Abstract:
A method and system for treating stormwater runoff containing impurities includes collecting the runoff in a basin and allowing the runoff to settle in the basin for a predetermined time before allowing the filtration step to be initiated. The time delay is controlled by a controller sensitive rain fall, turbidity, or other variables selected by the user. During the filtration step a separator member is positioned floatingly between a filter element and impurities floating on the surface of the unfiltered water.

Description:
The present invention is a divisional application of U.S. patent application Ser. No. 09/157,866, filed Sep. 21, 1998, now U.S. Pat. No. 6,077,423, which claims the benefit of U.S. Provisional application Ser. No. 60/059,492, filed Sep. 22, 1997. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to stormwater sedimentation, separation, filtration and treatment systems and a method of stormwater sedimentation, separation, filtration and treatment. More specifically the present invention relates to an above grade canister type filtration system utilizing replaceable filter cartridges within the canisters combined with an electronic control system and automatic valve, a floating separation device, an a method of filtering stormwater runoff from developed areas. 
     In recent years, many local state and federal regulations have required installation of stormwater abatement systems to achieve filtration of stormwater runoff prior to exiting development projects. Many developments are required to construct and maintain stormwater sedimentation and filtration basins with each basin having a particular configuration to match the particular development project. However, existing basins have been constructed with the primary purpose of capturing and filtering prior to the release of a certain quantity of stormwater runoff from the development project. The majority of the current stormwater filtration sedimentation basins utilize a sand filter bed usually eighteen inches or more in depth overlying along or beneath the grade perforated polyvinyl chloride (PVC) pipe or the like. This current method is designed to cause the stormwater captured in the basin to be drained by gravity through the sand bed causing filtration of the water prior to entering the PVC drain pipes beneath the sand filtration media. 
     The current technology utilized in existing sedimentation and filtration basins has a variety of problems. The primary problems associated with the current technology are that small particulate matter in the stormwater settles to the bottom of the filtration basin causing a blinding and clogging of the filter media (i.e., sand), unacceptable draw-down, point discharging, water stagnation, and increased bypass potential. To overcome these problems the party responsible for maintaining the stormwater filtration system must incur enormous costs in regrading, raking, and often times replacing the filter media (i.e., sand, or diatomaceous earth, etc.) after each rainfall event. 
     A further problem is the large amount of land required for construction of a sedimentation basin and a separate filtration basin used in combination for stormwater control. By combining the sedimentation and filtration processes within the same basin, the amount of land needed for the entire stormwater filtration system (basins, etc.) is dramatically reduced affording the developer additional developmental land or reducing the overall land required to be purchased for a development project. 
     Yet a further problem is the disposal of large quantities of filter material (i.e., sand, diatomaceous earth, etc.) during maintenance. When the filter media becomes contaminated, polluted or otherwise inefficient or ineffective, the filter media has to be physically removed and transported for disposal drastically increases the cost of maintenance. Additionally, with current technology a responsible party cannot perform maintenance on or dispose or replace filtration media at times when the media has become clogged or blinded and the basin above the media is full of stormwater runoff. The present invention provides for a contained cartridge type filtration system which can be installed above grade in a horizontal or vertical position which will allow gravity filtration of stormwater at appropriate times through canister filtration systems utilizing filter media which can be easily removed and disposed in on-site disposal containers or through other appropriate means. It provides a filtration system which allows for filter media replacement with water standing in the filtration and sedimentation basins without causing the risk of release of contaminated stormwater. 
     Although there have been devices that either filter stormwater or devices that cause the shut off of stormwater flow upon the sensing of pollution, the present invention utilizes a distinct and unique technology involving a process and mechanism of combined sedimentation, separation and filtration. Automated sensing and logic components provide filtration at an optimum level; together with a mechanism to prevent water flow until maximum filtration and maximum sedimentation have been achieved. This multi-function device and process is distinguishable from the prior art with respect to both the filtration of stormwater as well as the shut off of stormwater flow upon sensing pollutants. While existing devices provide for a removable filtration medium, they all have a common element of being at or below grade. The present invention provides an above grade filtration canister system, not activated until maximum sedimentation and separation has occurred, and filtration of the “first flush” of runoff water having the heaviest concentration of pollutant loadings. The runoff which occurs after the “first flush” has been captured is diverted into the stormwater sewer system. The entire “first flush” runoff contemplated in this process is contained in a basin to allow maximum filtration, separation and sedimentation prior to it being treated through the filters with subsequent release through automatic shut off valve into a collecting stormwater sewer system or receiving stream. 
