Strontium
Overview
Strontium is a metal that dissolves into groundwater from rock. EPA classes it as a metal and monitored it nationwide in 2013 to 2015. In 2014 it made a preliminary determination to regulate strontium in drinking water. There is still no federal limit.
In Florida, Strontium was found in 249 community water systems serving about 19,919,559 people. Nobody has set a legal limit for it, so no reading here counts as an exceedance and no utility is required to do anything about it.
Where it comes from: Erosion of natural deposits.
The standards
Enforceable. A utility must stay at or under this.
Health-based, not enforceable. Often lower than the limit, sometimes zero.
EPA Reference Concentration (UCMR 3), Federal Register notice for the preliminary regulatory determinations for contaminants on CCL 3. EPA sets this on chronic exposure. It is not a legal limit and no utility is required to meet it.
Health effects the EPA associates with it: Strontium takes the place of calcium in bone, so EPA's concern centres on skeletal development in infants, children and adolescents whose bones are still forming.
The health goal is set on health alone. The legal limit is set as close to it as is technically and economically feasible, so treatment cost and available technology are written into the number a utility is measured against. A system at or under the limit is meeting the standard it is required to meet. Both numbers are shown so the distance between them is visible.
What removes it
It behaves like calcium, so a water softener captures it by ion exchange, the same way it captures hardness. Reverse osmosis also removes it.
Treatment guidance describes the methods generally used for this contaminant. What your own tap actually carries depends on your plumbing and your service line as much as on the utility, which is what a test at the house tells you and an annual report cannot.
Where in Florida
Highest reported levels
Showing the 25 highest of 249 systems that reported Strontium.
Data Sources
These figures describe water as delivered by each utility, not what your home’s plumbing adds after it arrives. Informational; not a substitute for testing your own tap.