STORM WATER INTERCEPTOR

Abstract

A storm water interceptor is disclosed. The storm water interceptor comprises an inlet conduit connected to a treatment tank, the inlet conduit for delivering storm water to the treatment tank. Also, the storm water interceptor comprises an aluminum grate located within the treatment tank and below the inlet conduit. The storm water interceptor further comprises an outlet conduit connected to the treatment tank, the outlet conduit extending away from the treatment tank, and having an invert located above the aluminum grate and an orifice located below the aluminum grate.

Claims

1. A storm water interceptor comprising: an inlet conduit connected to a treatment tank, the inlet conduit for delivering storm water to the treatment tank; an aluminum grate located within the treatment tank and below the inlet conduit; and an outlet conduit connected to the treatment tank, the outlet conduit extending away from the treatment tank, and having an invert located above the aluminum grate and an orifice located below the aluminum grate.

2. The storm water interceptor of claim 1, wherein the orifice of the outlet conduit is substantially horizontal.

3. The storm water interceptor of claim 2, wherein the substantially horizontal orifice of the outlet conduit comprises a fixed step.

4. The storm water interceptor of claim 1, wherein the outlet conduit comprises a removable plug.

5. The storm water interceptor of claim 1, wherein the outlet conduit comprises a tee conduit connecting the orifice of the outlet conduit with a portion of the outlet conduit extending away from the treatment tank.

6. The storm water interceptor of claim 1, wherein the aluminum grate includes an access hatch.

7. The storm water interceptor of claim 6, wherein an aluminium lifting chain is affixed to the access hatch.

8. The storm water interceptor of claim 1 comprising an aluminum ladder affixed to an interior wall of the treatment tank.

9. The storm water interceptor of claim 1, wherein the treatment tank is substantially cylindrical and comprises two or more modular sections made of pre-cast concrete.

10. A storm water interceptor comprising: at least two treatment tanks, wherein the at least two treatment tanks comprise a primary treatment tank and a secondary treatment tank; an inlet conduit connected to the primary treatment tank, the inlet conduit for delivering storm water to the primary treatment tank; an aluminum grate located within the primary treatment tank and below the inlet conduit; a connecting conduit connected to the primary treatment tank, the connecting conduit connecting to the secondary treatment tank; and an outlet conduit connected to the secondary treatment tank, the outlet conduit comprising an invert and extending away from the secondary treatment tank.

11. The storm water interceptor of claim 10, wherein the outlet conduit comprises a substantially horizontal orifice, and wherein the invert of the outlet conduit is located above the substantially horizontal orifice of the outlet conduit.

12. The storm water interceptor of claim 10, wherein the invert of the outlet conduit is located below an invert of the input conduit.

13. The storm water interceptor of claim 10, wherein the invert of the outlet conduit is located above an invert of the input conduit.

14. The storm water interceptor of claim 10, wherein the connecting conduit comprises a substantially horizontal orifice at the primary treatment tank and a substantially vertical orifice at the secondary treatment tank, and wherein an invert of the connecting conduit is located above the substantially horizontal orifice of the connecting conduit at the primary treatment tank.

15. The storm water interceptor of claim 10, further comprising an overflow conduit connecting the primary treatment tank and the secondary treatment tank.

16. The storm water interceptor of claim 15, the overflow conduit comprising a substantially horizontal orifice, wherein an invert of the overflow conduit is located above the substantially horizontal orifice of the overflow conduit.

17. The storm water interceptor of claim 10, wherein the aluminum grate includes an access hatch and an aluminium lifting chain is affixed to the access hatch.

18. The storm water interceptor of claim 10 comprising an aluminum ladder affixed to an interior wall of at least one of the primary and secondary treatment tanks.

19. The storm water interceptor of claim 10, wherein the aluminum grate is located above the connecting conduit.

20. The storm water interceptor of claim 10, wherein the aluminum grate is located below an invert of the outlet conduit.

