Abstract:
An apparatus for enhancing the water quality in a subterranean pressurized water system is disclosed and provides a discharge passage control via a valve that can be actuated electronically at the location of the valve or remotely. The discharge through the apparatus permits the flow of water in the subterranean pressurized water system and a corresponding discharge of contaminants and increased concentration of disinfectants supplied to the subterranean pressurized water system by the water system manager. The discharge can occur directly to a below ground drain such as a storm drain, sewer or drain field.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation of copending application Ser. No. 09/525,203, filed Mar. 14, 2000. application Ser. No. 09/525,203 is a continuation-in-part of copending application Ser. No. 09/096,626, now U.S. Pat. No. 6,035,704 filed Jun. 12, 1998. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002] Not Applicable 
     
    
     
       FIELD OF THE INVENTION  
         [0003]    The invention relates in general to water quality maintenance devices and more particularly to a water sampling and purging apparatus for automatically maintaining water quality in a low flow area of an underground water distribution system.  
         BACKGROUND OF THE INVENTION  
         [0004]    As discussed in the above referenced parent application, traditional underground water distribution systems for residential and commercial areas often incorporate low flow or dead end portions by design. For instance, fire protection and land development codes often require oversized water mains for anticipated fire control and peak water demands. Such design features, although in the best interest of the community, have the effect of dramatically reducing water flow velocity and increasing water retention time within the water distribution system. The problem is further exacerbated by water distribution systems that experience large seasonal fluctuations in demand. These systems often experience additional reduction in water flow during non-seasonal periods of the year.  
           [0005]    Low water flow conditions and corresponding increases in water retention time within portions of the water distribution system have the potential to degrade the chemical and microbiological quality of water transported through the distribution system. Degradation in water quality results from prolonged exposure to water system materials, internal sedimentation, and/or contaminant deposits within the piping system. Disinfectants are commonly used in an effort to control bacterial growth. However, as disinfectant residuals dissipate, bacterial regrowth occurs.  
           [0006]    The Federal Safe Drinking Water Act requires that potable, or drinkable, water systems maintain minimum disinfection residual levels, to prevent the regrowth of bacteria. In fact, mandatory testing programs have been enacted to track compliance and identify potential health hazards. Water systems failing to adhere to regulatory or operational water quality standards are subject to regulatory enforcement action, public disclosure of health hazards, and increased public and regulatory scrutiny.  
           [0007]    Corrosion rates in low flow and stagnant areas can escalate as chemical reactions and microbiological activity increase. Corrosive water tends to dissolve certain materials commonly used in the construction of water distribution systems. The two primary metals of concern are iron and lead. Iron is commonly found in piping system materials. Lead is commonly found in older water systems that have incorporated lead joints, lead composite pipes and/or brass fittings. Elevated iron concentrations can result in violations of drinking water standards. In both potable and non-potable water distribution systems, excessive concentrations of iron can result in staining of structure surfaces, fixtures and clothing.  
           [0008]    Bacterial hazards also abound in low flow or dead end portions of water distribution systems. Increased bacterial concentrations result from reductions in disinfection residuals which retard or prevent the regrowth of such bacteria. Maintenance of adequate water system disinfection residuals is necessary to afford protection from accidental or intentional introduction of microbiological contaminants into the distribution system. Microbiological films, referred to in the art as bio-films, can form on water distribution system components where adequate disinfectant residual levels are not maintained. Removal of such films is expensive and time consuming.  
           [0009]    Historically, water distribution system compliance with water quality regulatory standards has been evaluated through the collection of water samples. Presently, samples are collected from private plumbing systems and stationary water sampling stations installed along the water system distribution system. These designated sampling locations often produce test results that are either inaccurate or not representative of water quality throughout the water distribution system.  
           [0010]    Historically, the primary means of addressing water quality degradation in low flow or dead end areas has been to dispatch workers, on a complaint-by-complaint basis, to manually purge the water from a problem area of the system. This method does not provide an adequate solution, since its success is contingent on financial and human resource availability.  
