Molybdenum
Overview
Molybdenum is a metal that erodes into groundwater from natural deposits and enters water from mining and industrial use. EPA monitored it nationwide in 2013 to 2015 and has set no limit for it.
In Florida, Molybdenum was found in 130 community water systems serving about 13,041,454 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; mining and industrial discharge.
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), 2012 Edition of the Health Advisories Table. 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: EPA's reference concentration of 40 ppb is set on chronic non-cancer effects.
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
Reverse osmosis removes it. Anion exchange also works, because molybdenum is present as an anion at drinking water pH.
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 130 systems that reported Molybdenum.
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.