Patent Publication Number: US-11041487-B2

Title: Wastewater sump assembly

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a wastewater sump assembly for receiving and disposing of undesired fluid and, in some cases, solid waste. 
     2. Description of the Related Art 
     Buried sumps are utilized to collect and retain undesired liquid and, in some cases, solid waste. The unwanted material (generally referred to as “wastewater”) is collected in the sump for later pumping to, e.g., an appropriate sewage treatment system such as a city sewer or septic tank. Such devices have particular applicability in instances where sewage cannot flow via gravity to a septic tank or a municipal sewage system. In these cases, the sewage must be pumped to such systems. For example, many residential homes have finished basements including bathrooms which are situated below grade. In such installations, bathroom waste can travel via a gravity flow to a buried sump having a submersible pump useful for periodically removing such waste as the sump reaches a predetermined level of collected wastewater. 
     Typically, the sump will include an inlet formed through a sidewall and receiving the wastewater to be removed. A submersible pump will be housed in the sump and include an actuator such as a float switch which switches on the submersible pump at a defined collection level. A pump outlet is typically positioned through the top of the sump and fluidly connected to the submersible pump such that the submersible pump discharges the sump contents through the outlet. 
     The sump is typically buried below the floor and can be cemented in place in the foundation of, for example, a residence. To provide access to the sump for servicing and/or replacement of the pump and/or pump switch, a lid is selectively securable to the top of the sump. Typical sump assemblies utilize a lid which has a circumferential extent that very closely approximates the circumferential extent of the vertical sump wall. In these installations, the sump wall terminates at the top of the sump and the detachable lid comprises the top surface of the enclosed sump chamber. The pump outlet is piped through the lid and therefore, lid removal necessitates moving the lid relative to the pump outlet which may require attachment and detachment of the pump outlet to the pump and/or resealing of the pump outlet relative to the lid. Further, such arrangements require very lengthy seals between the sump lid and the sump body, as the lid is sized to be generally coextensive with the upright wall defining the sump basin. 
     Alternative sump lids include split lid assemblies in which the typical, generally circular lid is split into two pieces. An example of such a lid can be found in U.S. Pat. No. 4,832,227. In a split lid configuration, sealing must be provided not only around the entire circumference of the two lid halves but also between the split in the two piece lid assembly. Therefore these assemblies require even longer runs of sealing between the sump lid and sump basin. 
     SUMMARY OF THE INVENTION 
     The present disclosure relates to a wastewater sump assembly for receiving and disposing of undesired fluid and, in some cases, solid waste. Exemplary embodiments of the present disclosure include a sump basin having a base, an upstanding wall and a top extending inwardly from the upstanding wall. The base, upstanding wall and top are formed of an integral, monolithic material so that no seams are presented between the base and the upstanding wall and no seams are presented between the upstanding wall and the top. Because the top of the sump basin is defined by a wall that is monolithically and integrally formed with the upstanding wall of the sump basin, a seal surrounding the perimeter of the sump basin is not required. 
     The top of the monolithic basin of the present disclosure includes a pump access aperture sized to allow passage of a submersible pump. A pump access cover is provided to completely cover and seal the pump access aperture. A number of fasteners are utilized to selectively secure the pump access cover to the basin, with the pump access cover hermetically sealed relative to the basin top. With the pump access cover secured in position, it is flush or recessed with the top of the sump defined by the integral, monolithic wall of the sump. 
     A submersible pump positioned within the sump includes a discharge outlet connected to vertical piping which may extend through the top of the sump. In an exemplary embodiment of the present disclosure, the discharge piping may be connected to an outlet pipe stub positioned through the top of the sump and terminating in a recessed area recessed from the uppermost portion of the sump. The recessed area may also include a vent pipe stub positioned through the top of the sump, but completely contained within the recessed area, so that an item positioned flush with the uppermost portion of the sump will not contact either the outlet pipe stub or the vent pipe stub. Providing outlet and vent pipe stubs which are positioned in a recessed area of the top of the sump facilitates easy connection to outlet and vent piping, while also allowing for the easy stacking of a plurality of sump assemblies one atop the other for storage prior to delivery to the job site. 
     A variety of switches can be utilized to actuate the submersible pump housed within the sump of the present disclosure. Embodiments of the present disclosure utilize a switch access cover which can be secured and hermetically sealed relative to the basin top. Like the discharge and vent pipe stubs, the switch access cover can be positioned in a recessed area, so that no part of the switch assembly extends above the uppermost portion of the sump top. Alternative switch assemblies useable with the present disclosure include float assemblies and a diaphragm switch assembly. Switch assemblies of the present disclosure include congruent switch access covers to allow for easy removal and replacement of a switch of a first type with a switch of the second type. 
