Abstract:
A method of and an apparatus for rejuvenating a wastewater treatment system of the type including a septic tank, an aerobic treatment unit or the like connected by a pipe to a plugged downstream soil absorption system includes a wastewater treatment unit which is interposed between the septic unit/aerobic treatment unit and the downstream soil absorption system. The wastewater treatment unit includes a single piece or a multiple piece solids settling and retention basin within which is suspendingly supported a wastewater treatment mechanism essentially of the type disclosed in U.S. Pat. No. 5,264,120. The wastewater treatment mechanism includes filters for filtering and settling solids from wastewater and flow equalization ports for effecting flow equalization thereby eliminating flow surges to the downstream plugged soil absorption system. By utilizing an extremely compact solids settling and retention basin and its attendant operative components, solids are prevented from passing beyond the wastewater treatment unit to the failed soil absorption system. In this fashion the wastewater treatment unit of the present invention can rejuvenate wastewater treatment systems which have failed, and if installed prior to such failure, can extend the life thereof substantially indefinitely. The latter and other advantages are achieved at relatively low cost, absent destruction of existing sod or lawn, moving fencing, trees, etc., and absent creating a hazard for individuals, particularly small children.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The most widely used on-site wastewater treatment systems for individual households have traditionally been either septic systems or aerobic treatment units. Septic systems generally include a septic tank followed by a leaching tile field or a similar absorption device located downstream, but physically on-site of the individual residence. The septic tank allows for larger/heavier solids in the sewage to settle out within the tank, while anaerobic bacteria partially degrade the organic material in the waste. The discharge from the septic tank is further treated by dispersion into the soil through any number of soil absorption devices, such as a leaching tile field, whereby bacteria in the soil continue the biodegradation process.  
           [0002]    The conventional septic system is typically a flow-through system. The septic tank and the tile field are positioned so that sewage is carried out of the residence and through the treatment system by gravity and hydraulic displacement. As a flow-through system, the tank relies on sufficient hydraulic capacity to slow the velocity of the flow and allows settling of the solids to take place. Unfortunately, as the settable solids accumulate in the bottom of the tank, they displace the beneficial tank volume, effectively increasing the velocity of flow through the tank and decreasing the efficiency of solids removal. Also, as a flow-through system, the velocity of the flow through the tank and the related efficiency of solids removal by gravity are dependent upon the volume and frequency of the incoming sewage. A lower volume and rate of incoming sewage flow allows for greater gravity separation and removal efficiency. Higher volumes and rates of flow therefore decrease gravity settling and solids removal efficiency. Over the course of time, an increasing in volume of organic material is discharged from the tank (due to decreasing removal efficiency) until the total volume of solids discharged over the life of the system exceeds the capacity of the downstream soil absorption system (leaching tile field) to accomplish further treatment. The soil absorption system will then retain solids and become plugged, thereby causing a back-up of sewage into the home. In this situation, the downstream soil absorption system is considered failed. Rejuvenation of a failed soil absorption system is not technologically feasible. Therefore, the downstream soil absorption system or other downstream device must be replaced or a new downstream device installed. However, even if sufficient land area is available toward the installation of a new downstream device, such can be accomplished only at considerable cost and inconvenience. Typically, heavy construction equipment is required to excavate and install any new replacement leaching tile field (a commonly used soil absorption system), or a similar device. This is much more inconvenient and costly then at the time of installation of the original treatment system. Construction equipment operating around an occupied residence frequently requires considerable destruction of hundreds of square feet of existing sod or lawn, moving fences, trees or recreational equipment, and creating a hazard for individuals, particularly smaller children.  
           [0003]    Most aerobic treatment units are also flow through systems. Unlike septic tanks, aerobic treatment units perform primary (anaerobic) treatment and secondary (aerobic) treatment within the confines of the system. This arrangement provides a much higher degree of treatment within a relatively small area. As traditional aerobic treatment units are designed for a much higher removal of solids and organic compounds than anaerobic treatment units, a downstream device is frequently not required or is severely diminished in size compared to one which would be required downstream of a septic tank. In a traditional aerobic treatment unit, the first stage of the process is called pretreatment and provides for anaerobic treatment very much like that provided by a septic tank. A separate, isolated pretreatment chamber contains sufficient hydraulic capacity to slow the velocity of the flow somewhat and allows the settling of some of the solids to take place. Anaerobic bacteria partially degrade the organic material in the waste. As a flow through system, the contents of the pretreatment chamber (partially treated waste) are displaced by incoming sewage, and are transferred to the aeration chamber or biological reactor.  
           [0004]    Within the aeration chamber, air is introduced in controlled amounts creating a proper environment for the development of a number of types of aerobic bacteria. The aerobic bacteria maintain a higher metabolic rate than anaerobic bacteria, which causes them to readily consume the organic material contained in the pretreated sewage. Prior to discharge of this flow through system, the aerobic bacteria (commonly called activated sludge) must be separated from the treated liquid. If the activated sludge particles are allowed to exit the system, two problems occur. First, the activated sludge would not be available to treat additional incoming sewage. As the system is operated on a continuing basis, the cultured bacteria need to be retained for future use. Secondly, if the activated sludge is allowed to be discharged from the system, the organic nature of the sludge would be considered a pollutant if returned directly to the environment.  
           [0005]    Commonly, the activated sludge is separated from the treated liquid by allowing the solids to settle out in a gravity clarifier. In a flow through system, the contents of the aeration chamber containing the activated sludge are hydraulically displaced to the clarifier by partially treated liquid entering from the pretreatment chamber. Once in the gravity clarifier, quiescent conditions allow the activated sludge to slowly settle to the bottom of the chamber while the treated liquid is discharged from the system near the top of the chamber. The clarifier relies on having sufficient hydraulic capacity to slow the velocity of the flow through the chamber and thereby allows the activated sludge solids to settle to the bottom. The settled sludge at the bottom of the clarifier is returned, by various means, to the aeration chamber. This return prohibits the clarifier from accumulating a large volume of solids and thereby reducing the efficiency of solids separation. However, as a flow through system, the settling efficiency of the clarifier is dependent also on the volume and frequency of the incoming sewage flow.  
           [0006]    From the foregoing, it is clearly seen that the efficient and long-term operation of a flow through septic system or a flow through aerobic treatment unit is dependent on eliminating surges and maintaining a uniform, consistent rate of flow through the system. Unfortunately, a uniform, consistent rate of flow through a residential wastewater system is not commonly achieved. Modern homes are furnished with many water using appliances that generate large volumes of sewage flow in compressed periods of time. Wastewater from washing machines, dishwashers, hot tubs, spas, and similar appliances tend to be high in volume and discharge within a short period of time. These concentrated hydraulic surges disrupt the quiescent environment of septic tanks or aerobic treatment units, reducing efficiency of the gravity settling process. This effect causes partially treated waste or biological solids to be discharged to a downstream soil absorption system or other downstream treatment device resulting in premature failure, or causes biological solids to be returned to the environment as a pollutant.  
         SUMMARY OF THE INVENTION  
         [0007]    An object of the present invention is to enhance the operation of new or existing septic tanks or aerobic treatment units to prohibit the discharge of partially treated waste or other organic solids. By installing a novel wastewater treatment unit of the present invention downstream of a new or existing septic tank or an aerobic treatment unit, but upstream of a soil absorption system, device or a discharge point, the discharge of partially treated waste or other organic solids is substantially totally precluded. In particular, the wastewater treatment unit of the present invention is of a relatively compact size and its installation as aforesaid can be accomplished with minimum disturbance to existing yards, landscaping or home sites whose downstream soil absorption system is being newly installed or has been installed for a time and is failing. Even if the downstream treatment system has not failed, the installation of the wastewater treatment unit of the present invention provides enhanced performance benefits to new or previously installed residential wastewater treatment systems at a minimum of cost, effort and installation time. By thus installing the wastewater treatment unit of the present invention into or as part of a residential wastewater treatment system, an increase in the serviceability of the latter is automatically achieved. As the total volume of solids discharged by a secondary treatment system typically accumulate in the downstream soil absorption system or device, premature failure is common. Removal of accumulated solids from a failed or plugged soil absorption device is not technological feasible, but rejuvenation thereof can be achieved by the present invention in the sense that the wastewater treatment unit of the present invention can be installed upstream from the failed soil absorption system and will accumulate solids which can in turn be removed readily from grade thereby preventing solids from passing beyond the wastewater treatment unit to the failed soil absorption system. In this fashion the wastewater treatment unit of the present invention can rejuvenate wastewater treatment systems which have failed and, if installed prior to such failure, can extend the life thereof.  
           [0008]    The latter objects are achieved by a novel wastewater treatment unit utilizing substantially the wastewater treatment mechanism disclosed in U.S. Pat. No. 5,264,120 granted on Nov. 23, 1993 which is housed in a settling and retention basin which collects solids from domestic wastewater discharge. The settling and retention basin includes an inlet and an outlet pipe or invert which are respectively connected to the discharge of a flow-through septic system or a flow-through aerobic treatment unit and a soil absorption system (leaching tile field) or any such other downstream treatment device. Wastewater enters the settling and retention basin and before being discharged therefrom passes through and is treated by a wastewater treatment mechanism (similar to that of U.S. Pat. No. 5,264,120 which is known in the trade as assignee&#39;s Bio-Kinetic® device) which contains three filtration zones, eight settling zones, 37 baffled chamber plates and 280 lineal feet of kinetic filtration, all of which dramatically reduce loading on downstream soil absorption systems. Moreover, within the Bio-Kinetic® device are settling zones which operate in conjunction with filtration and flow equalization to effectively retain BOD and solids which are removed from the flow stream. The Bio-Kinetic® device includes flow equalization ports arranged to manage daily flow variations and control flow through all upstream and downstream treatment processes, higher sustained flow ports which become operative under longer hydraulic surges and, finally, peak flow ports which operate under high, prolonged flow surges. Thus, under all three potential flow patterns, the solids can be settled by the Bio-Kinetic® device and retained in the settling and retention basin for subsequent removal from grade. Since the settling and retention basin has a normal capacity of 52 gallons below an outlet invert, normal liquid and solids retention capacity is quite high, but for special applications additional ring sections and riser sections can be added to dramatically increase the volume of the retention basin and allow water-tight installation at burial depths of up to 12 feet. However, an upper end of the settling and retention basin is at all times exposed above grade and is closed by a heavy duty access cover which permits the removal and cleaning of the Bio-Kinetic® device, the removal of solids from the settling and retention basin, and the re-installation of the Bio-Kinetic® device into the settling and retention basin for continued use. Thus, by installing the wastewater treatment unit of the present invention upstream of new or existing tile fields, sand filters, leaching fields, mounds, irrigation systems, constructed wet lands or any process that is biologically sensitive, hydraulically sensitive or difficult to replace, effective wastewater treatment is assured through the settling and storage of suspended solids, flow equalization, filtration and, if desired, chemical addition.  
           [0009]    Thus, upon the installation of the wastewater treatment unit of the present invention immediately downstream of a new or existing septic tank or an aerobic treatment unit, the following advantages are achieved:  
           [0010]    a) direct filtration and settling of treated wastewater or treated effluent,  
           [0011]    b) beneficial flow equalization through all upstream and downstream treatment stages,  
           [0012]    c) the addition of downstream chemicals via chemical feeders,  
           [0013]    d) the enhancement of beneficial nitrification, and  
           [0014]    e) the enhancement of beneficial de-nitrification.  
           [0015]    With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a cross sectional view of a wastewater treatment system, and illustrates a wastewater treatment unit defined by a wastewater treatment mechanism (Bio-Kinetic® device) housed within a sectional solids settling and retention basin having an inlet connected to a conventional wastewater treatment plant and an outlet connected to a pipe leading to a downstream soil absorption system, such as an irrigation system, a leaching tile field, sand filters, etc. with an upper end of the settling and retention basin being accessible above grade upon the removal of an access cover.  
         [0017]    [0017]FIG. 2 is an enlarged axial cross sectional view, and illustrates details of the wastewater treatment unit including compression clamps and associated seals or gaskets for securing tubular sections of the solids settling and retention basin to each other in a water-tight fashion, as well as securing the access cover to an uppermost tubular riser section of the solids settling and retention basin.  
         [0018]    [0018]FIG. 3 is a perspective view of the wastewater treatment unit, and illustrates the exterior configuration thereof including a plurality of circumferential outwardly projecting ribs (inwardly opening valleys) and outwardly opening valleys (inwardly projecting ribs) and the access cover in its seated position.  
         [0019]    [0019]FIG. 4 is an axial cross sectional view of the solids settling and retention basin of FIGS. 1 through 3, and illustrates three individual sections prior to being united together, a safety/surface guard or cover, and the access cover.  
         [0020]    [0020]FIG. 5 is an axial cross sectional view through a one-piece molded solids settling and retention basin body immediately after the molding thereof, and illustrates shaded areas representing annular bands of waste material which can be selectively removed to form a segmented solids settling and retention basin and its associated safety/service guard or cover.  
         [0021]    [0021]FIG. 6 is an axial cross sectional view of the segmented solids settling and retention basin body, and illustrates as exemplary the manner in which riser sections and/or ring sections can be interchangeably mated with each other.  
         [0022]    [0022]FIG. 7 is another axial cross sectional view of another one-piece solids settling and retention basin body, and illustrates as exemplary eleven shaded areas representative of annular bands of waste material which can be selectively removed and discarded and from which a solids settling and retention basin can be formed of a variable number of riser and/or ring sections differing in height from those of FIGS. 5 and 6.  
         [0023]    [0023]FIG. 8 is an axial cross sectional view of the solids settling and retention basin body of FIG. 7, and illustrates as exemplary all of the riser/ring sections telescopically united in one of several interchangeable arrangements.  
         [0024]    [0024]FIG. 9 is a highly enlarged axial cross sectional view of the encircled portion of FIG. 2, and illustrates a compression clamp and seal assembly formed by an annular sealing gasket interposed between telescopic tubular sections of the sectional solids settling and retention basin and the compression clamp clamping the sections together in a water-tight fashion.  
         [0025]    [0025]FIG. 10 is a top perspective view of the compression clamp, and illustrates opposite ends thereof, one end being in the form of a projecting tab or tongue having a plurality of elongated slots or openings, and the other end having an apertured wall or shoulder through which the tongue projects and a flexible locking tab having an inward projection which is received in one of the openings of the projecting tongue.  
         [0026]    [0026]FIG. 11 is an enlarged fragmentary longitudinal cross sectional view of the compression clamp of FIG. 10, and illustrates details of the opposite ends thereof including the inward projection which seats in one of the openings of the tongue.  
         [0027]    [0027]FIG. 12 is a fragmentary longitudinal cross sectional view of the compression clamp, and illustrates the compression clamp in its clamped position. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0028]    A novel wastewater treatment system constructed in accordance with this invention is illustrated in FIG. 1 of the drawings and is generally designated by the reference numeral  10 .  
         [0029]    The wastewater treatment system  10  includes a conventional wastewater treatment plant  11  connected by a discharge or outlet pipe  15  to a novel and unobvious wastewater treatment unit  20  of the present invention which is in turn connected by an outlet or discharge pipe  16  to a conventional soil absorption system or device  14 , such as an irrigation system, a leaching tile field, or the like. In conventional wastewater systems, the wastewater treatment plant  11  is connected directly by a sewer pipe to the soil absorption system  14 , obviously absent the wastewater treatment unit  20 , and as the total volume of solids are discharged and accumulate in the soil absorption system  14 , plugging and premature failure thereof is common. Removal of accumulated solids from a failed soil absorption system, such as the soil absorption system  14 , to rejuvenate the same is not technically feasible. However, in accordance with the novel method of this invention indefinitely extends the life of a new or rejuvenating such a failed soil absorption system  14  is accomplished by first excavating earth between the wastewater treatment plant  11  and the soil absorption system  14 . Thereafter the wastewater treatment unit  20  is installed as illustrated in FIG. 1 connected to the discharge of the wastewater treatment plant  11  through a newly installed outlet or discharge pipe  15  and by a newly installed outlet or discharge pipe  16  to the soil absorption system  14 .  
         [0030]    As will be described more fully hereinafter, the wastewater treatment unit  20  removes accumulated solids discharged therein from the wastewater treatment plant  11  through the pipe  15  and thus the liquid discharge from the wastewater treatment unit  20  via the discharge pipe  16  is substantially solids-free. Solids so removed by the wastewater treatment unit  20  can be periodically removed therefrom and thereby the life of the soil absorption system  14  is extended or rejuvenated.  
         [0031]    The wastewater treatment plant  11  is of a conventional construction and corresponds to the wastewater treatment plant disclosed in U.S. Pat. Nos. 5,207,896 and 5,264,120 granted respectively on May 4, 1993 and Nov. 23, 1993 to Norwalk Wastewater Equipment Company of Norwalk, Ohio, the assignee of the present invention. The specific details of the wastewater treatment plant of the latter-identified patents is incorporated herein by reference, but excluded from a clarifier or clarification chamber  17  of the wastewater treatment system  10  is the wastewater treatment mechanism (BioKinetic® device) and instead a conventional tubular tee T is connected to the pipe  15 .  
         [0032]    The wastewater treatment unit  20  (FIGS. 1 and 2) of the present invention includes a sectional solids settling and retention basin  21  which preferably is a one-piece body molded from polymeric/copolymeric synthetic plastic material, as shall be described more fully hereinafter with respect to FIGS. 5 and 7 of the drawings, or can be constructed from a plurality of individual tubular sections, such as an upper tubular section or riser  22 , an intermediate or middle tubular section  23  and a lower tubular section  24  closed by an integral bottom wall  25  collectively defining the solids settling and retention basin  21  and a solids settling and retention chamber  26  thereof in which solids entering the chamber  26  through the discharge pipe  15  from the wastewater treatment plant  11  accumulate and can be periodically removed. The discharge pipe  15  is solvent-connected to the intermediate section  23  by a conventional schedule 40 PVC inlet coupling  18  and an associated seal (not shown), and the discharge pipe  16  is likewise connected to the intermediate tubular section  23  by another schedule 40 PVC outlet coupling  19  and an associated seal (not shown).  
         [0033]    A wastewater treatment mechanism  50  (BioKinetic® device) which corresponds in most respects to the like numbered wastewater treatment mechanism of U.S. Pat. No. 5,264,120 is suspendingly supported within the solids settling and retention chamber  26  of the solids settling and retention basin  21 . The wastewater treatment mechanism  50  includes an outermost, substantially cylindrical, integral, one-piece molded filtering means, filtering media or filtering body  70  having a lower cylindrical filtering wall portion  72  of a smaller mesh than that of a upper cylindrical filtering wall portion  73  with an imaginary line  74  defining the line of demarcation therebetween. A solid wall  71  closes the bottom of the filtering means  70  and an upper end thereof terminates in a radially outwardly directed flange  75 .  
         [0034]    The filtering body  70  includes a pair of diametrically opposite flow equalization means  85  defined by vertically aligned spaced flow equalization ports  81 ,  82  and  83  progressively increasing in size upwardly and functioning in the manner set forth in U.S. Pat. No. 5,264,120. The sizes, spacing and function of the flow equalization ports  81  through  83  correspond to the same dimensions and functions as set forth in U.S. Pat. No. 5,264,120 which are incorporated hereat by reference.  
         [0035]    A housing  90  having an open bottom is closed by an upper closure assembly  120  suspendingly support therein a baffle plate assembly  110  housing approximately three dozen baffle plates  99 . The latter unitized components corresponding substantially in structure and function to the like components of U.S. Pat. No. 5,264,120. The upper closure assembly  120  also includes a top wall or deck having a generally T-shaped channel (not shown) which discharges liquid into an outlet port  176  slidably telescopically received in a tubular discharge pipe  453  of a first flange coupler  451  which is vertically slidably received downwardly into and upwardly out of a generally U-shaped upwardly opening flange receiving coupler  456  having an opening (unnumbered) in fluid communication with the discharge pipe  16 . The couplings or coupler  451 ,  456  permit the entire wastewater treatment mechanism  50  to be installed into and removed from the solids settling and retention basin  21  from above, as will be more apparent hereinafter.  
         [0036]    Means  140  in the form of a dry tablet chlorination feed tube  141  for housing stacked chlorination tablets is carried by the upper closure assembly  120  as is dechlorinating means  180  in the form of a dry tablet dechlorination feed tube  181  for housing stacked dechlorination tablets, again as the latter structures and their functions are more fully specified in U.S. Pat. No. 5,264,120.  
         [0037]    Resting atop the flange  75  of the wastewater treatment mechanism  50  is a removable moisture/vapor closure, cover or shield  55  defined by a one-piece molded polymeric/copolymeric body including a circular disc  51 , two tubular portions  57 ,  58  projecting upwardly therefrom, and a tubular handle portion  59  spanning the tubular portions  57 ,  58 . When positioned as illustrated in FIG. 2 of the drawings, the tubular portions  57 ,  58  of the moisture/vapor cover  55  telescopically receive and stabilize the respective chlorination and dechlorination tubes  141 ,  181 . Four equally circumferentially spaced holes (not shown) in the circular disc  51  receives fasteners, such as screws, which are threaded into like holes (also not shown) of the flange  75  to secure the moisture/vapor cover  55  to the flange  75  yet permit the rapid disassembly thereof by removing the screws (not shown). The purpose of the moisture/vapor cover or shield  55  is to prevent condensation from entering the wastewater treatment mechanism  50 .  
         [0038]    Before specifically describing the three piece sectional solids settling and retention basin  21  of FIG. 2 which is defined by the upper, intermediate and lower tubular sections  22  through  24 , respectively, reference is made to FIG. 5 of the drawings which illustrates a one-piece hollow solids settling and retention body  30  molded by rotational molding, vacuum molding or injection molding from polymeric/copolymeric plastic material, such as corrosion resistant polyethylene. The hollow body  30  includes a tubular wall  31  having an upper end closed by an integral top wall  32  and a bottom end closed by an integral bottom wall  40 . A plurality of alternating internally projecting peripheral ribs  33 ,  34  and inwardly opening valleys  35 ,  36  are disposed substantially along the axial length of the tubular body  31 . The ribs  33  are of a substantially lesser internal diameter than the diameter of the ribs  34  and the valleys  35  are of a greater axial height and a greater diameter than the axial height and diameter of the valleys  36 . For the most part, the ribs and the valleys are arranged in the axial sequence  33 ,  35 ,  34 ,  36 ;  33 ,  35 ,  34 ,  36 ; etc. Within each such sequence of ribs and valleys, each rib  33  and its adjacent valley  35  are defined by a wall  37  common to each rib  33  and each valley  35 . Each rib  33  also includes an innermost cylindrical wall portion  38  and each valley  35  adjacent thereto includes an outermost cylindrical wall portion  39 .  
         [0039]    Cut lines C 1 , C 2  define annular bands of scrap material or bands S 1 , S 2  and S 3 . By cutting along the cut lines C 1 , C 2 , the shaded annular bands S 1 , S 2  and S 3  are removed as scrap material and four tubular sections  41 ,  42 ,  43  and  44  are formed therefrom. Adjacent the top wall  32 , a somewhat wider circumferential band of scrap material S 4  can be removed when the hollow body  30  is severed along the cut lines C 1 , C 2  associated therewith. However, the hollow body  41  adjacent the top wall  32  terminates in two adjacent valleys  35 ,  35  separated by a rib  34 . The purpose of this configuration is to not only create the tubular section  41  of essentially the identical contour as the tubular sections  42 ,  43  and  44 , but also to form therefrom a generally concavo-convex wall  45  which can be rotated or flipped 180° from the position shown in FIG. 5 to that shown in FIG. 6 and thereby define a safety/surface guard, closure or cover  45 , preferably having a central hole  47 , for closing the solids settling and retention basin  21 , as is illustrated in its operative position in FIG. 2 and FIG. 6 of the drawings. However, upon the removal of the annular scrap  4 , the upper and lower edges (unnumbered) of the tubular sections  41  through  44  are identical to each other and a cylindrical wall portion  49  of each smaller valley  36  (FIG. 6) will telescopically seat within the remaining portion of the wall portion  39  of the larger valley  35  resulting in the telescopic nested supported relationship of the section  41  upon the section  42 , the section  42  upon the section  43 , and the section  43  upon the section  45 .  
         [0040]    The hollow body  30  and the manner in which the scrap S 1  through S 4  are removed therefrom is merely exemplary of many different options which are available with respect to a particular installation of the solids settling and retention basin  21  between the wastewater treatment plant  11  and the soil absorption system  14  (FIG. 1). For example, the hollow body  30  (FIG. 5) is of the same diameter as the diameter (approximately 24″) of the solids settling and retention basin  21  but is only 60″ in height, as compared to the approximately 70″ total height of the solids settling and retention basin  21 . If only the band of scrap S 4  was removed, the remaining uncut tubular sections  41  through  44  of the hollow body  30  could be used in lieu of the axially shorter lower tubular section  24  (FIG. 2) of the solids settling and retention basin  21  thereby increasing the overall height, volume, and depth below grade or grade level GL thereof. As another example, by removing all bands of scrap material S 1 -S 5 , each of the tubular sections  41  through  44  can be individually utilized to increase the height or depth below grade GL or both of the solids settling and retention basin  21  by, for example, adding one of the sections  41  through  44  to the upper tubular section or riser  22  (FIG. 2) or to the lower section  24  as a so-called ring. Depending upon the number of removed scrap bands S 1  through S 5 , the axial heights thereof and the distances therebetween, each 60″ hollow body  30  can be utilized at the site of installation as might be required. In FIG. 5, if all scrap or scrap sections S 1  through S 5  were removed from the areas indicated, the upper and lower tubular sections  41 ,  44  would each be approximately 12″ in axial length and the two middle tubular sections  42 ,  43  would each be approximately 18″ in length. These sections could be used, as desired, to alter the overall height and depth above and/or below grade GL of the solids settling and retention basin  21  by 12″, 18″, 24″ etc. increments.  
         [0041]    As another example of utilizing the hollow body  30  or sections thereof for particular installations, another identical hollow body  30 ′ is illustrated in FIG. 7 and the height thereof is also approximately 60″. However, in this case the hollow body  30 ′ includes eleven tubular scrap sections S 6  through S 16  which if all were removed would create ten tubular riser or ring sections  60  through  69 . The tubular sections  60  through  64  are each 6″ in axial height and the tubular sections  65  through  69  are each 3″ in axial height. Upon the removal of the cylindrical scrap material S 6  through S 16 , the tubular sections are shown in FIG. 8 telescopically united to each other, though such is merely exemplary and will not be used in actual practice. However, any 6″ tubular section  60  through  64  or any 3″ tubular section  65  through  69  can be utilized as need be to increase the height or depth above or below grade GL of the solids settling and retention basin  21  of FIG. 2 in lesser axial increments than provided by the 12″ tubular segments  41 ,  44  and the 18″ tubular segments  42 ,  43  of the body  30  of FIG. 5. Accordingly, the hollow body  30  and the equivalent hollow body  30 ′ demonstrate the flexibility afforded the solids settling and retention basin  21  for a variety of site installations. It is, of course, within the scope of the invention to remove, for example, only the scrap material S 4  or S 6  of the respective hollow bodies  30 ,  30 ′ and utilize the same as a single piece basin for other purposes, such as a pump housing. For example, a preferable single piece basin of approximately 70¼″ in height could be formed by molding either of the hollow bodies  30 ,  30 ′ of an approximate axial length of 72″. Thereafter, the removal of only the narrow scrap section S 4  of the hollow body  30  or the scrap section S 6  of the hollow body  30 ′ would form a one-piece molded basin of approximately 70¼″. The latter basin excludes the flat wall  98  but would be provided with openings corresponding to the openings O,  0 ′, though if used for a pump housing, the axial offset would be unnecessary.  
         [0042]    Reference is made to FIG. 4 of the drawings which more specifically demonstrates details of the intermediate or middle tubular section  23 , as compared to the upper tubular section  22 , the lower tubular section  24 , or any of the tubular sections  41  through  44  and  60  through  69 . The major difference is an inwardly projecting rib  95  (FIG. 4) having an innermost cylindrical wall portion  96  of a diameter less than the diameter of the ribs  33 ,  34  and an upper substantially horizontal wall portion  97 . The rib  95  projects inwardly substantially beyond the inward projection of any of the ribs  33 ,  34 , and this allows the wastewater treatment mechanism  50  to be inserted into and withdrawn from the solids settling and retention basin  21  through the open upper end (unnumbered) upon the removal of the safety/service cover  45  and a separately fabricated heavy duty access cover  46 . Since the flange  75  (FIG. 2) of the filter media body  70  of the wastewater treatment mechanism  50  has a diameter substantially greater than the opening defined by the cylindrical wall portion  96  of the rib  95 , the flange  75  is underlyingly supported by the horizontal wall portion  97  of the rib  95  of the tubular section  23 . Additionally, there is a considerable annular gap G (FIG. 2) between the solids settling and retention basin  21  and the filter body  70  of the wastewater treatment mechanism  50  which allows the entire filter body  70  to be shifted radially to the left, as viewed in FIG. 2, to withdraw the outlet port  176  from the tubular discharge pipe  453  and vice versa incident to disassembly and reassembly, respectively, for purposes of installation, inspection servicing and/or cleaning.  
         [0043]    The intermediate or medial tubular section  23  also includes two diametrically opposite relatively flat wall portions  98  having respective openings O, O′ (FIG. 2) preferably cut therein at the plant or factory immediately after the molding of the tubular section  23  or an entire one-piece basin  21 , as will be described more fully hereinafter. The inlet coupling  18  and the outlet coupling  19  are also preferably bolted (not shown) to the tubular section  23  at the factory. The axis Ao of the opening O (FIG. 2) is 1″ above the axis Ao′ of the opening O′ creating thereby an automatic and natural 1″ fall between the two openings O, O′.  
         [0044]    The upper tubular section  22  (FIG. 2), normally termed a “riser” in the trade, is clampingly secured to the intermediate tubular section  23  by a compression clamp and seal assembly  100 . In FIG. 2 an identical compression clamp and seal assembly  100  clamps the medial tubular section  23  to the lower section  24  and, of course, identical compression clamp and seal assemblies  100  are utilized to connect other upper tubular sections or risers as desired above the medial tubular section  23  and like tubular sections, which are normally termed “rings” in the trade, when added beneath the middle tubular section  23 . A like compression clamp and seal assembly  100  also clamps the heavy duty access cover  46  to the upper tubular section or riser  22  with a peripheral edge (unnumbered) of the safety/service cover  45  being sandwiched between wall portions (unnumbered) of the uppermost rib  34  of the tubular section  22  and an inwardly directed peripheral wall  91  (FIGS. 2, 4 and  6 ) of an outwardly directed rib  92  of the heavy duty access cover  46 .  
         [0045]    The compression clamp and seal assembly  100  is best illustrated in FIG. 9 of the drawings, and includes an O-ring type annular seal  105  and a compression clamp  115 . The annular seal  105  includes an outer cylindrical leg portion  106 , a bight portion  107 , and an inner cylindrical leg portion  108  collectively defining therebetween a slot or groove  109  which receives the wall portion  39  of the lower tubular section  24 . A generally radially inwardly directed wall portion  101  of the annular seal  105  is sandwiched between opposing generally radial wall portions  102 ,  103  of the intermediate tubular section  23  and the lower tubular section  24 , respectively. A number of conventional annular sealing lips (unnumbered) are carried by the wall portions  108 ,  101 .  
         [0046]    The compression clamp or clamping means  115  of the compression clamp and seal assembly  100  is a one-piece molded polymeric/copolymeric band of a substantially U-shaped configuration over a major portion of the length thereof from a first end portion  112  to an opposite second end portion  113  at which a minor portion  114  continues in the form of a tongue or tab having a plurality of equally spaced narrow slots  119  and a tool receiving opening  116 . The end portion  112  of the major portion includes an upstanding wall  117  (FIG. 11) having a slot  118  and adjacent to the latter a depending flexible latching tab  125  carries a projection  121 . The flexible latching tab  125  is bordered by a U-shaped slot  124 . A slot  128  is formed through the flexible locking tab  125 . The first end portion  112  further includes a group of equally spaced slots  121  and an upstanding locking tab  122  having an opening  123 .  
         [0047]    After the annular seal  105  has been assembled upon the wall portion  39  in the manner illustrated in FIG. 9, the upper tubular riser section  23  is seated upon the sealing lips (unnumbered) of the radial wall portion  101  of the annular seal  105  after which the compression clamp  115  is positioned in loosely surrounding relationship thereto, as is also illustrated in FIG. 9 of the drawings. The tongue  114  of the compression clamp  115  is inserted through the slot  118  (FIG. 12) and over and beyond the locking tab  122 . A tool, such as a screwdriver, is then inserted through the tool receiving opening  116  or any one of the slots  119  and the end of the blade thereof is seated in a selected one of the slots  121  of the first end portion  112  of the compression clamp  115  after which the screwdriver is levered or fulerumed in a conventional manner to draw the tongue  114  further through the slot  118  and further over and further beyond the locking tab  122  which progressively constricts the compression clamp  115  against the outer cylindrical leg portion  106  (FIG. 9) of the annular seal  105  eventually creating a water-tight seal therebetween and a water-tight seal between the sealing lips (unnumbered) and the opposing wall portion  39  of the valley  36 . When the compression clamp  115  is tightened manually in this fashion sufficiently to assure a water-tight seal, the tongue  114  is manipulated as need be by utilizing the screwdriver to align one of the slots  119  of the tongue  114  with the locking tab  122  and subsequently uniting the two together in the manner illustrated in FIG. 12 at which point the locking tab or projection  122  projects through one of the slots  119 , as is illustrated in FIG. 12. If desired a lock, bolt, locking ring or a wire can be passed through the opening  123  of the locking tab  122  and thereafter twisted to preclude inadvertent/accidental disassembly of the locking tab  122  from its assembled condition (FIG. 2).  
         [0048]    The compression clamp  115  performs a number of functions effectively, such as compressing the annular gasket  105  to effect a water-tight seal between any two components, preventing vertical separation between components, maintaining horizontal alignment of the components, and creating in effect two seals, one afforded by the inner cylindrical leg portion  108  and the other by the radially inwardly directed wall portion  101  of the annular seal or gasket  105 . The latter assures a water-tight seal between all tubular sections and between the uppermost tubular section or riser  22 , the associated safety/service cover  45  thereof, and the heavy duty access cover  46 . The latter two covers  45 ,  46  are also preferably tether-connected to the upper tubular section or riser  23  by respective retainer cables  145 ,  146 , respectively (FIG. 2).  
         [0049]    The compression clamp  115  is released and removed by first releasing and removing the locking ring or twisted wire passing through the opening  123 . Thereafter the end of the tongue  114  adjacent the slot  116  can be manually gripped or gripped by a pair of pliers and pulled upwardly to remove locking tab  122  from its associated slot  119 . At this time the flexible latching tab  125  is still engaged in its associated slot  119  (FIG. 12) and further lifting of the tongue  114  upwardly will have no effect thereon. A blade of the screw driver is inserted through the slot  128  with its end engaged against the underlying upper surface (unnumbered) of the first end portion  112 , and thereafter the blade is pivoted or torqued to the right, as viewed in FIG. 12, causing the flexible latching tab  125  to flex to the phantom outline position of FIG. 12 which draws the depending latching projection  121  outwardly of its associated slot  119  thereby completely releasing the compression clamp  115 .  
       Installation  
       [0050]    Reference is made to FIG. 1 of the drawings, and it is assumed for the moment that the wastewater treatment unit  20  has not been installed and that a single pipe or sewer pipe extends from the wastewater treatment plant  11  to the soil absorption system  14  which has become “plugged” through the retention of solids, as described earlier herein, thereby potentially causing a back-up of sewage into an associate home (not shown). The soil absorption system  14  is considered “failed” and “rejuvenation” of a “failed” soil absorption system  14  is not technically feasible, except at the considerable inconvenience, danger and expense earlier noted. However, in keeping with the present invention, the site at which the waste treatment unit  20 , and particularly the solids settling and retention basin  21 , is to be installed is first excavated by simply digging a hole to expose the existing sewer line or pipe (not shown). A relatively narrow sewer trench is dug along the length of the original sewer line to enable its entire removal. A hole must also be dug or excavated for the solids settling and retention basin  21 . Since the maximum outside diameter of the solids settling and retention basin  21  is approximately 24″, the excavation should be at a minimum of 36″×36″ square or approximately 36″ diameter, if round. The exact excavation depth depends upon a variety of factors and of importance is the vertical distance between grade or grade level GL and the outlet (unnumbered) of the clarifier  17  from which the old sewer line is removed and replaced by the outlet pipe  15 . The closer the outlet pipe  15  to grade level GL, the less the depth of the excavation and vice versa. One or more risers of required heights might necessarily have to be added above the middle tubular section  21 , while one or more rings of required heights might necessarily have to be added below the middle tubular section  21  depending upon the specifics of the installation. As a typical example, the excavation for the solids settling and retention basin  21  is preferably deep enough to permit a minimum 4″ levelling bed or pad P of gravel, sand or fine crushed stone upon which rests the bottom wall  25  of the solids settling and retention basin  21 . In actual practice and in the present example the distance D 1  between the upper edge (unnumbered) of the upper tubular section or riser  22  (FIGS. 1 and 2) and the bottom wall  25  is approximately 70¼″ and the distance D 2  from the top of the heavy duty access cover  46  and grade level GL is approximately 7½″. Thus the total depth of the excavation would be approximately 75″ to 80″ depending upon the total thickness or depth of the leveling pad P.  
         [0051]    The new outlet pipe (influent sewer line)  15  is then connected to the clarifier opening (unnumbered) of the wastewater treatment plant  11 , though not permanently connected thereto. The outlet pipe (effluent sewer line)  16  can be positioned in the sewer trench, generally as illustrated in FIG. 1, though not necessarily permanently connected to the soil absorption system  14 . The distance between the top surface of the leveling pad P and the center of the pipe  15  is measured to assure that the inlet coupling  18 , previously bolted to the flat wall portion  98  of the tubular section  23 , will be in axial alignment with the pipe  15 . Obviously, the axis of the pipe  15  must be preferably 1″ minimum above the axis of the pipe  16  upon the complete installation of the wastewater treatment unit to assure that the pipes  15 ,  16  are aligned with and enter into the couplings  18 ,  19  which are of the same 1″ fall because of the 1″ difference in the axes Ao and Ao′ earlier described. In the specific example given the lower tubular section  24  of the solids settling and retention basin  21  is selected and, for example, formed by selectively removing scrap material from several of the molded basin bodies  30  such that when clamped to the middle tubular section  21  and installed with the bottom wall  25  resting upon the levelling pad P, the total distance D 3  from the bottom wall  25  to the volute (bottom) of the pipe  15  is approximately 38⅛ and the distance D 4  of the volute (bottom) of the pipe  16  from the bottom wall  25  of the solids settling and retention basin  21  is 37⅛″ which is a natural 1″ fall between the two.  
         [0052]    The solids settling and retention basin  21  is then lowered into the excavation with its bottom wall  25  seated upon the upper surface of the levelling pad P after which the pipe  15  can be inserted into and solvent-welded to the coupling  18 . An appropriate conventional seal is provided between the outlet pipe  15  and the wall (unnumbered) of the wastewater treatment plant  11 . The pipe  16  is likewise inserted into and solvent-welded to the coupling  19  and to the soil absorption system  14 . Prior to making the latter permanent connections, a level is applied to the solids settling and retention basin  21  to assure horizontal level and vertical plum thereof.  
         [0053]    The solids settling and retention basin  21  should be back-filled immediately after the pipes  15 ,  16  have been permanently installed. The sewer trench above the pipes  15 ,  16  should also be back-filled. However, before back-filling the heavy duty access cover  46  should be at least seated upon, though not necessarily locked to the riser  22  to prevent dirt or debris from entering the solids settling and retention basin  21  during back-filling. The finished grade GL should be  3 ″ below the upper edge (unnumbered) of the solids settling and retention basin  21 .  
         [0054]    Immediately after back-filling, the access cover  46  is removed and the solids settling and retention basin  21  is filled with hold down water, although the hold down water can be added before back-filling.  
         [0055]    The filtering body  70  of the wastewater treatment mechanism  50 , excluding the housing  90 , the upper closure assembly  120 , the baffle plate assembly  110  carried by the upper closure assembly  120 , the chlorination feed tube  141 , the dechlorination feed tube  181 , the moisture/vapor shield or cover  55  and the safety/service cover  45 , is lowered into the solids settling and retention basin  21 . Natural buoyancy created by the hold down water will cause the filtering body  70  to tend to float in the hold down water, but a hose can be utilized to direct water into the filtering body  70  through the open upper end thereof resulting in the gradual sinking of the filtering body  70  into the solids settling and retention basin  21 . During the latter assembly the filtering body  70  is aligned such that the flange coupler  451  (FIG. 2) progressively vertically enters into and seats in the U-shaped receiving flange or coupling  456  (FIG. 2). In the final installed position of the filtering body  70  the flange  75  thereof rests upon the rib  95  of the solids settling and retention basin  21 . Means (not shown) may be utilized to secure the flange  75  upon the rib  95 , as, for example, four circular discs equally spaced about the periphery of the flange  75  and vertically pivotally mounted thereto in an eccentric fashion such that each disc can be rotated in a horizontal plane about a vertical axis from a position entirely inside the periphery of the flange  75  to a radially outwardly projecting position with a portion of each disc being received within the opposing valley and underlying the uppermost rib of the solids settling and retention basin  21  thereby preventing vertical withdrawal of the filtering body  70  therefrom.  
         [0056]    Thereafter the unitized housing  90 , the upper closure assembly  120 , and the baffle plate assembly  110  suspendingly supported from the latter are inserted progressively into the filtering body  70  until the outlet port  176  is aligned with the tubular discharge pipe  453  of the first flange coupler  451  after which the housing  90  is shifted to the right to the position illustrated in FIG. 2.  
         [0057]    The moisture/vapor shield or cover  55  is positioned atop the flange  75  and is conventionally secured thereto by passing fasteners through openings (not shown) in the circular disc  51  of the safety/service guard or cover and threading the same into the flange  75  of the filtering body  70 . The chlorination tube  141  and the dechlorination tube  181  are telescopically assembled through the tubular portions  57 ,  58 , respectively, to the position illustrated in FIG. 2. Chlorination tablets are inserted in the chlorination tube  141  and dechlorination tablets are inserted into the dechlorination tube  181  before or after the latter installation with caps (unnumbered) being appropriately assembled thereon. The safety/service guard or cover  45  and the heavy duty access cover  46  are then assembled, as shown in FIG. 2, and locked by means of the associated compression clamp and seal assembly  100 .  
       Operation  
       [0058]    Under normal conditions, wastewater W (FIG. 1) within the clarification chamber or clarifier  17  of the wastewater treatment plant  11  is at a wastewater level L dependent upon the hydraulic head, and the rate of flow of the wastewater/effluent through the wastewater treatment unit  20  and particularly the wastewater treatment mechanism  50  thereof will depend upon the head or height of the wastewater within the clarification chamber  17 . During such normal hydraulic head, the level L of the wastewater approximates the position of the lowermost of the diametrically opposite pair of flow equalization ports or openings  81 , and this is the design flow level DFL of the wastewater treatment unit  20 , as established by the flow equalization ports  81  of the wastewater treatment mechanism  50 . Under such normal design flow conditions, wastewater not only accumulates in the solids settling and retention basin  21 , but small solids or particles Ss (FIG. 2) pass through the smaller mesh of the lower cylindrical filtering wall portion  72  while larger solid particles Sp falling downwardly and accumulating upon and above the bottom wall  25  of the solids settling and retention basin  21 . The wastewater and still smaller particles Sss which have passed through the filtering wall portion  72  but are too light to settle upon the bottom wall  71  of the filtering body  70  flow upwardly and through the baffle plate assembly  110  during which the smallest particles are filtered out from the wastewater by the baffle plates  99 . The wastewater eventually discharges through an opening (not shown) in the upper closure assembly  120  and passes through the outlet ports  176 ,  453  into the pipe  16  with prior chlorination and dechlorination being effected, if desired, in the manner disclosed in U.S. Pat. No. 5,264,120. In the case of a retro fit for a failing or failed disposal system, the essentially solids-free wastewater/effluent continues toward its discharge at the soil absorption device  14  which though plugged can absorb and disperse the substantially solids-free effluent thereby rejuvenating the entire wastewater treatment system  10  due to the extraction of the solids or solid particles Sp, Ss, Sss and Spl within the solids settling and retention basin  21 , the bottom wall  71  and within and upon the approximately three dozen baffle plates  99  of the baffle plate assembly  110 . Should the installation be for a new wastewater treatment system, the substantial solids-free effluent extends the life of the disposal system substantially indefinitely.  
         [0059]    Should the flow of wastewater from the clarification chamber  17  exceed the design flow designated by the design flow level DFL (FIG. 2), as controlled by the diametrically opposite flow equalization ports  81 , the wastewater will rise to a higher sustained flow level SFL at which the pair of flow equalization ports  82  become operative, as described in U.S. Pat. No. 5,264,120.  
         [0060]    During peak flow of wastewater from the clarification chamber  17 , the wastewater reaches a peak flow level PFL established by the larger diameter flow equalization ports  83 , just as in the case of U.S. Pat. No. 5,264,120 with, of course, solids or solid particles Spl passing through the larger mesh of the upper cylindrical filtering wall portion  73  and settling down and upon the bottom wall  71  of the filtering body or filtration media body  70 .  
       Servicing and Cleaning  
       [0061]    Access to the interior of the wastewater treatment unit  20  is required from time-to-time during normal use and is readily effected by removing the compression clamp  115  associated with the access cover  46 . Upon unlatching and removing the compression clamp  115 , the access cover  46  and the safety/service cover  45  can be removed. The chlorination and dechlorination tubes  141 ,  181  can simply be filled with tablets or can be removed by pulling the same vertically upwardly. Each tube  141 ,  181  can be flushed and cleaned, refilled with chlorination and dechlorination tablets, and reassembled to the position illustrated in FIG. 2 after which the components  45 ,  46  and  115  can be reassembled. Obviously the feed tubes  141 ,  181  need not be removed when the only servicing required is to add respective chlorination and dechlorination tablets thereto.  
         [0062]    Over longer periods of time the entire wastewater treatment unit  20  must be completely cleaned to remove all of the solids accumulated in the solids settling and retention basin  21 , all of the solids accumulated upon the bottom wall  71  of the filtering body  70  and all of the solids accumulated upon each of the baffle plates  99  of the baffle plate assembly  110 . Such servicing is again accomplished by first removing the uppermost compression clamp  115 , the access cover  46  and the safety/service cover  45 . The feed tubes  141 ,  181  are then withdrawn upwardly and removed followed by the removal of the moisture/vapor shield or cover  55  after unfastening the cover disc  51  from the flange  75  of the filter media body  70 .  
         [0063]    The entire housing  90  of the wastewater treatment mechanism  50  can now be lifted upwardly by, for example, manually grasping the closure assembly  120  or utilizing a special tool (not shown) which interlocks with the upper closure assembly  120 . Since the baffle plate assembly  110  is secured to the upper closure assembly  120 , the unitized components  90 ,  110 ,  120  are removed in unison. The unitized components  90 ,  110 ,  120  must, of course, be lifted straight up, as viewed in FIG. 2, to remove the outlet port  176  from the discharge pipe  453  prior to lifting and removing components upwardly and outwardly from the filter media body  70 .  
         [0064]    The flange  75  of the filter media body  70  is then detached from the solids settling and retention basin  21  by rotating the eccentrically mounted, vertically pivoted, four circular discs in a horizontal plane (not shown and earlier described) to remove the same from the opposing valley which is the uppermost unnumbered valley of the middle tubular section  23  of the solids settling and retention basin  21 . The solids settling and retention basin  21  can then be lifted vertically upwardly to detach the couplings  451 ,  456 . A suction hose/line can be inserted into the filtering body  70  to withdraw wastewater and solids therefrom prior to lifting the filtering body  70  upwardly and outwardly of the solids settling and retention basin  21  to ease the effort involved in this task. The same suction line can then be inserted into the solids settling and retention basin  21  to draw wastewater and the solids accumulated therein while simultaneously washing and cleaning the interior of the solids settling and retention basin  21  utilizing water from a garden hose until the solids settling and retention basin  21  is thoroughly cleansed and rinsed. Thereafter, the safety/service cover  45  can be temporarily seated in the upper end of the riser  22  to preclude dirt or debris from entering the now cleaned solids settling and retention basin  21  while cleansing the withdrawn remaining components in the immediately environs. Water from a garden hose is directed to all surfaces of all of these components including the individual baffle plates  99  upon disassembly thereof from the baffle plate assembly  110  in the manner disclosed in U.S. Pat. No. 5,264,120.  
         [0065]    After all components have been thoroughly cleaned, they are reassembled in a manner apparent from the description of the disassembly thereof, with, of course, chlorination and dechlorination tablets being added to the respective feed tubes  141 ,  181  before or after the reassembly thereof. The moisture/vapor cover  55 , the safety/service closure  45 , the access cover  46  and the compression clamp  115  are reassembled in the manner shown in FIG. 2, and the wastewater treatment unit  20  is ready for continued long term wastewater treatment/disposal.  
         [0066]    It is to be particularly understood that though the solids settling and retention basin  21  of FIGS. 1 and 2 is sectional, the same can and for the most part will remain as a one-piece molded body as aforesaid with the openings O, O″ being cut therein at the factory to make certain that the axis Ao is 1″ higher than the axis Ao′ of the opening O′ thereby assuring the necessary natural 1″ fall to achieve efficient flow-through from the pipe  15  to the pipe  16 . Also, with the connectors  18 ,  19  being bolted to the wall portions  98  at the factory, when the one-piece solids and retention basin  21  is delivered to the site for installation, the only major criteria required for proper flow-through is to make certain that the discharge pipe  15  has an acceptable fall from the wastewater treatment plant  11  to the opening O and additional fall from the opening O′ to the soil absorption system  14 .  
         [0067]    Also though the invention has been described specifically with respect to the installation of the wastewater treatment unit  20  relative to an existing wastewater treatment plant  11  and a plugged soil absorption system  14 , the wastewater treatment plant  11  is equally applicable to “new” installations. In the case of a new installation, an area of the ground must be excavated to also include the new wastewater treatment plant  11  and, of course, a new soil absorption system  14  is installed. Obviously, there are no pre-existing sewer pipes to remove and, therefore, the installation remains essentially identical for the new system as that earlier described for the “old” or “plugged” system.  
         [0068]    Although a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the apparatus without departing from the spirit and scope of the invention, as defined the appended claims.