O
By Erika Henderson, Director of Research for Pittsburg Tank & Tower, Inc.
Can Parasitic Worms Get
Into Drinking Water Tanks?
12
NCRWA.COM |
Winter 2014
feature
n August 26, 2013, a small Oklahoma town was advised not to use
the tap water for cooking or drinking, because red worms had been
found in the town’s drinking water supply. The Oklahoma Department
of Environmental Quality (DEQ) conducted an investigation and
determined that midge flies entered the system through sand filters at
the water treatment plant. The flies laid their eggs in the filters and
when the eggs hatched, the red worms simply swam into the water
supply.
[1]
Fortunately, these worms were not parasitic, but several
parasitic worms could get into drinking water systems: roundworms,
flukes and tapeworms.
These parasitic worms are transmitted by direct contact with their eggs,
consuming a host that has the parasitic eggs, or consuming the feces
of hosts that contain their parasitic eggs. Once consumed, the parasitic
eggs hatch and attach themselves to the intestines. Some stay in the
intestines, but others travel to various organs and parts of the body to
cause damage, while they continue to grow and multiply!
HOSTS AND THEIR ENVIRONMENTS
Hosts can include: aquatic life, insects, birds, rodents and other animals.
They can gain access to drinking water through openings on tanks.
Aquatic hosts can travel through the inlet or outlet pipes depending
on the tank’s source of water. Aquatic life is often found in tanks that
receive their water from lakes, streams, rivers or other waterways. A
few years ago, more than 50,000 gallons of mud and aquatic life were
removed from a two-million gallon tank in New York, and in Georgia, a
fish swam past the camera during an inspection. These are all potential
parasitic worm hosts!
Other hosts can gain access by holes in the roof, shell, or floor. Gaps
between the roof and shell, vents or overflows with torn or missing
screens can allow insects, birds, and other small animals into the tank.
If birds and insects are in the tank, then their feces and the possibility
of parasitic eggs are also in the tank. Human beings that consume the
contaminated water become the next host, where the parasitic worm
continues to grow in them for years. Another disturbing fact is that
these openings often go unnoticed until an inspection is performed, that
means this potential risk could go unnoticed for years!
Stagnant water also contributes to contaminated water. The stagnant
water creates a list of microscopic organisms and bacteria that lures
potential hosts into the tanks. Stagnation occurs when water is separated
into layers arranged by density; the least dense and warmer water
sitting above the denser cooler layers of water coming in. The layers are
caused by differences in temperature, pressure, and pH. These unmixed
layers cause water quality to deteriorate and age, increasing bacterial
growth. Flies, mosquitoes, water fleas and other insects and crustaceans
are attracted to the bacterium and birds are attracted to the insects.
MEET THE PARASITES
Roundworms:
Water fleas are possible hosts to the Dracunculus larva,
a type of roundworm that causes a horrific disease known as guinea
worm disease (GWD). Once the infected water fleas are ingested,
stomach acid dissolves the water flea, but not the Dracunculus larva
that hatches and travels to connective tissues. Often, no symptoms are
noticed until approximately one year later, when the disease and worm
presents itself with a painful, burning sensation, as a blister on the skin
forms. About a week later, the blister ruptures exposing one end of the
worm. Often, the infected person immerses the affected area in water to
relieve the pain, but then hundreds of thousands of larvae contaminate
the water, allowing the cycle to repeat again. To extract the worm, a
person must wrap the live worm around a piece of gauze or stick. The
process can take hours to months and great pain accompanies it.
[2]
Other parasitic roundworms include: pinworms, hookworms, Ascaris,
Baylisascaris, and Stronglyloides Stercoralis. Pinworms are said to be
