API 653 Tank Inspection Support in Washington

Short answer: In Washington, an API 653 tank inspection is evaluated and signed by the owner's API 653 Authorized Inspector, and at the state's large oil-handling facilities the Department of Ecology's facility rules also tell owners to inspect storage tanks to API 653 and to take seismic risk into account. Atlantis performs the NDE behind those inspections, from floor MFL scanning with UT prove-up to shell UT and repair-weld examination, at refineries, marine terminals and inland fuel depots, and delivers the data to your inspector in a structured digital report.

Washington's tank population is unusual. Five refineries sit on the shores of northern and southern Puget Sound, crude arrives by tanker, pipeline and rail, refined products move south through a single major products pipeline and by barge up the Columbia and Snake rivers, and almost all of it sits in a region where engineers plan for a Cascadia subduction-zone earthquake. That combination has produced one of the few state rules that names API 653 directly and then layers seismic protection on top. This page explains where Washington's tanks are, what API 653 asks for, how Ecology, the Utilities and Transportation Commission and federal rules fit together, and exactly what Atlantis does on site. Atlantis performs the NDE; your API 653 Authorized Inspector remains inspector of record and signs the inspection report. To start, send us your Washington tank list.

Where API 653 tanks are in Washington

Direct answer: Washington's field-erected tanks cluster at the Puget Sound refineries in Whatcom, Skagit and Pierce counties, at marine and products terminals in Seattle, Tacoma, Everett and Vancouver, along the Olympic products pipeline corridor, at inland river and rail-served depots in the Tri-Cities and Spokane, and at airports, utilities, pulp and paper mills and food-processing plants.

Northern Puget Sound refining: Whatcom and Skagit counties

Two refineries operate in Whatcom County, BP's Cherry Point refinery near Blaine and the Phillips 66 Ferndale refinery, and two more sit side by side on March Point at Anacortes in Skagit County, operated by Marathon and by HF Sinclair. Together these four sites hold crude tanks fed by tankers and by the Trans Mountain system's Puget Sound line from Canada, plus intermediate, blendstock and finished-product tanks. Many tanks date from the refineries' construction in the 1950s and 1970s, so floors may already have been replaced once and shell courses may carry patch plates, inserts or nozzle additions from decades of service changes. Marine air, frequent rain and coastal fog drive coating breakdown and external corrosion at the chime and on wind girders, while floating-roof tanks deal with heavy rainfall loads on the deck and drains.

Tacoma, Seattle and Everett terminals

Par Pacific operates a refinery on the Tacoma tideflats, alongside bulk-liquid and products terminals around Commencement Bay. Harbor Island and the Duwamish waterway in Seattle hold petroleum terminals that supply the city, the airport and marine fuelling, and Everett has its own terminal capacity. Many of these sites stand on reclaimed tideland or river delta fill. That matters for API 653 work: soft and variable foundations make settlement surveys and edge-settlement evaluation more important than at inland sites, and high groundwater and tidal influence can accelerate soil-side floor corrosion.

The Olympic Pipeline corridor

The Olympic Pipeline carries gasoline, diesel and jet fuel from the northern refineries south through the I-5 corridor to Seattle, Tacoma, Sea-Tac and on to Portland, Oregon. Its delivery and pump-station facilities include breakout tanks, which brings the federal hazardous-liquid pipeline rules and their API 653 requirement into play. The 1999 Whatcom Creek rupture in Bellingham on this system led directly to Washington's 2000 Pipeline Safety Act and to the state's unusually active pipeline-safety programme.

Vancouver and the Columbia-Snake river system

The Port of Vancouver on the Columbia River handles liquid bulk, and fuel moves by barge up the Columbia and Snake rivers to terminals around the Tri-Cities (Pasco, Kennewick and Richland) and farther inland. River-terrace tanks face flood risk and groundwater variation, and inland depots see hot, dry summers and cold winters, a very different exposure from coastal Puget Sound.

Spokane and eastern Washington

Spokane is supplied by pipeline from the east and holds products terminals serving eastern Washington and northern Idaho, plus Fairchild Air Force Base and the airport. Across the Columbia Basin, agricultural chemical and fertilizer tanks, ethanol and biodiesel facilities, and food-processing plants add carbon-steel tanks that owners often inspect to API 653 by choice.

Industrial and utility tanks

Pulp and paper mills in southwest Washington and on the Olympic Peninsula use large tanks for fuel oil, black liquor and chemicals; utilities hold backup fuel; and military installations around Puget Sound maintain their own fuel farms. Not every one of these is an API 650 oil tank, so the owner and inspector first decide which code applies before an NDE scope is written.

