B-1.1, r. 3 - Safety Code

Full text
145. The owner must conduct leak detection tests on underground tanks and piping in accordance with the second paragraph of section 8.130 of Chapter VIII of the Construction Code (chapter B-1.1, r. 2) each time one of the following occurs inexplicably:
(1)  a volume loss of at least 0.5% of the petroleum products removed from a tank or a number of tanks containing the same product over a period of 1 month;
(2)  a loss of petroleum products over at least 5 consecutive days;
(3)  a loss of petroleum products over at least 18 days in a month, if the product level is measured every day;
(4)  a loss or gain of petroleum products over at least 15 days in one month, if the product level is measured 6 days a week; or
(5)  the water level in the bottom of the tank exceeds 50 mm.
If the leak detection test indicates a leak, all defective components in the installation must be repaired or replaced and another leak detection test must be conducted.
O.C. 221-2007, s. 1.