API 653 Tank Inspection Support in Ontario

Short answer: In Ontario, API 653 is written straight into provincial rules for many fuel tanks. The TSSA Liquid Fuels Handling Code requires vertical tanks built to API 650 or CAN/ULC-S601 to get an external inspection to API 653 at least every five years, and the code sets internal inspection timing for tanks without double bottoms. The owner's API 653 Authorized Inspector evaluates and signs. Atlantis performs the NDE behind that inspection and delivers the data in a digital report.

Ontario has no oil fields to speak of, but it is one of Canada's largest fuel markets and refining centres. Crude arrives by pipeline at Sarnia, where refineries, petrochemical plants and pipeline terminals form the cluster known as Chemical Valley. A second refinery sits on Lake Erie at Nanticoke. Product terminals ring the Greater Toronto and Hamilton Area, and fuel moves by ship through the Great Lakes and the St. Lawrence Seaway to terminals from Windsor to Thunder Bay. Steel mills, mines, airports, utilities and agricultural processors add their own tankage. This page sets out where those tanks are, what API 653 and the Ontario rules ask of owners, how examiner certification is handled, and exactly what Atlantis does and does not do. Atlantis performs the NDE; your API 653 Authorized Inspector remains inspector of record and signs the inspection report. To begin, send us your Ontario tank list.

Where API 653 tanks are in Ontario

Direct answer: Ontario's field-erected steel tanks are concentrated in Sarnia and Lambton County, at the Nanticoke refinery on Lake Erie, at product terminals across the Greater Toronto and Hamilton Area, at Great Lakes and Seaway marine terminals, at airport fuel farms, and at steel, chemical, mining, pulp and paper and agri-food plants across the province.

Sarnia and Chemical Valley

Sarnia is the heart of Ontario's tank population. Imperial and Suncor operate refineries there, a third refinery sits just south at Corunna, and petrochemical, plastics, synthetic rubber and specialty chemical plants line the St. Clair River. Crude arrives through Enbridge's Lines 5 and 78, and Line 9 starts at Sarnia on its way to Montreal, so terminal tankage is large and turns over constantly. Refinery tank farms hold crude, intermediates, finished gasoline and diesel, asphalt and slop oil, while the chemical plants store feedstocks, solvents and process water. Many of these tanks are decades old, have been modified more than once and sit on clay soils close to the river, which makes floor condition, settlement and the inspection history the first questions in any scope.

Nanticoke and the Lake Erie shore

Imperial's Nanticoke refinery on Lake Erie in Haldimand County is one of the larger refineries in the country by capacity and supplies much of southern Ontario. Its crude, intermediate and product tanks sit in an industrial area that also includes a steel works and a former coal-power site. Lake-shore winds, freeze-thaw cycles and long product runs between outages shape the inspection plan.

Toronto, Mississauga, Oakville and Hamilton

Most of the fuel burned in the Greater Toronto Area moves through product terminals in Toronto's port lands, Mississauga, Oakville and Hamilton, fed by pipeline, ship, rail and truck. Toronto Pearson's fuel farm stores jet fuel in large tanks. Hamilton's harbour hosts fuel, asphalt and bulk-liquid terminals beside the steel mills, which store their own fuels, acids, oils and process liquids. Tanks in this corridor are often in congested urban sites where scaffolding, crane access, traffic and neighbours constrain the work as much as the code does.

Great Lakes, Seaway and northern terminals

Marine fuel terminals and bulk-liquid facilities sit along the Detroit and St. Clair rivers, on Lake Ontario at Kingston and along the St. Lawrence, and at Thunder Bay at the head of Lake Superior. Northern Ontario adds diesel and reagent storage at mines around Sudbury and Timmins, fuel depots serving remote communities, and tanks at pulp and paper mills. Southwestern Ontario's ethanol plants, food processors and fertilizer distributors complete the picture.

What the mix means for inspection

Ontario combines very large refinery and terminal tanks with thousands of small and mid-sized shop-built tanks. The large field-erected tanks are API 650 or older API 12C construction and fall squarely under API 653. Smaller tanks may be CAN/ULC-S601 (formerly ULC-S630) vertical or horizontal tanks, which the Liquid Fuels Handling Code also brings under API 653 for vertical units. Getting the construction standard right for each tank is the first step in deciding which inspection rule applies.

What API 653 requires, in plain terms

Direct answer: API 653 governs inspection, repair, alteration and reconstruction of in-service atmospheric steel tanks built to API 650 or API 12C. It asks for routine owner checks, a formal external inspection by an Authorized Inspector at least every five years, shell UT surveys on corrosion-based intervals, and out-of-service internal inspections whose timing depends on measured floor corrosion and the tank's safeguards.