     In embodiments of the present disclosure, the switch access cover covers and hermetically seals a switch access aperture sized to allow passage of a float switch. In alternative embodiments of the present disclosure, the switch access cover may include a cord access aperture through which at least one electric cord passes. The switch assembly of this form of the present disclosure may further include a cord seal including an electric cord aperture, the cord seal operable to sealingly engage the electric cord and the switch access cover to provide a fluid tight seal therebetween. The switch assembly of this form of the present disclosure may further include a U-shaped handle rotatably connected to the switch access cover. The U-shaped handle having a base and a pair of extensions extending from the base to form the “U-shape”. One of the pair of extensions of the U-shaped handle has a first rotated position in which such extension engages the cord seal to retain the cord seal in sealing engagement with the switch access cover and the electric cord and a second rotated position in which it disengages the cord seal. In alternative forms of the present disclosure an E-shaped handle may be utilized in lieu of a U-shaped handle, with one of the three extensions from the base of the E acting as described above with respect to the U-shaped handle to selectively engage the cord seal to retain the cord seal in sealing engagement with the switch access cover and the electric cord. 
     Alternative embodiments of the present disclosure may utilize a diaphragm switch which is positioned outside of the sump. The diaphragm switch of this form of the present disclosure includes a diaphragm housing with a diaphragm positioned in the diaphragm housing and hermetically sealed relative to the housing so as to divide the housing into a sensing chamber and a switching chamber. The sensing chamber is hermetically sealed by the diaphragm from the switching chamber. The switching chamber is fluidly connected to ambient air, while the sensing chamber is fluidly connected with the interior of the sump basin by a riser. The riser is positioned such that an opening in the distal end of the riser is in fluid communication with a quantity of fluid contained in the sump. As the quantity of fluid in the sump rises, the diaphragm switch is actuated to close a switch and allow operation of the submersible pump to expel the contents of the sump until the pressure against the diaphragm is decreased to a set point, deactuating the diaphragm switch. 
     The disclosure, in one form thereof, provides a wastewater sump including a basin formed from a base, an upstanding wall extending upwardly from the base, and a top extending inwardly from the upstanding wall. In this form of the present disclosure, the base, upstanding wall and top may be formed of an integral, monolithic material, whereby no seams are presented between the base and the upstanding wall and no seams are presented between the upstanding wall and the top. The basin includes an inlet sized to allow ingress of a quantity of sump contents in the form of at least one of a liquid and a liquid/solid mixture and an outlet sized to allow egress of the sump contents. In forms of the present invention, the outlet may be formed through the top of the basin. The basin of the present disclosure is sized to receive a submersible pump useable to expel the contents of the basin. 
     In certain alternative forms of the present disclosure, the basin may have a capacity of at least 30 gallons. In alternative forms of the present disclosure, the upstanding wall of the basin defines an upstanding wall perimeter adjacent to the top, the top occupying at least 50% of an area defined by the upstanding wall perimeter adjacent to the top. In alternative forms of the present disclosure, the top may occupy 50% to 70% of an area defined by the upstanding wall perimeter adjacent to the top. 
     In alternative forms of the present disclosure, the inlet may be positioned through the upstanding wall. Further, the basin may include a vent aperture formed through the top of the basin. 
     In certain forms of the present disclosure, the wastewater sump upstanding wall defines an upstanding wall perimeter adjacent to the top, with the top including a recessed area so that the top extends from the upstanding wall perimeter transverse to the upstanding wall until reaching the recessed area, the top extending a recess distance toward the base at the recessed area and further extending toward the upstanding wall at the recess distance to form a recessed surface extending transverse to the upstanding wall. In this form of the present disclosure, the outlet and vent aperture may be formed in the recessed surface. 
     In alternative forms of the present disclosure, the wastewater sump may include a vent conduit extending through a vent aperture and a discharge conduit extending through a discharge outlet. In certain forms of the present invention, the vent conduit and the discharge conduit may extend externally of the basin from a surface recessed from the top such that the vent conduit and the discharge conduit present external connection piping that is recessed from the top of the basin. 
     In certain forms of the present disclosure, the wastewater sump may include a pump access cover, with the top of the basin having a pump access aperture sized to allow passage of the submersible pump, the pump access cover is sized to completely cover the pump access aperture. A pump access cover seal may be associated with the pump access cover to sealingly engage the pump access cover in the basin when the pump access cover is secured to the basin. A plurality of fasteners may be employed for selectively securing the pump access cover to the basin, the pump access cover defining the largest opening in the top of the basin. In alternative forms of the present disclosure, an outlet and vent aperture may be formed through the basin and will be discrete from the pump access opening. In certain forms of the present disclosure, the pump access aperture may define a circular aperture having a diameter of no more than 12 inches. In alternative forms of the present disclosure, the pump access aperture may have a diameter of about 10-16 inches. 
