# WM Pacific Northwest — Hazardous Materials Safety Interpretation **Citation:** 22-0139 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2023-08-24 22-0139 response to WM Pacific Northwest concerning 172.504, 172.508, 172.516. ## Document text <<>> U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration August 24, 2023 Haydon Morris Transportation & Logistics Manager WM Pacific Northwest 720 4th Avenue, Suite 400 Kirkland, WA 98033-8136 Reference No. 22-0139 Dear Mr. Morris: This letter is in response to your December 19, 2022, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) regarding the requirements for visibility and display of placards on “half high” intermodal containers loaded with hazardous waste that move on “well cars” by rail. Specifically, you ask whether—in the event that “half high” (5-ft. tall) intermodal container placards are not visible when placed in a “well car”—does the well car itself need to be placarded on all four sides. The answer is yes. Generally, in accordance with § 172.504(a), each bulk packaging, freight container, unit load device, transport vehicle, or rail car containing any quantity of a hazardous material must be placarded on each side and each end. For rail transportation, § 172.508(a) allows placards displayed on a transport container to satisfy the requirements for affixing placards on a rail car. However, in this scenario, the placards on the “half high” intermodal containers in the rail car (i.e., well car) will not be visible and therefore, both the intermodal containers and the rail cars must be placarded. Furthermore, § 172.516(a) states that each placard on a rail car must be clearly visible from the direction it faces, except from the direction of another rail car to which the rail car is coupled. Therefore, in a scenario such as this where the “half high” intermodal container placards are not visible when placed in a well car, the well car placards must be displayed so that they are clearly visible from the direction it faces—except from the direction of another rail car to which it is coupled. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, 1200 New Jersey Avenue, SE Washington, DC 20590 Dirk Der Kinderen Chief, Standards Development Branch Standards and Rulemaking Division <<>> Cardez 2-0139 From: INFOCNTR (PHMSA) To: Date: Dodd, Alice (PHMSA); Hazmat Interps Subject: FW: Request For Interpretation Wednesday, December 21, 2022 9:08:10 AM Hi Alice and team, Please see the LOI request below. Thank you. -Rachel (HMIC) From: Morris, Haydon Sent: Monday, December 19, 2022 5:47 PM To: INFOCNTR (PHMSA) Subject: Request For Interpretation CAUTION: This email originated from outside of the Department of Transportation (DOT). Do not click on links or open attachments unless you recognize the sender and know the content is safe. Good Afternoon, We are looking for clarification on placard requirements when it comes to hazardous waste loaded into half high intermodal containers that move on well cars via railroad. Within our operation, these containers carrying haz waste have placards on all 4 sides and move over the road to Union Pacific Rail Yard in Seattle where they have been loaded on rail cars for final transport to our Landfill in Arlington, Oregon. Please confirm the following: In the event these half high (5ft tall) intermodal container placards are not visible when placed in the well car, does the well car itself need to have placards on all 4 sides to keep within DOT regulation in addition to the container with hazardous material? WM and UP had been operating under the pretense it was acceptable to placard the wells in these instances but ODOT continues to advise this is not acceptable. Thanks, Haydon Morris Transportation & Logistics Manager Pacific Northwest hmorris@wm.com 720 4th Avenue, Suite 400 Kirkland, WA 98033-8136 <<>> Access WM 24/7 with MyWM Recycling is a good thing. Please recycle any printed emails. ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `c33a4e8064bad4da5b07c2c396af9ed99eb934e4328427055e1e6b16f0891ee6` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T17:28:14.895Z - Document slug: `phmsa-interpretation-22-0139` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "WM Pacific Northwest" ], "individuals": [ "Haydon Morris" ], "refIds": [ "22-0139" ], "catalogDates": [ "2023-08-24" ], "catalogParts": [ 172 ], "catalogRowCount": 3, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/73771" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "172.504", "172.504(a)", "172.508", "172.508(a)", "172.516", "172.516(a)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/172504", "https://www.phmsa.dot.gov/regulations/title49/section/172508", "https://www.phmsa.dot.gov/regulations/title49/section/172516" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-05/220139.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-05/220139.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-05/220139.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/22-0139-4bbd571b45.pdf", "pdfArtifactSha256": "59350746518439c54fcb8e05b4761453b1a0dfe9c265066495bde11ebafd39eb", "extractedTextPath": "data/sources/phmsa-interpretations/22-0139-4bbd571b45.v2.txt", "extractedTextSha256": "f11b7b5555f71b34fc6a197b7e98e43f314a2fe1ef9f4ffa97000b160c93bca8", "pageCount": 3, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```