Abstract:
A rainwater collection system is described which includes generally a rainwater routing system and a collection unit. The rainwater routing system may comprise a first flush diversion unit designed to discharge to a run-off path, an initial amount of rainwater such that initial particulate matter from rooftops, etc., are not collected. The rainwater routing system may comprise a pre-treatment unit, the pre-treatment unit designed to remove particulate matter from the rainwater. The collection unit of the rainwater collection system comprises a storage tank having an internal day tank compartment. The described rainwater collection system allows for the collection of rainwater with a substantially reduced amount of particulate matter.

Description:
CROSS-REFERENCE 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/424,426 filed Dec. 17, 2010, the entirety of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This application relates generally to runoff collection systems and, more particularly, to a first flush control arrangement and/or a pretreatment arrangement and/or a storage tank having an internal day tank utilized in connection with a runoff collection system. 
       BACKGROUND 
       [0003]    Runoff collection systems (e.g., rainwater runoff collection systems) have been utilized for years. They are used to capture rainwater runoff and store it for later use. Rainwater collection systems often collect runoff water from building roofs utilizing a gutter and downspout system associated with the building to deliver the water to a collection tank or tanks that may be above or below. ground. Captured water is stored in the tank(s) for later use. One issue with such water collection systems is the need or desire to avoid collecting significant debris and pollutants in the storage tanks. 
       SUMMARY 
       [0004]    In one aspect, a rainwater collection system comprising a first flush diversion unit and a collection unit is provided, where the first flush diversion unit comprises an inlet which feeds water into the unit, a first outlet which directs rainwater to a run-off path, a second outlet which directs rainwater to a collection path, a diversion control device located internally of the unit, and a rainwater gauge, and the collection unit is configured for receiving rainwater from the collection path. The diversion control device has a first position forming a bypass mode and causing incoming water to be directed to the first outlet, and a second position forming a collection mode and causing incoming water to be directed to the second outlet. The position of the diversion control device is controlled by an actuator, the actuator acting in response to the rainwater gauge. 
         [0005]    In another aspect, a rainwater collection system comprising a rainwater routing system, a pre-treatment unit, and a collection unit is provided, where the pre-treatment unit comprises an internal module for treatment, and a housing having an internal space, and comprising an inlet connected to receive rainwater from the rainwater routing system, an outlet which directs rainwater to a collection path, and a removable access lid. The internal module resides within the internal space of the housing. The collection unit is configured for receiving rainwater from the collection path, where rainwater from the rainwater routing system enters the pre-treatment unit via the inlet and is treated by the internal module to remove particulate from the rainwater, and the rainwater exits the pre-treatment unit via the outlet to the collection path. 
         [0006]    In yet another aspect, a rainwater collection system comprising a rainwater routing system, and a collection unit is provided, where the collection unit comprises a storage tank having a first end, a second end, a width, a height, a first compartment, and an internal day tank compartment. The first compartment comprises an inlet, and a weir wall positioned between the first end and the second end of the storage tank and extending across the width of the storage tank, and having an opening governed by a one-way valve. The first compartment and the internal day tank compartment of the storage tank are separated by the weir wall. The internal day tank compartment comprises a pump, which when activated by demand, removes water from the internal day tank compartment of the storage tank via an outlet line, a water level sensor, and a fresh water make-up line which is in operational communication with the water level sensor. Rainwater entering the collection unit via the inlet passes into the first compartment and encounters the weir wall such that the rainwater rises on the inlet-side of the weir wall until the pressure against the one-way valve allows the rainwater to flow through the opening into the internal day tank compartment. Upon an indication from the water level sensor that the water in internal day tank compartment has dropped to a first predetermined level, the fresh water make-up line is opened to deliver fresh water into the internal day tank compartment and the one-way valve prevents such water from entering the first compartment. 
         [0007]    In still another aspect, a method for collecting rainwater is provided. The method comprising (a) directing rainwater to a first flush diversion unit, (b) processing the rainwater from the first flush diversion unit in a pre-treatment unit, and (c) collecting the rainwater from the collection path of the pre-treatment unit in a collection unit. The first flush diversion unit comprises an inlet which feeds water into the unit, a first outlet which directs rainwater to a run-off path, a second outlet which directs rainwater to a collection path, a diversion control device located internally of the unit, and a rainwater gauge. The diversion control device has a first position forming a bypass mode and causing incoming water to be directed to the first outlet, and a second position forming a collection mode and causing incoming water to be directed to the second outlet. The position of the diversion control device is controlled by an actuator, the actuator acting in response to the rainwater gauge. The pre-treatment unit comprises an internal module comprising a screen member, and a housing having an internal space, and comprising an inlet connected to receive rainwater from the rainwater routing system, an outlet which directs rainwater to a collection path, and a removable access lid. The internal module resides within the internal space of the housing. The rainwater from the first flush diversion unit enters the pre-treatment unit via the inlet and thereby, passes through the screen member to remove particulate from the rainwater, and the rainwater exits the pre-treatment unit via the outlet. The collection unit comprises a storage tank having a first end, a second end, a width, a height, a first compartment, and an internal day tank compartment. The first compartment comprises an inlet, and a weir wall positioned between the first end and the second end of the storage tank and extending across the width of the storage tank, and having an opening governed by a one-way valve. The first compartment and the internal day tank compartment of the storage tank are separated by the weir wall. The internal day tank compartment comprises a pump, which when activated by demand, removes water from the internal day tank compartment of the storage tank via an outlet line, a water level sensor, and a fresh water make-up line which is in operational communication with the water level sensor. Rainwater entering the collection unit via the inlet passes into the first compartment and encounters the weir wall such that the rainwater rises on the inlet-side of the weir wall until the pressure against the one-way valve allows the rainwater to flow through the opening into the internal day tank compartment. Upon an indication from the water level sensor that the water in internal day tank compartment has dropped to a first predetermined level, the fresh water make-up line is opened to deliver fresh water into the internal day tank compartment and the one-way valve prevents such water from entering the first compartment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1A  shows a rainwater collection system according to one embodiment of the invention. 
