Field Water Purification

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Field water purification system Abstract A lightweight water treatment system which can be easily distributed and employed by disaster survivors for treating locally available freshwater sources. The water treatment system includes an internal storage volume for maintaining a predetermined volume of water, a water fill port in communication with the internal storage volume provided at a first end of the elongated container for receiving the predetermined volume of water, a sealing member disposed at about the first end of the elongated container for maintaining the volume of water within the internal storage volume, a second end of the elongated container for receiving sediment settling out of the predetermined volume of water and a discharge port disposed superjacent to the second conically-shaped end for controllably releasing at least a portion of the water maintained within the internal storage volume of the elongated container. Cross-reference and priority claim to related applications This application claims benefit and priority as a Continuation-in-part of co-pending U.S. patent application Ser. No. 12/111,130, filed Apr. 28, 2008 to a common inventor and assignee; the entire contents of which is hereby incorporated by reference as if fully set forth herein, under 35 U.S.C. §120. ​Relevant Inventive Field The present disclosure generally relates to water treatment and more specifically to potable water treatment employed in a field environment. Background Potable water is essential for life. However, in many parts of the world potable water is not readily available particularly under natural disasters conditions such as fires, drought, flooding or earthquakes which may have caused normal sources of potable water to become contaminated. As such, disaster relief response requires that potable water be made available to the disaster survivors as soon as possible. This frequently requires that potable water be brought in from other unaffected areas which is slow, costly and difficult to distribute to the those in the most need of the potable water. In many cases, indigenous water may be available and could suffice if adequate treatment could be performed to remove pathogenic organisms and other contaminants such as dissolved and suspended organic matter, toxic metals and sediment. As with supplied potable water, skid mounted or package water treatment systems require that the equipment be brought to the disaster location and operated from a generally centralized location from which potable water is distributed. While this response may be a viable solution over a protracted period of time, the disaster survivors located in remote areas may not be able to receive potable for several days, thus a need exists that provides a simple and effective way to provide potable water to disaster survivors before more elaborate water treatment systems are made available. The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section. Summary The various exemplary embodiments described herein address the limitations of the relevant art and provides a lightweight water treatment system which can be employed by disaster survivors using locally available freshwater sources. In accordance with one exemplary embodiment, a water treatment system for purifying water in a field environment is provided. In one exemplary embodiment, the water treatment system includes a water treatment agent for treating a predetermined volume of water obtained from a local freshwater source. The water treatment agent includes a flocculant to remove suspended solids, a biocide to disinfect the obtained water from pathogenic organisms and/or activated charcoal for adsorbing hydrocarbons present in the obtained freshwater. The chemical constituency of the water treatment agent may be varied to address specific biological, chemical or radiological contaminates which may be present in the water to be treated. For purposes of this specification, the term “flocculent” includes a coagulant. The obtained freshwater is both collected and maintained in an elongated container. In one exemplary embodiment, an effective amount of the water treatment agent is provided to treat a predetermined volume of water maintained within the elongated container. The elongated container further includes an internal storage volume for maintaining the predetermined volume of water for treatment. In one exemplary embodiment, the internal storage volume includes a headspace of air occupying at least 5% of the internal storage volume when the elongated container is filled with a predetermined amount of water. The headspace of air forms an agitation bubble for mixing the water treatment agent in the predetermined volume of water maintained within the internal storage volume. A water fill port in communication with the internal storage volume is provided at a first end of the elongated container for receiving the predetermined volume of water. A sealing member is provided generally in juxtaposition to the first end of the elongated container for maintaining the volume of water within the internal storage volume for treatment. The sealing member may use a clamp, a pair of opposing and interlocking transverse ridges, tape, a twist-tie, tie-wrap, hook-and-loop fasteners, a rollable section of the elongated container, a draw string and/or any combination of these mechanisms. A second end of the elongated container is used to receive sediment settling out of the predetermined volume of water. In one exemplary embodiment, the second end of the elongated container may include a sediment release valve for releasing sediment from the elongated container. In one exemplary embodiment, the second end of the elongated container includes a conical cross section in communication with the internal storage volume for collecting the sediment. A discharge port in communication with the internal storage volume is provided to allow the user to controllably release the water maintained within the internal storage volume of the elongated container. In one exemplary embodiment, the diameter of the discharge port may be dimensioned to provide a predetermined flow rate based on gravity flow through the discharge port. A filtration member is provided for removing impurities from water released through the discharge port. The filtration member includes an inlet nozzle configured to provide a snug fit within the discharge port, a filter case which contains a filter element, and an outlet nozzle configured to provide a snug fit with an end of a treated water supply conduit. In one exemplary embodiment, the treated water supply conduit is a flexible hose or straw which connects to the filtration member either in juxtaposition to the discharge port or at the conduit's distal (outlet) end. The elongated container includes a compartment or receptacle for maintaining the filtration member in juxtaposition with the discharge port. The elongated container is provided with one or more internal baffles for agitating the predetermined volume of water during treatment. The one or more baffles may be aligned longitudinally, laterally or diagonally within the internal storage volume of the elongated container. One or more straps, handles or grips are attached to the elongated container for transporting the elongated container and/or agitating the water during water treatment. The straps may be configured to allow the user to transport the elongated container as a sling, a backpack or as a neck pack. The elongated container consists essentially of a plastic bag having a thickness in a range of 6-40 mils, a storage volume in a range of 5-30 liters of water and a length-to-width ratio in a range of about 3:1-8:1. A filtration member for filtering the water released from the discharge port is provided. The filtration member may utilize a filter cloth or a wire mesh having a pore size less than 0.5 millimeters to ensure certain pathogenic organisms which may be resistant to the biocide are removed from the treated freshwater before consumption. The collected freshwater is treated using the water treatment agent. The freshwater contained in the elongated container is then agitated by longitudinally rocking the elongated container back and forth a sufficient amount to effectively mix the water treatment agent with volume of water maintained within the internal storage volume and/or axially rotating the elongated container a sufficient amount to effectively mix the water treatment agent with the freshwater maintained within the internal storage volume. Once a sufficient amount of agitation has been provided, the elongated container left undisturbed to allow settable solids to settle from the freshwater and allow the biocide sufficient time to disinfect the freshwater. In one exemplary embodiment, a clarity indicator for determining an effectiveness of the water treatment agent is provided. The clarity indicator allows the user to determine the effectiveness of the water treatment based on light transmission through the elongated container.