Abstract: A module that is useful for receiving stormwater when buried in permeable media comprises a base from which a plurality of columns extends upwardly, to support two or more different-elevation horizontal plates. Each plate has a plurality of holes, through each of which a column extends. The plates are secured to the columns at their respective elevations by self-acting engaging means comprising a latch, e.g. a peg extending radially from the column, and a mating receiver, e.g., an elastically deflectable plate having a hole that receives the peg. The angular orientation around the column of the self-acting engaging means varies with the plate elevation, so that for example, the first plate is only engageable at the first elevation and the second plate is only engageable at the second elevation. A module is assembled by lifting or lowering each plate along the column lengths until the plate becomes automatically engaged at the particular plate's predetermined elevation.

Abstract: A plastic leaching chamber is provided and includes a chamber substrate constructed from a PET material and having opposing side base flanges which lie in a horizontal plane and extend lengthwise along the chamber substrate. The chamber substrate includes opposing sidewalls extending upwardly from each of the opposing side base flanges to a top of the chamber substrate and includes a lengthwise center plane which is perpendicular to the horizontal plane. The opposing sidewalls define a plurality of leaching openings having at least one tab slot opening located proximate thereto, and a plurality of louver articles constructed from at least one of a PE and a PP material. Each of the louver articles include a tab which is configured to engage a tab slot opening to securely associate the plurality of louver articles with the chamber substrate to cover the at least one leach opening.

Abstract: A disclosed corrugated end cap includes a corrugated frame having one or more corrugations defined by one or more sets of alternating peaks and valleys. The end cap also includes one or more ribs disposed in one or more of the valleys and one or more valley reinforcements disposed in the valleys and running over a top surface of the corrugated frame. For example, the one or more ribs may be configured to increase a resistance of the frame to bending. Additionally or alternatively, the top surface, a front surface, and a rear of the corrugated frame surround a recess configured to receive latch ridges from a stormwater chamber.

Abstract: A disclosed corrugated end cap includes a corrugated frame having one or more corrugations defined by one or more sets of alternating peaks and valleys. The end cap also includes one or more ribs disposed in one or more of the valleys and one or more valley reinforcements disposed in the valleys and running over a top surface of the corrugated frame. For example, the one or more ribs may be configured to increase a resistance of the frame to bending. Additionally or alternatively, the top surface, a front surface, and a rear of the corrugated frame surround a recess configured to receive latch ridges from a stormwater chamber.

Abstract: A plastic leaching chamber is provided and includes a chamber substrate constructed from a PET material and having opposing side base flanges which lie in a horizontal plane and extend lengthwise along the chamber substrate. The chamber substrate includes opposing sidewalls extending upwardly from each of the opposing side base flanges to a top of the chamber substrate and includes a lengthwise center plane which is perpendicular to the horizontal plane. The opposing sidewalls define a plurality of leaching openings having at least one tab slot opening located proximate thereto, and a plurality of louver articles constructed from at least one of a PE and a PP material. Each of the louver articles include a tab which is configured to engage a tab slot opening to securely associate the plurality of louver articles with the chamber substrate to cover the at least one leach opening.

Abstract: A disclosed corrugated end cap includes a corrugated frame having one or more corrugations defined by one or more sets of alternating peaks and valleys. The end cap also includes one or more ribs disposed in one or more of the valleys and one or more valley reinforcements disposed in the valleys and running over a top surface of the corrugated frame. For example, the one or more ribs may be configured to increase a resistance of the frame to bending. Additionally or alternatively, the top surface, a front surface, and a rear of the corrugated frame surround a recess configured to receive latch ridges from a stormwater chamber.

Abstract: A plastic tank is comprised of two parts, a base and a top, that are permanently joined to each other by welding at a circumferential joint formed by two mating flanges of the parts. Fusion weld elements are captured on the faying surfaces of the flanges of the assembled parts, and the elements are melted by internal heating of metal portions of the elements. Two spaced apart circumferential welds which define an annular space are formed. The pressure within the annular space is changed in a test procedure to verify the integrity of the welds.

Abstract: A method of making a plastic tank suitable for containing water comprises forming a tank base which is partially or fully lined with a plastic layer that is different in character or color from the plastic material of the substrate of the tank base. The tank is alternatively formed by injection molding substrate material around the core of a mold which is partially or fully covered by the liner material, and by injecting liner material into the mold to bond it to the tank base substrate in conjunction with retracting part or all of the core, to provide space in the mold for the liner material.

Abstract: A method of making a molded plastic arch shape cross section stormwater chamber having a corrugated wall comprises molding half chambers which are connected by hinges at a joint at the top of the chamber. The chambers may be compactly stored and transported in splayed out configuration. Later, upward force is applied to the hinge joint location of each chamber, so the half chambers are rotated by force of gravity, whereby a faying surface on each half chamber is urged toward the like surface of the other half chamber. The faying surfaces are then fused to each other, preferably as a result of prior heating or by melting of a fusion weld element that is captured in the space between the faying surfaces.