     In alternative forms of the present disclosure, the top of the basin may include a switch access aperture sized to allow passage of a float switch. In these forms of the present disclosure, a switch access cover sized and configured to selectively completely cover the switch access aperture is provided, with a switch access cover seal associated with the switch access cover to selectively sealingly engage the switch access cover and the basin when the switch access cover is secured to the basin. A plurality of fasteners may be employed to selectively secure the switch access cover to the basin. The switch access aperture may, in certain embodiments, be formed in a recess surface in the top of the basin such that the switch access cover is securable to the recessed surface but does not protrude beyond the top of the basin. 
     Certain embodiments of the switch access covers of the present disclosure may include U or E-shaped handles rotatably connected to the switch to provide a gripping surface for removal of the switch access cover and to selectively secure a cord seal in place relative to the switch access cover. 
     Switches such as float switches and diaphragm switches may be employed to actuate the submersible pump utilized with the present disclosure. In certain embodiments of the present disclosure, a diaphragm switch may include a housing secured to a switch access cover, so that with the switch access cover secured to the basin, the diaphragm housing is positioned external of the basin. In these forms of the present disclosure, a diaphragm is positioned in the diaphragm housing and hermetically sealed relative to the diaphragm housing so as to divide the housing into a sensing chamber and a switching chamber. The sensing chamber is hermetically sealed by the diaphragm from the switching chamber and the switching chamber is fluidly connected to ambient pressure. A switch is housed in the switching chamber and a riser pipe is placed in fluid communication with the sensing chamber and the diaphragm. The riser pump extends into the sump and includes an open distal end spaced from the diaphragm housing. The contents of the sump basin can flow into the riser pipe such that they will cause an increased pressure on the diaphragm to selectively actuate the switch contained in the switching chamber. In alternative forms of the present disclosure, two different switch types are secured to congruent switch access covers and are selectively securable to the sump so that alternative switch subassemblies may be utilized to selectively actuate a submersible pump placed in the sump basin. 
     In alternative forms of the present disclosure, a wastewater sump may include a basin formed from a base, an upstanding wall extending upwardly from the base and a top extending inwardly from the base, the base, the upstanding wall and the top formed of an integral, monolithic material, so that no seams are presented between the base and the upstanding wall and no seams are presented between the upstanding wall and the top. The basin may include an inlet sized to allow ingress of a quantity of sump contents in the form of at least one of a liquid and a liquid/solid mixture and an outlet to allow egress of the sump contents, with the basin sized to receive a submersible pump to effect removal of the sump contents. The top of the basin of this form of the present disclosure includes a pump access aperture sized to allow passage of the submersible pump and a pump access cover sized to completely cover the pump access aperture. The pump access cover seal may be associated with the pump access cover to sealingly engage the pump access cover and the basin when the pump access cover is secured to the basin. A plurality of fasteners may be utilized to selectively secure the pump access cover to the basin. The pump access cover of this form of the present disclosure defines the largest opening in the top of the basin. The top of the basin defines a sump perimeter adjacent to a transition from the upstanding wall to the top. The pump access cover defines a pump access cover perimeter such that the pump access cover perimeter has a length of no more than about 60% of the length of the sump perimeter. A number of fasteners may be positioned adjacent to the pump access cover perimeter to hermetically seal the pump access cover to the basin. 
     The present disclosure describes and illustrates a number of different features associated with a sump basin. Features described and illustrated with reference to any single embodiment of the present disclosure may be incorporated into all other embodiments of the present disclosure. Stated another way, any of the various features described in this document may be interchangeably used with any combination of the remaining features. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective, partial sectional view of a sump assembly in accordance with the present disclosure; 
         FIG. 2  is an exploded view illustrating a sump assembly in accordance with the present disclosure; 
         FIG. 3  is a plan view of a sump assembly of the present disclosure showing the pump access cover and the switch access cover engaged with the top of the sump and further illustrating an alarm positioned atop the sump access cover for packaging; 
         FIG. 4  is a plan view illustrating the sump basin of the present disclosure with the pump access cover and switch access cover removed; 
         FIG. 5  is a perspective view of a float assembly in accordance with the present disclosure; 
         FIG. 6  is a partial perspective view of the float assembly of  FIG. 7 , illustrating the E-shaped handle articulated to a position allowing for removal of the cord seal; 
         FIG. 7  is an exploded elevation view illustrating the cord seal of  FIG. 6  positioned about an electric cord prior to engagement with the switch access cover illustrated in  FIG. 6 ; 
         FIG. 8  is a plan view of the cord seal illustrated in  FIG. 7 ; 
         FIG. 9  is an elevation, partial sectional view illustrating the electric cord seal engaged with the switch plate to seal an electric cord relative to the switch plate; 
         FIG. 10  is a partial plan view of the assembly illustrated in  FIG. 9 ; and 
         FIG. 11  is a sectional view of a diaphragm switch in accordance with the present disclosure. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed. 