Routine in-service checks. Owner personnel look over each tank at least monthly for leaks, shell distortion, settlement signs, coating failures, roof drain and seal problems and foundation damage. On Ontario sites that includes snow and ice on floating roofs, frozen drains and frost damage to the ringwall.

External inspection. The Authorized Inspector carries out a formal external inspection at least every five years, or sooner where shell corrosion is fast, because API 653 also limits the interval to a quarter of the remaining shell corrosion life. In Ontario the Liquid Fuels Handling Code repeats the five-year ceiling for the tanks it covers.

Shell UT thickness. Where UT is used to establish shell condition, readings are due within five years of commissioning while the corrosion rate is unknown, and afterwards at the lesser of half the remaining shell corrosion life or fifteen years.

Internal inspection. The first internal inspection of a new tank is generally due within ten years, and API 653 lets owners extend it, within ceilings, by crediting safeguards such as release prevention barriers, internal linings and cathodic protection. Later intervals are calculated from measured bottom corrosion and the minimum remaining floor thickness, or set by a qualifying risk-based assessment run by the owner's own specialists. The Ontario code adds its own internal-inspection rule, explained in the next section, and the stricter of the two governs.

Edition matters. API 653 is in its fifth edition with addenda; Addendum 4 (July 2025) revised the text on measuring tank-bottom thickness. Check your procedures against the current edition from api.org. The interval decisions belong to the owner and the inspector. For the reasoning behind the numbers, see API 653 tank inspection intervals explained and the API 653 tank inspection guide.

Ontario regulations that sit on top of API 653

Direct answer: For liquid fuels, Ontario is unusual: the TSSA Liquid Fuels Handling Code, adopted under the Technical Standards and Safety Act, makes API 653 external and internal inspections mandatory for vertical tanks built to API 650 or CAN/ULC-S601. The Ontario Fire Code covers flammable and combustible liquid storage more broadly, environmental approvals and spill-prevention rules apply to major plants, and federal rules apply on federal land and at federally regulated pipeline terminals.

TSSA Liquid Fuels Handling Code

The Technical Standards and Safety Authority's Fuels Safety Program administers the Liquid Fuels Handling Code, adopted under Ontario Regulation 217/01 (Liquid Fuels). It applies to facilities that store and handle liquid fuels such as gasoline and diesel, including bulk plants, retail and private outlets and marinas. Following the code adoption document amendment published in 2018 and 2019 (FS-235-18), the code says, in summary:

• External inspection every five years. Aboveground vertical tanks built to CAN/ULC-S601 (formerly ULC-S630) or API 650 must receive an in-service external inspection at intervals not exceeding five years, in accordance with API 653.
• Internal inspection. Such tanks without double bottoms must be internally inspected at least every ten years, beginning when the tank is fifteen years old, or on the API 653 interval criteria if that is sooner.
• Records. Most records under the code are kept for seven years, but for API tank inspections only the most recent and the immediately preceding records must be retained, because these tanks often serve for decades.
• Installation and cleaning. In-field construction and installation of these tanks must be supervised by a holder of a TSSA PM.3 certificate, and draining and cleaning a tank in preparation for inspection requires a PM.3 holder or appropriate API certification under PM.3 supervision.

That last point matters when you plan an internal inspection: the cleaning contractor's qualifications are a TSSA requirement in their own right. Whether a particular tank, for example one inside a refinery fence, falls under the Liquid Fuels Handling Code or under the Fire Code alone depends on the product and the facility type. Confirm the current code edition and its application to your site with TSSA. Our TSSA compliance overview summarises how TSSA programs touch inspection companies.

Ontario Fire Code

The Ontario Fire Code (Ontario Regulation 213/07) regulates storage, handling and use of flammable and combustible liquids, including tank storage, containment, venting and fire protection, and is enforced by municipal fire departments and the Office of the Fire Marshal. Large chemical and refinery tanks that are outside the Liquid Fuels Handling Code still sit under the Fire Code and the local fire service.

Environmental approvals and spill prevention

Major refineries, chemical plants and terminals hold Environmental Compliance Approvals from the Ministry of the Environment, Conservation and Parks, which may set storage, inspection or reporting conditions. Ontario Regulation 224/07 requires spill prevention and contingency plans at plants in prescribed industrial sectors, including the petroleum sector, and those plans normally rely on tank integrity programs. Spills must be reported under the Environmental Protection Act.

