The following words and terms, when used in this
document have the following meanings, unless the context clearly
indicates otherwise. The definitions for these terms were extracted
from Rules and Regulations for Public Water Systems; Glossary,
Water and Wastewater Control Engineering; State Source Water
Assessment and Protection Programs Guidance; Susceptibility
Assessment Document, andTitle 40 Code of Federal
Regulations.
Alphabetical Index
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
action levels—used in place of MCLs. Triggers
additional requirements but exceeding action levels does not
constitute a violation as does exceeding an MCL.
acute—typically used in the phrase,
contaminants with acute health effects, which is sometimes
abbreviated to acute contaminants. Acute health effects,
as used in the drinking water program, are those which occur
shortly after exposure to a drinking water contaminant,
i.e., usually a matter of hours or days.
chronic—typically used in the phrase,
contaminants with chronic health effects, which is
sometimes abbreviated to chronic contaminants. Chronic
health effects, as used in the drinking water program, are those
which occur over many years. The health risk for these contaminants
is usually estimated over a 70-year period.
community water system—a public water system
with a potential to serve at least 15 residential service
connections on a year-round basis or serves at least 25 residents
on a year-round basis.
connection—a single family residential unit
or each commercial or industrial establishment to which drinking
water is supplied from the system.
contaminant source inventory—the process of
identifying and inventorying contaminant sources within delineated
source water protection areas through recording existing data;
describing sources within the source water protection area;
identifying likely sources for further investigation; collecting
and interpreting new information on existing or potential sources
through surveys; and verifying accuracy and reliability of the
information gathered.
contamination—the presence of any foreign
substance (organic, inorganic, radiological, or biological) in
water, which tends to degrade its quality and can constitute a
hazard or impair the usefulness of the water.
conveyance—refers to canals, aqueduct, or
piping that carries water from the intake or well
to the general area of the distribution system. It does not include
the distribution system itself or storage tanks, treatment plants,
or other infrastructure associated with the distribution
system.
cross-connection—a physical connection
between a public water system and either:
- another supply of
unknown or questionable quality,
- any source which may contain contaminating or polluting substances, or
- any source of water treated to a lesser degree in the treatment process.
cryptosporidium—a protozoan associated with
the disease cryptosporidiosis in humans. The disease can be
transmitted through ingestion of drinking water, person-to-person
contact, or other exposure routes. Cryptosporidiosis may cause
acute diarrhea, abdominal pain, vomiting, and fever that lasts 1-2
weeks in healthy adults, but may be chronic or fatal in
immunocompromised people.
detection—some amount of contaminant was
found, not necessarily in an amount that exceeds the MCL.
drinking water—all water distributed by any
agency or individual, public or private, for the purpose of human
consumption or which may be used in the preparation of foods or
beverages or for the cleaning of any utensil or article used in the
course of preparation or consumption of food or beverages for human
beings. The term "drinking water" shall also include all water
supplied for human consumption or used by any institution catering
to the public.
drinking water standards—the commission rules
covering drinking water standards in §290.101—290.121
(relating to Drinking Water Standards Governing Drinking Water
Quality and Reporting Requirements for Public Water Supply
Systems).
Drinking Water State Revolving Fund—under
section 1452 of the Safe Drinking Water Act (SDWA), the EPA awards
states capitalization grants to develop drinking water revolving
loan funds that help finance drinking water system infrastructure
improvements and source water assessment and protection programs as
well as enhance operations and management of drinking water systems
and other activities that encourage PWS compliance and protection
of public health. In Texas, the drinking water state revolving fund
is administered by the Texas Water Development Board.
E. coli.—Escherichia coli. A bacteria which
can cause acute intestinal distress.
exposure—contact between a person and a
chemical. Exposures are calculated as the amount of chemical
available for absorption by a person.
fecal coliform—a bacteria used to indicate
the presence of other disease-causing organisms.
fibers per liter—the number of fibers found
in one liter of water and is the unit of measurement for asbestos.
MFL is the abbreviation for million fibers per liter.
fluoride—in drinking water decreases the
incidence of tooth decay when the water is consumed during the
period of enamel calcification. Excessive quantities in drinking
water consumed by children during the period of enamel
calcification may cause a characteristic discoloration (mottling)
of the teeth.
Giardia lamblia—a protozoan, which can
survive in water for one to three months, associated with the
disease giardiasis. Ingestion of this protozoan in contaminated
drinking water, exposure from person-to-person contact, and other
exposure routes may cause giardiasis. The symptoms of this
gastrointestinal disease may persist for weeks or months and
include diarrhea, fatigue, and cramps.
G/L—micrograms per liter. Roughly equivalent
to ppb.
hydraulic—refers to fluid and is used in this
document in the context of how water or waterborne contamination
can move overland flow to groundwater, or vice versa.
hydrogeologic—usually refers to the geologic
characteristics that influence the underground flow or movement of
water, as in hydrogeologic characteristics of the
aquifer.
hydrologic—refers to water, and is often used
to refer to the natural geographic characteristics affecting the
overland flow of water, as in hydrologic
characteristics.
intake—refers to surface water intakes, as
distinguished from wells, which refers to groundwater
intakes.
maximum contaminant level—is defined in the
SDWA as the maximum permissible level of a contaminant in water
which is delivered to any user of a public water system.
maximum contaminant level goal (MCLG)—the
level of a contaminant in drinking water below which there is no
known or expected risk to health.
