One section of the federal rule covers three pieces of equipment that sit in different parts of the site. 40 CFR 280.35 handles spill prevention equipment, containment sumps used for interstitial monitoring of piping, and overfill prevention equipment. All three run on a three year cycle, one of them has an exemption most modern sites qualify for, and one of them Connecticut wants annually instead.
The three year liquid tight test
Spill prevention equipment means the bucket under the fill cap, whatever your site calls it. A catchment basin, a spill bucket, or any other spill containment device. Under 280.35(a)(1)(ii) it gets tested at least once every three years to establish that it is liquid tight, using vacuum, pressure, or liquid testing.
Containment sumps get the same test on the same interval, with one limit on scope worth reading carefully. The rule says containment sumps used for interstitial monitoring of piping, and that phrase appears every time sumps are mentioned in the section. A sump that plays no part in your release detection method is outside this requirement. It still gets the annual visual under 280.36.
Double walled equipment can skip it
280.35(a)(1) offers two ways to satisfy the requirement, and the first one is not a test at all.
If the equipment is double walled and the integrity of both walls is periodically monitored at a frequency no less than the walkthrough inspections in 280.36, the three year test does not apply. Since walkthroughs run every 30 days, that means monitoring both walls at least monthly.
The exit clause is the part to note. Owners and operators must begin meeting the testing requirement and conduct a test within 30 days of discontinuing periodic monitoring. Monitoring that quietly stops, because a sensor failed or a console was replaced, starts a 30 day clock that nobody set. Record retention follows the same logic: for equipment relying on the monitoring exemption, 280.35(c)(2) says keep the documentation showing it is double walled and monitored for as long as the equipment is in use.
Overfill prevention is an inspection, and it has to activate
Overfill prevention equipment is inspected at least once every three years under 280.35(a)(2). The inspection has to establish two things: that the equipment is set to activate at the correct level specified in 280.20(c), and that it will activate when regulated substance reaches that level.
The second half is what separates an inspection from a look. A flapper valve that appears intact and sits at the right depth has satisfied the first half only. Demonstrating that it operates is the requirement, and it is why this one usually needs somebody with the right equipment rather than a set of eyes.
Who decides how the test is done
The rule does not prescribe a procedure. It gives you three sources to pick from, in 280.35(a)(1)(ii)(A) through (C):
- Requirements developed by the manufacturer, usable only if the manufacturer has actually developed them.
- A code of practice developed by a nationally recognized association or independent testing laboratory.
- Requirements determined by your implementing agency to be no less protective of human health and the environment.
The rule names Petroleum Equipment Institute RP1200 as a code of practice that may be used for both the tests and the overfill inspection. Most testing contractors work to it, and asking which of the three options a contractor's report is written against is a fair question before you book them.
Connecticut adds a subtraction to this list. DEEP has determined that dri-sump testing using vapor tubes or aerosolized fog, and low liquid level UST containment sump testing, are unacceptable methods in that state. A method being a recognized practice somewhere does not make it acceptable everywhere.
When the clock started
For systems in use on or before October 13, 2015, the initial spill prevention test, containment sump test and overfill inspection were due not later than October 13, 2018. For systems brought into use after October 13, 2015, the requirements applied at installation.
Three year cycles from those dates put most sites on a 2024 or 2027 rotation, and a site that has changed hands since 2018 is worth checking. A buyer who inherited a site mid-cycle inherited its dates too, and the previous owner's test reports are the only evidence of when the clock last reset.
Records: three years, and one that is longer
280.35(c) sets two retention rules. All records of testing or inspection are kept three years. Documentation for double walled equipment relying on the monitoring exemption is kept for as long as the equipment is in use.
Note the contrast with the walkthrough records under 280.36, which are kept for one year. Three retention periods live in the same part of the same rule, and a binder cleared out on a single schedule will be missing something.
Where your state asks for more
Connecticut is the published example we can check. Its periodic testing table sets overfill equipment testing at annual, under RCSA 22a-449(d)-103(g)(2), for every tank category on the table. The federal rule asks for three years. An operator who set that date from 40 CFR 280.35 is two years behind on every cycle, and has been since the state's schedule took effect.
The liquid tight test on STPs, under-dispenser containment and spill buckets stays at three years in Connecticut, under 103(e)(2), matching the federal interval. Secondary containment testing on tank and piping interstices is also three years, under 103(d)(2), with exemptions for double walled components under continuous interstitial monitoring.
Two requirements from one federal section, one matching the state and one not. Reading the federal rule and stopping there is how a site ends up compliant on paper in the wrong jurisdiction.
How FastDragon handles it
These three land as separate items on the calendar because they are separate requirements with separate evidence, even though one contractor visit often closes all three. The interval comes from the site's state, so a Connecticut site gets the annual overfill inspection and the three year sump test rather than three years for both.
Where equipment is double walled and monitored, the item is switched off against that site with the reason recorded, so the next person can see why it is quiet rather than assuming it was forgotten. Marking a test done asks for the report and files it against the requirement, and the next date is computed from the day the work was signed off.
Common questions
My spill buckets are double walled. Do I still test every three years?
Not while you are monitoring them. 40 CFR 280.35(a)(1)(i) lets double walled spill prevention equipment and containment sumps skip the three year test if the integrity of both walls is monitored at least as often as the walkthrough inspections in 280.36. Stop that monitoring and the clock starts: you have 30 days to conduct a test. Keep the documentation showing the equipment is double walled and monitored for as long as the equipment is in use, per 280.35(c)(2).
Which containment sumps does the three year test apply to?
Only sumps used for interstitial monitoring of piping. That is the wording throughout 280.35, and it matters. A sump that is not part of your release detection method is outside this particular requirement, though it still gets the annual visual check under 280.36(a)(1)(ii).
What does the overfill inspection have to establish?
Two things, under 280.35(a)(2). That the equipment is set to activate at the correct level specified in 280.20(c), and that it will activate when product reaches that level. A visual look at a flapper valve does not answer the second one. The inspection has to demonstrate the device operates.
Who decides how the test is done?
You pick from three options in 280.35(a)(1)(ii): the manufacturer's requirements, and only if the manufacturer has developed them; a code of practice from a nationally recognized association or independent testing laboratory; or requirements your implementing agency has determined are no less protective. The rule names Petroleum Equipment Institute RP1200 as a code of practice that may be used.
Does Connecticut follow the three year federal interval?
On sumps and spill buckets, yes. On overfill, no. Connecticut's periodic testing table puts overfill equipment testing at annual under RCSA 22a-449(d)-103(g)(2), across every tank category, where the federal rule asks for three years. The liquid tight test on STPs, under-dispenser containment and spill buckets stays at three years under 103(e)(2). Operators who set that date from the federal rule are two years late every cycle.