Containment storage apparatus

A secondary containment apparatus for use in combination with primary containers for hazardous wastes such as drums or large barrels, comprising a generally rectangular base member and two generally rectangular lid members of a size sufficient to enclose one or more primary containers. The lid members are moveable only laterally in relation to the base member, the lateral movement allowing access to the drums contained within. The lid members have interlocking means to form a releasable closure, and have engagement means for attachment to the base member. The base member is impermeable to liquids, and is preferably composed of translucent plastic for visual inspection.

BACKGROUND OF THE INVENTION 
This invention relates generally to the field of secondary containment 
storage systems used to store primary containers containing hazardous 
wastes. More particularly the invention relates to a transportable 
apparatus able to completely enclose hazardous materials in a structure 
which prevents accidental spillage or loss of the hazardous waste in the 
case of damage to the primary containers. 
Our modern society produces waste materials which can harm the environment 
if not stored, transported or disposed of in a safe manner. Numerous 
regulations by various governmental agencies set forth requirements which 
must be adhered to in the handling of such hazardous materials. Even a 
small volume generator of hazardous materials must follow guidelines for 
handling such materials safely. The danger of harm is so significant that 
numerous regulations are directed toward secondary containment units which 
will entrap any spillage or loss from the primary storage containers, such 
as large drums, before the hazardous waste can pollute the outside 
environment. 
Such secondary containment units are generally known in the art. For 
example, Olmsted in U.S. Pat. No. 4,361,232 teaches a protective container 
for use with large drums. The container comprises a solid, rectangular pan 
with side walls and a removable lid to fit over the pan. The device is 
constructed so as to rest on a typical wooden pallet and is designed to 
contain a number of large drums filled with hazardous liquid waste. The 
lid has side walls which overlap the walls of the pan when the lid is 
resting on the drums. The device is very simple in nature, and it is this 
simplicity which creates problems and inadequacies. The device requires 
that the lid be completely removed for access to the individual drums, 
which is not desirable for situations where the drums are being filled in 
small increments over a period of time, as in practice the user tends to 
fail to replace the lid after each use. Additionally, the device requires 
a secondary component, the conventional pallet, for transport of the unit. 
The device of Olmsted also requires a liquid level sensor to create an 
alarm should there be a loss of liquid from the primary storage units. 
Additionally, the seal between lid and pan is not secure against overflow 
or environmental forces, requiring a gasket to increase containment 
capability. 
It is an object of the invention to provide a secondary containment storage 
apparatus capable of enclosing one or more large drums containing 
hazardous waste materials, where the apparatus will retain without loss 
hazardous waste stored in the drums, should leakage occur. 
It is a further object to provide such an apparatus having a sliding, 
interlocking lid such that removal of the lid from the main base member is 
not required for access to the drums, yet the two lid sections when closed 
will prevent ingress of rain, snow, etc. into the unit. 
It is a further object to provide such an apparatus where the seal between 
lid and main body prevents ingress of rain, snow, etc., and is capable of 
withstanding relatively large load forces without separation. 
It is a further object to provide such an apparatus where the base member 
is designed to allow movement of the unit by conventional forklifts or 
pallet jacks. 
It is a further object to provide such an apparatus with translucent side 
walls for visual indication of fluid level. 
It is a further object to provide such an apparatus where the base members 
of plural units are nestable for storage and transport, with the lid 
sections fitting in the interior of the base members. 
BRIEF SUMMARY OF THE INVENTION 
The invention is a secondary containment apparatus for use in combination 
with primary waste containers, such as large drums or barrels. The 
apparatus comprises a base member and two lid members which combine to 
create a closed container around one or more drums. The overall 
configuration of the unit is rectangular. The base member comprises a 
bottom, side walls and end walls, with an open top. Preferably the walls 
and ends are angled slightly outward. The lid members each comprise a top, 
end wall and side walls, with the side walls and end walls also angling 
slightly outward. The lid members have engagement means to attach the lid 
members to the base member, such that the lid members may slide laterally 
in relation to the base member. The lid members further comprise 
interlocking means to form a retaining seal when the lid members are 
connected. When the lid members are engaged on the base member and 
interlocked with each other, the unit completely encloses the primary 
storage drums in a closed system. 
