EPA Warning about using chlorine in bodies of water such as swimming pools. The dangers of THMs in swimming pools produced by using chlorine. We have researched this dangerous product right from the EPA web site for your information. The first EPA web address is about what are THMs and what causes THM it to appear in water: http://www.epa.gov/envirofw/html/icr/tuxdbp/tthm.html   This next EPA web site speaks of THMs can lead to cancer and other dangers caused by this product: http://www.epa.gov/EPA-WATER/2000/June/Day-21/w9534.htm   The next is a Canadian Warning about chlorine in water: http://www.ottawacitizen.com/national/981124/2045508.html   You are aware of the disease Legiona, Doctor Victor L. Yu recommends Copper/Silver ionization is the long term disinfection modality of choice:   This web site of Legionella is http://www.legionella.org/ The EPA reports are very favourable to the use of Superior Aqua Ionization systems. Over the years, the use of corrosive sanitizes can add to the expense of the pools over all operational cost. Copper/silver Ions may be the best answer for your safety and health protection. Also to greatly reduce the cost of the operation of swimming pool.