A widely used weed killer (herbicide) that can reach water as runoff.
In Florida, 2,4-D was found in 10 community water systems serving about 34,517 people. It was measured by 1,559 systems in all, so it was detected in under 1% of the systems that tested for it.
The highest reading relative to the limit was at Oak Hill Village MHP in Hillsborough County, at 7% of it.
Where it comes from: Runoff from herbicide used on row crops and lawns.
Enforceable. A utility must stay at or under this.
Health-based, not enforceable. Often lower than the limit, sometimes zero.
California OEHHA PHG (2009).
Health effects the EPA associates with it: Kidney, liver, or adrenal gland problems.
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.
Activated carbon is the standard treatment. A carbon block at the drinking tap covers ingestion; a whole-house carbon system covers bathing as well.
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.
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.