Carollo Engineers

What Carollo Engineers does

Carollo Engineers is a U.S.-based, privately held (ESOP-owned) environmental engineering consulting firm founded in 1933 and headquartered in Walnut Creek, California. It is the largest water-only consulting firm in the U.S., ranked No. 1 by Engineering News-Record (2024) among firms specializing in water, with 513+ dedicated professionals and 15,000+ projects delivered nationwide. The firm plans, designs, and manages construction of municipal drinking water, wastewater, water reuse, and stormwater infrastructure for public-sector clients, with a growing industrial/private-sector practice.

The firm's core offerings combine full-lifecycle engineering services with proprietary technology products. Engineering services span planning, design, construction management, program/owner advisory, asset management, and operations support. Proprietary technology includes the Blue Plan-it® decision-support platform (Monte Carlo simulation, multi-objective optimization, genetic algorithms), the Water ARC® applied research center in Boise (8,900 sq ft of bench/pilot/demonstration facilities), patent-pending XBAT ion-exchange treatment technology, I-FLOAT off-gas testing, EPIC® electrical/instrumentation/SCADA services, and the CarolloDIGITAL digital-water suite. R&D output includes 6 process patents (3 pending), 170+ applied research projects over 5 years, and $25M of funded R&D over 7 years.

Carollo generates revenue primarily through professional-services fees under project-based contracts with municipal and government water utilities, procured via qualifications-based selection and competitive bidding. Contract values range from planning studies to multi-year, multi-hundred-million-dollar construction management and program management engagements (e.g., $330M Medford, $210M Ophir, $200M OneWater Nevada). The firm also pursues non-dilutive public funding (EPA WIFIA, DOE) and engages in research partnerships with ASU, Colorado School of Mines, and technology licensors such as PWNT. Distribution is direct enterprise sales to public agencies, supplemented by industry thought leadership (Currents magazine, technical publications, conferences) and a national office footprint spanning California, the Pacific Northwest, the Mountain West, the Southwest, the Mid-Atlantic, and the Southeast.

Name

Carollo Engineers

Legal name

Carollo Engineers, Inc.

Website

https://carollo.com

Company type

Private

Founded year

1933

Operating status

Operating

Headcount range

1,001–5,000 employees

Short description

Carollo Engineers is a U.S.-based, employee-owned environmental engineering consulting firm (founded 1933, ENR No. 1 in water) that plans, designs, and manages construction of water, wastewater, reuse, and stormwater infrastructure for municipal utilities, government agencies, and select industrial clients.

Ownership category

akta.pro rank

Product category

Water and Wastewater Engineering Consulting

NAICS

Engineering Services (54133), Architectural, Engineering, and Related Services (5413), Environmental Consulting Services (541620), Water and Sewer Line and Related Structures Construction (23711)

SIC

Services-Engineering, Accounting, Research, Management (8700), Water, Sewer, Pipeline, Comm & Power Line Construction (1623)

akta.pro primary industry

Water, Wastewater & Hydraulics Engineering Consulting (BPAHAIAD)

akta.pro secondary industries

Construction Management & Delivery (EPCM/CMAR/Design-Build Oversight) (EUANALAE), Maintenance & Reliability (RCM, Work Management, Spares) (EUANALAH), Water & Wastewater Compliance (NPDES/Stormwater, Pretreatment, Drinking Water/SDWA) (EUAHABAB)

Keywords

• Water engineering consulting
• Wastewater treatment design
• Municipal water utilities
• Water reuse solutions
• Construction management services

Headquarters

HQ city

Walnut Creek

HQ country

United States

HQ region

North America

Offices6 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Technology or R&D, Operations, Marketing or Sales, Infrastructure

Revenue model

1. Engineering Consulting and Design Services: Professional engineering services for water and wastewater facilities including planning, design, permitting, and construction support. Revenue generated through fee-based consulting contracts with municipal and government clients.
2. Construction Management Services: Construction management contracts for water treatment plant and wastewater facility projects. Recent contracts include $210M Ophir Water Treatment Plant (Phase 1) and $200M Advanced Purified Water Facility in Nevada.
3. Program Management and Owner Advisory: Owner advisory and program management services for large multi-year water infrastructure programs. Includes project planning, prioritization, procurement, project controls, and engineering/construction oversight.
4. PFAS Assessment and Treatment Services: Specialized consulting for PFAS contamination including planning studies, pilot testing, RSSCTs, conceptual designs, and full-scale treatment facility design.