What API 653 requires, in plain terms

Direct answer: API 653 covers inspection, repair, alteration and reconstruction of in-service atmospheric steel tanks built to API 650 or its predecessor API 12C. It sets owner checks at least monthly, a formal external inspection by the Authorized Inspector, shell UT thickness surveys and an out-of-service internal inspection, each with intervals tied to measured corrosion inside fixed ceilings. The current edition is the Fifth, with addenda through Addendum 4 (July 2025).

Routine in-service checks. The owner's own personnel look over each tank at least monthly for leaks, shell distortion, signs of settlement, coating failure, roof and seal damage, blocked drains and foundation deterioration. On Puget Sound floating-roof tanks, ponding water on the deck after long rain events and plugged roof drains are classic findings.

Formal external inspection. The Authorized Inspector carries out an external inspection at least every five years, or sooner when shell corrosion is fast, because the code ties the interval to a quarter of the remaining shell corrosion life. The tank stays in service.

Ultrasonic thickness of the shell. Where UT readings are used, the code requires them within five years while the corrosion rate is unknown, then at the lesser of half the remaining shell corrosion life or fifteen years.

Internal inspection. The out-of-service inspection establishes floor condition. For a new tank, the first internal is due within ten years; credited safeguards such as linings, cathodic protection, leak detection and release prevention barriers can extend it to a ceiling of twenty years without a release prevention barrier or thirty years with one. Later intervals are set from measured bottom corrosion so the floor stays above the code's minimum at the next inspection, within the same ceilings, or by a qualifying risk-based assessment carried out by the owner's specialists.

Settlement, brittle fracture and repairs. API 653 includes an annex for evaluating settlement, a procedure for judging brittle-fracture risk when a tank's service changes or after repairs, and examination and testing requirements for repaired and altered welds, with API 650 as the construction reference. Addendum 4 revised the text on measuring tank-bottom plate thickness, so inspection plans and procedures written against earlier text should be checked against the current edition and addendum from api.org. All of these are decisions for the owner and the inspector. For a deeper explanation, see API 653 tank inspection intervals explained and our API 653 tank inspection guide.

Washington regulations that sit on top of API 653

Direct answer: At the state's large oil-handling facilities, Ecology's facility oil handling standards (chapter 173-180 WAC) require storage tanks to be inspected and maintained to API 653 and, since 2023, to carry seismic protection measures. The UTC regulates pipeline safety, PHMSA's 49 CFR 195.432 applies API 653 to breakout tanks, and EPA SPCC and OSHA PSM complete the picture. Confirm current requirements with Ecology.

Department of Ecology: chapter 173-180 WAC

Washington's Department of Ecology regulates the oil-handling facilities that the state classifies as Class 1 facilities, broadly the larger marine and pipeline oil-transfer sites such as refineries and terminals, under chapter 173-180 WAC, with spill contingency planning under chapter 173-182 WAC. The storage-tank section of the facility rules, WAC 173-180-330, requires tanks to be maintained, repaired and inspected in accordance with API 653, citing a specific 2014 edition with Addenda 1 and 2, unless Ecology approves an equivalent inspection strategy proposed by the operator. Note that the edition named in the rule is older than the current Fifth Edition with Addendum 4, so facilities usually need procedures that satisfy both the rule's referenced edition and current practice; Ecology is the authority on how it applies that reference.

In June 2023 Ecology amended the rule to add seismic protection. Tanks built before the amendment must be fitted with protective measures, such as flexible connections or adequate piping flexibility between tank and piping, driven foundation piles, tank anchorage or another measure Ecology approves, within ten years of the rule's effective date or by the tank's next scheduled internal API 653 inspection, whichever is later. New tanks must meet the seismic design provisions of API 650's Annex E, including piping flexibility, along with the referenced ASCE 7 and building-code seismic criteria. Ecology also expects the results of API 653 inspections to feed the facility's spill risk analysis. In practical terms, the internal inspection has become the natural point for evaluating anchorage, nozzle loads and piping flexibility, and the NDE data gathered during that outage support both the API 653 evaluation and the seismic work the owner's engineers carry out.

UTC pipeline safety and PHMSA breakout tanks

The Washington Utilities and Transportation Commission's pipeline safety programme inspects intrastate natural gas and hazardous-liquid pipelines and, as an interstate agent for PHMSA, also inspects interstate lines in the state, referring enforcement on interstate systems to PHMSA. Under 49 CFR 195.432, steel breakout tanks on regulated hazardous-liquid pipelines that operate at atmospheric or low pressure must be inspected in accordance with API 653, without the code's alternative risk-based internal interval, while pressurised breakout tanks follow API 510. The federal rule also incorporates an older edition of API 653, so pipeline operators reconcile three references in Washington: the federal edition, the state facility rule's edition and the current code.

