Water Quality Data and Pollution Sources - Investigations in Environmental Geology - page 214

b. What steps are required to determine the background
concentration of chromium in a watershed with a chrome-
plating factory?

bottled water, micron filtration (screens with micro-
scopic holes) remove most chemicals and microbes. To
remove Cryptosporidium cysts, the largest hole in the fil-
ter must be one micron.
Although the EPA sets the standards for public
drinking water supplies, the FDA (Food and Drug
Administration) sets those for bottled water (based on
EPA standards). The FDA regulates bottled water as a
packaged food and sets the quality and identity stan-
dards and requirements for processing and bottling.
Carbonated water, soda water, seltzer water, sparkling
water, and tonic water are not regulated as bottled water but
as soft drinks. Bottled water sold in the United States,
including those from overseas, must meet the FDA
standards for physical, chemical, microbial, and radio-
logical contaminants.
There are many types of bottled water according
to the Code of Federal Regulations (21 CFR 165.110
(a)(2)). See also sterilized and purified waters above.
Bottled water or drinking water is water
intended for human consumption, sealed in bottles,
with no added ingredients (except safe antimicrobial
agents and fluoride).
Other types of bottled water are:

6. List three microrganisms that indicate contamination by
animal wastes (In addition to Tables 13.1 and Table 13.6, see
the Introduction to water Resources and Contamination.)

PART C. BOTTLED WATER AND WATER
PURIFICATION
Introduction
Bottled water has become a popular drink choice in the
United States because it might be better tasting, safer,
or more readily available than some tap water or
because some people seek an alternative to soft drinks
and other beverages (USEPA, 2005). Most bottled water
comes from ground water, either from wells or springs;
the remainder comes from surface water such as lakes
and rivers—in some cases from public water systems.
The taste of both bottled and tap water depends on the
source (e.g., calcium and magnesium minerals add fla-
vor and body) and the treatment^), particularly the dis-
infection process, which inactivates disease-causing
organisms but might leave a taste.
Bottled water from a ground water aquifer is
obtained from a well or spring (possibly tapped by a
well) and may be labeled as artesian if it comes from a
confined aquifer. Distilled water from a surface or
groundwater source is condensed after boiling to steam.
The process kills microbes (including Cryptosporidium)
and removes natural minerals (and much of the taste)
and some organics.
Tap water is usually disinfected by chlorine or
chloramine, because of the effectiveness, cost, and the
continuing protection provided while in pipes of
municipal water systems and in the home. Some tap
water also uses ultraviolent (UV) light or ozone.
Ozone is the preferred disinfectant for bottled water
because it does not leave a taste and the sealed bottle
does not need continuing disinfection. Other bottled
water is disinfected using UV light or chlorine dioxide.
Ozone (and UV light) kills most microbes depending
on the dosage.
Sterilized water or sterile water is water that is
free from all microbes. Purified water is essentially free
of chemicals (TDS < 10 ppm) and might be produced
by distillation, deionization, or by reverse osmosis
(RO). In the latter process, water is forced through a
membrane leaving behind all contaminants (minerals,
organic and inorganic chemicals, color, turbidity, and
microbes). Purified water may also be referred to as
demineralized water; or distilled water if purified by
distillation, deionized water if purified by deioniza-
tion, or reverse osmosis water if purified by RO. For

artesian water or artesian well water —water from a
well tapping a confined aquifer in which water stands
above the height of the top of the aquifer,
mineral water —water containing not less than 250 ppm
TDS that originates from a geologically and physically
protected underground water source, with no added
minerals, and constant levels and proportions of min-
erals and trace elements. Mineral water is labeled as
"low mineral content" if it is < 500 ppm TDS or as
"high mineral content" if TDS > 1,500 ppm.
sparkling bottled water —water that after treatment
and possible replacement of CO2 contains the same
CO2 as it had when it emerged from the source (com-
pare with sparkling water, above, that is regulated as a
soft drink).
spring water —water derived from underground for-
mation from which water flows naturally to surface
(may also be collected through a borehole).
well water —name of water derived from a well (dug
or drilled).

Also, if bottled water comes from a community
water system, it will be labeled "from a community
water system" or "from a municipal source."
Note that bottled water meets the EPA's Sec-
ondary Drinking Water Standards (e.g., chloride—
250 mg/L and TDS 500 mg/L) except for mineral water.
Bottled water that is certified by NSF International
indicates that the bottler complies with all FDA
requirements. Members of the International Bottled
Water Association (IBWA) meet their trade associa-
tion's "model code." To learn more about a bottled
water and specific contaminants, contact the bottler
through the contact information provided on the bottle.