Coordination, Innovation, and Respect for the Environment

At the heart of Duluth, Minnesota—near Lake Superior—Brennan led a large-scale environmental remediation project at Munger Landing, removing historical contamination from over 34 acres of the St. Louis River. This multi-year effort addressed legacy pollutants including PCBs, mercury, dioxins, and furans through precision hydraulic dredging, sediment dewatering, water treatment, and the strategic placement of clean sand and habitat materials.

"The scale and scope of this project demanded constant coordination, innovation, and respect for the environment," says Project Manager Casey Evenson

Refinery Wastewater Pond Cleanup with Remote Dredging

We recently completed the cleanup of two wastewater ponds for a large producer of transportation fuels. Using a remotely controlled dredge, Brennan removed wastewater sludge from impoundments on the refinery site and dewatered the material with six 2-meter belt filter presses. The remotely controlled dredge added a layer of safety to the project, preventing any health risks that a Leverman might face if exposed to hydrogen sulfide gas released during the dredging process.

The Third Ward Milwaukee River remediation project is a pivotal step in cleaning up the Milwaukee River. It targets the site of a decommissioned manufactured gas plant that once operated in the area. 

A Collaborative Effort to Clean Milwaukee's River

Brennan was selected as the prime contractor for this ambitious project, tasked with dredging contaminated sediments and treating water to restore the river's health. Working closely with GEI Consultants, Inc. (GEI), the project’s design engineers, Brennan is delivering comprehensive solutions that combine environmental restoration, water treatment, and marine construction expertise.

Treatability testing uses bench-scale demonstrations and analysis to determine if a material can be effectively treated with a specific chemical or process. At Brennan, we use treatability testing to develop sound technical approaches for dredged material dewatering, in situ or dewatered dredged material stabilization, and water treatment. 

Treatability data can be used to price a job more accurately and find cost savings for our clients. Treatability testing allows us to select chemical and mechanical processes for treatment and evaluate less costly alternatives. Here's how we do it.

Our equipment safely navigates where barges can’t float and where ground equipment can’t trek. Brennan’s specialty amphibious trucks can float fully loaded with a 20-cubic yard payload or be configured to support geotechnical drilling equipment. See our equipment in action with this video! 

The US Environmental Protection Agency (EPA) and Minnesota Pollution Control Agency (MPCA) signed a project agreement to remediate contaminated sediment in the “ponds behind Erie Pier,” two ponds surrounded by shallow marsh wetlands in the St. Louis River Area of Concern (AOC).

The sediment was primarily contaminated with PCBs, PAHs, mercury, and chromium. Here's how we worked with stakeholders to clean up the sediment and the resulting impact of our work.

The Cuyahoga Improvement Project in Kent, OH, aims to improve future recreation experiences while protecting existing natural resources. The purpose of our work is to remove areas of petroleum-impacted soft sediments that were deposited decades ago from discontinued industrial practices upstream. 

Background on a Burning River

The Cuyahoga River has quite a history: a transportation route; a boundary; an origin for oil, rubber, and steel industries; a power source; and a dumping ground. The river was once 1 of the most polluted in the country. The Cuyahoga has caught fire at least 13 times since the 1860s.

February 6, 2023 — Specialty marine contractor J.F. Brennan Company, Inc. (Brennan) recently finalized the asset acquisition of the dredging and dewatering division of Infrastructure Alternatives, Inc. (IAI). The purchase brings dewatering, water treatment, and treatability testing services into the organization for the first time.

Last fall, J.F. Brennan Company, Inc. (Brennan) crews successfully concluded environmental remediation efforts after 3.5 years on the Grasse River in Massena, NY. This project had a challenging scope involving dredging, material processing, water treatment, mussel relocation, capping, and habitat restoration. Through a combination of strong teamwork and outstanding production efficiencies, our team completed every phase of work and executed a safe demobilization. Here’s how we did it.

Our experience in wetland habitat restoration began decades ago with the Upper Mississippi River Restoration Program (UMRR), the largest restoration program ever undertaken on a major waterway worldwide.  Since then, restoring marshes, wetlands, and highly sensitive ecosystems along inland and coastal waters nationwide has been a main initiative.