ANNOUNCEMENT

It was announced on Great Lakes Dredge and Dock Corporation’s earnings call, that Terra Contracting Services, LLC (Terra) has entered into a definitive agreement to sell the assets associated with its service lines of business (including underground infrastructure, abatement, emergency response, industrial services, oil & gas, and pipeline services). The sale excludes the personnel and assets associated with Terra’s remediation service line which will continue to operate under the Terra Contracting Services, LLC name as a division of Great Lakes Environmental and Infrastructure Solutions (GLEIS).

We see this as a very necessary and positive development for the Company that will further clarify and strengthen our position in the environmental construction market and gives us the opportunity to focus on our core competencies – remediation and geotechnical construction. It furthers Great Lakes Dredge and Dock’s strategic vision to be a leading provider of environmental restoration and remediation projects in-water and on land with emphasis on targeting large multi-million dollar contracts that best leverage the Company’s financial, operational, and brand strengths.

We expect the transaction to close by end of September.

GREAT LAKES ENVIRONMENTAL & INFRASTRUCTURE SOLUTIONS

Great Lakes Environmental & Infrastructure Solutions (GLEIS) is one of the largest environmental construction companies in the US offering geotechnical, remediation, and dredging services. The key members of our management team have more than 150 years of combined field experience performing a wide range of successful projects which allows GLEIS to deliver “Best in Class” technical solutions and implementation strategies at the best possible value.  GLEIS is a subsidiary of Great Lakes Dredge & Dock Corporation (NASDAQ: GLDD) with two operating segments, GLEI and Terra Contracting Services, LLC.