EPA SPCC Rule (40 CFR 112): Secondary Containment Requirements

Overview

The Spill Prevention, Control, and Countermeasure rule, codified at 40 CFR Part 112, is the EPA regulation that requires certain facilities storing oil to prevent oil from reaching navigable waters and adjoining shorelines. It is a prevention rule, not a cleanup rule: the central obligation is to plan for and physically contain a discharge before it leaves the facility. The rule traces back to the Clean Water Act and is administered by the EPA under the broader oil pollution prevention regulations.

SPCC covers a wide definition of oil: petroleum and non-petroleum oils, fuels, lubricants, hydraulic fluids, and animal and vegetable oils. The most visible requirement, and the one that drives most equipment buying, is secondary containment: a backup barrier such as a containment pallet, a dike, or a curbed area that catches oil from a leaking or ruptured container so it does not run off the site.

The full regulation text is published in Title 40, Part 112 of the Electronic Code of Federal Regulations. This page summarizes the parts of the rule that govern who must comply and how containment is sized. It is a plain-language overview, not legal advice, and your facility's plan should be prepared or reviewed against the current rule and, where required, certified by a Professional Engineer.

Who Must Comply (Applicability)

A facility is subject to SPCC when it meets all three of the following conditions under 40 CFR 112.1:

• It is non-transportation-related and stores oil. Farms, manufacturers, fuel distributors, warehouses, fleet yards, and similar fixed facilities are covered; vehicles in transit are regulated under DOT rules instead.
• It exceeds an oil storage capacity threshold. The aggregate aboveground oil storage capacity is more than 1,320 US gallons, or the completely buried storage capacity is more than 42,000 US gallons. Capacity, not the amount on hand, is what counts.
• There is a reasonable expectation of a discharge to water. Because of the facility's location, a spill could reasonably reach navigable waters of the United States or adjoining shorelines.

A facility that meets all three conditions must prepare and implement a written SPCC Plan. The plan documents the containment, inspection, and response measures the facility uses, and it must be available for EPA review. Many of the same drums that put a facility over the SPCC threshold also fall under workplace flammable liquid storage rules; see OSHA 1910.106 and NFPA 30 for the fire-code side of liquid storage.

The Secondary Containment Requirement

Secondary containment is the heart of the rule. Primary containment is the container itself, the drum, tank, or tote. Secondary containment is the backup barrier that holds the oil if the primary container leaks, overfills, or fails. Under 40 CFR 112.7(c), facilities must provide appropriate containment or diversionary structures to prevent a discharge, and the entire containment system, including walls and floor, must be capable of containing oil and constructed so that any discharge will not escape before cleanup occurs.

Two ideas govern whether a containment system passes:

• Sufficiently impervious. The containment surface has to hold the oil long enough for it to be cleaned up. A bare gravel pad or untreated soil drains oil into the ground and does not qualify. A molded polyethylene sump pallet, a coated concrete dike, or a lined berm does. The rule uses the phrase sufficiently impervious to contain oil, which the EPA reads as impervious for the period a spill would realistically sit before response.
• Adequate capacity. The containment volume must be large enough to hold the oil that could be released. For bulk storage containers, the rule sets a specific capacity floor, covered in the next section. For general areas such as a drum staging zone, the containment is sized to the most likely discharge.

A spill containment pallet is the most common way to give individual drums and totes compliant secondary containment. The drum sits on a grated deck, and the molded sump underneath catches any leak. Browse stocked units on the spill containment collection.

Sizing Containment: the Largest-Container Rule

For bulk storage containers, 40 CFR 112.8(c)(2) sets the sizing floor: the secondary containment must hold the capacity of the largest single container in the system, plus additional freeboard for precipitation when the containment is exposed to rain. That is the regulatory minimum, 100 percent of the largest container, and it is the largest single container, not the sum of every container in the area.

The common engineering convention adds a margin on top of that floor. Designers routinely size outdoor containment to 110 percent of the largest container so the extra 10 percent absorbs rainfall and provides freeboard before the sump fills. The 110 percent figure is a widely used design practice that satisfies the rule; it is not a separate number written into 40 CFR 112. Indoor containment that never sees rain may be sized closer to the 100 percent floor, subject to the facility's engineering judgment.

This is why a sump platform is rated by sump capacity rather than by the number of drums it holds. Under the sized-containment rule for bulk storage, 112.8(c)(2), the sump must hold the largest single container, so 55 gallon drums call for a sump of roughly 55 to 61 gallons, not 30. Smaller sumps, such as a 2 drum 30 gallon platform, are sized under the general containment provision, 112.7(c), to the most likely discharge in a staging area; whether that is acceptable depends on your SPCC plan and your authority having jurisdiction, so when in doubt size to the largest drum. For IBC totes, the 400 gallon sump IBC containment unit clears the 110 percent design target for a 330 gallon tote with freeboard to spare.

General vs Specific Containment

40 CFR 112.7 distinguishes between two kinds of containment, and a facility plan usually relies on both.

Plan Types and Self-Certification Tiers

The kind of SPCC Plan a facility needs depends on its size and spill history. The rule creates a lighter path for smaller operations through the qualified facility provisions in 40 CFR 112.6.

• Tier I qualified facility: aggregate aboveground oil storage of 10,000 US gallons or less, no single aboveground container larger than 5,000 gallons, and a clean recent spill record. The owner can self-certify a streamlined plan on the EPA template; no Professional Engineer review is required.
• Tier II qualified facility: aggregate aboveground oil storage of 10,000 US gallons or less with a clean spill record, but with one or more containers over 5,000 gallons. The owner can still self-certify, using a full plan rather than the template.
• PE-certified plan: facilities above 10,000 gallons aggregate, or that fail the spill-history test, need a full SPCC Plan reviewed and certified by a licensed Professional Engineer.

Across all tiers, the plan must be reviewed at least every five years and amended whenever the facility makes a change that materially affects its discharge potential, such as adding tanks or reconfiguring storage. The containment hardware itself, pallets and sumps, is the same regardless of tier; the tier determines who signs the paperwork.

Inspection and Recordkeeping

SPCC is not a one-time filing. The plan obligates the facility to inspect, test, and document on a recurring basis, and inspectors expect to see the records.

• Container inspections: aboveground containers are inspected regularly for leaks, corrosion, and signs of deterioration, on a schedule and with criteria set in the plan.
• Integrity testing: bulk storage containers are tested for integrity on a regular schedule under 112.8(c)(6), combining visual inspection with another technique appropriate to the container.
• Containment inspections: sump pallets, dikes, and curbed areas are checked so accumulated rainwater or product is removed and the containment volume stays available. A sump full of rain has no capacity left for a spill.
• Records retention: inspection and test records are kept with the SPCC Plan, typically for three years, and made available for EPA review.
• Personnel training: oil-handling staff are trained on the plan, spill procedures, and the equipment, with a designated person accountable for discharge prevention.

Keeping a sump pallet drained and free of debris is the single most common containment maintenance task, and an overdue drain is a routine inspection finding. The response equipment that backs up the containment, sorbents and ready-to-grab kits, is covered in the hazmat spill kit selection guide.

Frequently Asked Questions

Related Resources

• Secondary Containment Selection Guide (how to choose a pallet or sump)
• Spill Containment Pallets and Platforms (collection)
• Hazmat Spill Kit Selection Guide (spill response)
• OSHA 1910.106: Flammable Liquid Storage
• NFPA 30: Flammable and Combustible Liquids Code
• Eagle Manufacturing (the containment brand we stock)
• Safety & Compliance Standards (index)