           [0011]    Another approach that has been employed to supplement manual flushing operations has been the use of increased concentrations of disinfectant residuals, in an attempt to counteract the effects of disinfectant residual dissipation, which is a time dependent function of chemical and biological reactions. Using this approach, the disinfectant residual level of the entire system is increased or, alternatively, disinfectant booster stations are positioned at strategic areas along the water distribution system. However, due to suspicions that chlorine and other water-disinfecting chemicals may be carcinogenic, or responsible for creating carcinogenic substances during the disinfection process, there is a general consensus that dosage rates must be minimized. For instance, the Federal Safe Drinking Water Act is expected to establish a maximum limit of 4 mg/l for chlorine.  
           [0012]    The prior art does not provide an adequate solution for addressing the aforementioned water quality degradation problems common at low flow and dead end areas of water distribution systems. The need for an adequate solution has been heightened as a result of an increase in the occurrence of known and suspected carcinogens in water distribution systems. Further, manual purging of low quality water causes excessive amounts of water to be discharged from the system thus making operation impractical in areas of poor drainage and high pedestrian/vehicular traffic. Moreover, prior art systems are generally shut down in subfreezing temperatures to protect system components from the expansion of freezing water.  
           [0013]    Accordingly, what is needed is an apparatus capable of analyzing water quality and purging low quality water from low flow or dead end areas of water distribution systems. Various configurations can be provided to make the system adaptable to address particular drainage and traffic conditions. In some cases, it would be desirable for the aforementioned apparatus to have an internal control system capable of automatically monitoring water quality and, subsequently, purging low-quality water from the low flow area based upon user defined water quality limits. In some cases, it would be further desirable for the analytical and purging functions of the apparatus to be controllable by a remotely operated device. Additionally, it would also be desirable, in some cases, for the apparatus to provide a system for permitting operation of the apparatus in subfreezing temperatures and a device for preventing contaminants from entering the water distribution system.  
         SUMMARY OF THE INVENTION  
         [0014]    The present invention provides an efficient and cost-effective means for maintaining water quality in low flow or dead end areas of an underground water distribution system. The invention generally embodies an apparatus for the automated analysis of water samples and purging of low quality water from such areas on an as-need basis. The apparatus greatly reduces present human resource requirements associated with performing these functions.  
           [0015]    The apparatus is adapted for mounting above and below grade level, housing both above-and below-ground components. The major below-ground components of the apparatus can include the following: a water purging portion; a water inlet for introducing water from the water distribution system into the apparatus; a water carrier system for transporting water through the apparatus; an isolation valve for controlling the introduction of water into the apparatus; a flow control valve for controlling the flow of water through the apparatus; a freeze protection bypass system for permitting apparatus operation in subfreezing temperatures; a backflow prevention device for preventing contaminants from entering the water distribution system; a water quality monitoring system; and an electronic control system for activating, monitoring, and deactivating sampling and purging functions of the apparatus. Various optional components are also contemplated. For instance, radio and/or telephonic telemetry equipment may be housed in the below-ground portion of the apparatus for remote activation and deactivation of the apparatus.  
           [0016]    The major above-ground components of the apparatus can include the following: a freeze protection bypass system; a backflow prevention device; a programming/data transmission access port; electrical/optical sensing devices; an external water quality sampling adapter; and a power source. The programming access port receives operational instructions from a remotely-held programming device. Various optional components are also contemplated. For instance, a turbine generator may be housed in the above-ground portion of the apparatus for recharging the power source.  
