Currents 2025 Vol 1: PNW's Largest Water Conveyance Project

CAROLLO ENGINEERS VOLUME 1 2025

Building the

Paciﬁc Northwest’s

LARGEST WATER

CONVEYANCE

PROJECT

PLUS 

Recognizing Sustainable

Infrastructure Through Envision®

Stormwater Funding

Success Stories

A Milestone in Securing LA’s

Recycled Water Future

Water ARC®’s

Full-Service Solutions

EDITORIAL

CONTENT EDITOR

Diana Leonard / dmleonard@carollo.com

COPY EDITOR

Mary Ann Mavrogianes

GRAPHIC DESIGNER

Silvia Higuera-Backlund

CURRENTS / IN THIS ISSUE

DIANA LEONARD (dmleonard@carollo.com)

This quarter, our feature story offers a

look into the construction of a pivotal

project that will enhance water quality,

safety, and reliability in Oregon’s

Willamette Valley. We detail how the

Willamette Water Supply System, a

$1.6 billion infrastructure investment,

will be one of the most seismically resilient water

systems in Oregon. We also bring you insights into the

Envision® certification system to help you navigate this

important sustainability framework, and we highlight

proven strategies to qualify for stormwater project

grants and loans in an increasingly competitive

funding environment.

Our article on the DC Tillman advanced water

purification facility showcases how a cutting-edge

indirect potable reuse facility is helping to advance

Los Angeles’ long-term water recycling goals. And

finally, we take a deep dive into Carollo’s Water ARC®

and demonstrate how three specialized programs

work in tandem to craft innovative water solutions

for our clients.

We hope this issue both informs and inspires you.

As always, we welcome your questions and

comments. Please reach out to me or our authors

with your thoughts!

IN THIS ISSUE

Recognizing Sustainable Infrastructure Through Envision®

Stormwater Funding Success Stories

Building the Pacific Northwest’s Largest Water

Conveyance Project

A Milestone in Securing LA’s Recycled Water Future

Water ARC®’s Full-Service Solutions

Sarasota County, Florida, faced a critical

environmental challenge: algal blooms and their

potential to impact the region’s economic vitality,

environmental health, and public safety. To combat

the nutrient discharge causing these blooms, address

reclaimed water storage needs during the wet

season, and accommodate a growing population,

Sarasota County decided to expand the Bee Ridge

Water Reclamation Facility from 12 mgd to 18 mgd.

The project focused on three key goals: enhanced

water quality, a sustainable water supply, and

resilience against climate change.

Sarasota County teamed with Carollo to evaluate

and design the expanded plant. Converting Bee

Ridge to an advanced wastewater treatment facility

significantly improved water quality by reducing

effluent nitrogen and phosphorus levels.

The project earned an Envision

Gold award based

on its excellence in several key areas.

� Environmental stewardship. Protecting

local water bodies and the ecosystem

through the rehabilitation of on-site wetlands

and the reduction of nutrient discharges.

� Climate resilience. Combatting increased

storm intensity and sea-level rise through

design features such as setting finished floor

elevations for new facilities above the 100-year

flood elevation and installing a new electrical

distribution system to supply continuous power.

� Resource efficiency. Conserving limited

resources by implementing robust water reuse

systems and beneficial use of construction waste.

� Community benefits. Supporting population

growth and economic development through

continuous community engagement and

increased reclaimed water availability.

ENVISION

IN ACTION

Sarasota County

Earns the Gold

ENVISION

Enter Envision

Envision® is a sustainability rating system specifically

designed for infrastructure projects, developed by

the Institute for Sustainable Infrastructure (ISI) in

partnership with Harvard University’s Zofnass Program

for Sustainable Infrastructure. Envision® provides

a structured approach to incorporate sustainability

throughout a facility’s lifecycle—from planning

and design through construction, operation, and

maintenance. Think of it as the infrastructure

equivalent of LEED certification for buildings.

How Envision

Works

Projects are evaluated across five key categories:

� Quality of Life. Community wellbeing

and engagement.

� Leadership. Commitment to

sustainability principles.

� Resource Allocation. Material, energy,

and water efficiency.

� Natural World. Ecosystem preservation

and enhancement.

