Disinfection of Storage Facilities - Disinfection of Pipelines and Storage Facilities Field Guide - page 75

2. Amount of chemical from Table 5-3 for 65% calcium
hypochlorite
1.5 kg
3. Chemical strength factor is Table 5-3 strength/strength
in example
65% calcium hypochlorite ÷ 65% calcium hypochlorite = 1
4. Volume used in Table 5-3
100 m 3
Plug these values into the calculator.
250 1 ÷ 100 = 3.75 kg of 65% calcium

hypochlorite

× 1.5 ×

Surface Application Method
In this method, a 200 mg/L chlorine solution is applied to all
surfaces within the storage facility that will be in contact with
the water when the facility is completely full.

Chlorination Steps and Precautions
1. Apply the chlorine solution to all exposed surfaces
(Table 5-4) with suitable brushes or spray equipment
(Figure 5-2). Portable spray equipment is adequate for
small tanks.
2. Add chlorine to drains or drain piping so that the chlorine
residual of the pipe when filled with water shall be at
least 10 mg/L. Overflow piping does not need to be chlori-
nated. Make sure the drain line valve is closed to avoid
the need for dechlorination.
3. Allow at least 30 min for contact of the strong chlorine
solution with the treated surfaces.
4. Introduce potable water and remove the water from
treated drains and drain piping.
5. Fill the facility to overflow level with potable water and
return to service.