AU3506899A

AU3506899A - Underground drainage system

Info

Publication number: AU3506899A
Application number: AU35068/99A
Authority: AU
Inventors: Humberto Urriola
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-12-14
Filing date: 1999-06-16
Publication date: 1999-08-19

Description

Our Ref: URR35 P/00/0011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Applicant: Applicant and address: Humberto Urriola 55 Romney Road St Ives NSW 2075 Australia Address For Service: Invention Title: Inventors: Paul R. Taylor Associates PO Box 742 Spit Junction NSW 2088 Australia Underground Drainage system Humberto Urriola The following statement is a full description of this invention, including the best method of performing it known to me: 4352.doc The present invention relates to a drainage system and in particular to such a system designed to not only collect excess water but to return purified water to the environment as close to the collection point as possible. The aerated and pure water allows aerobic neg-entropic activities in the soil horizon both above and in the drainage strata itself.

For many centuries the development of land has involved installation of drainage infra-structures commencing with collection points such as gutters and down pipes, kerbing and guttering, grates and sumps, open or enclosed troughs and canals, 10 detention ponds and others. These primary collection points lead in turn into pipes which in turn feed large pipes or storm water canals which in turn lead eventually to creeks and rivers and finally the sea. This existing method with its concentration of run off and resultant depletion of the oxygen content of the water, is one of the major causes of water contamination and depletion of flora and fauna on the planet since 15 Roman times.

:0:0 The continuing urbanisation of the natural countryside which replaced permeable topsoil with impervious surfaces disturbs, alters and contaminates the natural surface water and ground water tables, and results in a dramatic increase in contaminated surface runoff with resulting floods both minor and major, as water which would normally have been absorbed by the soil and flora, is concentrated in man made impermeable channels where the oxygen content of the water is greatly decreased from that of the water in the natural environment.

Water entering into these impermeable anaerobic systems undergoes entropic degradation as much litter, oil and other impurities find their way into the system often via kerbsides. The oxygen content of the water which is lowered by mixing organic matter, and pollutants also continually decreases as it passes through the system towards the river or the sea.

The accumulation of rubbish and silt in the drainage systems cause the formation of stagnant anaerobic pools which can be breeding grounds for mosquitoes and diseases, especially in open drainage channels.

Much silt and soil also finds its way into drainage systems and furthermore the additional burden on creelks and rivers causes yet further erosion resulting in disastrous siltation, lowering of oxygen content of rivers, lakes and eventually the sea.

This is a major ecological problem oftoday.

Sports fields are becoming major offenders in ecology. Playing surfaces are becoming unplayable due to the unbalance of water in the first soil horizon. Too much or not enough water results in the degradation of the physical structure of the soil. The resultant retardation of the vegetation induces the use of large amounts of chemicals as a solution to keep the fields grassed. However this increases the contamination of the run off water.

When the above mentioned undesirable situation is compared with the natural undeveloped situation it can be seen that far larger volumes of run off are being transported far greater distances at an increasing rate. In natural systems, rainwater i filtered through the ground maintaining a healthy oxygen content and is being continually cleanses by such filtration through the soil, sand and rock strata and transport slowly by aquifers.

It is consequently an object of the present invention to more closely emulate natural drainage patterns by provision of an underground system which provides not only for collection and transport of stormwater, but also for return of the stormwater to the environment through porous surfaces at a locality as close as possible to the point of collection.

It is also an object of this invention to provide a filtration system in the form of a silt trap to filter the stormwater as it passes through the silt trap.

In one broad form the invention consists in a silt trap comprising a water 15 impervious container having an opening in its base; a layer of perforated modular wall panels, lining the inner walls and the base of the container and defining a passageway in communication with the said opening in the base of the container; a bag of water permeable geotextile supported on the modular wall panels; and an inlet pipe connected to said bag, such that solids, carried by water into said bag, are retained in said bag and the filtered water passes along the passageway defined by the modular wall panels and out through the opening in the base of the container.

Preferably the perforated modular wall panels comprise two planar spaced apart perforated surfaces with a plurality of rigid spacer members therebetween, maintaining said surfaces in a fixed spaced relationship with each other.

Preferably the opening in the base of the container is connected to piping formed by the said modular wall panels connected end of end and wrapped in geotextile.

Preferably the container has a removable water impervious lid to allow the bag 10 of water permeable textile to be removed.

The invention provides an underground drainage system comprising storage V. and/or piping which are made of porous materials to allow water to flow in all directions through the material, such that in use water permeates from said storage 15 and/or piping into the surrounding earth. Hence embodiments of the present invention have the ability to alter the disruption of the natural water by replacing the impervious entropic man made systems with a neg-entropic natural system, with resultant 0: 0 0.

S"improvement in the quality of flora and fauna.

