Dichloromethane
Overview
Also called methylene chloride, a solvent used in paint stripping and manufacturing.
In Florida, Dichloromethane was found in 20 community water systems serving about 119,329 people. 1 of those readings was above the federal legal limit, together serving 268 people.
The highest reading relative to the limit was at Florida Heights S/D in Marion County, at 124% of it.
Where it comes from: Discharge from pharmaceutical and chemical factories.
The standards
Enforceable. A utility must stay at or under this.
Health-based, not enforceable. Often lower than the limit, sometimes zero.
California OEHHA PHG (2000).
Health effects the EPA associates with it: Liver problems and increased cancer risk.
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
Dichloromethane is adsorbed poorly by activated carbon relative to other solvents, so a standard carbon filter is not a reliable answer on its own. Aeration is the more effective method for 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.
Where in Florida
Highest reported levels
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.