Inorganic mercury can enter water from natural deposits, refineries, and runoff from farmland.
In Florida, Mercury (inorganic) was reported by 67 community water systems serving about 771,000 people. 1 of those readings were above the federal legal limit, together serving 282,556 people. It was measured by 1,559 systems in all, so it was detected in 4% of the systems that tested for it.
The highest reading relative to the limit was at Lee County Utilities in Lee County, at 10000% of it.
Where it comes from: Erosion of natural deposits; discharge from refineries and factories; runoff from landfills and croplands.
Enforceable. A utility must stay at or under this.
Health-based, not enforceable. Often lower than the limit, sometimes zero.
California OEHHA PHG (1999) For comparison the legal limit is 2 ppb.
Health effects the EPA associates with it: Kidney damage.
Water at or under the legal limit meets federal safety standards. A reading above a health goal is not the same as being unsafe, and health goals are set purely on health without regard to cost or treatability. Both are shown so the margin is visible either way.
Showing the 25 highest of 67 systems that reported Mercury (inorganic).
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.