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION 
     Referring to  FIG. 1 , sump assembly  20  includes basin  22  formed from base  24 , upstanding wall  26  and top  28 . As illustrated, upstanding wall  26  extends axially upwardly from base  24  and top  28  extends radially inwardly from upstanding wall  26 . Basin  22  is a rotational molded (sometimes referred to as “roto molded”) polyethylene basin, with an integral, monolithic material forming base  24 , upstanding wall  26  and top  28 . Basin  22  may have a capacity of about 30, 40, 50 or 60 gallons. In an alternative embodiment, basin  22  may have a capacity anywhere in the range of about 30-60 gallons. With base  24 , upstanding wall  26  and top  28  roto molded to be formed from an integral, monolithic material, no seams are presented between base  24  and upstanding wall  26 . Similarly, no seams are presented between upstanding wall  26  and top  28 . Because top  28  of basin  22  is defined by a wall that is monolithically and integrally formed with upstanding wall  26  of basin  22 , a seal surrounding the perimeter of basin  22  is not required to fluidly isolate the interior cavity of sump assembly from the ambient environment, as further described below. 
     Upstanding wall  26  of basin  22  includes four inlet pads  66  evenly circumferentially spaced about the outer surface of wall  26 , as illustrated in  FIGS. 1 and 2 . A first inlet pad  66  includes inlet  68  comprising an open ended channel formed therethrough. Inlet  68  may be integrally roto molded with the remainder of basin  22 . The remaining three inlet pads  66  can be drilled to provide additional inlets should basin  22  be connected to multiple sources of wastewater. 
     Referring to  FIGS. 2 and 4 , basin  22  includes pump access aperture  30  formed through top  28 . Pump access aperture  30  is sized to allow passage of submersible pump  32  ( FIG. 1 ). Submersible pump  32  may be a Franklin Electric model 9SN-CIM submersible pump, available from Franklin Electric, Co. of Fort Wayne, Ind. Referring to  FIG. 4 , exemplary basin  22  includes an outermost extent defining diameter d S  of about 24 inches. Upstanding wall  26  generally diverges (e.g., in a frusto-conical fashion) from base  24  to top  28  such that the radial outermost extent of basin  22  is defined adjacent to top  28 . In an embodiment in which d S  is about 24 inches, the diameter of pump access aperture  30 , d P  is about 12 inches. 
     Pump access aperture  30  defines the largest opening in the top of basin  22 . Because diameter d P  defines a perimeter that is substantially less than the perimeter defined by diameter d S , significantly less lineal sealing distance is required to seal the top of basin  22  relative to prior art embodiments in which the sump top was formed as a discrete separate part which was sealed relative to the upstanding wall of the predicate sump basins. As depicted in the attached drawings, pump access aperture  30  defines a circular aperture through top  28  of basin  22 . In alternative embodiments, pump access aperture  30  may be generally (that is, approximately) circular, e.g., it may be defined by a polygon of at least 5 sides. In the event that pump access aperture  30  is polygonal in form, its size would be defined by the radius or diameter of the largest circle circumscribed by such polygon. 
     Submersible pump  32  ( FIG. 1 ) is an impeller pump having an inlet through which submersible pump  32  draws fluid and solids contained in basin  22  to be expelled by the impeller through pump outlet  34 . After submersible pump  32  is received into basin  22  through pump access aperture  30 , outlet pipe  36  is secured to pump outlet  34 , e.g., by threading. Outlet pipe  36  terminates short of the underside of top  28  of basin  22 . Elastomeric pipe sleeve  38  is positioned about outlet pipe  36  and outlet pipe stub  40  ( FIG. 2 ), which will be described in more detail below. Hose clamps may be utilized to secure elastomeric pipe sleeve  38  to outlet pipe  36  and outlet pipe stub  40 . Outlet pipe stub  40  can then be connected to further outlet piping connected to, e.g., a city sewer or septic tank. 
       FIGS. 2 and 4  illustrate pump access cover  42  removed from basin  22  to allow insertion or removal of submersible pump  32 . Basin  22  includes flange  44  defined around pump access aperture  30 . A plurality of fastener receptacles  46  are positioned about flange  44 . Fastener receptacles  46  may take the form of, e.g., aluminum inserts positioned through flange  44  and adapted to receive a plurality of fasteners  48 . Fasteners  48  may be externally threaded bolts sized to cooperate with internal threaded apertures formed in fastener receptacles  46 . In use, fasteners  48  are positioned through fastener apertures  50  in pump access cover  42  to hermetically seal pump access cover  42  to top  28  of basin  22 . Prior to securement of fasteners  48 , a seal is interposed between pump access cover  42  and flange  44 . Such a seal may be an annular, elastically deformable gasket incorporated into the under surface of pump access cover  42 , or positioned atop flange  44 . With pump access cover  42  secured in position, as illustrated in  FIG. 1 , it is flush with top  28  of basin  22 , owing to the fact that flange  44  is recessed from the uppermost surface of top  28 . 
