API 653 Tank Inspection Support in Illinois

Short answer: In Illinois, an API 653 tank inspection is signed by the owner's API 653 Authorized Inspector, not by the NDE crew. The inspector relies on floor scans, shell thickness data, weld examinations and settlement readings gathered by qualified technicians. Atlantis performs that NDE at Illinois refineries, crude hubs and product terminals, from the Chicago area to Patoka and the Wood River region, and hands the data to your inspector in a digital report.

Illinois holds one of the densest concentrations of field-erected storage tanks in the interior of the country. Four refineries operate in the state, the crude hub at Patoka is a meeting point for several major crude pipelines, and the Chicago area, the Illinois Waterway and the Mississippi River corridor around Wood River and Hartford support a long chain of products, chemical and barge terminals. Layered on top are agricultural chemical storage, ethanol plants and oil-field tankage in the Illinois Basin. This page explains where those tanks are, what API 653 requires, which Illinois and federal rules apply, and 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. If you already have a list of tanks coming due, send us your Illinois tank list.

Where API 653 tanks are in Illinois

Direct answer: Illinois field-erected tanks cluster in five places: the Chicago, Joliet and Lemont refining and terminal belt; the Patoka crude hub in Marion County; the Wood River, Roxana and Hartford corridor across the Mississippi from St. Louis; the Robinson refinery in Crawford County; and barge, agricultural and ethanol tankage along the Illinois River and across central Illinois.

Chicago, Joliet and the I-55 corridor

The ExxonMobil refinery near Joliet in Will County and the Citgo refinery at Lemont anchor the northern cluster. Around them sit products terminals fed by pipeline and barge, chemical plants along the Des Plaines and Illinois rivers near Channahon and Morris, and terminals around Lake Calumet and the Calumet River on Chicago's south side. Tank types range from large crude and intermediate tanks inside refinery fences to internal floating-roof gasoline tanks, distillate tanks, asphalt tanks with heated contents and chemical storage. Many of these tanks are several decades old and have been re-bottomed, re-roofed or changed in service, which makes a clean, continuous inspection history especially valuable.

Patoka and the crude hub in southern Illinois

Patoka, in Marion County, is a major crude oil hub where long-haul crude pipelines meet, including the southern end of the Dakota Access Pipeline, and where crude moves on toward Gulf Coast and Midwest refineries. The tank farms there are dominated by large crude tanks, many of them external floating-roof designs, operated by pipeline companies. A large share of these are breakout tanks on regulated hazardous-liquid pipelines, which brings federal pipeline inspection rules directly into play (see the regulations section below).

Wood River, Roxana and Hartford

The Metro East area across the river from St. Louis holds the large refinery at Roxana, operated by Phillips 66 for the WRB joint venture, together with products terminals, pipeline stations and river docks around Wood River and Hartford. This is low ground protected by levees along the Mississippi, so groundwater, flood stages and soft soils influence tank foundations and floor corrosion.

Robinson and the Illinois Basin

Marathon Petroleum's refinery at Robinson in Crawford County sits in the heart of the Illinois Basin oil region of southeastern Illinois. Oil-field production and gathering tanks there are usually smaller and fall under the state's oil and gas regulator rather than storage-tank rules, but the refinery, crude receipt stations and gathering hubs carry field-erected tanks that follow API 653.

Illinois River, ag and ethanol storage

Central Illinois is grain country. Ethanol plants, oilseed processors, fertilizer terminals and barge loading docks along the Illinois River at Peoria, Havana, Pekin and elsewhere hold denatured ethanol, gasoline denaturant, vegetable oils, liquid fertilizer and molasses. Not all of these tanks are petroleum tanks, but owners often use API 653 as the inspection framework for welded steel tanks of any service because it is the recognised practice for atmospheric storage.

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 its predecessor API 12C. It sets owner monthly checks, a formal external inspection by the Authorized Inspector, shell thickness surveys and internal inspections tied to measured corrosion, with ceilings. The current Fifth Edition carries addenda through Addendum 4 (July 2025).

Monthly routine checks. Operations staff walk the tank at least monthly, looking for leaks, shell distortion, signs of settlement, damaged insulation or coatings, roof drain and seal problems and foundation cracking. In a Chicago winter that list grows to include ice on roofs and stairways, frozen roof drains on floating roofs and frost heave around the tank pad.

Formal external inspection. The Authorized Inspector carries out an external inspection at least every five years. Where the shell is corroding quickly, the code shortens that to a quarter of the remaining shell corrosion life (expressed in the code as RCA/4N, where RCA is the remaining corrosion allowance and N is the corrosion rate). The tank can stay in service.

