Deep lysimeter

#The invention relates to suction samplers and lysimeters. The invention also relates to methods of obtaining liquid samples from wells.

#As understanding of the effects of soil and water contamination advances, it is increasingly desirable to facilitate groundwater sampling and analysis. Various methods have been employed to extract a soil water sample, including extraction of a soil core, introduction of vacuum-based or absorptive devices or materials, use of suction lysimeters, solution samples, and other methods. There are several types of lysimeters including weighing lysimeters and suction lysimeters. The term “lysimeter,” as used below, refers to a suction lysimeter.

#A suction lysimeter is a hydrological instrument used to sample liquids or monitor in soil or like substrates. The lysimeter accomplishes this function by application of vacuum or pressure gradient principles such that the liquid of interest is drawn toward the lysimeter permitting collection of a liquid sample. A filter arrangement is frequently employed in conjunction with a lysimeter such that undesired particulate or other solids are not accumulated with the desired sample liquid.

#Preferred embodiments of the invention are described below with reference to the accompanying drawings, which are briefly described below.

#FIG. 1 is a front elevational schematic showing a suction bailer in accordance with one embodiment of the invention in use in a well.

#FIG. 2 is a perspective view of a suction bailer in accordance with an alternative embodiment of the invention.

#The invention provides a method of retrieving a liquid sample comprising providing a portable lysimeter including a semi-permeable member and a chamber in fluid communication with the semi-permeable member; providing a hole into the earth at a site from which a liquid sample is desired; applying a vacuum pressure to the chamber; lowering the portable lysimeter into the bore; obtaining a liquid sample in the chamber; and retrieving the lysimeter from the bore; wherein it is not necessary to backfill the hole.

#Another aspect of the invention provides a portable lysimeter, comprising a tube having an inner surface and an outer surface, a first end, and a second end, and defining a chamber; a semi-permeable member bonded to the first end of the tube; a plug sealing the second end of the tube, the plug having an aperture through it in fluid communication with the chamber; a vacuum line in fluid communication with the aperture and in fluid communication with the chamber via the aperture; a valve in the vacuum line; and line connection structure attached to the lysimeter wherein the lysimeter may be retrieved from the sampling location.

#Another aspect of the invention provides a portable lysimeter comprising collection vessel including a cavity defining a collection chamber, a first end including a porous member, and a second, threaded, end; and a connector portion including a first threaded coupling selectively threaded to the second, threaded, end and having a second coupling including a check valve connector including an integral check valve, the check valve connector having a quick-disconnect connector portion for use with a quick-disconnect connector coupled to a pump.