Introduction To Secondary Containment Requirements:
Secondary containment requirements are addressed by the Environmental Protection Agency (EPA) through the Resource Conservation and Recovery Act (RCRA) contained in title 40 of the Code of Federal Regulations (CFR) part 264, the 2006 Uniform Fire Code (UFC) in standard 22.214.171.124.3 and in the 2012 International Fire Code (IFC) in 5004.2.
The EPA refers to the need for secondary containment in two different areas: Subpart I, Use and Management of Containers (40 CFR 264.175), which covers portable storage containers, such as 55-gallon drums, for hazardous waste, and the second in Subpart J, Tank Systems (40 CFR 264.193), which covers large stationary containers, such as tank systems, for hazardous waste. Facilities that store hazardous materials may also be required to meet either the UFC or IFC depending on what the locality has adopted.
Throughout this document, the federal secondary containment requirements from the EPA will be listed along with the UFC and IFC standards. If there is any question regarding compliance, consult with a local fire marshal for more information.
EPA: Portable Containers
The EPA does not bring secondary containment requirements into context when addressing portable containers. Instead, they refer only to containment under 40 CFR part 264.175(b). It says that a containment system must be designed and operated as follows:
- A base must underlie the containers which is free of cracks or gaps and is sufficiently impervious to contain leaks, spills, and accumulated precipitation until the collected material is detected and removed.
- The base must be sloped or the containment system must be otherwise designed and operated to drain and remove liquids resulting from leaks, spills or precipitation unless the containers are elevated or are otherwise protected from contact with accumulated liquids.
- The containment system must have sufficient capacity to contain 10% of the volume of containers or the volume of the largest container, whichever is greater. Containers that do not contain free liquids need not be considered in this determination.
- Run-on into the containment system must be prevented unless the collection system has sufficient excess capacity in addition to that required in paragraph (b)(3) of this section to contain any run-on which might enter the system.
- Spilled or leaked waste and accumulated precipitation must be removed from the sump or collection area in as timely a manner as is necessary to prevent overflow of the collection system.
Under 40 CFR part 264.175(c), the EPA also addresses storage areas that store containers holding only wastes that do not contain free liquids and sets the following provisions for the storage areas:
- The storage area is sloped or is otherwise designed and operated to drain and remove liquid resulting from precipitation, or
- The containers are elevated or are otherwise protected from contact with accumulated liquid.
There are certain wastes for which a storage area alone will not suffice. These waste streams are listed under 40 CFR part 264.175(d) and require a containment system in addition to the storage area.
EPA: Tank Systems
The EPA specifies under 40 CFR part 264.193(b) that secondary containment systems are required to prevent any migration of wastes to soil, groundwater, or surface water during the use of the tank system. Within this citation, minimum requirements of how the system must be constructed are listed in detail in paragraph (c):
- Constructed of or lined with materials that are compatible with the wastes to be placed in the tank system and must have sufficient strength and thickness to prevent failure owing to pressure gradients (including static head and external hydrological forces), physical contact with the waste to which it is exposed, climatic conditions and the stress of daily operation (including stresses from nearby vehicular traffic).
- Placed on a foundation or base capable of providing support to the secondary containment system, resistance to pressure gradients above and below the system and capable of preventing failure due to settlement, compression, or uplift.
- Provided with a leak-detection system that is designed and operated so that it will detect the failure of either the primary or secondary containment structure or the presence of any release of hazardous waste or accumulated liquid in the secondary containment system within 24 hours or at the earliest practicable time if the owner or operator can demonstrate to the regional administrator that existing detection technologies or site conditions will not allow detection of a release within 24 hours.
- Sloped or otherwise designed or operated to drain and remove liquids resulting from leaks, spills, or precipitation. Spilled or leaked waste and accumulated precipitation must be removed from the secondary containment system within 24 hours, or in as timely a manner as possible to prevent harm to human health and the environment if the owner or operator can demonstrate to the regional administrator that removal of the released waste or accumulated precipitation cannot be accomplished within 24 hours.