Pricing tiers

Go-to-market motion1 record

Distribution channels1 record

Marketing channels10 records

Core offering

Carollo Engineers is a full-service environmental engineering consulting firm that plans, designs, and supports construction of water and wastewater facilities for municipal utilities, sanitation districts, and public agencies. The firm provides drinking water treatment, wastewater treatment, water reuse, water infrastructure planning, PFAS treatment, asset management, and construction/program management services, supported by proprietary technologies such as Blue Plan-it®, Water ARC®, XBAT, EPIC®, and CarolloDIGITAL.

Product overview

Carollo Engineers operates as a water-focused engineering consulting firm offering a comprehensive portfolio of services and proprietary technologies for water and wastewater utilities. The core offerings include specialized engineering consulting services (drinking water, wastewater, water reuse, water resources, stormwater management, infrastructure planning, asset management, renewable energy) supported by proprietary technology products including Blue Plan-It® decision support platform, Water ARC® applied research center, EPIC® electrical and control systems, XBAT advanced treatment technology, I-FLOAT off-gas testing, and CarolloDIGITAL solutions. The firm has completed over 15,000 projects nationwide with $1.1B in new construction projects.

Differentiator

Problem solved

Functional benefit

Brands

• Blue Plan-it: A decision support platform developed by Carollo that combines data management, analytics, integration, and visualization to help utilities plan water and wastewater systems dynamically and transparently.
• Water ARC (Water Applied Research Center)
• CarolloDIGITAL
• EPIC (Electrical, Programming, Instrumentation and Control)
• Water ARC
• XBAT (Ion eXchange-Based Advanced Treatment)
• I-FLOAT (Inflatable Fast and Lightweight Off-Gas Analysis Technology)
• Carollo Cares
• CAMP (Collaborative Accelerated Meeting Process)
• Carollo Research Group (CRG)

Quantifiable outcome

• 40+ billion gallons of reclaimed water produced annually through water reuse projects
• +9 more outcomes

Named customers11 records

Segments6 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability5 records

Feature6 records

Partnerships

Nine partnerships are on record, tiered core, minor and flagship.