     Referring to  FIG. 4 , top  28  includes discharge aperture  52  and vent aperture  54  formed therethrough. Referring to  FIG. 2 , outlet pipe stub  40  and vent pipe stub  56  are sized to be positioned through discharge aperture  52  and vent aperture  54  ( FIG. 4 ), respectively. Seal  58  is interposed between outlet pipe stub  40  and discharge aperture  52  to effect sealing therebetween. Similarly, seal  60  is interposed between vent pipe stub  56  and vent aperture  54  to effect sealing therebetween. Referring to  FIGS. 1-4 , outlet pipe stub  40  and vent pipe stub  56  both extend through top  28  and into recessed area  62  formed in top  28 . Recessed area  62  is formed by top  28  having an extension extending axially downwardly a recess distance toward base  24  and thereafter extending in a transverse direction (e.g., radially outwardly and/or inwardly) toward upstanding wall  26  to form recess surface  64  ( FIG. 3 ). With outlet pipe stub  40  and vent pipe stub  56  positioned in recessed area  62 , outlet pipe stub  40  and vent pipe stub  56  are both positioned external to basin  22  and available for securement to further piping to define the outlet and vent extending from basin  22 , without extending past the uppermost extent (i.e., the axial terminal end) of basin  22 . As described above, the outlet may be fluidly connected with a city sewer or septic tank. The vent may be fluidly connected to a pipe extending through the roof of the residence in which basin  22  is installed to allow for venting of the interior of basin  22  to ensure that a pressure buildup therein does not occur. 
     A variety of switches can be utilized to actuate submersible pump  32  to remove wastewater previously received through inlet  68  into basin  22 . Any of the many, well known float switches may be utilized in accordance with the present invention. In the embodiment illustrated in  FIG. 1 , float switch  74  is operable to actuate submersible pump  32 . Float switch  74  includes electric cord  80  extending therefrom. Electric cord  80  is tethered to riser  72  such that the buoyancy of float  78  on fluid in basin  22  will cause a change in the attitude of float  78  to open or close the electric circuit depending on whether the fluid in basin  22  is rising or lowering. 
     Float switches  74 ,  76  may be Franklin Electric Model RFSN series float switches available from Franklin Electric Co., Inc of Fort Wayne, Ind. Each of float switches  74 ,  76  includes a float  78  including a sphere positioned within a raceway and operable to open and close an electrical circuit in response to a change in attitude of the float, which causes a repositioning of the sphere. Electric cords  80  extending from and electrically connected to floats  78  may terminate in a piggyback plug having a male electrical connector for connection to a standard wall outlet and a female electrical connector for further connection to a subsequent male connector. With the piggyback plug connected to a wall outlet, floats  78  are operable to selectively close an electric circuit through the piggyback plug to allow the passage of current therethrough. 
     Specifically, electric cord  80  is connected at its distal end (not shown) to a piggyback connector configured to be engaged with a standard wall socket. Similarly, an electric cord is connected to submersible pump  32  and is operable to provide power to submersible pump  32  to actuate submersible pump  32 . Submersible pump  32  does not include an integral switch and therefore operates when it receives electrical current. Because it is connected to a wall outlet through the piggyback switch of float switch  74 , closing of the circuit caused by raising the float  78  associated with float switch  74  completes the circuit from the electrical cord associated with submersible pump  32  to the wall outlet to actuate submersible pump  32 . Float switch  76  operates in a similar fashion and may be connected to an alarm which indicates that submersible pump  32  is not functioning properly and therefore the liquid level in basin  22  is rising higher than that which would be allowed by float switch  74 . Such an alarm is schematically illustrated as alarm  81  in  FIGS. 1-3  of the present application. In the event that float switches  74  and  76  are both utilized with a submersible pump  32 , three electric cords will extend from the interior of basin  22  to an exterior thereof. 
     Floats  78  may be made in accordance with the disclosure of U.S. Pat. Nos. 5,087,801 and 5,142,108, the entire disclosures of which are both explicitly incorporated by reference herein. For example, each float  78  of float switches  74 ,  76  may include an internal ball which, with floats  78  positioned as illustrated in  FIG. 1 , with a distal end thereof pointed downwardly toward base  24  of basin  22 , is incapable of closing the electric circuit to allow current to flow from the wall socket through a piggyback plug connected to the float switch and thereafter to the power cord of submersible pump  32 . If the attitude of a respective float switch  74  or  76  is changed such that the distal end thereof points upwardly toward top  28  of basin  22 , then the internal ball will actuate a contact to electrically close the electrical circuit and allow current from the wall outlet to pass through the piggyback switch into the plug of the power cord of submersible pump  32  to energize submersible pump  32 . 
