Almost half of the pools tested through the summer 2011 Healthy Pools campaign showed improper water chemistry.

Approximately 1,500 pools were tested and results showed that 47 percent of pools had pH outside the recommended range of 7.2-7.8 and 54 percent had free chlorine values outside the recommended range of 1-3 parts per million.

The majority of the pools (78 percent) were backyard pools. Testing was conducted via test kits available for free from the Healthy Pools campaign, a project of the Centers for Disease Control and Prevention and the Water Quality and Health Council, an independent group sponsored by the Chlorine Chemistry Division of the American Chemistry Council. Funding for test kits was provided through a donation from the Hach Company. Read more...