Abstract: In overview, the described system provides a mercury-free gas discharge UVC lamp system and in particular a liquid purification system including a treatment container, a treatment volume, and one or more UVC lamps as described hereinafter configured to irradiate the treatment volume. In an embodiment of the invention, the UVC lamp system includes a tubular glass or quartz envelope, evacuated to approximately 200 Torr and slightly backfilled with a noble gas such as Xenon, Argon, or Nitrogen. For end emission, the cylindrical opening in each electrode assembly may be a through-hole capped externally by a quartz window. The radiation flux and dwell time may be adjusted to the type and degree of contamination in the water.