employed innovative approaches, the most important outcome is that they have assisted municipalities in achieving their ultimate goal – regulatory compliance. From the onset of study development, critical policy considerations are examined, including the underlying Basin Plan provisions, the dynamics of the Regional Board, potential constraints that may aﬀect USEPA approval (if needed), and precedent. This approach has led to special studies that successfully resulted in Basin Plan Amendments (BPA) adopting SSOs for the Santa Clara River, Calleguas Creek, and Los Angeles River watersheds. The studies conducted by LWA form the basis for the only SSOs incorporated into the Basin Plan and TMDLs. While many ﬁrms can demonstrate experience with studies, no other team can match our record of changing regulations through studies.

1.1 LWA Background
LWA is a privately owned California corporation and a certiﬁed Women-Owned Business Enterprise, providing consulting services ranging from highly specialized water quality, stormwater, and watershed management to traditional wastewater engineering. As a ﬁrm of engineers, scientists, and experts in water quality science and regulation, we have the insight and foresight that comes only with years of

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experience implementing local, state, and federal environmental laws and regulations. Headquartered in Davis, LWA currently has over 80 professional and support staﬀ, with regional oﬃces located in Santa Monica, San Diego, Ventura, San Luis Obispo, Berkeley, and Yreka, as well as Seattle, Washington. Over the past 46 years, LWA has leveraged our expertise in environmental permit compliance to assist municipal clients with developing solutions to complex regulatory challenges that meet their needs and are approvable by Regional Water Boards, the State Board, and the USEPA. We have developed stormwater solutions for multiple Southern California cities and counties, including, but not limited to, the cities of Santa Clarita, Los Angeles, Camarillo, Thousand Oaks, San Diego, and the counties of Los Angeles, Ventura, San Diego, and Riverside; as well as local Watershed Management Groups (WMGs), including the Malibu Creek and Calleguas Creek watersheds. Additionally, LWA staﬀ ﬁll several leadership roles in the California Stormwater Quality Association (CASQA), California Association of Sanitation Agencies (CASA), and the California Water Environment Association (CWEA). Speciﬁc experience and qualiﬁcations supporting this eﬀort include:
• Water Quality Monitoring. LWA merges real-world monitoring experience with our in-depth knowledge of the MS4 Permit and TMDLs to craft and implement eﬀective, eﬃcient monitoring programs that support agencies in answering key management questions. LWA’s monitoring experience is extensive and includes managing programs for stormwater agencies, watershed groups, and agricultural coalitions throughout California. • Regulatory Assistance. LWA supports stormwater, wastewater, and agricultural clients in evaluating, interpreting, and developing regulatory solutions for complex water quality issues. LWA is recognized in the region and across California as a leader in supporting clients negotiating their MS4 Permits and TMDLs. We have worked with staﬀ from the USEPA, State Board, and various Regional Water Boards to eﬀect changes in regulatory outcomes.
• Pollutant-Based Programs. LWA’s pollutant-based work includes the development of targeted management approaches and programs for bacteria, trash, nutrients, toxicity, organophosphate and organochlorine pesticides, pyrethroids, metals, mercury, and sediments. • Stormwater Program Management and Implementation. LWA’s range of expertise to assist our clients with the development and implementation of stormwater programs includes overall program management and tracking, education and outreach, illicit discharge detection and elimination, construction, pollution prevention/good housekeeping, post-construction, green infrastructure standards, monitoring, program assessment, ﬁnancial analyses and fee development, and reporting. LWA’s guidance and implementation tools and templates reﬂect our real-world practical experience.

1.2 LWA Team Overview
Implementing the CIMP requires eﬀective management of diverse challenges. Our proposed approach to implementing the scope of services, detailed in Section 3, is intended to actively address those challenges.

The LWA Team understands the cost-eﬀective objectives of this project and will implement the CIMP to gather high-quality monitoring data to: (1) address the requirements of the Los Angeles Regional MS4 Permit embodied in the USCR CIMP; (2) provide analysis of the data to support eﬀective planning and implementation to achieve the goals of the WMP and TMDLs; and (3) capitalize on opportunities to eﬀect meaningful regulatory changes. The team will be led by LWA, which has provided monitoring, regulatory, and technical services in support of stormwater programs for decades.

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1.3 History of Collaboration
LWA and Tetra Tech share a proven track record of successful collaboration on complex stormwater monitoring programs in the Los Angeles region.

Most notably, the two ﬁrms have worked together on both the Upper Los Angeles River (ULAR) CIMP and the USCR CIMP , demonstrating a well- established working relationship built on coordination, reliability, and technical expertise.

On the ULAR CIMP , Tetra Tech provided comprehensive monitoring support to the City of Los Angeles and the Upper Los Angeles River WMG with the implementation of the approved program. This included conducting stormwater sampling across outfall and receiving water sites, accommodating a variety of sampling needs, including three-hour composite samples, grab samples, and Isco autosamplers. Tetra Tech coordinated directly with LWA to fulﬁll sampling personnel needs, including nighttime sampling events required to meet monitoring deadlines and capture ﬁrst-ﬂush events and worked closely with laboratories to ensure sample hold times were met.

This same collaborative model was carried forward on the USCR CIMP , where Tetra Tech again provided monitoring support to the City and the USCR WMG. The scope included dry- and wet-weather sampling at 13 outfall and receiving water sites, using the same range of sampling methodologies. For this eﬀort, Tetra Tech expanded coordination to include additional subconsultants alongside LWA to meet sampling personnel demands. Together, these projects reﬂect LWA's and Tetra Tech's ability to function as a cohesive, responsive team under demanding ﬁeld conditions, a foundation that positions the team for continued success on future monitoring eﬀorts.
2 References
Our Team’s reputation is a direct result of our professional and qualiﬁed staﬀ and our commitment to fostering long-term relationships built on trust with our clients. We have completed numerous relevant projects for local governments, including the City and the County, that demonstrate our qualiﬁcations and experience, provide a record of past performance, and highlight our ability to deliver monitoring and reporting projects of various sizes/complexities. The LWA Team’s highly relevant Southern California projects are listed in Table 1, with detailed project descriptions following the table. We can readily provide references attesting to our expertise, professional commitment, and proven processes for delivering projects on time and on budget, and to the complete satisfaction of our clients.

LWA and Tetra Tech
have a history of
successful collaboration
in Region 4

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Table 1. LWA Team Relevant Project Experience Summary
Project Name
Project descriptions provided below and in
Section 7.1
Scope of Services Additional
Experience
Team
Members
Stormwater Outfall Monitoring
Receiving Water Monitoring
TMDL Compliance Monitoring
Non-Stormwater Outfall Monitoring &
Source Identiﬁcation
Reporting and Data Management
Quality Assurance Project Plan (QAPP)
Laboratory Analysis (including Toxicity)
Special Studies
Creative Approaches/Modiﬁcations
NPDES Permit and/or TMDL Support
Regulator Engagement and Negotiation
LWA
Tetra Tech

1. CIMP Implementation and Reporting Services ● ● ● ● ● ● ● ● ● ● LWA

2. LA Region CIMP Development Services ● ● ● ● ● ● ● ● ● ● LWA & Tetra Tech

3. Malibu Creek Watershed CIMP ● ● ● ● ● ● ● ● ● ● ● LWA & Tetra Tech

4. Calleguas Creek Watershed TMDL Monitoring
and Special Studies ● ● ● ● ● ● ● ● ● ● ● LWA

5. LA River Bacteria Source Investigation Study
and Bacteria TMDL Development and
Implementation
● ● ● ● ● ● ● ● ● ● LWA

6. LA Region Site-Speciﬁc Objective Special
Studies ● ● ● ● ● ● ● ● LWA

7. LA Countywide MS4 NPDES Permit Renewal
Support ● ● ● ● ● LWA

8. On-Call Specialized and Expert Services for
TMDLs and Regulatory Support ● ● ● ● ● ● LWA

9. Ventura County Conditional Waiver & TMDL
Compliance ● ● ● ● ● ● ● LWA

10. Coordinated Monitoring Program for
Guadalupe River Watershed Mercury TMDL ● ● ● ● ● ● ● ● ● Tetra Tech

11. North Santa Monica Bay Coastal
Watersheds CIMP Implementation ● ● ● ● ● ● ● ● ● Tetra Tech

12. Central Coast Region Conditional Waiver
Cooperative Monitoring Program ● ● ● ● ● ● ● ● ● Tetra Tech

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1. CIMP Implementation and Reporting Services
Client Upper Santa Clara River, City of LA on behalf of multiple WMGs, Malibu Creek Watershed, and Upper San Gabriel River
Dates of Service 2015-Present
Relevance to RFP Demonstrates experience implementing CIMP monitoring requirements in a relevant watershed and providing value added services related to Permit compliance.

LWA has supported CIMP implementation and reporting for the USCR, ULAR, Ballona Creek, Dominguez Channel, Santa Monica Bay J2/3, Santa Monica Bay J7, Malibu Creek Watershed (MCW), and Upper San Gabriel River (USGR) WMGs. The following highlights eﬀorts provided for one or more clients:

Monitoring tasks have included:
• Prepared receiving water and outfall monitoring sites in advance of the upcoming wet weather events.

Coordinated and conducted monitoring during wet weather events by reviewing responsibilities with ﬁeld crews and discussing any modiﬁcations to the approach taken during previous events to incorporate lessons learned and characteristics of the storm. Communicated with municipal staﬀ regarding timing of sample collection and delivery during wet weather events. • Conducted non-stormwater (NSW) outfall screening. Outlined approach for conducting NSW source investigations and conducted source investigations for outfalls with signiﬁcant NSW discharges.

Developed technical memoranda detailing the results of the source investigations. • Developed QAPP and Health and Safety Plan for Field Activities for monitoring activities and related data quality assessments.
• Created a database that produces all the paperwork required for a monitoring event, including Chains of Custody (COCs), Field Logbooks, Bottle Labels, Bottle Order Report, and Site Report, reducing event preparation costs.
• Creating a user-friendly database that houses all water quality data and allows clients to run custom queries and export data into a California Environmental Data Exchange Network (CEDEN) compatible MS Excel ﬁle.
• Communicated with Regional Board staﬀ regarding implications of the 2018 Woolsey Fire.

Reporting tasks have included:
• Conducting data analysis to determine if water quality objectives and TMDL limits are exceeded using a custom-made tool. These analyses form the basis for the semi-annual and annual data deliverables. • Annual reporting related to monitoring includes summarizing monitoring completed in the year; conducting trends analysis; identifying QA/QC issues and corrective actions; presenting source investigation results; determining if TMDLs are attained; summarizing exceedances and assessing the impacts of MS4 discharges; and developing modiﬁcations to the CIMP . • Annual reporting related to program implementation include: summarizing stormwater and non- stormwater control measure implementation in the reporting year; calculating control measure capacity and comparing to the WMP goals; and summarizing proposed modiﬁcations to the WMP . • Completing a Report of Waste Discharge (ROWD), which included: a history of the stormwater programs; summarizing control measures; presenting potential future control measures; and compiling non-MS4 water quality data and conducting data analysis to determine if water quality priorities had changed.

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2. LA Region CIMP Development Services
Client USCR, ULAR, BC, USGR, RH/SGR, and ESGR WMGs and City of LA Dates of Service 2013-2016 and 2022-Present
Relevance to RFP NPDES Permit Requirements
LWA led the development of multiple CIMPs, which required monitoring in freshwater and saltwater environments, across water, sediment, and tissue matrices, and covered the range from standard pollutants to highly complex assessments of concentrations of historical pesticides and PCBs in storm-borne sediment.

Approaches developed by LWA for key components of the CIMPs were adopted countywide. LWA’s comprehensive understanding of the MS4 Permit, watershed-speciﬁc history and issues, and the goals of the Regional Water Board were critical in designing approaches tailored to each watershed that reduced the monitoring burden from the baseline MS4 Permit requirements. This included a tailored higher rainfall trigger for conducting stormwater monitoring in the USCR to minimize the likelihood of costly false starts.

Tetra Tech provides support to the City of Santa Clarita, the Los Angeles County Unincorporated Areas, and the Los Angeles County Flood Control District in implementing the approved CIMP for the Upper Santa Clara River watershed. In accordance with CIMP requirements, Tetra Tech conducts outfall and receiving water monitoring under dry and wet weather conditions and assesses compliance with water quality limits from TMDLs, the California Toxics Rule, the Basin Plan, and more. We prepare and submit post-event monitoring reports, Semi-Annual Reports, and Annual Reports in accordance with MS4 Permit requirements. We have also developed web-based databases to store, visualize, analyze, and share data. Tetra Tech previously conducted weekly sampling at select sites in accordance with the Bacteria TMDL and now conducts monthly sampling at the receiving water sites in accordance with CIMP requirements.

Tetra Tech leveraged a previously built water-quality database to reduce data management costs for the USCR WMG. Referred to as EnDAR, the custom database has the following features:
• A website using Azure single sign-on for secure client access to reports. Reports provide access to all data (chemistry, ﬁeld parameters, habitat, toxicology, and bacteria). Weather conditions during sampling (dry vs. wet) are associated with the chemistry results used for report ﬁltering. • A data manager for such tasks as planning sampling events and uploading Electronic Data Deliverables (EDDs) for reference, laboratory, and other data.
• A notiﬁcation system that emails users about system events such as data uploads, upload errors, and criteria exceedances.
• A SQL Server database for secure storage of all data. • Complete data traceability, including tracking of who uploaded data and when, maintaining a history of all changes, and archiving of all EDDs. Immediate, interactive feedback on upload status and error identiﬁcation is also provided.

Imports and exports of data in CEDEN formats, as these CIMP Groups are required to report all their data to the Water Board every six months according to EDD templates developed by CEDEN.

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3. Malibu Creek Watershed CIMP
Client Malibu Creek Watershed WMP Group
Dates of Service 2015-Present
Relevance to RFP Wet Weather Monitoring, NPDES Permit Requirements Since 2015, LWA has provided monitoring, reporting, data management, and regulator assistance to the MS4 National Pollutant Discharge Elimination System (NPDES) Permittees in the Malibu Creek Watershed: cities of Agoura Hills, Calabasas, Hidden Hills, and Westlake Village and the County of Los Angeles and Los Angeles County Flood Control District (Group).

Primarily, LWA has been overseeing the duties laid out in the CIMP for the Malibu Creek Watershed. The CIMP includes both wet and dry weather monitoring at 10 receiving water sites, wet weather monitoring at four outfall sites, and dry weather monitoring at three non-stormwater outfall sites. The CIMP also includes weekly bacteria monitoring and bimonthly trash monitoring.

Monitoring Tasks Included:
• Developing a QAPP and a Health and Safety Plan (HASP) to meet the requirements called out in the C I M P.
• Monitoring at 10 receiving water sites during three wet weather and two dry weather events annually for toxicity, bacteria, nutrients, metals, historical pesticides (including storm-borne sediment analysis), and general water quality parameters. • Oversight of subcontractor conducting weekly bacteria monitoring at 10 sites throughout the watershed and bimonthly trash monitoring that follows the Trash Monitoring and Reporting Program (TMRP) that is included within the CIMP .
• Conducting non-stormwater outfall screens, which included working with the County’s GIS layers to locate all the MS4 catch basins that drain to the outfall and map out a visitation route; visiting all the catch basins multiple times on varying schedules to determine the source of water at the MS4 outfalls. Screenings were scheduled for three times of day (early morning, midday, and afternoon).

Summary memoranda were developed detailing the process and ﬁndings. • Creating a Microsoft Access database that produces all the paperwork required for a monitoring event, including COCs, Field Logbooks, Bottle Labels, Bottle Order Report, and Site Report, which reduces event preparation time and costs.
• Creating a user-friendly MS Assess database that houses all the water quality data. The database allows the user to run custom queries and export them to a CEDEN-compatible MS Excel ﬁle. The database has exceedances ﬂagged.
• Contracted with an engineering company to design and construct autosampler sites that are used for collecting composites during wet weather events.
• Reporting Tasks Included:
• Conducting analysis on newly acquired data to determine if water quality objectives and TMDL limits are exceeded using a custom-made MS Excel tool. These analyses form the basis for both the 6- month and the annual data deliverables required by the MS4 Permit. • Annual reporting to meet MS4 Permit requirements related to monitoring includes: summarizing the monitoring completed in the reporting year; conducting dry and wet weather trends analysis to evaluate if conditions are improving, declining, or staying the same; identifying QA/QC issues and associated corrective actions; presenting source investigation results; conducting calculations to

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determine if TMDL mass based, seasonal average, annual average, and allowable exceedance day limits are attained; summarizing exceedances of relevant limits and assessing whether or not the MS4 Permittees caused or contributed to observed exceedances; and developing modiﬁcations to the CIMP .
• Annual reporting to meet MS4 Permit requirements related to program implementation includes:
summarizing stormwater and non-stormwater control measures implemented in the reporting year; calculating control measure capacity and comparing to the WMP goals; and summarizing proposed modiﬁcations to the WMP .
• Completing a ROWD, which included: providing a history of the stormwater programs implemented by the MS4 Permittees; summarizing control measures implemented during the current permit term; presenting potential future control measures; and compiling non-MS4 water quality data and conducting data analysis to determine if water quality priorities had changed since development of t h e W M P.

4. Calleguas Creek Watershed Monitoring and Special Studies Client Stakeholders Implementing TMDLs in the Calleguas Creek Watershed (CCW) Dates of Service 2006-Present
Relevance to RFP Wet Weather Monitoring, Reporting and Analysis, NPDES Permit Requirements LWA has provided regulatory and technical water-quality support to the CCW since 1998 and has assisted with watershed planning, monitoring, policy review, and management activities. LWA assisted stakeholders with the development of Third-Party TMDLs for nitrogen, salts, metals, toxicity, organochlorine pesticides, and PCBs and provided support for the Regional Board-developed TMDLs for trash and sediment. Since 2006, LWA has been coordinating the implementation of all TMDLs in the CCW. LWA is responsible for tracking and conducting special studies, monitoring, and reporting requirements under the TMDLs.

LWA developed and is currently implementing a multi-pollutant TMDL monitoring program in support of the CCW Stakeholders. The approach represented a ﬁrst-of-its-kind in Southern California, integrating multiple TMDL monitoring requirements into a single, cohesive program. LWA identiﬁed opportunities to consolidate eﬀorts and worked with the CCW stakeholders to gain Regional Board support for the integrated approach.

Monitoring is coordinated among MS4 permittees, wastewater plants, and irrigated agricultural operations.

LWA completed a QAPP to meet the requirements of all six TMDLs in the watershed. Analyses conducted under the QAPP and managed by LWA include: toxicity testing in water and sediment; current and historic pesticides; PCBs and metals in water, sediment, and tissue; nutrients and salts in water; various ﬁeld measurements; and estuary benthic invertebrate evaluations. Monitoring is conducted at freshwater receiving water sites, urban and agricultural land use sites, and Mugu Lagoon. To track and manage the complexities of this monitoring program, LWA developed a ﬁeld preparation database tool that cost- eﬀectively generates sample labels, ﬁeld logs, COCs, and checklists for each site. LWA produces an Annual Monitoring Report each year to document its monitoring eﬀorts and results.

In support of the CCW, LWA has led 13 special studies. Key special studies LWA has led or is in progress include Microbial Source Tracking, Sedimentation and Sediment Transport, Copper Water Eﬀect Ratio (WER) and Biotic Ligand Model (BLM) SSO/Basin Plan Amendments, Natural Attenuation Rates and Attainability of Organochlorine Pesticide Allocations, and USEPA selenium criteria implementation and TMDL update Studies.

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5. LA River Bacteria Source Investigation Study and Bacteria TMDL Development and Implementation Client City of Los Angeles Watershed Protection Division (WPD) and multiple cities Dates of Service 2006-Present
Relevance to RFP Dry Weather Monitoring – Monthly Bacteria TMDL Monitoring, Optional Special Studies
As part of the Cleaner Rivers through Eﬀective Stakeholder TMDLs (CREST) stakeholder process and to support the
development of the LA River Bacteria TMDL, WPD funded a Bacteria Source Investigation (BSI) Study of the LA River. The overall goal of the study was to quantify the relative loading rates of bacteria sources, particularly urban runoﬀ, and uncontrollable sources (e.g., birds or regrowth) along the most-impacted reaches of the LA River. The array of bacteria measurements was synthesized using a Weight-of-Evidence Approach and Monte Carlo analysis to highlight priority outfalls for TMDL implementation and to quantify the expected eﬀects of implementation actions. Subsequent to the BSI Study, LASAN funded the development of the LA River Bacteria TMDL through a stakeholder process. Team members authored TMDL sections for the source assessment, targets, linkage analysis, allocations, and a dry weather implementation strategy. Development of each of these sections was coordinated with the diverse CREST stakeholder group (MS4s, Heal the Bay, Caltrans, the Regional Water Board, and USEPA), including a variety of meetings and a lengthy series of presentations. The TMDL ultimately adopted by the Regional Board has a 25-year dry weather schedule, the longest dry weather schedule in the region. Paradigm and LWA have led the development of multiple Load Reduction Strategies (LRSs) for LASAN to help the City of Los Angeles comply with the LA River Bacteria TMDL. LWA served as a lead author for the LRS reports, coordinating meetings with other cities that are members of the LRS groups, and led several meetings with Regional Water Board staﬀ.

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6. Los Angeles Region Site-Speciﬁc Objective (SSO) Studies Client Multiple Los Angeles-Region Agencies
Dates of Service 1999-Present
Relevance to RFP Optional Special Studies
LWA developed and implemented SSO studies for multiple agencies within the LA Region, including the City of LA, City of Burbank, LA County Sanitation Districts, and stakeholders in the Calleguas Creek and LA River watersheds. The SSOs were focused on copper, lead, and ammonia and were the ﬁrst and only SSOs adopted by the Los Angeles Regional Water Board. LWA developed and implemented work plans to develop copper WERs in support of TMDL implementation in both the LA River and Calleguas Creek watersheds. The copper WER studies in the LA River watershed evolved through two phases. Phase I was conducted in support of three Water Reclamation Plants operated by the cities of LA and Burbank. Phase II focused on developing both copper and lead SSOs to support stormwater compliance with the LA River Metals TMDL. Both studies were conducted through a stakeholder process that included the Regional Water Board and USEPA staﬀ, multiple cities, and NGOs.

Additionally, LWA provided support to participating agencies, including those representing Disadvantaged Communities (DACs), in garnering support from elected oﬃcials and senior public works management. The Wasteload Allocations (WLAs) for permittees in the LA River Metals TMDL were increased as a result of the Phase I and II work. LWA supported MS4 Permittees during negotiations with the Regional Board to incorporate the results into the Basin Plan and the TMDL. LA River MS4 Permittees have not had a single exceedance of copper or lead in the study area since the amended TMDL was approved.

LWA recently completed preliminary work on zinc utilizing the WER and recalculation procedures. The preliminary work included analyzing watershed data, using previous studies and the zinc Biotic Ligand Model (BLM) to predict potential SSOs, and implementing a pilot study. The pilot study included collecting and analyzing WER samples, recalculating the criteria, and estimating the reduction in best management practice (BMP) costs based on potential SSOs.

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7. LA Countywide MS4 NPDES Permit Renewal Support
Client City of LA, LA County DPW, Ventura County Watershed Protection District Dates of Service 2010-2012 and 2019-Present
Relevance to RFP Wet Weather Monitoring, Reporting and Analysis, NPDES Permit Requirements During the development of the LA Regional MS4 Permit, LWA provided regulatory support to MS4 Permittees via contracts with the City of LA, the County, and Ventura County. LWA assisted these entities in developing comments on key issues in the Working Proposal (December 2019) and the Tentative Order (August 2020), including the incorporation of TMDLs into the Permit, monitoring requirements, BMP-based compliance mechanisms, and monitoring and reporting requirements. LWA has participated in meetings with Regional Board staﬀ and NGOs to protect several key elements of the current Permit, which were developed by LWA as part of the 2012 MS4 Permit and utilized by the Regional Board as the basis for key permit sections, including the watershed-based permit structure, CIMP ﬂexibility, and utilizing Watershed Management Plans/BMP-based compliance options. As part of the 2012 re-issuance process, LWA identiﬁed modiﬁcations to current programs, developed the suggested framework and content for the watershed programs, and provided justiﬁcation for modifying the previous permit structure to accommodate the proposed approach through modiﬁable minimum control measures and monitoring requirements.

