The Marine Corps is testing a new method of quickly purifying water. Once perfected, the system will enable Marines in the field to draw potable water from any source available. The Individual Water Purification System (IWPS) Block II is an upgrade from the version Marines now use. The current water purifier eliminates bacteria and cysts, but not viruses – and it takes 15 minutes to work. In contrast, IWPS Block II is better at filtering out bacteria and viruses, and does not require an internal cartridge. The Marines expect to field IWPS Block II sometime next year.