The base member preferably comprises a rail member which provides a track 
for the lateral movement of the lid members. The engagement means of the 
lid members attach to this rail member. The interlocking means of the lid 
members is preferably comprised of interfitting lips which easily snap 
closed and release. Leg members are attached to the bottom of the base 
member to allow use of a forklift or pallet jack to move the unit. The 
apparatus is preferably constructed of a translucent plastic material.

DETAILED DESCRIPTION OF THE INVENTION 
The invention will be described, with the accompanying drawings, in the 
structural configuration for containment of two large drums. It is to be 
understood that the invention also encompasses structural configurations 
sized for containment of any number of drums, including the circumstance 
of a single drum. Such configurations will differ only in overall 
dimensions, the elements and components of the invention remaining the 
same. 
With reference to FIGS. 1 and 2, the overall configuration of the invention 
is shown. The apparatus comprises a base member 10 and two lid members 20. 
The general shape of the apparatus is a rectangular container. Base member 
10 comprises a bottom 11, two side walls 12 and two end walls 13. Bottom 
11 is substantially rectangular with side walls 12 and end walls 13 
substantially upright. Bottom 11 is relatively planar to support the 
drums, but may be constructed with ridges or other raised areas. 
Furthermore, a drain may be incorporated in bottom 11, which can also be 
sloped, to facilitate drainage. It is preferable that side walls 12 and 
end walls 13 angle slightly outward, such that the open top of base member 
10 is larger than bottom 11. This allows plural base members 10 to be 
nested one inside the next for purposes of storage and transportation. 
Extending below bottom 11 are a number of legs 14 to support the base 
member 10 above the floor surface. Legs 14 are of sufficient height and 
separation to allow room for insertion of the arms of a forklift or pallet 
jack for transport of the unit. Preferably, legs 14 are circular to 
deflect the forklift arms without damage should the operator strike one of 
the legs 14 by mistake. For mobility on level surfaces, casters or wheels 
may be attached beneath base member 10. 
Around the upper perimeter of the base member 10, preferably on both side 
walls 12 and end walls 13, but at least on the two side walls 12, rail 
member 15 extends outward for engagement of the lid members 20, as shown 
in FIG. 3. Rail member 15 is a generally C-shaped guide providing the 
means for retaining the lid members 20 on the unit and at the sam time 
allowing the lid members 20 to be separated from each other by sliding 
each lid member 20 along the trough 16 formed on the upper surface of rail 
member 15. The configuration of trough 16 is concave or bevelled such that 
its interior portion is lower than its exterior to form an inward slant. 
Thus, trough 16 keeps the lid members 20 securely sealed and in place on 
base member 10, even under large load forces, since the downward pressure 
will force the runner members 27 of the lid engagement members 26 firmly 
into trough 16 rather than outward. Additionally, the upper edge of side 
walls 12 and end walls 13 may have a deflector rim 17, which is a small 
flange angled downward toward the interior of the base member 10. This 
deflector rim 17 acts to direct any liquid striking its surface into the 
interior of the unit rather than out into the environment. 
Each lid member 20 comprises a top 21, side walls 22 and an end wall 23. As 
with the base member 10, the end wall 23 and side walls 22 are preferably 
angled outward so that the open bottom is larger than the top 21. This 
allows nesting of a number of the lid members 20 within themselves or 
within the base members 10 for transport and storage. For additional 
structural strength, ribs 28 or other formations may be incorporated in 
the lid members 20 or in the base member 10. For connecting the lid 
members 20 to the base member 10, engagement means are comprising 
engagement member 26 are provided. Lid engagement member 26 is positioned 
around the bottoms of side walls 22, and preferably end wall 23, of both 
lid members 20. Lid engagement member 26 is substantially C-shaped to 
correspond to and enclose rail member 15 of the base member 10. The joint 
of the engagement member 26 to the side walls 22 and end wall 23 is 
configured to correspond to the trough 16 of the base member 10, so that a 
runner member 27 is formed. Runner member 27 will be convex or angled to 
seat within trough 16. Any downward pressure will force runner member 27 
into trough 16, maintaining the lid members 20 on base member 10. Runner 
member 27 will slide laterally within trough 16, so that the lid members 
20 can be moved transversely along rail member 15 to expose a drum 100, as 
shown in FIG. 5. Thus the lid member 20 does not need to be completely 
removed to allow access to the drum 100, such as when it is needed to pour 
liquid into said drum 100. The C-shape of engagement members 26 acts to 
clamp the lid members 20 onto rail member 15, such that the lid members 
cannot be removed from the base member 10 in the vertical direction. 
