Below is a brief overview of the Federal Energy Regulatory Commission (FERC) relicensing process for the Conowingo dam
2025
November 25, 2025 – The Coalition provided notice to FERC of the administrative appeal filed with MDE on Nov 14. The letter sets forth some of the procedural and legal issues with the revised WQC issued by MDE on October 2, 2025.
Letter to FERC regarding Administrative Appeal of MDE Revised WQC available here
November 14th, 2025 – The CCC filed an administrative appeal to the Maryland Department of Environment (MDE) Revised Water Quality Certification (No. 17-WQC-02) issued to Constellation on October 2nd, 2025. The appeal cites major procedural failures and substantive weakening of protections required under the 2018 WQC.
CCC Administrative Appeal to MDE 2025 Revised Water Quality Certification available here
Comparison Table outlining the major differences between the 2018 WQC and 2025 Revised WQC
October 17th, 2025 – MDE publishes notice of the issuance of the Revised WQC in the MD Register, triggering a 30-day appeal window per COMAR; the notice references a Public Notice posted in July 2017, and a Public Hearing held in December 2017, to bypass COMAR requirements for this Revised Certification, by referencing the 2018 WQC as an “initial decision” when it was in fact issued as a final decision. See excerpt from Maryland Register below.
MD Register Issuance Notice of Revised WQC
October 13th, 2025 – MDE, Exelon and Waterkeepers jointly submit Revised WQC and Settlement Agreement to FERC.
October 2nd, 2025 – MDE issues a Revised WQC, announced via a press event with Exelon & Governor Moore.
Revised 2025 WQC available here
See Video “Conowingo Dam Agreement” Presser by MDE, announcing settlement
September 26th, 2025 – MDE, Exelon and Chesapeake Waterkeepers sign a secret settlement valued at $340M. Counties not notified.
2025 Settlement available here:
2024
April, 2024 – Confidential negotiations and mediation begins between MDE, Exelon, Waterkeepers Chesapeake and the Lower Susquehanna River Association
2023
August 1, 2023 – CCC submitted a comment letter to MDE during the limited public comment period on MDE’s reconsideration of the April 27, 2018 Water Quality Certification following remand. CCC and its member counties reaffirm their support for the original 2018 WQC as the minimum necessary conditions for relicensing, emphasize the “Conowingo factor” as a major obstacle to achieving Chesapeake Bay TMDL goals, call for adaptive management and reopener provisions in any license and request public hearings as part of MDE’s reconsideration process.
CCC Letter to MDE regarding Conowingo WQC Reconsideration Post Remand
June-August 2023 – MDE reopens reconsideration; invites public comments
Conowingo Hydroelectric Project – Section 401 WQC Reconsideration Fact Sheet
MDE Public Notice Announcement
Reconsideration Restart Letter
2022
In Waterkeepers Chesapeake v. FERC, the U.S. Court of Appeals for the D.C. Circuit vacated the FERC license issued to the Conowingo dam in 2021. The Court held that FERC violated Section 401 of the Clean Water Act by issuing a license based on Maryland’s attempted “conditional waiver” of the 2018 Water Quality Certification contained in the 2019 settlement agreement with Constellation. The Court ruled that Section 401 allows waiver only when a state “fails or refuses to act,” and that Maryland had clearly acted when it issued the 2018 WQC. Because FERC had no authority to disregard the 2018 WQC or rely on a retroactive waiver, the 50-year license was vacated and remanded so that the original administrative and judicial review of the 2018 WQC could resume. The Court noted that FERC may issue interim annual licenses during the remand.
2021
On March 18th 2021, without any prior public discussion, FERC approved Exelon’s Conowingo relicensing for the next 50 years which includes the 2019 settlement agreement between the Maryland Department of the Environment (MDE) and Exelon. This license was later vacated by the U.S. Court of Appeals in 2022 and remanded to FERC. It is no longer in effect.
This is the FERC News Release: FERC Relicenses Conowingo Hydroelectric Project
2020
CCC files formal comments with FERC urging stronger conditions
2019
October 29, 2019 – Governor Hogan announced that a settlement valued at $200M had been reached with Exelon Generation regarding the Water Quality Certification. Counties were excluded.
