Thallium

Systems reporting it
38
People served
566,870
Over the legal limit
2
Legal limit (MCL)
0.002 ppm

Overview

Thallium is a metal from ore processing and electronics or glass manufacturing.

In Florida, Thallium was reported by 38 community water systems serving about 566,870 people. 2 of those readings were above the federal legal limit, together serving 31,960 people. It was measured by 1,559 systems in all, so it was detected in 2% of the systems that tested for it.

The highest reading relative to the limit was at Plantation Oaks MH & RV Community in Hillsborough County, at 650% of it.

Where it comes from: Leaching from ore-processing sites; discharge from electronics, glass, and drug factories.

The standards

Legal limit (MCL)
0.002 ppm

Enforceable. A utility must stay at or under this.

Federal health goal (MCLG)
0.0005 ppm

Health-based, not enforceable. Often lower than the limit, sometimes zero.

California public health goal
0.1 ppb

California OEHHA PHG (1999) For comparison the legal limit is 2 ppb.

Health effects the EPA associates with it: Hair loss; changes in blood; kidney, intestine, or liver problems.

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.

Where in Florida

Highest reported levels

Showing the 25 highest of 38 systems that reported Thallium.

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Data Sources

EPA SDWISSystem identity, population, countyret. 2026
FDEPFlorida drinking-water chemical monitoringret. 2026
CCREach utility’s own annual reportret. 2026

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.