     SUMMARY OF THE INVENTION 
     An above basin grade stormwater separation and filtration system comprising a plurality of filtration canisters containing replaceable filter media or cartridges plumbed to a common drain pipe is controlled by an automated shut-off valve activatable by an electronic controller. This allows filtration and separation of stormwater to begin after sedimentation has occurred over a specified period of time and/or when the turbidity of stormwater being held for filtration has been reduced to a specified level. The electronic controller is capable of monitoring environmental conditions and the conditions of the stormwater being held for filtration. The controller opens and closes the automated shut-off valve as necessary to allow separation and filtration at optimum times. The above grade separation and filtration canisters do not blind or clog as a result of sedimentation because they are installed above grade in a variety of configurations. The basin of the present invention may be poured in place on the development site or be a precast rectangular concrete unit with required plumbing and valving systems for use where a precast unit is more economical or desirable. 
     The sediment build ups in the combined sedimentation filtration basin of the present invention are removed following a periodic maintenance schedule without any detrimental effect to the filtration capabilities. Separation of hydrocarbons and other floating pollutants accumulated at the surface level of the contained water is achieved by use of a circular floating separation member on the filtration canister. This separation efficiency is enhanced by allowing the separator member to float along the filtration canister length as the basin water level drops during filtration or rises due to additional rain fall. The above grade filtration system may be constructed as part of a new development or retrofitted to existing sedimentation and filtration basins. 
     The present invention provides (a) an efficient method of stormwater, sedimentation, separation and filtration without the need for separate sedimentation and filtration separation basins and the maintenance and labor costs associated with maintaining the removing of a large area of filter media; (b) a filtration method that employs self-contained filtration cartridges that can be removed and cleaned or disposed of in a cost effective and efficient manner; (c) a method of stormwater filtration and separation which meets local, state and federal requirements in a manner that requires the acquisition and utilization of the least amount of property in association with development projects, reducing the overall costs of the development; and (d) an access area for maintenance allowing use of the surface area over the basin for parking or other development. 
     Additional advantages and uses will be apparent from the description provided herein for those familiar with the relevant art. The foregoing advantages are achieved in an above grade stormwater separation and filtration system utilizing a single basin for separation, sedimentation and filtration employing one or more filtration canisters and separator devices tied to a common drain pipe controlled by an automated shut-off valve activated by an electronic controller box in accordance with the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and together with the description serve to explain the principles of the invention. In the drawings: 
     FIG. 1 is a partial, cut-away perspective and isometric view of the above basin grade filtration chamber showing a series of filter canisters plumbed to a common drain pipe controlled by an automated shut-off valve that is activated by an electronic controller using input from a number of sensors, including but not limited to, a turbidity meter, timers, and precipitation sensors, in accordance with this disclosure. 
     FIG. 2 is a perspective view of the filtration canister that is utilized in the overall filtration system in accordance with this disclosure. 
     FIG. 3 is a cross section view of the cut off valve used to control the flow of stormwater before and during filtration. 
     FIG. 4 is a cut-away perspective of the typical controller box and related components. 
     FIG. 5 is a cross section of the internal arrangement of the filtration canister depicting the filter cartridge and spring locking and sealing mechanisms in the canister cap. 
     FIG. 6 is a cross section view of the turbidity sensor. 
     FIG. 7 is a cut away view of the separator ring that is positioned around the filtration canister depicting the direction of motion of the separator ring in relation to the filtration canister. 
     FIG. 8 is a circuit diagram of the logic board that monitors environmental conditions and activates and stops filtration accordingly. 
     FIG. 9 is a perspective and isometric view of the stormwater separation, sedimentation and filtration device embodied in the present invention shown in an alternate preferred embodiment utilizing a preplumbed, precast concrete rectangular basin unit. 
