The invention relates to a portable, foldable containment device for hazardous chemicals such as petrochemicals, and the like, and the prevention of environmental contamination by the chemicals. For example, environmental contamination is the long-term result of point source spills in the transfer of petrochemicals and the like from one container to another. In particular, the problem of loading and off-loading petrochemicals and preventing environmental contamination is a problem to which considerable attention need be given because in the transfer of the chemicals, spills can occur and it is necessary to prevent the spill from absorption in the soil.
In the past, temporary, disposable, or stationary containments have been provided in which a plastic membrane or fabric which contains the chemical is supported by air inflatable walls or foam for containing the chemical. U.S. Pat. No. 4,671,024 discloses a disposable drip pan for use under a vehicle which contains dirt or other matter and to prevent the same from soiling or contaminating a floor surface at a fixed site. Air inflated sleeves or radially compressible pipe tubing form a ridge which surrounds a floor of the drip pan to contain material falling off the vehicle. While a vehicle may be driven over the ridge, the ridge is not sufficient for containing liquid spills, such as agricultural chemicals, in large volumes, nor is it fastened to the floor to prevent dislocation by prop wash from aircraft. The corners are not designed to withstand impact from vehicle traffic. Similar temporary containment systems are known which may be folded, assembled, inflated, and transported having a rubberized fabric which withstands rough treatment and a broad range of chemicals. However, again, the support tubes for the side walls are inflatable with air are susceptible to puncture and are separate pieces that require assembly. With the side walls inflated, considerable risk is involved when driving a vehicle on or off the containment, and the walls must be removed to allow vehicle traffic. To deflate the walls permits liquid to escape the containment.
Additionally, U.S. Pat. No. 5,090,588 discloses a portable containment for chemicals that is comprised of resilient braces. While providing good egress into and out of the containment, the resilient nature of this portable containment limits the spill-retention capacity by restricting the maximum height of the containment walls. The resilient nature of the walls prohibit the containment unit from effectively containing a voluminous spill. In the event of a voluminous spill, the wall tends to bow concentrating a disproportional amount of pressure upon a small area of the containment and hence increasing the risk of rupturing. Additionally, the interior bracing straps are designed to allow a resiliently braced wall to be driven over by a vehicle, and would not support a much higher wall, thus requiring a rigid brace.
Accordingly, an object of the invention is to provide a portable containment unit having a relatively high wall for containing voluminous spills; and which is economical, portable, and easy to transport and deploy, and which may be reused.
Another object of the invention is to provide a containment having a rigidly enforced side wall for containing a large spill of hazardous chemicals and the like which is truly portable in that it may be folded, transported, and reused at different sites without disassembly or reassembly being required.
Another object of the invention is to provide a foldable portable containment unit for the prevention of ground spills which is highly durable and can withstand vehicle traffic onto and off of the unit.
Another object of the invention is to provide a portable containment unit which is portable, requires no assembly at the site, can withstand vehicle traffic over the walls of the containment unit, and can tolerate toxic chemicals such as pesticide solutions.