Sediment Primary or Secondary, with minimum depth. For a flow rate of 164.5 m3/day design that ensures a retention time of 1.5 hours.
Drawing labels, details, and other text information extracted from the CAD file (Translated from Galician):
Viewnumber, Sheetnumber, Diffuser screen, Energy dissipator, Diffuser screen, Energy dissipator, Diffuser screen, Rebal pipe, Goes percolator filter, Diffuser screen, Projection of landfill, Sediment plant, Scale, section, Scale, section, Scale, Diffuser screen, It comes from desarenador, Metal landfill