8. On-Call Specialized and Expert Services for TMDLs and Regulatory Support Client City of LA and Los Angeles County Department of Public Works Dates of Service 2008-Present
Relevance to RFP Program Management, Reporting and Analysis, NPDES Permit Requirements LWA has supported the City of LA's eﬀorts to eﬀectively engage in TMDL development and subsequent amendments. During TMDL development, LWA reviewed, commented, and supported negotiations on the following TMDLs developed by the Regional Board and/or USEPA: Santa Monica Bay DDT and PCBs, Santa Monica Bay Marine Debris, LA River Metals, LA River Nitrogen Compounds, LA River Trash, Ballona Creek Metals, Ballona Creek Estuary Toxics, Ballona Creek Trash, Machado Lake Toxics, and LA Area Lakes TMDLs.

Subsequent to TMDL adoption, reopeners provide opportunities to improve the TMDLs based on new information. LWA and Paradigm supported the City of LA with analyses and comments for a number of metals and toxics TMDLs and multiple bacteria TMDL reopeners (Santa Monica Bay, Marina del Rey, Cabrillo Beach, and Ballona Creek bacteria TMDLs). A variety of alternative approaches were evaluated for 1) calculating geometric mean concentrations for determining compliance and 2) revising the allowable exceedance rate based on more recent “point zero” data. These analyses were conducted in close coordination with Regional Board staﬀ before the draft Basin Plan Amendments were released for public comment. Key outcomes included revised wet weather milestones for Santa Monica Bay, revised ﬁnal WLAs for Ballona Creek, removal of geomean compliance requirements until 2021, and replacement of intensive follow-up monitoring in Ballona Creek with a more reasonable and valuable outfall monitoring program.

LWA has provided specialized regulatory and technical services related to addressing a range of regulations with the potential to impact multiple MS4 Permittees, including, but not limited to:
• Developed comments on the 2018 Statewide Bacteria Recreational Water Quality Objectives.

Additionally, drafted comments during the Regional Board’s incorporation of the statewide objectives into the LA Basin Plan. Comments resulted in changes to the adopted objectives to ensure dischargers could utilize the ﬂexibility provided in the statewide objectives, including allowance for the application of the exceedance day approach for the geometric mean and seasonal suspensions.

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• Developed comments on the State Board’s 2019 Proposed Order related to the approval of E/WMPs submitted pursuant to the 2012 MS4 Permit. The comments primarily focused on supporting the approaches taken in the existing E/WMPs related to the Reasonable Assurance Analysis (RAA), source assessment, and compliance.
• Developed comments on the Regional Board’s 2020 Tentative Conditional Waiver for Non-Point Sources of Trash (Tentative Waiver). The primary focus was on ensuring consistency between requirements identiﬁed in the Tentative Waiver and those identiﬁed in the TMDLs.

9. Conditional Waiver & TMDL Compliance
Client Ventura County Farm Bureau, on behalf of the Ventura County Agricultural Irrigated Lands Group (VCAILG)
Dates of Service 2004-Present
Relevance to RFP Program Management, Dry Weather Monitoring, Wet Weather Monitoring, Reporting and Analysis, NPDES Permit Requirements
Since 2004, LWA has provided regulatory assistance to the Ventura County agricultural community through the local Farm Bureau for compliance with the Conditional Waiver of Waste Discharge Requirements for Discharges from Irrigated Lands (Conditional Ag Waiver). LWA assisted in negotiating the terms of all three Conditional Ag Waivers adopted by the Regional Board. Following the adoption of the ﬁrst Conditional Ag Waiver, LWA coordinated the formation of the discharger group (VCAILG) and developed a membership database, which is currently maintained for over 1,400 enrollees, over 3,200 parcels, and more than 81,000 irrigated acres. Upon adoption of each Conditional Ag Waiver, LWA compiled membership statistics and information regarding cultural practices to complete VCAILG’s Notices of Intent (NOI). Included in the NOI submittals to the Regional Board were the QAPP and Monitoring and Reporting Program (MRP) Plan. LWA developed the monitoring strategy to meet the requirements of the Conditional Ag Waiver, TMDLs, which were incorporated into the Waiver, and also coordinated with other applicable monitoring programs to leverage those eﬀorts and data. Additionally, LWA contributes to education meetings, informing farmers of their responsibilities for Conditional Ag Waiver compliance and summarizing water quality monitoring data.

Finally, LWA plans, executes, and reports on special studies required by the Conditional Ag Waiver.

Tasks Included:

In developing the QAPP and MRP Plan, LWA assisted with the selection of all monitoring sites within the 3 major Ventura County watersheds and conducted site assessments to verify relevance to the monitoring program and safe access. LWA has led the Conditional Ag Waiver monitoring eﬀort since its commencement in 2007, while speciﬁc requirements have changed over the iterations of the Conditional Ag Waiver; in general, this involved two wet weather and two dry weather events at up to 24 sites every year for toxicity, pesticides, nutrients, salts, copper, bacteria and general water chemistry parameters. LWA developed and maintains the monitoring database of all water, sediment, and ﬁsh tissue. Monitoring data is then compiled and presented in the VCAILG Annual Monitoring Report, produced by LWA. • LWA developed and maintains a database for enrollment, parcel, ownership, grower records, education credits and the results of farm management practice surveys regarding agricultural BMP implementation. Websites have been designed and used for farmers to enroll in VCAILG and complete the BMP survey. Plans are underway to utilize the website for outreach and education purposes speciﬁc to farm location and assist in implementation of the Water Quality Management Plan. • LWA is responsible for the development of Water Quality Management Plans (WQMPs) triggered by exceedances of water quality “benchmarks” and now required on a set schedule. Implementation of

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9. Conditional Waiver & TMDL Compliance
Client Ventura County Farm Bureau, on behalf of the Ventura County Agricultural Irrigated Lands Group (VCAILG)
Dates of Service 2004-Present
Relevance to RFP Program Management, Dry Weather Monitoring, Wet Weather Monitoring, Reporting and Analysis, NPDES Permit Requirements
the WQMP began in 2008; this process includes surveying growers to identify current BMP implementation and to provide outreach and guidance in areas that could be improved in order for agriculture to meet Conditional Waiver water quality benchmarks and TMDL load allocations. • Additionally, LWA is assisting the agricultural community with eﬀective TMDL compliance and the review and comment process during new TMDL development. At present there are seventeen TMDLs with load allocations incorporated in the Conditional Ag Waiver as benchmarks. • Separate from compliance monitoring, LWA wrote a Bacteria Special Study Work Plan to fulﬁll a requirement of the 2010 Conditional Ag Waiver. The purpose of this study was to assess the quality of agricultural discharges with respect to bacteria during wet and dry weather conditions. Samples for this study were collected from edge-of-ﬁeld runoﬀ, tile drain discharges, and in agricultural drainage ditches conveying communal discharge from multiple farm properties. The ﬁnal report for this eﬀort was submitted in 2016.

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3 Plan of Study/Scope of Work
The LWA Team’s ongoing support to the City and the USCR WMG with implementation of the USCR CIMP provides us with an exceptional understanding of the Watershed Management Area’s (WMA) unique setting, as well as its regulatory challenges associated with the MS4 Permit and regular changes to the Basin Plan, 303(d) list, and TMDLs. As regulations continue to evolve, the USCR WMG can continue to count on LWA Team to provide innovative approaches that are measurable, meaningful, and achievable for demonstrating compliance. LWA and Tetra Tech have worked alongside the City and other local and regional partners to navigate complex permitting and regulatory challenges for many years.

Our Team’s approach to USCR CIMP implementation will be consistent with past practice and will emphasize clear and regular communication; appropriate staffing of technical tasks; use of technical experts on topics with compliance implications; production of high-quality data and work products that require limited to no rework; responsiveness for wet weather monitoring; and leveraging existing data to make informed decision-making. Greater detail regarding the LWA Team’s approach to implementing the USCR CIMP is provided in the following sections.

3.1 Program Management
The overarching goal of the LWA Team project management approach is to implement an eﬃcient and eﬀective system for achieving project transparency, in particular: a shared understanding of the status of tasks, monitoring schedules, and reporting deliverables. To eﬀectively manage the project and communicate with the Group, the LWA Team will utilize a combination of a monitoring/reporting schedule as well as meetings and email updates to keep in touch. Clear expectations regarding frequency and lines of communication will be established during the ﬁrst monthly check-in call. LWA will work with the City to ensure the LWA Team meets the expectations of the CIMP Group, and work through issues of project implementation as they arise.

3.1.1 Monthly Reports
The LWA Team manager will submit monthly invoices and reports outlining the deliverables and work completed for that month. The invoice and monthly report will include itemized work efforts consistent with submitted costs, staff with rates and hours worked, and budget tracking by task. In addition, the Team will provide a central repository for all regulatory information, data, reviews, and analyses, and establish a SharePoint site for the City and the WMG.

3.1.2 Monthly Check-In Calls
To effectively manage the project and communicate with the CIMP Group, the LWA Team will utilize a combination of meetings and email updates to communicate the status of the project. The LWA Team will conduct monthly meetings during project implementation, including presentations to the WMG on the status of monitoring, data analysis, special studies, and the draft semi-annual and annual reports.

The LWA Team currently meets with the USCR WMG on the 3 rd Tuesday of each month. The Team
proposes this same schedule for monthly coordination meetings, which are critical to CIMP implementation. The Team will continue to distribute a meeting agenda in advance and follow each meeting with minutes. Each meeting will address the status of work products, sampling events, action items, WMP projects, project tracking, and other topics of interest to the WMG. Meetings will be conducted virtually to facilitate participation among WMG members for project efficiency. The Team will be available for in-person meetings as requested.

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3.1.3 Coordination with the County
The LWA Team will continue coordinating with the Los Angeles County Flood Control District (LACFCD) and the Los Angeles County Sanitation District (LACSD) prior to dry- and wet-weather events, as necessary. During wet-weather sampling events, the LACFCD performs sampling at the Santa Clara River mass emission station (CIMP site SNTCLR_6_ME), while the Team samples at all other CIMP sites. During dry weather sampling events, the LACFCD samples at SNTCLR_6_ME, the LACSD samples at the Reach 5 (SNTCLR_5_R-E) and Reach 7 (SNTCLR_7_R-A) sites, and Team member Tetra Tech samples at outfall sites.

Following all sampling events, the Team will correspond with the LACFCD and LACSD to obtain data. In addition, we will coordinate with the LACFCD to obtain access permits for the monitoring locations as needed.

3.1.4 Coordination with LACSD for Dry Weather Samples
The Team currently collaborates with the LACSD on the timing of the critical dry weather event in July and the second dry weather event (typically in January). Following sampling events, the Team will correspond with the LACSD to obtain data.

3.1.5 Tracking Changes with New NDPES Permit
The LWA Team has worked with the WMG to identify new program requirements during the last MS4 Permit renewal, such as adjustments to the Semi-Annual and Annual Report contents and lower reporting limits for monitoring constituents. The Team will continue to track any updates that come with the next MS4 Permit and will propose program adjustments as needed.

3.1.6 Permission Coordination with Five Points
The LWA Team will continue coordinating with Five Points to obtain access to the Reach 5 monitoring site (SNTCLR_5_R-E). To access SNTCLR_5_R-E, the LWA Team opens a combination lock on a gate and provides a text alert to Five Points about entering as well as leaving. The LWA Team will also coordinate with Five Points on the QAPP and liability insurance.

3.1.7 Conduct Water Quality Monitoring
The proposed LWA Team currently conducts Water Quality Monitoring for the CIMP program. Please see sections 3.2 through 3.4 below, for details on conducting program-related Water Quality Monitoring.

Program Management Outputs
Eﬀective program management by the LWA Team will ensure smooth implementation of the CIMP, with all requirements being met in an eﬃcient and timely manner. The Program Management outputs serve as an umbrella for subsequent tasks and provide a bridge for eﬃcient interfacing among the LWA Team, WMG, and LACSD. Speciﬁc deliverables/outputs include:
• Monthly invoices and progress report, which include a task breakdown summary, presented expended budget, remaining budget, an explanation of the work completed, and work percent complete.
• Meeting agendas, meeting summary notes, and action items. • LACFCD access permits.

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3.2 Dry Weather Monitoring
The MS4 Permit and USCR CIMP require two dry weather monitoring events per monitoring year. For the USCR WMA, the critical dry-weather event occurs in July, the historically driest month, and the second dry-weather event typically occurs in January. Dry weather events are performed at least 72 hours after a rain event of 0.1-inch or greater.

3.2.1 Dry Weather Monitoring at Outfalls
The LWA Team will perform dry weather monitoring for the two outfalls listed below and in Attachment 2 of the RFP. The outfalls were identified in the current CIMP and one outfall, PD 2507, was added to the dry weather outfall monitoring program after non-stormwater outfall screenings found that they had significant dry weather flow.
• PD 2507 (significant dry weather flow).
• Lake Elizabeth (East) outfall.

Monitoring of the outfalls will be conducted in accordance with the guidance in the CIMP and lessons learned during the past ten years of CIMP implementation.

3.2.2 Annual Monitoring for LACSD in January and July
The Team currently collaborates with the LACSD on the timing of the critical dry weather event in July and the second dry weather event (typically in January). Following the sampling events, the Team will correspond with the LACSD to obtain the data.

3.2.3 Coordinate with LACSD Monitoring
The LWA Team will coordinate with the LACSD on dry-weather monitoring dates to ensure watershed- wide consistency and efficiency. The LACSD samples the Reach 5 receiving water site (SNTCLR_5_R-E) and the Reach 7 receiving water site (SNTCLR_7_R-A). As a result of this interagency collaboration, dry- weather sampling is only needed at the outfalls listed in Subtask 3.2.1.

3.2.4 Mass Emission Site Coordination
The LWA Team will coordinate with the LACFCD on dates for dry weather monitoring to ensure watershed-wide consistency and efficiency. The LACFCD samples the Reach 6 receiving water site/Santa Clara River mass emission station (SNTCLR_6_ME). As a result of this interagency collaboration, dry weather sampling only needs to be conducted at the outfalls listed in Subtask 3.2.1 .

3.2.5 Land Use/Significant NSW Discharge Outfall Monitoring Please see Section 3.2.1 for a description of the non-stormwater outfall monitoring, which will be conducted by the LWA Team.

3.2.6 NPDES Permit List
Once a new MS4 Permit comes into effect, the WMG will be required to monitor the full list of constituents in Table E-6 of the Monitoring and Reporting Program of the MS4 Permit for the critical dry weather event of the first monitoring year under the new MS4 Permit. Any constituents that are either

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non-detect or do not have water quality objectives or have concentrations below applicable water quality objectives are not required to be monitored further. Since the critical dry weather event of the first monitoring year will require more constituents than the LACSD currently samples, the LWA Team will complete sampling at Reach 5 receiving water site (SNTCLR_5_R-E) and Reach 7 receiving water site (SNTCLR_7_R-A) for that event, if necessary.

Dry Weather Monitoring Outputs
• Dry weather samples and associated Chain-of-Custody.
• Complete and accurate field logs.

3.3 Dry Weather Monitoring – Monthly Bacteria TMDL Monitoring Pursuant to the CIMP, the LWA Team will perform monthly bacteria monitoring at select receiving water sites. Samples will only be analyzed for E. coli.

3.3.1 Receiving Water Monitoring Locations
The LWA Team will be monitoring three sites each month of the monitoring year: 1) Reach 5 receiving water site, SNTCLR_5_R-E; 2) Reach 6 receiving water site, SNTCLR_6_ME; and 3). Reach 7 monitoring site, SNTCLR_7_R-A, during dry weather conditions.

3.3.2 Monthly E. coli Bacteria Samples
Monitoring will be performed on the same day each week as much as possible for consistency in reporting. The Team will document weather conditions (e.g., dry) at the time of sample collection and all other observations and water quality measurements stipulated in the USCR CIMP. The collected samples will be analyzed for E. coli.

3.3.3 Sample for DNA and/or RNA
If desired by the WMG, the Team is prepared to collect additional samples for DNA and/or RNA testing to identify sources of elevated E. coli results. The LWA Team has conducted multiple microbial source tracking (MST) studies throughout Southern California and has been engaged in ongoing conversations with the City to conduct source investigations and DNA testing for MTD 1643 and PD 0717 following consistently elevated bacterial results. In 2019, DNA was analyzed for bird, horse, dog, human, and general fecal pollution sampling after weekly Bacteria TMDL sampling results showed consistently high results. In addition, the LWA Team is prepared to address the WMG’s concern regarding the potential presence of high HF183 concentrations in receiving water resulting from treated effluent from the LACSD water reclamation plants and has provided similar investigative support for other clients in the Los Angeles region.

Dry Weather Monitoring Outputs
• Monthly E. coli samples and associated Chain-of-Custody. • Complete and accurate ﬁeld logs.

3.4 Wet Weather Monitoring
The MS4 Permit and USCR CIMP require three wet-weather monitoring events per monitoring year, one of which should be conducted during the first-flush storm event of the season. At the onset of the wet

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weather season (October 1 to April 15), the LWA Team will hold an internal stormwater monitoring and sampling kick-off meeting, during which sampling personnel are trained and refreshed on the appropriate procedures and processes for monitoring in accordance with USEPA, Standard Methods, and CIMP requirements. The monitoring manager will coordinate with the City and the USCR WMG at the beginning of the storm season, and our Monitoring Lead will update the WMG of any potential events and provide updates.

3.4.1 Collect Samples at Two Receiving Water and Four Stormwater Outfall Monitoring Locations
The monitoring manager and/or monitoring lead will coordinate with the City prior to mobilization and notify the City and the WMG via email 24 hours prior to and upon activation of the sampling teams. The notification will include the following information:
• Anticipated start time and date of the storm event.
• Anticipated highest total amount of rain during any given 24-hour period during the storm. • Probability of precipitation.
• Confirmation that the laboratory has been notified to expect samples. • Any planned deviations from the established monitoring plan. • Name and cell phone number of the storm event coordinator.

The monitoring team will document dates and times associated with field mobilization and demobilization, and sample delivery to the laboratory. Following completion of the monitoring event, the monitoring manager or monitoring lead will email the WMG with a brief summary of the sampling event, including sites that were sampled, date sampled, and issues encountered, if any.

The monitoring team will collect and submit wet weather samples for analysis from the four outfall monitoring sites and two receiving water sites, as listed below:
• Reach 5
o SNTCLR_5_R-E
o Outfall
 PD 2443
• Reach 6
o SNTCLR_6_ME monitored by the LACFCD (i.e., will not be monitored by LWA Team) o Outfall
 PD 0717
• Reach 7
o SNTCLR_7_R-A
o Outfall
 PD 0494
• Lake Elizabeth (East) outfall
Monitoring will be conducted in accordance with the guidance in the CIMP and lessons learned during the past ten years of CIMP implementation.

The Team will collect samples and have them analyzed according to the list of constituents and frequencies presented in USCR CIMP (or any subsequent revisions after approval).

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After the Regional Board adopts a new MS4 Permit, the WMG may be required to monitor the full list of constituents in the current Table E-6 of the Monitoring and Reporting Program of the MS4 Permit for the first wet weather event of the first monitoring year. The LWA Team is prepared to conduct this monitoring, if required, and assist with the interpretation of the results in accordance with the USCR CIMP.

The monitoring frequency for E. coli at the Reach 5, Reach 6, and Reach 7 stormwater outfall sites will change to weekly in November 2028 to evaluate attainment of the geometric mean water quality-based effluent limitations (WQBELs).

3.4.2 Coordinate with County for Mass Emissions Site Monitoring and Rainfall Deployment
To ensure watershed-wide consistency and efficiency, the monitoring team will coordinate with the LACFCD when triggers indicate that wet weather monitoring should occur (see Subtask 3.4.3). The LACFCD samples the Reach 6 receiving water site/Santa Clara River mass emission station (SNTCLR_6_ME).

3.4.3 Evaluate Wet Weather Monitoring Mobilization Criteria Identified in CIMP
Once the wet weather season starts on
October 1st, the monitoring manager, with the
support of the monitoring lead, will be
responsible for monitoring the weather
conditions. Weather forecasting will be based
on the predictions of the National Oceanic and
Atmospheric Administration (NOAA) National
Weather Service for the following weather
stations:
• Bouquet Canyon @ Urbandale (Auto
Rain Gage Ref. ID AL390).
• Castaic Junction (Auto Rain Gage Ref. ID
1012B).
• Newhall – Soledad Canyon (Auto Rain Gage Ref. ID 32C).

Staff mobilization for the first significant storm event of the year will be triggered when forecasts for two of the three weather stations predict a 24-hour rainfall depth of at least 1 inch at a 70% probability the day before the start of the storm event. Further, mobilization will only be triggered if the predicted storm event is preceded by at least three days of dry conditions (less than 0.1 inch of rainfall each day). For subsequent storm events, wet weather monitoring will target those forecasted to produce sufficient rainfall and runoff to meet program objectives; the appropriate timing of staff mobilization will be coordinated with the City and the USCR WMG. Sampling mobilization triggers may be modified as needed with the approval of the City and the WMG. Because a significant storm event is based on predicted rainfall, it is recognized that monitoring may be triggered even if less than one inch of rainfall occurs. In this case, the monitoring event will still qualify as meeting this requirement provided that sufficient sample volume is collected to perform the required laboratory analyses. Documentation will be provided showing the predicted rainfall rate.

Local weather conditions will be monitored from the NOAA rain gages at Bouquet Canyon @ Urbandale, Castaic
Junction, and Newhall – Soledad Canyon.

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Wet Weather Monitoring Outputs
• Wet weather samples and associated Chain-of-Custody.
• Complete and accurate ﬁeld logs.

3.5 Source ID Additional Monitoring
The LWA Team will perform source identification and additional monitoring tasks pursuant to the MS4 Permit, CIMP, and WMG needs. We anticipate this task will largely consist of support to the City and the WMG for NSW outfall screening; significant NSW discharge source identification and associated outfall monitoring; and dry-weather outfall pollutant source investigations.

3.5.1 Exceedances Found in Dry Weather Flow
When dry weather exceedances of water quality objectives are observed, source identiﬁcation evaluations are performed. The LWA Team will develop a plan to investigate the source of ﬂow to the outfall in non- stormwater conditions. The speciﬁc outfall and contributing area will be assessed to develop an appropriate approach to determine if the observed ﬂow is permitted or requires abatement. Depending on the pollutant, air deposition, groundwater plume, or soil sampling may be pertinent in addition to or in place of upstream tracking. Depending on the location and planned activities, the LWA Team will coordinate with City or County staﬀ to obtain ﬁeld investigation approvals, traﬃc safety plans, and access permits.

The LWA Team is ready to implement source identiﬁcation if a signiﬁcant NSW discharge is identiﬁed in the future. The scale of the eﬀort can span from a simple desktop exercise to an extensive study. However, the eﬀort required to meet the Permit requirements is on the lower end of the spectrum. Prior to developing a source identiﬁcation approach, the LWA Team will outline options for the scope and scale of the process to ensure CIMP requirements are met, the desired information is collected, and the costs match the Group’s expectations. However, the most cost-eﬀective approach we have utilized to date is a visual assessment of the outfall and the surrounding drainage shed to identify ﬂows leading to the outfall and to catch basins. As the LWA Team has facilitated a similar process with other CIMP groups, we can provide insights into the pros and cons of approaches and support the Group’s selection of a preferred approach.

NSW outfall monitoring will consist of sampling at outfalls with signiﬁcant NSW discharges identiﬁed during the source identiﬁcation process as having sources attributed to illicit discharges, non-essential conditionally exempt discharges, or unknown sources. The outfalls will be monitored during regularly scheduled dry-weather receiving water events to support the evaluation of potential connections between discharge and receiving water quality and to maintain a cost-eﬀective approach. NSW outfall monitoring will be dynamic as monitoring will cease if the discharge is addressed or if it is demonstrated the discharge does not exceed any WQBELs or water quality standards for constituents on the 303(d) list.

3.5.2 Flow and Source Identification for Pollutant Abatement Where bacterial indicator exceedances are observed, the E. coli analysis will be supplemented with MST assays. On the authorization of the City, the LWA Team will initiate sampling with the reserved sample collected during the regular TMDL event. With MST testing, the relative impact of human versus non- human sources can be quantiﬁed, which is relevant to multiple aspects of TMDL implementation, including the following:
• Source identiﬁcation (i.e., determining whether sewage or non-sewage sources are responsible for elevated E. coli levels).

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• Source abatement (e.g., eliminating identiﬁed sewage sources and reducing the need for downstream structural BMPs).
• Basin Plan amendments (e.g., pursuing NSE provisions if non-human sources are predominantly responsible for exceedances).
• Risk assessment (e.g., prioritizing human sources for early implementation actions due to potentially increased human health risks).

