API 653 Tank Inspection Support in Mississippi

Short answer: In Mississippi, an API 653 tank inspection is evaluated and signed by the owner's API 653 Authorized Inspector. The Mississippi Department of Environmental Quality does not run its own aboveground tank programme and points owners to EPA, so the API 653 obligation comes from EPA's SPCC rule, PHMSA's breakout-tank rule, OSHA process safety management and owner standards. Atlantis performs the NDE behind the inspection, floor MFL with UT prove-up, shell UT, weld examination and settlement data, and delivers it to your inspector in a digital report.

Mississippi's tanks tell a story of two corridors. On the coast, the Pascagoula refinery and the Bayou Casotte industrial harbour hold the state's largest single tank population, with Gulfport, Pass Christian and the military bases close by and a long memory of hurricane storm surge. Inland, the town of Collins in Covington County is one of the most important petroleum hubs in the Southeast, where the Colonial Pipeline stores northbound product in a large tank farm and several other pipeline and wholesale companies keep bulk storage. Add refineries at Vicksburg and Sandersville, Mississippi River port terminals, fertilizer plants in the Delta and production tanks in the southern oil fields, and you have a state where the right inspection approach depends heavily on who regulates each tank. This page sets that out. Atlantis performs the NDE; your API 653 Authorized Inspector remains inspector of record and signs the inspection report. To start, send us your Mississippi tank list.

Where API 653 tanks are in Mississippi

Direct answer: Mississippi's field-erected steel tanks are concentrated at the Pascagoula refinery and Bayou Casotte harbour, at the Collins pipeline and wholesale hub, at refineries in Vicksburg and Sandersville, at Gulfport and Mississippi River port terminals, at fertilizer and chemical plants, and at power stations, military fuel farms and southern oil-field facilities.

Pascagoula and Jackson County

Chevron's Pascagoula refinery is the largest refinery in Mississippi and one of the larger refineries in the country, with crude, intermediate and product tankage on the east side of Pascagoula and a marine terminal that receives crude by tanker. Bayou Casotte also hosts the Gulf LNG terminal, whose full-containment LNG tanks are built to low-temperature standards rather than API 650 and therefore sit outside API 653, along with chemical and industrial facilities. Shipbuilding at Pascagoula is the state's largest private employer and stores fuels and coatings materials on site. Salt air, a high water table and soft coastal soils make soil-side floor corrosion and settlement the defining issues here.

Collins: the inland pipeline hub

Collins is where much of the gasoline and distillate moving north on the Colonial Pipeline is stored before it continues toward the Southeast and Mid-Atlantic. Colonial's Collins tank farm alone is listed with a dozen large tanks, and the town is also home to tank farms operated by other pipeline, terminal and wholesale companies. Many of these are breakout tanks on interstate hazardous-liquid pipelines, which makes them some of the most closely regulated tanks in the state, with PHMSA requiring API 653 inspection and limiting how the internal interval can be set. Rural inland soils, heavy rainfall and older tank vintages make floor condition, shell-to-bottom corrosion and foundation drainage recurring themes.

Vicksburg, Sandersville and the refining interior

Ergon operates a refinery at Vicksburg on the Mississippi River that specialises in naphthenic oils and asphalt, and Hunt Southland Refining operates at Sandersville near Laurel. Specialty and asphalt refineries use heated, insulated tanks where corrosion under insulation and thermal cycling at the shell-to-bottom joint are bigger concerns than in ambient product storage. River-port terminals at Vicksburg, Natchez and Greenville handle fuels, asphalt and agricultural liquids.

Gulfport, Pass Christian and the coast

The Port of Gulfport handles bulk cargoes, and Gulfport, Biloxi and the coastal counties host fuel terminals, Keesler Air Force Base and the Naval Construction Battalion Center with their own fuel storage. At DeLisle, near Pass Christian, a large titanium dioxide plant stores acids and process liquids. Coastal tanks share Pascagoula's exposure to salt air, storm surge and flooding.