Shell ultrasonic thickness. Where the owner uses UT thickness measurements, they are taken at least every five years while the corrosion rate is not yet known. Once a rate is established, the interval becomes the smaller of half the remaining shell corrosion life (RCA/2N) or fifteen years.

Internal (out-of-service) inspection. The internal inspection is where floor scanning, weld examination and critical-zone measurements happen. For a new tank, the initial internal interval is ten years; safeguards such as a lining, cathodic protection, leak detection or a release prevention barrier can extend it, up to a ceiling of twenty years without a release prevention barrier and thirty years with one. After the first internal, the next interval is set from measured floor corrosion and the minimum bottom thickness the code accepts at the next inspection, or from a qualifying risk-based assessment carried out by the owner's specialists. Addendum 4 revised the text on how tank-bottom plate thickness is measured, so check that your procedures and your inspector's plan reflect the current edition and addendum, available from api.org.

Settlement and repairs. Settlement surveys are evaluated against the code's settlement annex, and repairs, alterations and reconstruction follow the code's examination and testing requirements, drawing on API 650. These decisions belong to the owner and the Authorized Inspector. For a deeper explanation of how intervals are worked out, read API 653 tank inspection intervals explained and the broader API 653 tank inspection guide.

Illinois regulations that sit on top of API 653

Direct answer: Illinois has no state law that prescribes API 653 inspection intervals for every aboveground tank. Instead, the Office of the State Fire Marshal regulates flammable and combustible liquid tanks under 41 Ill. Adm. Code Parts 160 and 180, PHMSA enforces API 653 on pipeline breakout tanks, EPA's SPCC rule requires integrity testing to industry standards, and OSHA PSM applies inside covered processes.

Office of the State Fire Marshal (OSFM)

OSFM's aboveground tank rules cover tanks holding flammable or combustible liquids: Part 160 for bulk (non-dispensing) storage tanks and Part 180 for fuel-dispensing tanks. OSFM states that it has no jurisdiction over tanks whose contents are neither flammable nor combustible, and that bulk storage tanks larger than 110 gallons go through an application submittal and field inspection process. These are siting, construction, installation and fire-safety rules rather than a periodic integrity-inspection regime, so for in-service condition the industry standard (API 653 for field-erected tanks, STI SP001 for shop-built ones) is what the owner relies on. Exactly which tanks at a refinery, terminal or industrial site fall within OSFM's rules depends on the facility; confirm current applicability with OSFM.

PHMSA and Illinois pipelines

Under 49 CFR 195.432, atmospheric and low-pressure steel breakout tanks on regulated hazardous-liquid pipelines must be inspected in accordance with API 653, except that the code's alternative, risk-based internal inspection interval may not be used; breakout tanks built as pressure vessels are inspected under API 510. That matters a great deal at Patoka and at pipeline stations around Chicago and Wood River. The regulation incorporates a specific, older edition of API 653 by reference, so the operator's procedures must reconcile the incorporated edition with the current one. In Illinois, the Illinois Commerce Commission's pipeline safety programme covers intrastate natural gas systems; PHMSA itself inspects both intrastate and interstate hazardous-liquid pipelines in the state. The ICC also handles certificate applications for hazardous-liquid pipelines under the Public Utilities Act.

EPA SPCC and OSHA PSM

Facilities storing oil above the SPCC thresholds must test or inspect each aboveground container for integrity on a regular schedule and after material repairs, with the frequency, type of testing and inspector qualifications set by industry standards. API 653 is the standard for field-erected tanks and STI SP001 for shop-built tanks; the certifying engineer writes the chosen approach into the SPCC plan. Where a tank is part of an OSHA PSM-covered process, as many refinery and chemical tanks are, 29 CFR 1910.119(j) requires written inspection and testing procedures that follow recognised and generally accepted good engineering practice, and API 653 is the practice most owners cite.

Other Illinois agencies you may meet

Oil-field production tanks in the Illinois Basin come under the Illinois Department of Natural Resources' oil and gas regulation, and agricultural chemical storage can fall under Illinois Department of Agriculture containment rules; confirm applicability for each site. For radiography of repair welds, Illinois is an NRC Agreement State, and industrial radiography licensing is handled by the Illinois Emergency Management Agency; confirm current licensing authority with the state before planning RT.

NDE methods for API 653 work in Illinois

Direct answer: The NDE behind an Illinois API 653 inspection is mainly floor MFL scanning with UT prove-up, shell and critical-zone UT, visual examination of shell, roof and appurtenances, surface methods and vacuum-box testing after repairs, volumetric examination of new welds, and settlement data. Patoka's crude tanks and Chicago-area product tanks call for different emphasis.