� Climate and Resilience. Emissions

reduction and adaptation capabilities.

Sarasota County’s

Bee Ridge Water

Reclamation Facility

received Envision

’s

second-highest

honor in 2024.

UNDERSTANDING

KATHLEEN MANNION, PE (kmannion@carollo.com)

Sustainable planning and design require holistic

consideration of economic, environmental, and

social factors. While this integrated approach seems

straightforward in concept, actually implementing

sustainable practices in infrastructure projects can

be challenging. Project teams often struggle with

quantifying sustainability efforts, determining priorities,

and creating consistent evaluation frameworks.

COMMENTARY / CURRENTS

ENVISION

Understanding the Rating System

The rating system uses a point-based approach

where projects earn credits in each category through

documented sustainable practices. Each credit has

specific achievement levels (Improved, Enhanced,

Superior, Conserving, and Restorative) that determine the

points awarded.

The total points accumulated across all categories

determine the final certification level. Based on

performance, projects can achieve four certification

levels: Verified, Silver, Gold, or Platinum.

Navigating the Process

Envision certification follows a two-step process:

1. Initial Assessment. Project teams evaluate

performance across all 64 credits, identifying

sustainability opportunities early when they can be

most effectively incorporated into design.

2. Verification Pursuit. For projects with

promising scores, teams submit documentation to

ISI for independent third-party review to confirm

achievement levels.

Certified Envision® Sustainability Professionals (ENV SPs)

guide the assessment process, helping facilities work

toward the highest standards while balancing economic,

social, and environmental considerations.

Even without pursuing full verification, the initial

assessment alone provides valuable insights that can

improve project outcomes and sustainability performance.

To date, 396 Envision® projects with a cumulative value of

more than $283 billion have been registered, are under

review, or have been completed. For projects to qualify

for an Envision® award, at least one member of the project

team must have an ENV SP credential.

A Framework

for Resilient and

Sustainable Infrastructure

ENVISION

As stormwater infrastructure ages and replacement

costs rise, utility managers face increasing challenges

in developing viable replacement and upgrade programs.

Federal, state, and local grant and low-interest loan

programs offer alternative funding mechanisms for

critical infrastructure projects; however, growing

needs and limited resources make these programs

highly competitive.

THE FIRST STEP IN APPLYING

FOR FUNDING: KNOW WHAT TO LOOK FOR

Understanding program requirements is the foundation

for developing a competitive application. Some programs

target characteristics specific to the community or project,

such as socially-vulnerable populations or areas with

minimal greenspace. Knowing what to look for when

reviewing a funding application is critical. Success relies

on the applicant’s ability to discern and clearly address

a program’s targets and goals.

Key words in the program requirements can dictate the

application’s structure. Phrases such as environmental

benefits, increased resiliency, or nonpoint source

pollution reduction provide strong direction for the

most vital concerns to address. Utilities can also

modify the proposed project itself to increase funding

competitiveness. This approach requires carefully

reviewing program priorities and adapting designs

accordingly. For example, if the funding program

mentions nature-based solutions, adding rain gardens

can further align a project to the program’s goals. When

programs prioritize resilience in socially-vulnerable

areas, infrastructure can be upsized to demonstrate

added protection where it’s needed.

City of Mount Vernon, Ohio

To mitigate severe bank erosion, flooding, and nonpoint

source pollution affecting stream habitat, historic buildings,

businesses, and roadways along the scenic Kokosing

River, the City of Mount Vernon applied for and received

grant funding for a critical river restoration project. Funding

sources included the Ohio Environmental Protection

Agency’s 319(h) Nonpoint Source Pollution Program and

the local Muskingum Watershed Conservancy District.

The project would not have been feasible without

$500,000 in federal and local grant funding, as Mount

Vernon’s stormwater utility can only support one major

improvement project each year. The city’s applications

featured nature-based solutions—such as riverbank

protection using native plantings—and green and grey

infrastructure. These features closely aligned with the

funding program’s goals.

Completed in 2021, the Kokosing River Restoration

Project has significantly reduced nonpoint source

pollution, decreased erosion, mitigated flooding impacts,

and helped establish a robust habitat for a thriving

population of native freshwater mussels.