The LWA Team has successfully led some of the most advanced MST studies in the LA region, including the Calleguas Creek Quantitative Microbial Source Tracking Study and the Los Angeles River Bacteria Source Identiﬁcation Study. LWA is also currently leading eﬀorts in San Diego County to use the results of a QMRA study in the San Diego region to inform implementation and ensure compliance with interim TMDL requirements. The San Diego study is the ﬁrst in the nation to attempt to develop SSOs for bacteria using MST and pathogen testing. However, adopting new criteria, such as SSOs, is fraught with regulatory and technical issues. Avoiding these issues through alternative approaches to demonstrating compliance potentially provides a more viable solution. LWA has also been engaged in developing an MST special study in the Newport Bay watershed to comply with a Bacteria TMDL Time Schedule Order (TSO). In Northern California, LWA is leading a multi-year study to identify sources of bacteria in the Lower American River for a group of stakeholders that includes the Central Valley Regional Water Quality Control Board and Sacramento stormwater permittees.

3.5.3 Source ID Additional Monitoring Frequency
Should routine dry-weather outfall monitoring indicate that the USCR WMG is causing or contributing to exceedances of receiving water limitations (RWLs), the Team will assist the WMG with dry-weather pollutant source investigations. These investigations will begin with a coordination meeting with the WMG and, if applicable, other stakeholders. Upon agreeing on the scope of the investigation, the LWA Team will perform systematic tracing of pollutants within targeted outfall catchments/drainage areas. The Team has partnered with a range of labs to facilitate source tracking, including analysis of human biomarker samples (e.g., HF183).

The LWA Team has assumed that one dry-weather pollutant source investigation will be conducted per monitoring year, for a total of three investigations over the course of this contract. The costing for this Subtask assumes each investigation will span two days, with two staff per day, and that approximately 20 samples each of HF183 and E. coli will be collected from the outfall and its manholes for investigation and analysis. The cost also includes LACFCD access permits and traffic control.

3.5.4 Field Operation Coordination
The LWA Team will coordinate with the WMG to obtain access permits from the County, LACFCD, and other agencies to perform monitoring-related activities. The LWA Project Manager and Task Leads will maintain regular communication to eﬀectively prepare for monitoring events, closely follow the progress of laboratory analyses, and track storms when needed. Updates will be provided during the monthly check-in calls to summarize completed and ongoing activities. Monitoring Coordination typically includes:
• Coordination with the LACFCD for sample schedule, storm tracking, coordination of deployment times, and collaborating post-event to collect data.
• Coordination with LACSD for dry weather in January and July, where sampling occurs as indicated by the LACSD receiving water monitoring schedule. The County collects mass emission site samples,

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and the LWA Team will collect other receiving water samples and an outfall sample if ﬂow is observed from the outfall and observed to be connected to the receiving water. • Coordination with Five Points for access permission to the Reach 5 monitoring locations. The LWA Team currently coordinates with Five Points for monitoring access permissions to this site.

3.5.5 Non-Stormwater Outfall Screening
Non-stormwater outfall screening and source identification are intended to identify and abate sources of persistent, significant dry-weather discharges and associated pollutants. NSW outfall screening was performed under the 2012 Los Angeles County MS4 Permit and may be required under a new Los Angeles Regional MS4 Permit (when adopted). The LWA Team will conduct NSW outfall screening at major outfalls, as defined by the USCR WMG’s outfall inventory. The LWA Team will coordinate with the City and LACFCD staff prior to conducting any screening events to ensure appropriate access permits and traffic control have been obtained. All outfall screenings will be performed during dry weather, at least 72 hours after a rain event of 0.1-inch or greater.

One initial outfall screening event will be performed to assess whether any outfalls are potentially contributing significant NSW discharges. Field technicians will record the following information:
• Date, time, weather.
• Photos of outfall and receiving water using a GPS-enabled camera. • Coordinates of outfall.
• Physical descriptions of outfall, site condition, and accessibility. • Discharge characteristics, such as odor and color.
• Presence of flow greater than trickle or no flow.
• Receiving water characteristics.

The LWA Team will conclude ‘no further assessment’ is needed due to one or more of the following findings:
• No flow is observed from the outfall.
• The source is confirmed to be from NPDES permitted, categorically exempt essential flow or natural flow.
• Flow is categorized as not significant.

For all outfalls with potentially significant NSW discharges, a second and third screening event may be conducted to validate findings during the initial screening event. During the second and third outfall screening events, field technicians will record the following information:
• Date and time of last visual observation or inspection. • Outfall alpha-numeric identifier.
• Description of outfall structure, including size (e.g., diameter and shape). • Description of receiving water at the point of discharge (e.g., natural, soft-bottom with armored sides, trapezoidal, concrete channel).

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• Latitude and longitude coordinates.
• Nearest street address.
• Parking, access, and safety considerations.
• Photographs of outfall condition.
• Photographs of significant NSW discharge or indicators of discharge, unless safety considerations preclude obtaining photographs.
• Estimation of discharge rate.
• All diversions, either upstream or downstream of the outfall. • Observations regarding discharge characteristics such as odor, color, presence of debris, floatables, or characteristics that could aid in pollutant source identification. • Water flow conditions in the receiving water at the point of discharge (dry, ponding, or flowing).

The field team will take photographs of each outfall and the receiving water with a GPS-enabled camera.

The USCR WMG will be notified as soon as practical if any potentially illicit discharge, as defined in the MS4 Permit, is observed during the field screening activities.

After completing each screening, the LWA Team will prepare and submit progress reports, all field logs, and photo-documentation within 30 days of each event. The photographs will be submitted in an electronic format and will show, at a minimum, outfall condition, NSW discharge, and upstream and downstream receiving water conditions.

The LWA Team has assumed that 60 outfalls will be screened, the same number as in the initial screenings. After the three screening events, three outfalls are assumed to exhibit significant NSW discharge and will need to be further investigated.

Source ID Additional Tracking Outputs
• Draft and ﬁnal NSW outfall screening work plan.
• NSW outfall screening summary memo with prioritized list of signiﬁcant NSW outfalls. • Draft and ﬁnal NSW discharge source investigation work plans. • Brief technical memorandums summarizing the results of NSW discharge investigations. • Draft and ﬁnal Dry Weather Pollutant Source Investigation work plan. • Brief technical memorandums summarizing the results of Dry Weather Pollutant Source Investigations.

3.6 Reporting
Each monitoring year, the LWA Team will prepare five post-event monitoring reports upon completing routine CIMP monitoring, 12 monthly bacteria TMDL reports, two semi-annual reports, and one annual report. The LWA Team will validate and evaluate all field and laboratory data, upload it to the CIMP database, perform QA/QC checks on the data, and prepare exceedance analysis reports.

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3.6.1 Coordinate with CIMP Group
The LWA Team will lead the development of information used to convey the status of the USCR area to the CIMP Group and the Regional Board. We will coordinate as appropriate with the CIMP Group to create and complement the writing, revision, and submittal of work products. Additionally, the LWA Team will lead the preparation of data for the bacteria TMDL, NPDES Permit, source identiﬁcation, or data collected as part of an enforcement action. The LWA Team will coordinate with the LACFCD to receive the MES monitoring data (after quality assurance checks have passed) and with LACSD to receive the receiving water monitoring data for the event.

3.6.2 Reporting of Water Quality Data
The LWA Team will prepare reports following each field event and summarize results semi-annually, as described below.

3.6.2.1. Technical Memos After Each Monitoring Event
The LWA Team will continue to prepare and submit post-monitoring event technical memorandums to the USCR WMG for each CIMP monitoring event, with a total of five post-monitoring event technical memorandums per monitoring year. Following receipt of laboratory data and data from the LACFCD and LACSD (as needed) for a monitoring event, the Team will create a post-event monitoring report that includes a description of the monitoring event (including which sites experienced flow/discharge), field measurement results for each site, analytical laboratory results for each site, discussion of water quality objectives compliance, summary and analysis of toxicity testing (if applicable to the event), and summary of QA/QC data. Completed field logs, site photographs, and analytical laboratory reports are also included. A draft of the post-monitoring event technical memorandum will be submitted for WMG review, and after receiving any comments or edits, a final post-monitoring event technical memorandum will be provided to the USCR WMG.

Additionally, the LWA Team will prepare a monthly Bacteria TMDL Status Report that summarizes single- sample results for the three sites noted in Task 3 above. The report will reference the Santa Clara River Bacterial TMDL for pertinent water-quality objectives and Waste-Load Allocations. Results that exceed either the single-sample or geometric-mean water quality objectives will be highlighted. The report will also clearly summarize the number of days during which exceedances were observed relative to the number of allowable exceedance days identified in the MS4 Permit.

3.6.2.2. Annual Report
LWA will continue to lead the water quality and watershed analysis chapters of the Annual Report. The LWA Team will leverage our detailed understanding of TMDLs and the Basin Plan to appropriately highlight exceedances of WQBELs, RWLs, and/or aquatic toxicity thresholds. In addition to highlighting exceedances, the Annual Monitoring Report (AMR) will provide an opportunity to understand the full breadth of monitoring results. The LWA Team will present key aspects of the Draft Annual Report during the monthly USCR WMG meetings and will make any revisions based on comments from the USCR WMG, with suﬃcient time to obtain necessary signatures and submit the complete Annual Report package to the Regional Board by December 15
th each year.

3.6.2.3. Semi-Annual Report
As required by the MS4 Permit and outlined in the CIMP , reporting requirements include semi-annual electronic data submittals in mid-June and mid-December (submitted with the Annual Report). LWA has

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developed an exceedance analysis tool to support reporting. The QA/QC’d data are uploaded to the tool, which contains all applicable limitations (including RWLs and TMDL targets), summed values are calculated where needed (e.g., total PCBs) and the exceedances are identiﬁed. Subsequently, LWA senior staﬀ review the exceedance analysis to ensure the analysis results are entirely accurate. Complete drafts of the dataset will be provided in advance per the approved schedule and revised based on comments. In addition, the WMP Progress Report Forms are required to be submitted on a semi-annual basis. The LWA Team will evaluate the attainment of WMP milestones and compile programmatic and project implementation information associated with the semi-annual reporting period to meet the WMP Progress Report Form requirements in the MS4 Permit.

3.6.2.4. TMDL Compliance
TMDL compliance tracking will be ongoing and summarized as part of the reporting process. Please see Section 3.6.2.1 for a description of TMDL compliance tracking for the monitoring events.

3.6.2.5 Exceedances of Water Quality Standards
LWA has developed an exceedance analysis tool to support reporting. The QA/QC’d data are uploaded to the tool, which contains all applicable limitations (including RWLs and TMDL targets), summed values are calculated where needed (e.g., total PCBs), and the exceedances are identiﬁed. Subsequently, LWA senior staﬀ review the exceedance analysis to ensure the analysis results are entirely accurate.

3.6.2.6 Entering Water Quality Data into CEDEN
The data will be compiled in a format comparable to the requirements of the CEDEN database and uploaded to CEDEN if required by the new MS4 Permit or as requested by the USCR WMG.

3.6.2.7 Conduct Data Analysis and Lab Data Comparison
To aid with reporting and analysis, the LWA
Team will continue to use its custom-built
Environmental Data Acquisition and Reporting
(EnDAR) system to store and report CIMP data.

EnDAR currently houses all water-quality data
relevant to the USCR WMG, including CIMP
monitoring results, toxicity data, and monthly
TMDL monitoring data for bacteria. Key features
of EnDAR include:
• A dedicated website using Microsoft
Azure single sign-on technology for simple
and secure access to the system, with the
ability to deﬁne permissions (e.g., view
only, view and edit) by user.
• A Microsoft Power BI “dashboard” that
allows users to visualize data through
interaction with a map of site locations,
time series graphs, bar graphs, data
tables, summary statistics, exceedances, and other reporting metrics. Dashboard elements can be exported for use in reports or in other software for further analysis. Currently, EnDAR has four Customized EnDAR system stores, exports, and displays
all USCR CIMP chemistry, field, microbiological, and
toxicity data in tabular and geospatial formats.

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dashboards: (1) ﬁeld measurements and general chemistry data, including summary statistics and time series plots; (2) toxicity data; (3) single-sample water quality objective summary for the Santa Clara River Bacteria TMDL; and (4) geometric mean water quality objective summary for the Santa Clara River Bacteria TMDL. These dashboards could be used to explore outfall and receiving water trends, investigate pollutant sources, and complete reporting associated with the MS4 Permit and relevant TMDLs.
• Customizable data reports to provide access to all data types-chemistry, ﬁeld parameters, habitat, toxicity, and bacteria. Weather conditions during sampling (i.e., dry or wet) are associated with all results for relevant report ﬁltering. Reports can provide more in-depth data views and querying than are practical for dashboards, and the output may be exported to Excel or PDF. • Allows authorized users to browse reference data tables and add/edit data. • EnDAR is hosted in cloud infrastructure for secure storage of all data. EnDAR also includes features for streamlining the sample collection process, which will be used by the LWA Team for sampling events, including:
 A data manager for such tasks as planning sampling events and uploading EDDs, including import and export of data according to CEDEN format.
 A notiﬁcation system that emails users about system events such as data uploads, upload errors, and exceedances.
• Complete data traceability, including tracking of who uploaded data and when, maintaining a history of all changes, and archiving of all EDDs.
• Immediate, interactive feedback on the status of uploads and identiﬁcation of errors. • A mobile data collection application with cloud-based storage of data that allows tracking of sample collection, entering weather and ﬁeld parameter data, and taking site photos during sampling. Using this mobile data collection application improves data quality and reduces costs associated with transcribing ﬁeld data from ﬁeld forms to EDDs. The application runs on both iOS and Android devices and is easily customized.
• Customizable chain-of-custody format tailored to each laboratory.

The LWA Team will maintain its stringent QA/QC system, in accordance with CIMP-defined data quality objectives, when reviewing all field and laboratory data. Data is not uploaded into EnDAR until QA/QC validation and evaluation are complete. The LWA Team will maintain copies and provide the USCR WMG with all field logs and photo documentation in accordance with the requirements of the MS4 Permit and the approved CIMP.

Reporting Outputs
• Draft and Final Post-Event Monitoring Reports.
• Monthly Bacteria TMDL Status Reports.
• Draft and Final Semi-Annual Reports.
• Draft and Final Annual Reports.
• Database of all CIMP information.

3.7 QAPP , Health and Safety Plan
The LWA Team will prepare updates to the QAPP and the HASP, as necessary.

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3.7.1 Quality Assurance Project Plan Development
The LWA Team will update the USCR CIMP’s current QAPP to address any new requirements in the anticipated revised MS4 Permit. The Team will ensure the QAPP thoroughly covers:
• Sampling locations and frequency.
• Sample handling and storage procedures.
• Laboratories that will be used for the monitoring program. • Analytical methods.
• Data processing procedures.
• Speciﬁc data quality objectives and data quality reporting. • QA/QC.

As part of the QAPP development process, the LWA Team will review and as needed, update the HASP.

The Team always prioritizes health and safety when performing field work. All field personnel will comply with the California Occupational Health & Safety (Cal-OSHA) requirements and any other Federal Occupational Health and Safety Administration requirements. The LWA Team will implement a HASP that includes information on potential chemical, physical, and biological job hazards associated with the proposed field activities; field monitoring equipment; personal protective equipment (PPE); work zone delineation and decontamination; emergency plan and hospital direction; and medical surveillance. The HASP will also address site-specific safety concerns at all sites, such as vandalism, site accessibility, lane closures, storm drain laterals, and other environmental hazards.

The HASP will also include additional safety precautions for conducting fieldwork during poor air quality resulting from seasonal wildfires. Our teams have been implementing these practices for ten years and are adept at taking additional precautions and truly prioritizing health and safety.

Before the initial start of field activities, the HASP will be reviewed by all field personnel. A tailgate safety meeting will be conducted for each field crew at the beginning of each workday; a Tailgate Safety Meeting log will be used to record all safety issues that are discussed by the Site Safety Officer with personnel prior to starting work.

3.7.2 Quality Assurance Project Plan Review of Laboratory Analysis The LWA Team will collect, validate, and manage all data produced by the analytical laboratories. If a component of the analysis does not meet the CIMP requirements, the LWA Team will work with the laboratory to correct the issue. If the correction is inadequate, the LWA Team will identify an alternative laboratory, inform the USCR WMG, and based on input, transition to a different laboratory. On large projects such as these, issues will come up. Having a robust QA/QC process in place allows for quick identification and correction of the problem, and if necessary, replacement of the laboratory. The labs included on the LWA Team were selected, in part, because of their data quality and their responsiveness to identified issues.

3.7.3 Quagga Mussel Spread Prevention Plan
Either in the HASP or in a separate Hazard Analysis and Critical Control Points (HACCP) planning document, the LWA Team will detail the measures to prevent the spread of Quagga mussels. Quagga mussels are an invasive species present in and near the USCR WMA. Field personnel can further spread it if proper precautions are not taken before, during, and after a sampling event. After sampling each site,

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field personnel will ensure that equipment and PPE (i.e., field boots, waders, etc.) are thoroughly decontaminated and scrubbed with a stiff-bristle brush to prevent potential spread between sites. At the completion of a sampling event, field personnel will decontaminate and scrub gear and equipment again with a stiff-bristled brush and allow the equipment to dry thoroughly to ensure any organisms are desiccated.

QAPP , Health and Safety Plan Outputs
• Revised QAPP.
• Revised HASP.
• Quagga Mussel Spread Prevention Plan.

3.8 Laboratory Review and Analysis
The LWA Team has selected certified laboratories capable of performing water quality analyses that meet the minimum levels identified in the USCR CIMP and the MS4 Permit. The LWA Team will coordinate with the laboratories to collect, validate, and manage all data produced by the certified laboratories prior to reporting activities.

3.8.1 Costs Related to First-Year Testing
Table E-6 of the MS4 Permit Monitoring and Reporting Program indicates that MS4 Permit screening is historically performed at the Reach 6 receiving water site, the mass emission station (MES). This MES is always monitored by LACFCD. The LWA Team does not expect to need to sample the Table E-6 parameters under a new MS4 Permit, as that sampling is conducted at the MES by LACFCD. Should it be necessary, the LWA Team will support the LACFCD with pre-event coordination and planning.

3.8.2 Identify Labs
The labs used for the routine CIMP monitoring would be State Water Resource Control Board ELAP- certified labs that are able to meet the project reporting limits as stated in the CIMP. The labs we have selected for testing to be consistent with the NPDES Permit and a potential new NPDES Permit are:
• Euroﬁns Environment Testing – General Chemistry.
• Enthalpy Analytical – General Chemistry and Permit Table E-6 Screening (if needed). • Pat-Chem Laboratories – Bacteria Testing.
• LuminUltra – DNA/RNA Testing.
• Nautilus Environmental – Toxicity Testing.

3.8.3 Coordination with Other Backup Labs
The LWA Team has identified a group of labs with redundant capabilities to allow for contingency reassignment of analysis in the event that any of the labs cannot meet CIMP reporting limits. In addition, the Team has identified additional labs with similar capabilities that can be contracted and assigned to analysis tasks on short notice. The Team will validate all field and laboratory data according to the data quality objectives described in the CIMP. If there are persistent quality control issues, we will coordinate on shifting analyses from one lab to another, given that there is sufficient redundancy among the labs selected.

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3.8.4 DNA/RNA Test Lab
The DNA/RNA specialty lab selected for this program is LuminUltra. The Team has been working with this lab since 2018 across Orange, Los Angeles, and San Diego Counties.

Laboratory Outputs
• Test laboratory certiﬁcate of qualiﬁcations to meet the approved/modiﬁed laboratory detection and reporting limits identiﬁed in the USCR CIMP.
• Laboratory analytical reports.
• EDDs.

3.9 Toxicity
The LACFCD currently performs toxicity monitoring at the Reach 6 receiving water site (SNTCLR_6_ME), but not at the other two receiving water sites (SNTCLR_5_R-E and SNTCLR_7_R-A).

3.9.1 Toxicity Monitoring Consistent with Attachment E and Attachment G of the Permit
Attachment G of the MS4 Permit provides clarification regarding triggers for additional toxicity monitoring at upstream receiving water. For example, if toxicity is present at SNTCLR_6_ME, as determined by a failed Test of Significant Toxicity (TST) t-test, but not above the toxicity identification evaluation (TIE) trigger, then toxicity sampling will be included at the upstream receiving water site(s) during the next monitoring event of the same weather condition (wet or dry weather) for which toxicity was determined to be present at SNTCLR_6_ME. Monitoring for toxicity during the subsequent upstream receiving water site(s) will occur at least 45 days following the date of sample collection, which led to a failed TST t-test.

Toxicity monitoring at upstream receiving water sites will continue until (1) the deactivation criterion (i.e., two consecutive samples that pass the TST t-test during the same weather condition) is met at SNTCLR_6_ME, or (2) a TIE is triggered and conclusively identifies the constituent or class of constituents causing toxicity.

The Team assumes two toxicity analyses may be needed at SNTCLR_7_R-A per year in the event that SNTCLR_6_ME fails a toxicity test. A cost is not included for a TIE because one has never been triggered. If a TIE is triggered based on the results of SNTCLR_6_ME, the Team will evaluate ways to accommodate additional costs, which may include needing to use contingency funds, given that the cost of conducting TIEs is significant (i.e., greater than $10,000 each).

3.9.2 Outfall Aquatic Toxicity Monitoring
Attachment G of the MS4 Permit provides clarification regarding triggers for additional toxicity monitoring at upstream outfall locations (i.e., (1) outfall sites located between the receiving water site and the nearest upstream receiving water site located on the same waterbody and (2) outfall sites located on tributaries that have a confluence with the waterbody where the confluence is located between the receiving water site and the nearest upstream receiving water site located on the same waterbody). For example, if toxicity is present at SNTCLR_6_ME, as determined by a failed Test of Significant Toxicity (TST) t-test, and above the toxicity identification evaluation (TIE) trigger, then toxicity sampling will be included at the upstream outfall site(s) during the next monitoring event of the same weather condition (wet or dry weather) for which toxicity was determined to be present at SNTCLR_6_ME if the TIE results do not

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conclusively identified the constituent or class of constituents causing toxicity. Monitoring for toxicity during the subsequent upstream outfall site(s) will occur at least 45 days following the date of sample collection, which led to a failed TST t-test. Toxicity monitoring at upstream outfall sites will continue until (1) the deactivation criterion (i.e., two consecutive samples that pass the TST t-test during the same weather condition) is met at SNTCLR_6_ME, or (2) a TIE conducted at the downstream receiving water site conclusively identifies the constituent or class of constituents causing toxicity, or (3) the discharge is eliminated.

3.9.3 Toxicity Species Testing Requirements
The LWA Team conﬁrms that dry-weather toxicity monitoring will be conducted using Chironomus dilutus, and wet-weather toxicity monitoring will be conducted using Hyalella azteca.

3.9.4 Coordination with County
Following dry and wet weather monitoring events, the LWA Team will coordinate with the LACFCD to receive their toxicity data and determine if additional toxicity monitoring is required at upstream receiving water or outfall sites.

Toxicity Outputs
• Toxicity reports produced by a qualified laboratory
• CEDEN formatted EDDs with bioassay data

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4 Schedule
Table 2 presents the schedule for the proposed tasks based on the RFP , required deliverables, and regulatory deadlines. Adjustments can be made as requested by the City. The LWA Team currently meets with the USCR WMG on the 3rd Tuesday of each month. The Team proposes this same schedule for monthly coordination meetings, which are critical to CIMP implementation. Staﬃng hours are provided in the Cost Attachment, and roles are described in Section 6.

Table 2. Proposed Schedule for USCR CIMP Implementation Task & Description Work Period Completion/Key
Dates

3.1 Program Management

3.1.1 Monthly reports
Invoice and
backup sent
mid-month and
capturing work
related to the
prior calendar
month.

Monthly; Mid-
Month

3.1.2 Monthly check-in calls Ongoing Monthly

3.1.3. Coordination with County Ongoing Monthly

3.1.4. Coordination with Los Angeles County Sanitation District for dry weather samples Ongoing Monthly

3.1.5 Monitoring regulatory requirement changes for newly adopted NPDES Permit
Current MS4
Permit expires in
September
2026.

Automatically
extended.

