AU2006201697B1

AU2006201697B1 - Effluent Dispersal System

Info

Publication number: AU2006201697B1
Application number: AU2006201697A
Authority: AU
Inventors: Ronald Frederick Hopley
Original assignee: RONALD HOPLEY
Current assignee: Hopley Beverley Elizabeth
Priority date: 2005-05-12
Filing date: 2006-04-24
Publication date: 2006-11-09
Anticipated expiration: 2026-04-24
Also published as: AU2006201697C1

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Actual Inventor Address for service is: Ronald Frederick Hopley Ronald Frederick Hopley WRAY ASSOCIATES Level 4, The Quadrant 1 William Street Perth, WA 6000 Attorney code: WR Invention Title: Effluent Dispersal System The following statement is a full description of this invention, including the best method of performing it known to me:- Effluent Dispersal System Field of the Invention The present invention relates to an effluent dispersion system for a septic sewerage system. It is particularly directed to a system enabling broader dispersion of the water from the effluent to enable it to be used for watering of lawns or the like, but is not limited to this purpose.

Background Art Septic sewerage systems are widely used in rural environments. As is well known, such systems comprise a tank system wherein septic action breaks down the raw effluent over a period of time. Excess liquid is then able to be directed away from the tank system, while solid material sinks to the bottom of the tank.

The liquid comprises water with certain sewerage products therein. These products tend to be high in biological nutrients. These are disposed of by means of leech drains or the like, wherein the liquid is allowed to soak into the ground at a depth below the surface.

In many places where septic sewerage systems are used, water is a scarce commodity. Water for inessential use such as the watering of lawns is limited or not utilized. Nevertheless, a considerable volume of water is disposed of as waste through the septic system associated with the house. However, it has not been practical to utilize this water for the watering of lawns. The regulatory bodies require that the dispersion pipes be buried at least 300mm below a lawn and at such depths, they have not been effective in distributing the water of the effluent sufficiently to provide reasonably even watering. Conventionally, the only area adequately watered is a narrow strip immediately above the dispersion pipe.

-3- The above description is for the purposes of illustration only and is not intended to be limited to the dispersal of effluents in domestic situations or in relation to effluent being sourced from septic sewerage systems.

Disclosure of the Invention Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

In addition throughout the specification the reference to a "permeable" material shall be taken to include any permeable or porous material.

According to one aspect the invention resides in an effluent dispersion system comprising a subterranean zone in the ground defined above an impervious layer, a ground support member supported in the zone, to lie above the layer and extending over a portion of the layer to define a space above the layer, the walls of the ground support member which define the perimeter of the space above the layer being permeable to liquids, a delivery means which in use is to be connected to a source of effluent, the ground support and the layer being overlaid by a permeable soil to define the zone and wherein the zone is overlaid by top soil.

According to a preferred feature of the invention the area of the layer is less than the area of the zone and the permeable soil contained within the zone extends to at least one side of the layer to be in direct contact with the surrounding ground.

According to a preferred feature of the invention the layer extends substantially beyond the area of the layer overlaid by the ground support member. According to a preferred feature of the invention the area of the layer is a multiple of twice or more of the area of the layer overlaid by the ground support member.

According to a preferred feature of the invention upper surface of the top soil comprises a grassed or lawn area.

-4- O According to a preferred feature of the invention the layer is defined by an impervious sheet material. According to a preferred feature of the invention the O impervious sheet material comprises a plastics material. According to a N preferred feature of the invention the sheet plastics material is of PVC.

According to a preferred feature of the invention the walls of the ground support Smember are covered by a fabric or membrane capable of preventing soil entering a the space but which is permeable to liquid.

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0 According to a preferred feature of the invention the delivery means comprises a duct located within the space having an inlet which in use is to be connected to a source of effluent, said duct being adapted to deliver the effluent into the space along the length of the duct According to a preferred feature of the invention the permeable soil comprises an amended soil which is adapted to absorb some of the dissolved compounds contained within the effluent.

According to a preferred feature of the invention the dissolved compounds comprise compounds containing phosphorus and/or nitrogen.

