Conowingo Sediment Characterization and Innovative and Beneficial Reuse Pilot

​​Since Conowingo Dam’s construction in 1929, sediments flowing down the Susquehanna River have been building up in its reservoir. Recent studies by the U.S. Geological Survey indicate that the reservoir is effectively full of sediment which means that more of those sediments, and the nutrients associated with them, are washing downstream into Chesapeake Bay during storms. A follow up study led by the Department’s of Environment (MDE) and Natural Resources, the U.S. Army Corps of Engineers, Susquehanna River Basin Commission and EPA’s Chesapeake Bay Program (CBP) found that those sediments and nutrients are contributing to dissolved oxygen impairments in the Chesapeake Bay.  CBP has quantified the nutrient contribution from Conowingo infill as resulting in an additional 6-million pounds of total nitrogen and 260,000 pounds of total phosphorus load that is affecting dissolved oxygen levels in Chesapeake Bay.  Governor Hogan has made addressing Conowingo Dam’s impacts a top Chesapeake Bay restoration priority.

The Governor has made addressing Conowingo Dam’s pollution impacts a priority in Maryland’s Chesapeake Bay Restoration effort and the State must certify that water quality standards will continue to be met with Dam operation. The Conowingo Sediment Characterization and Innovative Reuse and Beneficial Use pilot project will provide Maryland with better information on the quality of sediments behind the dam, dredging costs, dredged material reuse options, scaling, and feasibility as a solution for addressing Conowingo’s impacts. A revised request for proposals for this project was issued on November 13th, 2018 and Northgate-Dutra (ND) was awarded the contract in February 2019.
 
Currently ND is working with MDE and the Maryland Environmental Service to obtain necessary permits for both the sediment characterization and dredging components of the pilot.  ND has completed a literature and data review of existing sediment and bathymetric data behind Conowingo Dam.  ND is also currently preparing a sampling and analysis plan to fully characterize the chemical and physical characteristics of Conowingo sediments. 
 
Once collected, this chemical and physical information will be used to categorize the dredged material according to MDE’s Innovative and Beneficial Reuse guidance to help determine environmentally safe reuse options.  ND will also be performing limited dredging of Conowingo sediments to test the different end uses of the dredged material consistent with this guidance.  Modeling tools are also being considered to simulate different dredging scenarios and their influence on Chesapeake Bay water quality.  The overall pilot project should be complete in 2020.  State partners on this pilot project include the Maryland Environmental Service, the Maryland Department of Natural Resources and the Maryland Geological Survey

Important Dates

The dredging portion of the pilot project will occur during winter 2020-2021. Approximately 1,000 cubic yards of sediment from the Maryland portion of the Susquehanna River will be mechanically dredged, dewatered on a barge, and stockpiled at a temporary staging area located at the Peach Bottom Road boat ramp at 101 Peach Bottom Road, Peach Bottom, Pennsylvania, 17563 (Lancaster County). The dredged material will then be removed for use at an approved innovative reuse and beneficial use project in Maryland and the boat ramp will be fully restored. The project will result in the complete closure of the Peach Bottom boat ramp between September 8, 2020 and February 28, 2021. This project will also result in the intermittent closure of Dorsey Park boat ramp at 1898 Lay Road, Delta, Pennsylvania 17314 (York County) during this timeframe to allow for mobilization and demobilization of equipment.

A recording is now available from the April 1, 2020 Public Information Meeting (please see the link at the bottom of this web page). Written comments will be due 30 days following the meeting (comment period ends May 1, 2020). For additional information or to provide comments contact Bill Buszinski (MES) at wbuszinski@menv.com​ or 259 Najoles Road, Millersville, MD 21108​.

Effective March 15, 2020 – Public Notice Opened for MDE 's Nontidal Wetlands and Waterways Permit. Written comments, requests to be included on the interested persons list, or requests for a public hearing may be sent by April 16, 2020 to the Maryland Department of The Environment, Attn: William Seiger, Chief, Waterway Construction Division, 1800 Washington Boulevard, Baltimore, MD 21230 or at William.seiger@maryland.gov​ or 410-537-3821. Any further notices concerning actions on the application will be provided only by mail to those persons on the interested persons list. Please refer to Subsection 5-907 of the Annotated Code of Maryland or the Code of Maryland Regulations 26.17.04 for information regarding the application process.   

April 1, 2020 –  WEBINAR