           [0017]    Generally, instructions are communicated from a hand held remote control device through the programming access port to a programmable solenoid controller which is a subcomponent of the electronic control system. Preferably, the solenoid controller has date and time function capabilities such that a remote operator can program the apparatus to perform water purging functions at programmed times. The programmable solenoid also communicates with chemical, electronic and/or optical sensing devices, providing a means for purging based upon water quality parameters. Preferably, the power source comprises a rechargeable battery. The system can be housed in a water tight housing to prevent damage to internal components. The housing is specially designed to allow easy access to internal components. Preferably, bulky system components are stored below grade level in a specially designed water tight compartment, leaving only the relatively small aesthetically engineered portion of the housing above grade level. A protective cover can be used to house those components that are placed above ground.  
           [0018]    One embodiment of a system for controlling and enhancing water quality in a subterranean pressurized water distribution system has been described in Applicant&#39;s application, U.S. application Ser. No. 09-096,626, now U.S. Pat. No. 6,035,704, which is incorporated herein by reference. This embodiment provides for a downwardly directed discharge above ground. This discharge approach provides several advantages including the avoidance of dangers to passing pedestrians and traffic from high pressure discharge.  
           [0019]    [0019]FIG. 1 discloses another embodiment for controlling and enhancing water quality in a subterranean pressurized water distribution system. The apparatus pictured in FIG. 1, a direct discharge subterranean discharge system, provides a discharge path that directs low quality water from a subterranean pressurized water distribution system to a below grade location such as a storm drain, sewer line or drain field. The apparatus is adapted for above and below ground, or grade level  180 , mounting. As used herein, the term “upper portion” denotes structure located above grade level  180 , and the term “lower portion” denotes structure located below grade level  180 .  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    [0020]FIG. 1 illustrates an embodiment of a direct discharge subterranean discharge system in accordance with the principles of the present invention.  
         [0021]    [0021]FIG. 2 is a block diagram illustrating the interaction of the major system components of the apparatus of the present invention.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0022]    While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from consideration of the following description in conjunction with the drawing figures in which like reference numerals are carried forward.  
         [0023]    In the preferred embodiment, the major components of the apparatus include the following: a housing; a water transport apparatus; a freeze protection bypass apparatus; a water flow control valve; a backflow prevention device; a programmable solenoid controller; a programming/data retrieval port; an electronic data control system; chemical, electronic and/or optical sensing devices; and a power source. Additionally, the apparatus may include a telephone and/or radio telemetry interface control system. The major system components each comprise subsystem components which cooperate to provide the advantages of the present invention.  
         [0024]    Initially, water from a water distribution system (not shown) is received in water carrier piping  112  through water inlet  110 . The dimensions and configuration of water inlet  110  are adapted for connection to the particular water distribution system piping. Water carrier piping  112  is made up of individual pipe segments. The carrier piping system is supported by various restraint mechanisms.  
         [0025]    Water inlet  110  is connected to isolation valve  118 . Isolation valve  118  controls the introduction of water into the apparatus. Under certain circumstances, it may be desirable to cut off water flow to the apparatus. For instance, isolation may be desirable when the apparatus is undergoing repair. Furthermore, if the apparatus is not equipped with a freeze protection bypass system, the isolation valve may be closed in subfreezing temperatures to isolate water from internal components thereby preventing component damage from the expansion of freezing water. Carrier piping  112  connects isolation valve  118  and carrier pipe elbow  117 A. Carrier pipe elbow  117 A transitions the carrier piping from a horizontal to vertical direction. Carrier piping  112  extends through a gasketed opening in lower housing support platform  155  and through another gasketed opening at the top of lower housing  154  and connects to carrier pipe elbow  117 B. Carrier piping  112  is transitioned back to a horizontal direction by carrier pipe elbow  117 B and connects to the inlet of water flow control valve  119 .  