According to another aspect the invention resides in a ground support member for use with an effluent dispersal system of the form as described above wherein, the ground support member is substantially semi-cylindrical in cross-section with the planar face lowermost and overlying the layer.

According to a preferred feature of the invention the planar face is open.

According to a preferred feature of the invention the open lower face is associated with brace members which extend transversely across the lower face to interconnect the opposed edges. According to a preferred feature of the invention at least a portion of the edges which surround the planar open face are provided with an edge of increased area. According to a preferred feature of the invention the edge is defined by at least one laterally directed flange. According

NO

O to a preferred feature of the invention the ground support member comprises a plurality of panels mounted in an overlying relationship.

NAccording to another aspect the invention resides in a ground support member for use with an effluent dispersal system of the form as described above wherein the ground support member has the cross-section of a right angled quadrilateral Swith one planar face lowermost and overlying the layer.

N According to a preferred feature of the invention the ground support member 0 comprises a plurality of interconnected modules. According to a preferred feature of the invention the modules are interconnected in an end to end relationship. According to a preferred feature of the invention the modules are of a generally cubic configuration.

According to a preferred feature of the invention the ground support member is formed of a metallic material covered by a corrosion resistant coating. According to a preferred feature of the invention the ground support member is formed of galvanised steel. According to a preferred feature of the invention the corrosion resistant coating comprises a plastics material.

According to a preferred feature of the invention the ground support member is formed from a plastics material.

According to a preferred feature of the invention the walls of the ground support member are formed at least in part from a mesh or grating-like material.

The invention will be more fully understood in the light of the following description of several specific embodiments.

Brief Description of the Drawings The description is made with reference to the accompanying drawings, of which: Figure 1 is a schematic sectional end elevation of the effluent dispersion system according to the first embodiment; -6- Figure 2 is a sectional plan of an effluent dispersion system along line 2-2 of Figure 1; Figure 3 is a schematic isometric view of the ground support member according to the first embodiment; Figure 4 is a schematic exploded sectional end elevation of the ground support member and distribution pipe according to the second embodiment; Figure 5 is a sectional plan view of the effluent dispersion system according to the third embodiment; and Figure 6 is a schematic sectional end elevation of the effluent dispersion system according to the fourth embodiment.

Best Mode(s) for Carrying Out the Invention The embodiments of the invention described below are directed to an effluent dispersion system which is to be connected to a septic sewerage system to receive the effluent which is delivered from the septic system.

The first embodiment as shown at Figures 1 to 3 comprises an effluent dispersion system 11 adapted to be supplied with effluent by an pipe 12 which conveys the effluent from a septic tank (not shown). The dispersion system of the first embodiment is adapted to disperse the effluent underneath a grassed area 14 of ground.

The effluent distribution system comprises an impervious layer 23 which is provided by an impervious plastic sheet which extends over an area of ground.

The impervious sheet 23 is typically of plastics material such as PVC sheeting.

To provide the area of ground, an area is excavated or formed to provide a level area within a depression or on the ground and the sheet is laid to overlie a portion of the area. A distribution pipe 21 is laid over the sheet intermediate of its edges and is connected to the outlet pipe 12. In addition the impervious sheet 23 is covered by a relatively thin covering layer 25 of sand or a like permeable medium through which the effluent would be able flow readily. Typically this covering layer 25 will be in the range of 10mm to 50mm thick. The distribution pipe 21 is positioned on the covering layer 25. The impervious sheet 23 is of sufficient length to extend a beyond the ends of the distribution pipe typically in the order of 1.5m to 2m at each end.