Along with the above requirements, a provision has been made that requires that one or more of the following devices also be implemented:
- A liner (external to the tank)
- A vault
- A double-walled tank
- An equivalent device as approved by the regional administrator
These four devices need to meet rather stringent specifications. As an example, an external liner must be:
- Designed or operated to contain 100% of the capacity of the largest tank within its boundary.
- Designed or operated to prevent run-on or infiltration of precipitation into the secondary containment system unless the collection system has sufficient excess capacity to contain run-on or infiltration. Such additional capacity must be sufficient to contain precipitation from a 25-year, 24-hour rainfall event.
- Free of cracks or gaps.
- Designed and installed to surround the tank completely and to cover all surroundings likely to come into contact with the waste if the waste is released from the tank(s) (i.e., capable of preventing lateral as well as vertical migration of the waste).
UFC/IFC: Secondary Containment
Both the UFC and IFC cover secondary containment requirement standards for facilities that store hazardous materials and not just hazardous wastes that are the focus of the EPA standards. The UFC and IFC are very similar, except the IFC goes into more detail in regards to the outdoor design of secondary containment, monitoring and drainage systems. Both state that buildings or portions thereof, used for any of the following shall be provided with secondary containment to prevent the flow of liquids to adjoining areas:
- Storage of liquids (including corrosive, flammable, toxic and combustible) where the capacity of an individual vessel exceeds 55 gallons (208L) or the aggregate capacity of multiple vessels exceeds 1000 gallons (3785L)
- Storage of solids where the capacity of an individual vessel exceeds 550 lb. (248 kg) or the aggregate capacity of multiple vessels exceeds 10,000 lb. (4524 kg)
UFC/IFC: Indoor Storage Areas
The UFC and IFC differ from the EPA because it states that the secondary containment for indoor storage areas must contain a spill from the largest vessel plus the flow volume of fire protection water calculated to discharge from the fire-extinguishing system over the area in which the storage is located for a period of 20 minutes. It also mentions that incompatible materials shall be separated from each other in secondary containment systems.
IFC: Outdoor Storage Areas
The IFC mentions outdoor secondary storage areas that follow the EPA tank system design stating that they shall be designed to contain a spill from the largest individual vessel. If the area is open to rainfall, it shall be capable of containing the volume of a 24-hour rainfall as determined by a 25-year storm. The UFC does not mention outdoor storage areas.
Both the UFC and IFC state that secondary containment shall be achieved by means of drainage control to prevent the discharge of liquids to public waterways, public sewers, or adjoining properties. The building room or area shall contain or drain the hazardous materials and fire protection water through the use of one of the following methods:
- Liquid-tight, sloped or recessed floors in indoor locations or similar areas in outdoor locations
- Liquid-tight floors in indoor locations or similar areas in outdoor locations with liquid-tight, raised or recessed sills or dikes
- Sumps and collection systems
- Drainage systems leading to an approved location
The IFC adds to this, stating the slope of floors shall not be less than 1%, drains for indoor storage areas shall be sized to carry the volume of the fire protection water as determined and drains for outdoor storage areas shall be sized to carry the volume of the fire flow and the volume of a 24-hour rainfall as determined by a 25-year storm.
The UFC and IFC state that an approved method shall be provided to detect hazardous materials in the secondary containment system, but the IFC further mentions that a visual inspection is allowable and that detection for water in secondary containment systems must be provided if subject to water intrusion. Monitoring devices shall be connected to an approved visual or audible alarm.
Choosing a Containment System
When selecting a containment system for an application, many issues need to be considered. A list of issues and some things to contemplate are listed below.
- Is the system chemically compatible with the products being stored?
- Containment system sumps are primarily constructed of one or two materials: high-density polyethylene and steel.
- Polyethylene skids usually have material choices for grids or platforms. The choice of material depends on chemical resistance as well as the dispose-ability of the product. Examples include:
- Wood platforms: Once contaminated, they are disposed of according to local regulations.
- Fiberglass grids: Compatible with a wide variety of chemicals, but not suitable for corrosive materials.
