It's 6 a.m., and the tank gauge reads SUDDEN LOSS on Tank 2. Before anyone touches the console, the manager writes it down and asks one question: was a fuel truck unloading while the leak test ran? One was. The test runs again and passes, and a one-line note closes it out.
A gauge can show dozens of alarm messages, and the names change from one model to the next. The federal rules care about a few groups of them. Here is which ones, what each means, how fast to act and what to do first.
An Alarm Is a Suspected Release Until Someone Shows It Isn't
Federal UST rules treat a release detection alarm as a possible leak. Under 40 CFR 280.50(c), monitoring results, "including investigation of an alarm," that show a release may have occurred go to your state agency within 24 hours. Section 280.52 then says to investigate right away and confirm within 7 days.
There is a way out, and it runs through a person. No report is needed if the alarm "was investigated and determined to be a non-release event." The rule gives two examples: a power surge, or filling the tank during a leak test. It also excuses a faulty monitor that is "immediately repaired, recalibrated or replaced," as long as more monitoring doesn't confirm the first result.
So the clock starts when the alarm sounds. A written investigation is what stops it.
The First Five Minutes
When the console beeps, do these in order.
Write down the alarm name and the time. Do it before anyone touches the console. Once the screen clears, the details are easy to lose.
Check the obvious causes. Was fuel being delivered? Was fuel being sold while a test ran? Was there a recent power outage or surge?
Silence the beep, but don't clear the alarm without a note. Silencing is fine. Clearing an alarm with nothing written down is how investigations never happen.
Look the alarm up and do what it says. The lookup below tells you whether to run the test again or check a sensor.
If a leak result holds up, call your service provider. Remember the clock above: a possible release goes to your state within 24 hours, unless an investigation shows it isn't one.
Pick any alarm in the lookup below. It shows what the alarm means, how serious it is, what to do and who to call.
UST Compliance Tools
ATG Alarm Lookup
Pick the alarm on your tank gauge. See what it means, whether federal rules treat it as a possible release, what to do, and who to call. Alarm names differ by gauge, so other names are listed under each one.
Leak Alarms: Run the Test Again, Then Call
Several alarms say one thing: the tank lost product during a test. They include the leak alarm, a periodic or annual leak test fail, a gross leak test fail and the sudden loss alarm. A line leak detector failure says the same about the piping. Federal rules require a gauge test that can find a leak of 0.2 gallon per hour, run at least once every 30 days or continuously (280.43(d)).
First, check whether fuel was delivered or sold during the test. That is the most common innocent cause, and the rule names it. If nothing explains the loss, run the test again. A second failure goes to your service provider. Unless they find a cause that isn't a leak, it goes to your state too.
Sensor Alarms: Find Out What the Liquid Is
Sensors watch the space between a tank's two walls and the sumps under the pumps and dispensers. A fuel alarm means the sensor found product. A water alarm means water. A plain liquid alarm means something is there, and nobody knows what yet.
The federal rule lists "liquid in the interstitial space of secondarily contained systems" as a condition you must report (280.50(b)). You skip the report only if the liquid is removed right away and any faulty part is fixed right away. Fuel in a sump is a call to your service provider today.
Tank Levels: Water, Overfill and Low Product
A high water alarm means the water at the bottom of the tank passed your set limit. The rule names "an unexplained presence of water in the tank" as a reportable condition (280.50(b)). Find where the water came from. Our water story shows how to read the trend before it gets that far.
Overfill, high product and maximum product alarms fire during deliveries. Stop the delivery. If your site uses the gauge's high-level alarm as its overfill protection, it must warn the driver when the tank is "no more than 90 percent full" (280.20(c)). A spill over 25 gallons, or one that leaves a sheen on nearby water, must be cleaned up at once and reported within 24 hours (280.53).
Low product and delivery needed alarms are mostly about running out. But a nearly empty tank can keep a gauge from finishing a valid leak test. Don't let one sit there.
The Quiet Alarms Are the Ones Inspectors Find
Some alarms don't mean something is leaking. They mean nothing is being checked.
Periodic or annual test needed: the gauge hasn't finished a passing test in its set window.
Probe out: the tank probe has failed, so the gauge can't measure that tank.
Sensor out, short or open: a sensor or its wiring has failed.
No reply: the gauge can't hear a sensor or module.
Setup data warning: the gauge found a problem in its own settings.
Each one opens a gap in release detection. Federal rules require tanks to be monitored "at least every 30 days" (280.41). The monthly walkthrough must confirm release detection "is operating with no alarms or other unusual operating conditions present" (280.36). A gap becomes a missed month fast. Treat these as repair calls, not reminders.
Write Down What You Did
Under 280.45, monitoring results are kept for at least one year. Records of calibration, maintenance and repair of release detection equipment are kept for at least one year after the work. The yearly test that the gauge's alarms work, required by 280.40(a)(3), is kept for three years.
For each alarm, write one line. Here is one you can copy:
Oct 27, 6:05 AM — SUDDEN LOSS, Tank 2. Checked: delivery in progress during test. Re-ran test: passed. No report needed. — J. Smith
And the fill-in version:
Date, time — Alarm name, tank or sensor. Checked: what you found. Action: what you did. Reported: no, or yes and to whom. — Your name
That line is your proof the investigation happened.
Pressing clear doesn't close the question. Your monitoring records (280.45) are what an inspector reads, and an alarm with no note beside it is a question you'll have to answer later. Our May story shows how that ends.
Your State May Set a Shorter Clock
The 24-hour reporting rule reads "24 hours, or another reasonable period specified by the implementing agency." The other timelines above carry the same kind of words. The implementing agency is usually your state. States can set their own windows, amounts and record periods. Check yours. The agency finder in our storm-season story lists each state's agency and release-reporting contact.
Across many sites, someone also has to see every alarm. In PASS Harmonics ATG Connect, each alarm becomes an incident with an urgency and an owner. A gauge that hasn't reported in four hours is marked Outdated, so a quiet gauge isn't mistaken for a quiet site.
The Bottom Line
Most alarms are not emergencies. The rules still expect you to prove that, one alarm at a time. Treat every leak and sensor alarm as a possible release until someone investigates and writes down what they found. Treat the quiet alarms as repairs. Keep the record.
ATG Connect is part of PASS Harmonics. Alarms, incidents and release detection records sit on the same facility record as your inspections and paperwork. See PASS Harmonics
Not sure which alarms your state counts, or how fast it wants a report? Ask us.