• CDM SmithcoreStrategic or Co-development Partner · 29 January 2026Carollo Engineers working in association with CDM Smith to design PFAS treatment upgrades for Broward County, Florida drinking water treatment and transmission infrastructure. Project includes nanofiltration at both water treatment plants and approximately 6 miles of transmission main. This represents one of the largest PFAS treatment efforts in Florida.
• Slayden ConstructorscoreStrategic or Co-development PartnerPart of consortium delivering $330M Medford, Oregon Regional Water Reclamation Facility overhaul. Slayden serves as constructor alongside engineering partners West Yost, Black & Veatch, and Carollo Engineers.
• West YostcoreStrategic or Co-development PartnerPart of consortium delivering $330M Medford, Oregon Regional Water Reclamation Facility overhaul. West Yost provides engineering services alongside Slayden Constructors, Black & Veatch, and Carollo Engineers.
• Black & VeatchcoreStrategic or Co-development PartnerPart of consortium delivering $330M Medford, Oregon Regional Water Reclamation Facility overhaul. Black & Veatch provides engineering expertise alongside Slayden Constructors, West Yost, and Carollo Engineers.
• Water For PeopleminorStrategic or Co-development PartnerInternational nonprofit bringing safe water and sanitation to global communities. Carollo has supported Water For People through workplace giving since 2006, with over $1 million donated by company and employees. Carollo sponsors annual Impact Tours for employees to observe Water For People's work in target countries including Guatemala, Honduras, Peru, Bolivia, Uganda, Rwanda, Malawi, Tanzania, and India.
• PWNT (Process Water Network Technology)coreTechnology or IntegrationLicensor of Suspended Ion Exchange (SIX®) technology used in Carollo's XBAT treatment system. PWNT developed the novel ion exchange process where resin flows through contactors and is separated by plate settlers.
• Arizona State University (ASU)coreStrategic or Co-development PartnerResearch partner for PFAS treatment studies. Carollo worked with ASU to conduct 40+ sets of RSSCTs evaluating PFAS removal through carbons and IX resins. ASU also collaborated on developing modified RSSCT methods for IX testing validated against pilot- and full-scale data.
• Colorado School of MinesminorStrategic or Co-development PartnerResearch partner working with Carollo to pilot-test innovative UV-bisulfite treatment process to degrade PFAS from nanofiltration concentrate for brine management.
• City of TampaflagshipStrategic or Co-development PartnerStrategic partner for world's largest Suspended Ion Exchange (SIX®) system at David L. Tippin Water Treatment Facility. Carollo's Water ARC provided full-time design and implementation support for dynamic pilot study. Project will process 140 MGD and serve as key demonstration site for SIX® technology in the U.S.

Scale indicators13 records

Recent moves6 records

Expansion highlights7 records

Direct peers

• Black & Veatch: Large engineering, construction, and consulting firm with a prominent water practice spanning treatment plant design, conveyance, and program management. Partnered with Carollo on the $330M Medford Regional Water Reclamation Facility consortium, indicating direct head-to-head bidding on the same marquee U.S. municipal programs.
• CDM Smith: Global engineering and construction firm with a strong water/wastewater practice serving municipal clients on planning, design, and construction management. Partnered with Carollo on Broward County PFAS upgrades, illustrating direct co-bidding on U.S. drinking water programs.
• Hazen and Sawyer: Privately held, pure-play water and wastewater engineering firm competing with Carollo for the same U.S. municipal utility clients across drinking water, wastewater, stormwater, and resource recovery projects.
• Brown and Caldwell: Employee-owned consulting firm focused exclusively on water and environmental infrastructure, directly competing with Carollo on planning, design, and construction management services for municipal utilities.

Broad incumbents

• Jacobs Solutions: Large diversified engineering professional services firm with a substantial Critical Mission Solutions and water practice competing for municipal and industrial water/wastewater work as part of a much broader portfolio.
• AECOM: Global infrastructure consulting giant with a dedicated water business pursuing many of the same municipal treatment, conveyance, and program management opportunities as Carollo at federal, state, and local levels.
• Stantec: Canadian-based engineering, architecture, and environmental services firm with a sizable water practice pursuing U.S. municipal and industrial water/wastewater consulting opportunities.
• Tetra Tech: Consulting and engineering firm with deep water, environment, and infrastructure practices serving U.S. utilities on water resource management, treatment, and wastewater projects alongside broader federal and international work.
• HDR Inc. Employee-owned engineering and consulting firm with a meaningful water resources, treatment, and wastewater practice pursuing the same municipal clients and federal water infrastructure programs as Carollo.
• Arcadis: Global design and consultancy with a sizable water and resilience practice, competing for U.S. municipal water and wastewater engineering and program management opportunities as part of a broader environmental portfolio.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks7 records

Key highlights7 records

Customer concentration

• Xx.com/carollotweets
• YouTubeyoutube.com/CarolloVideoNetwork
• Facebookfacebook.com/carolloengineers
• LinkedInlinkedin.com/company/carollo-engineers

Revenue estimate

Valuation estimate

Number of profiles

Profiles32 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Carollo Engineers