Description

BRIEF DESCRIPTION OF FIGURES

[0034] Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0035] FIG. 1 depicts a cross-sectional view of an embodiment of a treatment tank of a storm water interceptor;

[0036] FIG. 2 depicts an overhead, cross-sectional (A-A) view of the treatment tank of FIG. 1;

[0037] FIG. 3 depicts a view of a component within the treatment tank of FIG. 1;

[0038] FIG. 4 depicts a cross-sectional view of another embodiment depicting treatment tanks of a storm water interceptor; and

[0039] FIG. 5 depicts an overhead, cross-sectional view of the treatment tanks of FIG. 4.

DETAILED DESCRIPTION

[0040] A storm water interceptor for the separation of trash, grit, oil, sediments and/or other debris from storm water is disclosed herein.

[0041] With reference to the embodiment depicted in FIGS. 1-3, a storm water interceptor comprising a treatment tank 21 is provided.

[0042] FIGS. 1 depicts a cross-sectional view of a first exemplary embodiment of the storm water interceptor. The storm water interceptor of FIG. 1 comprising treatment tank 21 provides for the separation of trash, grit, oil, sediments, and/or other debris from storm water runoff.

[0043] The treatment tank 21 is preferably cylindrical or substantially cylindrical in shape. The treatment tank 21 has a cover 27. Depending on site installation requirements, the cover 27 for the treatment tank 25 may be, for example, a solid manhole lid or a catch basin grate. A finish grade for the cover 27 may be set using well known pre-cast moduloc rings varying in thickness from 50 mm to 100 mm.

[0044] The treatment tank 21 may comprise four sections, namely, a flat cap 28 (or transition section), an upper barrel section 29, a middle barrel section 30, and a lower barrel section 31. Alternative embodiments may have a greater or fewer number of sections within a tank. Being part of the treatment tank 21, these sections 28, 29, 30, 31 may be modular in nature. The sections are preferably at least substantially cylindrical and preferably have interior and exterior wall portions. At the lower end of the treatment tank 21 may be a base 32. Each of the four sections 28, 29, 30 and 31, and the base 32, are each preferably made from reinforced pre-cast concrete. Inside treatment tank 21 is a ladder 33 for access by maintenance personnel. Ladder 33 is affixed to the interior walls of sections 29, 30, and/or 31.

[0045] Between sections 28, 29, 30, and/or 31 is preferably a rubber mastic at each joint 40, 39, and 38. The rubber mastic should preferably be heated until it is pliable before joining together any of the various sections 28, 29, 30, 31 of the treatment tank 21. Following such joining, each of the joints 38, 39, 40 are preferably mortared both inside and outside the respective section walls 28, 29, 30, and 31. Such mortaring preferably utilizes sand and Portland cement with an acrylic and polymer admixture to ensure proper bonding. Where possible and available, a flexible waterproof caulking is preferably used instead of mortar.

[0046] Further securing of the various sections 28, 29, 30, and 31 of the treatment tank 21, is preferably accomplished by anchoring frost straps (not shown) vertically to the outside of the treatment tank 21. Preferably, such frost straps would be in the form of a 600-1200 mm75 mm6 mm galvanized plate and would be connected by a inch stainless steel nut and bolt combination that is anchored to some or all of the treatment tank walls of sections 28, 29, 30, and/or 31.

[0047] With respect to base section 32, it preferably has 200 mm-thick reinforced pre-cast concrete that is also preferably made monolithic with section 31. Much like the other modular components of the present invention, base section 32 can be easily lifted and set into place by an excavator or equivalent equipment (not shown). Furthermore, raising or lowering the elevation of the base section 32 and lower barrel section 31 dictates the sump capacity of the treatment tank 21. For example, the taller lower barrel section 31 is, the greater its capacity.

[0048] Connected to treatment tank 21 is an input conduit 50, which permits storm water to enter the treatment tank 21. The input conduit 50 is preferably made of PVC or HDPE piping. From an input orifice 51 of the input conduit 50, storm water is deposited into the treatment tank 21. In the example embodiment of FIG. 1, storm water is deposited into the treatment tank 21 at middle barrel section 30. During installation, the input conduit 50 is preferably pushed into a watertight rubber boot gasket 37 that is securely fitted to a wall of the treatment tank 21. In the example embodiment of FIG. 1, such fitting is to a wall of the middle barrel section 30. Such a connection may be provided by having an opening in the middle barrel section wall 30 drilled or created to the appropriate diameter and elevation to accommodate insertion of a rubber boot that securely fits the outside diameter of the input conduit 50. Also provided is an output conduit 60, and the same manner of fitting it as described above for the input conduit 50 may be provided for output conduit 60.