         [0026]    Flow control valve  119  varies water flow through the apparatus thereby controlling the corresponding rate at which water is purged. In contrast to the manual methods of the prior art, the flow control valve of the present invention enables the discharge, or purging, of water at a controlled rate of flow over an extended period of time. As a result, the potential for land damage from erosion and flooding at the eventual draining site is greatly reduced. The outlet of flow control valve  119  is connected through carrier pipe elbows  117 C and  117 D and carrier piping  112  to the inlet of backflow prevention device  190 . Backflow prevention device  190  is provided to prevent contaminants from entering the subterranean water distribution system through the apparatus. An auxiliary water sampling feature located between the outlet of flow control valve  119  and the inlet of backflow prevention device  190  is provided for performing manual on-site testing. The manual water sampling feature comprises water sampling adapter  122  which is configured to be adapted to carrier piping  112  through adapter  115 . Preferably, water sampling adapter  122  is a quick connect/disconnect connector, as is well known in the art.  
         [0027]    The carrier piping that is connected to the discharge side of backflow prevention device  190  through carrier pipe elbows  117 E,  117 F,  117 G and  117 H provides a discharge routing conduit for discharging low quality water to a subterranean drain system (not shown). As a result, this configuration allows low quality water to be purged subterraneously, thus permitting the apparatus to be installed in areas of inadequate surface drainage and/or high pedestrian/vehicular traffic. Further, this disposal option alleviates property and safety concerns associated with atmospheric flushing in such sensitive areas.  
         [0028]    The apparatus can be fitted with a temperature activated freeze protection bypass system (not shown) that bypasses flow control valve  119  thereby enabling the apparatus to be operated in subfreezing temperatures. Since the present embodiment does not discharge water to the atmosphere, as opposed to the configuration disclosed in the parent application, the operational and safety hazards resulting from the formation of ice are eliminated. Thus, warmer water from the subterranean water distribution system can be flushed through the above grade components for their protection without activating flow control valve  119  when the water temperature in these components drops below a preset temperature.  
         [0029]    The subterranean discharge configuration can incorporate all the remaining primary components of the above ground discharge embodiment of the parent application but does not require the water flow dissipater which is not required because low quality water is discharged below grade. Specifically, programming/data retrieval port  130 , such as a standard handset telephone jack, is integrated into the upper portion of the apparatus housing. Programming/data retrieval port  130  is adapted for receiving programming instructions from a remote hand-held programming device (not shown). For instance, the hand-held programming device could comprise a lap top computer. The hand-held electronic device communicates programming instructions (e.g., activation time) to programmable solenoid controller  131 . Port  130  provides for bidirectional communication between the programming device and the programmable solenoid controller  131 . As a result, stored data can be downloaded from the apparatus to the hand-held electronic device for analysis. Solenoid controller  131  is provided for activating and deactivating flow control valve  119 . Therefore, instructions communicated from the remote programming interface function to control the activation and deactivation of flow control valve thereby controlling the purging functions of the apparatus. For instance, programmable solenoid  131  can be programmed to activate flow control valve  119  at a specific time and date for a specified duration of time. Alternatively, chemical, electronic and/or optical sensing devices  120  provide a means for purging based on specific water parameters.  
         [0030]    Chemical, electronic and/or optical sensing devices  120  are provided for measuring water quality parameters. In particular, the sensing devices are provided for measuring chemical and bacterial content of the water. The use of sensing devices for measuring water quality parameters is well known in the art. For instance, a water analyzing probe having a variety of sensors or electrodes for measuring various parameters of ground water is disclosed in U.S. Pat. No. 5,261,348 to Niehaus, et al. Sensing devices  120  could include pH electrodes, temperature sensors, or chlorine sensors, to name just a few. The sensing devices can be positioned at various locations within the apparatus. For instance, sensing devices  120  are positioned to test the water as it flows through carrier piping  1   12 . Alternatively, sensors can be configured to provide continuous water sampling by connection, via sampling tubes, to water carrier piping  112  both before and after control valve  119 . In this configuration, a minimal, continuous flow of water will exit through the apparatus. Through power cable interconnects, a signal from sensor device  120  can be communicated to data control system  121  and programming and data retrieval port  130 . Subsequently, the monitoring signal from sensor device  120  can be used by control system  121  to activate control valve  119  through the programmable solenoid controller  131 .  