     FIG. 10 illustrates separate collection and filtration chambers in a single basin. 
     FIG. 11 illustrates a detailed view of the filtration chamber of the embodiment of FIG.  10 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In situations where there is a need, due to stormwater regulations or otherwise, to treat stormwater running off paved or impervious surfaces, the present invention as illustrated in FIG. 1 provides an apparatus and method of treatment that includes separation, sedimentation and filtration of polluted storm water. The invention can be applied to existing sedimentation and filtration basins by retrofitting the existing filtering system which may be less efficient and more expensive to maintain. Additionally, the present invention can be applied to new construction allowing developments to reduce the area required for the treatment basin in addition to obtaining more efficient treatment and decreased maintenance costs. Further, the invention can be applied to new construction through use of a module precast and preplumbed concrete chamber containing the preferred embodiment of the filtration system. 
     In the preferred embodiment of the invention as shown in FIG. 1, a concrete basin  160  is used to capture the first flush of runoff (i.e., ½″, ¾″ etc.) from the impervious area in a real estate development that contains the majority of all pollutants that have accumulated on the impervious surface since the last rainfall event. In the preferred embodiment of the invention as applied to existing basins, the separation portion of the basin  150  is no longer required, as separation takes place in the filtration basin  160  by means of the floating separator device  700 . This allows an increase in total capture volume for first flush filtration due to the fact that he separation chamber becomes a holding chamber  150  for ultimate separation, sedimentation and filtration. 
     When a rainfall event begins, the rain sensor  815  is activated which causes the digital controller to activate the shut off valve  300  to prevent stormwater from being discharged into the stormwater drainage until time has passed to allow for sedimentation to occur. As stormwater fills the basin the floating separator devices  700  rise around the filter canisters  200  to prevent pollutants on the water surface (oils, hydrocarbons, floating matter, etc.) from coming in contact with the filter canisters  200 . If the water level in the basin rises above the top of the filter canister  200  the separation device  700  is held in place by bouancy at the top of the filter canister  200  by striking the rim of the cap  202  that is attached to the top of the canister unit  200 . Once the basin has reached capacity, additional cleaner runoff is routed to the storm sewer bypassing the basin by use of a weir  191  or other suitable means. 
     After the rain sensor  815  activates the digital controller FIG.  8  and closes the shut off valve  300 , a digital timer is tripped after the rainfall event stops to allow a preset amount of time to pass thereby allowing sedimentation to occur before the filtering process begins. After the present time has passed, the digital controller  413  opens the control valve  300  (if the optional turbidity sensor  600  is used, the control unit  400  verifies the clarity of the water before opening the control valve  300 ). 
     After the control valve  300  is opened, the stormwater is allowed to begin filtering through the filter canisters  200 . As the water level  170  in the basin drops, the separator devices  700  descent down the outside of the filter canisters  200  maintaining a physical barrier between the floating pollutants on water surface  170  and the filter canister  200 . The stormwater entering the filter canister  200  passes through the filter cartridge  505  (FIG. 5) and into the drain pipe  120  which conveys the filtered stormwater through the open valve  300  to the storm sewer or receiving stream  195 . 
     In the event the rain sensor  815  detects rainfall during the filtration cycle, or the turbidity sensor  600  detects turbidity in excess of a preset level, the digital controller  413  activates the compressor  408  (FIG. 4) and closes the flow valve  300 . The filtration cycle is allowed to resume after additional time has passed to allow reduction of the turbidity. 
     In the preferred embodiment of the filter canister  200  as depicted in FIG. 2, the canister  200  is a cylinder  201  made of PVC or other suitable material that is sized larger than the diameter of the filter cartridge  505  to be used. Atop the cylinder  201  is a cap  202  that is designed to fit snugly around the outside surface of cylinder  201  eliminating bypass potential. In the preferred embodiment, a multiplicity of large inlet ports or holes  203  provide an opening for water to pass from outside cylinder  201  to the area between the filter cartridge  505  and the wall of the cylinder  503  as depicted in FIG.  5 . The cylinder  201  as depicted in FIG. 2 is seated in the base  204 . Base  204  is used to reduce the diameter of the cylinder  201  portion of the filter canister. Base  204  is equipped with a fastening mechanism  205 , which in the preferred embodiment is a threaded pipe section. The cylinder  201  portion of the filter canister as depicted in FIG. 2 is covered in an external filter media such as a metal or fabric mesh or screen  206  that me be spaced away from the outer wall of cylinder  201  by means of a spacer ring  207  made of rubber or other suitable alternative material. 
