433Maintaining a free chlorine residual and regular flushing of water mains may control the growth of
iron bacteria in a water distribution system.
IRON BACTERIA: Perhaps the most troublesome consequence of iron and manganese in the
water is they promote the growth of a group of microorganism known as Iron Bacteria.
IRON FOULING: You should look for an orange color on the resin and backwash water when
checking an ion exchange unit for iron fouling
IRON: Fe The elements iron and manganese are undesirable in water because they cause
stains and promote the growth of iron bacteria.
IUPAC: International Union of Pure and Applied Chemistry
J
JODIUM: Latin name of the halogen element iodine.
JOULE: The SI unit of energy, defined as a newton-meter.
K
KILL = C X T: Where other factors are constant, the disinfecting action may be represented by:
Kill=C x T. C= Chlorine T= Contact time.
KINETIC ENERGY: The energy of an object due to its motion. The ability of an object to do work
by virtue of its motion. The energy terms that are used to describe the operation of a pump are
pressure and head.
KINETICS: A sub-field of chemistry specializing in reaction rates.
L
L.O.T.O.: Lock Out, Tag Out. If a piece of equipment is locked out, the key to the lock-out device
the key should be held by the person who is working on the equipment. The tag is an
identification device and the lock is a physical restraint.
LACRIMATION: The secretion of tears, esp. in abnormal abundance Also, lachrymation,
lachrimation.
LANGELIER INDEX: A measurement of Corrosivity. The water is becoming corrosive in the
distribution system causing rusty water if the Langelier index indicates that the pH has decreased
from the equilibrium point. Mathematically derived factor obtained from the values of calcium
hardness, total alkalinity, and pH at a given temperature. A Langelier index of zero indicates
perfect water balance (i.e., neither corroding nor scaling). The Langelier Saturation Index
(sometimes Langelier Stability Index) is a calculated number used to predict the calcium
carbonate stability of water. It indicates whether the water will precipitate, dissolve, or be in
equilibrium with calcium carbonate. Langelier developed a method for predicting the pH at which
water is saturated in calcium carbonate (called pHs). The LSI is expressed as the difference
between the actual system pH and the saturation pH.
LANTHANIDES: Elements 57 through 71.
LATTICE: Unique arrangement of atoms or molecules in a crystalline liquid or solid.
LAW OF MOTION: An object in motion stay in motion an object in rest stays in rest unless an
unbalanced force acts on it.
LEACHING: A chemical reaction between water and metals that allows for removal of soluble
materials.
LEAD AND COPPER: Initial tap water monitoring for lead and copper must be conducted during
2 consecutive 6-month periods.
LIGHT: Portion of the electromagnetic spectrum which is visible to the naked eye. Also called
"visible light."
LIME SODA SOFTENING: In a lime soda softening process, to the pH of the water is raised to
11.0. In a lime softening process, excess lime is frequently added to remove Calcium and
Magnesium Bicarbonate. The minimum hardness which can be achieved by the lime-soda ash
process is 30 to 40 mg/L as calcium carbonate. The hardness due to noncarbonate hardness is
most likely to determine the choice between lime softening and ion exchange to remove
hardness.
LIME SOFTENING: Lime softening is primarily used to “soften” water—that is to remove calcium
and magnesium mineral salts. But it also removes harmful toxins like radon and arsenic. Though