         [0031]    In the preferred embodiment of the present invention, the apparatus has electronic data control circuitry  121 , including a microprocessor (not shown) for retrieving, storing, and transmitting data. Control circuitry  121  can be programmed through programming port  130  with a variety of instructions, including acceptable water parameter criteria. Programmed criteria stored by control circuitry  121  can be compared to measurement data communicated from sensing devices  120  to control circuitry  121 . Control circuitry  121  has decision-making capabilities and, as a result, can signal solenoid controller  131  to activate or deactivate flow control valve  119 , depending on the water quality test data.  
         [0032]    In an alternative embodiment of the present invention, a telephone and/or radio telemetry interface control system  172  is housed in lower housing  154 . These components provide a means for direct remote activation, monitoring and deactivation of the invention. The optional telemetry components can also be interfaced, either directly or indirectly, with programmable solenoid  131  to permit programming of the apparatus from remote locations.  
         [0033]    The apparatus is powered by power source. Preferably, the power source comprises a battery, which may or may not be rechargeable. In an alternative embodiment of the present invention, at least one supplemental power source is provided. For instance, where power source is a rechargeable battery, at least one solar cell can be provided for recharging the battery. The optional solar cell provides low-power, continuous recharging capabilities to the battery, enabling increased operating intervals between replacement or supplemental external recharging.  
         [0034]    Furthermore, an internal water-powered turbine electric power generator can be provided. Electric turbine generator uses the stored kinetic energy in the pressurized water being discharged to rotate an in-line turbine, which in turn operates an electrical generator (not shown). The electrical generator is capable of meeting the electrical requirements of the invention&#39;s various electrical and electronic configurations. The turbine generator is also capable of recharging optional back-up batteries or other supplemental battery power sources.  
         [0035]    The apparatus housing has other various features which will now be described. Preferably, lower housing  154  protects the below grade components from the elements. Additionally, lower housing support platform  155  has a larger area than the remainder of the apparatus which allows for distribution of the weight of the apparatus over a greater surface area thereby reducing the unit loading on the load bearing surface and minimizing the potential for settling. Lower housing  154  can be provided with an emergency relief valve. In the event of a leak or other material failure in the pressurized portion of the apparatus, i.e., in lower housing  154 , an emergency relief valve provides a means for pressure relief thereby minimizing the potential for damage to electrical and electronic components housed in lower housing  154 . Protective cover  300  houses the above grade components.  
         [0036]    Referring now to FIG. 2, although the interaction of the various components of the apparatus of the instant invention has now been described in substantial detail, a block diagram summarizing this interaction is provided. At a minimum, hand-held programming device/interface  330 , programming &amp; data retrieval port  320 , programmable solenoid  310  and flow control valve  300  are provided. Operating instructions are communicated from device  330 , through port  320 , to programmable solenoid  310 . Based upon the instructions received by solenoid  310 , flow control valve  300  may be activated or deactivated for a period of time.  
         [0037]    The preferred embodiment of the present invention further comprises central data control system  340  and sensing devices  350 . In this embodiment, water quality criteria can be communicated from control system  340  to sensing devices  350 , while specific water quality test data can be communicated from sensing devices  350  to control system  340 . Based upon the water quality criteria and test data, control system  340  can signal programmable solenoid  310 , either directly or through port  320 , to activate or deactivate flow control valve  300 . Hand-held programming/data retrieval unit  395 , which preferably comprises a portable computer, communicates bidirectionally with data control system  340 .  
         [0038]    Optionally, telephone or radio telemetry interfaces  360 ,  370  can be integrated into the system of the instant invention, as a means for providing bidirectional communication with remotely operated devices  380 ,  390 . For instance, remote devices  380  and  390  may be used to directly activate or deactivate the purging functions of the apparatus from afar, by communicating, through interfaces  360  and  370 , respectively, with central control system  340 .  
         [0039]    While the preferred embodiments of the invention have been illustrated and described, it will be clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention as described in the claims.