     As depicted in FIG. 1, the fastener  205  is plumbed into a pipe adapter  218  that connects to the common drain line  120 . The stormwater passing though the filter canister  200  is piped by the common drain line  120  to the control valve  300 . Control valve  300 , as depicted in FIG. 3 consists of a pneumatic bladder  307  that is non-fouling and can be inserted into any straight section of pipe that is at least 24″ long with little or no plumbing modification being required for installation. The bladder  307  may be inflated with compressed air from the compressor  408  to cut off water flow from drain line  120  and deflated to allow flow to continue as filtration occurs. Air used to inflate or deflate the valve is conveyed using an air hose  409  that passes through a seal  302  located in the cap  303  of the control valve section  300  of the drain line. The pneumatic bladder  307  is attached to the air line  409  by means of a secure air tight connector  306 . 
     The control unit  400  is comprised of a control box  401  with a water tight lid as depicted in FIG.  4 . In the preferred embodiment of the invention the control box  401  and lid are made of rigid water proof plastic material. The control box contains a 12 volt power supply (battery)  801 , a digital controller board  413  mounted on the panel  402  by fasteners  414 , an air compressor  408 , an air release valve  407 , a pressure sensor  406 , and other components required to monitor and provide automatic operation of the filter process. 
     The air supply line  409  leaving the controller box  401  provides air to the pneumatic control valve  300  that is depicted in FIG.  3 . When conditions exist that cause the circuit board component  413  of the electronic controller (more detailed description provided below) to activate the air compressor  408 , air is forced through the supply line  409  into the bladder portion  307  of the control valve  300  until such time as the bladder portion  307  of the control valve  300  inflates to a position which seals the bladder  307  in a position against the inner diameter of the control valve section of PVC pipe  304 . After the bladder  307  has reached its inflated position against the inner wall of the pipe  307  the pressure switch  406  sends a signal to the logic board  413  to discontinue operation of the compressor  408 . After the bladder valve  307  has been fully pressurized, the logic board  413  continues to monitor the pressure in the inflated bladder  307  by use of the information obtained through the analog pressure switch  406  that is supplied to the controller logic board  413 . In the event the bladder pressure decreases, the logic board  413  activates the compressor  408  to send an increased volume of air through supply line  409  to maintain the inflated position of the bladder  307 . 
     FIG. 3 depicts a cross section of the control valve pipe  300  depicting the air supply hose  409  coming from the controller box  400  through the water tight seal  302  located in the top of the cap  303 . The air supply hose  409  is securely fastened by the seal  302  to prevent slippage of the portion of the line  305  located within the section of pipe containing the valve apparatus. The secured portion of the air hose  305  is fastened to the bladder  307  by use of a durable air tight fastener  306  that prevents the bladder  307  from traveling down stream within the drain pipe  120  when the bladder  307  is in its deflated and open valve position. 
     FIG. 4 depicts the various primary components located within the controller box  401  as originally designed for the preferred embodiment. A water tight connector  410  is fastened into the bottom of the controller box  401  to allow for passage of the wiring from the turbidity meter  600 , the rain sensor  815  and the solar panel  80  into the controller box  401 . The electronic components within the controller box  401  are mounted onto a removable service panel  402 . The components include the air compressor and motor  408 , the pressure release valve  407 , the pressure switch  406 , the cross adapter  405  and the check valve  404 . Check valve  404  prevents the loss of air from the inflated bladder  307  feeding back throughout air compressor  408 . A terminal bus  403  is utilized for making connections to the various sensors and the logic board  413 . A 12 volt electric power supply (battery)  801  sits on the inner floor of the controller box  401  and is fastened to the removable service panel  402  by means of a bracket  411 . 
