At a convenient time the priest or a deacon should return to the spot and clean the area with water and a cloth to blot up the area (traditionally three times) the water that is soaked up is placed in a special sink in the sacristy called a sacrarium, or piscina, which drains directly into the ground rather than into the sewar system. If there is no sacrarium a decent spot like a plant in a pot, or a garden can recieve the soaked up water. The same thing happens with old holy oils and other blessed or consecrated items that are burned and disposed of in the sacrarium in order that they not fall into the hands of someone will may use them in a profane way.