D.C. Mun. Regs. tit. 20, § 903 – Odorous or Other Nuisance Air Pollutants

903 ODOROUS OR OTHER NUISANCE AIR POLLUTANTS

903.1 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 and property is prohibited.

903.2 Any stationary source that falls within the following categories regulated by the District of Columbia Air Pollution Control Act of 1984 (the “Act”), effective March 15, 1985 (D.C. Law 5-165; D.C. Official Code § 8-101.05) shall submit an Odor Control Plan (OCP):

(a) Cannabis cultivation centers and manufacturers of cannabis products, as described in D.C. Official Code § 7-1671.01 et seq., and any other cannabis cultivation, processing, or manufacturing operation required to be licensed under District law;
(b) Painting operations subject to the requirements of 20 DCMR § 718 or 1409;
(c) Trash transfer stations;
(d) Asphalt processing plants;
(e) Wastewater treatment facilities and systems; and
(f) Commercial solid fuel-fired cooking operations.

903.3 The Department may, through the issuance of an administrative order, require an owner or operator of a stationary source of odorous air pollutants, not required to operate under an OCP by § 903.2, to submit an OCP to the Department if:

(a) The source emits odorous air pollutants that are detected by a trained inspector using a field olfactometer when one (1) volume of odorous air has been diluted with two (2) or more volumes of odor-free air, as measured at a location or locations where it is likely odorous air pollutants will be detected given the prevailing atmospheric conditions; or
(b) The Department receives three (3) or more complaints about the source from distinct addresses within the District, which includes distinct units, apartments, or suites at a single street address, within a thirty (30) day period; provided, that:
(1) Each complainant submits a written statement, or a report to

DC311, containing the following information:

(A) The complainant's name, address, and business, if applicable;

(B) The date, time, duration, and description of the odor that the complainant detected; and

(2) The Department confirms that the odor identified in the complaints is coming from the suspected source.

903.4 (a) An owner or operator of a stationary source shall submit an OCP meeting the requirements of § 903.5 by the following deadlines:

(1) Within sixty (60) days of the issuance of an administrative order pursuant to § 903.3; or

(2) For a source that falls within the regulated categories described in § 903.2:

(A) Within ninety (90) days of August 4, 2023, if the source was constructed before that date; or

(B) At least sixty (60) days before commencing construction if the source is to be constructed after August 4, 2023, or with the source's permit application under 20 DCMR §§ 200.1 or 200.2, whichever is sooner.

(b) The Department may order submission of an OCP in a period other than the time periods defined in § 903.4 (a) on a case-by-case basis, upon consideration of the following factors:

(1) The severity of the odor;

(2) The number of distinct complainants;

(3) The frequency of complaints; and

(4) The amount of time needed by the source to develop the OCP.

903.5 An OCP shall contain requirements sufficient to control nuisance odors and shall include, to the extent applicable, the following information:

(a) Source information:

(1) Name of source;

(2) Name, phone number, and email address (if available) of source's owner or operator and point of contact;

(3) Source physical address;

(4) Source mailing address (if different from physical address);

(5) Source type;

(6) Source hours of operation;

(7) Description of source operations; and

(8) Emergency contact information;

(b) The following information about any odor generated by the source:

(1) Floor plan, specifying the locations of odor-emitting activity and emissions;

(2) Specific odor-emitting activity; and

(3) Phases (timing, length, etc.) of odor-emitting activity;

(c) A description of the proposed odor mitigation procedures and practices, which must either be based on industry-specific best control technologies and best management practices or be otherwise sufficient to effectively prevent nuisance odors for all odor sources, and which must include the following:

(1) Administrative controls:

(A) Maintenance, testing, and audit procedures to ensure that control equipment is functioning properly and the OCP is being adhered to;

(B) Staff training;