     FIG. 5 is the internal configuration of a filter canister  500  (or  200  in FIG. 1) of the present invention. Cylinder  503  is provided with inlet ports  504  which allows unfiltered water to enter the inside  501  of the canister. An internal filter media cartridge  505  is held within the canister under spring tension as spring  509  urges against collar  510  which in turn presses against the filter media  505  of hollow filter cartridge  505 . The spring  509  and the collar are centered by pin  513  which is attached to cap  502 . 
     Cap  502  is thusly spring loaded. By pulling clip  508  out of the side of the cap  502 , the cap is easily released from the cylinder  503 . The clip, as seen in FIG. 5, extends through small holes in the cap and the cylinder. Spacer  507  enables the user to easily grasp the clip  508 . 
     Water passes through the filter media  505  into the hollow discharge channel  506  and out an outlet (similar to outlet  213  shown in FIG. 2) into the drain pipe  120  as is well known in the filtering art. Cartridge  505  is replaceable by removing cap  502  and lifting the cartridge  505  from the cylinder  503 . While the canister  500  of FIG. 5 is shown without an external filter screen as shown in FIG. 2, it should be understood that canister  500  may be equipped with such a screen. 
     FIG. 7 illustrates the separator member  700  positioned floatingly between the canister input port  203  and impurities  706  (oil) and  704  (particulate). As the level of the water surface  707  rises and falls, separator  700  rises or falls accordingly. The space  705  between the outer wall of the canister  200  or the external filter media  206  (FIG. 2) and the inner wall of the separator is sufficient to allow for a non-binding slippage along the length of the canister, but not sufficient to allow larger particulate (about 0.1″ diameter) floating on the water surface to enter the ports  203 . 
     Separator  700  has a flanged shoulder  701  and a downwardly depending collar  709 . The shoulder  701  keeps floating particulate away from the canister. Collar  709  is provided with a multiplicity of openings  702  on the end opposite the shoulder  701 . When the openings  702  align with the inlet ports  203  in the canister, unfiltered water is allowed to enter the canisters for filtration. 
     Canister  200  is further provided with a removable cap  202  which enables the user to remove the filter media inside the canister. A quick release clip  209  is attached through the cap  202  as discussed above with canister  500 . The release enables the user to easily remove the cap  202  and remove the entire filter-cartridge as necessary. 
     FIG. 8 is a schematic drawing of the logic control board  413  and related components thereon. Electronically, the 12 volt DC solar panel  800  is used to maintain a charge in the battery units  801  so that unit is independent of external power. The 12 volt DC battery  801  provides 4.5 amp hour capacity to power the unit for extended periods of time without any solar power. The preferred embodiment of this unit will operate approximately 30 days during several rainfall events without the 12 volt DC battery  801  being provided with additional charge from the solar panel unit  800 . A negative − (common voltage  802 ) is supplied to the logic control board  413  and all peripherals on a constant basis. A relay contact  803  (normally closed position) provides power to the air solenoid coil  804 . The air solenoid valve  407  is a normally closed solenoid type valve that maintains air pressure in the bladder  307  at a constant level when the bladder is used in its inflated position  307 . A solid state switch  805  is utilized to energize the air solenoid coil  804  for an approximate 10 second duration controlled by the digital timer  835  through the timer control line  837  to deflate the bladder  307 , thereby opening the control valve  300 . An LED indicator light  806  is used to indicate that the air solenoid is energized allowing the user to know that the air bladder  307  is being deflated. A relay contact  807  is used to activate the air compressor motor  808  when the relay coil  828  that operates contacts  803  and  807  is made to be in its closed position. The air compressor motor  808  provides compressed air upon demand in various durations when activated by the relay  828 . A power diode  809  is utilized to prevent damage to the digital logic control board in the event the battery polarity is inadvertently reversed. A (+) plus voltage feed  810  is provided to the digital logic control board. A user is informed that the (+) plus voltage  810  to the logic control board has been activated by use of an LED indicator light  811  to indicate that the voltage is present. A standard rain sensor circuit  812  is utilized to detect the presence of rain depending upon the status of the contacts located in the rain sensor  815 . The rain sensor circuit  812  detects the presence of rain and starts the sequence of events relevant to filtration by powering the digital logic control board  413  through solid state logic switch  819 , starting the air compressor motor  808  to inflate the bladder valve  307  and preventing the starting of the long duration (i.e., 20 hours, 30 hours, or the like) timer  832  that maintains the pressure in the bladder  307  by inhibiting the air release solenoid valve  407  until the rain stops. Any reoccurrence of rain event during the preset timing duration resets the timer  832  by removing the power provided to the solid state logic switch  825  to the timer. An LED indicator light  813  is used to indicate to the user that the rain sensor circuit  812  from the rain sensor probe contacts  815 . The rain sensor probe contacts  815  are made of non-corroding stainless steel to provide fail-safe operation. The rain sensor output line  816  from rain sensor circuit  812  leads to a flip/flop one  817 . A logic high when rain is detected by the rain sensor probe contacts  815  and a logic low when no rain is present and the sensor probe contacts  815  are open. The flip/flop one  817  is used on the digital logic control board  413  to activate the solid state logic switch  819  that activates and maintains power to flip/flop  824  and timers  832  and  835 . 
