Marine construction & environmental services

Brennan designs and executes innovative solutions to the world’s most complex maritime, environmental, and infrastructure challenges.

We’ve Been Building For Over 100 Years

— EST 1919 —

Brennan is a fourth-generation, family-owned marine construction firm specializing in environmental remediation, dam construction, commercial diving, harbor management, and submarine cable services. Since 1919, Brennan has worked with public and private owners of water-based infrastructure and operates throughout coastal and inland waterways nationwide.

About & History

Contact Our Main Office

(608) 784-7173

What We Do

Brennan’s Areas of Focus

  • Energy Services

    At Brennan, we provide quality above- and below-water marine construction, barge transportation, and environmental remediation services to the energy industry.

  • Environmental Services

    Whether you need dive services to repair underwater concrete or help restore wetlands following a project, J.F. Brennan Company offers a wide variety of services to fulfill your project needs.

  • Marine Construction

    Brennan offers flexible approaches and innovative solutions to successfully restore contaminated waterways and wetlands through innovative tools and research.

  • Dam Construction

    We work on every part of the dam, both above and below the waterline, and our crews have the experience and equipment necessary to work in a variety of conditions, including underwater.

  • Harbor Services

    Our harbor management services provide inland harbor services for utility companies, dry bulk terminals, and specialty large bulk shippers along the Mississippi River.

  • Dive Services

    We have more than 100 ADCI-certified commercial divers on staff throughout the US that specialize in underwater construction.

No Job Too Big or Small

Dive Services

Our teams are trained to the highest standard, utilizing the newest technologies in underwater services to accomplish difficult tasks in near zero-visibility. We specialize in inland waterway and wastewater diving services.

100+

ADCI Certified Commercial Divers

Learn From Our Experts

We share insights on our specialized projects, and feature highlights from our dedicated team members.

DISCOVER WHAT’S POSSIBLE!

We tackle complex projects, work hard, provide solutions and celebrate. We’re risk-takers, fast learners, and experts in our fields. Together, we’re redefining our industry.

Safety First, Quality Always.

The J.F. Brennan Company’s Commitment to Marine Safety

We combine environmental stewardship with rigorous safety measures. Our innovative methods ensure the well-being of both ecosystems and our workforce.