A ground support member 31 is located over the distribution pipe 21 to define a space above and around the distribution pipe 21. The ground support member 31 comprises a shell 32 which has a semicircular cross-section where the curved walls and the end walls are closed and the planar face is open whereby when the ground support is in position the open face is caused to be lowermost. The edges of the open face are formed with a flange 33 to provide support for the ground support member on the impervious sheet. The closed curved walls and the end walls of the shell 32 are formed of a mesh material which is formed from a corrosion resistant material such as a galvanised steel. If desired the mesh is covered with a plastics coating. Altematively, a mesh formed entirely from plastics material may be used. The mesh is typically 25mm square mesh, although other gauges of mesh may be selected as is deemed appropriate. The curved and end walls of the shell are covered by a permeable fabric or membrane 38. An example of such a membrane is one marketed under the trade mark GEOFABRIC. The function of the fabric or membrane 38 is to prevent the entry of soil into the space defined by the ground support member 31. The radius of the ground support member 31 is selected at least in part according to regulatory requirements specifying the minimum depth of the distribution pipe 21 below the ground surface but it is anticipated that the depth will be approximately 300mm. As shown at Figure 3 the ground support 31 is provided with one or more inspection ports 34 which are each closed by removable closures 35 which can be accessed for inspection of the space 39 defined by the ground supports 31.

Subsequent to the location of the ground support member in position together with then permeable fabric or membrane the ground support member and the excavated or levelled area including the impervious area defined by the impervious sheet is covered by a layer 42 of amended soil which has the capacity to absorb at least some undesirable compounds from the effluent such as those containing phosphorus and/or nitrogen. The layer 42 of amended soil -8will extend beyond the perimeter of the impervious layer and will be in direct contact with the surrounding soil of the site.. The layer of amended soil is then overlaid by top soil 41 onto which a lawn 14 can be planted The ground support member 31 extends for at least the length of the distribution pipe 21 and is positioned such that the distribution pipe is located centrally within it. It is anticipated that the distribution pipe will be of the order of 25 to mm in diameter (width) so that the diameter of the space defined by the ground support member at the covering layer is a multiple of the diameter of the distribution pipe. The radial flanges 33 are adapted to sit on the covering layer to support the load of soil 40 placed above the ground support member as well as other loading which may occasionally be placed above the lawn-area. Once soil is placed above the ground support member 31, the semi-circular profile is maintained by the soil. This enables the ground support member to accommodate a quite high loading.

The free space defined within the ground support member and which is to the exterior of the distribution pipe prevents effluent from being absorbed by the amended soil surrounding the ground support member until it has dispersed laterally to the edges of the open face of the ground support member. As a result of the dispersion arrangement of the embodiment, after the effluent flows from the distribution pipe 21 it passes to the covering layer 25 and spreads outwardly from the into the surrounding amended soil while the impervious sheet 23 prevents preventing absorption into the ground below the impervious sheet 23. Once beyond the ground support member 31, the effluent will be absorbed by the amended soil above the impervious sheet 23 and permeate laterally from the ground support member this is facilitated to some extend by the sand layer which overlies the impervious sheet 23. Capillary action causes the effluent to spread upwardly from the impervious layer over substantially the full area of the impervious layer to a level at which it is accessible to the roots of the grass of the lawn-area 14. It is anticipated that the even distribution of the effluent provides over the area of the impervious sheet will facilitate substantially uniform distribution of the effluent to the lawn area 14 and therefore it is anticipated it will provide a reasonably even growth of grass over the lawn area.

-9- The second embodiment as shown at Figure 4 comprises a ground support member of the same form as in the case of the first embodiment but which utilises as set of transverse brace elements 36 which extend across the open face of the shell and engage the opposed flanges 33 prevent the side walls of the shell from spreading. The braces comprises strips which are formed with a lip 37 which will engage with the respective flanges to prevent outward movement of the flange. In addition the second embodiment does not utilise the thin covering layer of sand or a like permeable medium between the ground support member and the impervious layer of the first embodiment. Instead the open face is closed by a layer 40 of the permeable fabric or membrane.

The third embodiment of Figure 5 comprises one in which the capacity of the system is increased by providing a pair of ground supports which are arranged to be connected in parallel.

The fourth embodiment as shown at Figure 6 is of the same form as the previous embodiments with the exception that the ground support member has a substantially rectangular cross section and is composed of a number of panels 32 support and which are mounted in a face to face relationship The panels are formed of a suitable plastics material and are each formed as an open grate where the cavities defined in each panel by the grate configuration jointly define the space 39 and are open to the faces of the ground support. In addition the webs of the grate are formed with apertures or openings to will permit the flow of liquids along the length of the ground. The number of panels uses will depend upon the desired height of the ground support member and the volume required of the interior of the ground support member. The ground support can be formed of a continuous length of material or from a number of modules which are interconnected in an end to end relationship. If the capacity of the system is to be varied the number of panels which define the ground support can be varied.

