Section 107.309 - Warning letters(a) The Associate Administrator may issue a warning letter to any person whom the Associate Administrator believes to have committed a probable violation of the Federal hazardous material transportation law, the Federal Water Pollution Control Act, or any provision of this subchapter, subchapter B of this chapter, subchapter C of this chapter, or any special permit issued thereunder. (b) A warning letter issued under this section includes:(1) A statement of the facts upon which the Associate Administrator bases its determination that the person has committed a probable violation;(2) A statement that the recurrence of the probable violations cited may subject the person to enforcement action; and(3) An opportunity to respond to the warning letter by submitting pertinent information or explanations concerning the probable violations cited therein.Amdt. 107-11, 48 FR 2651, 1/20/1983, as amended by Amdt. 107-15, 51 FR 34986, 10/1/1986; Amdt. 107-24, 56 FR 8621, 2/28/1991; Amdt. 107-32, 59 FR 49131, 9/26/1994; Amdt. 107-36, 61 FR 7183, 2/26/1996; 66 FR 45377, 8/28/2001; 84 FR 6947, 4/1/2019