EPA SPCC and OSHA PSM

Facilities subject to EPA's Spill Prevention, Control and Countermeasure rule (40 CFR Part 112) must test or inspect each aboveground oil container for integrity on a regular schedule and after material repairs, following industry standards: API 653 for field-erected tanks and STI SP001 for shop-built tanks. Washington is a State Plan state for occupational safety, administered by the Department of Labor and Industries, so refinery process safety management is enforced by L&I under the state's own PSM rule, which follows the mechanical-integrity principles of the federal standard at 29 CFR 1910.119(j). L&I adopted a refinery-specific Part B of chapter 296-67 WAC at the end of 2023, effective December 2024 with phased implementation dates, so refinery mechanical-integrity programmes in Washington answer to that rule as well; confirm current requirements with L&I.

Radiography in Washington

Washington is an NRC Agreement State, and radioactive-materials licensing, including industrial radiography, is administered by the Department of Health's Office of Radiation Protection. Repair-weld radiography on Washington tanks is performed only by crews licensed for that work in Washington; confirm current licensing requirements with the Department of Health when RT is planned.

NDE methods for API 653 work in Washington

Direct answer: Washington tank work centres on floor MFL scanning with UT prove-up, shell and annular-plate UT, corrosion mapping of shell courses and nozzles, visual examination of floating roofs, seals and anchorage, MT, PT and vacuum-box testing after repairs, PAUT or RT on new welds, and settlement data on tideland and river-terrace foundations.

Procedures are reviewed by an ASNT NDT Level III and technicians are certified to an SNT-TC-1A written practice. MFL screens the floor quickly, and every reportable indication is proved up with UT so the inspector evaluates measured remaining thickness, not a screening signal. For method trade-offs see MFL versus UT for tank floors, and for scope detail see aboveground storage tank inspection.

How Atlantis supports your Authorized Inspector

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

1. Scope from the inspector's plan: floor coverage, shell and annular-plate locations, roof and seal examinations, anchorage and nozzle examinations, weld examinations and settlement points.
2. Procedure review by an ASNT NDT Level III for the tank's construction, coating, lining and service, including heated, insulated and asphalt tanks.
3. Examinations by technicians certified to an SNT-TC-1A written practice: MFL and UT prove-up, shell and annular UT, corrosion mapping, visual, surface and volumetric methods.
4. Data QA on site: readings checked against calibration records and the previous inspection before the crew demobilises, while scaffolds and access still exist.
5. Digital report in 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 matched to the inspector's file and to what your Ecology and SPCC records need.
6. Inspector evaluation and sign-off: the inspector evaluates the data, decides on repairs and sets the next inspection dates.
7. Reuse at the next interval: the same locations next time, tracked in our inspection-management ERP or presented in 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 Washington and federal rules that apply. Atlantis performs the NDE; your API 653 Authorized Inspector remains inspector of record and signs the inspection report. For a facility juggling the state's referenced edition, PHMSA's referenced edition and the current code, independent, well-documented NDE data is what lets the inspector satisfy all three without re-measuring. Request an NDE scope for your inspector's plan, or see API 653 tank inspection support.

Planning around rain, seismic retrofits and outages

Direct answer: Western Washington's long wet season and eastern Washington's winter cold both shape tank NDE scheduling, and since 2023 internal inspections at Class 1 facilities often double as the window for seismic protection work. Plan cleaning, NDE, repairs and any retrofit as one outage so the tank is opened only once.

Combine the internal inspection with seismic work. Because Ecology's rule lets existing tanks meet the seismic requirement by their next internal API 653 inspection where that is later than the ten-year date, many owners will plan anchorage, flexible connections or piping changes into the same outage. That makes the NDE scope larger than a routine internal: annular-plate thickness where anchor chairs will be welded, nozzle-region examination where piping is modified, and MT or PT of new attachment welds after the work. Writing those into the inspector's plan up front saves a second mobilisation.

Rain and coatings west of the Cascades. From autumn to spring, persistent rain and high humidity make surface preparation, couplant behaviour and external coating work harder, and wet steel complicates MT and PT. External UT and visual examinations continue year-round, but coating repairs and some surface methods are easier in the drier summer months.

Cold east of the Cascades. Spokane and the Tri-Cities see sub-freezing winters, and ice makes stairs, roofs and wind girders hazardous. Internal inspections there tend to be scheduled from spring to autumn.

Cleaning and marine logistics. Crude and heavy-oil tanks at the refineries can take longer to clean than to inspect, and terminal tanks tied to marine schedules have to be released around vessel arrivals. Book the NDE crew for the day the tank is released for entry, not before. Book a scoping call with your outage plan.

API 653 inspection support across Washington

Direct answer: Atlantis mobilises crews to tank sites throughout Washington on a schedule agreed during scoping: Whatcom and Skagit counties, Everett, Seattle, Tacoma, Vancouver, the Tri-Cities and Spokane. The Seattle pages below cover tank, corrosion, pipeline, piping and vessel inspection in the region in more detail.