Clearly, the effectiveness of the systems of the first, second, third and fourth embodiments will depend upon the volume of effluent available which will limit the area of lawn which can be adequately irrigated. The systems of the first and second embodiments are intended to be supplied from a dwelling providing a relatively small effluent volume such as a one or two bedroom dwelling. Where a larger volume of effluent is available, a larger lawn area can be accommodated.

However, with such an area, it becomes appropriate to expel the effluent through a plurality of distribution pipes spaced at intervals beneath the lawn area, as is now described in respect of the third embodiment as shown at Figure 6 where the arrangements of the first and second embodiments are duplicated to provide an extended zone 42 of amended soil which accommodates two impermeable layers 23 in spaced side by side relationship each accommodating a ground support member 31 and associated distribution pipes 21 which are each fed from the same source pipe 12.

If desired the distribution pipes can be selectively opened to the source pipe 12 whereby one distribution pipe of a pair is used for a period of time and then the effluent flow diverted to the other distribution pipe of the pair. This intermittent use provides the ground surrounding the distribution pipe with an opportunity to recover from the effluent drainage.

According to a further embodiment each impervious layer may be provided with two or more ground support members and associated distribution pipes.

According to a further embodiment the ground support member or members are non-linear and are convoluted to increase the surface area available for the distribution of effluent into the zone amended soils and associated distribution pipes.

According to a further embodiment the amended soil of previous embodiments may be replaced by a course sand.

Those skilled in the art will recognize that the embodiments may be adapted in many ways while retaining the essential features of the invention. For instance, the ground support member might provided from a half section of a plastic pipe.

Such a semi-cylindrical section could be rested on a pair of suitable support strips of corrosion resistant material. It is to be understood that such adaptations are to be considered as being within the scope of the invention.

Claims

1. An effluent dispersion system comprising a subterranean zone in the ground defined above an impervious layer, a ground support member supported in the zone, to lie above the layer and extending over a portion of the layer to define a space above the layer, the walls of the ground support member which define the perimeter of the space above the layer being permeable to liquids, a delivery means which in use is to be connected to a source of effluent, the ground support and the layer being overlaid by a permeable soil to define the zone and wherein the zone is overlaid by top soil.

2. An effluent dispersion system as claimed at claim 1 wherein the area of the layer is less than the area of the zone and the permeable soil contained within the zone extends to at least one side of the layer to be in direct contact with the surrounding ground.

3. An effluent dispersion system as claimed at claim 1 or 2 wherein the layer extends substantially beyond the area of the layer overlaid by the ground support member.

4. An effluent dispersion system as claimed at claim 3 wherein the area of the layer is a multiple of twice or more of the area of the layer overlaid by the ground support member. An effluent dispersion system as claimed at any one of the preceding claims wherein upper surface of the top soil comprises a grassed or lawn area.

6. An effluent dispersion system as claimed at any one of the preceding claims wherein the layer is defined by an impervious sheet material.

7. An effluent dispersion system as claimed at claim 6 wherein the impervious sheet material comprises a plastics material. -12-

8. An effluent dispersion system as claimed at claim 7 wherein the sheet plastics material is of PVC.

9. An effluent dispersion system as claimed at any one of the preceding claims wherein, the ground support member is substantially semi- cylindrical in cross-section with the planar face lowermost and overlying the layer. effluent dispersion system as claimed at claim 9 wherein the planar face is open.

11.An effluent dispersion system as claimed at claim 10 wherein the open lower face is associated with brace members which extend transversely across the lower face to interconnect the opposed edges.

12.An effluent dispersion system as claimed at claim 10 or 11 wherein at least a portion of the edges which surround the planar open face are provided with an edge of increased area.

13.An effluent dispersion system as claimed at claim 12 wherein the edge is defined by at least one laterally directed flange.

