Brochure

Lawn Sprinklers
On a large number of lawn
sprinkler installations, the sprin-
kler head is below the ground
level. Water which may have
been in contact with fertilizers
and weed killers can then be
backsiphoned through a leaky
valve into the potable water
system.
Irrigation
Pumping Systems
On many farms water is
pumped from irrigation water
channels into the sprinkler sys-
tem. A large number of these
installations are also connected
to the domestic water system
for times when there is little or
no irrigation water available.
It is possible that the pump
develops more pressure than
there is in the domestic supply
main and the irrigation water
can then be pumped through
a leaky or partially open cross-
over valve.
Fire Sprinkler Systems
On a large number of fire sprin-
kler systems, there is a hook
up connection for the fire truck
pumper to increase pressure
and flow in the sprinkler
system. At times a “wetting
agent” is added to the water
to increase the effectiveness
of the water in combating the
fire. If the system is not pro-
tected, it is possible for the
pumper to pump this “wet”
water back into the city’s
domestic water supply.
Typical
Cross-Connections
City Main
City Main
5
Pump
Irrigation
Water