SUCCESS

STORIES

The following examples showcase how utilities have secured competitive

funding for critical stormwater projects. Each demonstrates different

strategies—from project modifications to persistent reapplication—that

turned ambitious infrastructure plans into funded projects.

$500

THOUSAND

in federal and

local grant

funding

Mount Vernon’s successful river restoration

funding strategies included nature-based

solutions for erosion control along the banks

of the Kokosing River.

CAROLINE BURGER, PE (cburger@carollo.com)

EMILY PLATT

for Stormwater Infrastructure

FUNDING STRATEGIES

CURRENTS / PROJECT UPDATE

City of Madison, Wisconsin

City of Los Angeles, California

Careful recrafting of Madison’s previously-denied

FEMA BRIC grant application resulted in funding for a

regional flood management project to help prevent

future occurrence of the devastating flood damage

experienced in 2018.

MILLION

in FEMA BRIC

grant funding

$186.9

MILLION

from the

SCW program

Key to LASAN’s success is their extensive community

outreach for these projects. The grant applications

highlight the planned activities and incorporate

language that supports the grant program’s priorities.

Flooding devastated the west side of Madison in August

2018. One area particularly hard hit was the Old Sauk

Trails Business Park, which hosts daycare centers, health

care clinics, and some residential housing. The city’s

Watershed Study Program identified a regional flood

management project to address the issue. The problem:

its implementation cost was more than $8 million.

With an annual capital improvement budget of $5 million,

the city’s stormwater utility lacked the funds to move

forward. Madison applied for a FEMA Building Resilience

Infrastructure and Communities (BRIC) grant in 2020.

Unfortunately, the grant was denied.

The city reapplied in 2021, this time making the

application more competitive by detailing nature-based

solutions, highlighting additional resilience for the

infrastructure serving the clinics and daycares, and

renaming the project to reflect its nature-based and

resiliency features. The second funding application was

a success, providing Madison with $6 million in FEMA

BRIC grant funding.

Historically, Los Angeles has imported the majority of its

water. Its current infrastructure is unable to fully utilize

the city’s occasional storm events for beneficial use or for

much-needed groundwater replenishment. Recently, LA

passed the Green New Deal, which aims to locally source

70 percent of its water supply by 2035.

The infrastructure investment required to meet this

goal is immense. As such, Los Angeles Sanitation and

Environment (LASAN) is utilizing the LA’s Regional Safe

Clean Water (SCW) Program’s Regional Infrastructure

Program, which requires that all proposed efforts

describe how they will plan, build, and maintain multi-

benefit, watershed-based projects to improve water

quality, increase water supply, and enhance impacted

communities. One such effort is the MacArthur Lake

Stormwater Capture Project, which allows beneficial use.

To date, LASAN has secured $186.9 million for scientific

studies, infrastructure projects, and their operation and

maintenance from the SCW program.

Carollo’s stormwater infrastructure and funding experts

can help you determine if your project is eligible for federal

or local funding programs. We can also provide guidance

on the best ways to structure your application or project to

align with program goals and optimize competitiveness.

IS YOUR PROJECT

GRANT OR

LOAN READY?

CURRENTS / FEATURE STORY

As water utilities across the country grapple

with aging infrastructure, population growth,

and increasing climate uncertainties, a major

infrastructure initiative in the Pacific Northwest

demonstrates effective approaches to meet these

challenges. The Willamette Water Supply System

(WWSS)—spearheaded by the WWSS Commission,

a partnership of the Tualatin Valley Water District

and the cities of Hillsboro and Beaverton,

Oregon—is a $1.6 billion investment in resilient

water infrastructure.

The Willamette Water Supply Program (WWSP)

addresses multiple water system challenges

through integrated planning and design. The

system will deliver water from the Willamette River

to the rapidly growing Tualatin Valley through a

network of seismically resilient infrastructure. The

system’s cornerstone is a state-of-the-art, 60-mgd

water treatment facility, designed with expansion

capabilities to 120 mgd. This scalability enables the

facility to meet both current demands and future

growth without significant retrofits.