     Referring still to  FIGS. 1, 2 and 5 , riser  72  of float switch subassembly  70  is secured to switch access cover  82 . Specifically, clevis pin  84  ( FIG. 5 ) is positioned through a transverse aperture in both riser  72  and boss  85 , which extends downwardly from switch access cover  82  and into which riser  72  is positioned. Referring to  FIG. 4 , switch access aperture  86  is sized to allow passage of float switches  74 ,  76  so that, with float switches  74 ,  76  secured to riser  72 , riser  72  and switches  74 ,  76  may all be inserted from an exterior of basin  22  through switch access aperture  86  to position float switches  74 ,  76  within basin  22 . Switch access cover  82  is sized to completely cover switch access aperture  86  and be positioned within recessed area  88  as illustrated, e.g., in  FIG. 1 . Recessed area  88  is formed by top  28  having an extension extending axially downwardly by a recess distance toward base  24  and thereafter extending in a transverse direction (e.g., radially outwardly and/or inwardly) toward upstanding wall  26  to form recessed surface  90  ( FIG. 4 ). A plurality of fastener receptacles  112  ( FIG. 4 ) are positioned about recessed surface  90 . Fastener receptacles  112  may take the form of, e.g., aluminum inserts positioned through recessed surface  90  and adapted to receive a plurality of fasteners  114  ( FIG. 2 ). Prior to securement of fasteners  114 , a seal is interposed between switch access cover  82  and recessed surface  90 . Such a seal may be an annular, elastically deformable gasket incorporated into the undersurface of switch access cover  82 , or positioned atop recessed surface  90 . With switch access cover  82  secured in position, as illustrated in  FIG. 1 , the entire float switch subassembly  70  is recessed from the upper most surface of top  28 . 
     Referring to  FIG. 6 , switch access cover  82  includes cord access aperture  102  through which electric cords  80  of float switches  74 ,  76  and the power cord to submersible pump  32  can be positioned. Referring to  FIGS. 6-10 , cord seal  100  comprises a grommet having a compressible, tapered wall  104 , cord apertures  106  and radial slits  108 . In one exemplary embodiment, cord seal  100  is made in accordance with U.S. Pat. No. 6,348,657, the entire disclosure of which is hereby explicitly incorporated by reference herein. In the embodiment illustrated, cord seal  100  includes two cord apertures  106 . In this embodiment, the electrical cord from submersible pump  32  and an electrical cord from one float switch  74  may pass through cord seal  100 . In alternative embodiments, utilizing alarm float switch  76 , cord seal  100  will include three cord apertures  106  and associated radial slits  108 . Each cord aperture  106  includes a radial slit  108  extending radially outwardly therefrom and intersecting tapered wall  104 . Radial slits  108  may be utilized to allow electric cord  80  to pass from tapered wall  104  to cord apertures  106 . With one or more electric cords  80  traversing cord apertures  106 , cord seal  100  can be positioned within cord access aperture  102 . 
     In one exemplary embodiment, cord access aperture  102  is formed from tapered wall  110 . Tapered wall  110  includes a taper angle similar to tapered wall  104  of cord seal  100 . With electric cord(s) positioned through cord apertures  106 , cord seal  100  may be pressed into cord access aperture  102  such that tapered wall  110  cooperates with tapered wall  104  of cord seal  100  to compress cord seal  100  and sealingly engage the opposing walls forming radial slits  108 , as illustrated in  FIG. 10 . In the configuration illustrated in  FIG. 10  (and with electric cords  80  occupying cord apertures  106 ), cord seal  100  cooperates with switch access cover  82  to seal electrical cords  80  passing through cord access aperture  102  relative to switch access cover  82 . 
     Referring to  FIGS. 5-10 , float switch subassembly  70  includes E-shaped handle  92  selectively pivotally secured to switch access cover  82 . E-shaped handle  92  includes base  94  with extensions  96  extending therefrom to create an “E” shape. Intermediate extension  96  is cannulated such that pivot bolt  98  extends therethrough. Pivot bolt  98  may be secured to switch access cover  82  by threaded engagement into a blind bore formed in switch access cover  82 . Pivot bolt  98  may be loosened such that E-shaped handle  92  is pivotable about pivot bolt  98  such that E-shaped handle  92  may be rotated to the position illustrated in  FIG. 6  in which no extensions  96  of E-shaped handle  92  engage cord seal  100 . E-shaped handle  92  may also be rotated from the position illustrated in  FIG. 6  to the position illustrated in  FIG. 5  in which one of extensions  96  engages cord seal  100  to hold cord seal  100  firmly in place relative to switch access cover  82 . In this position, pivot bolt  98  can be tightened such that E-shaped handle  92  is no longer pivotable relative to switch access cover  82  and the extension  96  firmly abuts cord seal  100 . With extension  96  engaging cord seal  100 , cord seal  100  cannot be disengaged from the frictionally engaged position illustrated in  FIG. 9 . 