Working
Proposal/Draft
Tentative Order
for new MS4
Permit
anticipated in
2027-2028
To Be
Determined

3.1.6. Permission coordination with Five Point Ongoing Monthly

3.1.7 Conduct water quality monitoring as required by CIMP Ongoing Monthly

3.2 Dry Weather Monitoring

3.2.1. Dry weather monitoring at Outfalls Ongoing January and July, annually

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Task & Description Work Period Completion/Key
Dates

3.2.2 Single Instance during January and July each year (3 years) Ongoing January and July, annually

3.2.3 Coordinate with the Los Angeles County Sanitation District monitoring Ongoing January and
July, annually

3.2.4 Coordinate on Mass Emission Site with Los Angeles County for monitoring Ongoing January and
July, annually

3.2.5 Typically, the two dry weather sample events only include the land use outfalls and the significant non-stormwater flow outfalls and not the receiving water locations
Ongoing
January and
July, annually

3.2.6 First dry weather samples at all sites (TBD)
Not currently
required. Will be
conducted as
necessary based
on requirements
of the new MS4
Permit
To Be
Determined

3.3 Dry Weather Monitoring – Monthly Bacteria TMDL
Monitoring

3.3.1 Conduct dry weather monitoring at receiving water monitoring locations Ongoing Monthly

3.3.2 Monthly E. coli bacteria samples for TMDL 30-day
geometric mean monitoring Ongoing Monthly

3.3.3 Sample for DNA and/or RNA
Ongoing
(Sufficient
volume to be
continued to be
collected.

Potential benefit
of DNA/RNA
analysis to be
evaluated on a
case-by-case
basis.)
Monthly

3.4. Wet Weather Monitoring

3.4.1 Samples taken at two receiving water locations and four outfall monitoring locations
Wet Season
(October-April)
Annually
Three storms
annually

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Task & Description Work Period Completion/Key
Dates

3.4.2 Coordinate with County for Mass Emissions Site
monitoring, rainfall deployment, and post event data sharing and analysis
Ongoing
As needed
based on
weather
forecast and
data availability

3.4.3 Evaluate wet weather monitoring mobilization criteria identified in CIMP
Wet Season
(October-April)
Annually
As needed
based on
weather
forecast

3.5. Source Identification Additional Monitoring

3.5.1. Required when exceedances found in dry weather flow to determine potential sources of flow Ongoing As needed

3.5.2. Goal is to identify as permitted or to identify and quantify the source of flow and pollutant so that monitoring can cease and pollutant is abated
Ongoing As needed

3.5.3. Occurs during dry weather monitoring Ongoing As needed

3.5.4. Coordination with City or County staff for field operations Ongoing As needed

3.5.5. Non-stormwater outfall screening
Not currently
required. Will be
conducted as
necessary based
on requirements
of the new MS4
Permit
To Be
Determined

3.6. Reporting

3.6.2.1. Technical memos after each monitoring event Ongoing Submittal for
each monitoring
event
dependent on
timing of event
and obtaining
all necessary
data

3.6.2.2. Annual Report support for NPDES Permit – water quality and watershed analysis sections
July-December,
annually
December 15th,
annually

3.6.2.3. Semi Annual Report support for NPDES Permit – water quality and watershed analysis
Ongoing review
and compilation
of data as
received
June 15th and
December 15th,
annually

3.6.2.4. TMDL compliance tracking of data, broken down
monthly by wet and dry weather Ongoing Monthly

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Task & Description Work Period Completion/Key
Dates

3.6.2.5. Exceedances of water quality standards Ongoing Submittal for
each monitoring
event
dependent on
timing of event
and obtaining
all necessary
data

3.6.2.6. Potential additional need of entering water quality data into CEDEN if required
Not currently
required. Will be
conducted as
necessary based
on requirements
of the new MS4
Permit
To Be
Determined

3.6.2.7. Conduct data analysis and compare the lab data with the applicable water quality standards. Ongoing
Submittal for
each monitoring
event
dependent on
timing of event
and obtaining
all necessary
data

3.7 QAPP, Health and Safety Plan Required

3.7.1. QAPP consistent with NPDES Permit and any adjustments to comply with a new NPDES Permit and standard practices As part of CIMP
update based on
requirements of
the new MS4
Permit
To Be
Determined

3.7.2. QAPP review of laboratory analysis to determine efficacy of testing methods and results. Ongoing
Dependent on
timing of event
and obtaining
all necessary
data

3.7.3. Quagga mussel spread prevention Ongoing Monthly

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Task & Description Work Period Completion/Key
Dates

3.8 Laboratory Analysis

3.8.1. Costs related to a first-round testing from the large list of pollutants to be monitored, currently anticipated to be similar or consistent with Attachment E of the NPDES Permit
Not currently
required. Will be
conducted as
necessary based
on requirements
of the new MS4
Permit
To Be
Determined

3.8.2. Identify any and all laboratories to be used for testing that would be consistent with NPDES Permit and a new NPDES Permit, if applicable
Completed N/A

3.8.3. Coordination with other backup labs if quality control starts to wane Ongoing As needed

3.8.4. DNA/RNA test lab
Ongoing
(Potential
benefit of

DNA/RNA
analysis to be
evaluated on a
case-by-case
basis.)
Monthly

3.9 Toxicity

3.9.1. Toxicity monitoring Ongoing As needed

3.9.2. Outfall aquatic toxicity monitoring may be required Ongoing As needed

3.9.3. Dry weather toxicity monitoring will be conducted using Chironomus dilutus and wet weather toxicity monitoring will be conducted using Hyalella azteca
Ongoing As needed

3.9.4. Coordination with County FCD will be required. Current effort requires County FCD to get the toxicity results, with consultant working to interpret them and take follow-up samples at other receiving water and outfall sites.

Ongoing
Dependent on
timing of event
and obtaining
all necessary
data

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5 Program Management
The LWA Team’s overall approach for project management and successfully completing the project entails 1) Eﬀective Communication: providing the necessary communication mechanisms and check-in points with the City to ensure the project is meeting expectations; 2) Schedule Compliance: completing tasks on schedule; and 3) Budgetary Constraints: completing the project within the agreed-upon budget.

Through our Subconsultant Coordination method, we operate as a single uniﬁed consultant. Our high standard of work products and services is maintained by our Quality Assurance and Quality Control procedures. We have implemented the same management techniques on multiple similar large-scale monitoring projects to successfully meet our clients’ needs and deliver high-quality products. By selecting the LWA Team, the USCR CIMP Group is assured that an experienced team of professionals with proven project management experience and unique subject matter and technical expertise will successfully complete the tasks and ultimately achieve the project’s end goals. LWA’s proposed schedule is presented on a timeline chart in Figure 1.

5.1 Communication
In addition to the CIMP Group monthly check-in calls, the LWA Team will conduct internal team meetings at the project's onset and then have key check-ins during project implementation. Monthly meetings with the CIMP Group, along with Monthly Reports and monthly Post Event Reports, including presentations after submittal of the draft semi-annual and annual reports, all ensure that the LWA Team is not only keeping up with executing the monitoring itself but also data review and evaluation for water quality exceedances that require decision or action on the part of the CIMP Group. The LWA Team will develop standardized templates for meeting materials to minimize eﬀort in developing agendas, meeting minutes, and progress reports. Agendas will be prepared and distributed at least two business days prior to the meeting, and meeting summaries will be submitted electronically within ﬁve business days after the meeting date.

Additionally, the LWA Team can establish and maintain (or utilize an existing) a secure ﬁle-sharing site (e.g., Dropbox or SharePoint) to be used for the exchange of information and as a repository for the meeting materials (i.e., agenda, summaries, and presentations), project schedule, laboratory results, compiled data, and reporting materials. This approach, combined with our organizational structure and experience working together as a team, will minimize project management time and costs and maximize coordination of the project. Lastly, monthly invoices will be submitted with a cover letter clearly explaining the work completed associated with that invoice as well as a summary table of the month’s invoice, total invoice to date, remaining budget, and percent complete. Detailed invoices showing the total number of hours worked by each staﬀ member of the LWA Team will be attached to the cover letter.

5.2 Schedule Compliance
The LWA Team will utilize several mechanisms to track program implementation and ensure successful completion of work products on schedule. The LWA Team understands the project needs and will identify upcoming work that is certain and tasks that are ﬂuid but require advance preparation (e.g., wet weather monitoring). LWA goes through a monthly resource allocation process to ensure project needs are properly staﬀed. We regularly coordinate with the LWA Team members, coordinating agencies, and contracted laboratories to ensure everyone is prepared for upcoming monitoring events. The LWA

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Project Manager and lead staﬀ from sub-consultants are in regular communication regarding upcoming sampling events and have already deﬁned roles in working together on a number of projects – this includes processes for:
• Generating sampling paperwork, which is programmed so everything matches: bottle orders by laboratory, bottle labels, ﬁeld logs, chain-of-custody forms, constituent/bottle lists by site, constituent/bottle lists by lab.
• Contacting labs and coordinating bottle receipt, sample pickups, or delivery times. • Preparing sampling equipment.
• Tracking forecasts.
• Maintaining communication during the sampling event and having in-oﬃce support for questions or any unforeseen circumstances.
• Duplicate data quality review of lab data.

Furthermore, LWA maintains an internal Quality Review Process for all work products generated by LWA.

These procedures will be adhered to for all work produced under this contract, and the same standards will be required of all sub-consultants. Work products will also be reviewed by the Principal in Charge.

5.3 Budget and Project Staffing
The LWA Team will utilize several mechanisms to track program implementation and ensure successful completion of work products on budget. A key component of the management of the project is the identiﬁcation of our core project team developed as part of this proposal. We developed detailed estimates of labor hours and corresponding budgets. These eﬀorts resulted in our project staﬃng plan that supports project tracking that enhances our ability to work across our individual ﬁrms giving us the ability to work “in one oﬃce.” Maintaining the schedules with proper staﬃng allows our team to adhere to our proposed budget.

5.4 Subconsultant Coordination
One of the critical aspects of project management is the assembly of a team of subconsultants that have a shared interest in working together and a common understanding of the project scope and their role(s). Developing the team requires understanding the skills, expertise, and availability of team member staﬀ. With the proposed team and key personnel, along with our deep bench of highly qualiﬁed individuals, we can ensure that this project receives appropriate staﬃng and technical resources. We take great care in developing realistic staﬃng plans that account for both planned and unplanned absences that may require backup coverage. The ﬁrms that make up our team each understand their role and the commitment expected of them. LWA has worked with each of our subconsultants on similar projects for over ﬁve years.

5.5 Quality Assurance and Quality Control
The LWA Team has established procedures to ensure work products are of high quality. LWA maintains an internal Quality Review Process for all work products generated by LWA. These procedures will be adhered to for all work produced under this contract and the same standards will be required of all sub- consultants. Work products will also be reviewed by the Principal in Charge.

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Figure 1. Proposed Project Schedule

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6 Personnel, Equipment and Facilities
The LWA Team oﬀers highly capable managers and experts with experience on similar contracts. The LWA Team is built around Key Personnel with experience conducting monitoring, developing CIMPs, reporting monitoring results, and using those results to achieve compliance and eﬀect regulatory change. Roles have been assigned based on experience and availability throughout the term of the contract. The following provides a brief description of the proposed roles within our Team’s structure, followed by an organizational chart (Figure 2) and brief biographies of key personnel (Table 3).

Attachment A presents resumes for all personnel listed in Figure 2. Our team is structured as follows:

Principal in charge: Chris Minton (LWA) will serve as our Principal-in-Charge and is responsible for executing the contract. Additionally, he will assist with technical work related to regulatory and special study support. Mr. Minton has supported clients in the SCR watershed for over 15 years and has signiﬁcant experience working with the LWA Team members to implement complex projects.

Project Manager: David Vilas will be responsible for day-to-day project management and overseeing technical work. He will help ensure monitoring is conducted consistently with the CIMP's schedule and requirements.

Senior Advisor and Regulatory Support: In addition to staﬀ executing the CIMP , additional highly experienced Key Personnel who are experts in various technical areas (e.g., TMDLs, WMPs, bacteria, metals, etc.) were identiﬁed. These Key Personnel (Bryant Alvarado [LWA] and Aric Torreyson [Tetra Tech]) are available to assist the USCR WMG, Mr. Vilas, and Mr. Minton with specialized issues that arise during implementation of the contract.

Task Leads: The Task Leads (Bryant Alvarado [LWA] and Tim Tringali [Tetra Tech]) are experienced professionals with a unique combination of technical and regulatory expertise. These individuals were selected to successfully lead the major components of the scope of work outlined in the RFP , given their experience with these scope items on previous projects and their commitment to this project for the duration of the contract. The Task Leads will work closely with Mr. Vilas to deliver work products.

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Figure 2. Organizational Chart for the LWA Team

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Table 3. Biographies for LWA Team Management and Key Staﬀ Chris Minton has over 20 years of professional experience, including serving as LWA’s Project Manager on numerous
contracts for monitoring, regulatory support, and special studies. He has supported municipal clients in LA County with the renewal of NPDES permits, including supporting eﬀorts on the 2012 and current LA Regional MS4 Permit renewal process.

Mr. Minton led eﬀorts related to the development,
implementation, and adaptive management of multiple CIMPs.

Mr. Minton has worked closely with clients to engage on TMDLs: USEPA-led TMDLs (Santa Monica Bay PCBs and DDTs), third-party TMDLs (LA River Bacteria), and amended TMDLs (bacteria TMDLs in Ballona Creek). Additionally, Mr. Minton has led special studies related to bacteria and metals, which were incorporated into the LA Basin Plan as site-speciﬁc objectives and TMDL provisions.

David Vilas has more than 40 years of experience in freshwater and marine biology, with particular expertise in watershed-scale TMDL monitoring programs, multi-agency regulatory
compliance, and water-quality and biological community
assessments. He has extensive experience implementing
coordinated monitoring programs in Southern California
watersheds, including the Santa Clara River, San Gabriel River, Calleguas Creek, Ballona Creek, and Santa Ana River,
encompassing water-quality sampling, analysis of aquatic invertebrate and vertebrate communities, and sediment-quality assessments. At his previous employer, Mr. Vilas has served as Project Manager for the Calleguas Creek Watershed TMDL Monitoring Program since 2003, coordinating multi-media sampling (water, sediment, and tissue) and biological community evaluations in support of regulatory compliance — directly analogous to the multi-constituent, multi-agency structure of the Upper Santa Clara River CIMP . He is the Project Manager for the Upper Santa Clara River CIMP for LWA and leads the production of the Calleguas Creek Watershed TMDL Annual Report, managing a team delivering compliance reporting across ﬁve TMDLs simultaneously.

Bryant Alvarado has 14 years of experience developing site- speciﬁc objectives (SSOs), TMDLs, NPDES permit renewals and implementation, WMP adaptive management, and regulatory compliance. Mr. Alvarado leads the development of Semi- Annual WMP Progress Reports, Annual Monitoring Reports, and certain sections of Annual Report Forms for multiple Watershed Management Groups throughout Los Angeles County. He
assisted with the review and commented on the 2021 Los
Angeles Regional MS4 Permit, with an emphasis on the
monitoring, reporting, and TMDL provisions. Mr. Alvarado also supported the development of multiple aspects of WMPs,
including identifying water quality priorities and integrating WMP approaches to demonstrate compliance Bryant Alvarado
Associate I, LWA
Role: Technical Advisor, Task Lead for
Reporting and Adaptive Management
Areas of Expertise: CIMP monitoring,
reporting, and adaptive management;
data analysis; and TMDLs
Chris Minton
Vice President, LWA
Role: Principal-in-Charge
Areas of Expertise: CIMP
development, implementation, and
adaptive management; TMDL and
MS4 Permit; Special Studies

David Vilas
Senior I, LWA
Role: Project Manager
Areas of Expertise: CIMP
development, implementation, and
adaptive management; TMDL and
MS4 Permit; Special Studies

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with MS4 Permit requirements. Mr. Alvarado coordinates large monitoring projects; develops monitoring programs; works to develop SSOs; develops and implements TMDLs; and adaptively manages WMPs.

Michael Marson brings over 15 years of experience in the environmental ﬁeld and specializes in running watershed-based monitoring programs and data management. For these
programs, he manages all elements of the process, including ﬁeld crew and laboratory oversight; sub-consultant
management; database design and maintenance; equipment
installation and maintenance; sampling event preparation and paperwork; and post-event data QA/QC review, processing, and reporting. In addition to managing monitoring programs, Mr.

Marson also develops database tools to support increased eﬃciency and quality control. He has managed the monitoring activities and databases for the Malibu Creek Watershed CIMP , Calleguas Creek Watershed TMDL program, and the VCAILG monitoring program.

Sebastian Bognar supports clients with MS4 Permit and TMDL compliance, water quality monitoring, hydrology, data
visualization, and data analysis. Sebastian has served as an assistant task manager for LASAN’s Street Sweeping Study, where his responsibilities have spanned Work Plan development and sampling design, vendor and laboratory coordination, simulated street dirt preparation, and management of
controlled environment sweeper testing and street dirt
characterization sampling. Sebastian serves as a task leader for CIMP implementation and annual reporting across multiple City watersheds.

Adriel León has nine years of speciﬁc experience in stormwater management, watershed management, permit compliance,
policy analysis, water quality data analysis, and water quality monitoring. Mr. León organizes and manages the day-to-day eﬀorts of LWA’s LA Region MS4 Permit Reporting Team. He is responsible for coordinating the day-to-day activities of each team member as they work to complete the data analysis
components of the Annual Report (e.g., exceedances, trends, TMDL attainment) and compilation of the Watershed Form
using the Watershed Reporting, Adaptive Management and
Planning System (WRAMPS). Prior to joining LWA, Mr. León gained experience in water quality trading, regulatory factors inﬂuencing water market structure and viability, irrigated agriculture valuation, water valuation techniques, and water rights.

Michael Marson
Senior I, LWA
Role: Task Lead for Monitoring and
Data Management
Areas of Expertise: Management of
multi-faceted monitoring programs;
Database development and
management

Adriel Leon
Senior I, LWA
Role: Reporting and Adaptive
Management Task Support
Areas of Expertise: Water quality
monitoring and MS4 Permit
Reporting

Sebastian Bognar
Project Level II-A, LWA
Role: Task Support for Monitoring
and Data Management
Areas of Expertise: Areas of
Expertise: CIMP development,
implementation, TMDL and MS4
Permit; Special Studies

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7 Sub-Consultants
The LWA Team sub-consultant proposed for this project is Tetra Tech. Tetra Tech has more than 25 years of experience supporting stormwater management and regulatory compliance programs within Los Angeles County. This experience includes direct involvement in the development and implementation of CIMPs, including ongoing work in the USCR WMA.

Tetra Tech is currently implementing multiple CIMPs across the region, including the USCR CIMP , and has conducted more than 22 dry-weather and 41 wet-weather monitoring events at over 33 monitoring stations. These eﬀorts are supported by a team of more than 35 qualiﬁed local staﬀ, providing the capacity to eﬃciently mobilize and execute time-sensitive wet weather monitoring.

The team has a strong working knowledge of the USCR WMA, including the WMP and Reasonable Assurance Analysis (RAA), and understands how monitoring programs integrate with watershed-scale planning and compliance strategies. This experience is complemented by a thorough understanding of the current and tentative Regional MS4 Permit requirements and the TMDLs applicable to the USCR WMG.

In addition to core monitoring program implementation, Tetra Tech has planned and conducted targeted special studies, such as recreational beneﬁcial use assessments and natural background source investigations to support adaptive management and reﬁne watershed strategies.

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7.1 Subconsultant Project Experience
Examples of relevant projects led by Tetra Tech are provided below.

10. North Santa Monica Bay Coastal Watersheds CIMP Implementation Client City of Malibu
Dates of Service 2015-Present
Relevance to RFP Dry Weather Monitoring, Dry Weather Monitoring – Monthly Bacteria TMDL Monitoring, Wet Weather Monitoring, Source Identiﬁcation, Additional Monitoring Tetra Tech is currently under contract with the City of Malibu to implement the North Santa Monica Bay Coastal Watersheds CIMP on behalf of the City of Malibu, County of Los Angeles, and the LACFCD. The implementation of the CIMP includes stormwater outfall monitoring (wet and dry weather), receiving water monitoring (wet and dry weather), monthly and annual reporting, and consultation regarding other matters pertaining to the LA County MS4 Permit (e.g., Report of Waste Discharge, TMDLs, etc.).

Tetra Tech has been working closely with the NSMBCW WMG to track rain events and coordinate the activation of ﬁeld sampling teams. Tetra Tech has successfully completed the ﬁrst ﬁve years of wet-weather and dry-weather monitoring at the designated outfalls (2 total) and receiving water (3 total) sites.

In addition, Tetra Tech has been supporting the WMG with TMDL compliance monitoring and reporting for three TMDLs in the WMA. For implementation of the Malibu Creek and Lagoon Bacteria TMDL Compliance Monitoring Plan and the Malibu Creek Trash TMDL Monitoring and Reporting Plan, Tetra Tech partners with Clean Lakes, Inc. to monitor bacteria sites weekly and trash sites biweekly, respectively. Tetra Tech also coordinates with the City of Los Angeles monthly to obtain daily and weekly shoreline bacteria data for sites in the WMA, pursuant to the Santa Monica Bay Beaches (SMBB) Bacteria TMDLs Coordinated Shoreline Monitoring Plan. For all of these TMDLs, Tetra Tech prepares reports and submits them to the WMG monthly.

Tetra Tech leveraged a previously built water-quality database to reduce data management costs for the NSMBCW WMG. Referred to as EnDAR, the custom database has the following features:
• A website using Azure single sign-on for secure client access to reports. Reports provide access to all data (chemistry, ﬁeld parameters, habitat, toxicology, and bacteria). Weather conditions during sampling (dry vs. wet) are associated with chemistry results for report ﬁltering. • A data manager for such tasks as planning sampling events and uploading EDDs for reference, laboratory, and other data.
• A notiﬁcation system that emails users about system events such as data uploads, upload errors, and criteria exceedances.
• A SQL Server database for secure storage of all data. • Complete data traceability, including tracking of who uploaded data and when, maintaining a history of all changes, and archiving of all EDDs. Immediate, interactive feedback on upload status and error identiﬁcation is also provided.
• Imports and exports of data in CEDEN formats, as these CIMP Groups are required to report all their data to the Water Board every six months according to EDD templates developed by CEDEN.

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11. Central Coast Region Conditional Waiver Cooperative Monitoring Program Client Central Coast Water Quality Preservation, Inc. (CCWQP) Dates of Service 2012-Present
Relevance to RFP Dry Weather Monitoring, Wet Weather Monitoring, Reporting and Analysis, Toxicity, Source Identiﬁcation, Special Studies
TCCWQP manages the Cooperative Monitoring Program (CMP) on behalf of the irrigated agriculture industry on the Central Coast. The CMP is a surface water quality monitoring program that fulﬁlls a monitoring requirement for growers enrolled in the Central Coast Regional Water Quality Control Board’s (CCRWQCB) Conditional Waiver of Waste Discharge Requirements for Discharges from Irrigated Lands (“Ag Waiver”). The CMP is intended to track changes in surface water quality and Beneﬁcial Use support over time. The CMP comprises approximately 50 monthly monitoring sites located in seven Central Coast hydrologic units.

Monitoring includes chemical, physical, toxicological, and biological elements.

Since 2012, Tetra Tech has been implementing the monitoring and reporting program for CCWQP in accordance with an approved Sampling and Analysis Plan and a Quality Assurance Project Plan. A highly qualiﬁed team of scientists, toxicologists, and a data manager performs day-to-day support to CCWQP , including ﬁeld sampling, data validation, and EDD preparation.

Given the spatial breadth of the monitoring program, Tetra Tech uses experienced sampling technicians based in three oﬃces across the Central Coast to conduct monthly sampling safely and cost-eﬀectively.

Furthermore, Tetra Tech underwent a competitive bid process to select qualiﬁed laboratories for chemical, toxicological, and biological analyses. Tetra Tech uses a highly reﬁned process to prepare monthly ﬁeld sampling plans, ensuring clear communication of monitoring site requirements that vary monthly. All ﬁeld and lab data are compiled quarterly into a CEDEN-compliant EDD. All compiled data is validated by a Senior Environmental Scientist in accordance with the QAPP and a 10-point Quality Assurance Review protocol.

Since 2012, Tetra Tech has performed a variety of special studies and projects including, but not limited to geospatial analysis of agriculture impacted by proposed stream buﬀer regulations; statistical analysis related to pesticides occurrence within central coast watersheds, co-occurrence of toxicants and measured toxic eﬀects, and many others; database development; interpretation of regulations and assistance with stakeholder comment letters; and sample frequency reduction analysis.

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12. Coordinated Monitoring Program for Guadalupe River Watershed Mercury TMDL.

Client Santa Clara Valley Water District (Valley Water) Dates of Service 2018-2024
Relevance to RFP Dry Weather Monitoring, Wet Weather Monitoring, Toxicity, Source Identiﬁcation Tetra Tech implemented a ﬁve-year program to conduct monitoring and reporting in accordance with San Francisco Bay Regional Water Quality Control Board (RWQCB) requirements for the Guadalupe River Watershed Mercury TMDL. The Guadalupe River watershed lies within a region naturally enriched in mercury and covers approximately 170 square miles, draining portions of the eastern Santa Cruz Mountains to San Francisco Bay, and contains numerous tributary creeks and several reservoirs. The primary goals were to estimate mercury transport in the Guadalupe River during storms and to estimate total mercury loads to San Francisco Bay resulting from historic mercury mining activities in the watershed. Multiple mobilization criteria, including cumulative annual rainfall, reservoir status, predicted rainfall intensity, and peak ﬂows, were established to ensure that sediment mercury was mobilized and transported. Tetra Tech collected depth-integrated water samples throughout the storm hydrograph during two major (>2000 cfs) storms in each of two years. The program also included the determination of mercury and methylmercury concentrations in ﬁsh from tributary streams and reservoirs.

