Method and apparatus to improve well water quality

An apparatus for drawing water essentially free of sand from a well hole sunk in a sandy, water-bearing strata comprising:

• a tubular suction control tail positioned submerged beneath the level of water within the well hole having a porous, permeable sidewall, an opening at the lower end of the tail admitting water and any sand particles suspended in the water into the tail and a hollow interior hydraulically coupled with water in the well hole through the sidewall and lower end opening;
• pump means having an inlet hydraulically coupled with the hollow interior of the tail through an opening at the upper end of the tail for drawing water from the well hole through the permeable sidewall, lower end opening and the hollow interior of the tail;
• the sidewall comprising an inner, rigid tubular member with an outer surface, an inner surface and a multiplicity of openings therethrough and an outer layer of granular particles bonded together in a porous, permeable layer against the outer surface of the rigid member over the openings;
• and
• the sidewall having a porous, permeable area sufficiently large and of sufficient length and sufficiently low permeability whereby, under the normal operating rate of the pump means, the rate of flow of water into the tail at each point along the permeable sidewall and at the lower open end is less than a rate of flow necessary to overcome inertia of sand in the adjoining strata.

An improved method of pumping water essentially free of sand from a well hole sunk in a sandy, water-bearing strata comprising the steps of:

• hydraulically coupling one end of a hollow, tubular suction control tail with an inlet of a pump, the tail having a sidewall extending away from the pump inlet into the well hole and being permeable at more than one location along its length, the sidewall having a lower absolute permeability proximal to the pump inlet and a higher absolute permeability distal to the pump inlet;
• centrally positioning the tail and inlet in the well hole beneath the water level;
• and
• drawing water into the tail and inlet by means of the pump through the sidewall of the tail at velocities less than a velocity necessary to remove sand from the strata surrounding the well hole whereby the water is withdrawn by the pump essentially sand free.