Storage Tank Systems for Petroleum Products and Allied Petroleum Products Regulations

19 (1) The owner or operator of a storage tank system installed before June 12, 2008 that has horizontal aboveground tanks without secondary containment must visually inspect the walls of those tanks within two years after June 12, 2008 to determine if the tank is leaking and after that inspection they must

• (a) visually inspect the walls of those tanks at least once per month and perform an inventory reconciliation in accordance with subsection (2);

• (b) immediately

  • (i) use continuous in-tank leak detection in accordance with section 20, or

  • (ii) use continuous external horizontal aboveground tank leak monitoring; or

• (c) annually perform a tank precision leak detection test in accordance with section 21.

(2) The inventory reconciliation must include

• (a) the measurement of the level of water and the combined level of water and petroleum product or allied petroleum product in every storage tank of the storage tank system at least every seven days unless the storage tank system is located at a fuel dispensing station, in which case the levels must be measured each day the station is in operation; and

• (b) a comparison of the measurements with readings of any meters that measure the volume of liquid transferred and the calculation of any gain or loss of liquid each time the measurements are taken.

(3) The continuous external horizontal aboveground tank leak monitoring must

• (a) be carried out using a sensor cable system designed for installation beneath the horizontal aboveground tank and surrounding its perimeter dripline in order that any leak will be detected before any liquid moves beyond the tank’s perimeter;

• (b) be capable of detecting a leak rate of at least 0.38 L/h within 30 days after the onset of the leak at the lowest expected air temperature at the site where the sensor cable system is installed;

• (c) be capable of locating the leak with an accuracy of ± 1 m;

• (d) be capable of continuously monitoring sensor cable system integrity; and

• (e) have an alarm located at a place of work where it can be readily heard and seen.