43 CFR § 3162.2-10
Will BLM notify me when it determines that drainage is occurring?
June 11, 2020
We will send you a demand letter by certified mail, return receipt requested, or personally serve you with notice, if we believe that drainage is occurring. However, your responsibility to take protective action arises when you first knew or had constructive notice of the drainage, even when that date precedes the BLM demand letter.
[66 FR 1894, Jan. 10, 2001]