Brine and therapeutic mud are used at the Ustroń resort for medical treatment. Rheumatology, the main therapeutic profile there, and the properties of brine sources drilled in the 1970-s justify the importance of the brine baths. Removal of spent brine has been an unsolved problem. Controlled discharge of saline water to the Vistula and Olza Rivers and the thermochemical method were unacceptable. Injecting spent brine into underground permeable strata has proved effective. The author discusses the technology of this method.