7.2 Subconsultant Staff Qualifications
Table 4. Tetra Tech Key Staﬀ
Aric Torreyson, PE, ENV SP, serves as Technical Advisor and provides executive oversight and strategic guidance for the implementation of complex stormwater and watershed
management programs. Mr. Torreyson has more than 24 years of experience in water resources engineering, environmental engineering, and infrastructure planning, including stormwater capture, watershed analysis, and regulatory compliance. He currently manages large multidisciplinary programs for federal, state, and local agencies. Mr. Torreyson has extensive experience supporting stormwater programs and regulatory compliance initiatives throughout Southern California. His work includes stormwater monitoring and reporting for Caltrans NPDES permit compliance, watershed modeling and pollutant loading analyses for regional stormwater capture projects, and the design of BMPs to address water-quality impairments. He has managed numerous multi-beneﬁt stormwater capture projects for Los Angeles County and municipal agencies, integrating hydrology and hydraulic analysis, water quality modeling, and regulatory coordination to reduce pollutant loading to impaired waterways.

Aric Torreyson, PE, ENV SP
Senior Program Manager, Tetra Tech
Role: Technical Advisor
Areas of Expertise: CIMP
development, implementation, and
adaptive management; TMDL and
MS4 Permit; Special Studies

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Tim Tringali has more than 18 years of experience assisting federal, state, and local entities to develop, implement and manage a variety of water resource programs. Much of his experience includes management of multi-disciplined teams to execute stormwater compliance programs for municipalities, the U.S. Air Force, and industry. Tim has provided technical support to multiple municipalities in Southern California with the development and implementation of their watershed
management plans and associated monitoring and assessment plans. Tim has managed multiple large-scale monitoring and reporting programs including for wastewater, stormwater, surface water, and discharges from irrigated agriculture. He has a strong understanding of the Los Angeles County MS4 Permit, TMDLs within LA County, and other related federal and state regulations. He’s knowledgeable of monitoring design and implementation strategies; deﬁning appropriate data quality objectives; and developing and managing water quality databases. His recent experience includes managing implementation of USCR and NSMBCW CIMPs, as well as designing and implementing monitoring programs for the Port of San Diego, Upper Los Angeles River WMG, and South Orange County.

Lauro Alvarado, EIT, is a water resources engineer with experience supporting stormwater monitoring programs, ﬁeld sampling, and data management for municipal watershed
monitoring initiatives. He has participated in the
implementation of several Coordinated Integrated Monitoring Programs in Southern California, including the Upper Santa Clara River CIMP and the North Santa Monica Bay Coastal Watersheds CIMP . Mr. Alvarado has extensive experience preparing and deploying monitoring equipment, conducting stormwater and receiving water sampling during wet and dry weather events, and documenting ﬁeld observations to support regulatory monitoring programs. He also provides data review and reporting support to ensure monitoring results meet MS4 permit and TMDL compliance requirements. In addition to ﬁeld monitoring activities, Mr. Alvarado supports monitoring database management and reporting, and has assisted in preparing Quality Assurance Project Plans for stormwater monitoring projects.

Gary Wortham is a Senior Environmental Scientist and aquatic toxicologist with more than 30 years of experience supporting stormwater, surface water, and sediment monitoring programs.

He specializes in quality assurance and quality control for environmental monitoring programs, including development of Quality Assurance Project Plans, Health and Safety Plans, sampling plans, and data validation procedures. Mr. Wortham has extensive experience implementing and reviewing
monitoring programs for municipal stormwater permits and watershed monitoring programs throughout California. He currently supports multiple Coordinated Integrated Monitoring Programs, including the Upper Santa Clara River and North Santa Monica Bay CIMP programs, where he manages QA/QC reviews of ﬁeld sampling and data reporting and validates electronic data deliverables submitted to CEDEN. His experience includes stormwater outfall monitoring, receiving Tim Tringali, CPESC, QISP ,
QSD/P
Senior Environmental Scientsit, Tetra
Tech
Role: Monitoring and Reporting
Support
Areas of Expertise: TMDL and MS4

Lauro Alvarado
Water Resources Engineer, Tetra Tech
Role: Monitoring Support
Areas of Expertise: Dry Weather
Monitoring, Wet Weather Monitoring
Gary Wortham
Senior Environmental Scientist, Tetra
Tech
Role: Monitoring Support
Areas of Expertise: Dry Weather
Monitoring, Wet Weather Monitoring,
MS4 Permit Compliance

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water monitoring, toxicity testing, and trace metals sampling using EPA ultra-clean techniques. Mr.

Wortham also has extensive experience supporting TMDL investigations, watershed monitoring programs, and MS4 storm drain characterization studies. For this project, he will lead QA/QC oversight, support data validation and reporting, and ensure monitoring data and analytical results meet all regulatory and permit requirements.

Jack Weil is an environmental scientist with experience supporting stormwater monitoring programs, regulatory
compliance eﬀorts, and environmental data analysis. His work focuses on ﬁeld monitoring and sampling, stormwater pollution prevention, and analysis of water quality data to support MS4 permit compliance and watershed management programs. Mr.

Weil has conducted stormwater monitoring for multiple
municipal programs, including the Upper Santa Clara River Coordinated Integrated Monitoring Program and the Port of San Diego's stormwater monitoring programs.

His responsibilities have included stormwater sampling during wet and dry weather events, sample logging and chain-of-custody documentation, and coordination with laboratory staﬀ to ensure proper analysis of collected samples.

Jack Weil
Scientist, Tetra Tech
Role: Monitoring Support
Areas of Expertise: Dry Weather
Monitoring, Wet Weather Monitoring,
MS4 Permit Compliance

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8 Optional Special Studies
Often, special studies ultimately lead to a scientiﬁc data collection eﬀort. Our Team, however, designs special studies to aﬀect policy. The LWA Team takes pride in the ability to develop and conduct special studies that result in revisions to the Basin Plan and TMDLs and ultimately support more reasonable implementation at a lower cost. From the outset, critical policy considerations are examined, including the underlying Basin Plan provisions, the dynamics of the Regional Board, potential constraints that may aﬀect USEPA approval (if needed), and precedent regarding other TMDLs and BPAs. This approach has led to special studies that successfully resulted in BPAs adopting SSOs developed by LWA for the Santa Clara River, Calleguas Creek, and Los Angeles River watersheds. No other team can match our track record of successful regulatory change driven by special studies.

LWA is committed to advocating on behalf of our municipal clients for fair and eﬀective environmental regulation. Our staﬀ actively participates in CASQA, CASA, and CWEA. These agencies focus on advancing regulatory and legal issues faced by their members. In each of these organizations, LWA staﬀ perform leadership roles from chairing committees to serving on their governing boards. Through these agencies, LWA works to address new regulations as they are developed, giving regulators context on whether the proposed actions are implementable. Using our established relationships, we negotiate with regulators to craft regulations that achieve their objectives while also providing thoughtful pathways to compliance.

Our ability to keep ahead of the curve on regulatory requirements provides a valuable perspective in the design and implementation of special studies.

Our Team understands there could be a broad range of special study-related services to support the Group’s eﬀorts to comply with TMDLs and water quality regulations. Special studies can help ensure long-term compliance with the Bacteria TMDL and address other RWL exceedances identiﬁed in the WMP (e.g., zinc, iron, mercury, and pesticides). Understanding the regulatory context allows our Team to recommend the appropriate scope and timing for studies and to identify future opportunities as regulatory conditions change. For example, the Regional Board’s 2020-2022 Triennial Review includes relevant priorities related to the continued development of tools to address natural sources of pollutants and updates to zinc criteria (also being considered by the State Board, which LWA has provided input on). Additionally, the evolution of bacteria water quality objectives (WQOs) at the federal and state levels provides an opportunity to apply the state of the science to move from an indicator to a risk-based framework that will result in more appropriate and eﬀective use of limited public resources.

Our Team will utilize the combined experience of multiple ﬁrms to implement these studies or any others that become a priority. It is imperative when developing special studies to understand the end goal fully and to avoid spending resources on science for the sake of science. As such, the cornerstone of our Team’s approach to supporting special studies is to start with determining the issues being addressed and the intended application of the study results. As demonstrated in the project descriptions and resumes, our Team has conducted numerous special studies in the Los Angeles region on bacteria, metals, and ammonia, including the only SSO studies that resulted in amendments to the Basin Plan and TMDLs. Our Team’s approach to conducting special studies will generally consist of the following elements:
• Working with the USCR CIMP Group to identify opportunities to develop and implement studies that will clearly support regulatory relief from inappropriate WQSs and/or directly support TMDL implementation eﬀorts (e.g., re-evaluation of WQSs and development of SSOs, bacteria source tracking, and utilization of QMRA/NSE, etc.);.

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• Building upon previous work conducted by the Group and other stakeholders. • Where available, using established regulatory guidance to inform the design of the study. • Developing work plans to identify the study’s purpose, hypotheses to be tested, study approach and methods, speciﬁc tasks, limitations of the study, and a QA/QC, data analysis, and reporting plan.
• For highly specialized or controversial work, identifying and utilizing a TAC to review the work plan and subsequent work products, as needed.
• Working with regulatory agencies to navigate the regulatory process to ensure the appropriate use of the generated information to revise the Basin Plan and/or justify TMDL revisions. • Conducting meetings to provide presentations and progress to the USCR CIMP Group, regulators, and other stakeholders and incorporate comments into the special studies.

For each of our Team’s completed special study projects, establishing relationships with regulatory agencies and leading scientiﬁc and policy experts was critical to success. While our Team’s special studies employed innovative approaches, the most important outcome is that they have assisted municipalities in achieving their ultimate goal – regulatory compliance. Four categories of special studies highlight the types of experience the LWA Team brings to the USCR CIMP Group:

1. Studies to address water quality objectives: Our Team has signiﬁcant experience with innovative special studies. Our Team members led eﬀorts on both the technical and policy aspects of special studies that form the basis for the only SSOs adopted by the Regional Board as BPAs: Los Angeles Region ammonia SSOs, Calleguas Creek Watershed copper SSOs, and LA River copper and lead SSOs.

The BPAs demonstrate our Team’s ability to identify opportunities to address inappropriate WQOs, develop and implement a technically sound approach, engage stakeholders, and see the project results through the regional, state, and federal regulatory processes.

2. Studies to address beneﬁcial uses: Our Team not only uses existing and current regulatory guidance, but we also identify creative approaches to eﬀect change. For example, our Team members worked with Regional Board staﬀ to utilize Basin Plan implementation provisions to support a beneﬁcial use change in the Santa Clara River using a streamlined approach to a Use Attainability Analysis.

This was the ﬁrst time such an approach was used, saving the client millions of dollars in wastewater operational costs.

3. Studies to characterize sources: We have developed some of the most advanced studies in the Region. The LA River BSI Study provides an excellent example of our Team's approach in developing characterization studies. Working with City of LA staﬀ, LWA Team members identiﬁed a need to characterize the contribution of bacteria to the LA River from the City’s water reclamation plants and MS4 system to support alternative approaches to allocations, implementation, and compliance. In the end, the BSI Study greatly inﬂuenced the LA River Bacteria TMDL and served as the scientiﬁc foundation for the development and implementation of the dry weather components and schedules.

4. Studies to support WMP/TMDL implementation: The LA River BSI Study set the foundation for the innovative dry weather load reduction strategy (LRS) compliance concept in the LA River Bacteria TMDL. The LWA Team has supported the development of LRSs for multiple waterbodies in the LA River. Services have included developing and implementing the monitoring component of the LRS, conducting statistical modeling to identify outfalls for implementation actions, and designing control options, including low-ﬂow diversions and green infrastructure.

City of Santa Clarita
Stormwater Monitoring Program and NPDES Compliance March 2026 | 53 Response File

8.1 New NPDES Permit Requirements and Optional BMP Monitoring The LWA Team’s expertise includes assistance with NPDES permit compliance, analysis of State and Federal water quality policies, implementation of watershed studies, and monitoring of surface waters, groundwaters, and waste streams. Our experience is directly applicable to incorporating new Permit requirements into the CIMP and its implementation, designing and performing special studies, and designing and implementing BMP monitoring. The data collected will help inform adjustments to the program to match new requirements in the future NPDES Permit, decide whether special studies may be beneﬁcial to perform, and highlight BMP monitoring to enhance our understanding of progress toward compliance. The future MS4 Permit requirements may result in revisions to the monitoring requirements related to the standard receiving water and outfall monitoring, as well as TMDL monitoring requirements. The LWA Team has included an optional task in our budget to update the CIMP if the USCR Group chooses to utilize this contract to do so.

8.2 Iron Study
Santa Clara River Reach 5 is currently on the 303(d) List for iron. The County evaluated wet- and dry- weather iron data generated by CIMP implementation and LACSD effluent monitoring. The County determined the available data did not support delisting; however, the USCR WMG believes there are natural/background sources of iron within the WMA. Examples of potential natural/background sources include aerial deposition and erosion from surrounding open space. The latter is likely exacerbated due to the frequent wildfires.

In advance of the 2030 Integrated Report cycle, the LWA Team would be available to perform an iron source investigation to identify and characterize potential sources and concentrations of iron in surface waters within the WMA. Beyond sample collection at targeted locations throughout the WMA, the study would employ an escalating, multiple line-of-evidence approach, including investigation of geologic information such as pyrite-bearing formations, well records for high-iron groundwater, and visual/microbial cues for the presence of iron in resurfacing groundwater. This approach will also support NSE if natural sources are determined to cause elevated concentrations. If the results of the study do not support delisting, developing an SSO may be warranted.

8.3 LREC 1
Use related studies would support the potential adoption of LREC-1, HFS, and/or a seasonal suspension.

A common theme across these regulatory options is ﬂow conditions (LREC-1 and seasonal suspension are related to low ﬂows and HFS is related to high ﬂows). The Statewide Bacteria Provisions do not provide speciﬁc guidance or deﬁnitions for what ﬂows are too high or too low to recreate in and the application of these approaches across the Regional Boards are not consistent. As such, there is an opportunity to develop and utilize an approach to determine when water depth is likely to be too low or too high to support REC-1 uses.

An approach that could be used (and has been used for HFS) to identify conditions that could reasonably correspond to low or high ﬂow conditions could be based on the research conducted by the Instream Flow Group (IFG), which was formed under the sponsorship of the U.S. Fish and Wildlife Service and funded by the USEPA. The IFG’s work evaluated methods of quantifying instream ﬂow needs for ﬁsh, wildlife, and recreation. The details of the REC research and ﬁndings were published in 1976 in Instream Flow Information Paper: No. 6 (Methods of Assessing Instream Flows for Recreation). The analysis recommends minimum and maximum depth and velocity conditions to support REC activities.

City of Santa Clarita
Stormwater Monitoring Program and NPDES Compliance March 2026 | 54 Response File
The IFG’s REC research resulted in depth and velocity criteria for supporting a variety of REC uses, including swimming, skiing, boating, and wading. Of the REC-1 uses analyzed by the IFG, Water Contact Wading is the “critical activity” because it requires the least amount of water depth, 3 inches, in order to support its users and sets safety criteria in terms of depth and velocity (see Figure 4). This information can be used to establish minimum and maximum thresholds. A critical aspect of our approach is the use of watershed models for the following components:

1. Supplement available ﬂow and rainfall data: analyses of the ability to recreate in low ﬂows or the safety of recreation during high ﬂows are based on water depth and velocity. Without a continuous ﬂow model, these parameters must be estimated using existing LA County ﬂow gages, which limits the number of locations that can be evaluated. The model can be used to assess conditions at any location in Reach 5, 6, or 7 and even the tributaries. In addition, the model will signiﬁcantly simplify analyses of alternative rainfall triggers for the HFS (other than the 0.5 inches utilized in the existing HFS).

2. Quantify the economic impacts of the HFS: use of the existing WMP/RAA model will allow us to quantify the cost beneﬁts of a regulatory change. The sizing and number of BMPs required to meet the TMDL with the HFS could be much less. These relate to costs which can be demonstrated to the Regional Board to support its adoption. These cost estimates can be used to encourage the Regional Board to extend the HFS to waterbodies that are not concrete -lined, a critical issue for the Santa Clara River.

In addition, one must consider the interplay between the HFS and the number of allowable wet weather exceedance days. In the Ballona Creek Bacteria TMDL, each HFS day reduced the number of allowable exceedance days. The LWA Team was able to revise the approach for the LA River Bacteria TMDL so that HFS days did not count against the number of allowable exceedance days.

As with special studies such as these, it is advantageous to ﬁrst conduct an initial evaluation to determine if the study results support a meaningful regulatory change. If the beneﬁt of the initial results warrants further pursuing a regulatory change, the next step is engagement with the Regional Board and stakeholders to develop an understanding of the technical and regulatory basis and start the process of incorporation into the Basin Plan.

These types of studies can often be completed primarily as a “desktop” exercise, given their reliance of historical ﬂow and rainfall records as well as modeling. As such, there is likely limited integration with the other required elements of the scope of work.

City of Santa Clarita
Stormwater Monitoring Program and NPDES Compliance March 2026 | 55 Response File

Figure 3. IFG Depth and Velocity Criteria for Supporting Water Contact Wading REC Uses

8.4 Natural Source Exclusion
The NSE approach may be utilized after all anthropogenic sources of bacteria are identiﬁed, quantiﬁed, and controlled. If applicable, the NSE, either incorporated directly into a TMDL or through a separate Basin Plan Amendment, would likely include a certain frequency of exceedance of the applicable bacteria water objectives based on the observed exceedance frequency of the identiﬁed and quantiﬁed natural sources of bacteria of the targeted waterbody. One potential approach to supporting an NSE is to utilize microbial source tracking methods (RNA/DNA methods) to evaluate the magnitude of human sources in a waterbody. One key challenge with the application of the approach is establishing a threshold for the level of human markers present in a waterbody, given the ubiquitous nature of human markers in the environment (including in recycled water runoﬀ). For example, San Diego Regional Board staﬀ proposed establishing a threshold through a TSO to support the potential application of the NSE approach.

City of Santa Clarita
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8.5 DNA/RNA Test Lab
Other applications of RNA/DNA testing are to 1) support implementation by focusing resources and targeting sources that pose the greatest risk (i.e., human sources), and 2) provide information to support a fundamental regulatory change in how we assess attainment of recreational beneﬁcial uses. RNA/DNA testing supporting implementation has been applied in multiple locations, including by the LWA Team in the LA River watershed. The most straightforward application is to collect human marker data in multiple locations within the target waterbody, as well as from outfalls over the course of multiple sampling events. This “synoptic” survey approach provides a robust dataset by which to conduct an assessment of potentially problematic areas and/or outfalls to focus implementation eﬀorts or prioritize for a later date if human markers are not present or at extremely low levels. Further, the collection of these data can be used to support alternative BMPs, such as a human source reduction approach that is focused on known sources within a drainage area rather than large BMP networks. Our Team has been working with permittees in the San Diego Region to utilize special study data to incorporate a human source reduction approach as the mechanism for demonstrating compliance with bacteria TMDL requirements in the San Diego Region’s MS4 permit.

Applying RNA/DNA testing to provide information to support a fundamental regulatory change in assessing attainment of recreational beneﬁcial uses is a vastly more complex challenge. Historically RNA/DNA testing has been utilized to demonstrate that other sources are present and causing or contributing to exceedances of traditional fecal bacteria indicators (FIB). While such testing has successfully shown that raccoons, birds, dogs, etc., are defecating in or near our MS4, these studies have not led to regulatory changes. Collection of human marker data (e.g., HF183) has also not, and is unlikely to, lead to the needed changes. Ultimately, it will take a more robust approach to data collection and analysis to support a move away from the current approach of solely relying on traditional FIB to a risk- based framework.

The potential approaches to address this issue can vary signiﬁcantly in terms of the level of eﬀort and costs. At the simplest end is the collection of human marker data to build a dataset that could in the future support discussions if the regulatory agencies, through some other means, come to accept such an approach. On the other end of the spectrum is conducting an assessment of the potential health risks to recreators through the collection of both human marker data and pathogens that would allow for the quantiﬁcation of risk levels.

Source-related studies can be resource-intensive, with two of the most extensive costs associated with sampling labor and laboratory analysis. Current ﬁeld eﬀorts and laboratory analysis could be leveraged to piggyback special study eﬀorts with existing eﬀorts.

8.6 Mercury Source Study
The LWA Team recently completed a preliminary assessment of total mercury for both outfall and receiving water sites and found that results higher than water quality objectives occurred overwhelmingly during wet weather events and at receiving water sites, with increasing trends for the Reach 5 and Reach 6 receiving water sites. The averages and medians for all sites are higher than the total mercury water quality objective. During a preliminary investigation into potential sources of mercury in the WMA, it was found that atmospheric deposition and wildfires could be large contributors, especially with an increase in wildfires in and near the WMA in recent years.

On request, the LWA Team will conduct an in-depth assessment of mercury in the WMA to provide supporting data and information identifying the prevalence of natural and/or background sources in receiving waters within the WMA. The Team has experience performing mercury studies for the USEPA

City of Santa Clarita
Stormwater Monitoring Program and NPDES Compliance March 2026 | 57 Response File
Region 10 and the Oregon Department of Environmental Quality (DEQ), among others. For USEPA and Oregon DEQ, the LWA Team developed a new Mercury TMDL for the Willamette River. The effort involved rigorous analysis of existing data to improve the analytical approach, as well as the development and implementation of a modeling framework that demonstrated that achieving lower methyl mercury tissue criteria in top-trophic-level fish would require substantial reductions in atmospheric deposition from global sources. Using the methylmercury criterion, scientists and engineers determined a total mercury target using a translator model. The TMDL underwent rigorous public and regulatory scrutiny and received final approval in early 2021. Depending on the results of the USCR assessment, a similar modeling approach could be used to identify a revised mercury target.

8.7 Pesticide Study
While pesticides can be a source of toxicity in receiving waters, municipalities have limited ability to control pesticide discharges. Pesticide use is regulated by the California Department of Pesticide Regulation (CDPR), and municipalities are legally prohibited from implementing measures that would limit its use. From a regulatory perspective, many pesticides lack established water-quality standards.

Therefore, special studies to support implementation or to modify water quality standards are unlikely to provide signiﬁcant beneﬁt.

The State Board is working on an alternative approach to addressing pesticides (Urban Pesticides Provisions Project) that leverages CDPR's legal authorities to modify the allowable uses and registrations of pesticides that have the potential to cause toxicity in receiving waters. To exercise their legal authorities, CDPR must have suﬃcient data demonstrating that pesticides are causing toxicity in receiving waters and identify the uses contributing to that toxicity to inform appropriate label changes.

The LWA Team is working with CASQA and the State Board on the development of the Urban Pesticides Provisions Project and has a strong understanding of both the regulatory approach and the monitoring proposed. Our Team would support the USCR WMG by coordinating with CDPR, as needed, to implement special studies that address CDPR’s data needs and support modiﬁcations to labels or registration status for problematic pesticides.

If the USCR WMG would still like to pursue a special study focused on pesticides, the LWA Team has experience in monitoring and assessing pesticide risk and setting pesticide standards at the federal, state, and local levels. Previously, the LWA Team provided technical assistance to the USEPA to develop the Pesticide General Permit. To help support the City of San Diego with Sediment Investigative Orders in San Diego Bay, the Team developed and implemented a sampling Work Plan that includes water and sediment sample analysis for pesticides. In addition, the LWA Team conducted a review and analysis of long-term data, which identiﬁed pyrethroid pesticides as a likely cause of biological impairment. A rapid causal assessment tool, customized for the Southern California region, has also been developed to quickly and cost-eﬀectively screen sites and identify stressors, such as pesticides, for further investigation. Ecotoxicology experts are also reviewing USEPA’s Federal Insecticide, Fungicide, and Rodenticide Act pesticide risk assessments and toxicity data. The LWA Team’s experience in pesticide monitoring, assessment, and regulatory support will ensure that pesticide source investigations for Bouquet Canyon meet the highest quality standards and that data eﬀectively translates to inform management decisions.

Special Studies Outputs
• Special study work plans.
• Technical memorandums.
• Laboratory analytical data reports and EDDs.

Attachment A.

