The Feb. 23 pump valve failure was discovered during a daily inspection Feb. 24 and resulted in excess fluoride contaminating a 500,000-gallon storage reservoir, the utility said. The associated well and reservoir were taken offline, and the reservoir and five west side pipe systems were flushed until the fluoride levels dropped.
Sun Prairie Utilities notified about 9,000 customers earlier this month that an equipment malfunction caused fluoride levels in some city water to exceed state and federal safe drinking water standards but resulted in no immediate danger to public health.
The maximum level for fluoride is 4 milligrams per liter. Immediately after the valve failure, a test at the well system entry point showed 13.23 mg/L, according to the utility. That was down to 0.56 mg/L by March 6.
Some people who drink water containing too much fluoride can, over the course of many years, get bone disease, including pain and tenderness of bones.
*Original full-text article online at: https://madison.com/news/local/govt-and-politics/equipment-failure-causes-brief-spike-in-fluoride-in-sun-prairie-water-no-danger-to-public/article_3d340fa9-8346-5e62-8b11-c0084c975c0c.html