     A push button switch (momentary normally open)  818  is used to simulate rain to start the sequence of events produced by the digital logic control board in order to manually activate the control board for testing or other relevant purposes. The solid state logic switch  819  controlled by flip/flop one  817  is fed by output line  820  between flip/flop one  817  and the solid state logic switch  819 . A push button switch (momentary normally open)  821  is utilized to reset the logic to the standby or resting state within the logic system. Logic switch  818  provides a switched plus voltage circuit  822  to power flip/flop two  824 , the LED indicator light  823  indicating that the solid state logic switch  819  is active, and solid state logic switch  825 . The flip/flop two on the digital logic board that is fed from the switched plus voltage  822  activates relay  828  through the pressure switch normally closed contact  827 . The activated relay contact  807  closes causing the air compressor motor  808  to begin operation which inflates the bladder  307  to a predetermined pressure. When the predetermined pressure is reached, the pressure switch contact  827  opens and deactivates relay  828  which opens contact  807 , shutting off the air compressor motor  808 . If the pressure in the bladder  307  falls off, the pressure switch contact  827  will close and activate relay  828 , closing contact  807  which will start the air compressor motor  808  to reinflate the bladder  307 . When the pressure switch  827  is activated with the bladder pressure, the normally open contact  829  will close and activate indicator  830  which indicates the bladder valve  300  is in the closed position preventing stormwater from flowing through the drain pipe  120  to the discharge side of the pipe  195  (FIG.  1 ). 
     Solid state logic switch  825  is activated by voltage from solid state logic switch  819  in logic low (rain has ceased) from the rain sensor circuit  812 . The solid state logic switch  825  provides power to the timing circuits  832  and  835 . An output line  826  is used from the digital long term timer  832  to reset flip/flop two  824  at the end of the long duration (i.e., 20 hours, 30 hours, or the like) time period and to start the solid state 10 second timer  835 . The resetting of flip/flop two  824  prevents the air compressor motor  808  from starting when the pressure is lost in the bladder valve  307 . The timer  835  activates the solid state logic switch  805  which, in turn, activates the air solenoid coil  804  for a 10 second period through the normally closed relay contact  803 . The activated open air solenoid deflates the bladder  307  in the bladder valve  300  and allows water to flow through the filter canisters  200 , drain pipe  120  then exiting drain pipe  195 . The pressure switch contact  827  is a normally closed contact, and the relay coil  828  operates contact  803  and  807 . The pressure switch contact  829  is a normally open contact switch. When the bladder valve  300  is closed the LED indicator  830  is used to indicate the bladder is in its closed or pressurized condition. Timers  832  and  835  are activated by solid state logic switch  825  through the switched (+) plus voltage  831  that runs from solid state logic switch  825  to timers  832  and  835 . The primary timer  832  is a digital long term timer on the logic control board  413  consisting of a solid state oscillator and a digital divider to produce an output  826  20 hours after being actuated. The output  826  resets flip/flop two  824  and starts solid state air solenoid timer  835 . The period (time per cycle) of the oscillator is controlled by the timing resistor  834 . An LED indicator  833  is used to indicate the period of the oscillator in timer  832 . A timing resistor  834  is present for the oscillator in timer  832 . 