[0049] The treatment tank 21 preferably has a maintenance platform comprised of a trash grate 68, preferably made of aluminum. Grate 68 may be referred to as a trash rack. Grate 68 acts to separate relatively large debris, such as sticks, rocks, plastic, tin cans and other large debris, from entering the lower barrel section 31, and to minimize blockages of output conduit 60 or adjacent conduits. Storm water passes over and through the aluminum grate 68 as it flows from the inlet orifice 51 of the middle barrel section 30 to the lower barrel section 31. The aluminum grate 68 of the treatment tank 21 may have a hinged access hatch 67, which is connected to a stainless-steel lifting chain 41 that may attach to a ladder rung of the ladder 33. The hatch 67 is preferably 600600 mm in size, which assists with making maintenance more efficient for a vacuum truck to clean the entire bottom of the sump in section 31, as such an opening is unlike a number of conventional treatment tanks that only have enough space for a suction hose and cannot be moved around.

[0050] The location of the aluminum grate 68 results in storm water passing through it, in turn reducing flow velocities, and thereby causing less disturbance of trapped emulsified oil in treatment tank 21.

[0051] Grate 68 is preferably made of aluminum. Aluminum is preferred over conventional alternatives because of its light weight making it easier to lift open for maintenance. Aluminum is also preferred over conventional alternatives because of its efficiency and/or effectiveness in treating storm water present in the treatment tank 21.

[0052] In particular, it is preferable for the grate 68 of the maintenance platform to be constructed of aluminum because of its atomic structure. The free aluminum oxide atoms present in the aluminum causes electrolysis of the free electron in the outer valence layer of an aluminum atom molecule, which may have the effect of changing the polarity of effluent and/or suspended particle molecules. Depending on the polarity between particle molecules, an attraction or repulsion takes place causing suspended solids to coagulate and settle to the bottom of the treatment tank 21.

[0053] With reference to FIGS. 1 and 3, vertical conduit 53 has a lower fixed stepped horizontal lower orifice 52 that increases the distance the effluent must travel inside the treatment tank 21. The orifice 52 is below the input conduit 50 elevation. The length of conduit 53 affects the capacity of treatment tank 21 to retain solids and effluent. A greater retention of solids and effluent results in increased efficiency of the storm water interceptor.

[0054] Vertical conduit 53 forces storm water to move in an upward (vertical) direction, preferably causing suspended solids to settle out into the sump in lower barrel section section 31.

[0055] A tee conduit 58 connects vertical conduit 53 to the outlet conduit 60. Fastened to the upper opening of the tee is a removable plug 55 connected to a handle 56 that lifts to open for maintenance personnel to access the vertical conduit 53 and/or outlet conduit 60 should either become plugged with debris.

[0056] The retention time of treatment tank 21 can be controlled, including increased in duration, in at least two ways (or a combination of both). In a first exemplary embodiment, conduits 53, 58, and 60 have a diameter that is less than the diameter of input conduit 50. In a second exemplary embodiment, the elevation of the invert of outlet conduit 60 is above the elevation of the invert of inlet conduit 50. A greater retention time, preferably in combination with the presence of an aluminum trash gate 68 to increase the contact time between the storm water and the aluminum, is advantageous for improving retention of solids and effluent, which results in increased efficiency of the storm water interceptor.

[0057] With reference to FIGS. 1 and 2, an optional second outlet conduit 70 with orifice 57 can be installed in middle barrel section 30 that leads to a retention field. A 90 degree bend is used so the orifice 57 is substantially horizontal to restrict suspended hydrocarbons from entering the underground retention field.

