referring now in greater detail to the drawings in which like numerals represent like components throughout several views , fig1 is an exterior , perspective view of a parts washer apparatus ( the “ parts washer ”) 10 , in accordance with an embodiment of the present invention . the parts washer 10 includes a tank 12 and a basin 14 . the basin 14 includes a sink member 16 that defines a basin cavity 18 . the sink member includes a sink ledge 20 around the periphery of the inlet to the basin cavity 18 . a back - splash 22 extends upward from a rear portion of the sink ledge 20 , and a flexible faucet 24 penetrates the rear portion of the sink ledge 20 and terminates in the form of a nozzle 26 . an optional work light ( not shown ) extends upward from the basin and illuminates the basin cavity 18 . the tank 12 includes an optional level indicator 28 and a control panel 30 . the level indicator 28 is depicted as comprising a temperature sensitive , liquid crystal display . the control panel 30 includes an off / on switch 32 , a power indicator light 34 , a low fluid warning light 36 , and a timer switch 38 . this timer switch 38 serves to keep the circulation of the fluid limited to the time when parts are actually being washed . studies of parts washing operators cleaning a variety of parts containing varying amount of soil indicated that a four minute time interval allows the flow to run sufficiently to clean about eight - five percent of all parts . longer flow intervals , if required , are accomplished by reactivating the run switch . fig2 is a cut - away , perspective , exploded view of certain components of the parts washer 10 , in accordance with the present invention . a lower portion of the tank 12 , and components associated therewith , and the faucet 24 are cut - away in fig2 . the tank 12 includes tank walls 42 that define a tank cavity 44 therebetween . the tank 12 further includes a tank lip 46 that extends around the periphery of the inlet to the tank cavity 44 . the sink member 16 includes sink walls 48 extending downward from the sink ledge 20 to a bottom panel 50 that defines a drain hole 52 therethrough . the sink walls 48 and the bottom panel 50 define the basin cavity 18 . the sink walls 48 further define an upper ledge 54 and a lower ledge 56 . each of the ledges 54 , 56 encircle the basin cavity 18 and include four segments that together define a rectangular shape . each edge of a planar , rectangular support grid 58 rests upon a segment of the lower ledge 56 such that the support grid 58 partitions the basin cavity . a rectangular filter pad 60 rests upon and covers the support grid 58 . each edge of a generally planar , rectangular false bottom member 62 rests upon a segment of the upper ledge 54 such that the false bottom member 62 also partitions the basin cavity 18 and is disposed above the support grid 58 . the false bottom member is preferably unitary , defines a drain hole 64 therethrough and includes an upwardly protruding lip around the periphery thereof . a strainer ( not shown ) is defined within the drain hole 64 . a pair of supplemental drain holes 70 are defined through the rear sink walls 48 just above the filter pad 60 . this embodiment comprising the false bottom member 62 , the filter pad 60 , the filter support grid 58 , and drain holes 64 , 52 , 70 , serves to limit evaporative losses caused by the elevated temperature of the cleaning fluid . fig3 is a front , vertical cross - sectional , cut - away view of the parts washer 10 , wherein certain portions of the parts washer are , for explanatory purposes , not cross - sectioned or cut - away . fig3 represents each of the mechanical components ( i . e . the hardware , or “ parts washer ” 10 as herein described ), the fluid component ( represented by a cleaning fluid 72 ), and the biological component ( not seen ) living within the cleaning fluid 72 . as depicted in fig3 the periphery of the false bottom member 62 preferably snugly contacts the sink walls 48 . the tank cavity 44 is preferably partially filled with a cleaning fluid 72 . a submersible pump 73 is disposed within the tank cavity 44 . when pump 73 is operating , it draws the cleaning fluid 72 from the bottom region of the tank cavity 44 and discharges the cleaning fluid 72 into a conduit 74 . the conduit 74 is connected to and discharges into a base ( not shown ) of the faucet 24 , whereby the fluid discharges from the nozzle 26 . the parts washer 10 is preferably further equipped with optional cleaning accessories ( not shown ) such as a fountain brush ( not shown ) that is in fluid communication with the conduit 74 . a heater 76 , that is controlled by a thermostat 75 , selectively heats the cleaning fluid 72 , and the heater 76 is acceptably in the form of an electric heating element that extends from the control panel 30 into the depths of the tank cavity 44 . a level probe monitors the depth of the cleaning fluid 72 , and the level probe is acceptably in the form of a float actuated electric switch 78 that includes a magnet equipped float 80 . a lip 82 extends around the periphery of the sink ledge 20 forward of the back - splash 22 . the lip 82 and back - splash 22 seek to keep cleaning fluid from