Fertilizer, power and the oil fields

CF Industries' Yazoo City complex produces nitrogen fertilizers, and nitrogen solution and other liquid fertilizer products are commonly stored in large carbon-steel tanks that owners often manage under API 653 principles. Mississippi Power and Entergy plants, including Grand Gulf Nuclear Station near Port Gibson, store fuel oil and treatment chemicals. In the southern half of the state, oil fields around Laurel and in southwest Mississippi use production tank batteries that normally follow API RP 12R1 rather than API 653. Confirming each tank's construction standard is always the first step.

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 requires monthly owner checks, an Authorized Inspector's external inspection at least every five years, shell UT surveys and an out-of-service internal inspection on intervals tied to measured corrosion. The current Fifth Edition carries addenda through Addendum 4 (July 2025).

Routine in-service checks. Owner personnel inspect each tank at least monthly for leaks, distortion, settlement, coating and roof problems and foundation damage. In Mississippi's climate that includes checking floating-roof drains and rainwater after heavy storms.

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

Shell UT thickness. Where UT readings are used, they are required 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. A new tank's first internal inspection is due within ten years, extendable by credited safeguards up to twenty years without a release prevention barrier or thirty with one. Later intervals are calculated from measured bottom corrosion within the same ceilings, or set by a qualifying risk-based assessment done by the owner's specialists. For a PHMSA breakout tank, that risk-based option is not available for the internal interval.

Settlement and repairs. The code's settlement annex, brittle-fracture screening and repair rules complete the picture. Addendum 4 revised the text on measuring tank-bottom plate thickness, so check procedures against the current edition from api.org. See API 653 tank inspection intervals explained and the API 653 tank inspection guide.

Mississippi regulations that sit on top of API 653

Direct answer: Mississippi has no state aboveground tank programme; MDEQ states that aboveground tanks are regulated by EPA. In practice API 653 is required through EPA's SPCC rule, PHMSA's breakout-tank rule (PHMSA directly regulates hazardous-liquid pipelines in Mississippi), OSHA PSM and owner policy. Propane tanks fall to the Mississippi Insurance Department, and local fire marshals may add rules.

MDEQ and the absence of a state AST rule

MDEQ runs an underground storage tank programme but not an aboveground one. Its guidance tells owners that aboveground tanks are regulated by EPA, that aboveground propane tanks are regulated by the liquefied compressed gas division of the Mississippi Insurance Department, and that local fire marshals and city and county governments may have their own requirements. That puts more weight on federal rules and on the owner's own engineering standards than in states with a dedicated AST rule. Facilities with environmental permits from MDEQ may still find tank conditions written into those permits, so check your permits as well as the federal rules.

EPA SPCC through EPA Region 4

For most Mississippi terminals, distributors, plants and farms above the threshold, the governing requirement is EPA's Spill Prevention, Control and Countermeasure rule, 40 CFR Part 112, enforced by EPA Region 4. Bulk storage containers must be tested or inspected 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. The SPCC plan should name the standard for each tank and the next due date, and the inspection records need to be kept with the plan.

PHMSA directly regulates hazardous-liquid lines

Under 49 CFR 195.432, steel aboveground breakout tanks on regulated hazardous-liquid pipelines operating at atmospheric or low pressure must be inspected in accordance with API 653, excluding the code's alternative risk-based internal interval; pressurised breakout tanks follow API 510. In Mississippi, PHMSA's Office of Pipeline Safety inspects and enforces the rules for both interstate and intrastate hazardous-liquid pipelines, while the Pipeline Safety Division of the Mississippi Public Service Commission handles intrastate natural gas systems under PHMSA certification. The Collins breakout tanks and pipeline-connected tanks around Pascagoula therefore answer to PHMSA directly.

OSHA PSM, boilers and pressurised storage

Mississippi has no OSHA State Plan for private employers, so federal OSHA enforces 29 CFR 1910.119. At the refineries, chemical and fertilizer plants with covered processes, mechanical integrity requires inspection and testing following recognised and generally accepted good engineering practices, and API 653 is the practice cited for atmospheric tanks. Pressurised storage such as LPG bullets and spheres is a different matter: it falls under API 510 and the Mississippi State Department of Health's Boiler and Pressure Vessel Safety Branch, not under API 653.

