Section 604.800  Lime or Lime-soda Process

a)         Design standards for rapid mix, flocculation and sedimentation are in Subpart E.

b)         When split treatment is used, an accurate means of measuring and splitting the flow must be provided.

c)         Before installation of lime or lime-soda processes, the community water supply must determine the carbon dioxide content of the raw water to evaluate the efficacy of installing aeration treatment.

d)         Lime must be fed directly into the rapid mix basin or mixing chamber.

e)         Rapid mix detention time must be no longer than 30 seconds, with adequate velocity gradients to keep the lime particles dispersed.

f)         The softening process must include equipment for stabilization of water softened by the lime or lime-soda. 

g)         The use of excess lime is not an acceptable substitute for disinfection. 

h)         The plant processes must be manually started following shut down.