421to the nitrogen atom mass is 4.43. Thus a concentration of 10 mg/L nitrate expressed as nitrogen
would be equivalent to a concentration of 44.3 mg/L nitrate expressed as nitrate ion. When
dealing with nitrate numbers it is very important to know how numeric values are expressed.
As: The chemical symbol of Arsenic.
ASEPTIC: Free from the living germs of disease, fermentation, or putrefaction.
ASYNCHRONOUS: Not occurring at the same time.
ATOM: The general definition of an ion is an atom with a positive or negative charge. Electron is
the name of a negatively charged atomic particle.
ATOMIC NUMBER: The number representing an element which corresponds with the number of
protons within the nucleus.
ATOMIC ORBITAL: The region where the electron of the atom may be found.
AVOGADRO’S NUMBER: Is the number of particles in a mole of a substance ( 6.02x10^23 ).
B
BACKFLOW PREVENTION: To stop or prevent the occurrence of, the unnatural act of reversing
the normal direction of the flow of liquid, gases, or solid substances back in to the public potable
(drinking) water supply. See Cross-connection control.
BACKFLOW: To reverse the natural and normal directional flow of a liquid, gases, or solid
substances back in to the public potable (drinking) water supply. This is normally an undesirable
effect.
BACKSIPHONAGE: A liquid substance that is carried over a higher point. It is the method by
which the liquid substance may be forced by excess pressure over or into a higher point.
BACTERIA: Small, one-celled animals too small to be seen by the naked eye. Bacteria are found
everywhere, including on and in the human body. Humans would be unable to live without the
bacteria that inhabit the intestines and assist in digesting food. Only a small percentage of
bacteria cause disease in normal, healthy humans. Other bacteria can cause infections if they get
into a cut or wound. Bacteria are the principal concern in evaluating the microbiological quality of
drinking water, because some of the bacteria-caused diseases that can be transmitted by
drinking water are potentially life-threatening.
BACTERIOPHAGE: Any of a group of viruses that infect specific bacteria, usually causing their
disintegration or dissolution. A bacteriophage (from 'bacteria' and Greek phagein, 'to eat') is any
one of a number of viruses that infect bacteria. The term is commonly used in its shortened form,
phage. Typically, bacteriophages consist of an outer protein hull enclosing genetic material. The
genetic material can be ssRNA (single stranded RNA), dsRNA, ssDNA, or dsDNA between 5 and
500 kilo base pairs long with either circular or linear arrangement. Bacteriophages are much
smaller than the bacteria they destroy - usually between 20 and 200 nm in size.
BARITE: Processed barium sulfate often used to increase drilling fluid densities in mud rotary.
BAROMETER: A device used to measure the pressure in the atmosphere.
BASE: A substance that accepts a proton and has a high pH; a common example is sodium
hydroxide (NaOH).
BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE (BAT): A level of technology
based on the best existing control and treatment measures that are economically achievable
within the given industrial category or subcategory.
BEST MANAGEMENT PRACTICES (BMPs): Schedules of activities, prohibitions of practices,
maintenance procedures, and other management practices to prevent or reduce the pollution of
waters of the U.S. BMPs also include treatment requirements, operating procedures and
practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from
raw material storage.
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE (BPT): A level of
technology represented by the average of the best existing wastewater treatment performance
levels within an industrial category or subcategory.
BEST PROFESSIONAL JUDGMENT (BPJ): The method used by a permit writer to develop
technology-based limitations on a case-by-case basis using all reasonably available and relevant
data.