The Environmental Protect Agency’s (EPA) Spill Prevention Control and Countermeasures (SPCC) Rule aims to prevent illegal discharges of oil into navigable U.S. waters and adjoining shorelines. The EPA acknowledges that primary containers can fail and requires companies that store high amounts of oil to have secondary containment.
The SPCC rule requires facility owners or operators with more than 1,320 gallons of aboveground oil storage capacity or 42,000 gallons of underground oil storage capacity to have a written plan that addresses how the facility will prevent oil spills to navigable waters and adjoining shorelines. Regulations also require facilities to be prepared for, and have the ability to respond to oil discharges, if the processes and/or devices put into place fail.
Violations of SPCC secondary containment requirements have historically resulted in companies being fined thousands of dollars.
The EPA does not specify particular methods or devices that must be used or applied to prevent discharges, which gives facility managers the flexibility to determine the best way for their facility to comply.
The methods listed in a facility’s plan should be in accordance with accepted “good engineering practices,” and sometimes must be certified by a Professional Engineer (PE).
Secondary Containment
Secondary containment for bulk containers is a required element of SPCC. The EPA’s SPCC Guidance for Regional Inspectors states that “secondary containment is required for all facilities with bulk storage containers, large or small, manned or unmanned, and for facilities with bulk storage containers that also have oil-filled equipment.”
According to the EPA, a bulk container is “any container (with a capacity of 55 gallons or more) storing oil at a facility. Bulk oil storage containers may include, but are not limited to tanks, containers, drums and mobile or portable totes.”
Oil-filled equipment — such as transformers, hydraulic systems, lubricating systems, gear boxes, machining coolant systems, heat transfer systems, circuit breakers and electrical switches — must also have secondary containment.
Active Versus Passive
According to the EPA, secondary containment can be active or passive as long as discharge cannot escape the device [40 CFR 112.7(c)].
Active secondary containment is when an employee personally contains a spill. Active secondary containment includes:
- Deploying drain covers before a spill happens
- Deploying drain covers after a spill has occurred, but before the spill reaches a drain
- Using a spill kit in the event of an oil discharge
- Having a spill response team in the event of an oil discharge
- Closing a gate valve prior to a discharge
Active secondary containment may not be appropriate or possible for all situations due to lack of resources and staff. Unlike active secondary containment, passive secondary containment does not require deployment or the action of an employee or employees to contain a spill.
Passive secondary containment includes:
- Placing containment pallets or decks under drums and other containers
- Surrounding machines and containers with berms
- Erecting retaining walls around machines and containers
- Placing drip trays under leaky machines and containers
General and Specific Containment
The EPA specifies two types of secondary containment requirements under the SPCC rule: general and specific.
The general secondary containment requirements are “intended to address the most likely oil discharge from bulk storage containers; mobile/portable containers; production tank battery treatment, and separation installations; a particular piece of oil-filled operational or process equipment; (non-rack) transfer activity; or piping in accordance with good engineering practice,” according to the EPA’s SPCC Guidance for Regional Inspectors.
There is no specified volume that needs to be contained under the general requirements because they address the “most likely oil discharge” and encompass containers, processes and oil-filled equipment.
According to the EPA’s SPCC Guidance for Regional Inspectors, the specific secondary containment requirements are “intended to address a major container failure… these specific provisions explicitly provide requirements for sizing, design and freeboard that need to be addressed in the SPCC Plan.”
Specific secondary containment requirements apply to the following:
- Bulk storage containers
- Loading/unloading racks
- Mobile or portable bulk storage containers
- Production facility bulk storage containers, including tank batteries, separation, and treating vessels/equipment
Unfortunately, the SPCC rule does not specifically define the term “freeboard,” nor does it describe how to calculate the volume for secondary containment. A PE can help determine if a containment system has sufficient volume. Two generally accepted methods for determining sufficient freeboard for a containment device include:
- Using historical data from the past 25 years to calculate the volume based on the worst 24-hour storm event in the area
- Ensuring that the sump is capable of holding 110% of the volume stored
Containment Considerations
Facility managers should consider the following points to determine what type or types of secondary containment are appropriate for their various areas and/or processes:
- What are the potential sources of failure that may cause a discharge?
- How quickly can oil be discharged?
- How will discharges be detected?
- How will personnel react to a discharge?
Whether containment is active or passive or general or specific, the goal is always the same: preventing oil from being discharged into navigable waters or adjoining shorelines. Having the ability to contain spills at or near their source helps minimize the potential for discharge.
8 Comments
Scott Olsonsays:
02/14/2017 at 10:28 amI have a 1000 gallon fuel tank on a work location. It is a double walled tank. Is the double wall not considered secondary containment? If so, what regulation explains this?