- Polyethylene grids: Compatible with a wide variety of chemicals including many corrosive materials.
- How will the system be monitored and cleaned?
- Most units have drains. If they don’t, usually a spill cleanup kit will be adequate to clean up the internal sump area of the system.
- What volume and weight of the containers will be stored?
- According to federal codes, a containment system must have a sufficient capacity to contain 10% of the volume of the containers or the volume of the largest container, whichever is greater. Some states may have more stringent restrictions and you should contact your local fire marshal for your local requirement.
- Containment systems are commonly rated with a static weight capacity. This is a weight in a stationary mode.
- How often will the containment system be moved? How will it be moved?
- Portable containment units are intended to be moved without containers on them. This is the safest mode of transport. The containers can be replaced once the containment system has reached its destination.
- Most portable containment systems are constructed with fork pockets. These are designed to accept and be moved by forklifts.
- How will the containers be loaded onto the system?
- Ramps that accommodate containment systems are the easiest way to load a system. Low-profile containment systems have also been developed to address the loading issues.
- How many containers will be loaded on the system?
- Portable containment systems range from accommodating four 5-gallon pails to one 55-gallon drum to whole-room containment systems for drums. Make sure when dealing with flammable products and the larger containment systems that your local fire codes are met. There are restrictions for quantities of flammable products that can be stored in one area depending on the class of the flammable product.
- Are any of the products being stored considered flammable?
- Special provisions need to be taken into accounts, such as grounding and bonding and the number of flammable products being stored in one area. Check into local codes for these specifications.
- What are the state and local codes for secondary containment in your area?
- A listing of the regional EPA offices can be found on EPA website. Phone numbers of divisions that deal with secondary containment are listed. The regional office can refer to state EPA agencies that can explain state codes. Another source for secondary containment requirements is your local fire marshal.
The following are some related terms as defined by the EPA and UFC.
Container: Any portable device, in which a material is stored, transported, treated, disposed of or otherwise handled. Any vessel of 60 gallons (227L) or less capacity used for transporting or storing hazardous materials.
Containment building: A hazardous waste management unit that is used to store or treat hazardous waste under the provisions of subpart DD of parts 264 or 265 of title 40.
Leak-detection system: A system capable of detecting the failure of either the primary or secondary containment structure or the presence of a release of hazardous waste or accumulated liquid in the secondary containment structure. Such a system must employ operational controls (e.g., daily visual inspections for releases into the secondary containment system of above-ground tanks) or consist of an interstitial monitoring device designed to detect continuously and automatically the failure of the primary or secondary containment structure of the presence of a release of hazardous waste into the secondary containment structure.
Liner: A continuous layer of natural or man-made materials, beneath or on the sides of a surface impoundment, landfill, or landfill cell, which restricts the downward or lateral escape of hazardous waste, hazardous waste constituents, or leachate.
Portable tank: Any packaging over 60 gallons (227L) capacity and designed primarily to be loaded into, on or temporarily attached to a transport vehicle or ship and equipped with skids, mountings or accessories to facilitate handling of the tank by mechanical means. It does not include any cylinder having less than a 1000 lb. water capacity, cargo tank, tank car tank, or trailers carrying cylinders of over 1000 lb. water capacity.
Primary containment: The first level of containment, consisting of the inside portion of that container which comes into immediate contact on its inner surface with the material being contained.
Secondary containment: That level of containment that is external to and separate from the primary containment.
Stationary tank: Packaging designed primarily for stationary installations not intended for loading, unloading, or attachment to a transport vehicle as part of its normal operation in the process of use. It does not include cylinders having less than 1000 lb. water capacity.
Sump: Any pit or reservoir that meets the definition of a tank and those troughs/trenches connected to it that serve to collect hazardous waste for transport to hazardous waste storage, treatment or disposal facilities; except that as used in the landfill, surface impoundment and waste pile rules, sump: means any lined pit or reservoir that serves to collect liquids drained from a leachate collection and removal system or leak detection system for subsequent removal from the system.