Federal storage tank rules

The federal Storage Tank Systems for Petroleum Products and Allied Petroleum Products Regulations (SOR/2008-197) apply to systems on federal land and Indigenous land, to systems operated by federal bodies, and to systems serving federal works and undertakings such as airports, railways and some port facilities. In Ontario that can include fuel storage on First Nations reserve lands, at federal airports and at federal installations. For older vertical aboveground tanks without secondary containment, the regulations require either continuous leak detection or monitoring, or an inspection of the tank or tank floor every ten years, and tank inspections must follow the API 653 version in effect at the time. Confirm applicability with Environment and Climate Change Canada.

Pipelines and breakout tanks

Interprovincial and international pipelines, including the Enbridge lines into Sarnia, Line 9 and the Trans-Northern products pipeline, are regulated by the Canada Energy Regulator, and their terminal and breakout tanks sit within the operator's CER-regulated management system with CSA Z662 as the pipeline standard. Pipelines wholly within Ontario fall under TSSA's oil and gas pipeline rules and Ontario Energy Board approvals. Confirm with the relevant regulator how your tank inspections are documented; see our CSA Z662 overview for context.

Pressure equipment and radiography

Pressurised storage such as LPG bullets, butane and propane spheres and ammonia vessels is pressure equipment, regulated by TSSA's Boilers and Pressure Vessels Safety Program and CSA B51, and is inspected under API 510 rather than API 653. Industrial radiography anywhere in Canada is licensed by the Canadian Nuclear Safety Commission and exposure devices are operated by CNSC-certified operators; Atlantis uses only crews holding the required licence and certifications. See our CNSC overview.

NDE examiner qualifications in Ontario

Direct answer: Neither API 653 nor the Liquid Fuels Handling Code names a single NDE certification scheme for tank examiners, so the owner's specification decides. Some Ontario owners require CAN/CGSB-48.9712 (ISO 9712) certification; others accept ASNT SNT-TC-1A. Atlantis technicians are certified to an ASNT SNT-TC-1A written practice under ASNT Level III oversight, and we confirm acceptance during scoping.

Canada's national scheme for NDT personnel is CAN/CGSB-48.9712, which aligns with ISO 9712. Natural Resources Canada's NDT Certification Body administers certification under it. The Canadian General Standards Board, which published the standard, closed on 1 April 2026; NRCan's certification body continues and CAN/CGSB-48.9712 remains valid, according to NRCan and CWB Group notices. Because arrangements around the standard may still be settling, confirm the current certification body when you write or update a specification. Our pages on CAN/CGSB-48.9712 and the NRCan NDT Certification Body explain the scheme.

Here is the honest position. Atlantis is an ASNT-based NDE contractor. Our technicians hold certification to an SNT-TC-1A written practice, our procedures are reviewed by an ASNT NDT Level III, and every proposal states the certification basis for each method. Many Ontario tank owners, especially those with US parents, US engineering standards or corporate API programs, write SNT-TC-1A or "CGSB or SNT" into their specifications. Where a specification requires CGSB certification only, we say so plainly at the scoping stage rather than after mobilisation. Atlantis does not provide CGSB or ISO 9712 training or certification; our training is ASNT SNT-TC-1A only, through NDT training in Ontario and across Canada.

NDE methods for API 653 work in Ontario

Direct answer: Ontario tank inspections rely on floor MFL scanning proved up with UT, shell and annular-plate UT thickness surveys, automated corrosion mapping, visual examination of roofs, seals, foundations and containment, MT, PT and vacuum-box testing of repaired welds, and PAUT or radiography of new shell and nozzle welds, with settlement data supplied for the inspector.

Every reportable MFL indication is proved up with UT, and every procedure is reviewed by an ASNT NDT Level III before the crew mobilises. For the floor-scanning trade-offs see MFL versus UT for tank floors; for the full scope see aboveground storage tank inspection.

How Atlantis supports your Authorized Inspector

Direct answer: Atlantis takes the examination scope from your API 653 inspector's plan, performs the NDE, checks the data before leaving site and delivers a digital report the inspector can review, accept and sign. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors. Our role is the examinations and the data.

1. Scope from the inspector's plan: floor coverage, shell and annular-plate locations, roof, seal, foundation and dike examinations, weld examinations and settlement points, matched to the Liquid Fuels Handling Code due dates where they apply.
2. Certification check: we confirm which examiner certifications your specification requires, CGSB, SNT or either, before any crew is booked.
3. Procedure review by an ASNT NDT Level III, with temperature correction for cold-season readings.
4. Examinations by technicians certified to an SNT-TC-1A written practice: MFL with UT prove-up, shell and annular UT, corrosion mapping, visual, surface and volumetric methods.
5. Data QA on site: readings checked against calibration records and the previous inspection, with anomalies flagged to the inspector the same day.
6. Digital report in our reporting platform: floor maps, prove-up readings, shell readings by course and location, weld records, photographs, calibration data and technician certification records, on report templates matched to your inspector's file and easy to keep as the two most recent records TSSA expects.
7. Inspector evaluation and sign-off, then reuse of the same locations at the next interval, tracked in our inspection-management ERP or shown on a digital twin of the tank farm.

