Manufacturing facilities commonly store various chemical substances in aboveground storage tanks. Most facilities ensure chemical storage areas are equipped with proper secondary containment measures to prevent releases of hazardous substances from entering the environment. In many cases, secondary containment measures consist of sealed concrete structures including flooring and curbing. However, it is not uncommon for tanks to be located within earthen containment areas, in which soils are compacted or clay-lined beneath the tanks and earthen berms are built around the tanks to contain releases.
Although earthen secondary containment may seem rudimentary, EPA guidance suggests releases of hazardous substances within properly constructed earthen containment units are accorded the same regulatory status as those within a concrete structure. Thus, even when a reportable quantity of hazardous substances is released within an earthen containment area, facilities may not be required to report the release to the National Response Center (NRC) if the release is fully contained.
Upon gaining knowledge of the release of a reportable quantity of a hazardous substance to the environment, the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) requires a person in charge at a facility to immediately report the release to the NRC. A “person in charge” is an employee who has responsibility for environmental issues at the facility. This does not include every person who might have knowledge. Furthermore, notification by someone other than a person in charge does not satisfy the CERCLA reporting obligation. For instance, an administrative assistant or delivery driver who arrives at a facility early one morning and discovers a release would not qualify as a “person in charge” for purposes of reporting the release to the NRC.
“Knowledge” is interpreted by EPA to include actual knowledge or constructive knowledge, with constructive knowledge being a level of awareness that would lead a reasonable person to investigate further. “Immediate” reporting is interpreted by EPA and the courts to mean within 15 minutes of the person in charge gaining knowledge of the release.
Finally, to be a reportable release, the hazardous substance must have been released “to the environment.” CERLCA defines “environment” to include “[t]he navigable waters, the waters of the contiguous zone, and the ocean waters . . . of the United States . . . and any other surface water, ground water, drinking water supply, land surface or subsurface strata, or ambient air . . .” At first glance, an earthen containment area seems to qualify as a “land surface,” triggering the CERLCA reporting obligation in the event of a release. However, EPA guidance suggests that, when an earthen containment structure is designed, constructed, and maintained to contain a hazardous substance, and in fact does contain the substance when released, the release is not to the environment. EPA specifically lists several examples of secondary containment that are not considered “the environment.” These include concrete pads with provisions to catch any runoff, open tank containment units, clay-lined or synthetically lined disposal facilities, and clay ditches and dikes.
In practice, EPA will consider facts such as the depth of the clay-liner, the volume of constructed soil, and the level of compaction when determining whether an earthen containment structure is “the environment.” However, when properly constructed to prevent infiltration of released substances below compacted soils and beyond earthen berms, such a structure may be adequate for a facility to avoid reporting of a release.
Facilities should evaluate the integrity of all secondary containment structures, earthen or otherwise, to ensure they will properly contain any release of hazardous substances and prevent the release from entering the environment. Facilities should also carefully consider internal protocols for release reporting to ensure only required reports are made.