Radiography in Mississippi

Mississippi has been an NRC Agreement State since 1962, and industrial radiography licences are issued by the Mississippi State Department of Health's Division of Radiological Health. Repair-weld radiography is performed only by crews properly licensed for work in Mississippi.

NDE methods for API 653 work in Mississippi

Direct answer: Mississippi tank work relies on floor MFL scanning with UT prove-up, shell and annular-plate UT, corrosion mapping on coastal and insulated tanks, visual examination of roofs, seals, drains and foundations, MT, PT and vacuum-box testing after repairs, PAUT or RT on new welds, and settlement data for the inspector.

Procedures are reviewed by an ASNT NDT Level III and technicians are certified to an SNT-TC-1A written practice for each method. Every reportable MFL indication is proved up with UT. Mississippi's expansive clays in the central and northern counties can move foundations seasonally, so settlement data is worth collecting even where the floor looks sound. For the floor-method trade-offs see MFL versus UT for tank floors, and for the full scope 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 NDE, checks the data before leaving site and delivers a digital report for the inspector's evaluation and signature. We are not an Authorized Inspection Agency and we do not supply API-certified inspectors. For PHMSA-regulated breakout tanks in particular, independent, traceable NDE data makes the operator's records stronger.

1. Scope from the inspector's plan: floor coverage, shell and annular-plate locations, roof, seal and foundation examinations, weld examinations and settlement points.
2. Procedure review by an ASNT NDT Level III, matched to the tank's construction standard and the inspector's acceptance references.
3. 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.
4. Data QA on site: readings checked against calibration records and the last inspection before demobilising.
5. Digital report in our reporting platform: floor maps, prove-up readings, shell readings by course, weld records, photographs, calibration data and technician certifications, on report templates that suit your inspector's file and your SPCC or PHMSA records.
6. Inspector evaluation and sign-off: the inspector evaluates the results, decides on repairs and sets the next dates.
7. Reuse at the next interval: the same locations next time, tracked in our inspection-management ERP or a digital twin of the tank farm.

Corrosion rates and remaining life can be calculated from our thickness data for the inspector's review; the interval decision is the inspector's and the owner's under API 653 and the federal rule that applies. 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 see API 653 tank inspection support.

Planning around storms, pipeline cycles and turnarounds

Direct answer: On the Mississippi coast, out-of-service tank work is usually kept away from the peak of hurricane season, and inland at Collins it is scheduled around pipeline batch cycles and the operator's tank rotation. External UT, mapping and visual work can run year-round, but internal inspections need cleaning, NDE and repair planned as one sequence.

Storm surge and the coast. Hurricane Katrina's storm surge in 2005 devastated the Mississippi coast, and Camille in 1969 before it. An empty tank opened for internal inspection can float or shift in surge, so coastal owners avoid having large tanks out of service in the peak months or plan to ballast them with water when a storm approaches. After a storm, owners and inspectors typically want shell, roof, seal and foundation checks before normal operation, and Atlantis can collect that data as soon as the site is safe.

Collins and pipeline tank rotation. At a pipeline hub, tanks are taken out of service one at a time while the others carry the throughput, so internal inspections follow a rotation agreed with pipeline scheduling. Out-of-service time is expensive for the operator, and the most useful thing the NDE crew can do is arrive when cleaning finishes, scan and prove up quickly, and give the inspector clean data the same week.

Refinery turnarounds. At Pascagoula, Vicksburg and Sandersville, tank work is often tied to unit turnarounds and product slates. Heated asphalt tanks need cool-down time and insulation removal before UT, which should be in the schedule from the start.

Rain and heat. Mississippi's heavy rainfall affects floor work, containment drainage and access, and summer heat affects technicians inside tanks. Ventilation, early starts and temperature-corrected UT readings are routine. Book a scoping call to fit inspections into your rotation.

API 653 inspection support across Mississippi

Direct answer: Atlantis mobilises crews to tank sites anywhere in Mississippi on a schedule agreed during scoping: Pascagoula and Bayou Casotte, Gulfport and the coast, Collins, Laurel and Sandersville, Jackson, Vicksburg, Natchez and the river ports, and the Delta.