dripping over the edges of the sink ledge 20 . in accordance with a preferred construction of the present invention , much of the parts washer 10 is acceptably constructed from high density polyethylene . in addition , the sink walls 48 , bottom panel 50 , upper ledge 54 , lower ledge 56 , sink ledge 20 , and back - splash 22 , are preferably formed as a single , molded , unitary piece . optionally , the apparatus may be equipped with a tank 12 containing a pre - treatment compartment . this compartment receives fluid pumped from the bottom region of the tank cavity 44 . by holding this fluid in the proper environment for as long as needed to virtually eliminate oil and grease , this compartment allows discharge of waste into publicly operated treatment facilities . the biological component is preferably in the form of microorganisms that biodegrade organic compounds such as , hydrocarbons , oils , greases , petroleum by - products , creolates , and other carbon based compositions . microorganism which degrade other carbon based compositions such as the long - chain polymers compounds found in structural plastics such as the polyolefins , styrenes , neoprenes , and the like are not suitable if the physical structure of the parts washer or of parts being washed is degradable by the microorganisms . the microorganisms generally convert hydrocarbon compounds and chlorinated solvents into elements of water , carbon dioxide and other digestion products . additionally , the microorganisms are preferably nonpathogenic . suitable microorganisms include those from the genera bacillus , micrococcus , acinetobacter , rhodococcus , nocardia , flavobacterium , saccharomyces , candida and white rot fungus . suitable species are well known and reported in the art . the microorganisms are optionally employed in combination with nitrifying or dinitrifying bacteria , phosphate solubilizing strains of microorganisms , bio - emulsifier producing strains of microorganisms , and strains of microorganisms which produce growth factors such as , b - vitamins . the microorganisms are preferably subjected to a preservation technique in an effort to ensure their viability in the field and their resistance to environmental shock . for example , nutrient and buffer components such as , agar , and water soluble adhesives such as gum are preferably mixed with the microorganisms to promote stability of the microorganisms prior to mixing the microorganisms with a carrier . the carrier is composed of inert and nutrient organic materials that preserve and protect the microorganisms during storage and transportation . suitable microorganisms are available from abs inc . of duluth , ga . as , for example , part number pwm - 25 or from louisiana remediation as lrc - 1 . the filter pad 60 functions as a vehicle for bringing the microorganisms into contact with the cleaning fluid 72 . the filter pad 60 is constructed from cotton , cellulose , polyolefin fibers , polyester fibers , fiberglass , or the like . additionally , the filter pad 60 is constructed from combinations of such components . further , the filter pad 60 is generally a 10 micron filter or larger . microorganisms are attached to the filter pad 60 with an encapsulating agent 84 ( fig4 ) that is water soluble and releases the microorganisms when the cleaning fluid 72 is introduced to the filter pad 60 , as discussed below . an adhesive suitable for this purpose is 3m super 77 adhesive . referring to fig4 which is a perspective , cut - away view of the filter pad in accordance with the present invention , the filter pad 60 includes a layer 86 of inert material , that is disposed below a layer 88 of micron - rated filter media . a suitable inert material is fiberglass . the micron rated material is preferably a material that does not have an affinity for hydrocarbons such as , for example polyester . the microorganisms , the components mixed therewith as discussed above , and the adhering agent 84 are preferably sandwiched between the layers 86 , 88 of the filter pad 60 . a portion of the layer 88 is cut - away for explanatory purposes in fig4 such that the adhering agent 84 is seen . after the microorganisms are attached to the filter pad 60 , the filter pad 60 is then acceptably stored until its usage within the parts washer 10 is desired . in accordance with an embodiment of the present invention , the microorganisms are added directly to the cleaning fluid 72 without being initially attached to the filter pad 60 . thus , the filter pad 60 functions , as both a mechanical filter ( i . e ., straining particulate matter from the fluid 72 ) and as an initial transport medium for the microorganisms , or the filter pad 60 functions solely as a mechanical filter . the cleaning fluid 72 is compatible with ( i . e ., non - toxic to ) the microorganisms such that the microorganisms are capable of living within the cleaning fluid 72 . additionally , the cleaning fluid 72 tends to separate organic waste from parts washed in the basin 14 , as will be discussed in greater detail below . a suitable cleaning fluid 72 , for example , is a mixture of ph neutral emulsifiers and surfactants containing no volatile organic compounds , phosphates , formaldehyde , biocides , or other toxic materials . the emulsifier and surfactants are blended in liquid form to produce a biodegradable , non - toxic , non - caustic , non - flammable oil dispersant cleaner and degreaser . in addition the cleaning fluid 72 preferably contains no known carcinogens , no occupational safety and health act ( osha ) or department of transportation ( dot ) regulated chemicals , no ingredients requiring superfund amendments and reauthorization act title iii reporting ( sara title iii ), no solid waste disposal act as amended by the resources and conservation recovery act of 1976 as amended , 42 usc section 6901 et seq . ( rcra ), and no items on the comprehensive environmental response , compensation and liabilities act ( cercla ) hazardous substance list . in an illustrative embodiment , the exemplary cleaning fluid 72 is a free flowing liquid with a specific gravity of 1 . 083 , a slight pleasant odor , no flash point , a boiling point of 210 degrees fahrenheit , a ph of approximately seven , and is infinitely soluble in water . a suitable cleaning fluid is available from warren chemical corporation of robert , la . as sea wash 7 ( solvent # 5 in table 1 ) or safeworld products sw - 2 . referring further to fig3 in operation , the pump 73 , conduit 74 , and faucet 24 circulate cleaning fluid 72 from the depths of the tank cavity 44 to the basin 18 where parts cleaning takes place . the false bottom member 62 is preferably sufficiently sturdy and well supported such that a variety of parts are capable of being placed thereon for cleaning . in an embodiment , cleaning fluid 72 flows out of the nozzle 26 and the part being washed is oriented within the stream of cleaning fluid 72 exiting the nozzle 26 . the cleaning fluid 72 separates organic waste from the part being washed , and then the cleaning fluid 72 , along with the organic waste and any small particulate washed from the part , flows by gravity through the drain hole 64 and the strainer ( not shown ) associated therewith . the strainer will , of course , keep certain objects from passing through the drain hole 64 . the cleaning fluid 72 , organic waste , and remaining matter then encounter the filter pad 60 . subsequently , the fluid 72 and the organic contaminants pass through the support grid 58 , and drain hole 52 to deposit into the tank cavity 44 . should flow through the filter pad 60 become obstructed , flow will divert through the pair of supplemental drain holes 70 defined through the rear sink wall 48 just above the filter pad 60 . the filter pad 60 functions is to trap the particulate matter and allow the organic contaminants and cleaning fluid 72 to pass therethrough . because the filter pad 60 does not collect the organic contaminants , it is capable of being disposed of as solid waste . if the filter pad 60 is new or relatively new such that all of the microorganisms have not been previously released therefrom , the cleaning fluid 72 releases the dormant microorganisms attached to the filter pad 60 , and the released microorganisms flow with the cleaning fluid 72 and organic contaminants through the drain hole 52 into the tank cavity 44 . within the tank cavity 44 , a large percentage of the microorganisms and organic contaminants will tend to accumulate proximate to the surface of the cleaning fluid 72 such that a large portion of the biodegradation takes place proximate to the surface of the cleaning fluid 72 . this forms a vapor barrier that tends to minimize the evaporation of the cleaning fluid 72 . if living microorganisms are not present in the parts washer 10 , increasing amounts of organic waste will accumulate toward the surface of the cleaning fluid 72 in the tank cavity 44 , and this condition is indicative of the need to replenish the microorganisms . however , if the parts washer 10 is used for normal parts cleaning , it should not be necessary to add new microorganisms to the cleaning fluid 72 of the parts washer 10 . nonetheless , by virtue of the fact that the filter pad 60 is the vehicle for adding microorganisms to the cleaning fluid 72 , as discussed above , microorganisms are added to the cleaning fluid 72 each time a new filter pad 60 is added to the parts washer 10 , as discussed in greater detail below . by virtue of the microorganisms digesting the organic waste within the tank 12 , the cleaning fluid 72 is “ recirculated ” within the parts washer 10 , whereby the cleaning fluid 72 has the potential to last for extended periods of time . it is likely , however , that some cleaning fluid 72 replenishment will be required , however , to make up for evaporative and “ drag - out ” losses incurred as parts are removed from the basin cavity 18 in wet condition . furthermore , by virtue of the cooperative effect of the filter pad 60 ( removing particulate matter ) and the microorganisms ( digesting organic waste ), the tank is , potentially , seldom in need of “ dredging ” to remove waste . referring back to fig1 and 3 , when the off / on switch 32 is in the on position , electricity is supplied to circuitry ( not shown ) which is housed within the control panel 30 by way of a conventional power cord ( not shown ), and the indicator