Abstract: Arch shape cross-section leaching and stormwater chambers are connected together so that swiveled angling is obtained at the joint. Angling is accomplished by means of an integral or detachable dome end comprising a conical section. A like chamber with an ordinary end mates by overlapping the dome. Or a like chamber may have an opposing and overlapping end, which also comprises a dome. A coupling for connecting two ordinary end chambers is comprised of two spaced apart conical domes spaced apart by a connector. The connector between the domes is optionally straight or angled. The couplings enable chambers to be connected at diverse angles to each other, as well as to be connected parallel with offset, i.e., with zigzag path.

Abstract: A method for treating wastewater in a leaching field comprises forming and burying in soil a continuous curve arch shape cross section injection molded thermoplastic leaching chamber. The chamber has inwardly curving sidewalls perforated with closely spaced horizontal slots and peak corrugations which are closely spaced apart on about 8 inch center-to-center distance or less. The chamber configuration in combination with certain plastic material properties and thickness provide strength sufficient to meet regulatory requirements when the soil above the buried chamber is subjected to load.

Abstract: A molded thermoplastic tank for use as a septic tank or storage tank when buried in soil has a combination of transverse peak and valley corrugations in combination with one or more lengthwise peak corrugations, to provide in effect a molded-in beam structure. The lengthwise corrugations may be at the top, between spaced apart access ports, along the bottom. In one embodiment, the top has an H-shape pattern beam structure. In another embodiment separately formed plastic beams and or a combination of vertical and horizontal struts are inside the tank.

Abstract: A splash plate for use with an end cap or end portion of a chamber is provided, wherein the end cap or end portion defines an end cavity having an open end cavity bottom and includes an opening for containing a waste water pipe that introduces waste water into the end cavity. The splash plate includes a base panel for covering the end cavity bottom such that waste water introduced into the end cavity contacts at least a portion of said base panel and a means for positionably securing the splash plate relative to the end cap or end portion.

Abstract: An arch shape cross section thermoplastic leaching chamber, having sidewall slot perforations which flare inwardly, is made using a mold comprised of a mold cavity part and an inwardly retractable mold core part. The core part has opposing side slides with projections that define the perforations; they are separated by a center block. The center block moves downwardly and the slides move inwardly, under action of slide rods built into the mold core, to enable a molded chamber to be removed from the mold.

Abstract: A molded plastic arch shape cross section corrugated leaching chamber has opposing perforated sidewalls running up from feet. Each foot comprises a horizontal flange, an outer-edge fin, and transverse ribs, which define compartments on the flange surface. Drain holes through the flange within each compartment enable water from nearby sidewall perforations to flow downwardly into the soil during use.

Abstract: A leaching chamber has sidewall perforations which flare inwardly, so that the smallest perforation dimension is on the exterior surface of the sidewall. The basic axes of the perforations run downwardly toward the chamber base, as the axes run from the inside to outside of the chamber. Mold cores having inwardly retracting slides, and which move in complex ways, are used to form the chamber. Thus, perforations are present down near the base flange of the sidewall, even though the base flange has an upwardly extending fin.

Abstract: A method for treating wastewater in a leaching field comprises forming and burying in soil a continuous curve arch shape cross section injection molded thermoplastic leaching chamber. The chamber has inwardly curving sidewalls perforated with closely spaced horizontal slots and peak corrugations which are closely spaced apart on about 8 inch center-to-center distance or less. The chamber configuration in combination with certain plastic material properties and thickness provide strength sufficient to meet regulatory requirements when the soil above the buried chamber is subjected to load.

Abstract: A continuous curve arch shape cross section corrugated injection molded thermoplastic chamber is provided and includes a body having a multiplicity of peak and valley corrugations running along the curve of the arch shape, wherein the multiplicity includes opposing sidewalls, each having a foot, opposing chamber ends connected to the body, the ends shaped to form joints with the ends of like chambers, a multiplicity of sprues, within spaced apart valleys, at elevations intermediate the foot and apex of the chamber, wherein each sprue has a first runner running upwardly alone the valley in direction of the apex, and a second runner running downwardly along the valley toward the foot, a base runner connected to the bottom of the second runner, running lengthwise along the foot of the chamber; and at least one third runner connected to the base runner and running upwardly along a peak adjacent the valley.

Abstract: An injection molded plastic corrugated leaching or storm water chamber has a peak corrugations segment with a flattened and thickened web. The web is the portion of the corrugation which runs from the peak to the floor of the adjacent valley. Preferably, flattened web segments are at the apexes of adjoining corrugations, to create an increased thickness band region, running lengthwise along the chamber from an injection nozzle location or sprue. The flattened web segments enable better melted plastic flow during molding, without increasing nesting height.

