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Maryland Department of the Environment

Department of the Environment extends public comment period on Water Quality Certification application for proposed Conowingo Dam relicensing

Media contact: Jay Apperson


Department of the Environment extends public comment period on Water Quality Certification application for proposed Conowingo Dam relicensing

Applicant Exelon must show project will comply with state water quality standards and requirements; public hearing to follow public comment period

BALTIMORE (Aug. 8, 2017) – The Maryland Department of the Environment is extending by two weeks the public comment period on the Proposed Relicensing of the Conowingo Hydroelectric Project Application for Water Quality Certification under the Clean Water Act.

In July, the department issued public notice to solicit comments from the public and state the department’s intention to hold a public hearing in the fall. To allow and encourage further public participation and input, the department is extending the public comment period from Aug. 9 to Aug. 23. The department will reopen the public comment period at the time of the hearing and may reopen the public comment period in the event that additional information becomes available which it determines should be subject to review and comment.

Under federal law and as part of the Federal Energy Regulatory Commission’s relicensing process, the applicant, Exelon Generation Company LLC, is required to obtain a Clean Water Act, Section 401 Water Quality Certification from the Maryland Department of the Environment for the continued operation of the facility. Issuance of a Water Quality Certification is contingent upon the applicant demonstrating to the department that the project will comply with State water quality standards and requirements.

Science has demonstrated that the Conowingo Dam has essentially lost its capacity to trap sediment and phosphorus, and if it’s not addressed Chesapeake Bay cleanup goals will likely not be met. Governor Larry Hogan convened a second Conowingo Dam Summit today to share proposed solutions.

“Maryland will use all available tools, including a potential veto under the federal Clean Water Act, to protect the Susquehanna River and Chesapeake Bay in the relicensing of the Conowingo Dam,” said Maryland Environment Secretary Ben Grumbles. “We look forward to working with Exelon and many other partners in the coming weeks.”

In 2014, in response to Exelon’s initial application for Water Quality Certification, the Maryland Department of the Environment stated its intent to deny the application due to insufficient information provided by the applicant regarding the water quality impacts of the proposed activity. In recognition of that position, Exelon withdrew its application and agreed to provide up to $3.5 million for further study of the effects of sediment and associated nutrients on the water quality of the lower Susquehanna River and the Chesapeake Bay.

Last July, Governor Hogan held an inaugural Conowingo Dam Summit and announced the formation of a multi-agency workgroup to seek innovative solutions for reducing pollution that threatens the Chesapeake Bay. The Hogan administration also announced a formal Request for Information to help find solutions and determine if dredging of the Conowingo Dam and re-use of dredged materials can be done in an efficient and effective way. In March, the Department of the Environment, in collaboration with the Maryland Department of Transportation’s Port Administration, issued draft guidelines for reuse of dredged material in innovative ways that protect and benefit the environment and public health.

In May, Exelon submitted the current application for Water Quality Certification for the dam’s relicensing. As part of its review, the Maryland Department of the Environment, in close coordination with the Department of Natural Resources and other agencies, will identify all applicable water quality standards and requirements and utilize data, modeling and further scientific analysis, along with materials provided by Exelon and information provided in public comments, to determine wheter the operation of and discharges from the Conowingo Hydroelectric Project will comply with all applicable Maryland water quality standards and requirements, including those downstream, in the Chesapeake Bay. The department has until mid May 2018 to complete its review.

The public is invited to submit written comments on the water quality impacts of the project. Comments may be submitted to: Elder Ghigiarelli Jr. Deputy Program Administrator, Wetlands and Waterways Program, Water Management Administration, Maryland Department of the Environment, 1800 Washington Boulevard, Suite 430, Baltimore, MD 21230 or by email to

Subsequent to the close of the comment period, the department intends to hold a public hearing on the application in the fall. A public notice announcing the hearing will be published in the Maryland Register, placed on the department’s website and mailed to those on the Wetlands and Waterways Program interested persons list.

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