     While handle  92  is described as having an “E” shape, taking ½ of base  94  and two adjacent extensions  96 , it can also be said that handle  92  is “U” shaped. In this regard, it is noted that only two extensions  96  are necessary to achieve the functionality described above. Therefore, a U-shaped handle  92  defined by two neighboring extensions  96  is also contemplated within the present disclosure. 
     Switch access cover  82  has a generally symmetrical outer perimeter; however, fastener apertures  116  through which fasteners  114  are positioned ( FIG. 2 ) to secure switch access cover  82  to basin  22  are asymmetrically arranged as illustrated, e.g., in  FIG. 3 . Asymmetric arrangement of fastener apertures  116  ensures that switch access cover  82  is repeatably securable in one orientation only relative to basin  22 . Similarly, riser  72  may be keyed to boss  85  such that riser  72  is insertable in boss  85  only in a single predetermined orientation. Referring to  FIG. 5 , thumbscrews  118  and clamps  120  may be utilized to secure electric cords  80  to riser  72 . Specifically, a lag bolt may be positioned through each clamp  120  and threadably engaged by thumbscrew  118 , which takes the form of a threaded fastener such as a wingnut. Similarly, clamps  120  may be over molded about the head of a lag bolt, with the threaded end of the lag bolt extending therefrom. Riser  72  includes transverse apertures through which the bolts extending from clamps  120  can extend. As illustrated in  FIG. 5 , these transverse apertures are not aligned (i.e., the longitudinal axes of the apertures are not parallel), so that floats  78  will extend at different rotated positions with respect to riser  72 . Keying of switch access cover  82  to sump basin  22 , riser  72  to switch access cover  82  (via boss  85 ), and floats  78  relative to riser  72  ensures that floats  78  will be installed at a position of maximum open area in the interior of basin  22  and be free from obstruction from any adjacent structures. The thumbscrew/clamp combinations for tethering float switches  74 ,  76  to riser  72  further allow for quick and easy removal and replacement of the respective float switches. 
       FIG. 11  illustrates diaphragm switch subassembly  122 . Diaphragm switch subassembly  122  may be utilized in place of float switch subassembly  70 . Diaphragm switch subassembly  122  includes diaphragm housing  124  formed of upper diaphragm housing  126  secured to a lower diaphragm housing in the form of switch access cover  128 . As illustrated in  FIG. 11 , lag bolts may be utilized to secure upper diaphragm housing  126  to switch access cover  128 . Diaphragm  130  is positioned in diaphragm housing  124  and is hermetically sealed thereto. For example, diaphragm  130  may be trapped between upper diaphragm housing  126  and switch access cover  128 . Diaphragm  130  is formed of an elastomeric material and separates diaphragm housing  124  into sensing chamber  132  and switching chamber  134 . Sensing chamber  132  is fluidly connected with riser pipe  136  and end bell  138 . In the sectional view illustrated, end bell  138  is shown positioned proximate to but spaced from base  24  of basin  22 . 
     Screen  140  is positioned within an open end of end bell  138 . With riser pipe  136  and end bell  138  positioned relative to base  24  of basin  22  as illustrated in  FIG. 11 , the contents of basin  22  in the form of liquid and/or liquid and solid waste can flow into riser pipe  136 . Screen  140  has a pore size sufficient to filter large solids from entering end bell  138 . With end bell  138  extending into the contents of basin  22  such that fluid in basin  22  covers the opening(s) in end bell  138 , the fluid in basin  22  will cooperate with diaphragm  130  to hermetically seal the interior of end bell  138 , riser pipe  136  and sensing chamber  132 . As the fluid level in basin  22  rises, the air contained in end bell  138 , riser pipe  136  and sensing chamber  132  will be forced upward against diaphragm  130 . Switching chamber  134  is fluidly connected to ambient pressure by aperture  150 . Therefore, as the level of fluid in basin  22  rises and the pressure in end bell  138 , riser pipe  136  and sensing chamber  132  increases, a pressure differential forms that urges diaphragm  130  to expand and move upwardly. Owing to the elastomeric nature of diaphragm  130 , it will, under the influence of such increased pressure, move upwardly into switching chamber  134 . As illustrated in  FIG. 11 , diaphragm  130  includes metal plate  142  secured thereto. As the level of the contents in basin  22  rises and diaphragm  130  moves upwardly, metal plate  142  engages hinged arm  144  and presses hinged arm  144  toward the top of diaphragm housing  122  to actuate switch  146 . Switch  146  is configured to close an electrical circuit between contacts  148  upon actuation of switch  146  by diaphragm  130 , metal plate  142  and hinged arm  144 . Contacts  148  may be electrically connected to a piggyback plug as described above with respect to float switch assembly  70 . 
