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Drinking water / Delaware

Artesian Water Company

PWSID DE0000552

PFAS was measured above a final federal limit in this system.

The highest result was PFPeA at 106 ng/L, against a federal limit of - ng/L. A system over the limit has a legal obligation to act by 2031; it does not mean the water is unsafe to drink today, and it does not describe what reaches one specific tap.

231,114

people served

85,347

service connections

purchased surface water

primary source

1,355

sample results

Every compound detected

Highest single result per compound, in nanograms per litre (the same unit as parts per trillion). EPA proposed in May 2026 to rescind the limits marked as withdrawn, so those results are reported without a comparison.

CompoundHighest resultFederal limitReading
PFPeA106 ng/Lnonebelow limit
PFBA79.1 ng/Lnonebelow limit
PFHxA72.2 ng/Lnonebelow limit
PFOA23.1 ng/L4 ng/Labove limit
PFHpA18.9 ng/Lnonebelow limit
PFHxS8.9 ng/Lwithdrawnno current limit
PFBS8.7 ng/Lnonebelow limit
PFOS6 ng/L4 ng/Labove limit

Counties served

What this does not tell you

These are entry-point results for the system, not one tap. Water mixes between sources, sits in mains and passes through household plumbing. A certified lab test of your own tap is the only thing that answers what you drink, and it is the only route at all for a private well.

How to test your tap water

If you want to treat it

Reverse osmosis and properly specified activated carbon remove most PFAS at the tap. Certification to NSF/ANSI 53 or 58 with an explicit PFOA and PFOS claim is what separates a PFAS filter from a taste filter.

Which filters actually work

Source: EPA Fifth Unregulated Contaminant Monitoring Rule occurrence data, with system detail from EPA SDWIS. Umwelt reports these results as published. Methodology and sources