Safe Tank Services Infrastructure
Intelligence
STS / Underground Fuel Storage Render · 4″ probe
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Infrastructure intelligence for underground fuel storage

Replace the tanks that need it.
Keep the ones that don't.

STS reads the structural condition of underground tanks while they stay full and in service, so replacement decisions are based on the tank itself, not the calendar.

Magnetostrictive
guided wave · MsT / GWT
Single probe
full wall
Nominal wall 6.35 mm
resolved end to end
/ The method, rendered

Read the whole wall
from a single probe.

Method MsT / GWT Mode Torsional Coverage 100% wall Downtime None
Scroll to scan
100%
Of the tank wall read
from a single probe
1
Structural Condition
Record, per tank, for life
0
Active underground tanks
nationwide, EPA-tracked
SwRI
Method developed and
peer-reviewed validation
01 The problem with age

Age tells you how old a tank is. It doesn't tell you if it's failing.

Once a tank is buried, its condition is invisible. That leaves operators guessing in two directions at once, and both guesses are expensive.

Replace too early

/Capital spent on a site that had years left.

/Disruption for no reason.

/Budget consumed that a failing site needed.

Replace too late

/Release and remediation.

/Downtime and regulatory exposure.

/A brand story you do not control.

Both mistakes come from the same gap. Once a tank is buried, condition is invisible, so age becomes the only variable anyone can act on.

02 Why this is different

No product drop. No dispensers down. No lost sales days.

01 / Tank out

Every other way to learn something about the tank wall starts by emptying and cleaning the tank and closing the site.

02 / Leak testing

Testing that runs while you stay open only tells you whether a tank is leaking today, not whether it is going to fail.

03 / STS

STS gives you structural condition with the site fully operating.

03 How the method reads a tank

One probe, through the drop tube, reading the whole wall.

Magnetostrictive guided wave (MsT / GWT) sends a torsional wave along the tank wall from a single probe lowered through the existing 4-inch drop tube. The wave travels the full structure and returns a signal that maps wall condition, end to end, with the tank full and in service.

01
Deploy through the drop tube
No excavation, no tank removal, no downtime. The probe enters through hardware already on site.
02
Propagate a guided wave
A torsional wave travels the wall and reflects off changes in thickness, corrosion, and discontinuities.
03
Resolve condition, issue a record
The return maps the wall and produces a Structural Condition Record that follows the tank.
FIG.02 / CROSS-SECTION, GUIDED WAVE DEPLOYMENT
GRADE
STEEL TANK WALL, FULL & IN SERVICE
EXISTING
4″ DROP TUBE
SINGLE
MsT PROBE
→ READS 100% OF WALL
ZERO DOWNTIME ←
Validation status, stated plainly
Validated
Steel tanks
Method developed and peer-reviewed at Southwest Research Institute on steel.
In validation
In-service underground deployment
Deployment through the drop tube on live underground tanks is under active validation.
In validation
Fiberglass tanks
Application of the method to fiberglass is in validation, not yet proven.
04 The record that compounds

Every read becomes a Structural Condition Record.

A dated, data-backed record of condition that follows the tank for the rest of its life. It informs the next replace-or-keep decision, it travels to a buyer or lender at site transfer, and it gives an agency a defensible basis for condition.

Across thousands of tanks, those records compound into the category's structural dataset: a reference for what condition actually looks like underground, by tank type, age, and region.

Structural Condition RecordSTS-CSH-024187
Structurally sound
Tank type
Steel, single-wall
Read on
2026.05.18
Min wall remaining
5.82 mm
Method
MsT / GWT
Recommendation
Keep in service, re-read 2029
05 The output

Every tank comes back with one of three answers.

Replace

The wall has lost enough section that the tank should come out. The work gets scheduled with evidence behind it.

Monitor

Condition is acceptable today, with change worth tracking. Read again on a set interval and watch the trend.

Keep

The wall is sound. The tank stays in service and the capital goes where a tank actually needs it.

Each answer is recorded in the Structural Condition Record, so the reasoning stays with the tank and not in someone's memory.

// In the field

Read while the site keeps selling fuel.

A read happens with the tank full and the forecourt open. No tank-out, no excavation, no lost trading hours.

06 Who reads the record
Primary focus

Operators

C-store chains and fleets carrying hundreds of tanks. A read tells you which tanks are sound and which are failing, so replacement capital lands on the sites that need it and the network keeps trading.

Decision / replace, monitor, or keep
Stakeholder

Manufacturers

Field condition data on how their tanks age in the ground, by type and region.

Stakeholder

Agencies & programs

Regulators gain a defensible, condition-based basis rather than age alone.

Stakeholder

Buyers & lenders at site transfer

A Structural Condition Record turns an unknown buried asset into a documented one, de-risking diligence when a site changes hands.

Origin
Southwest Research Institute

The method was developed and validated at SwRI, with peer-reviewed results on steel.

Standards
ASTM · WK90823

STS holds a seat on the ASTM committee shaping how this method is standardized.

Scale
0 tanks

Active underground fuel tanks in service nationwide, tracked by the EPA.

/ Contact

Get in touch.

Questions about the method, the validation work, or a tank you are deciding on. One site is enough to start, and a read returns a Structural Condition Record that follows the tank for life.

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