     In alternative forms of diaphragm switch subassembly  122 , the distal end of riser pipe  136 , i.e., end bell  138 , may be in fluid communication with the contents of basin  22  not only through an open distal end of end bell  138 , but also through transverse apertures in the wall defining end bell  138 . Further, transverse apertures through the wall defining end bell  138  may be utilized in lieu of an open distal end of end bell  138 . In such configurations, the distal end of end bell  138  may be positioned directly atop base  24  of basin  22 , with the transverse apertures defining the “open distal end”. If apertures through the wall defining end bell  138  are utilized to provide fluid communication between riser pipe  136  and the interior of basin  22 , such apertures may be overlaid with a screen in similar fashion to the open distal end of end bell  138  illustrated in  FIG. 11  to thereby prevent large particles from entering end bell  138 . Further, the spacing of the distal end of end bell  138  relative to base  24  may be such as to preclude entry of large particles into end bell  138 . 
     Switch access cover  128  includes a periphery identical to the periphery of switch access cover  82  of float switch subassembly  70 , including an identical pattern of fastener apertures  116 . Further, switch access cover  128  can be sealingly engaged with top  28  of basin  22  in the same manner described above with respect to switch access cover  82 . Switch access cover  82  and switch access cover  128  are interchangeably securable to top  28  of basin  22 . While not illustrated in  FIG. 11 , switch access cover  128  will include a cord access aperture similar to cord access aperture  102  ( FIG. 6 ) of float switch subassembly  70 . Because diaphragm housing  124  is positioned atop switch access cover  128  such that, with switch access cover  128  secured in position relative to basin  22 , diaphragm housing  124  is positioned exterior of basin  22 , an electrical cord connected to contacts  148  does not have to pass through top  28  of basin  22 . Therefore, a cord seal associated with the cord access aperture through switch access cover  128  will not need to accommodate the electric cord from the switch assembly. Therefore, a cord seal having a single cord aperture and associated radial slit may be utilized to allow passage of the electrical cord from submersible pump  32 . In the event that a secondary alarm float is tethered to riser pipe  136 , the electrical cord associated therewith will pass through the cord access aperture and cord seal utilized with diaphragm switch subassembly  122 . In such an embodiment, the cord seal will include two cord apertures and associated radial slits to allow passage of both the electrical cord associated with submersible pump  32  and the electrical cord associated with the alarm float switch. 
     As described above, top  28  is part of an integral, monolithic wall forming basin  22 . In the exemplary embodiment illustrated, top  28  includes only four openings therethrough. Referring to  FIG. 4 , these four openings are: pump access aperture  30 , switch access aperture  86 , discharge aperture  52  and vent aperture  54 . As described above, pump access aperture  30  is the largest aperture formed through top  28 . In an exemplary embodiment, pump access aperture  30  accounts for removal of approximately 25% of the top area defined by the perimeter of upstanding wall  26  adjacent to top  28 . Switch access aperture  86  together with discharge aperture  52  and vent aperture  54  may account for the loss of another 5% of such area such that top  28  presents a barrier to entry and exit through the perimeter of upstanding wall  26  adjacent to top  28  of at least 70% of such area. In alternative embodiments, top  28  presents a barrier to entry and exit through the perimeter of upstanding wall  26  adjacent to top  28  of at least anywhere in the range of 50-70% of such area. In embodiments, top  28  occupies 50% of the top area defined by the perimeter of upstanding wall  26  adjacent to top  28 . 
     Referring to  FIG. 1 , shipping cover  152  may be secured to top  28  of basin  22 , with alarm  81  positioned therebeneath for shipping. In use, Alarm  81  will be, e.g., wall mounted. Alarm  81  may include an audible and/or visible alarm signal which is triggered by actuation of an alarm switch such as float switch  76  described above. 
     As illustrated in  FIG. 1 , shipping cover  152  includes cutout  154  sized to accommodate passage of vent and discharge piping connected to vent pipe stub  56  and outlet pipe stub  40 , respectively. Therefore, after installation of basin  22 , shipping cover  152  may be re-secured to top  28  of basin  22  to provide for an aesthetically pleasing appearance while preventing debris from contacting the majority of top  28  of basin  22 . Prior to shipping, shipping cover  152  may be affixed to top  28  of basin  22  such that cutout  154  is not aligned with discharge pipe stub  40  and vent pipe stub  56 , so that shipping cover  152  prevents liquid from thereby entering basin  22 . This can be particularly useful if basin  22  is stored outside prior to delivery to a customer. 
     While this invention has been described as having an exemplary design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.