U.S. Army Corps of Engineers, Pittsburgh District - Mahoning River, Ohio Environmental Dredging

The purpose of this study is to investigate the feasibility and the extent of federal interest in remediation of the Mahoning River in Trumbull and Mahoning Counties, Ohio. The ecosystem has been adversely affected by contaminated river sediments, which are a legacy of the heavy industrial development in the Mahoning Valley throughout most of the 20^th century. This project will restore the aquatic ecosystem in the Mahoning River over a distance of approximately 34 stream miles, from the Pennsylvania – Ohio state line at river mile 11.8 to Leavittsburg Lovers Lane Dam at river mile 45.3.

The 1^st phase of the project, a reconnaissance study, was completed in May 1999. The reconnaissance study identified a federal interest (benefits outweigh the cost) to remove and remediate approximately 750,000 cubic yards of contaminated in-river and riverbank materials at an estimated cost of $100 million¹. Annual benefits, measured in recreational user days, are estimated at $29 million annually¹.

The project is currently in the 2^nd phase, the feasibility study, which was initiated in March 2002. Eastgate Regional Council of Governments is our 50%-50% cost sharing partner for the $3 million Mahoning River, Ohio, Environmental Dredging feasibility study.

The scope of the feasibility phase includes more detailed studies and investigations than were accomplished during preparation of the reconnaissance study. Based on the recommendations in the 1999 Reconnaissance Report, the feasibility study will evaluate the following major construction activities:

dredging (mechanical, hydraulic, etc.) of the contaminated sediments,
dewatering,
water treatment,
excavation of contaminated bank material,
stabilization of contaminated bank material, and
placement options, including bioremediation and beneficial reuse.

There will also be additional chemical sampling of strategic sections of both the river channel and near-shore areas to confirm that no hazardous or toxic material lies within the project area. Other general areas of study include estimation of utility relocation requirements due to the proposed dredging, mitigation of bank impacts and restoration of Mahoning River substrate in the area to be dredged. The feasibility study will culminate with the identification of a recommended plan for implementation. In the process of arriving at a recommended plan, the environmental, socioeconomic and engineering impacts of the remediation project will be analyzed.