Notice of Public Comment Period – Draft Source Category Permit 7123-SC-R2

PUBLIC NOTICE

Proposed Air Quality Permit 7123-SC-R2 – Source Category Permit to Construct and Operate Temporary Portable Concrete Plants  at various locations in the District of Columbia

Notice is hereby given that, pursuant to 20 DCMR §§200 and 210, the Air Quality Division (AQD) of the Department of the Energy and Environment (DOEE), located at 1200 First Street NE, 5th Floor, Washington, DC, proposes to issue a source category permit modification and renewal to operate temporary portable concrete plants in the District of Columbia. This source category permit will be designated Permit No. 7123-SC-R2.

To ensure that certain regulatory limits are not exceeded and that more complex or potentially controversial projects of this type are subject to case-by-case permitting, a number of limitations have been established on the applicability of this source category permit, including limiting the duration of the operation at the site to two years total, limiting operating hours to eight hours per day, limiting the size of the equipment, and limiting the total production of the equipment. Additionally, in some cases such equipment is powered by non-emergency engines. This permit has been written to authorize the use of generators powered by model year 2007 and newer diesel engines up to 300 brake horsepower in gross power output.

Applicants who apply for coverage under a source category permit must document that their equipment meets the applicability criteria specified in the permit prior to approval of coverage and authorization to operate the unit under the authority of the source category permit.

The proposed emission limits to be included in the permit are as follows:

1. Emissions of dust shall be minimized in accordance with the requirements of 20 DCMR 605 and the “Operational Limitations” of this permit.
2. The emission of fugitive dust from any material handling, screening, crushing, grinding, conveying, mixing, or other industrial-type operation or process is prohibited. [20 DCMR 605.2]
3. The discharge of total suspended particulate matter (TSP) into the atmosphere from any process shall not exceed three hundredths (0.03) grains per dry standard cubic foot of the exhaust. [20 DCMR 603.1]
4. The discharge of TSP from the portable concrete plant shall not exceed 40 pounds per hour. [20 DCMR 603.1 and Appendix 6-1]
5. Emissions of PM10 shall be less than 15 tons in any consecutive 12-month period. [20 DCMR 204]
6. Any diesel engine used to power the plant shall be certified to the certification emission standards for new nonroad compression ignition (CI) engines in 40 CFR 1039.101. 40 CFR 2039.102, 40 CFR 1039.104, 40 CFR 1039.105, 40 CFR 1039.107, 40 CFR 1039.115, and 40 CFR 1039, Appendix I, as applicable for all pollutants for the same model year and maximum engine power, and shall comply with such standards. Should testing for compliance be required, such testing shall be performed pursuant to the applicable test methods in 40 CFR 1039, Subpart F. [40 CFR Subpart IIII, 40 CFR 60.4204(b), 40 CFR 60.4201(a)].
7. Visible emissions shall not be emitted into the outdoor atmosphere from any part of the equipment, including the main plant, any boiler, or any engine, except that discharges shall be permitted for two (2) minutes during any start-up, cleaning, adjustment of combustion or operational controls, or regeneration of emissions control equipment; provided, that such discharges shall not exceed the following [20 DCMR 606.1 and 606.2(a), (d), and (f)]:

a. Twenty percent (20%) opacity (unaveraged) from any boiler burning exclusively natural gas; and

b. Twenty-seven percent (27%) opacity (unaveraged) from all other equipment covered by this permit.

8. 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 Permittee shall bear the burden of proof. A malfunction should 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.

Emissions Estimate:

Operational limits have been put in place to limit potential emissions of particulate matter and other pollutants from the equipment to ensure compliance with various regulations. Some concrete plants operate small hot water heaters/boilers. Some also operate non-emergency generator sets to power the concrete plant. The limits placed on the size and operating hours of these units are expected to ensure that emissions from these units do not exceed thos specified in the following table:

The draft permit and supporting documentation 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 June 15, 2026 will be accepted.

For more information, please contact Stephen S. Ours at (202) 498-8143 or [email protected]