     A solid state timer  835  is started by the output line from the digital long term timer  832  and times the energized time of the air solenoid coil  804  by activating solid state logic switch  805  through output line  837 . A timing resistor  836  is provided for the solid state timer  835 . Solid state logic switch  805  is activated using the output line  837  from solid state timer  835 . When the output line  837  activates solid state logic switch  805  it also resets flip/flop one  817  which returns the digital logic controller to its resetting state and low current consumption. 
     FIG. 6 depicts a cross section of the turbidity meter (option) that would utilize a light emitting diode  601  and a receiver  604  to determine the level of particulate matter contained in the stormwater that would flow between the open space between the receiver and the light emitting diode. When used, the supply lines  603  to the light emitting diode and the lines forming the circuit in the sensor would be tied to the appropriate component on the logic board  413  and would travel between the logic board and the turbidity meter  606  through the water tight connector  410  at the bottom of the controller box  401 . The structural component of the turbidity meter  606  is made up of a PVC tee  705  inserted into a larger diameter PVC pipe  602  which has been beveled to allow for placement of the sensor  604  and light emitting diode  601 . 
     Picture of FIG. 9 depicts an embodiment of the filtration, sedimentation and separation processing device with the controller box  400  and solar panel  800  and rain sensor  815  (not shown) constructed with a precast concrete structure  900  that contains a drain pipe  120  that is preplumbed beneath the floor of the concrete structure  900  passing through and on either side of support beams  910  that run the length of the concrete structure  900  to provide a space beneath the structure  900  for placement of the drain pipe  120  plumbing field. In this depiction of the preferred embodiment, the filter canisters  200  and related separator devices  700  are mounted in a compact arrangement through the floor of the concrete structure  900  into preset threaded inlets  920  that are evenly spaced throughout the floor of the structure  930 . When using the embodiment of FIG. 9, sealing plugs  940  are placed into the preplumbed threaded inlets  920  depending upon the number of filter canisters  200  that are desired to be used based on the spacing of the receiving watershed area. One advantage of the embodiment contained in a precast concrete structure  900  is that the precast structure is a module unit that can be constructed off site and dropped in place. Additionally, the precast units can be plumbed so that there are slip joints on the back end of the precast unit at location  950  so that several modular units could be placed in line with one joining the other using the slip joints  950  at the back end and front end of the middle modular units. The end modular units  900  would require an elbow and teed plumbing connection on the main drain line  120  to loop the line among the several drain pipes in drainage field located on the floor of the structure. The first module unit  900  in the series (when more than one is used) would contain the controller valve  300  and the control box  400  and other related apparatus. The use of this embodiment will allow off site construction of several modular units that could be precast off site and dropped in place very efficiently to either accept first flush flows directly from the surface area from which stormwater is to be treated or could be used as a single or multi modular filter unit system receiving flow from an additional rough cut basin in which water is stored and collected and then fed via a pipe inlet into the precast modular filtration unit(s) as depicted in FIG.  9 . Whether installed in a cast in place basin or a precast unit, grates or lids can be used, if desired, to cover and enclose the basin to allow use of the surface area above the basin for parking or other development. 
     EXAMPLES 
     The following examples describe the manner and process of using the present invention and sets forth the best mode contemplated by the inventors of carrying out the invention, but is not to be confused as limiting the scope thereof. 
     Example 1 
     A combination above grade automatic stormwater separation and filtration system and method of separation of filtration is utilized at the low end of a parking low of a real estate development. The system is plumbed into a pour in place basin that is designed to hold a capacity of ½″ to 1″ of the initial stormwater runoff (first flush) leaving the paved service. A weir or bern is put in place so that after the basin has reached its first flush capacity the remainder of the stormwater, which should be much cleaner due to the washing off of pollutants in the first flush, is diverted directly into the storm sewer or collection system. After the preset amount of time has occurred from the beginning of the rainfall event that caused the stormwater run off, the bladder valve would open allowing the filter cartridges contained within the filter canisters to begin filtration. During time of filtration, after sedimentation had occurred, the separator devices would continue to separate free floating pollutants such as oils and floating particulate matter, located on the surface of the water in the basin from coming in contact with the filter cartridge or filter canister units. This separation insures that chemicals and other floating pollutants or materials do not decrease from the efficiency of the filtration process provided by this invention. 