light 34 is illuminated . after the off / on switch 32 is in the “ on ” position , the circuitry , in combination with the thermostat 75 , activates and deactivates the heater 76 . while the thermostat 75 senses that the temperature of the cleaning fluid 72 within the tank cavity 44 is below a desired temperature , the heater 76 is on , and while the thermostat 75 senses that the temperature of the cleaning fluid 72 is at or above the desired temperature , the heater 76 is off . the cleaning fluid 72 is preferably maintained in a temperature range which supports the lives of the particular microorganisms employed within the parts washer 10 . the temperature is preferably maintained in the mesophilic range of approximately 75 ° to 115 ° fahrenheit . the float actuated electric switch 78 also controls the operation of the heater 76 . when the magnet equipped float 80 drops downward due to a low level of the cleaning fluid 72 , the switch 78 is actuated which , in combination with the circuitry , disables the heater 76 and causes the low level warning light 36 to illuminate . operation of the pump 73 is controlled by the timer switch 38 . a user can manually actuate the timer switch 38 which , in combination with the circuitry , causes the pump 73 to operate and automatically cut off after a certain period of time . in accordance with an alternative embodiment of the present invention , an additional switch ( not shown ) is provided that overrides the timer switch 38 such that the pump 73 will remain running as long as the additional switch is “ on ”. referring back to fig2 and 3 , the parts washer 10 is designed to provide easy access to the filter pad 60 . access is obtained by simply lifting the false bottom member 62 out of the basin cavity 18 . there is generally no restrictive engagement between any components that are depicted as exploded away from each other in fig2 whereby the components of the parts washer 10 are readily accessible . while certain of the embodiments of the present invention have been disclosed herein , other embodiments of the apparatus and methods of the present invention will suggest themselves to persons skilled in the art in view of this disclosure and the example below . preliminary screening compared the washing ability of candidate cleaning fluids to mineral spirits . two surfactant based cleaning fluids ( also termed “ fluids ” or “ solvents ” herein ) were preferred as a result . these two ( solvent # 2 and # 5 table 1 , were further tested for their ability to maintain viability of microorganisms suitable for biodegrading organic wastes in objects to be cleaned by the system , method and compositions of the present invention . less preferred solvents were unable to clean substantially as well as mineral spirits . tests were conducted using scrap parts obtained from auto repair shops ( sites g , k , s , w , u in table 1 ). the cleaning ( washing ) effect of solvents alone was tested in 5 sites over several months wherein the solvents were used for washing parts in the routine course of business . each solvent was tested over a period of several weeks to test efficacy of cleaning . solvent # 5 is sea wash 7 . the build up of concentration of oil and grease was noted to rise steadily during the test period to the levels indicated . one liter samples of the fluid were removed at regular intervals and tested at an epa certified testing laboratory to determine parts per million ( ppm ) of organic waste and particulate matter . table la presents summary values ( ppm ) for two candidate solvents used in these tests , and the average ppm over the 5 sites . table 1a presents results of a compilation of data resulting from trials of the two cleaning fluids that gave the best results when tested prior to the introduction of microorganisms . both solvents are water - based , non - toxic , surfactants . based on the tests comparing the solvents to the cleaning ability of mineral spirits and on the results in table 1a , solvent # 5 ( sea wash 7 ) was selected to test with microorganisms . the same procedure used to generate table 1a , was used , that is , solvent # 5 and microorganisms were used to clean parts as a routine part of business at the same 5 sites . approximately 7 × 10 9 colony forming units were affixed to a filter of dimensions of approximately 12 × 21 inches . results in ppm of tests on one liter samples over time , show a dramatic effect of microorganisms on reducing the ppm . upon introducing microorganisms , the oil and grease concentrations dropped dramatically to the levels indicted in table 1b . laboratory tests indicated that it is possible to virtually eliminate oil and grease by continuing to circulate , aerate , and add microorganisms in fluid removed from use in parts washing . this suggested a compartment of the washing system that could be used to treat fluid and recirculate it to the compartment wherein objects are being washed . fig5 shows a bar graph of the average ppm and standard deviation for solvent # 5 alone compared to solvent # 5 with microorganisms . fig6 illustrates the steady state reached in a system of the present invention as determined by ppm of oil and grease detected by epa criteria .