Ferric chloride........................... 1
Calcium hypochlorite ................ 1/4
Diatomaceous earth.................. 1/2
Carbon ..................................... 1/10
(The curve for carbon is on the same chart as for limestone and each curve is identified).
Recharging chemical slurry feeder.
(a) When the level of limestone or diatomaceous earth slurry in the feeder reaches the low level
marker, recharge the compartment requiring additional slurry solution.
(b) Recharge the limestone compartment as described In paragraph 2-4, c.(4), except that the
required amount of limestone for recharging is 11 pounds.
(c) Recharge the diatomaceous earth compartment as described in paragraph 2-4, c.(2), except that
the required amount of diatomaceous earth for recharging is 5 1/2 pounds.
Recharging chemical solution feeder tanks. When the level of ferric chloride or calcium hypochlorite
solution, in the solution feeder tanks (5 and 6, fig. 2-10) drops to approximately 4 1/2 inches from the bottom, recharge
the tank requiring additional chemical solution as described in paragraph 2-4.
(a) The aspirator aeration manifold located above the erdlator tank provides preaeration of the raw
water influent to the influent launder (2, fig. 2-29). The gate control valves CV-10 (5, fig. 2-13) and CV-11 (7) in this
manifold are normally open.
(b) The normal operating reading of the pressure gage PG-1 (6) with both valves open is 5 to 7 psi.
If the pressure rises above this reading, it indicates that the aspirators (1, fig. 2-27) are clogged or valves are closed.
Remove the foreign matter from the aspirators to remedy this condition.
(c) If numerous air bubbles are observed on the surface of the water in the erdlator tank, it indicates
that the water is supersaturated with dissolved gases. Partially close or completely close one or both of the gate control
valves CV-10 (5, fig. 2-13) and CV-11 (7) as necessary to remedy this condition. This corrective action increases the
pressure and aeration and releases dissolved gases. Adjust the raw water influent flow as described in paragraph 2-4 b.
(5) Slurry blanket rotation.
(a) The slurry blanket in the erdlator must be kept rotating. Banking of the slurry blanket on the outer
circumference indicates too much rotation. Insufficient rotation is indicated by lack of rotation of the slurry blanket
around and near the outer circumference.
(b) The rotation of the slurry blanket is decreased by moving the agitator drivebelt to a smaller
groove of the motor pulley.
(c) The rotation of the slurry blanket is increased by moving the agitator drivebelt to a larger groove
of the motor pulley.
Change 4 2-55