Tank system regulations are found in the Alberta Fire Code, administered by Alberta Municipal Affairs. Site cleanup requirements are found in the “Risk Management Guidelines for Petroleum Tank Sites” and are administered by Alberta Environment.
Storage tank sites may be classified in one of two ways (Class A & B). Class A includes tanks within 500m of a water well, 200m of surface water, or 150m from a major underground structure (train station, parkade, etc). In addition, there are 23 municipalities where groundwater supplies would be particularly compromised by a storage tank leak and are given A classification. All other sites are B class.
Underground Storage System Minimum Requirements
- Cathodic Protection:
Steel tank and piping systems require cathodic protection (CP) in order to stop the system from externally corroding. The effectiveness of a CP system depends on a number of factors including the type, (whether it be sacrificial anode or impressed current), soil corrosiveness, choice of anode material and maintenance of the system. Impressed current CP systems must be designed and added to an existing system by a corrosion expert. A list of companies offering corrosion services is available here. - Tank Leak Detection:
Tank sites must have a method of doing monthly monitoring for releases from a tank. The Appendix of the Alberta Fire Code should be consulted for a expanded explanation of possible leak detection systems. Included as an option are monitoring wells, which are installed in the backfill around the tank(s). Also called piezometers, monitoring wells allow the tank operator to look for product on the surface of groundwater, or in the absence of groundwater, analyze vapors for hydrocarbon with a combustible gas indicator or color metric tubes. If your tanks have dual walls, monitoring the space between the walls is a simple and reliable leak detection procedure. If you have an automatic tank gauging system with a leak detection capability, leak tests can be conducted during quiet time. Statistical Inventory Reconciliation procedure qualifies as a leak detection method and is a relatively inexpensive method of satisfying the tank (and line) detection requirements. - Line Leak Detection:
The majority of leakage problems from underground systems are associated with product piping. The method of line leak detection depends on the style of your pumping system:a) Pressure Systems - If you pump product to a dispenser from the tank using a submersible pump you may use a pressurized pipe mechanical or electronic leak detector. If you have double-walled piping visual monitoring in the sumps is not sufficient. If a mechanical or electronic leak detector is not used then sensors in the sumps must be utilized.
b) Suction Systems – Two options for detecting leaks from pipelines are to have monitoring wells installed in the backfill of the pipe trench or to have a single, vertical check valve located just below the pump. If the latter is used, the check valve which may currently reside at the tank must be removed. This change allows product to run back into the tank if a leak occurs. Visual monitoring of double-walled suction piping is permitted.
- Overfill Prevention:
A device may be used which will alert the fuel transfer operator when the tank is not more than 90% full by producing an audible or visual alarm. The second option is to install a device in the fill tube or vent which will automatically shut off fuel transfer at no more than 95% capacity. Used oil tanks do not require overfill prevention devices, but if product is being “pushed” to an outside tank it is recommended to have a float device to advise the operator of a potential overfill condition. - Spill Containment:
In order to prevent small spills at the tank inlet, a liquid-tight spill containment device must be installed which is of at least 15 liter capacity. A used oil tank also requires a fixed suction tube to draw product from the tank. - Liquid and Vapor Tight Fill Couplings:
A second method of preventing spills at the tank inlet is to have connections to product delivery hoses equipped with liquid tight fittings. This type of fitting accommodates cam lock caps and replaces screw-on fill caps.
New, underground Class A construction must also include secondary containment on tanks and piping. Class B systems can be installed with single wall tanks and piping.
A precision test of underground systems is required after final cover of dirt, asphalt, or concrete is complete.
All new facilities must be designed by a professional engineer and storage tanks installed by approved contractors. New facilities must be approved by the Authority Having Jurisdiction. The authority is usually the PTMAA, but in some cases, the authority is the municipal fire department.
If underground tanks are taken out of service, they must be removed by an approved contractor within two years. If tanks are being put back into service after 12 months of inactivity, the system must be precision tested.
A leak or spill at a tank site must be reported to the local fire authority and Alberta Environment. Alberta clean-up guidelines can be printed by clicking here.