An employee was cleaning in a confined space using the lance (hose) of a 20,000-psi water blasting pump when they lost control of the water lance. The employee went to shut off the unit by raising their foot off of the control pedal but the stream of pressurized water cut through their personal protective equipment (PPE), resulting in a laceration near their ribs on the left side of their torso. The employee was hospitalized and required surgery.