Between January and March 2017, eight residents of a senior living facility located in Wayzata, Minnesota developed a rash suspected to be caused by Pseudomonas aeruginosa after swimming in the facility's pool. Rashes were reported on multiple parts of the body, including the back, chest, arms, and legs. No other symptoms were reported.

Swimming in the pool was statistically associated with illness (7 of 8 cases vs. 8 of 9 controls; odds ratio, 9.6; 95% confidence interval 1.0 to 94.5; p=0.03). Cases reported using the pool for water aerobics, and arthritis classes, often multiple times a week. All cases who reported swimming reported showering immediately after getting out of the pool.

Review of the pool logs found drastic swings in the free chlorine levels on multiple occasions. There were multiple days when no readings were recorded.