Abstract: A continuous curve arch shape cross section leaching chamber made of molded thermoplastic has closely spaced corrugations and sidewalls, portions of which are perforated with horizontal slots. Either or both of the slot height and the local wall thickness of the sidewall portion which defines the slots may vary with slot elevation from the base. The chambers are free of interior and exterior strengthening ribs. They provide high interior storage volume and high leaching area in combination with low mass or weight of plastic material. An exemplary 34 inch wide chamber has more than 1.5 cubic feet of water storage volume per foot, less than 4 pounds weight of thermoplastic material per foot, and at least 30 square inches of slot-provided leaching area per foot.

Abstract: A continuous curve arch shape cross section leaching chamber made of molded thermoplastic has closely spaced corrugations and sidewalls, portions of which are perforated with horizontal slots. Either or both of the slot height and the local wall thickness which defines the slots may vary with slot elevation from the base, so that a perforated sidewall configuration is achieved which resists entry of surrounding soil.

Abstract: A molded plastic corrugated arch shape cross section leaching chamber has a dome end for forming a pivotable joint with a like chamber. The dome of the dome end has one or more preferably trapezoid shape shallow surface depressions, for strength. The depressions are specially placed so that soil cannot enter the interior of the chambers, regardless of the angle between the chambers.

Abstract: A continuous curve arch shape cross section leaching chamber made of molded thermoplastic has closely spaced corrugations and sidewalls, portions of which are perforated with horizontal slots. Either or both of the slot height and the local wall thickness which defines the slots may vary with slot elevation from the base, so that a perforated sidewall configuration is achieved which resists entry of surrounding soil. In one embodiment, the slotted sidewall has slots with all the same slot openings and the wall thickness decreases with elevation.

Abstract: Arch shape cross-section leaching and stormwater chambers are connected together so that swiveled angling is obtained at the joint. Angling is accomplished by means of an integral or detachable dome end comprising a conical section. A like chamber with an ordinary end mates by overlapping the dome. Or a like chamber may have an opposing and overlapping end, which also comprises a dome. A coupling for connecting two ordinary end chambers is comprised of two spaced apart conical domes spaced apart by a connector. The connector between the domes is optionally straight or angled. The couplings enable chambers to be connected at diverse angles to each other, as well as to be connected parallel with offset, i.e., with zigzag path.

Abstract: Arch shape cross-section leaching and stormwater chambers are connected together so that swiveled angling is obtained at the joint. Angling is accomplished by means of an integral or detachable dome end comprising a conical section. A like chamber with an ordinary end mates by overlapping the dome. Or a like chamber may have an opposing and overlapping end, which also comprises a dome. A coupling for connecting two ordinary end chambers is comprised of two spaced apart conical domes spaced apart by a connector. The connector between the domes is optionally straight or angled. The couplings enable chambers to be connected at diverse angles to each other, as well as to be connected parallel with offset, i.e., with zigzag path.

Abstract: A molded plastic corrugated arch shape cross section leaching chamber, which is adapted for connection to a like chamber with a pivotable connection, has a hanger for a dosing pipe which is contained within the concavity of a peak corrugation of the end of a mating chamber.

Abstract: A splash plate for use with an end cap or end portion of a chamber is provided, wherein the end cap or end portion defines an end cavity having an open end cavity bottom and includes an opening for containing a waste water pipe that introduces waste water into the end cavity. The splash plate includes a base panel for covering the end cavity bottom such that waste water introduced into the end cavity contacts at least a portion of said base panel and a means for positionably securing the splash plate relative to the end cap or end portion.

Abstract: An adapter is used with a leaching chamber or like article to change the invert elevation for a pipe which carries water to the article. The first end of the adapter fits a hole or other port on the article. The body of the adapter rotates about that first end, changing the elevation of the second end relative to the base. Stops on the adapter body limit rotation: in one direction so the first and second ends are vertically aligned; and in the opposing direction so that the lengthwise axes of the first and second ends lie in an inclined plane. Thus, three positive invert elevations can be set for an inlet pipe for a particular article: a first and second at each limit of rotation of the adapter, and a third and lowermost elevation, wherein the adapter is not used.

Abstract: A continuous curve arch shape cross section leaching chamber made of molded thermoplastic has closely spaced corrugations and sidewalls which are perforated with slots which slope downwardly, running from interior to exterior of the chamber. The slot height and or wall thickness vary with slot clevation from the base, to achieve a desired minimum Soil Threshold Angle in the slots, where said Angle parameter relates to resistance to entry of surrounding soil. Slotted wall thickness is less than about two times the thickness of the basic chamber wall thickness elsewhere. The chamber has properties and performance approximating prior art chambers, but has substantially less normalized weight and total weight.