TREATMENT PLANT AND METHOD FOR DESIGNING TREATMENT PLANT

Provided is a technology of preventing an increase in size of a treatment plant, which may be caused when a safety clearance for the prevention of spread of a fire is set, and restraining an increase in designed fire-extinguishing water usage. A treatment plant for handling a flammable liquid includes: an equipment placement region in which a plurality of equipments configured to handle the flammable fluid are placed, the equipment placement region being divided into four or more firewater supply sections. A plurality of fire-extinguishing water supply facilities are provided to the firewater supply sections, respectively, the fire-extinguishing water supply facilities each being capable of, when a fire occurs in the firewater supply sections, simultaneously supplying fire-extinguishing water to a fire-occurrence section and an adjacent section.