Resumes
City of Santa Clarita
Stormwater Monitoring Program
and NPDES Permit Compliance
David Vilas
Project Experience

David Vilas
Senior Scientist I
Professional Experience

Mr. Vilas has more than 40 years of experience in freshwater and marine biology, with particular expertise in watershed-scale TMDL monitoring programs, multi-agency regulatory compliance, and water-quality and biological community assessments. He has extensive experience implementing coordinated monitoring programs in Southern California watersheds, including the Santa Clara River, San Gabriel River, Calleguas Creek, Ballona Creek, and Santa Ana River, encompassing water-quality sampling, analysis of aquatic invertebrate and vertebrate communities, and sediment-quality assessments. At his previous employer, Mr. Vilas has served as Project Manager for the Calleguas Creek Watershed TMDL Monitoring Program since 2003, coordinating multi-media sampling (water, sediment, and tissue) and biological community evaluations in support of regulatory compliance — directly analogous to the multi-constituent, multi-agency structure of the Upper Santa Clara River CIMP. He is the Project Manager for the Upper Santa Clara River CIMP for LWA and leads the production of the Calleguas Creek Watershed TMDL Annual Report, managing a team delivering compliance reporting across five TMDLs simultaneously.

Upper Santa Clara River Coordinated Integrated Monitoring Program. 2022-Present Project Manager leading a team providing support to the City of Santa Clarita and the County of Los Angeles for the Upper Santa Clara River Watershed Management Program Group, with annual reporting and CIMP implementation support. Prepared Annual Reports containing the elements described in the CIMP and the requirements of the MS4 Permit, including descriptions of implementation and monitoring efforts completed during the reporting year. Prepared Semi-Annual Data Reports in accordance with the requirements of the MS4 Permit. Analyzed monitoring data collected by all CIMP participants.

Calleguas Creek Watershed TMDL Monitoring Program. 2003-2022 Project Manager. Assisted in the development of the monitoring program to evaluate nutrients and contaminants in water, sediment and tissue of resident species in Mugu Lagoon, at the mouth of Calleguas Creek. Coordinated quarterly water sampling and analysis in the lagoon, and tri-annual collection of sediment and fish and mussel tissue samples for analysis. Analyzed benthic infauna samples and evaluated biological community parameters as part of the sediment quality objective (SQO) sampling triad.

Maintains necessary clearances to access the lagoon within the Pt. Mugu Naval Air Station, and works closely with base biologists to minimize disturbance of protected species during sampling. 2003 through 2022.

Watershed Program Compliance Monitoring and Regulatory Support, Calleguas Creek Watershed. 2024-Present. CA.

Assistant Project Manager and contributor in providing program and regulatory support for the Participating Agencies implementing TMDLs in the Calleguas Creek Watershed.

Facilitated, managed, and overseen the production of the TMDL Annual Report for the Calleguas Creek Watershed group. To support this effort, organized and led a team to complete an annual monitoring report for compliance with 5 TMDLs: Salts TMDL, OC Pesticides TMDL, Nutrients TMDL, Toxicity TMDL, and Metals TMDL. Example tasks include: project management, document preparation, participation in meetings, analyzing annual monitoring data and developing relevant supporting figures and tables for all constituents as required
Education
Graduate Studies, 1983-
1986, Moss Landing Marine
Laboratories

B.A., Biology, 1983,
University of California,
Santa Cruz,
Santa Cruz, CA
Years of Experience
With LWA: 4
With Other Firms: >40
Professional Affiliations
Southern California
Association of Marine
Invertebrate Taxonomists
(SCAMIT), Member

Orange County Marine
Protected Area Council
(OCMPAC), Member

David Vilas
Project Experience
Los Angeles River Temperature Study. 2023 – Present. Los Angeles County Assistant Project Manager assisting the Cities of Los Angeles and Burbank in responding to a new water quality objective for temperature. LWA is assisting the cities in developing and implementing a temperature study to better understand the temperature range protective of the WARM beneficial use. To do this, LWA and the Cities, in consultation with a Technical Advisory Committee, are evaluating aquatic life uses in each waterbody to characterize the relationship between water temperature and the ability of each waterbody to support warm-water aquatic life. LWA developed and is implementing a Workplan designed to fill data gaps identified as critical to addressing study goals.

Ongoing.

Recalculation of the Acute Zinc Criterion in the Los Angeles River, Ballona Creek, and Dominguez Channel Watersheds. 2022 – Present. Los Angeles County.

Project Scientist assisting the City of Los Angeles Sanitation and Environment by providing a summary of the occurrence of aquatic vertebrate and invertebrate species in the Los Angeles River, Ballona Creek, and Dominguez Channel Watersheds, locations within three watersheds in the Los Angeles region. Utilizing updated information since the existing Total Maximum Daily Loads were developed, the study will update zinc criterion, if appropriate, to develop site-specific objectives (SSOs) for zinc based on the most recent available toxicity data and site-specific considerations.

San Gabriel River Temperature Study. 2022 – Present. Los Angeles County.

Assistant Project Manager assisting the Los Angeles County Sanitation Districts ( in developing Districts) respond to a new water quality objective for temperature. LWA is assisting the Districts in developing and implementing a temperature study to better understand the temperature range protective of the WARM beneficial use. To do this, LWA and the Districts, in consultation with a Technical Advisory Committee, are evaluating aquatic life uses in each waterbody to characterize the relationship between water temperature and the ability of each waterbody to support warm-water aquatic life. LWA developed a work plan which outlined technical studies designed to fill data gaps identified as critical to addressing these study goals.

Los Angeles River Watershed Copper Water-Effects Ratio and Lead Recalculation Study.

Project Manager, alongside Larry Walker Associates under contract to a consortium of Los Angeles River dischargers, provided specialized and expert services to support the implementation of the Los Angeles River and Tributaries Metals Total Maximum Daily Load (TMDL) work plan. MBC was selected to provide support services to LWA in the collection and processing of field and analytical chemistry data for Water-Effects Ratio (WER) determinations for the Los Angeles River and tributaries. The study included dry weather and stormwater collection events at multiple sites along the Los Angeles River and tributaries. MBC provided additional support by compiling information on biological organisms present in the Los Angeles River and its tributaries to assist in developing WERs based upon the California Toxics Rule criteria for copper and lead.

Ballona Creek Bacteria Total Maximum Daily Load (TMDL) Project Environmental Impact Report (EIR).

Project Manager. Analyzed potential impacts to the biological communities and sensitive species in the creek as a result of the project proposed a suite of three projects to reduce bacteria in the Ballona Creek Watershed, and its alternatives. Attended public meetings at the initiation of the EIR process to listen to questions and concerns from the public and inform the community of project aspects. Another public meeting was attended when the draft EIR was released to discuss the analysis results and answer questions from the engaged participants. The final EIR was adopted by the Board of Public Works in April 2018.

Environmental Impact Report (EIR) and Environmental Impact Statement (EIS) Preparation.

Responsible for preparing marine biological and oceanographic sections and technical documents for EIRs and EISs to evaluate potential environmental effects from multiple projects. Examples of projects include the Long Beach Naval Station EIS, the LA-3 Ocean Dredged Material Disposal Site Designation EIS, the Chula Vista Redevelopment Project, the LA Co. Sanitation District Clearwater Program EIR/EIS (Project Manager), the Port of Los Angeles APL Terminal EIS/EIR, the Port of Los Angeles Al Larson Boat Shop EIR, Port of Los Angeles YTI Terminal Project (Project Manager), Port of Long Beach Fireboat 20 IS/MND (Project Manager), Port of Los Angeles Pier 400 Railyard Extension IS/MND (Project Manager), Port of Los Angeles Star-Kist Cannery Facility Project IS/MND (Project Manager), and for desalination projects at Santa Monica Bay, Long Beach, Huntington Beach and Encina (Project Manager). 2002 through 2022. Also provided third-party reviews of several EIRs and EISs since 2000.

Project Experience

Chris Minton
Vice President
Professional Experience

Mr. Minton has supported clients with negotiations on National Pollutant Discharge Elimination System (NPDES) permit requirements for both stormwater and wastewater programs, development and implementation of monitoring programs to address NPDES permit requirements for both stormwater and wastewater; as well as to conduct special studies; manage, develop and implement Watershed Management Program and Total Maximum Daily Load (TMDL) implementation planning processes and monitoring programs; site-specific objectives studies; and field investigation studies.

Mr. Minton has supported clients with negotiations on National Pollutant Discharge Elimination System (NPDES) permits for both stormwater and wastewater; managed, led development of Watershed Management Programs (WMPs) and Coordinated Integrated Monitoring Programs (CIMPs); led development of special studies using USEPA’s Water- Effect Ratio (WER) and Recalculation procedures; and supported clients develop and negotiate Total Maximum Daily Loads (TMDLs).

City of Los Angeles Sanitation and Environment (LASAN) On-Call Planning and Technical Support for the Clean Water (Wastewater), Environmental Quality, Solid Resources, and Watershed Protection Programs. 2014-Present LWA Project Manager for the LASAN On-Call Personal Services Contracts. As the prime contractor, successfully led consultant teams provide a range of stormwater and wastewater related regulatory and monitoring services to LASAN under TOSs SN-21, 34, 44, 84, 95, 110, 124, 130, 140, 141, 142, and S-004A, B, and C. LWA Project Manager as a subconsultant on TOSs SN-53, 61, 102, 119, 135, and 171.

LASAN Watershed Protection Division (WPD): Monitoring, Reporting, Regulatory and Study Support. 2008-Present
Project Manager for over 16 years on multiple WPD on-call services contracts related to addressing technical and regulatory challenges associated with TMDLs, MS4 Permit, water quality criteria, and monitoring. Responsibilities include identifying developing and implementing project approaches and managing individual project efforts. Specific relevant projects include:
 Project Manager for providing as-needed monitoring and reporting services to the ULAR, BC, SMB J2/3, and DC Watershed Management Groups (WMP) Groups. Monitoring support has included load reduction strategy monitoring, wet and dry weather monitoring, identification of significant non-stormwater discharges, and non-stormwater source investigations. Support reporting in various capacities for all four WMP Groups with a primary focus on reporting monitoring results.
 Developed strategy and conducted technical analysis in support of TMDL revisions for the BC Toxics, Metals, and Bacteria TMDL and the Santa Monica Bay Dry and Weather Bacteria TMDLs and the Marina del Rey Bacteria TMDL that resulted in changes to allocations and compliance schedules.
 Reviewed, commented, and supported negotiations on the following TMDLs developed by the Regional Board and/or USEPA: Dominguez Channel and LA/Long Beach Harbors Toxics TMDLs, Machado Lake Toxics, Santa Monica Bay Marine Debris, Los Angeles Area Lakes, Los Cerritos Channel Bacteria.
 Developed comments on regulatory requirements including: updates and revisions to the 303(d) List; Los Angeles Region Triennial Review; California’s Water Quality Education
M.S., Environmental
Science & Management,
2002,
Bren School of
Environmental Science and
Management, University of
California, Santa Barbara

B.S., Geology, 1998,
University of Washington,
Seattle
Years of Experience
With LWA: 18
With Other Firms: 2

Project Experience
Enforcement Policy; Sediment Quality Objectives; California’s General Permits for Industrial Discharges, Construction Discharges, and Phase II Dischargers; MS4 Permit Reporting Policy; and Los Angeles Region Copper Biotic Ligand Model Implementation Report.

LASAN Regulatory Affairs Division (RAD). On-Call Services. 2008-Present Project Manager for multiple RAD contracts providing on-call services to address regulatory challenges related to various City operations, including the four water reclamation plants (WRPs). Managed a team of over 30 subcontractors with wide-ranging capabilities to provide support for short and long term projects. Directly managed and provided technical support including: review and negotiation support on the reissuance of NPDES permits for all City WRPs, Basin Plan Triennial review, 303(d) listings, field investigation of NDMA, reasonable potential analysis.

Site Specific Objective Special Studies. 2002-Present
Assisted multiple clients with special studies in support of the TMDLs in the LA Region. Worked on all four site- specific objective (SSO) special studies that formed the basis for revisions to the Basin Plan, TMDLs and NPDES Permits.

Performed a lead role related to monitoring implementation and data analysis for the LA Region Ammonia SSO Study and the Calleguas Creek and Mugu Lagoon Copper WER, and LA River Copper WER for City of LA and Burbank WRPs. Lead the LA River Copper WER and Lead Recalculation Study for stormwater agencies representing over 35 cities, LA County, and Caltrans. Evaluated water quality data to assess compliance with the TMDL and development of the Preliminary Work Plan to evaluate how USEPA’s WER and Recalculation Procedure could be ut ilized. Developed a watershed wide SSO Work Plan. Negotiated the requirements with the Regional Board and an independent Technical Advisory Committee (TAC). Managed implementation of the approved Work Plan comprised of 1) WER monitoring in the LA River and major tributaries, critical conditions analysis, WER calculation, and report development; and 2) engagement with USEPA to obtain an approved updated lead toxicity dataset, data evaluation, criteria calculation, sensitive species identification and analysis, and report development. Developed an implementation report outlining how the SSOs should be incorporated into the Basin Plan and the TMDL and addressed requirements related to antidegradation, anti-backsliding, and future monitoring. Responsible for negotiating utilization of results of the studies into the TMDL and NPDES permits leading to compliance with the copper and lead limits for MS4 Permittees. Currently leading the implementation of a Safe, Clean Water Program special study to recalculate the aq uatic life criterion for zinc in the LA River, BC, and DC watersheds.

Safe, Clean Water Program (SCWP) Scientific Study Support. 2021-Present Assisted LASAN WPD with the development of Scientific Study applications for submittal to the SCWP: Zinc Criteria Recalculation, Street Sweeping, and Land Use. Managed implementation of the Zinc Criteria Recalculation Study, including supporting LASAN meet SCWP reporting requirements. Managed implementation of Phase I of the Street Sweeping Study to complete testing of multiple street sweeping technologies (i.e., mechanical broom versus regenerative air) to evaluate efficacy and position LASAN to quickly transition to Phase II of the study using SCWP funding.

Los Angeles Region MS4 Permit Renewal. 2011-2012 and 2019-2021 Project Manager responsible for assisting LASAN on the MS4 permit renewal process for the 2012 and 2021 permits.

Support included meeting consistently with LASAN and Regional Board staff to negotiate the Permits, developing detailed technical and regulatory comments, and supporting the City at Regional Board workshops and adoption hearings. Developed several approaches that were utilized by the Regional Board as the basis for key permit sections, including (1) watershed-based permit structure, (2) BMP-based compliance options, (3) utilizing the WMPs as a compliance option for the Receiving Water Limitations provisions, (4) development of the WMP that incorporates all elements of the Permit, but allows Permittees to focus efforts on identified water quality i ssues, and (5) development of alternatives to the MS4 monitoring program resulting in flexibility with monitoring implementation. Key outcomes of the 2021 renewal process were the maintenance of implementation-based compliance for interim TMDL limits and receiving water limitations and minimizing changes to monitoring and reporting requirements.

Project Experience

Bryant Alvarado
Associate
Professional Experience

Mr. Alvarado is an Associate and has experience in multiple water quality service areas, including the development of stormwater watershed management programs (WMPs); coordinated integrated monitoring programs (CIMPs); stormwater annual reporting; ambient and agricultural water quality monitoring; Total Maximum Daily Load (TMDL) development and implementation; National Pollutant Discharge Elimination System (NPDES) permit renewals and implementation; and site-specific objectives (SSOs).

Upper Santa Clara River Coordinated Integrated Monitoring Program. 2021-Present Assistant Project Manager leading a team providing support to the City of Santa Clarita and the County of Los Angeles for the Upper Santa Clara River Watershed Management Program Group, with annual reporting and CIMP implementation support. Prepared Annual Reports containing the elements described in the CIMP and the requirements of the MS4 Permit, including descriptions of implementation and monitoring efforts completed during the reporting year. Prepared Semi-Annual Data Reports in accordance with the requirements of the MS4 Permit. Analyzed monitoring data collected by all CIMP participants.

Upper San Gabriel River Watershed Coordinated Integrated Monitoring Program: As- Needed Consultant Services and Annual Reporting. 2019-Present Assistant Project Manager leading a team providing support to the Los Angeles County Public Works to provide the Upper San Gabriel River Watershed Management Program Group with annual reporting and CIMP implementation support. Prepared Annual Reports containing the elements described in the CIMP and the requirements of the MS4 Permit, including descriptions of implementation and monitoring efforts completed during the reporting year. Prepared Semi-Annual Data Reports in accordance with the requirements of the MS4 Permit. Installed equipment and conducted monitoring. Analyzed readily available monitoring data collected by the LACFCD, other watershed management program groups, Los Angeles County Sanitation Districts, San Gabriel River Regional Monitoring Program, and relevant special studies.

Los Angeles Region CIMP Development. 2013-2015 and 2021-Present Led the development of multiple aspects of the original CIMPs for six Watershed Management Groups (WMGs) and led the update to all five of the City of Los Angeles -led CIMPs as well as four other CIMPs across Los Angeles County. The aspects of the CIMPs that were led include developing a receiving water monitoring approach that integrates TMDL and MS4 Permit receiving water monitoring requirements and identifying outfall and receiving water monitoring sites. Regarding site selection, selected sites that utilize the criteria outlined in the receiving water monitoring approach and separately developed stormwater outfall monitoring approach, while ensuring that all proposed sites are safe and accessible. Responded to comments made by the Los Angeles Regional Water Quality Control Board (Regional Board), met with Regional Board staff to discuss proposed revisions, and revised the CIMP to obtain approval.

CIMP Annual Reporting. 2015-Present
Coordinated responses for all monitoring-related questions for five City of Los Angeles-led WMGs. Led the development of the sections of the annual report providing the assessment results of whether the receiving water quality is improving, declining, or staying the same.

Evaluated receiving water, stormwater outfall, and non-stormwater outfall data for exceedances.

Education
M.S., Civil and
Environmental Engineering,
2011,
Stanford University,
Stanford, CA

B.S., Environmental
Engineering, 2009,
Florida International
University, Miami, FL

Years of Experience
With LWA: 14

Project Experience
City of Los Angeles WMAs Wet Weather Monitoring Programs. 2015-Present Coordinated wet weather events by reviewing responsibilities with field crews and discussing any modifications to the approach taken during previous events to incorporate lessons learned and storm characteristics. Provided direction to subcontractors for supporting monitoring of their respective sites and communicated with LASAN staff r egarding timing of sample collection and delivery during wet weather events. Gathered field logs and photographs from subcontractors, requested necessary revisions/corrections, and sent them to LASAN. Coordinated the preparation of receiving water and outfall monitoring sites in advance of the upcoming wet weather events. After the events were completed, recommendations were provided to LASAN regarding QA/QC validation and reporting.

Ballona Creek and Upper Los Angeles River EWMP Development. 2013-2016 Supported the development of multiple aspects of the original EWMPs for the Ballona Creek and Upper Los Angeles River WMGs. Supported the identification of water quality priorities and integration of the EWMP approaches to demonstrate compliance with MS4 Permit requirements.

City of Los Angeles WMAs Non-Stormwater Outfall Source Identifications and Investigations. 2015-2017 Led multi-team non-stormwater (NSW) screening events for Arroyo Seco and coordinated NSW screening events for Los Angeles River Segment E and Compton Creek. Led the development of technical memoranda identifying outfalls with significant NSW discharges, utilizing innovative approaches consistent with the CIMP. Outlined an approach for conducting NSW source investigations. Incorporated comments from the City of LA into the source investigation approach and coordinated source investigations within the Ballona Creek, Dominguez Channel, Los Angeles River, and Santa Monica Bay Jurisdictional Group 2/3 watersheds to identify the source for outfalls with significant NSW discharges. Led the development of technical memoranda detailing the results of the source investigations and incorporated comments from City of Los Angeles prior to finalizing.

Ballona Creek Watershed TMDL Reopeners. 2012-2013
Assisted with the review of and commenting on the Tentative Basin Plan Amendments for the Ballona Creek Metals TMDL and the Ballona Creek Estuary Toxic Pollutants TMDL. Provided technical support for the successful negotiation of revised TMDL compliance options and implementation schedules.

Santa Clara River Chloride Site-Specific Objectives and Antidegradation Analysis. 2012 To reflect modifications to the implementation strategy, updated an SSO and antidegradation analysis report for the Sanitation Districts of Los Angeles County, which provided the technical and regulatory basis for consideration of SSOs for surface water in Reaches 4B, 5, and 6 of the Santa Clara River.

Third-Party Selenium TMDLs for the Newport Bay Watershed. 2014 Prepared the initial drafts of multiple sections of a third-party TMDL written to address selenium impairments in the Newport Bay watershed. Drafted TMDL sections include the problem statement, numeric targets, and the monitoring portion of the implementation plan. Led the development and incorporation of all TMDL appendices and supported the incorporation of all comments on the initial and revised drafts of the TMDL to produce draft final versions of the TMDL.

San Diego Region Phase I Bacteria TMDL Reopener Support & Reporting. 2015 -2017 Supported the development of a Preliminary Technical Report document, which presented potential concepts for regulatory updates (while also providing the technical foundation to evaluate potential revisions) to the Water Quality Control Plan for the San Diego Basin, as well as the Revised Total Maximum Daily Loads for Indic ator Bacteria, Project I.

Twenty Beaches and Creeks in the San Diego Region (Including Tecolote Creek). 2017 Served as the primary author on (or oversaw the development of) sections related to the TMDL current conditions analysis, potential revisions to REC-2 objectives, and implementation provisions associated with the reference system/antidegradation approach, temporary suspension of uses, and variances. As applicable, provided potential language to incorporate these concepts into the Basin Plan.

Project Experience

Adriel León
Senior Scientist I
Professional Experience

Mr. Adriel León is a Project Scientist at LWA and has professional experience in multiple water quality service areas, including stormwater management and monitoring programs, watershed management, agricultural water quality, Total Maximum Daily Load (TMDL) implementation, stormwater reporting, watershed management, permit compliance, policy analysis, water quality data analysis, and water quality monitoring. Mr. León joined LWA after completing his graduate degree at the University of California, Santa Barbara.

Upper San Gabriel River Watershed Coordinated Integrated Monitoring Program (CIMP) As-Needed Consultant Services, County of Los Angeles. 2019-Present. Los Angeles County, CA.

Project Manager responsible for supporting the Los Angeles County Department of Public Works to provide the Upper San Gabriel River Enhanced Watershed Management Program Group (USGREWMP Group) with annual reporting and Coordinated Integrated Monitoring Program (CIMP) implementation support. Responsibilities include preparing Annual Monitoring Reports, Semi-Annual Reports, and Watershed Management Program Progress Report forms. These deliverables include elements described in the CIMP and the requirements of the municipal separate storm sewer system (MS4) permit, for submittal to the Los Angeles Regional Water Board, including descriptions of implementation and monitoring efforts completed during the reporting year.

Ventura Countywide Stormwater Management Program Coordinated Integrated Monitoring Program (CIMP) Support, Ventura County Watershed Protection District. 2022-Present. Ventura County, CA.

Project Manager responsible for supporting the development of the Coordinated Integrated Monitoring Program (CIMP). Responsibilities include supporting the integration of TMDL monitoring requirements into the CIMP, providing regulatory interpretation support for municipal separate storm sewer system (MS4) permits, and providing technical support to develop approaches for specific CIMP elements.

Malibu Creek Coordinated Integrated Monitoring Program (CIMP) Annual Reporting, City of Agoura Hills. 2016-Present. Agoura Hills, CA.

Assistant Project Manager responsible for compiling stormwater program activities, data, and data analysis results to complete Annual Monitoring Reports, Semi-Annual Reports, and Watershed Management Program Progress Report form as part of municipal separate storm sewer system (MS4) permit monitoring and reporting requirements. Completion of this report includes compliance evaluations of TMDLs, hydrologic condition summaries, and constituent trend analyses.

Coordinated Integrated Monitoring Program (CIMP) Wet Weather Monitoring Programs, City of Los Angeles. 2016-Present. Los Angeles, CA.

Assistant Project Manager responsible for coordination of receiving water and storm water outfall sampling in accordance with the Coordinated Integrated Monitoring Program (CIMP) for the Santa Monica Bay Jurisdictions 2 and 3, Upper Los Angeles River, and Dominguez Channel watersheds. Responsibilities include coordinating with City staff to collect and distribute monitoring equipment and paperwork as well as overseeing completion of monitoring photos and field log deliverables.

Education
M.S., Environmental Science
and Management, Water
Resources Concentration,
2016, Bren School of
Environmental Science &
Management, University of
California, Santa Barbara,
CA

B.S., Biology, 2010, Loyola
Marymount University, Los
Angeles, CA
Years of Experience
With LWA: 7
With Other Firms: 0
Professional Affiliations
California Stormwater
Quality Association
(CASQA), Member
Work Tools
ESRI ArcGIS
R/Rstudio

Project Experience
Malibu Creek Coordinated Integrated Monitoring Program (CIMP) Monitoring and Screening, City of Agoura Hills. 2016-Present. Agoura Hills, CA.