Procedures are reviewed by an ASNT NDT Level III and technicians are certified to an SNT-TC-1A written practice. Radiography is performed only by crews licensed for industrial radiography in Illinois. MFL is a screening method: indications above the reporting threshold are proved up with UT before the inspector uses them, which is why the table pairs the two. For the trade-offs between methods on floors, see tank floor scanning: MFL versus UT, and for scope detail see aboveground storage tank inspection.

How Atlantis supports your Authorized Inspector

Direct answer: Atlantis takes the examinations your API 653 inspector's plan calls for, performs them with certified technicians under Level III oversight, checks the data on site, and delivers a structured digital report the inspector can evaluate and sign against. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors.

1. Scope from the plan. We start from the inspector's plan: floor coverage, shell locations, critical-zone readings, nozzle and weld examinations, and the data format the inspector wants.
2. Procedures. An ASNT NDT Level III reviews procedures against the tank's construction, coatings and service, including heated and insulated tanks.
3. Examinations. Floor MFL and UT prove-up, shell and critical-zone UT, visual examination, surface methods and weld examinations, by technicians certified to an SNT-TC-1A written practice.
4. Data QA. Readings are checked against calibration records and the previous inspection before the crew leaves, so that unexpected results can be re-measured while access still exists.
5. Digital report. Results are delivered through our reporting platform: floor maps, prove-up readings, shell readings by course and location, weld records, photographs, calibration data and technician certifications, using report templates aligned with the inspector's file.
6. Evaluation and sign-off. The inspector evaluates the data, decides on repairs and sets the next inspection dates.
7. Reuse. The same locations are measured next time, and results can be tracked in our inspection-management ERP or visualised in a digital twin.

We can calculate corrosion rates and remaining life from our thickness data for the inspector's review, but the interval decision is the inspector's and the owner's under API 653 and whatever regulation applies. Atlantis performs the NDE; your API 653 Authorized Inspector remains inspector of record and signs the inspection report. Many Illinois tank owners use firms that sell the Authorized Inspector service as a package. We sell the NDE behind it, which lets you keep your own inspector, or your contracted inspection agency, and still get independent, well-documented data. Request an NDE scope for your inspector's plan, or read more on API 653 tank inspection support.

Planning around Illinois winters, river levels and outages

Direct answer: Shell UT, external visual work and settlement readings can be done in service for most of the year in Illinois. Internal inspections, floor scanning and repair welding are usually planned from spring to autumn, aligned with refinery turnarounds, pipeline throughput and river conditions on the Mississippi and Illinois rivers.

Cold weather. Northern Illinois winters slow everything that happens on a tank roof or inside an open, cold tank. Couplant behaviour, battery life, coating cure times and safe access on icy stairways all suffer. MFL scanning in a cold, damp tank can be done, but it is slower, and the repair and re-coating work that follows is easier in milder months. Terminal owners therefore often schedule out-of-service work between April and October.

River levels. The Wood River and Hartford area sits behind Mississippi River levees, and barge terminals along the Illinois River see high-water seasons. High groundwater can affect cathodic protection performance and floor corrosion, and floods can disturb foundations. A settlement survey after a significant high-water event, compared with the baseline, gives the inspector evidence on whether a tank moved.

Pipeline throughput at Patoka. Taking a large crude tank out of service at a pipeline hub means coordinating with shippers and other tanks in the system. Cleaning a crude tank can take longer than the inspection itself, so NDE should be booked well ahead and the crew scheduled for the day the tank is released for entry.

Refinery turnarounds. Refinery tanks that are not part of a process unit can be taken out of service independently, but tank work often competes with turnaround resources for cleaning crews, scaffolding and permits. Booking the NDE crew early and confirming coverage with your inspector avoids gaps. Book a scoping call with your outage dates.

API 653 inspection support across Illinois

Direct answer: Atlantis mobilises NDE crews to tank sites anywhere in Illinois, with the schedule agreed during scoping: Chicago, Joliet and Lemont, Patoka and Marion County, Wood River and the Metro East, Robinson, and the Illinois River terminals. The Chicago pages below cover tank, corrosion, piping, vessel, weld and third-party inspection in detail.

• Chicago and northern Illinois: tank inspection in Chicago, corrosion inspection in Chicago, weld inspection in Chicago and third-party inspection in Chicago.
• Terminal and refinery piping and pressure equipment: piping inspection in Chicago and pressure vessel inspection in Chicago.
• Downstate Illinois: Patoka, Wood River, Roxana, Hartford, Robinson, Peoria and the Illinois River terminals are served by mobilised crews; send the site address with your tank list.