We can calculate corrosion rates and remaining life from our thickness data for the inspector's review; the interval decision belongs to the inspector and the owner under API 653 and the Ontario rules. Atlantis performs the NDE; your API 653 Authorized Inspector remains inspector of record and signs the inspection report. Request an NDE scope for your inspector's plan, or read about API 653 tank inspection support.

Planning around turnarounds, shipping and Ontario weather

Direct answer: Ontario internal inspections are usually planned for spring to autumn, around refinery turnarounds in Sarnia and Nanticoke, terminal product rotation and the shipping season. External UT and visual work can continue through winter with cold-weather procedures. Cleaning, NDE and repairs work best as one coordinated mobilisation.

Turnarounds. Refineries and chemical plants schedule major turnarounds years ahead, and tank work competes for scaffolding, cranes, cleaning crews and permits during those windows. Booking NDE early, with the cleaning contractor's PM.3-supervised schedule in hand, keeps the tank out of service for the shortest time.

Terminal rotation and the shipping season. GTA and Hamilton product terminals rotate tanks around supply and demand, with gasoline and diesel demand peaking in summer and heating fuels in winter. Marine terminals on the Great Lakes and the Seaway have a winter shipping closure, and some owners use that period for tank work while others avoid the cold. Your inventory plan decides.

Weather. Southern Ontario winters are milder than the Prairies, but lake-effect snow near Lakes Huron and Erie, freezing rain and temperature swings still affect UT couplants, battery life, access and technician safety. Northern Ontario sites bring true deep-cold conditions and winter-road or fly-in logistics for remote fuel depots.

Urban sites. In Toronto, Mississauga and Hamilton, traffic plans, noise limits, neighbour notification and radiography exclusion zones often push owners toward PAUT for repair welds. Confined-space entry follows Ontario's occupational health and safety rules and site permits. Book a scoping call for your next outage season.

API 653 inspection support across Ontario

Direct answer: Atlantis mobilises crews to tank sites throughout Ontario on a schedule agreed during scoping, covering Sarnia and Lambton County, Nanticoke and the Lake Erie shore, Toronto, Mississauga, Oakville and Hamilton, Windsor and the Detroit River, Kingston and the St. Lawrence corridor, Ottawa, and northern Ontario from Sudbury to Thunder Bay.

• Sarnia and Chemical Valley: refinery, petrochemical and pipeline terminal tanks. Related pages: NDT consulting in Sarnia, NDT training in Sarnia and digital twins for Sarnia assets.
• Toronto and Mississauga: product terminals, airport fuel and industrial storage. See ultrasonic testing in Toronto, radiographic testing in Toronto and NDT consulting in Toronto.
• Hamilton and Oakville: harbour terminals, asphalt storage and steel-mill tankage. See NDT consulting in Hamilton and digital twins in Hamilton.
• Nanticoke and Haldimand County: refinery tank farms on Lake Erie. See digital twins in Nanticoke.
• Windsor and the Detroit River: fuel and bulk-liquid terminals; for technician practice see practical NDT in Windsor.
• Ottawa, Kingston and the St. Lawrence: utility, institutional, chemical and marine storage; see practical NDT in Ottawa.
• Northern Ontario: mine fuel and reagent tanks around Sudbury and Timmins, remote fuel depots and the Thunder Bay terminal, planned around winter-road and seasonal access.

Pressure vessels and process piping at the same sites follow their own codes and, for pressure equipment, TSSA's program; see our companion hubs for API 510 pressure vessel inspection in Ontario and API 570 piping inspection in Ontario. For Level III procedure and written-practice support see NDT consulting in Ontario and NDT consulting across Canada; for inspection data and certification tracking see NDT ERP in Ontario.

What to send us for a quote

Direct answer: Send your tank list with construction standards, the last API 653 reports, your inspector's plan and examiner-certification requirements, the cleaning and access status, and your outage window. We return a scoped NDE quote within 24 hours.