Field Lead responsible for conducting non-stormwater and wet weather preparation and monitoring of receiving waters and outfalls in accordance with the Coordinated Integrated Monitoring Program (CIMP) for the Malibu Creek watershed. Conducted non-stormwater source investigations for significant discharges to outfalls.

Upper San Gabriel River Coordinated Integrated Monitoring Program (CIMP) Monitoring, County of Los Angeles. 2019-2021. Los Angeles, CA.

Field Lead responsible for conducting wet weather preparation and monitoring of receiving waters and outfalls in accordance with the Coordinated Integrated Monitoring Program (CIMP) for the Upper San Gabriel River watershed.

Regulatory Support, Ventura County Agricultural Irrigated Lands Group (VCAILG). 2016 -Present. Ventura County, CA.

Project Manager responsible for the completion of the Annual Monitoring Report summarizing monitoring activities required by the Conditional Waiver of Waste Discharge Requirements for Discharges from Irrigated Lands within the Los Angeles Region (Conditional Waiver).Conducted exceedance evaluations of monitoring data for receiving waters and agricultural drains in accordance with Conditional Waiver water quality benchmarks and TMDL allocations as part of three iterations of Water Quality Management Plans in 2016, 2017, and 2020. Additional support includes preparing comment letters on proposed regulatory policies; developing comments on the 2023 General Waste Discharge Requirements for Discharges from Irrigated Agricultural Land within the Los Angeles Region (Ag Order); and providing development, implementation, and monitoring assistance for all Ventura County TMDLs in which agriculture is a responsible party.

Stormwater Reporting Support, City of Los Angeles. 2016-Present. Los Angeles, CA.

Assistant Project Manager responsible for compiling stormwater program activities, data, and data analysis results to complete Annual Monitoring Reports, Semi-Annual Reports, and Watershed Management Program Progress Report form for the Santa Monica Bay Jurisdictions 2 and 3, Santa Monica Bay Jurisdiction 7, Upper Los Angeles River, Ballona Creek, and Dominguez Channel Watershed Management Areas (WMAs) as part of municipal separate storm sewer system (MS4) permit monitoring and reporting requirements. Completion of these reports includes compliance evaluations of watershed-specific TMDLs, hydrologic condition summaries, and constituent trend analyses. Mr. León assists with additional technical support requests such as permit compliance analyses, policy evaluations, development of comment letters, and water quality data analysis training.

As-Needed Regulatory Support, City of Los Angeles. 2016-Present. Los Angeles, CA.

Assistant Project Manager responsible for as-needed regulatory support. Provides review of policy documents , including draft municipal separate storm sewer system (MS4) permits, TMDL Basin Plan amendments, and the Clean Water Act Section 303(d) List of Impaired Water Bodies. Prepares Semi-Annual Data Reports, including comparison of data to water quality objectives in accordance with the requirements of the MS4 Permit for submittal to the Los Angeles Regional Water Quality Control Board (Regional Water Board).

Calleguas Creek Watershed Management Plan TMDL Implementation, Stakeholders Implementing TMDLs in the Calleguas Creek Watershed. 2016–Present. Ventura County, CA.

Contributes to the production of the Annual Monitoring Report summarizing monitoring activities conducted for the effective TMDLs for toxicity, organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and sediment, metals and selenium, and salts in the Calleguas Creek watershed. Completion of this report includes extensive review and preparation of water quality, toxicity, sediment, and fish tissue data, including the analysis of data in comparison to the applicable compliance targets or allocations. Additional support includes preparing comment letters on proposed regulatory policies, conducting data analysis and reporting, and evaluating compliance with TMDL allocations.

Upper Santa Clara River Enhanced Watershed Management Program (EWMP) Revisions, County of Los Angeles. 2021. Los Angeles County, CA.

Assistant Project Manager responsible for day-to-day completion of data analysis tasks conducted in support of revisions to the North Santa Monica Bay Coastal Watersheds (NSMBCW) Enhanced Watershed Management Program (EWMP). Aggregated available and relevant data from various sources. Reviewed appropriate water quality objectives and completed comparison of watershed data to applicable objectives to guide the development of water quality priorities. Completed literature review and compilation for source assessment of water quality priorities.

Project Experience

Michael Marson
Senior Scientist I

Professional Experience

Mr. Marson is a Senior Scientist and serves as a database administrator and software developer for LWA. He has extensive experience in the design, development, implementation, and management of databases in Microsoft Access and Oracle. He has over 35 years of computer programming experience in both government and commercial fields.

Upper Santa Clara River Coordinated Integrated Monitoring Program. 2021-Present.

Santa Clarita, CA.

Mr. Marson acts as the data quality assurance officer (QA/QC) of this project. He performs several data checks on the stormwater data that is collected under the Upper Santa Clara River Coordinated Integrated Monitoring Program (USCR CIMP). He has created and implemented an Access database that imports the data through several import queries.

Once in the database, there are custom queries that ensure completeness of the data and QC checks are done on the data in an efficient way, saving hours per event.

Malibu Creek Watershed CIMP Implementation, City of Agoura Hills. 2016-Present.

Malibu Creek Watershed, CA.

Mr. Marson serves as the project manager for this project and ensures the monthly reports, semi-annual reports, and annual reports are all delivered in a timely manner. He oversees sub-contractors and laboratory invoicing, company invoicing, and post-event reporting. He oversees the field crews and laboratory scheduling, bottle delivery and pickups. This includes all elements of the monitoring process, from autosampler installations, event preparation, coordinating with all crews, and paperwork generation. He worked independently to design and implement an MS Access database to house the data currently collected under this contract. It has a user-friendly interface that allows the user to build and run ad-hoc queries of the data. The client could then export the data into a CEDEN compatible Excel file. The database also has the ability to import electronic data deliverable (EDD) files from several different laboratories and many pre-defined queries that are used to quickly run completeness and QA/QC checks of the data. Mr. Marson developed a custom Field Monitoring Preparation Application that the monitoring lead uses to efficiently produce all the monitoring paperwork for the sampling crews. This includes the bottle orders prior to any event and the COCs, bottle labels, and field logs that are used during the events.

Calleguas Creek Watershed (TMDL program), Calleguas Municipal Water District. 2005-Present. Camarillo, CA.

Mr. Marson acts as the project manager for the monitoring activities for the Calleguas Creek Watershed TMDL program. This includes all elements of the monitoring process from database design and upkeep, equipment installation and maintenance, event preparation and paperwork, field crew and laboratory oversight, data quality review, sub-invoicing, and post-event reporting. With the new Ventura County Stormwater Coordinated Integrated Monitoring Program (CIMP) approval, Mr. Marson now coordinates with the County of Ventura stormwater team, the VCAILG program team, and subcontractors to ensure all data covered under all three projects are collected in coordination with each other. He must also coordinate with the labs to ensure samples are picked up/delivered in a timely manner for two dry-weather and two wet-weather monitoring events. Mr. Marson is the sole contact for the field crews in case of any questions that may arise. Mr. Marson uses a separate custom- made Field Monitoring Preparation Application for this project to efficiently produce all the monitoring paperwork for the sampling crews. He manages all of the data that gets Education
B.S., Computer Science,
College of Engineering,
1988,
University of California,
Santa Barbara,
Santa Barbara, CA
Years of Experience
With LWA: 20
With Other Firms: 15
Specialized Tools
VB programming in MS
Access
Additional Training
HP Unix (HPUX-10) Admin
Classes (total 3 weeks),
1997

Siebel Sales Force
Development Classes, 2001

Actuate Report Writer
classes, 2001

Many on-line Computer
Based Training (CBT)
classes offered by Microsoft

Project Experience
generated from these events in a custom MS Access database that he designed and implemented. This ever -growing database houses over 825,000 data records and can import electronic data deliverable (EDD) files from several different laboratories and quickly run completeness and QA/QC checks, saving time during the data quality analysis phase. Mr. Marson also is the lead on the continuous salts sensors that are installed in Calleguas Creek at five different locations. He oversees and collects the monthly salt’s data needed to ensure the sensors are working and calibrated correctly. If a sensor goes bad or has malfunctions, he is the lead repair technician that corrects the issue or replaces the bad sensor.

Ventura County Agricultural Irrigated Lands Group (VCAILG), Farm Bureau of Ventura. 2008 -Present. Ventura, CA.

Mr. Marson acts as the project manager for the monitoring portion of this project. Mr. Marson leads all the monitoring activities for the Ventura County Agriculture Irrigated Lands Group (VCAILG) monitoring program. This project is unique in that two teams of one LWA person and one subcontractor are used to monitor all the sites. Mr. Marson oversees coordinating the subcontractor, LWA employees, and three different laboratories, to ensure samples are picked up and delivered on time, for two wet and two dry monitoring events. He uses a separate custom -built Field Monitoring Preparation Application for this project to efficiently produce all the monitoring paperwork used during the events, including field logs, COCs, bottle labels, and bottle order forms. He manages all the data that gets generated during these events. He has designed, developed, and implemented three different MS Access databases used to store water quality data, membership information, and agricultural Best Management Practices (BMPs) survey results for VCAILG. Each database was designed and developed by LWA to accommodate the needs of VCAILG. The water quality data files continue to grow as we collect more data each year. This database currently houses over 193,000 data records. It can import electronic data deliverable (EDD) files from multiple laboratories and quickly run completeness and QA/QC checks, saving time during data quality analysis. This data is used in establishing trends with constituents in Ventura County and is reported each year to the Regional Control Board during the annual report process. Custom export queries have been created to support the annual monitoring report creation along with a CEDEN export to allow the VCAILG data to be exported then submitted to CEDEN. The membership and BMP results databases have now been replaced with a web-based database where Mr. Marson continues to provide historical support.

Field Monitoring Preparation Application, Multiple Clients. 2008-Present. Ventura, CA Mr. Marson designed, developed, and implemented several user-friendly database applications that significantly reduce field preparation time prior to carrying out a field monitoring event. The “Field Prep” application is/was currently used for several LWA projects, including Malibu CIMP, Mojave River Characterization Study, Calleguas Creek – TMDL and Salts programs, VCAILG – Ag Waiver Program, Malibu Nutrients Special Studies program, and Echo Park Lake Bacteria program. The application produces all the required paperwork for an event, including field logs, bottle labels, bottle orders, field logbook reports, and COC documents for any given monitoring event. Once the required data is input into the application, the user can produce all the materials for the event with a few clicks of a button. Typical errors encountered when creating COCs, bottle labels, field logbooks, etc., are eliminated because all monitoring materials are produced from a single database table. This application is constantly being updated to include new features as needed. It has saved many hours of staff time during monitoring event preparation.

LA River Temperature Study, Los Angeles County. May 2024-October 2024. Los Angeles, CA.

Mr. Marson created a custom Access database to import and house the temperature data collected from HOBO loggers installed in the Los Angeles River (LAR). Temperature data was collected every half hour at 22 stations in the LAR from May 2024 to October 2024. The loggers recorded temperature and if the logger was ‘in’ or ‘out’ of the water, along with location. Once the data file was downloaded from the data logger, it could be imported into the database for processing. The data was then processed to attach an ‘In/Out’ flag to each data row. The data was then exported into a usable format for analysis. This database houses over 150,000 data rows.

Project Experience

Sebastian Bognar
Project Scientist II-A

Professional Experience

Mr. Bognar is a Project Scientist with LWA and has professional experience in water quality monitoring, water quality data analysis, hydrology, and stormwater management. He joined LWA after completing his graduate degree at Duke University. Since joining LWA, he has been involved in water quality analysis, Total Maximum Daily Load (TMDL) compliance, Watershed Management Plan (WMP) and Coordinated Integrated Monitoring Program (CIMP) implementation, and regulatory assistance.

Upper Santa Clara River Watershed Coordinated Integrated Monitoring Program 2021- Present. Santa Clarita, CA.

Task Lead responsible for compiling stormwater program activities, data, and data analysis results to complete the annual report for the Upper Santa Clara River watershed. Work efforts included conducting trend analysis, exceedance analysis, TMDL analyses, and cause-and-contribution analysis of water quality data for the Upper Santa Clara River watershed to address the requirements of the MS4 permit. Task lead responsible for updating the Upper Santa Clara River Watershed CIMP to align with the MS4 Permit requirements. Responsibilities included updating constituents, regulatory language, and monitoring locations to meet the MS4 Permit requirements.

City of Los Angeles Coordinated Integrated Monitoring Program & Annual Reporting . 2019-Present. City of Los Angeles, CA.

Task Lead responsible for compiling stormwater program activities, data, data analysis results to complete annual reports for Ballona Creek, Dominguez channel, Santa Monica Bay Jurisdictions 2 and 3, Santa Monica Bay Jurisdiction 7, and the Upper Los Angel es River. Work efforts included conducting trend analyses, TMDL analyses, and exceedance analyses of water quality data for Ballona Creek, Dominguez Channel, Upper Los Angeles River, and Santa Monica Bay watershed management areas as part of the MS4 permit requirements. Responsibilities also included overseeing staff, reviewing work products, and developing schedules to meet client and regulatory deadlines. Task lead responsible for updating the Ballona Creek, Dominguez channel, Santa Monica Bay Jurisdictions 2 and 3, Santa Monica Bay Jurisdiction 7, and the Upper Los Angeles River Watershed CIMPs to align with the MS4 Permit. Responsibilities included updating constituents and regulatory language, and monitoring locations to meet MS4 Permit requirements.

Upper San Gabriel River Watershed Coordinated Integrated Monitoring Program: As- Needed Consultant Services and Annual Reporting, Los Angeles County. 2020 - Present. Los Angeles County, CA.

Task Lead responsible for compiling stormwater program activities, data, data analysis results to complete the annual report for the Upper San Gabriel River Watershed to address the requirements of the MS4 permit. Task lead responsible for updating the Upper San Gabriel River Watershed CIMP to align with the MS4 Permit requirements. Responsibilities included updating constituents, regulatory language, and monitoring locations to meet the MS4 Permit requirements.

Malibu Creek Watershed Coordinated Integrated Monitoring Program, City of Malibu, CA. 2019-Present. Malibu, CA.

Task Lead responsible for compiling stormwater program activities, data, data analysis results to complete the annual report for the Malibu Creek watershed. Work efforts included conducting the trend analysis, exceedance analysis, TMDL analyses, and cause and Education
M.E.M., Water Resources
Management, 2019, Duke
University, Durham, NC

B.S, Aquatic Biology, 2015,
University of California,
Santa Barbara
Santa Barbara, CA

Years of Experience
With LWA: 5.5
Professional Affiliations
CASQA, Member
Registrations
Certificate of Geospatial
Analysis, Duke University,
NC
2019
Specialized Tools
ArcGIS
R/RStudio

Project Experience
contribution analysis of water quality data for the Malibu Creek watershed to address the requirements of the MS4 permit. Task Lead responsible for updating the Malibu Creek Watershed CIMP to align with the MS4 Permit requirements. Responsibilities included updating constituents, regulatory language, and monitoring locations to meet the MS4 Permit requirements.

City of Los Angeles Regulatory Assessment Support, City of Los Angeles. 2020 -Present. City of Los Angeles, CA.

Task Lead responsible for conducting analyses associated with TMDL compliance, 303(d) listings, Time Schedule Orders (TSOs), Toxicity Reduction Evaluations (TREs), and re-evaluations of waterbody pollutant combinations for various watersheds in the Los Angeles Region. Assisted with additional technical support requests such as permit compliance analyses, alternative TMDL compliance, comment letters, and regulatory assistance.

Street Sweeping Special Study, City of Los Angeles. 2023-Present. City of Los Angeles, CA.

Task Lead responsible for the development of the City of Los Angeles’ Street Sweeping Special Study that is focused on quantifying the effect of street sweeping on removing street dirt and associated pollutants from entering waterways.

Responsibilities included developing the workplan and monitoring plan for the street sweeping study, creating simulated street dirt, and managing controlled street sweeping testing.

Los Angeles River Temperature Study, City of Los Angeles. 2024-Present. City of Los Angeles, CA.

Technical Lead responsible for creating HEC-RAS model for the Burbank Western Channel and associated wastewater outfalls in the Los Angeles River watershed. The HEC-RAS model was used to simulate various flow and temperature scenarios for future BMP and climate-related implementation in the Los Angeles watershed.

Trash Daily Generation Rate Study, City of Los Angeles. 2023. County of Los Angeles, CA.

Task Lead who participated in the trash Daily Generation Rate (DGR) Study to assess compliance with Los Angeles River Watershed Trash Total Maximum Daily Load (TMDL) for areas using partial capture systems and institutional measures. Responsibilities included trash collection and monitoring at ten sites over the eight-week study period, trash characterization, and quantification activities.

Stormwater Program Support, City of Redondo Beach, CA. 2020-2022. Redondo Beach, CA.

Task Lead responsible for the development of website content and public education materials, and other, as needed services to address the requirements of the MS4 permit.

Malibu Creek Watershed Management Group EWMP Update, Los Angeles County, CA. 2020. Los Angeles County, CA.

Technical Task Lead responsible for drafting the source assessment appendix for the Malibu Creek Watershed EWMP Update. Tasks included performing the exceedance analyses, analyzing results from various agencies, reviewing TMDLs, special studies, and scientific literature.

Upper Santa Clara River EWMP Update, City of Santa Clarita, CA. 2021. Santa Clarita, CA.

Technical Task Lead responsible for supporting updates to the Upper Santa Clara River Enhanced Watershed Management Plan (EWMP), including reevaluation of water quality priorities, as required by the 2021 Los Angeles Regional MS4 Permit.

North Santa Monica Bay Coastal Watersheds EWMP Update, City of Malibu, CA. 2021. Malibu, CA.

Technical Task Lead responsible for supporting updates to the North Santa Monica Bay Coastal Watersheds Enhanced Watershed Management Plan (EWMP), including reevaluation of water quality priorities, as required by the 2021 Los Angeles Regional MS4 Permit.

Ventura County Regulatory Support, Ventura County, CA. 2020. Ventura County, CA.

Task Lead responsible for the development of several comment letters for Permittees in Ventura County in response to the Basin Plan Amendment on Final TMDL Implementation Deadline Extensions in the Los Angeles Region.

Aric Torreyson, PE, ENV SP
Project Manager

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Mr. Torreyson has over 24 years of experience in water resources engineering, environmental engineering, and infrastructure assessment and master planning.

He serves as Program Manager for Tetra Tech’s USACE Los Angeles District Design IDIQ contract. His expertise spans surface water hydrology, sediment transport, stormwater runoff, and hydraulic and hydrodynamic modeling.

He has managed numerous large-scale flood control projects involving complex permitting (including UPRR), right-of-way mapping and acquisition, geotechnical engineering, structural analysis, and environmental compliance. Mr. Torreyson has also led multiple Value Engineering studies for the Los Angeles and San Francisco Districts, resulting in significant cost savings. His experience includes delivering multidisciplinary civil works projects from planning through construction, with a focus on resilient and effective flood risk reduction solutions.

TETRA TECH PROJECT EXPERIENCE
Adventure Park and Alondra Park Multi-Benefit Waste Load Allocation (WLA) Analysis, Los Angeles County Department of Public Works, Los Angeles County, CA
Project Manager. Managed the WLA analysis for both park projects to prepare a credit memorandum for Caltrans based on wet and dry weather conditions for the long-term and 85th percentile. The analysis included land use characteristics of the contributing drainage area, Annual average pollutant loading (based on the most recent 10 years of the WMMS model), and 85th percentile 24-hour storm runoff for sediment, nutrients, ts, metals, bacteria, and trash. The analysis was performed for Caltrans and non-Caltrans land uses to determine the contribution level and reduction of these pollutant constituents in combination with the project funding. The Team worked with LACDPW and Caltrans on the modeling and approval of the credit memorandum. Managing the final design services for Los Angeles County Public Works to monitor the baseline flow conditions, optimize the regional system inflow, storage, and outflow, and develop design plans for the 21.5-acre-foot regional stormwater capture facility. The project aims to reduce long-term annual pollutant loading to the Upper San Gabriel River waterways by implementing watershed control measures and structural BMPs while incorporating additional project benefits such as LID measures and sustainable landscaping in the park. The project includes a channel diversion system, a pretreatment unit, underground storage, and a post-treatment filtration unit.

Aliso Creek Mainstem Ecosystem Restoration; USACE, Los Angeles District Design Manager. Managed the design aspect of the multi-disciplinary project; coordinated with USACE to develop various design alternatives and determine a preferred solution. The project included the preparation of a feasibility-level

EDUCATION
BS Civil Engineering, California State
Polytechnic University, Pomona
(2000)

REGISTRATION/CERTIFICATION
Professional Engineer, Civil: CA
License No. 66068
Envision Sustainability Professional
(5/2022)

PROFESSIONAL AFFILIATION
American Society of Civil Engineers
Association of State Dam Safety
Officials
Association of State Floodplain
Managers

YEARS OF EXPERIENCE
25 Years

YEARS WITH TETRA TECH
17 Years

OFFICE LOCATION
Irvine, CA

AREAS OF EXPERTISE
Project Management
Complete Streets
Stormwater Capture/Reuse
Roadway Improvements
Water Quality
Storm Drain Improvements
Utility Relocations
CEQA/NEPA Permitting
Caltrans Permitting
Right-of-Way Acquisition
USACE 408 Permitting

Aric Torreyson, PE, ENV SP

Page 2 ends

design plan, basis of design report, quantity calculations, and cost estimate to improve Aliso Creek between the treatment plant owned by the South Orange County Wastewater Authority (SOCWA) and Pacific Park Drive. The design includes four design alternatives including a no-action plan. Each alternative consists of baseline condition design (channel grading and riffle structures) and multiple design options (addition measures) that can be incorporated into the alternative formulation. The design would provide channel stability and aquatic connectivity for selected species within the project limits. Tetra Tech has been selected to continue the next phase of the project which involves further development of the USACE’s preferred alternative.

City Of Anaheim NPDES Compliance Support Services, City of Anaheim, Anaheim, CA Principal. The project, commissioned by the City of Anaheim, aimed to model the storm drain system for District 27 as part of the master drainage plan for the North and South Santa Ana River Tributary Area. The project was executed by Tetra Tech, who refined the modeling efforts from FY22-23 to identify and address deficiencies within District 27.

The project was divided into five tasks:

1. District 27 Drainage Study: This involved revising hydrology as per Orange County standards, updating H&H to include BMPs within the watershed, preparing an H&H report, and creating concept drawings to address existing deficiencies. The goal was to provide a hydrology analysis conforming to the Orange County Hydrology Manual for potential future submittals requiring Orange County Public Works approval.

2. Revised Hydrology Per Orange County Standards: Tetra Tech coordinated with Orange County to discuss the methodology for this project. They developed site hydrology using the rational method to calculate peak flow rates tributary to and conveyed in the State College Storm Drain, County E12 Facility, and ultimately discharging to the Santa Ana River.

3. Update H&H to include BMPs within the Watershed: The existing hydrology was refined to include existing and possible proposed BMPs within the watershed. Unit hydrographs were adjusted to account for any flow diversion to BMPs.

4. Prepare H&H Report: A report was prepared summarizing findings from updated hydrology and hydraulic findings.

5. Prepare Concept Drawings: Alternatives for diverting flow from the pipe network were determined to reduce flow to the County E12 Facility.

The project also included management tasks such as providing bi-weekly project updates to the city and facilitating coordination with OCPW and other agencies as necessary.

Sunset Crossing Park Feasibility Study, County of Los Angeles Department of Public Works, Alhambra, CA Project Manager, Senior Engineer. Currently managing the feasibility for the Sunset Crossing Multi-Benefit Storm Water Capture Feasibility Study. The project is adjacent to Diamond Bar Channel, which drains to San Jose Creek South Fork, San Jose Creek, and ultimately to the San Gabriel River. San Jose Creek is impaired by ammonia, bacteria, pH, TSS, and toxicity. San Gabriel River is also impaired and is under TMDLs for metals and selenium. The project is an important component in treating drainage consisting of approximately 1625 acres of industrial, commercial, and residential development for zinc and bacteria. In addition to treating stormwater, the project will provide critical park space to the residents of Diamond Bar and the surrounding DAC directly adjacent to the site. Tetra Tech is responsible for the H&H, water quality analysis, conceptual design, environmental review, community outreach, and landscape architecture.