In addition to the water treatment facility, the

program encompasses 13 major projects, including:

� More than 30 miles of large-diameter

pipelines (66-inch and 48-inch) built to

modern seismic standards.

� A modified intake on the Willamette River.

� A 15-million-gallon terminal storage reservoir

on Cooper Mountain.

� Ancillary facilities designed to enhance

system reliability.

When complete, the WWSS will be one of the most

seismically resilient water systems in Oregon,

engineered to withstand natural disasters, protect

public health, and speed regional economic

recovery by restoring critical services following

natural disasters faster than ever before.

INSIGHTS FROM THE

PACIFIC NORTHWEST’S

LARGEST WATER

CONVEYANCE PROGRAM

ERIK PETERS (ecpeters@carollo.com)

MIKE WARRINER, PE

SCOTT GIBSON, PE

BUILDING

Tomorrow’s Water

Infrastructure

This joint effort between

contractors, program staff, and

operators from three different

owners is all coming together just

as planned, with the first water

deliveries to customers scheduled

for early 2026.”

—Tim Tekippe, Carollo Program

Commissioning and

Startup Manager

MANAGING CONSTRUCTION CHALLENGES

The project’s scale and complexity required

sophisticated construction management approaches.

Carollo, in partnership with Stantec, provides both

program management and construction management

services, having secured the construction management

contract in 2017.

The construction management scope includes oversight

of the intake, treatment facilities, reservoirs, and large-

diameter pipelines through a variety of jurisdictions. Some

system components, including the reservoir and major

pipeline segments, were constructed and tested up to

three years before final system integration. Others, such

as segments of pipe built to correspond with planned

roadway construction—known as “opportunity projects”

—were completed as much as eight years in advance.

This phased approach allows for thorough testing and

validation of each component while maintaining overall

program momentum and limiting public disruption.

Community Buy-In

To mitigate community concerns about construction

impacts such as traffic, noise, ground movement, and

site access both during and after construction, program

partners sponsored a coordinated public outreach

program. A significant portion of the pipelines were

originally routed through farmlands with no roadway

access. By partnering with local government agencies

such as Washington County, the Carollo/Stantec team

modified the routing of some pipe reaches to parallel

planned roadways to new developments. This significantly

improved buy-in from local growers by minimizing impacts

to their farms, while providing access during pipeline

construction and for future maintenance.

A Focus on Local Participation

To boost the local economy, WWSP offered opportunities

to as many local businesses as possible. Rather than hire a

team of consultants and builders from outside the region,

WWSP placed a high priority on giving those who live and

work in the community the opportunity to contribute to this

seminal project and share in its economic benefit. Efforts

have included significant outreach to recruit local trades,

contractors, and other businesses.

Bringing it All Together

Coordinating a major construction program so all

components come together smoothly takes planning

and skill. Key to success is implementing policies and

procedures to streamline the construction process.

For the WWSP, the strong emphasis on local business

involvement resulted in participation of a larger than

usual number of contractors. To keep costs in check,

maintain a rigorous schedule, and avoid potential rework,

the program employed specific contract language, and a

detailed construction

sequencing plan

aimed at seamlessly

transitioning the work

from one contractor

to another.

The commissioning

process presents

unique challenges,

including testing

a 15-million-gallon

reservoir for leaks,

connecting and

flushing more than

30 miles of large-

diameter pipe, and managing the associated water

disposal. With construction completion now in sight, a

comprehensive plan to address all interrelated program

elements is more critical than ever. The commissioning

team meets at least monthly to monitor construction and

refine the plan to adjust to evolving issues.

MEASURING SUCCESS

Despite the program’s complexity, it has evolved to

adapt to shifting technical, regulatory, and economic

issues over its 11-year duration, and work remains

on track to meet the original 2026 completion date

established in 2015. Plus, the overall program change

orders for the work currently stand at just one percent.

This achievement is a testament to the discipline and

technical acumen of the program participants. It reflects

the soundness of the program objectives and the

leadership of those dedicated to achieving them.

When complete, the system will provide exceptional

finished water quality, improved water conservation

measures, enhanced system safety, and greater

source reliability and redundancy for the region’s

growing population.

