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who we are< quality / history >


We are dedicated to delivering maximum value to clients and their local communities.

MWH is a leading water and wastewater treatment-focused general contractor with experience in both municipal and industrial applications. Whether it’s building new facilities, improving infrastructure, or expanding existing systems, MWH has the expertise to successfully fulfill a wide range of client needs. Our experience with a full range of project delivery methods ensures that we can tailor our approach to meet the unique needs of each project.


Founded by some of the world’s leading innovators…

in water and wastewater technology with roots going back to 1820, we continue to be at the forefront of advancements in treatment processes and project delivery.
MWH has an expansive nationwide presence, including Slayden Constructors in the Pacific Northwest and Methuen Construction on the East Coast.


We are rooted in our history.

In the 19th century, we revolutionized clean water at the turn of a tap, saving countless lives during a deadly cholera outbreak. In the 20th century, we introduced some of the first sewage processing machinery of its kind. In the 21st century, we are among the first to bring Thermal Hydrolysis technology to U.S. soil. For two centuries we have established ourselves as trailblazers in water and wastewater technology and we will continue that legacy. Read about more about our fascinating, 200 year old history below.

The MWH Way

We act with integrity.

There is no substitute for honesty and transparency. In all our operations, accountability and follow-through is essential. Our action is our word. We do the right thing even when it’s hard.

We prioritize safety.

On every project, at every moment, without compromise, safety is our foremost concern. If we see something, we say something.

We are committed to quality.

A reputation for excellence is forged over time. It’s a mindset and a daily practice. We make sure we build projects right the first time, with a commitment to the highest standards of quality and value.

We are innovative.

Our daily commitment to the development and implementation of novel ideas and pioneering solutions delivers results.

We value growth.

Business and personal growth are inextricably linked, driving our evolution as a company. At MWH, we take lessons learned to heart and never cease aspiring to better ourselves.

We are leaders.

For over 200 years, we have forged new paths and led our industry into the future. Today, we’re continuing that tradition by instilling authentic leadership skills within our teams.

We are team players.

We build customer relationships characterized by mutual trust, cooperation, and responsibility designed to fulfill the needs and realize the goals of our clients. As an organization, we teach and learn from each other, treating each other with confidence and respect.

We are experts.

Our value resides in our people. We seek out rising stars and the brightest experts in the field, supporting their growth through mentorship and individualized training experiences.

Recent News

MWH’s Community-Centered Approach at San Francisco’s Biosolids Digester Facilities Plant

The Biosolids Digester Facilities Project (BDFP) project is transcending the conventional boundaries…

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Tres Ríos Water Reclamation Facility Ten-Year Anniversary

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Hydrolager – Crafting Sustainability in Every Sip

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