10. Charges for the use of water not paid within the prescribed time bear interest, from the date of default, at the rate determined under the first paragraph of section 28 of the Tax Administration Act (chapter A-6.002).
In addition to the interest payable, the following amounts are added to every amount outstanding:
(1) 7% of the amount of the unpaid charges if the delay does not exceed 7 days;
(2) 11% of the amount of the unpaid charges if the delay exceeds 7 days but does not exceed 14 days;
(3) 15% of the amount of the unpaid charges in all other cases.