A SUSTAINABLE

WATER SUPPLY

for LOS ANGELES

Los Angeles has historically depended

on imported water from the State

Water Project, Colorado River, and

Los Angeles Aqueduct for the majority

of its drinking water needs. Prolonged

drought conditions affecting these

imported water sources, coupled with

seismic risks to conveyance infrastructure

crossing the San Andreas Fault, have

underscored the need for reliable and

sustainable local water supplies. In

response to these challenges, the city

has prioritized water recycling as a key

strategy for enhancing water security

and resilience.

Working Together

to Secure LA’s Water Future

In 2019, Los Angeles launched

an ambitious initiative targeting

100 percent water recycling at its four

water reclamation plants to source

up to 70 percent of the city’s drinking

water locally. This visionary program

marks a significant shift in water

management, focusing on replenishing

groundwater tables, diversifying

water supplies, and implementing

drought-resistant strategies for

Angelenos across the city, with equity

in distribution being a core principle.

Through a partnership between

Los Angeles Sanitation and

Environment (LASAN) and the

Los Angeles Department of Water

and Power (LADWP), the city

is implementing multiple water

recycling projects. A key component

of this effort is the advanced water

purification facility (AWPF) at the

Donald C. Tillman Water Reclamation

Plant (DCTWRP), which will produce

approximately 20 mgd of purified

water upon completion.

The existing DCTWRP plant site

encompasses approximately 90 acres,

with 6.5 acres dedicated to a Japanese

garden. The existing DCTWRP, with

a current flow of 55 mgd, provides

primary treatment, biological nutrient

removal, filtration, and disinfection.

When complete, the

state-of-the art advanced

water purification facility

at the DCTWRP will be

one of the largest IPR

facilities in the nation.

State-of-the-Art

Treatment Processes

The new AWPF will apply state-

of-the-art treatment processes

to supply 21,000 acre-ft/year of

purified water to replenish the

San Fernando Groundwater Basin.

The advanced purification process

employs several treatment and

disinfection steps before the water

can be recharged into the aquifer.

These involve clearing multiple

treatment barriers and providing

regular water quality monitoring

to optimize safety and protect

public health. The AWPF’s

processes include microfiltration,

reverse osmosis, and ultraviolet

advanced oxidation.

The facility’s advanced treatment

train is designed to process stable

tertiary effluent while consistently

meeting or exceeding California’s

stringent water quality standards

for groundwater replenishment.

Real-time monitoring systems

and automated controls facilitate

optimal performance across all

treatment processes.

The DC Tillman Water Reclamation Plant

is Helping Pave the Way for

100 Percent Wastewater Recycling

CURRENTS / PROJECT UPDATE

Kawana, the Japanese

Garden at the DCTWRP

is open year-round

and beautifully

demonstrates one of the

many positive uses of

reclaimed water.

LENEYDE CHAVEZ, MUP (lchavez@carollo.com)

ALI AHMADI, PhD, PE, PMP

GIL CROZES, PhD

Groundwater Replenishment

Following treatment, the purified water will be conveyed

to the Hansen Spreading Grounds through an existing

pipeline. The Hansen Spreading Grounds’ 117 acres of

engineered basins are designed to optimize infiltration

rates while maintaining stable groundwater levels. Regular

hydrogeological monitoring provides effective aquifer

management and tracks water movement through

the subsurface.

The groundwater replenishment process allows the water

to naturally filter through soil and percolate into the aquifer,

where it will remain for several years before extraction via

existing groundwater wells. The water will undergo further

processing at a drinking water treatment facility before

becoming part of LA’s drinking water supply.

LA’s Water Recycling Vision

The AWPF project is an essential

component of the Los Angeles

Groundwater Replenishment

Project, a large program

that aligns with LA’s water

management strategy, and accounts for approximately

15 percent of the Pure Water Los Angeles program

at buildout. LASAN and LADWP spent several years

researching advanced treatment options and working

with stakeholders before finalizing the facility’s design.

The project team, including Carollo as owner’s advisor,

has completed the AWPF design, and construction began

in December 2024. The facility is expected to be

operational in 2027.

This initiative complements LA’s broader water recycling

portfolio, which includes three additional facilities.

■ The AWPF at Hyperion Water Reclamation Plant is proof

of concept for full transformation to 100 percent recycling.

