Method for recycling plate-making processing waste solution

A method of recycling waste liquid from a plate-making process for a planographic printing plate precursor, the method comprising:

• performing, in an automatic developing machine for developing a photosensitive planographic printing plate precursor after exposure to light, a plate-making process using a development replenisher liquid, the planographic printing plate precursor including a radical-polymerizable image recording layer on a support, the plate-making process including developing a planographic printing plate precursor after exposure to light, the development replenisher liquid including at least one selected from the group consisting of anionic surfactants having a naphthalene skeleton and nonionic surfactants having a naphthalene skeleton at a total content of from 1% by mass to 10% by mass, the development replenisher liquid including no organic solvent having a boiling point within a range of from 100° C. to 300° C. or including organic solvent having a boiling point within a range of from 100° C. to 300° C. at a total content of no more than 2% by mass, and the development replenisher liquid having a pH of from 10 to 13;
• concentrating, by evaporating, the plate-making process waste liquid discharged during the plate-making process using a waste liquid concentration device, such that the ratio of the volume of the plate-making process waste liquid after concentration to the volume of the plate-making process waste liquid before concentration is within a range of from 1/10 to 1/2, thereby separating the plate-making process water liquid into water vapor and a waste liquid concentrate;
• condensing the separated water vapor to obtain regenerated water;
• and
• using the obtained regenerated water as at least one of diluent water for preparation of the development replenisher liquid for the automatic development machine or rinse water for the automatic developing machine.