[holding answer 17 September 2007]: In 2000 the Environment Agency published a non-statutory environmental quality standard (EQS) for fluoride in water. The standard was informed by a review, carried out for the Agency, on the effect of fluoride on a range of aquatic life. This review drew on available research from recognised scientific laboratories and indicated that fluoride affects aquatic life at concentrations at 9.0-350.Omg/l depending on the hardness of the water and the sensitivity of the species tested.
Where public water supplies are fluoridated the concentration of fluoride is maintained at 1.0mg/l, and any discharges of these supplies into the aquatic environment would be further diluted through the process of collection and treatment of waste water. Therefore the environmental impact would not be expected to be significant.