Tank inspections rarely stop at the tank. The fill and suction lines, pump manifolds and any pressure vessels on site follow their own codes; see our companion hubs for API 570 piping inspection in Illinois and API 510 pressure vessel inspection in Illinois, and the statewide NDT inspection services in Illinois page. Pipeline operators can also see pipeline inspection services.

What to send us for a quote

Direct answer: Send the tank list with sizes and service, the last API 653 reports, your inspector's plan, the access and cleaning status, and your target dates. We return a scoped NDE quote within 24 hours.

1. Tank list and drawings: tank numbers, diameter, height, roof type, product, construction date, plate thicknesses, bottom type, lining, cathodic protection and whether the tank is a pipeline breakout tank.
2. Last inspection reports: previous external and internal reports, floor maps, shell readings and settlement surveys, so we measure the same locations and the corrosion rate is meaningful.
3. The inspector's plan: required examinations, coverage, acceptance references and the report format, plus the name of your Authorized Inspector or inspection agency.
4. Access and cleaning: in service or out of service, the cleaning contractor, gas-free and confined-space arrangements, scaffold, rope access or roof access.
5. Dates: SPCC and PHMSA due dates, outage windows, turnaround dates and site safety orientation requirements.

Get a quote within 24 hours.

Frequently asked questions: API 653 tank inspection in Illinois

Who can perform an API 653 tank inspection in Illinois?

The inspection itself is the responsibility of an API 653 Authorized Inspector working for the owner or an inspection agency; that inspector evaluates the data and signs. The NDE is performed by qualified technicians. Atlantis performs that NDE with ASNT-certified technicians under Level III oversight and delivers the results to your inspector.

Does Illinois law require API 653 inspections?

Not as a blanket state rule. OSFM's Parts 160 and 180 govern flammable and combustible liquid tanks mainly for siting, construction and fire safety. API 653 becomes mandatory through federal rules: PHMSA for breakout tanks, and in practice EPA SPCC and OSHA PSM, which point to industry standards. Confirm your facility's obligations with OSFM and your SPCC plan.

Are Patoka crude tanks inspected differently?

Many Patoka tanks are pipeline breakout tanks, so 49 CFR 195.432 requires API 653 inspection and bars the code's alternative risk-based internal interval. PHMSA inspects hazardous-liquid pipelines in Illinois directly. Operators should check how the incorporated API 653 edition relates to the current edition.

How often does a storage tank need an API 653 inspection?

Monthly routine checks by the owner; a formal external inspection by the Authorized Inspector at least every five years or sooner if the shell corrosion rate demands it; shell UT on a five-year to fifteen-year cycle based on corrosion rate; and internal inspections starting at ten years for a new tank, then set from measured floor corrosion within the code's ceilings.

Does OSFM inspect my tanks?

OSFM reviews applications and performs field inspections for regulated flammable and combustible liquid tanks, mainly at installation and for fire-code compliance. That is separate from the API 653 integrity inspection your Authorized Inspector performs. Contact OSFM for current requirements.

Is Atlantis an API 653 Authorized Inspector?

No. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors. We perform and document the NDE; your inspector evaluates it and signs. That separation gives you independent data and lets you keep the inspector you already trust.

What NDE methods are used on Illinois storage tanks?

Floor MFL with UT prove-up, shell and critical-zone UT, corrosion mapping, visual examination, MT, PT and vacuum-box testing after repairs, PAUT or RT of new welds, and settlement surveys. The mix depends on tank type, service and the inspector's plan.

Can you inspect while the tank stays in service?

Yes for external visual examination, shell UT, corrosion mapping of the shell and settlement readings. Floor scanning, internal weld examination and critical-zone measurements from inside require the tank emptied, cleaned and gas-free.

What certifications do your technicians hold?

Technicians are certified to an ASNT SNT-TC-1A written practice for each method they perform, and procedures are reviewed by an ASNT NDT Level III. Radiography is carried out only by crews licensed for industrial radiography in Illinois.

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

No. Risk-based inspection programmes and fitness-for-service assessments are performed by the owner's engineers or specialist consultants. Atlantis supplies the thickness, floor and weld data those assessments rely on.

Do you offer API 653 certification training?

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

How soon can a crew reach Chicago, Patoka or Wood River?

Crews are mobilised to your site on a schedule agreed during scoping, built around your outage window and due dates. Send your tank details for a quote within 24 hours.

Plan your Illinois tank inspections

Whether it is a five-year external survey at a Lemont terminal, a floor scan on a Patoka crude tank or a repair inspection on a Wood River products tank, start with your inspector's plan and your tank list. Send us your tank list, or see NDT consulting in Illinois for Level III procedure support.

More Atlantis NDT services in Illinois

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

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