(D) Any other work practices necessary to prevent nuisance odors;
(2) A proposal concerning engineering controls sufficient to effectively mitigate odors for all odor sources, to address the following:
(A) Engineering controls shall include each of the following components:
1. (i) System design;
2. (ii) Operational processes; and
3. (iii) Maintenance plan; or
(B) If the owner or operator of a source determines that engineering controls are not necessary to effectively mitigate odors for all or specific odor sources, the owner or operator shall submit that determination to the Department as part of its OCP;
(d) A timeline for implementation of odor mitigation practices that takes into account the compliance time needed for the design, ordering, contracting, installation, and start-up of control equipment or process changes, commencing upon notice from the Department that it has approved the OCP; and
(e) A description of the source's procedures for receiving, responding to, and tracking complaints.903.6 The Department shall review the OCP and determine whether it meets the requirements of § 903.5:- (a) If the Department determines that the OCP meets the requirements of § 903.5, it shall approve the OCP and notify the source's owner or operator of the approval; or
(b) If the Department determines that the OCP does not meet the requirements of § 903.5, it shall disapprove the OCP and notify the source owner or operator in accordance with § 903.7.903.7 If the Department notifies a source's owner or operator that it has disapproved the OCP for that source, the Department shall provide a written description of the

reason(s) for the disapproval and the owner or operator shall:

(a) Submit modifications to the source's OCP to address the deficiencies within a period established by the Department; and

(b) Upon issuance of an order under § 106, which DOEE shall not issue for activities it determines to be essential for health and safety, cease nuisance-causing odor-emitting activities.

903.8 If the Department notifies a source's owner or operator that it has approved the OCP for that source, the owner or operator shall:

(a) Implement its OCP per the timeline it has provided under § 903.5(d); and

(b) Comply with the OCP, including any approved amendments, until the source has been decommissioned or otherwise ceases operations.

903.9 When a modification is made to a source, or to a process at the source, that has the potential to affect the nature or degree of odor or the control of odor, the owner or operator of the source must submit an update to its OCP within thirty (30) days of the modification. If the modification is subject to the requirements of 20 DCMR § 200, the owner shall submit an updated OCP as part of the source's permit application pursuant to that section.

903.10 Any owner or operator of a source that seeks a variance from the requirements of this section shall comply with the procedures under 20 DCMR § 103.

903.11 The owner or operator shall provide all records maintained pursuant to § 903.5(c)(1)(C) to the Department upon request.

903.12 The owner or operator shall report all deviations from the OCP to the Department within three (3) business days of the deviation;

903.13 Compliance with this section shall be determined as follows:

(a) Compliance with the OCP shall be an affirmative defense to violations of § 903.1 for which the owner or operator shall bear the burden of proof. However, in the event that the Department determines the OCP is inadequate to prevent violations of § 903.1, the Department may require the owner or operator to modify the OCP in accordance with the procedures under § 903.7.

(b) Violation of standards set forth in this section 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.

903.14 The Department may determine that the installation of odor control equipment or the change in a process identified in an OCP is not subject to the requirements of 20 DCMR § 200 to obtain a permit prior to installation and initial operation if:

(a) The Department determines that the installation of control equipment or change in process:

(1) Is designed to reduce or control odors at the source;

(2) Will not result in any non-negligible change to the emission of any non-odorous air pollutants;

(3) Is not inimical to public health and welfare; and

(4) Will not prevent attainment, nor interfere with maintenance, of any applicable national ambient air quality standard; and

(b) If not already submitted pursuant to § 903.9, the owner or operator of the source agrees to submit an application for a permit to operate, or to amend an existing permit to operate, the installed odor control equipment or change in a process pursuant to 20 DCMR § 200.2 no later than sixty (60) days after the Department's written determination under this subsection is issued.

SOURCE: Section 3 of the District of Columbia Air Pollution Control Act of 1984, D.C. Law 5-165, 32 DCR 565, 647 (February 1, 1985); as amended by §14 of the Solid Waste Facility Permit Act of 1995, D.C. Law 11-94, 42 DCR 7178 (December 29, 1995); as amended by Final Rulemaking published at 70 DCR 010830 (August 4, 2023); as amended by Final Rulemaking published at 72 DCR 007818 (July 11, 2025); as amended by Final Rulemaking published at 73 DCR 005904 (April 10, 2026).