ob

Cross Connections
(Cont'd.)

Lawn Sprinkiers

On a !arge number of lawn
‘sprinkler installations the
sprinkler head is below the
ground level. Water which
may Nave been in contact
with fertilizers anc weed
killers can then be back-
siphoned through a leaky
valve into the potable water
system.

4

Irrigation Pumping Systems
On many farms water is
pumped from irrigation water
channels intc the sprinkler
system. A large number of
these installations are also
connected to the domestic
water system for times when
there is littia 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
partialiy open crossover
vaive.,

Fire Sprinkler Systems

Ona large number of fire
sprinkler systems there is a
hook up connection tor

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 protected, it is
possible for the pumper to
pump this “wet" water back
into the city's domestic
water supply.

City Main