Carollo Engineers, Inc.

Carollo Engineers, Inc. Carollo Engineers is an environmental engineering firm specializing in the planning, design, and con

Carollo Engineers is an environmental engineering firm that specializes in the planning, design, and construction of water and wastewater facilities. The firm was founded in Phoenix, AZ in 1933, and counts the City of Phoenix among one of our original clients—a working relationship more than 80 years old! From that single office with three engineers, Carollo has grown to nearly 1000 people in 42 o

ffices throughout the United States. Our staff includes civil, structural, electrical, mechanical, environmental, and instrumentation and control engineers as well as scientists, planners, architects and CAD designers. Cities, utilities and special districts of all sizes count on Carollo to help them navigate through the increasingly complex challenges of cost-effectively and sustainably protecting public health, meeting local, state and federal regulatory requirements, protecting the water environment, and addressing public expectations. Our core philosophy for success is to work collaboratively with our clients to find the best ways to protect and enhance our public water supplies and our lakes, streams, rivers and oceans. We recognize that water sustains life on this planet and clean, safe water sustains healthy ecosystems and healthy communities. Our employees are proud of our role in making the communities that we live in, work in, and serve, better places to live. We continually strive to emulate our mission statement: "Dedicated to creative, responsive, quality solutions to those we serve."

"What if something goes wrong?" That's the question at the heart of Hazard and Operability (HAZOP) reviews.A recent Jour...
09/03/2026

"What if something goes wrong?" That's the question at the heart of Hazard and Operability (HAZOP) reviews.

A recent Journal American Water Works Association article by Carollo's SJ Hall, Milissa Hirst, Gregory Parana, and Shawn Corrigan highlights how this structured process helps utilities identify potential hazards, improve operability, and strengthen facility resilience before construction is complete.

Learn why HAZOP is becoming an increasingly valuable tool for water and wastewater utilities looking to reduce risk and improve long-term reliability:
https://carollo.com/publications/hazop-reviews/

09/02/2026

A major milestone for Highlands Ranch Water: Phase 1B improvements at the Joseph B. Blake Water Treatment Plant are now complete.

The upgrades strengthen reliability, redundancy, and safety at the 40 MGD facility, which provides drinking water to more than 100,000 people. Delivered through a collaborative CMAR approach with Carollo Engineers providing design and construction management services and Garney serving as general contractor, the project was completed more than $1 million below the guaranteed maximum price.

With Phase 1B complete and design of Phase 2 underway, Highlands Ranch Water continues its long-term investment in modernizing this critical facility.

Learn more about the project:
https://carollo.com/press-releases/joseph-blake-wtp/

Water reuse is no longer just a drought response; it's becoming a core strategy for building resilient, long-term water ...
08/31/2026

Water reuse is no longer just a drought response; it's becoming a core strategy for building resilient, long-term water supplies. But what separates the potable reuse projects that move from concept to reality from those that never get off the ground?

In a recent episode of the Talking Under Water podcast, Carollo's Pranjali Kumar shares why successful reuse projects require far more than advanced treatment technologies. From engaging regulators early and building organizational alignment to investing in strong project leadership and public trust, she explains what it takes to turn ambitious water reuse programs into lasting community assets.

Learn more: https://carollo.com/news/pranjali-jumar-on-water-reuse/

Next week, we’re headed to Indiana for the American Water Works Association Water Infrastructure Conference!Carollo team...
08/27/2026

Next week, we’re headed to Indiana for the American Water Works Association Water Infrastructure Conference!

Carollo team members will be contributing to conversations across the conference, with presentations, panels, and workshops exploring utility resilience, asset management, natural hazard risk, project delivery, and planning for major infrastructure investments.

If you’re attending, be sure to add our sessions to your schedule. We look forward to connecting with the water infrastructure community in Indianapolis!

08/26/2026

Congratulations to Mojave Water Agency on the ribbon cutting for the Mojave River Pipeline Traveling Screen Project!

This important investment strengthens regional water reliability by restoring the Mojave River Pipeline, reducing moss and debris entering the system, and expanding the Agency’s ability to capture and recharge water during wet years. The improvements will support a more resilient water supply for communities throughout the region, including West Victorville and Phelan.

Carollo is proud to have served as the project designer, working alongside Nicholas Construction and Kennedy Jenks to help bring Mojave Water Agency’s vision to life.

We’re excited to celebrate this milestone with MWA and the entire project team!

08/25/2026

How do you plan for water challenges 50 years into the future?

In a recent interview with Water Online, Carollo's Amber Wooten discusses the development of the 2025 Oklahoma Comprehensive Water Plan, including how technical analysis, stakeholder collaboration, and long-term scenario planning can help utilities prepare for an uncertain future.

Learn more about the planning process and watch the full interview:
https://carollo.com/news/long-term-water-planning/

Please join us in welcoming Ella to our Washington D.C. office! Ella brings over 20 years of proven infrastructure exper...
08/21/2026

Please join us in welcoming Ella to our Washington D.C. office!

Ella brings over 20 years of proven infrastructure experience spanning planning, contract management, and delivery for large capital programs.

In prior roles as an Owner and Consultant, she has managed multibillion-dollar capital improvement programs, including leading planning, prioritization, and delivery of DC Water’s $2 billion CIP spanning water and sewer systems, and delivering $3.5 million in cost savings across consecutive fiscal years.

Ella excels at establishing performance metrics, strengthening accountability, and aligning complex portfolios with long-term investment goals to help utilities plan, prioritize, and deliver critical infrastructure investments efficiently.

Extreme weather, cyber threats, supply chain disruptions, and workforce challenges are changing how water utilities thin...
08/18/2026

Extreme weather, cyber threats, supply chain disruptions, and workforce challenges are changing how water utilities think about resilience.

In his recent Water Environment Association of Ontario (WEAO) Influents magazine article, Shawn Corrigan explores how utilities can move beyond traditional emergency planning by integrating risk assessment, continuity planning, and emergency management into a more resilient operating model.

Learn how an integrated approach can help utilities better prepare for today's evolving risks:
https://carollo.com/publications/operational-resilience-in-canada/

08/17/2026

"The worst thing you can do now on PFAS is take your foot off the gas."

In a recent Water Online interview, Carollo's Alan Roberson discusses how utilities can prepare for evolving drinking water regulations, prioritize investments, and develop long-term compliance strategies despite regulatory uncertainty.

Learn more about his insights and watch the full interview:
https://carollo.com/news/evolving-drinking-water-regulations

The City of Odessa, Texas is investing in the future of its water infrastructure with a new Bob Derrington Water Reclama...
08/12/2026

The City of Odessa, Texas is investing in the future of its water infrastructure with a new Bob Derrington Water Reclamation Plant. The new facility will replace aging infrastructure while strengthening reliability, improving treatment performance, and supporting continued water reuse for the community and local industries.

Carollo Engineers has been selected to lead the design and provide engineering services from early planning through construction, helping deliver a modern, operator-friendly facility that will serve Odessa well into the future.

Learn more about the project:
https://carollo.com/press-releases/bob-derrington-wrp/

Address

2795 Mitchell Drive
Walnut Creek, CA
94598

Opening Hours

Monday 8am - 5pm
Tuesday 8am - 5pm
Wednesday 8am - 5pm
Thursday 8am - 5pm
Friday 8am - 5pm

Telephone

(800) 523-5826

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