author of Bedikas Hamozone Cehalocho
Translated from Volume 3 of Bedikas Hamozone Cehalocho
(now being prepared for publication in Hebrew)
Summer 5764 (2004)
A Jew residing in New York bought Chasalat-brand lettuce from
Eretz Yisroel and, following the instructions, washed
the leaves well. As an extra precaution, after washing them
he held the leaves up to the light by a window to examine
them and saw that small insects remained on the leaves. He
washed them again, and again found the same phenomenon
— and even after a third washing.
He complained to the company that grows the vegetables and
included a sample of the insects that he found on the
lettuce. However, the expert who examined the sample found
that they were not insects that are found on lettuce, but
small creatures found in water!
"If that's the case," said the man from New York, "let's
check the water."
His quick investigation revealed a shocking finding: In the
tap water were little "pieces of dirt" that were actually
tiny crabs! Checking by his neighbors and in other
neighborhoods, he found similar results: in New York tap
water there are tiny creatures — known as
"zooplankton."
The problem is specifically in New York City drinking water,
which is considered [by the US health authorities] to be of
particularly high quality, since it comes directly from the
Catskill Mountains. In other American cities there is a law
requiring that the water must be filtered before being
distributed to consumers, but in New York City, because the
water is of such high quality, the authorities do not filter
it and it is sent directly from the reservoirs to the
consumer. The longer the water stands in the reservoir, the
higher is the level of infestation.
When the first reports came in from New York, a red light
went on by us. What about our water in Eretz
Yisroel?
A preliminary investigation revealed that the water in Israel
is not filtered either. Here too, most of the water sent to
homes is standing water whose source is the Kinneret, in
which the same creatures are found.
As a result, we launched a broad investigation into the
presence of insects in drinking water in Israel, New York,
and other places. The results follow.
Halachic Perspective
The gemora in Chulin (66:2) teaches that worms
found in cisterns are not included in the prohibition of
insects, and the Shulchan Oruch (Yoreh Deah 84:1)
rules accordingly (on the condition that the water is drunk
directly from the cistern and is not drawn in a vessel).
However, this law applies only to water in a closed cistern
where there is no flow of water. In systems where the water
flows, the insects in the water are prohibited.
When, in 2004, it was discovered that in New York City
drinking water there are clearly visible creatures (their
size is 1 mm.) HaRav Y. S. Eliashiv, HaRav Chaim P.
Scheinberg, HaRav Dovid Feinstein, and other important
rabbonim ruled that these insects are prohibited, since the
reservoirs are fed from flowing water.
Therefore G-d-fearing Jews in those areas installed filters
on their sinks in order not to transgress the prohibition of
eating insects.
Drinking Water in Eretz Yisroel
Water Sources
In standing water such as ponds, cisterns, reservoirs, and
water tanks, zooplankton, which are tiny creatures ranging in
size from 0.1 to 1.0 millimeters, are found. In the Kinneret
for example, hundreds of creatures can be found in each liter
of water. They are usually transparent-to-white and can be
seen easily, even without magnification: Fill a clear glass
or bottle with Kinneret water and look at it against the
light or on a dark surface (such as a black piece of material
or paper). Small creatures can be seen floating in the
water.
In underground water such as aquifers, the water is usually
free of living creatures.
Most of the homes in Israel get their drinking water from the
Kinneret. A minority gets water from aquifers. In Jerusalem,
however, most of the water comes from aquifers and only 20-40
percent comes from the Kinneret.
Water from the Kinneret is transported to settlements
throughout the country, from the north to the south. The
water is transported from the Kinneret via the National Water
Carrier in open canals until the Eshkol Reservoir. In
addition to the zooplankton found in the waters of the
Kinneret, in the reservoir tiny algae, snails, nematodes, and
other creatures develop.
Cleaning Methods
In the reservoir, the water undergoes various cleaning
processes:
Physiochemical processing - Sedimentation. An alum
sulphate solution is introduced into the water which causes
substances floating in the water to sink to the bottom of the
reservoir.
Biological processing. Scavenging fish found in the
water, such as carp, silver carp, and St. Peter's fish, eat
the algae and the creatures in the water.
