Hazardous Substance Removal (HAZ) · Lesson 5 of 6

Out-of-Service Tanks: The 90-Day, One-Year and 365-Day Clocks

"Out-of-Service Tanks: The 90-Day, One-Year and 365-Day Clocks" is lesson 5 of 6 in the Hazardous Substance Removal (HAZ) Learning Hub. It opens with "Two Rulebooks Run at Once" and works through 6 short steps, then a worked example you can check yourself against.

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Steps in this lesson

  1. Two Rulebooks Run at Once
  2. The CFC 90-Day Safeguard
  3. The CFC One-Year Rule and Abandonment in Place
  4. 23 CCR Temporary Closure: 12 Months, Maybe 24
  5. 23 CCR Permanent Closure Deadlines
  6. The Removal Checklist (CFC 5704.2.14.1)

The worked example in the course applies this lesson to a realistic job in 5 steps, starting with "CFC one-year mark".

What you'll be able to do

  • Explain the main idea of "Out-of-Service Tanks: The 90-Day, One-Year and 365-Day Clocks" in plain language you can use on the exam.
  • Apply this step with confidence: "The CFC One-Year Rule and Abandonment in Place".
  • Apply this step with confidence: "23 CCR Temporary Closure: 12 Months, Maybe 24".
  • Apply this step with confidence: "23 CCR Permanent Closure Deadlines".
  • Apply this step with confidence: "The Removal Checklist (CFC 5704.2.14.1)".
  • Test yourself on the worked example and the quick-check quiz inside the classroom.
Out-of-Service Tanks: The Closure ClocksFIRE CODE (2025 CFC 5704.2.13)Mar 1, 2026storage stopsMay 30, 2026day 90: safeguard or removeMar 1, 20271 yr: remove or abandonTANK REGULATIONS (23 CCR 2681)Apr 15, 2026proposal filed (day 45)Jun 1, 2026UPA approvesJun 1, 2027365-day limitREMOVAL AND PAPERWORK (23 CCR 2681(i), (k))Feb 10, 2027tank removedMar 12, 2027documents due (30 d)May 11, 2027Closure Letter (60 d)Finish removal before Mar 1, 2027: the earlier clock satisfies bothCFC: 90 days safeguard or remove; one year remove or abandon in place23 CCR: apply within 90 days of cessation; finish within 365 days of approvalRed dots are the hard limits; gold dots are agency or paperwork steps2025 CFC §5704.2.13-14; 23 CCR §2680-2681CC
The diagram for this lesson, exactly as it appears in the Learning Hub.

The first steps of this lesson

Step 1: Two Rulebooks Run at Once

A tank taken out of service answers to the fire code and to the state tank regulations. 2025 CFC §5704.2.13 says tanks taken out of service shall be removed under §5704.2.14 or safeguarded under §§5704.2.13.1 through 5704.2.13.2.3 and API 1604. 23 CCR Chapter 16 Article 8 (§2680 temporary closure, §2681 permanent closure) is administered by the Unified Program Agency (UPA). A HAZ contractor has to keep both clocks in view, because the shorter one controls when work must be finished.

Step 2: The CFC 90-Day Safeguard

Under 2025 CFC §5704.2.13.1.2, an underground tank not used for 90 days must either be removed per §5704.2.14 or be safeguarded: (1) flammable or combustible liquids removed from the tank; (2) all piping, including fill line, gauge opening, vapor return and pump connection, capped or plugged and secured from tampering; (3) vent lines left open and maintained. While a tank is only temporarily out of service, §5704.2.13.1.1 requires the fill line, gauge opening, vapor return and pump connection to be secure against tampering with vent lines remaining open.

The remaining 4 steps, the worked example and the quiz are in the course. This is a preview. The full lesson, with the step-by-step explanations, a worked example and a quick-check quiz, is inside the classroom.

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