10/10/2025 | Press release | Distributed by Public on 10/10/2025 09:16
PUBLIC NOTICE
Draft Air Quality Permit 6663-R1, Architect of the Capitol, Operation of an existing 7.5 MW dual fuel-fired (natural gas and No. 2 fuel oil cogeneration system at the U.S. Capitol Power Plant, 25 E Street SE, Washington DC
Notice is hereby given that, pursuant to 20 DCMR § 210, the Air Quality Division (AQD) of the Department of Energy and Environment (DOEE), located at 1200 First Street NE, 5th Floor, Washington DC, proposes to issue air quality permit No. 6663-R1 to the Architect of the Capitol (AOC) to operate an existing cogeneration system that consists of a 78.4 MMBTU/hr combustion turbine with an associated heat recovery steam generator (HRSG) with duct burners with a heat input rating of 71.9 MMBTU/hr when burning natural gas and 68.3 MMBTU/hr when burning diesel oil, at the U.S. Capitol Power Plant (CPP), 25 E Street SE, Washington DC 20003. The contact person for facility is Christopher Potter, Director, Utilities and Power Plant Operations, at (202) 641-6651 or [email protected].
Emissions Estimates:
The maximum potential to emit air pollutants from the cogeneration system has been estimated to be as follows:
Pollutants |
Potential to Emit |
Total Particulate Matter (PM Total)1 |
11.4 |
Carbon Monoxide (CO) |
47.8 |
Carbon Dioxide (CO2e) |
79,150.6 |
Hexane (C6H14)2 |
0.51 |
Oxides of Nitrogen (NOx) |
59.2 |
Sulfur Dioxide (SO2) |
4.2 |
Volatile Organic Compounds (VOC) |
6.7 |
Total Hazardous Air Pollutants (HAPs) |
0.9 |
Emission Limitations:
The proposed emission limits for the equipment are as follows (from Condition II of the permit):
a. No discharge of gases to the atmosphere which contain SO2 in excess of one hundred ten (110) ng/J gross output, equivalent to 0.90 lb/MWh; or
b. No fuel may be burned which contains total potential sulfur emissions in excess of twenty-six (26) ng SO2/J heat input, equivalent to 0.060 lb SO2/MMBTU.
a. When burning exclusively natural gas, twenty percent (20%); and
b. When burning fuel oil or a combination of fuel oil and natural gas, twenty seven percent (27%).
Violation of the requirements of this condition that occur as a result of unavoidable malfunction, despite the conscientious employment of control practices, shall be an affirmative defense for which the Permittee shall bear the burden of proof. A malfunction shall not be considered unavoidable if the Permittee could have taken, but did not take, appropriate steps to eliminate the malfunction within a reasonable time, as determined by the Department. [20 DCMR 903.13(b)]
Note: This condition is District enforceable only.
The permit application and supporting documentation, along with the draft permit are available for public inspection at AQD and copies may be made available between the hours of 9:00 A.M. and 5:00 P.M. Monday through Friday. Interested parties wishing to view these documents should provide their names, addresses, telephone numbers and affiliation, if any, to Stephen S. Ours at (202) 498-8143 or [email protected].
Copies of the draft permit and related technical support memorandum are also available at in the attachments section below.
Interested persons may submit written comments or may request a hearing on this subject within 30 days of publication of this notice. The written comments must also include the person's name, telephone number, affiliation, if any, mailing address, and a statement outlining the air quality issues in dispute and any facts underscoring those air quality issues. All relevant comments will be considered before taking final action on the permit application.
Comments on the proposed permit and any request for a public hearing should be addressed to:
Stephen S. Ours
Chief, Permitting Branch - Air Quality Division
Department of Energy and Environment
1200 First Street NE, 5th Floor
Washington DC 20002
No comments or hearing requests submitted after November 10, 2025 will be accepted.
For more information, please contact Stephen S. Ours at (202) 498-8143.