Karensays:
02/16/2017 at 8:48 amHi Scott, check out this memorandum from the EPA discussing this topic: https://www.epa.gov/sites/production/files/2014-04/documents/h_2002_memo_horinko.pdf
-Karen
Jeffsays:
02/24/2017 at 7:38 amDo these regulations apply to other chemicals such as caustic soaps and chlorine based sanitizing chemicals? I know this article deals with oil.
Karensays:
03/03/2017 at 5:43 pmHi Jeff,
The SPCC rules only apply to oil and oil products. But that doesn’t necessarily mean that you’re out of the water. Caustic soaps and chlorine-based sanitizing chemicals may be considered hazardous and may be covered under other EPA and OSHA regulations, depending upon the specific hazards of each of the chemicals as well as the quantities that you have stored at your facility.
Providing secondary containment for these chemicals would be considered a best management practice (BMP) to help meet the spill prevention planning requirements of regulations such as:
Even if none of these regulations apply to your facility, many facilities provide secondary containment for all chemicals stored onsite as a general BMP to promote safety and housekeeping efforts. It is much easier to clean up a spill that has been contained, and a spill that has been contained is less likely to create a slip and fall hazard.
Hope this info helps!
Best,
Karen
DJsays:
10/18/2017 at 12:01 pmI have (10) 275 gallon totes of oil stored above ground, how tall of a containment wall do I need around the perimeter?
Karensays:
01/02/2018 at 3:14 pmHi DJ,
Totes come in different shapes. The most common are round and square. They can also be arranged in an endless number of ways. To keep things simple for this example, I’ve chosen to use 4’ square totes, spaced with 3’ of aisle space around each tote.
Step 1: Calculate 10% of the total volume of all containers that will be stored in the area and compare it with the total volume of a single container to determine which is larger. In this scenario, the answer is 275 gallons either way.
Largest container: 275 gallons
10% of total volume: 10 containers x 275 gallons per container x 10% = 275 gallons
Step 2: Determine if any additional containment capacity is needed to contain “run on” (rain and/or snowmelt). If the containment area will be outdoors and uncovered, EPA requires that additional sump capacity be added to allow for rain or snowmelt in addition to the volume of liquid that could spill. This volume is most commonly determined by one of the two methods:
At the federal level, neither of these two methods is mandated, but some states require one of these methods
Step 3: Determine the minimum square footage for the containment area
For this example, I’m using ten totes that are each 4’ square, arranged in two rows of five totes, allowing a 3’ aisle/walkway around each tote for inspections and access. In this configuration, the minimum length would be 38’ and the minimum width would be 17’, for a total of 646 square feet of space.
From this figure, the volume displaced by each tote needs to be subtracted.
Now, remember that we used a cubic foot for this calculation. That means that the wall/berm around the perimeter would be 1’ high. If you choose to put a 6” berm around the perimeter, you’d cut your volume in half (1817.64 gallons) and if you chose a 4” berm, your containment volume would be 1210.55 gallons.
Any of these volumes is well above what would be required for the ten totes, given the square footage listed in this example.
You do have a lot of options when creating a containment area, and it may help to explore different options to see which works best. For example, if the totes are stackable, you could reduce the square footage requirements and still reach your containment needs without having to put in a high berm around the perimeter. Using our previous example, if you stacked five of the totes on top of the other five and kept 3’ of aisle space between each one, you’d only need a 38 x 10 perimeter. This would be 380 square feet of space, and even with a 4” berm you’d still have 748 gallons of containment, which is also well above what is needed. The bottom line is that for 275 gallons of containment, the wall won’t need to be especially tall.
Please let us know if you have any other containment questions!
Best,
Karen
Ahmed uzairsays:
11/10/2017 at 1:19 pmHi
Kindly update as its mention the margin for chemical drums are 10% of its volume. If the tank is of 2000 liters or above then what would be the height of the containment with the provision of 10% increased area of its total volume.
Brittanysays:
11/13/2017 at 10:16 amThere are a few regulations that may apply to this situation. The EPA requires secondary containment for drums and other containers, including tanks, that are storing hazardous waste. The secondary containment system must be capable of containing either 100% of the largest container in the system or 10% of the total volume of all containers stored in the system, whichever volume is greater.
If the only container in your secondary containment area is the 2,000 liter tank, the containment system would need to be able to contain all 2,000 liters, not just 10% of that.
If the tank contains an oil product, and your facility stores 5,000 liters or more in aboveground containers and/or tanks, SPCC rules would apply. This regulation also requires secondary containment. Because secondary containment systems and devices are designed to prevent spills from leaving the containment area, you should have a secondary containment system that is capable of containing your worst case scenario spill.
If a leak or spill from the tank could enter a waterbody, Stormwater rules would apply. Providing a secondary containment system that is capable of holding the entire contents from a spilled tank would be a best management practice that would prevent a release from entering a waterbody.
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