           [0009]      FIG. 1B  shows the rainwater collection system according to  FIG. 1A  in detail. 
           [0010]      FIG. 1C  shows the rainwater collection system according to  FIG. 1B  in detail. 
           [0011]      FIG. 2A  shows a first flush diversion unit according to one embodiment of the invention. 
           [0012]      FIG. 2B  shows an internal view of a first flush diversion unit in a bypass mode. 
           [0013]      FIG. 2C  shows an internal view of a first flush diversion unit in a collection mode. 
           [0014]      FIG. 3A  shows an external view of a pre-treatment unit according to one embodiment of the invention. 
           [0015]      FIG. 3B  shows an expanded view of a pre-treatment unit according to one embodiment of the invention. 
           [0016]      FIG. 3C  shows a schematic of water flow in a pre-treatment unit according to one embodiment of the invention. 
           [0017]      FIG. 3D  shows an internal module of a pre-treatment unit according to one embodiment of the invention. 
           [0018]      FIG. 3E  shows internal features of a housing of a pre-treatment unit according to one embodiment of the invention. 
           [0019]      FIG. 3F  shows an internal module of a pre-treatment unit according to another embodiment of the invention. 
           [0020]      FIG. 4  shows a transverse view of a collection unit according to one embodiment of the invention. 
           [0021]      FIG. 4A  shows a view along line A-A of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Referring to  FIGS. 1A ,  1 B, and  1 C, an exemplary rainwater collection system  10  includes a building downspout  12  (e.g., connected to a roof gutter system), a first flush diversion unit  14  and a pretreatment unit  16  that feed to one or more storage tanks  18 . 
         [0023]    The first flush diversion unit  14  includes an inlet  20  and outlets  22  and  24 . The downspout  12  connects to the inlet  20  to feed water into the unit  14 . Internal of the unit a diversion control device  26  ( FIGS. 2A ,  2 B and  2 C) is located such that in one position (bypass mode ( FIG. 2B )) the device causes or permits incoming water to flow to the outlet  24 , while in another position (collection mode— FIG. 2C )) the device causes or permits water to flow to the outlet  22 . An internal wall  28  of the diversion unit separates the two outlets  22  and  24 . Outlet  22  feeds to a collection path that includes the pretreatment unit  16  and piping  31 , while outlet  24  feeds to a traditional runoff path such as standard downspout piping  27  (e.g., typically a path that does not involve collection of the water for later use). The diversion control device  26  includes an associated actuator  30  (e.g., a pivotally mounted solenoid or motor with associated linear actuator rod  33 ) that is linked to control the position of the device  26 . The actuator may be powered by standard line power or alternatively, by a battery, source of solar power, or any combination of the foregoing. 
         [0024]    In the illustrated embodiment shown in  FIGS. 2B and 2C , the device  26  takes the form of a channel or plate member or flapper  32  that is pivotably moveable between the two positions. In the collection mode position the channel member  32  is moved below the inlet  20  to cause the incoming water to flow over toward the outlet  22 . The diversion control device  26  may be controlled based upon rainfall quantity. Specifically, a rainwater gauge  34  ( FIGS. 1A and 1B ) with associated electronic or electrical control may be used to monitor rainfall and control when the actuator moves the diversion control device from the bypass mode position to the collection mode position. In the illustrated example the rainwater gauge  34  is located above one of the tanks  18  and may detect when the rainwater reaches a specific level or depth (certain number of millimeters etc.), which may be adjustable. Of course, the location of the rainwater gauge could vary. When the specific level is detected, a signal is sent to the actuator  30  (e.g., via wire or wireless) and the actuator responds by moving the device  26 . The device  26  is normally in the bypass mode position and is only moved to the collection mode position after the specific level of rainfall has occurred. After a predetermined amount of time without any rainfall, which may be adjustable, the device  26  resets to the bypass mode position. In this manner, the first flush or initial flow associated with a rain event flows straight through the device from input  20  to output  24  so that leaves, twigs, bird droppings, dead bugs or birds, rodents and other contaminants bypass the rainwater collection system. The cleaner water is then collected in the system for later use and after the rain event the system is reset to prepare for the next rain event. In addition, as shown in  FIG. 2A , the first flush diversion unit  14  includes an access opening  36  that is closed by a removable panel  38  to enable the device  26  to be evaluated if necessary and to facilitate cleaning the interior of the unit. 
