The UV lights disinfect the water, while keeping chemical additives to a minimum. Ironically, the end product is too pure. Most water treatment systems have to work hard to reduce the amount of chlorine to safe levels. Couran Cove Resort water has to have a little chlorine added to meet government standards. There are drawbacks to the filtration process.
Some waste water is produced.
But it is put to good use. Water that doesn't pass through the filters is stored and used to irrigate the native plants. From there, of course, it seeps back into the waterable and the whole process starts again.