Tests shall be taken before initial issue of water and at regular intervals, so that the chlorine residual can
be determined. If the residual chlorine content is less than 0.4 ppm or less than the amount prescribed by
the Medical Officer, manually add and stir sufficient calcium hypochlorite to the water in the storage tanks
to increase the residual chlorine. Do not drink the rechlorinated water until 30 minutes after the additional
calcium hypochlorite has been added.
Starting Distribution Pump. If this pump is needed for pumping the raw water, a gasoline engine driven
pump is used for distributing the water.
Gasoline Engine Driven Pump. If the gasoline engine driven pump is used to distribute the filtered water,
connect it in the same manner as the electric driven pump. See the instruction plate on the pump engine for starting and
stopping, lubrication, and servicing instructions.
Water Treatment Process. The water treatment process reduces the organic and suspended matter of raw
water to a minimum and produces water suitable for application to the diatomite filter.
Raw water is pumped from its source by the raw water pump through the aspirators (1, fig. 2-27)
to the influent launders (2) from where it overflows into the downcomer tube (13) or mixing zone (4).
The aspirators aerate the water which improves sludge formation.
The flow of water to the influent launder (2) is regulated by valve CV-9 (3, fig. 2-13).
Ferric chloride, pulverized limestone, calcium hypochlorite solution, and when necessary,
activated carbon are added in the mixing zone. (e) As liquid descends through the mixing zone (4, fig. 2-27), it is mixed
by the circular disks (14). The flow is deflected by a series of shallow baffles (11) in the bottom of the erdlator tank and
directed in counter rotating direction into the outer compartment or clarification zone (9). The resulting counter rotation is
reduced but continues at a sufficient velocity to keep the slurry volume, together with the clear water above the slurry