■ The Los Angeles-Glendale Water Reclamation Plant

processes and conserves more than one billion gallons

of potable water annually.

■ The Terminal Island Water Reclamation Plant can

produce up to 12 mgd of purified water for seawater

intrusion prevention, saving millions of gallons of potable

water each day.

To enhance public understanding and acceptance of water

recycling, Carollo developed a fun and informative educational

resource: The ABCs of Water Reuse. This colorful resource

uses the alphabet to explain key concepts, benefits, and the

science behind water reuse in simple terms. It’s suitable for

readers of all ages and is an essential tool for all those wanting

to learn more about recycled water!

Building Public Trust

Successful water recycling programs require careful

planning, stakeholder engagement, and community

outreach and education. Despite the proven benefits of

sustainable water management, utilities often face public

misperceptions about recycled water.

The LASAN, LADWP, and Carollo team has developed

stakeholder engagement and community education

initiatives focused on communicating the benefits of

wastewater reuse—including enhanced water security,

environmental protection, and consistent water quality.

Through transparent information sharing and community

outreach, the team is addressing public concerns while

maintaining confidence in water safety.

This project represents a significant advancement in

sustainable water management for urban areas. Its

success could serve as a model for other cities facing

similar water security challenges, demonstrating how

innovative treatment technologies and thoughtful

implementation can transform reclaimed water into a

valuable resource.

Making Water Reuse

Easy to Understand

LASAN and LADWP

experts speak

about the future

of wastewater

recycling in LA.

This project brings together the

community with a passionate team of

dedicated professionals, including two

of LA’s leading utilities.

Scan to download

The ABCs of

Water Reuse.

Water challenges across communities are driving the need for forward-

thinking solutions. Behind many of the innovative approaches addressing

today’s water issues stands Carollo’s Water Applied Research Center

(Water ARC®)—a comprehensive research hub where theory meets

application, and the future of water solutions takes shape.

DIVING

DEEP

Inside Carollo’s Water

Applied Research Center

Laboratory Testing Services:

Where Precision Meets Possibility

Under the direction of Katie Davis, our state-

of-the-art laboratory serves as the analytical

backbone of Water ARC®. Here, water

samples undergo rigorous examination—from

emergency and rapid-response diagnostics

and short-term testing to extended studies,

complex investigations, and custom or

condition-specific studies.

The lab’s capabilities extend to specialized

areas, including suspended ion exchange

(SIX®), ion exchange-based advanced

treatment (XBAT), ozone and UV disinfection,

wastewater inhibition, per- and polyfluoroalkyl

substance (PFAS) treatment, rapid small-scale

column tests (RSSCTs), and much more. If you

have unique testing requirements, we will

work with you to develop creative solutions to

deliver the data you need for your project.

JESS BROWN, PhD, PE (jbrown@carollo.com)

The Evolution

of Water ARC

The Carollo Research Group’s Water

ARC® has grown from a specialized

laboratory to a full-service partner

for Carollo’s projects, capable of

adapting to specific demands and

providing reliable expertise to handle

a wide array of water challenges. To

date, Carollo’s Water ARC® staff have

contributed to more than 400 applied

research projects impacting more than

5 billion gallons per day of water from

water and wastewater facilities.

But what truly sets our Boise-based

facility apart isn’t just its impressive

statistics—it’s the integrated approach

that brings together three specialized

programs to address the specific

needs of our municipal and private

sector clients.

“Our laboratory isn’t just

about running standard tests.

We specialize in creating

testing protocols for emerging

challenges that don’t yet have

established methods.”

— Katie Davis

Water ARC® Laboratory Manager

Three Pillars of Innovation

CURRENTS / WATER ARC® NEWS

Watch the Water ARC®

video to learn more.

Equipment Construction

Services: Building

Tomorrow’s Solutions Today

When off-the-shelf equipment

can’t address unique challenges,

Water ARC®’s equipment

construction services team steps

in. Led by Greg Stanczak, this team

designs and fabricates custom

equipment tailored to specific

project requirements.