Permeable topsoil or surface structures with small compaction coefficient are important to ensure water penetration into the system. In preferred embodiments of the present invention, aerobic drainage will electrostatically position soil fines above the hydrophilic geotextile which surrounds the storage/piping of the present invention.

Fine matter is repelled and replaced by larger particles allowing clean oxygenated water to pass there through, thus improving drainage capabilities. This will stop thf normal size stratification of soil and thus create the necessary conditions for healthy and fast growth of flora and the resultant proliferation of fauna. Plans thus have the ideal soil conditions, without the need of artificial fertilizer. Fauna and flora proliferate in a balanced manner.

A preferred form of the invention will now be described with the aid of the accompanying drawings in which: Figure 1 illustrates a silt collection tank according to the preferred 10 embodiment of this invention.

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Figure 2 illustrates a side view of the silt collection tank of Figure 1.

Figure 3 illustrates a modification of the silt collection tanks of Figures 1 and 15 2.

oo During rain, because of the extensive use of bitumen, concrete and buildings the natural absorption of water into the soil is limited to small areas of parks and gardens.

With existing systems, rainwater flows across roadways and footpaths which are made of water impermeable material, to flow into gutters through gratings into underground impervious piping. As is obvious the run off carries rubbish through the gratings into the piping. Usual the piping connects with larger diameter piping or open stormwater or drainage channels.

Existing open stormwater channels and underground pipings are usually constructed to carry the excess run off to a large body of water such as a lake or the sea. The concrete walls of the conventional open drainage channel is open allowing the entrance of natural organic waste such as leaves, bodies of animals and soil as well as man generated wastes such as plastics. This material is collected along the entire length of the drain as is deposited in the river system or finally the sea.

Because of the high concentration of organic material, oxygen is depleted 10 from this water and this together with the entrained silt and other pollutants, degrade our river systems.

As the concrete walls and the impervious piping are substantially impervious to water, water is carried away from the environment which it enters the channel with 15 minimal opportunity of water entering the immediate ground water.

Further these open channels accumulate litter and silt, as well as stagnant pools of water which are ideal breeding grounds for mosquitoes, rats and other vermin. And disease. Large and deep open stormwater channels also are a danger for small children and animals and potential hazard for vehicular traffic.

Even in the case of an enclosed drainage system utilizing underground pipes, silt, rubbish and pollutants are swept into the pipes via gutter collection points such as drains and the oxygen content of the water is lowered and entrained pollutants are

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again flushed into the river systems. The concentration of flow by the conventional drainage systems is a major cause of flooding in low areas of the city.

As illustrated in the drawings, a silt or rubbish collection tank 43 can be utilized to feed run off into a storage/piping system (not shown in the drawings). An impervious container 44 is buried in the ground and has an opening 45 located at its base, communicating with a filter pipe 50 which has two opposed planar walls having apertures 28 and load bearing sections 29. The apertures 28 of one wall are out of registry with the apertures of the opposed wall. The filter pipe 50 is wrapped in a 10 geotextile material 9.

*oo* Lining the base and the wall of the container 44 are modules of drainage cells.

,etc%° A geotextile bag 46 sits within the container 44 and its open end 47 is connected to an •inlet pipe 48.

Runoff containing silt and rubbish will flow into the bag 46 through the inlet :p pipe 48 where the silt and the rubbish will be retained and the filtered water will flow through the drainage cells 49 through the opening 45 into the filter pipe 50. As illustrated in Figure 3, the filter pipe 45 which will lead into the storage/piping system could be made of discrete pipe sections.

The present invention provided a drainage collection system which retains and filters rainwater for-eventual discharge into a known type of storage/piping system.

',r It will be apparent that modifications or alterations could be made to the preferred form of the invention as described above without departing from the spirit or scope of the present invention as defined in the appended claims.

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Claims

1. A silt trap comprising a water impervious container having an opening in its base; a layer of perforated modular wall panels, lining the inner walls and the base of the container and defining a passageway in communication with the said opening in the base of the container; 10 a bag of water permeable geotextile supported on the modular wall panels; and an inlet pipe connected to said bag, such that solids, carried by water into said bag, are retained in said bag and the filtered water passes along the passageway defined by the modular wall panels and out through the opening in the base of the container.

2. The silt trap according to claim 1, wherein the perforated modular wall panels comprise two planar spaced apart perforated surfaces with a plurality of rigid spacer members therebetween, maintaining said surfaces in a fixed spaced relationship with each other.

3. The silt trap according to claim 1 or 2, wherein the opening in the base of the container is connected to piping formed by the said modular wall panels connected end of end and wrapped in geotextile.

4. The silt trap as claimed in any one of claims 1 to 3, wherein the container has a removable water impervious lid to allow the bag of water permeable textile to be removed. A silt trap substantially as herein described with reference to the accompanying drawings. C C C.