Chemical processing. Before the water leaves the
reservoir (to the pipes that take it eventually to the
homes), chlorine compounds are introduced into it. The
purpose of these substances is to kill and destroy living
creatures remaining in the water.
Filtering. An advanced filtering system for the
National Carrier is in the final stages of development and
installation. The system is composed of huge sand filters
which draw out the various particles. Then the water passes
through charcoal filters which neutralize the chlorine taste
of the water. This system is scheduled to begin functioning
in September 2006.
After the first three processes, the water reaches a level of
purity of 1 NTU (as compared to the founding period of the
National Water Carrier about forty years ago, when the
standard was 25 NTU). After the filtering system begins
working, it is hoped that a level of 0.5 NTU will be
achieved. This is one of the highest levels of water purity
in the world.
It should be noted that the NTU standard refers to the
general purity of the water and not specifically to living
creatures.
When the water leaves the reservoir, it is 99 percent clean
of living creatures. In other words, it contains an average
of 2 tiny creatures in a liter of water. These creatures are
very tiny and they die and are partially crushed as a result
of the chlorine.
Drinking Water in Eretz Yisroel
The water is transported from the reservoir to the various
cities and towns by an underground piping system that is
altogether 86 kilometers long. In dark, closed places like
pipes, zooplankton do not develop.
The few creatures that remain after the reservoir are
apparently crushed in the pipes and are not found in the
drinking water.
In 5765 we carried out a study under the auspices of the
Institute for Jewish Heritage, in which we studied over 100
samples of water from various settlements in Eretz Yisroel
[Amuka, Atlit, Ashdod, Ashkelon, Beer Sheva, Beit She'an,
Beit Shemesh (several locations), Beitar, Bnei Brak (several
locations), Carmiel, Gush Katif, Haifa, Jerusalem (tens of
samples from various neighborhoods), Kinar, Modiin Illit
(several locations), Netanya, Netivot, Ofakim, Rechasim,
Tveria, Tzefat, and more]. All the samples were found to be
clean, without infestation by living creatures.
Each check involved the filtering of tens of liters of tap
water.
In summary, the tap water in Eretz Yisroel appears to
be clean, and there is no need to filter it.
Drinking Water in New York City
In most of the United States the law requires filtering of
the water before it is supplied to the consumer. However, in
New York City (as well as in Boston and Seattle, that we know
of) the water is considered very high quality, and is not
filtered.
Although the New York water undergoes similar processes to
those undergone by the Kinneret water, an average of ten
zooplankton are found in each liter of water. The water is
chlorinated and this causes the creatures to die and become
partially crushed, but they are easily visible in the water.
Although to the untrained eye they look like little pieces of
dirt, if they are examined carefully or magnified 10 times it
can readily be seen that they are water creatures. Therefore
tap water in New York City must be filtered.
The recommended method for filtering is to use a tightly
woven cloth, preferably doubled, since the force of the water
may push the insects between the threads of the cloth. The
cloth should be replaced or laundered frequently.
Alternately, a commercial filter with holes no bigger than 50
microns, which is installed over the tap, is recommended.
If a central filter for the entire water system of a house,
factory, or restaurant is used, one should use a filter from
a well-known company, which conforms to approved
standards.
The filter should be cleaned and maintained according to the
manufacturer's instructions.
Boiling the water does not destroy the insects.
Drinking Water in Other Countries
We do not have clear information on the state of the water in
other countries, and it is recommended that the water be
checked.
The recommended method for checking is as follows. Cover the
spigot with a tightly woven cloth, and after several days of
use (preferably a week) remove the cloth carefully and place
it in a transparent vessel of water, such as a glass, with
the inner side of the cloth facing the bottom of the glass,
deep in the water. Shake the cloth gently in the water.
Remove the cloth and check the water over a dark background
(e.g. a black cloth or paper). If small white "pieces of
dirt" are found, examine these with a 10x magnification
magnifying glass.
Reserve Water Tanks
Some people in Israel have a water tank on the roof, for
example for Shabbos use. These tanks must be tightly covered
and must be cleaned and disinfected at least once a year.
Instructions for proper maintenance of reserve water tanks
are available from the Gichon Agency in Jerusalem.