MCL violation—finding a contaminant in an
amount greater than that allowed by the EPA.
mg/L—milligrams per liter. Roughly equivalent
to ppm.
ND—not detected.
NM—not measured.
NTU—Nephelometric turbidity units.
nitrates—inorganic compounds that can enter
water supplies from fertilizer runoff and sanitary wastewater
discharges. Nitrates in drinking water are associated with
methemoglobinenemia, or "blue baby syndrome" which results from
interferences in the blood's ability to carry oxygen.
noncommunity water system—any public water
system which is not a community system.
nonregulated—contaminants which require
monitoring but do not have MCLs.
nontransient/noncommunity water system—a
public water system that is not a community water system and
regularly serves at least 25 of the same persons at least six
months out of the year.
organics—chemical molecules that contain
carbon and other elements such as hydrogen. Organic contaminants of
concern to drinking water include chlorohydrocarbons, pesticides,
and others.
PAH—polycyclic aromatic hydrocarbons. Found
in fossil fuels and a byproduct of burning coal and oil. Some may
cause cancer and have developmental and reproductive effects.
PCB—polychlorinated biphenyl. Commonly used
in electrical transformers. May cause cancer as well as problems
with the skin, liver, and with hearing and vision.
PCi/l—Picocuries per liter. Unit of
measurement for radioactive substances. A pCi/l is equivalent to
two atoms disintegrating per minute per liter.
PPB—parts per billion. Roughly equivalent to
g/l .
PPM—parts per million. Roughly equivalent to
mg/l.
PQL—practical quantitation level. The amount
at which laboratories can accurately determine quantity of a
substance.
per capita—per person; generally used in
expressions of water use, gallons per capita per day (gpcd).
phthalate—Used in PVC pipes and other
plastics. May cause cancer.
point-of-use water treatment—refers to
devices used in the home or office on a specific tap to provide
additional drinking water treatment.
point-of-entry water treatment—refers to
devices used in home where water pipes enter to provide additional
treatment of drinking water used throughout the home.
public water system—a system for the
provision to the public of piped water for human consumption, which
includes all uses described under the definition for drinking
water. Such a system must have a potential for at least 15 service
connections or serve at least 25 individuals at least 60 days out
of the year. This term includes any collection, treatment, storage,
and distribution facilities under the control of the operator of
such system and used primarily in connection with such system; and
any collection or pretreatment storage facilities not under such
control which are used primarily in connection with such system.
Two or more systems with each having a potential to serve less than
15 connections or less than 25 individuals but owned by the same
person, firm, or corporation and located on adjacent land will be
considered a public water system when the total number of
individuals served by the combined systems total 25 or more at
least 60 days out of the year. Without excluding other meanings of
the terms "individual" or "served," an individual shall be deemed
to be served by a water system if he lives in, uses as his place of
employment, or works in a place to which drinking water is supplied
from the system.
radionuclides—elements that undergo a process
of natural decay. As radionuclides decay, they emit radiation in
the form of alpha or beta particles and gamma photons, which can
cause adverse health effects such as cancer. Because of this,
limits are placed on radionuclide concentrations in drinking
water.
regulated—contaminants that require
monitoring with specific MCLs set by the EPA.
risk—the potential harm for people exposed to
chemicals. In order for there to be risk, there must be both hazard
and exposure.
SOC—synthetic organic compound. Chemicals
commonly used in pesticides, herbicides, plastics, and fuels.
sanitary control easement—a legally binding
document securing all land within 150 feet of a public water supply
well location from pollution hazards. This document must fully
describe the location of the well and surrounding lands and must be
filed in the county records to be legally binding.
source water protection area—the area
delineated for one or more source water intakes or wells for the
purpose of defining the geographic boundaries of a source water
assessment. A wellhead protection area is an example of an SWP
area.
subwatershed—a topographic boundary that is
the perimeter of the catchment area of a tributary of a stream.
susceptibility analysis—an analysis to
determine, with a clear understanding of where the significant
potential sources of contamination are located, the susceptibility
of the PWS(s) in the source water protection area to contamination
from these sources. The analysis will assist the state in
determining which potential sources of contamination are
"significant."
THM—trihalomethane. A byproduct of the
disinfection process which have certain health effects.
transient noncommunity water system—a public
water system that is not a community water system and serves at
least 25 persons at least 60 days out of the year, yet by its
characteristics, does not meet the definition of a nontransient
noncommunity water system.
treatment technique—a specific treatment
method required by the EPA to control the level of contaminant in
drinking water. In specific cases, where the EPA has determined it
is not technically or economically feasible to establish an MCL,
the EPA can instead specify a treatment technique.
total Coliform—bacteria that are used as
indicators of fecal contaminants in drinking water.
toxicity—the property of a chemical to harm
people who come into contact with it.
turbidity—suspended materials which cause
water to become cloudy.
VOC—volatile organic compound. Chemicals that
evaporate into the air and are commonly found in gasoline, paint,
solvents, plastics, and adhesives.
watershed—a topographic boundary area that is
the perimeter of the catchment area of a stream.
watershed area—a topographic area that is
within a line drawn connecting the highest points uphill of a
drinking water intake, from which overland flow drains to the
intake.
well—refers to groundwater intakes including
the well structure (i.e., casing, etc.) and wellhead.
wellhead protection area—the surface and
subsurface area surrounding a well or well field, supplying a PWS,
through which contaminants are reasonably likely to move toward and
reach such water well or well field.
