§ 494.
If any operation or maintenance charge is unpaid on the 1st day of the third calendar month after it became due a penalty of 1 per centum of the amount unpaid shall be added thereto, and thereafter an additional penalty of one-half of 1 per centum of the amount unpaid shall be added on the 1st day of each calendar month if such charge and penalties shall remain unpaid.
([Aug. 13, 1914, ch. 247, § 6], [38 Stat. 688]; [Dec. 5, 1924, ch. 4, § 4], subsec. H, [43 Stat. 703].)