Patent ID: 7008138

Claim:
An end cap for closing off the open end of an arch shape cross section leaching chamber or storm water chamber, having x, y and z axes, which comprises: an arch shape first end lying in a vertical y-z plane, for mating the end cap with the end of a chamber; a second end, lying in horizontal x-y plane, for supporting the end cap on a surface, having a contour which runs outwardly from the plane of the first end; a shell having a convex shape exterior surface, connecting the first end and the second end; and, at least three buttresses, projecting outwardly from the exterior surface of the shell, the first buttress lying along the x-axis; the second and third buttresses disposed on opposing sides of the shell relative to the first buttress; each buttress comprising a surface portion shaped for receiving a pipe through which water may be flowed to or from the interior of the end cap; wherein each buttress surface portion faces in a horizontal plane direction which is different from the others; and wherein the surface portion of at least one buttress comprises two sub-portions, one above the other, the sub-portion surfaces slightly displaced relative to each other, to form a step therebetween.