Timothy P. Tringali, CPESC, QISP, QSD/P
Project Manager/Senior Environmental Scientist

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Mr. Tim Tringali is a Senior Environmental Scientist and Project Manager with more than 21 years of experience assisting federal, state, and local entities develop, implement and manage a variety of water resource programs. Much of his experience includes management of multi-disciplined teams and execution of storm water management and compliance programs for the U.S. Air Force, municipalities, coastal ports, and private industry. Mr. Tringali has a strong understanding of the Clean Water Act, as well related federal and state adopted regulations.

Mr. Tringali’s experience includes assisting clients identify waters protected under the CWA; interpret water quality standards; apply for and comply with National Pollutant Discharge Elimination System permits; and comply with national and local wastewater pretreatment regulations. Mr. Tringali also has a broad understanding of the California Environmental Quality Act (CEQA) and National Environmental Policy Act (NEPA). Mr. Tringali’s noteworthy technical accomplishments include: previously serving as a U.S. EPA contract inspector for California-Wide Phase I Municipal and Industrial Storm Water Audits; managing NPDES compliance for Aera Energy, LLC, which produces oil and gas across a 4,000 acre lease in Ventura County; managing monitoring and assessment programs across San Diego and LA County pursuant to complex regional MS4 Permits; aiding private and municipal clients strategize solutions to complying with the increasingly complex Industrial General Permit; and managing the Central Coast Cooperative Monitoring Program, which is a large surface water quality monitoring program that fulfills grower requirements enrolled in a regional waiver of Waste Discharge Requirements for Discharges from Irrigated Lands.

TETRA TECH PROJECT EXPERIENCE
City of Santa Clarita, Coordinated Integrated Monitoring Program (CIMP) for the Upper Santa Clara River (USCR) Watershed, 2015–Present. As Project Manager, Mr. Tringali leads a team of technicians, scientists, and engineers to implement the USCR CIMP on behalf of the USCR Watershed Management Group (i.e., the City of Santa Clarita, the County of Los Angeles, and the Los Angeles County Flood Control District). The USCR CIMP monitoring locations consist of both receiving water and outfall monitoring locations, which are sampled during both dry and wet weather conditions. Monitoring satisfies LA Regional MS4 Permit requirements, including compliance and reporting for TMDLs related to bacteria, nitrogen, chloride, and trash. USCR CIMP reporting includes data analysis and development of regular post-event monitoring reports, semi-annual reports using specified CEDEN templates, and Annual Reports according to Los Angeles RWQCB templates. Mr. Tringali frequently supports discussions related to TMDL attainment.

City of Malibu, Coordinated Integrated Monitoring Program (CIMP) for the North Santa Monica Bay Coastal Watersheds (NSMBCW), 2016 –Present. As Project Manager, Mr. Tringali leads a team of technicians, scientists, and engineers to

EDUCATION
B.S., Ecology and Systematic Biology,
California Polytechnic State
University, 2001

REGISTRATION/CERTIFICATION
Cert. Professional in Erosion and
Sediment Control (#5929)
CA Qualified SWPPP
Developer/Practitioner
CA Qualified Industrial SWPPP
Practitioner (QISP)
HAZWOPER –40-hour w/ current 8-
hour refresher
Water Quality Monitoring Design, UC
Berkeley (2012)
NEPA (2020)

PROFESSIONAL AFFILIATION
California Storm Water Quality
Association
Society of American Military
Engineers 1430 (1987)

YEARS OF EXPERIENCE
23 Years

YEARS WITH TETRA TECH
22 Years

OFFICE LOCATION
Santa Maria, California

AREAS OF EXPERTISE
Stormwater permitting, compliance,
planning, and monitoring
TMDL planning and implementation
Surface water monitoring
Water quality assessment
Wastewater discharge permitting,
compliance, and pretreatment
Erosion/ sediment control
BMP selection/evaluation
NEPA
Timothy P. Tringali, CPESC, QISP, QSD/P

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implement the NSMBCW CIMP on behalf of the NSMBCW Watershed Management Group (i.e., the City of Malibu, the County of Los Angeles, and the Los Angeles County Flood Control District). The NSMBCW CIMP monitoring locations consist of both receiving water and outfall monitoring locations, which are sampled during both dry and wet weather conditions. Monitoring satisfies LA Regional MS4 Permit requirements, including compliance with adopted TMDLs for bacteria, PCBs/DDT, and trash. NSMBCW CIMP reporting includes data analysis and development of regular post-event monitoring reports, TMDL reporting, semi-annual reports using specified CEDEN templates, and Annual Reports according to Los Angeles RWQCB templates. Mr. Tringali frequently supports discussions related to TMDL attainment. 5-year Progress Review & Adaptive Management Recommendations for Middle Santa Margarita River, Riverside County Flood Control District, Riverside County, CA, 2024. Mr. Tringali led a progress review and assessment of Riverside County Copermittees' Water Quality Improvement Plan (WQIP) implementation efforts for the 2018-2023 period. He managed scientists and engineers evaluate dry weather flow and nutrient loading trends at-source, in-stream, and delivered to the Santa Margarita River and Estuary. He also contributed to Tetra Tech’s assessment of Riverside County Copermittees compliance with WQIP requirements, progress to goals outlined in the WQIP, and strategy implementation effectiveness based on this data. Finally, Mr. Tringali led a review of the Riverside County Copermittees’ strategy for achieving the proposed TMDLs for the River and Estuary including numeric targets, and the reduction in pollutant loadings necessary to restore beneficial uses of the Estuary.

Upper Los Angeles River Bacteria Load Reduction Strategy Adaptation Human Waste Source Investigations, 2021- 2025. Mr. Tringali is leading human waste source investigations across multiple “areas of investigation” within the Upper Los Angeles River watershed. Human waste source investigations comprise planning and implementation of multi-day, synoptic sampling events to characterize E. coli and HF183 (a human-associated biomarker that can be used for microbial source tracking) in the receiving water, at outfalls, and within outfall catchments. Due to very short method hold-times and a limited number of commercial labs capable of analyzing for HF183, samples are field-filtered and placed on dry ice which significantly extends the hold-time of the filters for subsequent analysis. Results are validated and regularly presented to a Technical Advisory Committee, which ‘steers’ the direction of the human waste source investigations.

Upper Los Angeles River (ULAR) Bacteria Load Reduction Strategy (LRS) Adaptation, 2020-2021. The ULAR LRS was developed to guide the ULAR Watershed Management Group’s efforts to address the Los Angeles River Bacteria TMDL.

However, to address the challenges encountered during implementation of the original LRS, it was adapted towards a more efficient and effective strategy that relies on targeting controllable, human fecal sources. Mr. Tringali assisted with the update of the ULAR LRS, specifically as it related to incorporation of scientific advancements that better address methods for characterizing human-health risk based on the source of bacteria in a receiving water. Mr. Tringali collaborated with a team of engineers and scientists to define a framework and methods for performing human waste source investigations based on predicted risk of outfall catchments. A primary tool proposed in the ULAR LRS Adaptation Plan was sampling and analysis for HF183, a human-associated biomarker that can be used for microbial source tracking.

Quincy Jones and Central Jefferson BMP Effectiveness Monitoring Plans and Implementation, 2020-Present. Mr.

Tringali was the Principal Scientist for development of a Sampling and Analysis Plan and Quality Assurance Program Plan which describes the approach to evaluating performance of two recently constructed green alleys. The plans describe methods for characterizing untreated and treated pollutant loading; therefore, a combination of flow and water quality sensors will be used. Monitoring according to the plans will begin mid-2023.

Marine Terminal Stormwater Monitoring Program, San Diego Unified Port District, San Diego, CA, 2019-2023. In response to a Settlement Agreement, Mr. Tringali led development and implementation of a strategic stormwater monitoring program, which was intended to assess the effectiveness of the Port’s Stormwater Management Program according to effectiveness requirements of the San Diego Water Board’s Regional MS4 Permit. The monitoring plan developed by Mr. Tringali and supporting staff included multiple sample collection methods (grab, composite, pollutographs) to address a range of objectives.

Lauro Alvarado, EIT
Water Resources Engineer

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Lauro Alvarado is a water resources engineer with experience in construction oversight, stormwater sampling, and database management. He has been involved in various significant projects, including the implementation of the NSMBCW CIMP and the USCR CIMP, where he prepared field equipment, organized sample bottles, and collected stormwater samples. Lauro has also contributed to the preparation of detailed reports and technical memoranda, ensuring compliance with regulatory requirements. His expertise includes using ArcMap for flood control work and updating inventories, as well as providing data review and reporting services.

TETRA TECH PROJECT EXPERIENCE
Upper Santa Clara River Coordinated Integrated Monitoring Program, City of Santa Clarita, CA (2021-2024)
Water Resources Engineer. Work has included preparing field equipment before stormwater sampling, labeling and organizing sample bottles, and going out into the field for collection of stormwater samples and measurement of water quality characteristics as well as documentation of observations. General staff coordination and project management. Also provided data review and reporting.

Upper Los Angeles River CIMP, City of Los Angeles, Los Angeles, CA (2020 - Ongoing)
Stormwater Monitoring. Work has included preparing field equipment before stormwater sampling, labeling and organizing sample bottles, and going out into the field for collection of stormwater samples and measurement of water quality characteristics. Data review, reporting.

Coordinated Integrated Monitoring Program (CIMP) for the North Santa Monica Bay Coastal Watersheds (NSMBCW), City of Malibu, Malibu, CA (2020 -Ongoing) Database Management. Implementation of the NSMBCW CIMP on behalf of the NSMBCW Watershed Management Group (i.e., the City of Malibu, the County of Los Angeles, and the Los Angeles County Flood Control District). The NSMBCW CIMP monitoring locations consist of both receiving water and outfall monitoring locations, which are sampled during both dry and wet weather conditions.

Monitoring satisfies Los Angeles Regional MS4 Permit requirements, including compliance with adopted TMDLs for bacteria, PCBs/DDT, and trash. Work has included preparing field equipment before stormwater sampling, labeling and organizing sample bottles, and going out into the field for collection of stormwater samples and measurement of water quality characteristics. Data review, reporting.

EDUCATION
BS Civil Engineering, University of
California, Los Angeles (2019)

REGISTRATION/CERTIFICATION
Engineer-in-Training: CA License No.
168933 (2019)

PROFESSIONAL AFFILIATION
American Society of Civil Engineers

YEARS OF EXPERIENCE
5 Years

YEARS WITH TETRA TECH
5 Years

OFFICE LOCATION
Pasadena, CA

AREAS OF EXPERTISE
Construction Oversight
Stormwater Sampling
Database Management
Technical Reporting
GIS and ArcMap
Monitoring
Fieldwork
Data Review

Lauro Alvarado, EIT

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Coordinated Integrated Monitoring Program (CIMP) for the Upper Santa Clara River (USCR) Watershed, City of Santa Clarita, Santa Clarita, CA (2020-Ongoing)
Database Management. Involved in the implementation of the USCR CIMP on behalf of the USCR Watershed Management Group, which includes the City of Santa Clarita, the County of Los Angeles, and the Los Angeles County Flood Control District. The monitoring locations for the USCR CIMP consist of both receiving water and outfall sites, sampled during both dry and wet weather conditions. This monitoring satisfies the Los Angeles Regional MS4 Permit requirements, including compliance with adopted TMDLs for bacteria, nitrogen, chloride, and trash. His work has involved preparing field equipment before stormwater sampling, labeling and organizing sample bottles, and going out into the field to collect stormwater samples and measure water quality characteristics. Addi tionally, he has provided data review and reporting.

Culver Boulevard Stormwater Infiltration and Retention. The City of Culver City, CA (2018-2021) Water Resources Engineer. Prepared the QAPP for this project including addressing comments from the client.

Specialized Services for CIMP Data Generation, Automated Monitoring Stations, City of Los Angeles, CA (2020 - Ongoing)
Construction Oversight. Installation of automated monitoring stations for the City. Provided construction oversight that included photographing work, being on-site during construction, attending pre-construction meetings, and filling out daily work logs.

Jack Weil
Environmental Scientist

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Mr. Jack Weil is an environmental scientist with a wide range of experience in data analysis, GIS mapping, environmental regulatory compliance, field monitoring and sampling, sustainability, and stakeholder outreach. His expertise in collecting and analyzing environmental data and his experience within public regulatory environments make him highly knowledgeable in many different areas of environmental compliance. His educational background in earth sciences and engineering showcases the breadth of his expertise and ability to apply a range of knowledge and experience to complex problems. Jack has provided expertise for environmental monitoring efforts, commercial and industrial stormwater compliance, bacteria load reduction assessment, and GIS mapping.

TETRA TECH PROJECT EXPERIENCE
Upper Santa Clara River Coordinated Integrated Monitoring Program (CIMP), City of Santa Clarita, CA (2023)
Conducted stormwater outfall field sampling during dry weather to monitor pollution levels in the Upper Santa Clara River through their Coordinated Integrated Monitoring Program. Organized and logged field samples and completed Chain of Custody forms for delivery to lab facilities.

Marine Terminal Stormwater Monitoring, Port of San Diego, CA (2022-2023) Conducted stormwater field sampling during storm events to monitor pollution levels before and after treatment by stormwater BMP facilities. Organized and logged field samples and completed Chain of Custody forms for delivery to lab facilities.

Outfall Drainage Field Surveys, County of San Diego Department of Public Works (2023-present)
Project Manager. Led team to conduct field investigations for the County of San Diego outfall monitoring program. Coordinating drainage area investigations for identification and reporting of residential over-irrigation. Creating and sending educational outreach letters as well as inspection reports for residences where over-irrigation is detected. Developed field procedures and health and safety plans for the field team and coordinated the development of field driving routes.

Analyzing data, conducting quality assurance reviews, and developing data summaries for the County.

Santa Margarita River (SMR) 5-Year Water Quality Improvement Plan (WQIP) Progress Review, Riverside County Flood Control and Water Conservation District (2023-present)
Environmental Scientist. Reviewing water quality data and modeling methodologies for the SMR to conduct a 5-year progress review for the Riverside County MS4 Permit Copermittees to show progress toward goals for nutrient reduction within the Middle SMR subwatershed. Providing water quality

EDUCATION
MS Earth Sciences, University of
California, San Diego (2022)
BS Civil Engineering, Loyola
Marymount University (2019)

PROFESSIONAL AFFILIATION
California Stormwater Quality
Association (CASQA)
Tao Beta Pi Engineering Honor
Society

YEARS OF EXPERIENCE
5 Years

YEARS WITH TETRA TECH
1 Years

OFFICE LOCATION
San Diego, CA

AREAS OF EXPERTISE
GIS Mapping
Data Processing and Analysis
Stormwater Pollution Prevention and
Regulatory Compliance
Field Monitoring and Sampling –
Stormwater, Soil, Groundwater, and
Surface Water
Stakeholder Outreach
Environmental Compliance
Sustainability Practice
Implementation
Jack Weil

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recommendations and nutrient modeling updates based on a review of data. Conducted MS4 Permit and WQIP review to establish regulatory context for the 5-year review; reviewed existing water quality data from 2018-2022 and determined progress evaluation approach for 6 compliance pathways outlined by the 2018 SMR WQIP.

Existing Structural BMP Verification for Trash Devices, County of San Diego Department of Public Works, San Diego, CA (6/2024-8/2024)
Project Manager. Managed project supporting the County of San Diego with inspections and verifications of stormwater structural BMPs and determination of device trash capture capacities. Led field team in conducting inspections, developed health and safety plans, and assessed device condition and recommended maintenance. Communicated with device manufacturers and the CA Water Board to obtain information needed in trash capture equivalency research. Conducted hydraulic analyses to determine maximum flow to each device from a 1-yr, 1-hr storm event (as required by the 2015 Trash Amendments). Calculated BMP device treatment capacity from in-field measurements to determine trash capture equivalency. Analyzed data, conducted quality assurance reviews, and developed final summary spreadsheets for the client. The project supported the County’s goals of maintaining compliance with state regulations and MS4 Permit requirements. Although the Trash Amendments have yet to be incorporated into the San Diego Regional MS4 Permit, this project ensures that the County is prepared for conversations relating to full trash capture in the future. It also ensures that there is adequate documentation about the type, condition, and trash capture status for all BMPs that were part of this project.

Rainbow Creek TMDL/TSO Support, City of San Diego, CA (2023-2024) Project Manager. Reviewed and summarized regional regulatory documents and previous Rainbow Creek studies.

Created a report inventory listing and summarizing previous Rainbow Creek studies. Created an Executive Summary document outlining relevant information about the watershed and previous work completed. Reviewed management briefing sheets related to Rainbow Creek and the Santa Margarita River. A significant challenge was piecing together a wide range of information related to the watershed. Many different studies had been performed with different project teams, so information had to be gleaned after the fact through a review of previous reports. The solution to this was to create an Executive Summary for the watershed so that all previous work could be synthesized into an easy-to- understand document. This solution benefited the client by saving time for future team members; anyone doing work in the watershed can review the Executive Summary to get up to speed on the work previously completed. The project supported the client’s ability to communicate with the Regional Water Board about the Rainbow Creek TMDL and TSO.

No additional tasks. The project was completed on schedule and within budget.

Virginia Beach Bacterial TMDL Strategy, City of Virginia Beach, VA (2023-Ongoing) Data processing and analysis and GIS mapping support for an assessment of the City of Virginia Beach’s bacteria reduction strategy. Gathered available water quality data to conduct a bacteria threshold exceedance assessment to determine the effectiveness of bacteria reduction strategies within the City. Providing support in identifying gaps in existing data collection and providing recommendations on improvements to better assess the City’s reduction strategies. Also creating GIS maps and figures to visualize these assessments.

Asset Management GIS Support, City of San Diego, CA (2022- Ongoing) Supporting GIS digitization of City of San Diego stormwater assets. Reviewed construction As-Builts and identified installation and removal of stormwater assets to update the City GIS database. Performed georeferencing of construction As-Builts to identify stormwater asset locations within the City GIS database. Also performing confirmation of existing database assets through As-Built review, online street view and aerial imagery, and field investigations.

Gary G. Wortham
Senior Environmental Scientist/Aquatic Toxicologist

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Mr. Wortham has more than 30 years of experience in the environmental sciences, with expertise in stormwater, surface water and sediment quality analytical and field sampling methodologies and project design as well as project QA/QC; QAPP development; Health and Safety Plan (HASP) development and implementation; sampling plan development and implementation and data interpretation; analytical chemical laboratory management; project design; aquatic system data analyses; federal and state water quality regulations; field monitoring (including training field staff on the proper application of the USEPAs ultra-clean sampling method for low-level mercury and water, sediment and habitat assessments) and marine and freshwater systems aquatic toxicity methods development.

Mr. Wortham has developed project-specific Health and Safety Plans (HASPs) for Chevron, Stringfellow and various other internal and external projects as well as lead the field sampling, QA/QC and health and safety components of several projects including the California Ocean Plan Compliance study at Pillar Point AFS, Central Coast Monitoring Program, Torres-Martinez Cahuilla Desert Indians CWA106 and Salton Sea Wetlands Water Quality Plan implementation, Shallow Habitat management of a wetlands adjacent to the Salton Sea, CA, the New and Alamo River Wetlands Salton Sea selenium assessment projects, Pillar Point Air Force Station COP compliance, Central Coast Cooperative Monitoring Program, San Francisco Bay Selenium Study, San Francisco Bay Tributary Mercury Study (assisting Regional Water Board 2 staff); City of San Diego Storm Drain Characterization; Guadalupe River Mercury TMDL, the City of San Jose Streamflow Augmentation, the Calaveras River Watershed Baseline study, the Monterey Harbor Sediment Lead study, the Eureka Waterfront ERA, and has provided QA/QC review.

TETRA TECH PROJECT EXPERIENCE
Upper Santa Clara River Watershed Management Group Coordinated Integrated Monitoring Program, City of Santa Clarita and the County of Los Angeles, CA.

Managed QA/QC assessments of the field and data components of this project, data validation of CEDEN semi-annual and annual EDDs, and preparation of summary QA/QC reports. On behalf of the City of Santa Clarita and the County of Los Angeles, and according to a Coordinated Integrated Monitoring Program, Tetra Tech is conducting receiving water monitoring at two sites, stormwater outfall monitoring at seven sites, and non-stormwater outfall monitoring at nine sites in the Santa Clara River Watershed. In addition, Tetra Tech is conducting a special study monitoring fecal indicator bacteria at select stormwater outfalls and receiving water locations.

North Santa Monica Bay Coastal Watersheds Coordinated Integrated Monitoring Program, City of Malibu and County of Los Angeles, CA. Managed QA/QC assessments of the field and data components of this project, data validation of CEDEN semi-annual and annual EDDs, and preparation of summary QA/QC

EDUCATION
B.S., Oceanography, California State
University Humboldt, 1987

REGISTRATION/CERTIFICATION
40 Hour HAZWOPER
[29 CFR 1910.1209(e)].

First Aid/CPR
Active Shooter Response Training

YEARS OF EXPERIENCE
34 Years

YEARS WITH TETRA TECH
26 Years

OFFICE LOCATION
Lafayette, CA

AREAS OF EXPERTISE
Stormwater, surface water and
sediment quality
Data QA/QC Assessments
Ultra-clean sampling techniques for
low-level metals
Health & Safety

Gary G. Wortham

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reports. On behalf of the City of Malibu and the County of Los Angeles, and according to a Coordinated Integrated Monitoring Program, Tetra Tech is conducting stormwater outfall monitoring at two sites and receiving water monitoring at three sites in the North Santa Monica Bay Coastal Watersheds.

Central Coast Cooperative Monitoring Program. Field and QA/QC Lead; Health and Safety Plan consultant. The overall goals of the monitoring are to characterize the water quality conditions in watersheds from the Pajaro hydrologic unit in the north to the South Coast hydrologic unit near Santa Barbara, to understand long-term water quality trends in agricultural areas, and to meet the requirements specified in the Monitoring and Reporting Program (MRP) for the Conditional Waiver. Water and sediment quality samples are collected during both dry weather and stormwater discharge events. An annual report is prepared, and electronic data deliverables are uploaded to CEDEN every quarter.

Trace metal sampling is conducted using EPA ultra-clean methodologies. Mr. Wortham assisted the project manager in preparing the project-specific health and safety plan and provided review/comment on said document.

North San Francisco Bay Selenium TMDL. Field and QA/QC Lead. Selenium has been a concern in the Central Valley and San Francisco Bay for several decades, a region with selenium sources from San Joaquin Valley and various point sources including refineries. A TMDL project is underway to address selenium toxicity in N orth San Francisco Bay led by the San Francisco Bay Regional Board. With funding provided by WSPA, Tetra Tech is providing technical support to the Regional Board for the development of the TMDL. Mr. Wortham is the field lead and primary QA/QC analyst for this multi-year project which includes sample collection from the Golden Gate Bridge to the Sacramento Valley and from several of the major tributaries to the North San Francisco Bay. Trace metal sampling was conducted using EPA ultra- clean methodologies.

Technical Support to the Torres-Martinez Desert Cahuilla Indians (TMDCI) Constructed Wetlands (Salton Sea, CA).

Project Manager, QA/QC Manager. Developed an EPA-approved Quality Assurance Project Plan for the Tribe and provided ongoing technical support to the TMDCI in implementing their Water Quality Plan for the constructed wetlands on the Reservation. The purpose of the Torres Martinez Constructed Wetlands Project is to study how wetlands can improve the quality of Whitewater River water inflows to the Salton Sea by reducing or removing selenium, nutrient, and bacterial loads into the Sea. To achieve this goal, the inflow and outflow of the Torres Martinez wetlands are monitored regularly to determine the effectiveness of the design to improve water quality by removing nutrients, sediment, selenium, and other contaminants.

Ecological Assessment of Gas and Oil Production Activities in the Central Gulf of Thailand, Chevron Thailand Exploration and Production, Bangkok. Mr. Wortham has been the project health and safety officer since 2000. Mr. Wortham’s responsibilities have included the development, updating, and implementation of the project -specific health and safety plan (HASP) for the development and implementation of survey program designs, interpretation of benthic community data, evaluation of bioaccumulation of mercury and arsenic in benthic invertebrates and fishes, and evaluation of risks to marine environment. Additionally, Mr. Wortham is responsible for data QAQC review. This ongoing project addresses concerns for potential environmental and human health risks due to levels of mercury and arsenic in sediments and fish around offshore processing platforms due to the release of mercury in produced waters. The sampling program includes sampling of sediments, surface water, benthic invertebrates, plankton, and fish to eval uate mercury cycling and estimate human health risks due to the consumption of fish caught from the platforms. Other studies addressed spatial and temporal community-level effects of petroleum hydrocarbons on benthic infaunal communities at wellhead platforms. In addition, Mr. Wortham has included COVID-19 health and safety procedures that are compliant with the U.S. Centers for Disease Control (CDC).

Santa Clarita City CouncilJune 23, 2026

Santa Clarita City Council
June 23, 2026