Recent innovations include custom

bioreactors for specialized treatment

processes, Carollo’s inflatable fast

and lightweight off-gas analysis

technology (I-FLOAT) for wastewater

off-gas testing, and a bicarbonator

skid for sodium bicarbonate

SIX® regeneration.

“Every water challenge

has its own fingerprint. Our

ability to create purpose-

built equipment means

we can tackle problems

that standard tools simply

weren’t designed to solve.”

— Greg Stanczak

Water ARC® Equipment

Construction Services

Manager

Pilot and Field-Testing

Services: Proving Concepts

in Real Conditions

The journey from laboratory to full

implementation requires rigorous

field validation. With a fleet of

over 20 pilot skids and a wide array

of field equipment, Carollo’s pilot-

and field-testing services team, led

by Luke Snell, helps clients explore

viable solutions, confirm efficacy,

and make informed decisions to

deliver successful projects.

Our services span the entire pilot

testing lifecycle—from initial facility

design through construction,

commissioning, operation,

troubleshooting, and modification.

The team regularly provides pilot

support for testing microfiltration/

ultrafiltration membranes, reverse

osmosis processes, ozone treatment,

flocculation/sedimentation

configurations, filtration technologies,

pipe loop skids, and more. In addition,

handheld meters, probes, and other

field equipment aid in data collection

and analysis.

“Pilot and field testing

eliminates surprises and

provides the confidence

our clients need before

committing to full-scale

implementation.”

— Luke Snell

Water ARC® Pilot-and Field-

Testing Services Manager

Water ARC

Testing Saves Millions

for New Smyrna Beach Utilities

Carollo is participating in a pellet softening project for

Florida’s New Smyrna Beach Utilities (NSBU) that includes

total trihalomethane (TTHM) mitigation. NSBU’s water

treatment plant had never exceeded TTHM or haloacetic

acid (HAA5) maximum contaminant levels, but levels were

high enough that the utility wanted to examine them.

In response to organics levels, warm water temperatures,

and the short free chlorine contact time (CT)—enough to

get 4-log virus inactivation—many Florida utilities have

turned to air stripping technologies. But this approach only

focuses on removal of chloroform.

Carollo proposed to do limited testing to quantify air

stripping’s effectiveness at NSBU by answering the

following questions:

■ How quickly do TTHMs and HAA5 form?

■ What percentage of TTHMs is chloroform?

Carollo’s Water ARC® tested plant samples to measure

disinfection byproduct (DBP) formation over time and the

results were surprising.

■ DBP formation was not as fast as anticipated. TTHM

formation was 23 μg/L with 7 minutes of CT, and 45 μg/L

with 28 minutes of CT. Theoretically, the CT needed for

4-log reduction with typical settled water quality is

3 to 4 minutes.

■ Chloroform formation was initially 83 percent of the

TTHM but dropped to 67 percent at 28 minutes of CT.

During testing, Carollo also reviewed the existing plant

configuration and found the following:

■ The chlorine contact basin was poorly baffled (later

revealed to have a t

/T of 0.38).

■ Volatilization of chloroform would be more expensive due

to multiple distribution system storage tanks. A revised

approach to pull water from the clearwell beneath the

filters and process it through a packed tower had an

anticipated cost of $1 to $2 million.

Water ARC®’s data revealed a better solution: Improve the

baffling factor and reduce CT with free chlorine—all while

continuing to maintain 4-log virus inactivation with

a conservative safety factor.

The selected alternative was to upsize the piping from the

pellet softening process and allow all the CT in the pipeline,

which is a perfect contactor (t

/T of 1.0). This option can save

millions, is simple to operate, and can reduce the TTHM by

50 percent and the HAA5 by 33 percent.

In our culture

In our solutions

In our communities

800.523.5826 / carollo.com

Like water itself, innovation ﬂows through every challenge and shapes new possibilities. For over 90 years,

Carollo has pioneered breakthroughs in water technology—from resilient infrastructure protecting growing

communities to groundbreaking solutions safeguarding public health and ecosystems. At Carollo, innovation

isn’t just about what’s new—it’s about what’s necessary. Every advancement, every improvement, and every

solution ﬂows from a single purpose: shaping a future where water enriches every community it touches.

Where do you ﬁnd Carollo

Innovation?