1-Butanol is a solvent used in consumer products and industry, and EPA classes it that way. EPA monitored it nationwide in 2018 to 2020 and has set no limit for it.
In Florida, 1-Butanol was found in 7 community water systems serving about 980,490 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: Industrial discharge; solvents, paints and coatings; some natural fermentation.
Enforceable. A utility must stay at or under this.
Health-based, not enforceable. Often lower than the limit, sometimes zero.
EPA Reference Concentration (UCMR 4), Contaminant Information Sheets for the Final CCL 4. 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 700 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.
Activated carbon adsorbs it, and it is volatile enough that aeration 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.
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.