[0058] A second exemplary embodiment of the present invention involves the use of more than one treatment tank. For example, a primary treatment tank 10 and a secondary treatment tank 12 are shown in FIGS. 4-5, although more than two treatment tanks are also possible. A number of the same components and general principles as with the storm water interceptor having treatment tank 21 as described above may be applied to a storm water interceptor having primary 10 and secondary 12 treatment tanks.

[0059] The treatment tanks 10, 12 are preferably cylindrical or substantially cylindrical in shape. Each tank 10, 12 has a cover 27, 16, respectively. Depending on site installation requirements, the cover 27 for the primary treatment tank 10 is preferably a solid manhole lid as shown or a catch basin grate. The cover 16 for the secondary treatment tank 12 is preferably a solid manhole lid (as shown) to keep large debris from entering the secondary treatment tank. A finish grade for covers 27, 16 may be set using pre-cast moduloc rings varying in thickness from 50 to 100 mm.

[0060] Inside primary treatment tank 10 is preferably four sections, namely, a flat cap 28 (or a transition section), an upper barrel section 29, a middle barrel section 30, and a bottom barrel section 31. However, alternative embodiments may have a greater or fewer number of sections within the primary treatment tank. Being part of the primary treatment tank 10, these modular sections 28, 29, 30, 31 are preferably each made from reinforced pre-cast concrete.

[0061] Inside secondary treatment tank 12 is preferably four sections, namely, a flat cap 24 as shown (or a transition section), a lower barrel section 27, a middle barrel section 26, and a bottom barrel base section 25. Both the primary treatment tank 10 and the secondary treatment tank 12 include a ladder 33, which allows access and egress. The ladder 33 is affixed to the inside of the walls of the primary treatment tank 10 and the secondary treatment tank 12. In one embodiment, the ladder 33 is constructed of aluminum.

[0062] Connecting the middle barrel section 30 of the primary treatment tank 10 with the middle barrel section 26 of the secondary treatment tank 12 is done via a connecting or lower conduit 56, which is preferably made of either PVC or HDPE piping. Such lower conduit 56 may be a straight connection from the primary treatment tank 10 to the secondary treatment tank 12 with no bending. In another embodiment, the lower conduit 56 may have bends ranging from 0 to 90degrees, or alternatively as site specifications may require. For example, there may be cases where there is a need to communicate storm water through the storm water interceptor around a street comer, or between the primary and secondary treatment tanks in a relatively crowded underground urban area.

[0063] The lower conduit 56 has a horizontal lower orifice 57 in the primary treatment tank 10 that permits storm water to enter in an upward (vertical) fashion based on an inverted elbow configuration 58. Storm water must take a 90-degree tum at an inverted elbow 58 then travel horizontally through the lower conduit 56 to the vertical lower orifice 59, in the middle barrel section 26 of the secondary treatment tank 12. The inverted elbow configuration ensures that the horizontal lower orifice 57 is below the invert elevation of the lower conduit 56. As such, the inverted elbow configuration 58 facilitates vertical flow into the lower conduit 56 to ensure suspended hydrocarbons and other lighter than water plastics are trapped in primary treatment tank 10, such as in barrel section 29 or 30 of primary treatment tank 10.

[0064] During installation, it is preferred that conduit 59 is pushed into watertight gaskets 37. This is accomplished by having holes in the walls of barrel section 30 of the primary treatment tank 10 and barrel section 26 of the secondary treatment tank 12 drilled or created according to applicable specifications (e.g., elevation and diameter) to ensure the watertight gaskets fit securely into the barrel section walls.