Abstract: A plastic tank is comprised of two parts, a base and a top, that are permanently joined to each other by welding at a circumferential joint formed by two mating flanges of the parts. The faying surfaces of the flanges of the top and base have portions in the shape of a hollow truncated cone. Fusion weld elements are captured on the faying surfaces of the flanges of the assembled parts, and the elements melted by internal heating of metal portions of the elements.

Abstract: A corrugated thermoplastic leaching chamber has sidewall louvers that define sidewall slot openings. Each louver comprises an outward extending canopy, a cap integral with the outer end of the canopy, having a down slope greater than the slope of the canopy, and a preferably concave fence at the inner end of the canopy, for inhibiting ingress of soil. The chamber may be made by first thermoforming sheet material, preferably two-layer PET plastic sheet to the shape of the chamber, followed by mechanically cutting and deforming the sidewall, to create the opening and the fence.

Abstract: The cover of a plastic tank suitable for containing water is attached to the tank base by means of alternative joints, including elastically engageable features and lock features to prevent unwanted release. The base of a plastic water tank is comprised of a substrate and a liner and is formed by means which include injection molding into a mold where the core part of the mold is surrounded in part or full by the film which forms the liner.

Abstract: A molded plastic arch shape cross section stormwater chamber having a corrugated wall comprises separately molded half chambers which are connected by coupling features at a joint region at the top of the chamber, which coupling feature optionally includes at least one locking rod running lengthwise in proximity to the joint region. Preferably, the half chambers are made in the same mold and modified so they are mirror images of each other. The half chambers may be compactly stored and transported in nested condition. Near the point of use, the chambers may be assembled.

Abstract: A corrugated thermoplastic leaching chamber has sidewall louvers that define sidewall slot openings. Each louver comprises an outward extending canopy, a cap integral with the outer end of the canopy, having a down slope greater than the slope of the canopy, and a preferably concave fence at the inner end of the canopy, for inhibiting ingress of soil. The chamber may be made by first thermoforming sheet material, preferably two-layer PET plastic sheet to the shape of the chamber, followed by mechanically cutting and deforming the sidewall, to create the opening and the fence.

Abstract: A method of making a plastic tank suitable for containing water comprises forming a tank base which is partially or fully lined with a plastic layer that is different in character or color from the plastic material of the substrate of the tank base. The tank is alternatively formed by injection molding substrate material around the core of a mold which is partially or fully covered by the liner material, and by injecting liner material into the mold to bond it to the tank base substrate in conjunction with retracting part or all of the core, to provide space in the mold for the liner material.

Abstract: A method of making a molded plastic arch shape cross section stormwater chamber having a corrugated wall comprises molding half chambers which are connected by hinges at a joint at the top of the chamber. The chambers may be compactly stored and transported in splayed out configuration. Later, upward force is applied to the hinge joint location of each chamber, so the half chambers are rotated by force of gravity, whereby a faying surface on each half chamber is urged toward the like surface of the other half chamber. The faying surfaces are then fused to each other, preferably as a result of prior heating or by melting of a fusion weld element that is captured in the space between the faying surfaces.

Abstract: A molded plastic arch shape cross section stormwater chamber having a corrugated wall comprises separately molded half chambers which are connected by hinges at a joint at the top of the chamber. The chambers may be compactly stored and transported in splayed out configuration, with the arch is flattened out and the base flanges are widely separated. Near the point of use, the chambers are hinged to their arch shape use configuration. Preferably, the half chambers are substantially identical and are made in the same mold. Methods of molding the chambers enable providing a larger or smaller corrugation at one end of a chamber made from substantially identical half chambers.

Abstract: The cover of a plastic tank suitable for containing water is attached to the tank base by means of alternative joints, including elastically engageable features and lock features to prevent unwanted release. The base of a plastic water tank is comprised of a substrate and a liner and is formed by means which include injection molding into a mold where the core part of the mold is surrounded in part or full by the film which forms the liner.

Abstract: A molded plastic arch shape cross section stormwater chamber having a corrugated wall comprises separately molded half chambers which are connected by coupling features at a joint at the top of the chamber. Preferably, the half chambers are substantially identical and are made in the same mold. The half chambers may be compactly stored and transported. Near the point of use, the chambers may be assembled.

Abstract: A molded plastic tank, optionally a septic tank, for containing liquid, comprises two injection molded plastic half tanks that have concave exterior walls and integral flanges, and that nest within each other for shipment or storage. Lengthwise ends of the half tanks have grips, for manual or machine lifting of the half tank from the top of a concave-down stack of half tanks, and for then assembling whole tanks. A sling is used to machine lift one or several half tanks by attachment to the grips or to lifting lugs at the top of the half tank. A corrugated septic tank having spaced apart access port regions has a grid of ribs in the exterior top valley corrugations and running across the access port region, to provide strength during testing and use.