Serious Cross
Contamination In Yard Hydrants
by
Herb Hoeptner, Hoeptner Perfected Products
Due
to the deaths associated with e-coli outbreaks and other
pathogens that have contaminated our water supplies, there has
been great concern regarding cross contamination between the
potable water supply and the soil, which carries animal
by-products, fertilizers and other hazardous materials.
Most
of us are familiar with a standard “weep hole” Yard
Hydrant as they have been around for years. Hundreds of
thousands of them are sold each year. They are used in
campgrounds, RV parks, ranches, farms, gardens and anywhere
water is needed away from a building. However, most of us are
unaware of the serious cross contamination potential
associated with the weep hole at the base of the hydrant. The
common weep hole yard hydrant consists of a head for attaching
a hose, a riser pipe and a shutoff valve deep below the frost
level. The term “weep hole” is derived from the fact that
when the weep hole hydrant is shut off, a hole in the side of
the valve opens to drain all water from the riser into the
soil below the frost line, much like a Stop and Waste Valve.
Most
state’s agencies recognize the cross contamination potential
anytime a hose is connected to a hydrant. Hoses have the
ability to be placed in high hazard environments, such as
stock tanks, pesticide tanks or even lying on the ground in
mud puddles. Back Siphonage will cause these hazardous
materials to be sucked back into the water supply. Back
siphonage can occur whenever a supply line is broken or
drained for repair. In addition, yard hydrants create a back
siphonage each and every time they are shut off, as the mere
act of draining the riser, creates a siphon at the hose bib.
Because of this, many states have required vacuum breakers to
be attached to all hydrants where a hose could be attached.
Naturally this prevents cross contamination during back
siphonage should the hose be placed in a contaminated
environment.
What
many agencies are starting to realize is that there still
exists a severe cross contamination potential associated with
the weep hole being in contact with the soil. Because these
weep hole hydrants function much the same way as a Stop and
Waste Valve, they suffer the same cross contamination issues.
For example, if the stopper in a standard “weep hole”
hydrant ever leaks, it is undetectable at ground level as it
is leaking out the weep hole deep into the ground. The hydrant
drips continuously throughout the day & night, and from
the surface no one is aware the hydrant is leaking. When a
back siphonage condition occurs that leak out will become a
leak in, sucking contaminated muddy water into the supply
line. If the hydrant is located in a horse or cow barn, animal
by-products will leach into the potable water supply. In
states where the ground water level fluctuates, this problem
is exacerbated by the fact that during the summer months, when
the water table rises above the weep hole, the riser will be
filled with soiled lake water that will be consumed by the
public. Each time the hydrant is shut off and the weep hole
opens, contaminated lake water will migrate into the hydrant.
Each time the hydrant is turned on, that contaminated migrated
water enters the potable water supply system. Outside drinking
fountains operate the same way. During the summer months each
time the fountain is turned on, the first drink of water is
nothing but soiled, possibly contaminated, water.
The
liability toward each state became such a concern that many
states created their own yard hydrant requirements. Initially,
states implemented requirements to isolate weep hole hydrants
from the potable water supply. These requirements included
installing a testable RPP backflow preventer upstream of the
hydrant and then tagging the hydrant “danger unsafe
water”. This solved two major concerns. First, it protected
the potable water supply from siphoning contaminated water
into the public water system, and secondly, it attempted to
notify the public not to use the hydrant for any potable
source. The downside to this approach was the cost associated
with the purchase and installation of a testable RPP backflow
preventer, the difficulty in finding a location for the RPP
device to keep it from freezing, the added cost in annual
inspection and testing of the RPP device, and the fact that
the weep hole yard hydrant is not fit for potable water. RV
parks & campgrounds were especially hard hit, as they
required potable water from their hydrants.
Manufacturers
soon developed a new breed of yard hydrants to solve the
problems associated with the new requirements imposed on weep
hole hydrants. These new hydrants are called Sanitary Yard
Hydrants.
A
Sanitary Yard Hydrant works much the same way as a Weep Hole
Hydrant in that when they are shut off, the water in the riser
drains down and out a hole located below the frost line to
prevent freezing. However, instead of draining out a hole and
into the soil, the Sanitary Hydrant drains into a sealed tank.
When the hydrant is turned on again, the water in the tank is
expelled leaving the tank empty to repeat the cycle when the
hydrant is again shut off. Because the sanitary hydrant drains
into a tank there is no cross contamination with the soil.
Because the soil is not required for drainage the hydrant can
be placed in any soil condition, even clay. With the addition
of a vacuum breaker at the hose connection, the Sanitary Yard
Hydrant protects the potable water supply & public from
cross contamination from the soil & from the hose.
The
problem for the state and local code officials was the cost,
manpower, and liability in having to develop their own
approval process and testing each manufacturer’s device for
approval. In turn, the varying requirements by each state made
it difficult for manufacturers to make one product for all
states.
ASSE
realized the need to develop a national standard to help
states avoid this liability and give manufacturers the ability
to meet one set of requirements. After six years of debate and
research by code officials, manufacturers, engineers,
consultants, and the public, ASSE’s Sanitary Yard Hydrant
Standard 1057 was completed. This standard requires that the
yard hydrant not drain directly into the ground and that it
must have a back flow preventer if a hose is capable of
attachment. In addition, it stipulates minimum required
pressure and flow capabilities and ensures proper freeze
protection. It also stipulates, the manufacturers must test
their hydrants at an approved and regulated test lab.
This
standard reduces the liability, manpower, and costs for the
state agencies to ensure proper protection of the water supply
and the public. At the same time it helps manufacturers to
have a base line from which to develop and improve yard
hydrants in general.
With
the continued efforts by states for clean, safe, potable water
and the high liability associated with cross contamination,
greater concern must be given to the proper selection,
installation and use of yard hydrants.
Herb
Hoeptner has been designing Yard Hydrants for over 15 years.
Five of his thirty-five plus patents are for Yard Hydrants. He
has been on the American Society of Sanitary Engineers (ASSE)
Working Groups for over 10 years. As a member of the Working
Group he helped develop the 1011, 1019, 1052 and 1053 backflow
and wall hydrant standards. For the past six years he was
chairman of the Working Group to develop the ASSE 1057
Sanitary Yard Hydrant Standard.
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