Since nearly every job presents a different problem, the operator may have to vary the given procedures to fit the
Do not mix dry calcium hypochlorite and activated carbon together. They react violently causing
possible fire or explosion.
The following chemicals are required in the treatment and filtration processes: (a) Ferric chloride as a
Calcium hypochlorite as a disinfectant.
Pulverized limestone as a coagulant aid.
Diatomaceous earth as a filter aid.
Activated carbon as an absorber to control objectionable tastes and odors. The addition of activated
carbon into the limestone compartment is explained in paragraph 2-5c.
Starting Water Treatment Section.
Protect the eyes and skin from direct contact with potentially injurious chemicals and solutions by the
use of chemical-resistant face shields, aprons, and gloves. Be especially careful when opening
containers to avoid inhaling chemical powder. Do not mix calcium hypochlorite and ferric chloride.
When mixed they give off chlorine gas which is an irritant to the respiratory tract and can cause
tracheo-bronchitis, pulmonary edema, or death (in sufficient quantities).
Preventive maintenance. Perform the daily preventive maintenance services (table 3-1). Lubricate the
water purification unit as specified in the current lubrication order.
Preparation of ferric chloride solution.
Initial base charge. The initial base charge for ferric chloride solution as shown on the ferric chloride
solution scale reading (fig. 2-9) is 1 pound of ferric chloride per gallon of water.