Infiltration Gallery. A sizable gallery with openings in its sides and bottom, extending
generally horizontally into a waterbearing formation, for the purpose of collecting the
water contained therein.
Influent. Water flowing into a reservoir, basin, treatment plant, or a part thereof
Inorganic Matter. Chemical substances of mineral origin; not of basically carbon
Intermittent Stream. A stream or portion of a stream that flows only in direct response
to precipitation. It receives little or no water from springs and no long-continued supply
from melting snow or other sources.
Interstice. A pore or open space in rock or granular material, not occupied by solid
matter. Also called void or void space.
Ion. An electrically charged atom (N+, A1+3, C1-, S-2 or group of atoms known as
Ion Exchange. A process whereby water is passed through a granular material and
ions of the granular material are replaced by ions contained in the water. For example,
in the zeolite softening process the sodium ions (Na+) of the granular zeolite are
replaced by the calcium ions (Ca++) in the water to leave the water free of calcium, the
cause of hardness, but containing an equivalent amount of sodium.
Ionization. The process of the formation of ions by the splitting of molecules of
electrolytes in solution.
Jar Test. A laboratory test used to determine the optimum amounts of coagulant to be
added or most efficient coagulation.
Jetting. (1) A method of well sinking wherein the casing is sunk by driving while the
material inside is washed out by a water jet, and carried to the top of the casing. (2) A
method of sinking piles by means of a water jet. (3) A method of inserting well points
by means of water jet.
Kilopascals. A unit of pressure equal to 0.01 atmosphere or 0.14501 psi.
Lagooning. The placement of solid or liquid material in a basin, reservoir, or artificial
impoundment for purposes of storage, treatment, or disposal.
should have to be in equilibrium with its content of calcium carbonate.