• Pascagoula and Jackson County: refinery and marine terminal tankage, industrial storage at Bayou Casotte and the shipyard.
• Collins and Covington County: breakout tanks and wholesale tank farms on the Southeast's pipeline hub.
• Gulfport, Biloxi and Pass Christian: port and fuel terminals, military fuel farms and chemical storage.
• Vicksburg, Natchez and Greenville: refinery, asphalt and river-port tanks.
• Laurel and Sandersville: refinery tanks and oil-field facilities.
• Jackson and the Delta: distribution terminals, fertilizer plants and agricultural liquid storage.

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

What to send us for a quote

Direct answer: Send your tank list, the last API 653 reports, your inspector's plan, access and cleaning status, and your target dates. 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, plate thicknesses, bottom history, cathodic protection, leak detection, and whether the tank is a PHMSA breakout tank, inside a PSM-covered process or under an SPCC plan.
2. Previous reports: external and internal API 653 reports, floor maps, shell readings and settlement surveys.
3. The inspector's plan: examinations, coverage, acceptance references and report format, with the name of your Authorized Inspector or agency.
4. Access and cleaning: in service, emptied or cleaned and gas-free, scaffold and confined-space arrangements, site orientation and permits.
5. Dates: regulatory due dates, pipeline rotation or turnaround windows and storm-season constraints.

Get a quote within 24 hours.

Frequently asked questions: API 653 tank inspection in Mississippi

Who can perform an API 653 inspection in Mississippi?

An API 653 Authorized Inspector, employed by the owner or 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.

Does Mississippi have its own aboveground storage tank regulations?

No general state AST programme exists. MDEQ states that aboveground tanks are regulated by EPA, propane tanks fall to the Mississippi Insurance Department, and local fire marshals may have requirements. Check any MDEQ environmental permit for tank conditions too.

Is API 653 required by law in Mississippi?

It is required in effect wherever EPA's SPCC rule, PHMSA's breakout-tank rule at 49 CFR 195.432 or OSHA PSM applies, and wherever the owner's standard adopts it. Confirm which rule covers each tank in your SPCC plan or pipeline procedures.

Who regulates the breakout tanks at Collins?

PHMSA. It regulates both interstate and intrastate hazardous-liquid pipelines in Mississippi directly, and its rule requires API 653 inspection of steel atmospheric breakout tanks without the code's risk-based internal interval. The Mississippi Public Service Commission covers intrastate gas pipelines.

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

Monthly owner checks, an external inspection at least every five years, shell UT on an interval set by corrosion rate, and an internal inspection first due within ten years, then on a calculated interval within the code's ceilings. The inspector sets the dates.

Should coastal tanks be opened during hurricane season?

Many owners avoid it in the peak months because an empty tank can float in storm surge. If an internal has to happen then, plan water ballast and a storm procedure. External work can usually continue.

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.

Can you inspect while the tank stays in service?

Yes, for shell UT, corrosion mapping, visual examination of the shell, roof and foundation, and settlement data. Floor scanning needs the tank emptied and cleaned.

What certifications do your NDE technicians hold?

Technicians are certified to an ASNT SNT-TC-1A written practice for each method, with procedures reviewed by an ASNT NDT Level III. Radiography is performed only by crews licensed through the Mississippi State Department of Health.

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

No. Those are carried out by the owner's engineers or specialist consultants. Atlantis supplies the floor, shell and weld data they use. Remember that PHMSA breakout tanks cannot use API 653's risk-based internal interval.

Do you offer API 653 certification training?

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

How quickly can a crew reach Pascagoula or Collins?

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

Plan your Mississippi tank inspections

From a floor scan on a Collins breakout tank to a shell survey at a Gulfport terminal or a settlement check on a Vicksburg asphalt tank, start with your inspector's plan and your outage window. Send us your tank list, or see NDT consulting in Mississippi for Level III procedure support.

More Atlantis NDT services in Mississippi

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

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