1. Tank list and drawings: tank IDs, diameter, height, roof type, product, year built, construction standard (API 650, API 12C, CAN/ULC-S601 or ULC-S630), plate thicknesses, floor type and whether it has a double bottom, cathodic protection and leak detection.
2. Regulatory context: whether the tank falls under the Liquid Fuels Handling Code, the Fire Code alone, federal tank rules or a CER-regulated pipeline system, and the due dates each sets.
3. Previous reports: the most recent and preceding API 653 reports, floor maps, shell readings and settlement surveys.
4. The inspector's plan: examinations, coverage, acceptance references, report format and required examiner certifications, with your Authorized Inspector's name or agency.
5. Access and logistics: in service or cleaned and gas-free, cleaning contractor and PM.3 supervision, scaffolding, permits and site orientation.
6. Dates: turnaround or rotation windows and any regulatory deadline.

Get a quote within 24 hours.

Frequently asked questions: API 653 tank inspection in Ontario

Does Ontario law require API 653 tank inspections?

For many fuel tanks, yes. The TSSA Liquid Fuels Handling Code requires aboveground vertical tanks built to API 650 or CAN/ULC-S601 (formerly ULC-S630) to receive an in-service external inspection to API 653 at intervals not exceeding five years. Tanks outside that code still follow the Ontario Fire Code and their owner's integrity program, which usually adopts API 653. Confirm your site's status with TSSA.

How often must a tank be internally inspected in Ontario?

Under the Liquid Fuels Handling Code, vertical API 650 or S601 tanks without double bottoms must be internally inspected at least every ten years starting when the tank is fifteen years old, or on the API 653 interval criteria if that is sooner. Your Authorized Inspector applies whichever rule is stricter.

Who can perform an API 653 inspection in Ontario?

An API 653 Authorized Inspector, engaged by the owner directly or through an inspection agency, is responsible for the inspection and signs the report. Qualified NDE technicians collect the data. Atlantis performs that NDE with ASNT-certified technicians under Level III oversight and delivers the results to your inspector.

Is Atlantis an Authorized Inspector?

No. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors. That keeps the roles clean: your inspector evaluates independent NDE data and signs, and we stand behind the examinations and the report.

Does the cleaning contractor need TSSA certification?

The Liquid Fuels Handling Code requires that anyone draining or cleaning an API 650 or S601 tank holds a TSSA PM.3 certificate, or holds appropriate API certification and is supervised by a PM.3 holder. Atlantis performs the NDE after cleaning; we coordinate timing with your cleaning contractor.

Are your technicians CGSB certified?

No. Atlantis technicians are certified to an ASNT SNT-TC-1A written practice under ASNT Level III oversight. For tanks, the owner's specification decides which scheme is accepted, and we confirm that during scoping. CAN/CGSB-48.9712 remains valid after the Canadian General Standards Board's closure on 1 April 2026; confirm the current certification body.

How long do we have to keep API 653 inspection records?

The Liquid Fuels Handling Code keeps most records for seven years, but for API tank inspections it requires the most recent and immediately preceding records. Our digital reports keep both sets searchable and comparable, location by location.

Do federal rules apply to tanks in Ontario?

They can, on federal land, First Nations reserve land and at systems serving federal works such as airports and railways. Older vertical tanks without secondary containment then need continuous leak monitoring or a tank or floor inspection every ten years, with tank inspections following API 653.

Who licenses radiography of tank repair welds in Ontario?

The Canadian Nuclear Safety Commission, federally. Exposure devices are operated by CNSC-certified operators, and work is done only by crews holding the required licence. PAUT is often chosen instead at busy terminals and urban sites.

Do you perform RBI or fitness-for-service assessments?

No. Risk-based inspection and fitness-for-service assessments are carried out by the owner's engineers or specialist consultants. Atlantis supplies the floor, shell and weld data those assessments use.

Do you offer API 653 or CGSB certification training?

No. Atlantis offers ASNT SNT-TC-1A NDT training only, including NDT training in Ontario. For the API certification route, see our API inspector career guide.

How soon can a crew reach Sarnia, Nanticoke or Toronto?

Crews are mobilised to your site on a schedule agreed during scoping, built around cleaning, turnaround and rotation windows. Send tank details and we return a quote within 24 hours.

Plan your Ontario tank inspections

Whether it is a ten-year internal on a Sarnia crude tank, a five-year external at a Hamilton terminal or a floor repair at an airport fuel farm, start with your inspector's plan, your examiner-certification requirements and your outage window. Send us your tank list, see what an API 653 program involves, or explore practical NDT in Ontario for technician development.

More Atlantis NDT services in Ontario

• NDT training and certification in Ontario
• Level III consulting in Ontario
• API 510 pressure vessel inspection support in Ontario
• API 570 piping inspection support in Ontario
• NDT ERP software in Ontario
• Practical NDT simulator in Ontario

Part of the wider aboveground storage tank inspection service at Atlantis NDT.