• Seattle and central Puget Sound: tank inspection in Seattle and corrosion inspection in Seattle.
• Pipelines, terminal piping and pressure equipment: pipeline inspection in Seattle, piping inspection in Seattle and pressure vessel inspection in Seattle.
• Cherry Point, Ferndale, Anacortes, Tacoma, Vancouver, the Tri-Cities and Spokane: served by mobilised crews; include the site address and any site-specific orientation requirements with your tank list.

The piping, manifolds and pressure vessels at the same sites follow their own codes; see our companion hubs for API 570 piping inspection in Washington and API 510 pressure vessel inspection in Washington, and the statewide NDT inspection services in Washington page. Pipeline operators can also see pipeline inspection services.

What to send us for a quote

Direct answer: Send your tank list and drawings, the last API 653 reports, your inspector's plan, the cleaning and access status, any seismic retrofit scope and your dates. We return a scoped NDE quote within 24 hours.

1. Tank list and drawings: tank IDs, diameter, height, roof type, product, year built, plate thicknesses, bottom and lining history, cathodic protection, anchorage details and whether the tank is a pipeline breakout tank or sits at a Class 1 facility.
2. Previous reports: external and internal API 653 reports, floor maps, shell readings and settlement surveys, so we repeat locations and corrosion rates stay valid.
3. The inspector's plan: examinations, coverage, acceptance references and report format, with the name of your Authorized Inspector or inspection agency.
4. Seismic scope: any anchorage, nozzle or piping-flexibility work your engineers plan for the outage, so the NDE before and after that work is included.
5. Access and dates: cleaning contractor, gas-free and confined-space arrangements, marine or pipeline schedule constraints, internal due dates and site orientation needs.

Get a quote within 24 hours.

Frequently asked questions: API 653 tank inspection in Washington

Who can perform an API 653 inspection in Washington?

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

Does Washington law require API 653 inspections?

For Class 1 oil-handling facilities, yes: WAC 173-180-330 requires storage tanks to be maintained, repaired and inspected in accordance with API 653 unless Ecology approves an equivalent strategy. Breakout tanks fall under PHMSA's API 653 requirement, and SPCC facilities use API 653 as the industry standard. Confirm applicability with Ecology.

Which edition of API 653 does Washington reference?

The state facility rule cites a 2014 edition of API 653 with Addenda 1 and 2, while the current code is the Fifth Edition with addenda through Addendum 4 (July 2025), and PHMSA's rule references an older edition again. Owners and inspectors decide how to reconcile them; ask Ecology if the rule's reference is unclear for your tank.

What does the 2023 seismic rule mean for my tank inspection?

Existing tanks at Class 1 facilities need seismic protection measures within ten years of the rule's effective date or by their next scheduled internal API 653 inspection, whichever is later. Many owners will plan that work into the internal inspection outage, so the NDE scope often grows to cover anchorage, nozzle and new attachment welds.

How often does a Puget Sound refinery tank need an internal inspection?

Under API 653, a new tank's first internal is due within ten years, extendable through credited safeguards to twenty years, or thirty with a release prevention barrier. Later intervals follow measured floor corrosion within the same ceilings. Breakout tanks cannot use the risk-based alternative. The inspector and owner set the actual date.

Are Olympic Pipeline and other breakout tanks treated differently?

Yes. Breakout tanks on regulated hazardous-liquid pipelines must be inspected per API 653 under 49 CFR 195.432, without the risk-based internal interval option. In Washington the UTC inspects pipelines, including interstate systems as PHMSA's agent, so expect both agencies' records to be reviewed.

Is Atlantis an 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 keeps the data independent of whoever holds the inspector role.

Can you inspect while the tank stays in service?

Yes for shell UT, corrosion mapping, external visual examination including floating-roof and seal checks, anchorage condition and settlement readings. Floor scanning and internal weld examination need 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, and procedures are reviewed by an ASNT NDT Level III. Radiography is performed only by crews licensed for industrial radiography in Washington.

Do you perform RBI, fitness-for-service or seismic engineering?

No. Risk-based inspection, fitness-for-service and seismic design are performed by the owner's engineers or specialist consultants. Atlantis supplies the floor, shell, annular-plate 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 Washington. For the API certification route, see our API inspector career guide.

How soon can a crew reach Anacortes, Tacoma or Spokane?

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

Plan your Washington tank inspections

Whether it is a floor scan during a seismic-retrofit outage at Anacortes, a shell survey at a Tacoma terminal or a settlement check on a river-terrace tank in the Tri-Cities, start with your inspector's plan and your tank list. Send us your tank list, or see NDT consulting in Washington for Level III procedure support.

More Atlantis NDT services in Washington

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

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