Abstract: In one embodiment, a sand boil filter apparatus has a filter cone including an inner cone mesh and an outer cone mesh, the inner cone mesh having a finer mesh than the outer cone mesh. A filter tube extends through the hollow interior of the filter cone. The filter tube includes a lower portion disposed below the open apex. The filter tube includes an upper portion disposed above the open base. The upper portion has a plurality of sets of exit openings which are spaced along a length of the upper portion to provide different possible exit heights for the plurality of sets of exit openings, each set including one or more exit openings disposed at an exit height of the filter tube. An exit height adjustment tool blocks all of the exit openings disposed below a set of unblocked exit openings selected to provide a corresponding exit height.

Abstract: In one embodiment, a sand boil filter apparatus has a filter cone including an inner cone mesh and an outer cone mesh, the inner cone mesh having a finer mesh than the outer cone mesh. A filter tube extends through the hollow interior of the filter cone. The filter tube includes a lower portion disposed below the open apex. The filter tube includes an upper portion disposed above the open base. The upper portion has a plurality of sets of exit openings which are spaced along a length of the upper portion to provide different possible exit heights for the plurality of sets of exit openings, each set including one or more exit openings disposed at an exit height of the filter tube. An exit height adjustment tool blocks all of the exit openings disposed below a set of unblocked exit openings selected to provide a corresponding exit height.

Abstract: In certain embodiments, a sand-boil filter includes a hollow, conical, water-porous structure made of a mesh material having spaced mesh holes. The filter is inserted narrow-end down into a sand boil to allow water to flow from the ground through the mesh material and out the top of the sand boil, while blocking solid matter larger than the mesh holes from passing through the mesh material. In some implementations, the filter is filled with gravel that holds the filter in place while allowing water to flow out of the sand boil. Such filters prevent sand boils from growing while relieving the underground hydrostatic pressure that created the sand boil in the first place and inhibiting subterranean erosion that can cause failure of a nearby levee. The conical shape provides relatively large surface area that inhibits clogging and allows each filter to be used for a range of different sand-boil sizes.

Abstract: In certain embodiments, a sand-boil filter includes a hollow, conical, water-porous structure made of a mesh material having spaced mesh holes. The filter is inserted narrow-end down into a sand boil to allow water to flow from the ground through the mesh material and out the top of the sand boil, while blocking solid matter larger than the mesh holes from passing through the mesh material. In some implementations, the filter is filled with gravel that holds the filter in place while allowing water to flow out of the sand boil. Such filters prevent sand boils from growing while relieving the underground hydrostatic pressure that created the sand boil in the first place and inhibiting subterranean erosion that can cause failure of a nearby levee. The conical shape provides relatively large surface area that inhibits clogging and allows each filter to be used for a range of different sand-boil sizes.