Introduction

Different methods of secondary containment are fitting depending on the circumstance. This Fact File gives a detailed look at Spill Prevention, Control, and Countermeasure (SPCC) secondary containment. Presented here is information on general versus specific provisions for secondary containment and examples of secondary containment methods.

Applicable laws and regulations

40 CFR 110 — Discharge of Oil

40 CFR 112 — Oil Pollution Prevention

Background

The SPCC rule aims to prevent discharges of oil into navigable waters of the United States and attached shorelines. One of the main ways the rule achieves this goal is by necessitating secondary containment. A secondary containment system offers a powerful defensive tool in the event of a failure of the primary containment, such as a bulk storage container, a mobile or portable container, piping, or oil-filled equipment. The system delivers temporary containment of discharged oil until suitable activities are taken to decrease the source of the discharge and remove oil from parts where it has accrued to prevent it from reaching navigable waters or adjoining shorelines.

Examples of secondary containment methods

Examples of secondary containment methods includes the following:

1. Dikes, berms, or retaining walls adequately impervious to hold oil: These are permanent engineered barriers, like raised earth embankments or concrete containment walls, designed to hold oil. They are typically used in areas probable for major discharges, like single or multiple aboveground storage tanks and certain piping. Temporary dikes and berms can be constructed after a discharge is revealed as an active containment measure so long as they can be executed in time to avert the spilled oil from reaching waters.
2. Curbing: This usually consists of a permanent reinforced concrete or an asphalt apron surrounded by a concrete curb. It can also be of a uniform, rectangular cross-section or combined with mountable curb sections to permit access to loading/unloading vehicles and materials handling equipment. Curbing can be used where only minor spills are expected and used to direct spills to drains or catchment areas. Temporary curbing may be constructed after a discharge is revealed as an active containment measure so long as it can be executed in time to avert the spilled oil from reaching surface waters.
3. Culverting, gutters, or other drainage systems: These are kinds of permanent drainage systems intended to direct spills to remote containment or treatment areas. Ideal for situations where spill containment structures cannot or should not be situated directly adjacent to the possible spill source.
4. Weirs: Dam-like structures with a notch through which oil may flow to be gathered. Typically used in combination with skimmers to remove oil from the surface of water.
5. Booms: Form a constant barrier placed as a cautionary measure to contain/collect oil. Typically associated with an oil spill contingency or facility response plan to address oil spills that have reached surface waters. Beach booms are meant for shallow or tidal areas. Sorbent-filled booms can be used for land-based spills.
6. Barriers: Spill mats, storm drain covers, and dams used to block or prevent the flow of oil. Temporary barriers may be put in place prior to a discharge or after a discharge is discovered. These are all considered effective active containment measures as long as they can be implemented in time to avert the spilled oil from reaching navigable waters and adjoining shorelines.
7. Spill diversion ponds and retention ponds: Intended for long-term or permanent containment of storm water, but also capable of capturing and holding oil or runoff and avoiding it from entering surface water bodies. Temporary spill diversion ponds and retention ponds may be built after a discharge is revealed as an active containment measure as long as they can be implemented in time to avert the spilled oil from reaching navigable waters and adjoining shorelines.
8. Sorbent materials: Insoluble materials or mixtures of materials (packaged in forms like spill pads, pillows, socks, and mats) used to recover liquids through absorption, adsorption, or both. Materials include clay, vermiculite, diatomaceous earth, and artificial resources. Used to isolate and hold small drips or leaks until the source of the leak is fixed. They are often used with material handling equipment, such as valves and pumps. Also used as an active containment measure to hold and collect small-volume discharges before they reach waterways.
9. Drip pans: Used to isolate and contain small drips or leaks until the source of the leak is fixed. Drip pans are usually used with product dispensing containers (drums), when uncoupling hoses during bulk transfer operations, and for pumps, valves, and fittings.
10. Sumps and collection systems: A permanent pit or reservoir and its related troughs/trenches that gather oil.

General vs. specific secondary containment requirements

There are two categories of secondary containment requirements:

• A general provision addresses the likelihood for oil discharges from all regulated parts of a facility. The containment method, design, and capacity are determined by good engineering practice to hold the most likely discharge of oil until cleanup happens. In making a determination for general secondary containment, only the typical failure mode needs to be considered.
• Specific provisions address the likelihood of oil discharges from areas of a facility where oil is kept or handled. The containment design, sizing, and freeboard requirements are detailed by the SPCC rule to address a large container failure.

Key to remember

In some circumstances, permanent containment structures, like dikes, may not be possible. The general secondary containment provision allows for the use of both active and passive containment measures to prevent a discharge to waterways. With active containment, the containment measure involves a certain action by facility personnel before or after the discharge occurs. With passive containment, the containment measure stays in place irrespective of the facility operations and does not require an action by facility personnel.

Related definitions

Discharge means any spilling, leaking, pumping, pouring, emitting, emptying, or dumping of oil.

Oil means oil of any type or in any form, including, but not limited to: fats, oils, or greases of animal, fish, or marine mammal origin; vegetable oils, including oils from seeds, nuts, fruits, or kernels; and, other oils and greases, including petroleum, fuel oil, sludge, synthetic oils, mineral oils, oil refuse, or oil mixed with wastes other than dredged spoil.

Real world example

Oil spills harm citizen health, impact drinking water, destroy natural resources, and disturb the economy. During storage, transport, or from energy exploration and production actions, oil and oil-based products are sometimes spilled onto land or into waterways. When this happens, every effort must be made to prevent further damage from oil spills and to clean them up punctually once they happen. The costs related to spill prevention are regularly much less than the costs related to spill clean-up, fines, and other civil charges. A petroleum company with a crude oil tank battery in North Dakota agreed to pay $50,000 for SPCC violations. Among the issues cited, they had an insufficient facility-wide SPCC Plan, insufficient secondary containment measures for the storage tanks, and various other deficiencies in tank batteries. Aim to avoid being like that company and protect your facility and nearby waterways from potential discharges with proper secondary containment.