PUBLIC NOTICE

Draft Air Quality Permits 5319-R1, 7408, 7409, and 5622-R1 for the Architect of the Capitol 
to Operate Four Existing 60 MMBTU/hr Boilers at the U.S. Capitol Power Plant with Proposal to 
Incorporate Certain Permit Requirements into the District’s State Implementation Plan (SIP)

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 Nos. 5319-R1, 7408, 7409, and 5622-R1 to the Architect of the Capitol (AOC) to operate four identical existing 60 MMBTU/hr dual fuel (natural gas and No. 2 commercial fuel oil) boilers, designated Boilers 4, 5, 6, and 7, 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) 226-3864 or [email protected].

In addition to standard permit issuance, with this action, DOEE is proposing to submit, to the U.S. Environmental Protection Agency (EPA), the requirements contained in Conditions II(a) and (b) (emission limits) and III(b) (limits on fuel usage) of the draft permit for inclusion in the District’s State Implementation Plan (SIP), located at 40 CFR Part 52, Subpart J. DOEE is proposing to include the requirements of these permit conditions in the SIP in order to ensure federal enforceability of the alternative Reasonably Available Control Technology for Oxides of Nitrogen (NOx RACT) Plan, dated August 2024, submitted by AOC pursuant to 20 DCMR § 805.2. Comments on this plan were previously taken pursuant to a public notice posted in the D.C. Register (Vol. 72 – No. 17, 005234– 005235) and on the Department’s website (https://doee.dc.gov/release/alternativenoxract2) on April 25, 2025. DOEE has not finalized an evaluation of the comments received in response to that action, the resolution of which may be considered in the resolution of this permitting action as well.

Emissions Estimates:

The maximum potential to emit air pollutants from each of Boilers 4 through 7, under the fuel usage limitations contained in the draft permit, has been estimated to be as follows:

These emissions estimates for each pollutant are based on the worst case of operating fully on natural gas or operating fully on No. 2 fuel oil.

Emission Limitations:

The proposed emission limits for the equipment are as follows (from Condition II of the draft permit):

a.   Oxides of nitrogen (NOx) emissions from the west stack shall not exceed 0.14 pound per million BTU (lb/MMBTU) when burning natural gas, No. 2 fuel oil, or any combination thereof in any combination of Boilers 3 through 7, as determined on a 30-day rolling average basis. This limit shall apply at all times including periods of startup, shutdown, or malfunction any boiler. [20 DCMR 805.2] 

This limit adopts an alternative RACT standard pursuant to 20 DCMR 805.2 and will be submitted to EPA for inclusion in the District’s State Implementation Plan (SIP) at 40 CFR 52, Subpart J.

b.   NOx emissions from the west stack shall not exceed either of the following [20 DCMR 805.2]:

    1.   0.30 lb/MMBTU, based on a 2-hour average; or

    2.   0.25 lb/MMBTU, based on a calendar day average.

This limit adopts an alternative RACT standard pursuant to 20 DCMR 805.2 and will be submitted to EPA for inclusion in the District’s State Implementation Plan (SIP) at 40 CFR 52, Subpart J.

c.   Carbon monoxide (CO) emissions from each unit shall not exceed the following [20 DCMR 201]:

    1.   When burning fuel oil exclusively, 0.0365 lb/MMBTU; and

    2.   When burning natural gas or a combination of fuel oil and natural gas, 0.0824 lb/MMBTU.

d.   Except as specified below, visible emissions whose opacity is in excess of ten percent (10%) (unaveraged), at any time shall not be permitted into the outdoor atmosphere. This visible emissions standard shall apply at all times, except that discharges shall be permitted for two (2) minutes during any startup, cleaning, adjustment of combustion or operational controls, or regeneration of emission control equipment; provided that such discharges shall not exceed the following opacities (unaveraged): [20 DCMR 606.1 and 606.2]

1. When burning exclusively natural gas, twenty percent (20%); and
    
2. When burning fuel oil or a combination of fuel oil and natural gas, twenty-seven percent (27%).

e.   Total particulate matter emissions (total filterable plus condensables) from each of these boilers shall not be greater than the following [20 DCMR 201 and 20 DCMR 600.1]:

    1.   When burning exclusively natural gas, 0.0075 lb/MMBTU; and

    2.   When burning fuel oil or a combination of fuel oil and natural gas, 0.024 lb/MMBTU 

Note that this is a streamlined permit condition. Compliance with this standard, established in accordance with the permit application and 20 DCMR 201, will ensure compliance with the total suspended particulate matter (TSP) standard for filterable particulate only, specified in 20 DCMR 600.1.

f.    An emission into the atmosphere of odorous or other air pollutants from any source in any quantity and of any characteristic, and duration which is, or is likely to be injurious to the public health or welfare, or which interferes with the reasonable enjoyment of life or property is prohibited. [20 DCMR 903.1] 

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 owner or operator shall bear the burden of proof. A malfunction shall not be considered unavoidable if the owner or operator 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.

g.   In addition to complying with the requirements of this permit document, the Permittee shall comply with all Plantwide Applicability Limits (PALs) established for the facility. 

Additional Alternative NOx RACT Limit

In addition to Conditions II(b) and (c) listed above, the following Condition III(b) of the draft permit is proposed for inclusion in the District’s SIP at 40 CFR 52, Subpart J:

h.   The consumption of fuel, from each of boilers 4 through 7, on a 12-consecutive-month rolling sum basis, shall be limited to a total, combined heat input of all fuels of 215,000 MMBTU. [20 DCMR 201 and 20 DCMR 805.2]:

Note:  This condition adopts an alternative RACT standard pursuant to 20 DCMR 805.2 and will be submitted to EPA for inclusion in the District’s State Implementation Plan (SIP) at 40 CFR 52, Subpart J.

The permit applications 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 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

[email protected]

No comments or hearing requests submitted after November 23, 2026 will be accepted.

For more information, please contact Stephen S. Ours at (202) 498-8143.