In the SPCC regulations in 40 CFR 112, what is the difference between a Tier I and Tier II qualified facility?

A Tier II qualified facility is one that has an aggregate aboveground oil storage capacity of 10,000 U.S. gallons or less and meets the oil discharge history criteria in 112.3(g)(2). To qualify as a Tier I qualified facility, in addition to meeting the eligibility criteria for a Tier II qualified facility, a facility must have no individual aboveground oil storage containers with a capacity greater than 5,000 U.S. gallons (see 112.3(g)(1)).

The owner or operator of either a Tier I or Tier II qualified facility may self-certify the facility’s Spill Prevention, Control, and Countermeasure (SPCC) plan, as provided in 112.6. The owner or operator of a Tier I qualified facility also has the option to complete and implement a streamlined, self-certified SPCC plan template available in Part 112, Appendix G. The template does not include certain requirements that are inapplicable or unnecessary, and Tier I qualified facilities are subject to streamlined requirements for failure analysis, bulk storage secondary containment, and overfill prevention (see 112.6(a)(3)).