14.An effluent dispersion system as claimed at any one of claims 9 to 13 wherein the ground support member comprises a plurality of panels mounted in an overlying relationship.

15.An effluent dispersion system as claimed at any one of claims 1 to 8 wherein the ground support member has the cross-section of a right angled quadrilateral with one planar face lowermost and overlying the layer.

16.An effluent dispersion system as claimed at claim 15 wherein the ground support member comprises a plurality of interconnected modules. -13- \O

17.An effluent dispersion system as claimed at claim 16 wherein the modules are interconnected in an end to end relationship. ID18.An effluent dispersion system as claimed at claim 16 or 17 wherein the modules are of a generally cubic configuration.

19.An effluent dispersion system as claimed at any one of the preceding claims wherein the walls of the ground support member are formed at IDleast in part from a mesh or grating-like material. effluent dispersion system as claimed at any one of the preceding claims wherein the ground support member is formed of a metallic material covered by a corrosion resistant coating.

21.An effluent dispersion system as claimed at claim 20 wherein the ground support member is formed of galvanised steel.

22.An effluent dispersion system as claimed at claim 20 wherein the corrosion resistant coating comprises a plastics material.

23. An effluent dispersion system as claimed at any one of claims 1 to 19 the ground support iember is formed from a plastics material.

24.An effluent dispersion system as claimed at any one of the preceding claims wherein the walls of the ground support member are covered by a fabric or membrane capable of preventing soil entering the space but which is permeable to liquid. effluent dispersion system as claimed at any one of the preceding claims wherein the delivery means comprises a duct located within the space having an inlet which in use is to be connected to a source of effluent, said duct being adapted to deliver the effluent into the space along the length of the duct -14-

26.An effluent dispersion system as claimed at any one of the preceding claims wherein the permeable soil comprises an amended soil which is adapted to absorb some of the dissolved compounds contained within the effluent.

27.An effluent dispersion system as claimed at claim 26 wherein the dissolved compounds comprise compounds containing phosphorus and/or nitrogen.

28.An effluent dispersion system substantially as herein described with reference to the accompanying drawings.

29.A ground support member for use with an effluent dispersal system of the form as claimed at any one of the preceding claims wherein, the ground support member is substantially semi-cylindrical in cross-section with the planar face lowermost and overlying the layer. ground support member as claimed at claim 29 wherein the planar face is open.

31.A ground support member as claimed at claim 30 wherein the open lower face is associated with brace members which extend transversely across the lower face to interconnect the opposed edges.

32.A ground support member as claimed at claim 30 or 31 wherein at least a portion of the edges which surround the planar open face are provided with an edge of increased area.

33.A ground support member as claimed at claim 32 wherein the edge is defined by at least one laterally directed flange.

34.A ground support member as claimed at any one of claims 29 to 33 wherein the ground support member comprises a plurality of panels mounted in an overlying relationship. \O 0 35.A ground support member for use with an effluent dispersal system of the c form as claimed at any one of the preceding claims wherein the ground O support member has the cross-section of a right angled quadrilateral with IN one planar face lowermost and overlying the layer.

36.A ground support member as claimed at claim 35 wherein the ground Ssupport member comprises a plurality of interconnected modules. S37.A ground support member as claimed at claim 36 wherein the modules are interconnected in an end to end relationship.

38.A ground support member as claimed at claim 36 or 37 wherein the modules are of a generally cubic configuration.

39.A ground support member as claimed at any one of claims 29 to 38 wherein the walls of the ground support member are formed at least in part from a mesh or grating-like material. ground support member as claimed at any one of claims 29 to 39 wherein the ground support member is formed of a metallic material covered by a corrosion resistant coating.

41.A ground support member as claimed at claim 40 wherein the ground support member is formed of galvanised steel.

42.A ground support member as claimed at claim 40 wherein the corrosion resistant coating comprises a plastics material.

43.A ground support member as claimed at any one of claims 29 to 39 the ground support member is formed from a plastics material. -16-

44.A ground support substantially as herein described with reference to the accompanying drawings Dated this Twenty Fourth day of April 2006. Ronald Frederick Hopley Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant