Patent Publication Number: US-7221282-B1

Title: Wireless wastewater system monitoring apparatus and method of use

Description:
BACKGROUND OF THE INVENTION 
   1. Incorporation by Reference 
   Applicant hereby incorporates herein by reference any and all U.S. patents and U.S. patent applications cited or referred to in this application. 
   2. Field of the Invention 
   This invention relates generally to fluid level monitoring devices, and more particularly to wireless wastewater system monitoring devices. 
   3. Description of Related Art 
   A municipal sanitary wastewater system is designed to transport waste material for the community. Spillage of waste material is of major concern to the system operator, the municipality, and the ratepayers in the community. Accordingly, these concerns have led to increasing environmental regulations and resultant penalties for sewer overflows. 
   As a result, efforts have been made in the art to semi-automate and automate the monitoring of wastewater systems as a means of early detection of sewage backups and rising sewage levels in the hopes of correcting such conditions before sewage overflows occur. In doing so, numerous difficulties have been encountered and heretofore not optimally addressed. Generally, the monitoring device, which essentially includes a sensor, a processor, a wireless transceiver, and a power supply, is installed within a manhole of a wastewater system so as to monitor the wastewater level and report an overflow condition through a wireless alarm transmission. Inherently, the monitoring device is exposed to the contaminating and corrosive environment of the wastewater system, often leading to premature failures of the devices. Further, by locating the monitoring device in the manhole of the wastewater system, additional difficulties are encountered in attempting to get the wireless signal out of the manhole, as the signal is attenuated or interfered with primarily by the iron manhole cover. Often, to overcome the signal attenuating effects of the manhole, a stronger signal from the monitoring device is required, leading to increased device costs, power consumption, and even wireless airtime. 
   The following art defines the present state of this field: 
   U.S. Pat. No. 3,735,638 to Miller is directed to a liquid level measurement device relying upon the principle of a resistance bridge wherein the height sensing means is one resistor of the bridge. The height sensing resistor is comprised of a fine wire extending from the bridge circuit to a grounding rod. The fine wire extends generally parallel to, but spaced from, the grounding rod in order to constitute the height sensor. In use, the height sensor is inserted in the liquid whose height is to be measured in such a way that the grounding rod and the fine wire extend generally perpendicular to the liquid level line. Thus, the aqueous ionic media whose height is being measured will short out that portion of the fine wire below the liquid level to decrease the effective resistance of the height sensor. This has the effect of unbalancing the bridge circuit to give a reading on a meter that is an indication of the height of the liquid. 
   U.S. Pat. No. 4,136,561 to Mueller et al. is directed to a control module having circuitry for generating control and timing signals and for receiving digital data. A plurality of sensor modules are connected to the control module and each contains devices for sensing various physical characteristics, such as water level, rainfall or the like. In response to control signals generated by the control module, each of the sensor modules is operable to input digital data representative of the sensed physical characteristics to the control module. A recorder is connected to the control module and includes a removable recording cassette for recording the digital data transmitted from the sensor modules. The recorder also records the identification of the sensor module transmitting data, along with the calendar day and the time of day that the data was transmitted. 
   U.S. Pat. No. 4,335,606 to Michalak is directed to an apparatus for measuring the level of at least one fluid and includes an elongated transparent tubular member open at both ends, one of the ends being vertically insertable into the fluid to a reference point below the fluid surface to establish a column of the fluid in the tubular member having a length generally equal to the distance between the reference point and the fluid surface, a stiff tether slightly longer in length than the tubular member and threaded therethrough, a plug connected to one end of the tether for closing at least the inserted end of the tubular member prior to withdrawing it from the fluid to contain the column of the fluid in the tubular member for measurement after the tubular member is withdrawn from the fluid, and a grip connected to the other end of the cable for remotely controlling the plug to close the inserted end of the tubular member. In the process of measuring the fluid level, the column of the fluid can be viewed through the tubular member to check for abnormalities in the fluid and the presence or absence of other immiscible fluids. 
   U.S. Pat. No. 5,608,171 to Hunter et al. is directed to a distributed, unattended wastewater monitoring system that uses advances in low-energy signal processing and distributed microelectromechanical systems and that involves wireless interrogation of distributed, low-power, normally-off sensors. In a preferred embodiment, a plurality of flowmeter stations and at least one rain gauge station are networked through a base station for storm water discharge of infiltration-inflow monitoring. Wireless transceivers are used to transmit radio signals into and out of a sewer manhole. 
   Japanese Patent App. No. JP 2002/054167 to Pentafu et al. is directed to a remote monitor for a manhole provided with a sensor part installed in the manhole within the area of a cellular phone network, a data logger part whereinto a measured value from the sensor part is input, a communication device part for emitting the data from the logger part as an electromagnetic wave, a power source part for driving the sensor part, the logger part and the device part, and a central processing part for receiving the electromagnetic wave from the device part through the network. The device part and the source part are housed in the storage part, installed below a cover body of a manhole cover having a through hole closed by the cover body, the cover body eliminating the interception of the electromagnetic wave. 
   U.S. Pat. No. 6,507,686 to Heinz et al. is directed to a cable network with a light waveguide cable which is introduced in the pipeline of an existing pipeline system. The light waveguide cable is arranged along a line, preferably at the vertex of the pipeline, and is provided with a protective layer so that a smooth transition exists between the wall surfaces of the pipeline and the cable. 
   Japanese Patent App. No. JP 2003/074081 to Megumi et al. is directed to a remote monitoring device provided with a battery, an opening-closing detecting switch for operating according to opening-closing of a manhole cover, a power supply unit for starting power source supply from the battery by operation of the opening-closing detecting switch and stopping the power source supply by receiving a power supply stopping signal, a controller for starting operation by the power source supply by the power supply unit and outputting transmission data including information capable of specifying a manhole, a communication unit having a transmission circuit for starting operation by the power supply unit and transmitting the transmission data from the controller to a management center via an antenna, and a receiving circuit for receiving the signal from the management center via the antenna and transmitting the power supply stopping signal to the power supply unit. 
   U.S. Patent App. No. US 2003/0192379 to Ridenour et al. is directed to an apparatus and a method for monitoring a liquid level in a 4–20 mA closed loop system. A process instrument and a measuring unit are powered for a predetermined time and power is provided by a battery. 
   The prior art described above teaches a liquid level measurement device, an apparatus for automatically sensing and recording data in a sewage system, an apparatus and method for measuring fluid, a distributed, unattended wastewater monitoring system, a remote monitor for manhole, a cable network with light waveguide cable for installation in pipelines of existing supply line systems, a remote monitoring device of manhole, and a water well monitoring system, but does not teach a wireless wastewater system monitoring apparatus wherein the processor/transceiver unit is located outside of the wastewater system or wherein the fluid level sensor&#39;s microprocessor is continuously powered while the processor/transceiver unit is only powered and a wireless signal sent when an overflow condition in the wastewater system is detected. The present invention fulfills these needs and provides further related advantages as described in the following summary. 
   SUMMARY OF THE INVENTION 
   The present invention teaches certain benefits in construction and use which give rise to the objectives described below. 
   The present invention is directed to a wireless wastewater system monitoring apparatus generally comprising a processor/transceiver unit, housed within a synthetic protective enclosure formed outside of the wastewater system, and a fluid level sensor configured to send an overflow signal to the processor/transceiver unit when an overflow condition in the wastewater system is detected. The processor/transceiver unit is configured with at least one microprocessor wired between the sensor and a power supply and with a transceiver so as to detect the overflow signal from the sensor and, in response, transmit a wireless alarm signal. The processor/transceiver unit is further configured such that only a portion of its circuitry is constantly powered so as to continuously monitor the sensor, while the remainder of its circuitry, including the transceiver, is only powered and a wireless signal sent from the unit when an overflow condition is detected or a routine status-check is being conducted. In one exemplary embodiment, the processor/transceiver unit includes two microprocessors, a first that is “always on” and a second that is “powered up” in response to an awake signal from the first and that then powers up and controls the transceiver. In a second exemplary embodiment, a single microcontroller having a standby clock mode and a normal clock mode achieves the minimal “always on” and responsive “powered up” function of the processor/transceiver unit. The enclosure within which the processor/transceiver unit is housed may be a lined hole adjacent to a manhole or an above-ground container. By locating the processor/transceiver unit outside of the wastewater system, and particularly a manhole, the unit is protected from the harmful, corrosive effects of the wastewater system and is able to transmit wireless signals more reliably and with relatively less power by avoiding the attenuating effects of the manhole cover. 
   In use, the processor/transceiver unit is positioned within the protective enclosure and the fluid level sensor is located in the wastewater system at a selected height above the normal fluid level. The processor/transceiver unit defaults to a standby mode in which the sensor is continuously powered by the power supply and monitored under the control of the microprocessor, while the other components of the processor/transceiver unit, including the transceiver, are not powered. When the fluid level rises and an overflow condition is detected, the sensor sends an overflow signal to the microprocessor of the processor/transceiver unit. In response to the overflow signal, the microprocessor then “awakens” the rest of the processor/transceiver unit and transmits a wireless alarm signal via the transceiver. The alarm signal, which contains information related to the location of the overflow condition, is routed through a wireless carrier to a network operations center for notification to the appropriate district operator for corrective action. Once the overflow condition has been corrected, a reset signal is transmitted to the district operator again through the wireless carrier and network operations center. The microprocessor may also be programmed to awaken at routine intervals and perform a status-check of the processor/transceiver unit, including verification of the remaining battery life, and send a status-result signal to the network operations center. The alarm, reset and status-result signals may be compressed before being transmitted by the processor/transceiver unit and decompressed upon receipt at the network operations center, thereby further reducing wireless airtime. By only powering up the entire processor/transceiver unit when an overflow condition has been detected or a routine status-check is being conducted, power consumption and wireless airtime are further minimized. 
   A primary objective of the present invention is to provide an apparatus and method of use of such apparatus that provides advantages not taught by the prior art. 
   Another objective is to provide such an invention capable of reducing the exposure of the wastewater system monitoring device processor/transceiver unit to the corrosive and contaminating effects of the wastewater system. 
   Yet another objective is to provide such an invention capable of reducing the attenuation of the wireless signals transmitted to and from the wastewater system monitoring device processor/transceiver unit. 
   A further objective is to provide such an invention capable of locating the wastewater system monitoring device processor/transceiver unit outside of the wastewater system. 
   Another objective is to provide such an invention capable of reducing the power consumption by the wastewater system monitoring device. 
   A still further objective is to provide such an invention capable of continuously monitoring the wastewater levels in the wastewater system while only selectively powering the other components of the wastewater system monitoring device. 
   Another objective is to provide such an invention capable of reducing the total wireless airtime used by the wastewater system monitoring device. 
   A still further objective is to provide such an invention capable of continuously monitoring the wastewater levels in the wastewater system while only selectively sending a wireless signal from the wastewater system monitoring device processor/transceiver unit. 
   Yet a still further objective is to provide such an invention capable of compressing and decompressing the wireless signals. 
   Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings illustrate the present invention. In such drawings: 
       FIG. 1  is a sectional schematic of an exemplary embodiment of the invention; 
       FIG. 2  is a sectional schematic of an alternative exemplary embodiment of the invention; 
       FIG. 3  is an enlarged partial sectional schematic of the exemplary embodiment of the invention shown in  FIG. 1  taken from circle “ 3 ”; 
       FIG. 4  is an electrical schematic of an exemplary embodiment of the invention; 
       FIG. 5  is an electrical schematic of an alternative exemplary embodiment of the invention; and 
       FIG. 6  is a system schematic of the exemplary embodiment of the invention shown in  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The above-described drawing figures illustrate the invention in at least two of its preferred embodiments, which are further defined in detail in the following description. 
   The present invention is directed to a wireless wastewater system monitoring apparatus  10  generally comprising a processor/transceiver unit  20  housed within an enclosure  60 , which is formed outside of the wastewater system  100 , and connected to a fluid level sensor  80  configured to send an overflow signal to the processor/transceiver unit  20  when an overflow condition in the wastewater system  100  is detected. The processor/transceiver unit  20  is configured with at least one microprocessor  22  wired between the sensor  80  and a power supply  24  and a transceiver  26  so as to detect the overflow signal from the sensor  80  and, in response, transmit a wireless alarm signal, as explained in more detail below. It will be appreciated by those skilled in the art that by locating the processor/transceiver unit  20  outside of the wastewater system  100 , and particularly a manhole  102 , the processor/transceiver unit  20  is protected from the harmful, corrosive effects of the wastewater system  100  and is able to transmit wireless data more effectively. As such, it will be further appreciated that while specific exemplary embodiments of the wireless wastewater system monitoring apparatus  10  are shown and described, numerous other configurations are possible without departing from the spirit and scope of the invention. 
   Turning to  FIG. 1 , in an exemplary embodiment of the wireless wastewater system monitoring apparatus  10  of the present invention, the enclosure  60  is essentially a vertical unit hole  62  formed in the ground  120  adjacent to the manhole  102 . In the case of a manhole  102  formed in a roadway, as shown, the unit hole  62  is dug through the finished road grade  122  and into the substrate  124  below. In the exemplary embodiment, the unit hole  62  is approximately 6–8″ in diameter and approximately 18–20″ deep and is located approximately 24–36″ from the manhole  102 . Again, it will be appreciated that various other sizes and locations of the unit hole  62  are possible in the present invention and that the embodiment shown and described is merely exemplary. Essentially, the unit hole  62  is configured to house and protect the processor/transceiver unit  20  outside of the wastewater system  100 . A cover  64  is installed over the unit hole  62  to securely enclose the processor/transceiver unit  20 . The cover  64  is formed of a non-metal, synthetic material such as a composite nylon so as to minimize interference with wireless signal transmission from the processor/transceiver unit  20 . A corrosion-resistant liner  66  also made of a synthetic material such as fiber-reinforced nylon may be installed within the unit hole  62  so as to further protect the processor/transceiver unit  20  and form a secure, moisture-tight seal with the cover  64 . The cover  64  may be removably secured to the liner  66  employing any technique such as a threaded, snap-fit or tongue-and-groove arrangement now known or later developed in the art. A gasket or o-ring (not shown) may be further employed in effectuating a water-tight seal. Both the cover  64  and the liner  66  together thus form a caisson-type enclosure  60  that is water-tight and that meets all applicable UL, NEMA and DOT standards. With the enclosure  60  so formed, the processor/transceiver unit  20  is placed within the unit hole  62  and the cover  66  is secured in place. In the exemplary embodiment, the sensor  80  is a float-type, mechanical switch sensor located within the manhole  102  and connected to the processor/transceiver unit  20  via an electrical cable  28 . To accommodate this arrangement, once the unit hole  62  is formed, a substantially horizontal cross-hole  70  is then formed so as to communicate between the unit hole  62  and the manhole  102 , such hole  70  passing through the concrete wall  104  of the manhole  102 , through the substrate  124 , and through the liner  66 . In this way, the cable  28  running from the sensor  80  may pass through the cross-hole  70  and be connected to the processor/transceiver unit  20 . The cross-hole  70  may be lined or unlined. A corrosion-resistant sleeve  72  may be formed about a portion of the cable  28  and moisture-seal fittings  74  may be installed about the cable  28  at opposite ends of the cross-hole  70  and at the end of the sleeve  72  so as to protect the cable  28  and anchor the cable  28  within the manhole  102 . While electrically wiring the processor/transceiver unit  20  and the sensor  80  together through the cable  28  has structural and operational advantages for the wireless wastewater system monitoring apparatus  10 , as described below, it will also be appreciated that the processor/transceiver unit  20  and the sensor  80  can be configured to communicate wirelessly as well without departing from the spirit and scope of the present invention, particularly insofar as both wired and wireless communication allow for monitoring of wastewater levels while locating the processor/transceiver unit  20  external to the wastewater system  100 . Moreover, while a float-type fluid level sensor  80  is shown and described, numerous other sensors may be employed in the present invention, including beam-, ultrasonic- and sonar-type sensors, for example, that may themselves even be located outside of the wastewater system  100  and, again, which may be wired or wirelessly connected to the processor/transceiver unit  20 . 
   Turning now to  FIG. 2 , there is shown an alternative exemplary embodiment of the wireless wastewater system monitoring apparatus  10 ′ of the present invention in which the enclosure  60 ′ comprises an above-ground container  68  formed substantially of a non-metal, synthetic material so as to again minimize interference with wireless signal transmission from the processor/transceiver unit  20 ′ while still weather-proofing and protecting the unit  20 ′. Such an arrangement may be advantageous where the manhole  102  to be monitored is not located in a roadway  120  or, as in the alternative exemplary embodiment wireless wastewater system monitoring apparatus  10 ′ shown, a wastewater line  106  some distance from any manhole  102  is to be monitored, such as a line  106  running under a sidewalk or other area adjacent to a roadway  120 . The container  68  may be located directly on the ground  124  or, as shown, on a sidewalk or concrete pad  126  outside of the roadway  120  for further stability and protection from the elements. In the exemplary embodiment, then, a substantially vertical cross-hole  70 ′ may be formed so as to communicate between the container  68  and the wastewater line  106 , the hole  70 ′ passing through a wall of the container  68 , the pad  126 , the substrate  124 , and the wall  108  of the wastewater line  106  so that the cable  28  running from the sensor  80 ′ located within the wastewater line  106  may pass through the cross-hole  70 ′ and into the container  68  to connect to the processor/transceiver unit  20 ′. Again, the cross-hole  70 ′ may be lined or unlined and moisture-seal fittings  74  may be installed about the cable  28  at opposite ends of the cross-hole  70 ′ so as to protect and anchor the cable  28 . To provide access to the processor/transceiver unit  20 ′, the container  68  may be formed with a cover, door, or other access opening (not shown) that is sealably secured. It will be appreciated by those skilled in the art that numerous other configurations of water-tight, protective enclosures  60 , such as the container  68  shown, may be employed in the present invention so as to locate the processor/transceiver unit  20 ′ outside of a wastewater system  100  that is to be monitored. 
   As shown in  FIG. 3 , the processor/transceiver unit  20  is configured with at least one microprocessor  22  wired between a power supply  24  and a transceiver  26 . The microprocessor  22 , such as a Phillips 8051 Series microprocessor, and the other processor/transceiver unit electronics are installed on a printed circuit board  34  ( FIG. 5 ). The power supply  24  is preferably a 6V lantern-type battery, though numerous other batteries may be employed in powering the processor/transceiver unit  20  and sensor  80 . The transceiver  26  may be a Motorola Creatalink CL2XT reflex transceiver transmitting at 901.2625 MHz and receiving at 941.0250 MHz and having a reflex text data rate of 6,400 baud. Further, the transceiver  26  may be equipped with an external antenna  36  having a 901–944 MHz, 30 degree vertical beam width and 3 db gain. It will be appreciated by those skilled in the art that each of these electronic components are exemplary and that other suitable components may be substituted without departing from the spirit and scope of the invention. For example, as explained below, two different embodiments of the microprocessor  22  configuration and related circuitry are disclosed, and numerous others are possible as well. Moreover, while the Motorola reflex transceiver  26  is shown and described in use below, numerous other wireless data transmission technologies, such as WiFi and WiMax transceivers, cellular transceivers and software transceivers, both now known or later developed in the art, may be employed in the present invention. Of course, as changes in the electronic components are made, the required power supply  24  may change accordingly, so that, again, the above 6V battery is merely illustrative for use in powering the other components employed in the exemplary embodiment shown and described. With continued reference to  FIG. 3 , all of these electronics are housed within a corrosion-resistant, moisture-tight housing  30  preferably having a moisture-seal cap  32  for selective access to the power supply  24 . The cap  32  is shown as being threadably secured on the housing  30 , though it will be appreciated that any moisture-tight securing mechanism now known or later developed may be used. The cap  32  may also be configured with a connector (not shown) for the sensor cable  28 . Both the housing  30  and the end cap  32  may be formed of any suitable material, but are preferably made of a synthetic material such as nylon. The antenna  36  may extend from the housing  30 , as shown, or be entirely contained within the housing  30 . 
   With the wireless wastewater system monitoring apparatus  10  of the present invention so configured, the processor/transceiver unit  20  is, again, positioned within the protective enclosure  60  and the fluid level sensor  80  is located in the wastewater system  100 . Whether the sensor  80  is placed in a manhole  102  ( FIG. 1 ) or a wastewater line  106  ( FIG. 2 ), it is positioned at a height above the normal fluid level  110  determined by the operator to be an overflow condition warranting an alarm notification. When thus installed in the field, as explained in more detail below, the processor/transceiver unit  20  defaults to a standby mode in which the sensor  80  is continuously powered by the power supply  24  and monitored across the cable  28  under the control of the microprocessor  22 , while the other components of the processor/transceiver unit  20 , including the transceiver  26 , are not powered. When the fluid level  110  rises and an overflow condition is detected by the sensor  80 , the sensor  80  sends an overflow signal via the cable  28  to the microprocessor  22  of the processor/transceiver unit  20 . In response to the overflow signal, the microprocessor  22  then “awakens” the rest of the processor/transceiver unit  20  and transmits a wireless alarm signal via the transceiver  26  so that the operator can take appropriate action. It will be appreciated by those skilled in the art that the present invention thus provides for automated wastewater overflow notification while minimizing power consumption and wireless airtime by the processor/transceiver unit  20  being fully powered and sending a wireless alarm signal essentially only when an overflow condition has been detected. Because, as above, the alarm signal is sent from a location other than the manhole  102  so as to not be attenuated by the manhole cover  112  in particular, further power consumption is avoided by not having to increase signal strength in attempting to overcome these attenuating effects and the signal is transmitted more reliably. As such, the present invention provides for improved signal transmission and all but eliminates unit failures due to battery loss and to the corrosive effects of the wastewater system  100 , ultimately resulting in more effective response to wastewater overflow conditions and a corresponding reduction in sewage spills. 
   Referring now to  FIG. 4 , there is shown a first exemplary embodiment of the circuitry of the processor/transceiver unit  20 . Particularly, the at least one microprocessor  22  includes a first “always on” microprocessor  38  and a second “powered up” microprocessor  40 . The “always on” microprocessor  38  is wired to the sensor  80  and to the power supply  24  and is configured to be constantly powered by the power supply  24  so as to continuously power and monitor the sensor  80 , as in the standby mode described above. The “always on” microprocessor  38  is also wired to the “powered up” microprocessor  40  and is further configured to send an “awake” signal to the “powered up” microprocessor  40  when the overflow signal is received from the sensor  80 . The “powered up” microprocessor  40  is wired to the “always on” microprocessor  38 , also to the power supply  24 , and to the transceiver  26  and is configured to be powered by the power supply  24  upon receipt of the awake signal from the “always on” microprocessor  38  so as to control the transceiver  26  to transmit the alarm signal. As shown, the transceiver  26  may be powered by the power supply  24  through a voltage regulator circuit  42  under the control of the “powered up” microprocessor  40 . The “always on” microprocessor  38  is further configured to send an awake signal to the “powered up” microprocessor  40  at a regular interval, whether an overflow condition is detected or not, in order to perform a status-check of the wireless wastewater system monitoring apparatus  10 , including the operation of the sensor  80  and the remaining power of the power supply  24 . Such an awake or status-check signal effectively launches the “powered up” microprocessor  40  into a status-check mode, resulting in the transmission via the transceiver  26  under the control of the “powered up” microprocessor  40  of a status-result signal indicating whether the sensor  80  has a proper logic state and whether a low-battery condition exists. The interval for such status-checks, such as every two weeks, is programmed in the “always on” microprocessor  38 . Again, it will be appreciated that by having only the “always on” microprocessor  38  and the sensor  80  powered constantly and the other components of the processor/transceiver unit  20 , including the “powered up” microprocessor  40  and the transceiver  26 , not powered unless an overflow condition is detected or a routine self-check is being conducted, the overall power consumption is reduced. In fact, the exemplary wireless wastewater system monitoring apparatus  10  can operate on a single 6 V battery for up to nine to twelve months depending on its activity level. In a preferred embodiment of the present invention, the battery-status signal will be included in any alarm signal sent from the processor/transceiver unit  20 , whether in response to an overflow condition or during a routine status-check. 
   Turning to  FIG. 5 , there is shown an alternate exemplary embodiment of the circuitry of the processor/transceiver unit  20  wherein the at least one microprocessor  22 ′ consists of a single microcontroller  44  having a standby clock mode and a normal clock mode. In the standby clock mode, only the sensor  80  and certain portions of the microcontroller  44  and other circuitry are constantly powered, again minimizing current consumption and maximizing battery life. The microcontroller  44  is configured to shift from the standby clock mode to the normal clock mode and power up the remainder of the processor/transceiver unit  20  upon receipt of the overflow signal from the sensor  80  or during the routine-interval status-check mode for which a time value is stored on the microcontroller  44 . Once in normal clock mode, the microcontroller  44  turns on the voltage regulator circuit  42 ′ wired to the microcontroller  44 , to the power supply  24  and to the transceiver  26  so as to power up the transceiver  26  and transmit the alarm or status-result signal under the control of the microcontroller  44 . In both the single microcontroller  44  embodiment ( FIG. 5 ) and the dual microprocessor  28 ,  30  embodiment ( FIG. 4 ) of the at least one microprocessor  22 ,  22 ′, then, it will be appreciated that full power to the circuit and the ensuing wireless data transmission will only occur when prompted. Furthermore, those skilled in the art will appreciate that electrical connection to the sensor  80  enables the sensor  80  to be a relatively simple mechanical device without a separate processor or power supply. As such, the sensor  80 , which is potentially exposed to the corrosive effects of the wastewater system  100  and increased wear and tear generally, thus has a decreased potential for failure and is relatively more compact and less expensive through its decreased number of components and complexity. 
   In  FIG. 6  there is shown a wireless manhole monitoring system generally involving multiple wireless wastewater system monitoring devices  10  according to the present invention installed within a wastewater system  100  as described above and wirelessly linked to a network operations center  132 . Specifically, one or more sensors  80  are located within respective one or more manholes  102 , with each sensor again being configured to send an overflow signal when an overflow condition is detected. Correspondingly, one or more processor/transceiver units  20  are installed within respective one or more enclosures  60  and connected to respective ones of the sensors  80  through cables  28 . While a single sensor  80  is shown as being connected to each processor/transceiver unit  20 , it will be appreciated that any number of sensors  80  could potentially be connected to a single such unit  20 . For the purpose of the following description of the entire wireless manhole monitoring system, each processor/transceiver unit  20  is assumed to be configured as in the embodiment of  FIGS. 1 and 4 , though it will be further appreciated, again, that numerous other configurations of the processor/transceiver unit  20  and its enclosure  60  are possible without departing from the spirit and scope of the present invention. With the processor/transceiver units  20  so installed, each unit  20  is assigned a unit number and uniquely associated with a particular manhole  102  or other location within the wastewater system  100  so that the units  20  can be mapped on a sewage grid for alarms and notifications. This geo-coded mapping data is stored in a database (not shown) at the network operations center  132 . As described in more detail below, many other parameters concerning the operation of the processor/transceiver units  20  may be set and controlled through the network operations center  132 . 
   In use, when each processor/transceiver unit  20  is in the standby mode, the respective sensor  80  is continuously monitored under the control of the first “always on” microprocessor  38  ( FIG. 4 ) while the other components of the unit  20  are not powered, particularly the transceiver  26  ( FIG. 4 ). When the wastewater level  110  rises to the level of a sensor  80 , a float switch or the like initiates a contact closure and the sensor  80  sends an overflow signal along the cable  28  to the “always on” microprocessor  38 . The “always on” microprocessor  38  then sends an awake signal so as to power the second “powered up” microprocessor  40  ( FIG. 4 ) wired to the first microprocessor  38 . In turn, the second microprocessor  40  then powers up and controls the transceiver  26  so as to transmit an alarm signal to the network operations center  132 . For this purpose, an existing wireless carrier  130  provides for wireless communication to and from the processor/transceiver unit  20  in a manner known and used in the art, and transmission of the alarm signal from the wireless carrier  130  to the network operations center  132  may also be through any means now known or later developed, though a landline connection is shown. Again, other means of data transmission now known or later developed may be employed in relaying the alarm signal from the processor/transceiver unit  20  to the network operations center  132 . In the case of wireless transmission of the alarm signal, it will be appreciated by those skilled in the art that the location of the processor/transceiver unit  20  within a synthetic enclosure  60  outside of the wastewater system  100  allows for more reliable transmission of the signal, as compared to transmission from within a manhole  102  where the structure of the manhole  102 , and particularly the iron manhole cover  112  ( FIG. 1 ), is known to interfere with, or attenuate, the transmission of wireless signals. The transmitted alarm signal contains the unit number of the processor/transceiver unit  20  that detected the overflow condition so that the appropriate notification can be provided, such that reliable transmission of the signal is critical to timely response and, ultimately, preventing an unwanted and costly sewage spill. Thus, when the alarm signal is received at the network operations center  132 , a third “network” microprocessor  138 , wired to a memory device  140  containing a database of geo-coded mapping data, accesses the database and compares the information contained in the alarm signal to the district sewage grid. Under the control of the “network” microprocessor  138 , an alarm notification is then sent to the appropriate district operator  134  for corrective action. The interface between the network operations center  132  and the district operator  134  is preferably through an Internet web site. This web-site based interface provides for a series of notification alert capabilities defined by the district operator  134 , including two-way paging, text messaging to cell phones, fax and e-mail. Other modes of communication now known or later developed may also be employed. The district operator  134 , once notified, can then deploy a repair crew  136  to the proper location in the wastewater system  100  for immediate attention to the overflow condition detected by the wireless wastewater system monitoring apparatus  10 . In addition to selecting the preferred mode of notification through the Internet web site interface, the district operator  134  can also select the scheduled interval on which alarm signals are sent from the wireless wastewater system monitoring apparatus  10 . The alarm signals may be scheduled until the condition is remedied and the particular processor/transceiver unit  20  is reset by the repair crew  136 , such as every 15 minutes, for example. Alternatively, the district operator  134  may choose to have the alarm signal resent on a regular interval only until receipt of the alarm signal is acknowledged. In any event, once the alarm signal is received by the district operator  134 , the repair crew  136  is dispatched to the overflow location to correct the condition. The processor/transceiver units  20  may be reset automatically once the overflow condition is corrected and the sensor  80  returned to its at-rest configuration with the contact closure again open. Or, the units  20  may include a reset switch (not shown) to be tripped by the repair crew  136  when servicing the wastewater system  100 . When the units  20  are reset, a reset signal will be sent from the respective processor/transceiver unit  20  to the district operator  134 , again through the network operations center  132  web site by way of the wireless carrier  130 . Such a reset signal provides the district operator  134  with a record of timely service response. In addition to the basic alarm message and the unit number data, the alarm signal may also contain the voltage status of the battery  24  ( FIGS. 3 and 4 ). In this way, the district operator  134 &#39;s notification to the repair crew  136  can also include information related to the battery condition and any corrective action related to the battery  124  can be taken care of on the same service call. A battery status indicator (not shown) may also be located on each processor/transceiver unit  20  itself for a further alert to the repair crew  136  servicing the unit. 
   Each wireless wastewater system monitoring apparatus  10  of the wireless manhole monitoring system of the present invention may also be configured such that the respective processor/transceiver units  20  provide periodic status reporting to the network operations center  132  and, from there, to the appropriate district operator  134 . Accordingly, the “always on” microprocessor  38  ( FIG. 4 ) of each processor/transceiver unit  20  may be programmed to provide an awake or status-check signal at a regular interval so as to power the second “powered up” microprocessor  40  ( FIG. 4 ), such as once every two weeks, for example. Once powered, the “powered up” microprocessor  40  may be programmed to verify the status of the processor/transceiver unit  20 , including the logic state of the sensor  80 , and the remaining power of the power supply  24  and to transmit a status-result signal to the network operations center  132  by the transceiver  26  ( FIG. 4 ). The routine status-check reporting interval may be pre-programmed or selected by the district operator  134 . Either way, the interval is stored in the memory of the “always on” microprocessor  38  so that the status-check signal may be generated appropriately. As with the alarm signal, the status-result signal may be transmitted on a regular interval until receipt by the district operator  134 , or at least at the network operations center  132 , is acknowledged. Regarding the power supply  24  ( FIGS. 3 and 4 ), it will be appreciated, then, that the remaining power is preferably monitored both at regular intervals during status-checks and anytime there is an alarm condition. Moreover, the processor/transceiver unit  20  can be programmed to monitor the battery  24  constantly and automatically send a low-battery signal anytime a low-battery condition is detected. Those skilled in the art will thus appreciate that the wireless manhole monitoring system of the present invention provides for both alarm and routine status notification from a monitoring apparatus  10  to a network operations center  132  while minimizing the use of power and wireless airtime through the configuration of the processor/transceiver units  20  to be in a default standby mode so as to continuously monitor the wastewater system  100  while only awakening the rest of the unit  20  and transmitting a wireless signal when an overflow condition is detected or at the prescribed status-check interval. Power consumption may be reduced even further by configuring respective ones of the transceivers  26  as ultra-low-power so as to effectively serve as repeaters communicating signals back and forth within an established local area network of processor/transceiver units in which only one processor/transceiver unit  20  would be equipped with a higher power transceiver  26  for then sending the appropriate signal on to the network operations center  132  via the wireless carrier  130  as explained above. Such a local area network within a wide area network is yet another example of how the present invention can provide automated wireless wastewater system monitoring with decreased power consumption and increased efficiency. In an exemplary embodiment of the wireless manhole monitoring system, the “powered up” microprocessor  40  ( FIG. 4 ) of the processor/transceiver unit  20  is programmed to compress the alarm, reset and status-result signals before transmitting them, and the “network” microprocessor  138  is likewise programmed to decompress the signals after being received at the network operations center  132 . It will be appreciated by those skilled in the art that this compression/decompression capability further minimizes the total wireless airtime associated with alarm, reset and status notification by the wireless wastewater system monitoring apparatus  10 , thereby contributing to the efficiency of the system. It will also be appreciated, again, that the same functions of transmitting signals essentially only when an overflow condition has been detected or a status-check is being performed and of compressing the signals before being sent can be achieved in other embodiments of the processor/transceiver unit  20  of the present invention, including the alternative embodiment wherein a single microcontroller  44  ( FIG. 5 ) operates within the unit  20 . Moreover, again, the location of the processor/transceiver units  20  outside of the wastewater system  100 , and any manhole  102  specifically, makes the overall system more effective by further reducing power consumption and eliminating the exposure of the units to the corrosive environment of the wastewater system  100 , thereby effectively extending the useful life of the units  20  in the field, and by improving the wireless transmission of data to and from the processor/transceiver units  20 . Thus, the resulting wireless wastewater monitoring system of the present invention provides improved monitoring performance at reduced cost. 
   While the invention has been described with reference to at least two preferred embodiments, it is to be clearly understood by those skilled in the art that the invention is not limited thereto. Rather, the scope of the invention is to be interpreted only in conjunction with the appended claims and it is made clear, here, that the inventor believes that the claimed subject matter is the invention.