March 29, 2019 – the CCC filed another Motion to Intervene in the Petition for Declaratory Order by Exelon Generation now pending before FERC. This settlement later became the basis for the “waiver” argument adopted by FERC in 2021, but this position was rejected by the D.C. Circuit in 2022.
2018
On April 27th, 2018, MDE issued a robust, science based WQC valued at $7B over 50 years. The CCC supported it, while Exelon and Waterkeepers appealed it. Below is the 2018 WQC issued by MDE.
In October 2018, a Baltimore Court dismissed the first of the suits filed by Exelon.
Governor Hogan’s response can be found here.
On October 17, 2018, MDE filed a Notice of Supplemental Authority with an Exhibit. Exelon responded on October 24th.
Exelon chose to respond to the Maryland Department of the Environment’s (MDE) Water Quality Certification (WQC) with a storm of litigation. In addition to the letter itself, we have provided links to Exhibit A: Complaint in the U.S. District Court, Exhibit B: Administrative Appeal to MDE and Exhibit C: Complaint for Mandamus in Baltimore City Circuit Court.
2013
In June of 2013, the Coalition, on behalf of each of the Maryland counties that serve as its members, filed its Motion to Intervene in the relicensing application process associated with the Exelon’s Conowingo Dam Hydroelectric Project.
2010
In the 2010 TMDL, the United States Environmental Protection Agency (EPA) estimated that the Conowingo Reservoir trapped 55% of the phosphorus and sediment that flowed down the Susquehanna River. That assumption was incorrect and unsupported by the studies carried out by the United States Geological Survey (USGS) scientists upon whom the EPA relied to make its erroneous trapping assumption. One such study, Sediment Transport and Capacity Change in Three Reservoirs, Lower Susquehanna River Basin, Pennsylvania and Maryland 1900 – 2012, was especially significant in that it confirms the magnitude of the impact that power projects have on the natural and human environment. The Conowingo Reservoir is no longer a significant trap of phosphorus or sediment; the sediments are flushed into the Bay from the Susquehanna River and scoured from the Conowingo Dam reservoir. They are detrimental to the State’s fiscal health by having direct negative effects on local shoreline communities and their economies, as well as the multi-million dollar price tag associated with the dredging and maintenance of the polluted sediments.
In determining the sediment and nutrient loading from the Susquehanna River Basin, there exists another critical scientific fact that both EPA and MDE have overlooked; toxic levels of both nitrogen and phosphorus have bound to the sediments that have been deposited into the lakes and reservoir above the Conowingo Dam. These nutrients are inert, meaning they stay bound to the sediments, while the sediments stay behind in the reservoir and lakes above the Conowingo Dam. However, once those sediments are transported and churned through the Dam and into the Bay, changes in water temperature, pH, salinity and the level of dissolved oxygen cause the nutrients bound to the sediments to be quickly dispersed into the Bay, despite the fact that such nutrients were not released into the water while they remained in the Susquehanna River. The end result is that tremendous damage is caused to the Bay because these sediments were not subject to any dredging or other cleanup while they remained stagnant in the reservoir above the Dam.
Other CCC Advocacy in the FERC Process
Letter to MDE re: Section 401 WQC Application
August 16, 2017
Letter to FERC re: Exelon’s WQC Withdrawal
March 4, 2016
Letter to FERC re: the USGS Sediment Transport Report
February 24, 2015
Letter to FERC re: US EPA Request for Inclusion of Draft LSRWA Report
January 6, 2015
Notice of CCC Staff Attendance at MDNR Meeting
November 6, 2013
Letter to FERC re: Exelon’s Extension Request
August 23, 2013
Response to FERC’s June 13, 2013 Letter
June 18, 2013
FERC’s Response to Coalition’s April 4, 2013 Correspondence
June 13, 2013
Response to FERC’s Reply re: Meeting
April 14, 2013
FERC Denial of CCC Meeting Request
March 29, 2013
Letter to FERC re: Meeting Request
February 22, 2013