     Example 2 
     An existing stormwater basin providing sedimentation, filtration and separation for a development that utilizes a sand, diatomaceous earth or other type of high maintenance filter medium that is subject to clogging due to sedimentation, is retrofitted by removal of the filtration medium (i.e., sand etc.) and installation of the collection lines and above grade automatic stormwater separation filtration system and method of separation and filtration. The automated shut off valve is plumbed into the portion of the main drain line closest to the headwall of the existing basin that contains the drain pipe to the stormwater sewer collection system or receiving stream. The basin is then backfilled with earthen material or preferably, with concrete to cover the PVC drain pipe with at least two inches of cover. Utilization of the present invention in a retrofit situation such as in this example would increase the capacity of the first flush that can be contained in the basin enhancing total filtration capabilities and further protect against stormwater pollution. Additionally, maintenance becomes much simpler after the retrofit in that the huge bed of filtered material that would ordinarily have to be handled, cleaned, reaked and ultimately disposed of on a regular basis, will have been replaced with efficient cartridge typed filters located in the filter canisters that make up a part of the present invention. These filter cartridges can be removed and recycled, with replacement occurring as often as necessary depending on pollutant loads and rain fall. 
     In both example 1 and 2 above, the current invention would utilize the common element of timing the beginning of the filtration process so that maximum sedimentation could occur, dropping pollutants out of the contained stormwater and maximum separation cold occur layering floating or light pollutants on the top of the water level prior to beginning filtration through opening of the controller valve. As filtration occurs and levels decrease in the basin the pollutants that have sedimented on the bottom of the basin will eventually be merged with the floating pollutants on the water surface after total draining the filtration has occurred. A certain component of evaporation would be figured into the ultimate removal of water from the basin allowing the free floating pollutants (oils, particulate matter) to bond with the sediment in the bottom of the basin resulting in a slowly building sludge material which can be easily periodically cleaned and removed by ordinary maintenance protocol. 
     Yet another embodiment of the present invention may be seen in FIGS. 10 and 11. This embodiment has been demonstrated to prolong the life of the cartridge filter media in certain circumstances. In this embodiment the collection and initial sedimentation of the stormwater runoff takes place in a separate compartment of the basin. Basin  15  has two compartments  17  and  19 . The stormwater runoff is initially collected in catch basin  17 . After a set period of time during which sedimentation of impurities occurs, control valve  300  may be opened in the manner discussed above. Settled, unfiltered runoff enters filtration compartment  19  from catch basin  17 . The location of the discharge port  21  in catch basin  17  may vary depending upon the sedimentation design perimeters. In FIG. 10 the discharge port  21  is positioned in the bottom portion of compartment  17  along divider wall  16 . 
     Opening of valve  300  allows settled, unfiltered runoff water to flow into compartment  19  which is plumbed with above grade filter canisters  200  as shown in FIG.  11 . The canister may be provided with separator rings  700 . The canisters  200  and separators  700  are identical in structure to those described in the other embodiments of this invention. Unfiltered runoff passes through inlet opening  203  and out discharge opening  213  into discharge pipe  120  for further treatment if an as necessary. 
     This invention is used for any situation in which it is desired to filter quantified amounts of stormwater run off. By use of a logic board, automated control valve, together with the unique filtration canisters and method of filtration, stormwater filtration can be performed on an efficient and economic scale. 
     While the preferred embodiments have been fully described and depicted for the purpose of explaining the principles of the present invention, it will be appreciated by those skilled in the art that modification, substitutions and changes may be made due to without departing from the scope of the invention set forth in the appended claims. The embodiments of the invention in which the exclusive property of privileges claimed are defined as follows: 
     Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.