Furthermore, in the preferred embodiment where the rail member 15 and 
engagement members 16 extend around the end walls 13 and 23, respectively, 
the curvature of engagement members 26 will lock the lid members 20 in 
place on base member 10 when the lid members 20 are fully closed, by 
snapping around rail member 15 on the end walls 13. 
It is necessary that the two lid members 20 form a secure seal with each 
other when in the fully closed position to preclude rain, snow, etc. from 
entering the unit. This is accomplished by providing interlocking means, 
such as by configuring the open ends of the top 21 and side walls 23 to 
form an overlapping or mating joint. As shown in FIG. 4, one lid member 20 
is formed with an external lip 24 and the other lid member is formed with 
an internal lip 25, such that the internal lip 25 will interlock with the 
external lip 24 to form a secure seal to retain the two lid members 20 in 
a closed position. The shape of the internal lip 25 an the external lip 24 
allow the lid members 20 to be easily opened and closed. In the preferred 
embodiment, exterior lip 24 is comprised of a full ridge 31, an open ridge 
32 and a mid-plateau 33. Internal lip 25 is comprised of a full ridge 35, 
a latching ridge 34 and a mid-plateau 36. Open ridge 32 of the external 
lip 24 preferably has a small snap flange 37. To perform the closure 
operation, the lid members 20 are pushed together such that the internal 
lip 25 slides inside external lip 24. Latching ridge 34 flexes below 
mid-plateau 33 and abuts internally within full ridge 31. Full ridge 35 
seats within open ridge 32, with snap flange 37 abutting the down side of 
full ridge 35. In this manner the two lid members 20 are securely held 
together by the interlocking means, yet are easily separable by sufficient 
pulling force. The snap flange 37 and mid-plateau 36 prevent any liquids 
or debris from entering the unit when the lid members 20 are closed. The 
end portions of engagement member 26 on the lid member 20 having external 
lip 24 are enlarged to form sleeves 29. This allows the engagement member 
26 of the lid member 20 having the internal lip 25 to fit within sleeve 29 
when the two lid members 20 are fully closed. Apertures to receive locks 
may be aligned in the sleeve 29, engagement member 26 and rail member 15 
for security purposes. It is also seen that the design of the lid members 
20 allows them to be completely removed from the base member 10 by fully 
sliding them laterally off of rail member 15 if required. 
It is preferable that the invention be constructed of a plastic material 
such as polyethylene, due to its superior structural and chemical 
resistance properties, but the apparatus may be constructed of any 
suitable material having the necessary properties of liquid 
impermeability. Construction with a plastic material allows the unit to be 
formed having a translucent base member 10. This allows easy visual 
determination of any fluid accumulation inside the unit. While the unit as 
shown is substantially rectangular, a relatively square configuration is 
possible for use with one or four drums. The overall minimum size of the 
apparatus is a function of the number of drums to be contained within. 
Regulations usually require that the volume of the base member 10 be 
either at least 10 percent of the total capacity of all the drums 
contained within the unit or 10 percent greater than the largest single 
drum in the group, whichever amount is greater. For example, if a 55 
gallon drum is the largest container size in the unit, then the base 
member 10 must have a volume greater than 60.5 gallons (55+5.5 gallons). 
The above examples were given for purposes of illustration, and it will be 
apparent to those skilled in the art that obvious substitutions and 
equivalents may be possible. The full scope and definition of the 
invention therefor is to be as set forth in the following claims.