[0065] Further connecting the primary treatment tank 10 and secondary treatment tank 12 may be an overflow conduit 52, which is preferably made of either PVC or HDPE piping. The overflow conduit 52 allows bypass in case the storm water interceptor is not maintained and the trash grate 68 or the lower conduit 56 become plugged. Additionally or alternatively, the overflow conduit 52 allows bypass in case of a high volume of runoff. Preferably, the overflow conduit 52 has an inverted elbow configuration 55 at its first end at the primary treatment tank 10 such that the overflow conduit 52 has a horizontal overflow orifice 53, and at the secondary treatment tank 12 has a vertical overflow orifice 54. Due to possible backwater effects during full flow conditions of the input conduit 50, the invert elevation of the overflow conduit 52 is above the elevation of the horizontal orifice 53 and should be above (or at least the same as) the obvert elevation of the input conduit 50 (i.e., the obvert is the elevation of the top of input conduit 50). The elevation of the overflow conduit 52 acts as a control of the elevation of retained runoff. In this regard, a relatively higher elevation overflow conduit 52 will allow for a relatively higher elevation of retained runoff. In turn, this effect on elevation of retained runoff has an impact on retention time of retained runoff within the primary treatment tank 10. For example, if the overflow conduit 52 is positioned at a relatively higher elevation, this will generally promote a greater retention time for the retained runoff than the same primary treatment tank 10 that has a relatively lower elevation overflow conduit 52.

[0066] Connected to the secondary treatment tank 12 is an output conduit 60, which permits treated storm water to exit the storm water interceptor. Output conduit 60 is preferably made of PVC or HDPE piping. The output conduit 60 has a horizontal orifice 61 that permits storm water to enter the output conduit 60 in an upward (vertical) fashion based on an inverted elbow configuration 62. The inverted elbow configuration ensures that the horizontal output orifice 61 is located below the invert elevation of the output conduit 60 (i.e., the invert is the elevation of the bottom of the horizontal portion of the output conduit 60), as such a configuration acts to trap suspended oil and facilitates proper functioning of the system. The effectiveness of the secondary treatment tank 12 to separate suspended solids increases as the difference between the invert elevation of conduit 60 and the obvert elevation of conduit 56 becomes greater.

[0067] The elevations of the horizontal lower and output orifices 57 and 61 may vary depending on oil and sump capacity requirements. The degree in which the secondary treatment tank 12 retains emulsified oils further depends upon the elevation of the horizontal output orifice 61, compared to the invert elevation of conduit 60. Performance is increased as the elevation of the horizontal output orifice 61 decreases relative to the invert elevation of outlet conduit 60. Once moving horizontally in the output conduit 60, treated storm water may travel to a body of water such as a lake, river, ocean, or otherwise.

[0068] The vertical distance between the invert elevation of the output conduit 60 and the horizontal orifice 61 determines the capacity in which the secondary treatment tank 12 may hold oils and other petroleum like products. Much like the lower conduit 56, the output conduit 60 is equipped with a 90-degree inverted elbow 62 that limits the amount of oil from escaping the secondary treatment tank 12 during extreme high flow storm events. Preferably, 1.5 meters or greater is maintained between the invert of the horizontal orifice 61 and the bottom sump of base section 25 to prevent blockage from grit and sediment.

[0069] The efficiency of the storm water interceptor increases as the distance between the equilibrium water level (Hw) and the horizontal orifice 61 increases.

[0070] With reference to FIG. 4, the dotted line represents the equilibrium water level (Hw). The equilibrium water level may be determined at least in part by the invert elevation of output conduit 60, and increases depending upon the volume of storm water passing through the storm water interceptor. As shown in FIG. 4, the invert of the outlet conduit 60 may be located below an invert of the input conduit 50. In the alternative (and not shown), the invert of the outlet conduit may be located above an invert of the input conduit.

[0071] With reference to FIG. 5, in one embodiment, the storm water interceptor has a conduit 70 connected to a retention field (not shown). The retention field conduit 70 has a horizontal inlet 90, to prevent trapped oil from entering the retention field.

[0072] With reference to FIGS. 4 and 5, primary treatment tank 10 preferably has a maintenance platform comprised of a trash grate 68, preferably made of aluminum, as well as hatch 67. Additional description regarding grate 68 and hatch 67 is provided above in relation to the description for treatment tank 21.

[0073] It will be apparent to persons skilled in the art that a number of variations and modifications can be made to the storm water interceptor described herein. For example, although specific embodiments are described herein, it will be appreciated that modifications may be made to the embodiments without departing from the scope of the current teachings of the storm water interceptor described herein. For simplicity and clarity of the illustration, elements in the figures are not necessarily to scale, are only schematic and are non-limiting of the elements' structures. It will be apparent to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention, which scope is defined by the claims.