         [0025]    As shown in  FIG. 3A , the pretreatment device  16  includes an inlet  40  and an outlet  42 . The inlet is connected to receive flow from the first flush control device output  22 . In the illustrated embodiment shown in expanded view in  FIG. 3B , water entering the device  16  impinges, preferably tangentially or substantially tangentially, upon a curved internal deflector panel  44  and moves downward into a collection space  46  defined by lower screen member  48 . The water must move outward through a lower screen member  48  (e.g., cylindrical in shape) that defines the collection space  46 , as shown in  FIG. 3C . In one example, the screen member may take the form of a continuous deflection screen such as that described in U.S. Pat. No. 5,788,848, which is hereby incorporated by reference herein in its entirety. After moving through the screen the water can then move back upward to exit through the space between the lower screen member and the housing and through outlet  42 . In this manner, incoming debris can be trapped within the collection space to avoid such debris entering the collection tanks  18 . 
         [0026]    Referring to  FIGS. 3B ,  3 D, and  3 E, in one embodiment, the internal structure of the pretreatment device  16  is formed as removable module or unit, including a lower base ring  50  that is diametrically sized to match the internal diameter to the tank or housing  52  of the unit. The periphery of the ring may include one or more slots  54  that are positioned to align with angles or plates  56  that are mounted on the internal surface of the tank  52 . In this manner, proper alignment of the module within the tank  52  is assured. The upper portion of the module also includes diametrically opposed edge trim members  58  and  60  that are sized to engage with the internal surface of the tank wall to help stabilize the module within the tank. The tank includes a removable access lid  62  for cleaning the collection space and/or for removing the module. The collection space may include a solid floor  64  (e.g., internal part of ring  50 ), as shown in  FIG. 3F , so that any collected debris will stay with the module upon its removal, which can then be emptied by simply turning the module upside down. 
         [0027]    An overflow path  33  ( FIG. 1B ) may also be provided from the storage tank  18  back to the traditional runoff path in the event the water flow into the storage tank exceeds the tank capacity. 
         [0028]    While the primary embodiment illustrates use of an above-ground system that receives water from a gutter downspout, it is recognized that the various features of the invention could be implemented in a system in which the storage tank(s), diversion unit and/or pretreatment device are located underground. In addition, although the rainwater collection system shown in  FIG. 1A  utilizes an above ground vertical standing storage tank, it is recognized that a horizontally disposed storage tank can be used, as well as buried storage tanks. Also, while the first flush diversion unit and pretreatment unit of the primary embodiment are, in each case, shown as mounted on a building wall structure, other locations for such units are possible. 
         [0029]    In one implementation, as shown in  FIGS. 4 and 4A , the storage tank includes an internal day tank configuration as follows. Water enters the storage tank  1  through the inlet pipe  2  into a first compartment  66 . In one embodiment, following the inlet pipe  2 , the water encounters a calming inlet, comprising at least one baffle  74  and an overflow compartment  3 . Water is allowed to enter an internal day tank compartment  68  behind (e.g. to the left in  FIG. 4 ) the weir wall  5  through one way valve  6  and opening in the wall  7 . The first compartment  66  and the internal day tank compartment  68  are separated by the weir wall  5 . When water is called for from the tank, a pump  4  located in the internal day tank compartment is powered and level or depth in the tank  1  is reduced by pulling water from the internal day tank compartment  68 . Level sensor  8  will indicate a low water level, and fresh water makeup line  9  is responsively activated (e.g., a valve is opened) to refill internal day tank compartment. The internal day tank compartment  68  fills and one-way valve  6  closes preventing water to traverse weir wall  5  through opening  7  as level of water rises above one way valve  6 . When level sensor  8  indicates that peak refill level of the day tank side of the unit is achieved, the fresh water makeup line  9  is responsively turned off or closed. The remainder of storage tank  1 , e.g. the first compartment  66 , is available for storage of rainwater from next storm event. In one embodiment, the location of the weir wall  5  between a first side  70  and a second side  72  of the storage tank is variable. The amount of fresh water required to fill the internal day tank compartment can be set by appropriate positioning of the weir wall  5  within the storage tank and setting of the fill level triggered by the senor  8  so that a large volume is not needed and so that sufficient space remains in the tank to collect rainwater from the next storm event. Typically, the minimum internal day tank compartment volume (e.g., the amount of fresh water that would be called for if the day tank side of the unit was empty) may be set at between 40 and 100 gallons, though numerous variations are possible. In one embodiment, fresh water can be well or municipal water. 
         [0030]    It is to be clearly understood that the above description is intended by way of illustration and example only and is not intended to be taken by way of limitation. For example, while the primary embodiment contemplates a storage tank formed of a tubular pipe structure (e.g., corrugated metal pipe or some form of plastic pipe such as steel reinforced plastic pipe), other collection unit structures could be used, including concrete or metal plate. Moreover, a collection unit could be formed of multiple interconnected tanks. Other variations are possible.