49 CFR §190.11

1. (a)Availability of telephonic and Internet assistance. PHMSA has established a Web site and a telephone line to OPS headquarters where information on and advice about compliance with the pipeline safety regulations specified in 49 CFR parts 190-199 is available. The Web site and telephone line are staffed by personnel from PHMSA's OPS from 9:00 a.m. through 5:00 p.m., Eastern Time, Monday through Friday, with the exception of Federal holidays. When the lines are not staffed, individuals may leave a recorded voicemail message. The telephone number for the OPS information line is (202) 366-4595 and the OPS Web site can be accessed via the Internet at http://phmsa.dot.gov/pipeline.
2. (b)Availability of written interpretations. A written regulatory interpretation, response to a question, or an opinion concerning a pipeline safety issue may be obtained by submitting a written request to the Office of Pipeline Safety (PHP-30), PHMSA, U.S. Department of Transportation, 1200 New Jersey Avenue SE., Washington, DC 20590-0001. The requestor must include his or her return address and should also include a daytime telephone number. Written requests should be submitted at least 120 days before the time the requestor needs a response.
3. (c)Public notice of interpretations. Each request for written interpretation will be made available to the public on the PHMSA website with an opportunity to submit comment for a period not to exceed 30 days. PHMSA will consider the public comments received and may, in its discretion, respond to any comment. Each final written interpretation will be posted to the PHMSA interpretations website.