New Castle County tap water: hardness, PFAS and lead
New Castle County, Delaware has about 588,093 residents (Census 2024 estimate) and 31 community water systems in EPA records. The largest local system is Artesian Water Company, serving about 231,114 people from surface water.
✓ 0 of 6 largest systems with health-based violationsPFAS detected at 5 of 6 sampled systemsHardness 5.8 gpg (low confidence)
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
How hard is New Castle County water?
Artesian Water CompanyEstimate: untreated local water, not your tap · Low confidence
5.8 gpg(100 mg/L), moderately hard
New Castle County: median of 12,724 results from 546 monitoring sites (streams and wells). Utilities may blend or treat water, so your tap can differ.
County estimates: Hard Water Map (hardwatermap.com), CC BY 4.0, derived from the USGS/EPA Water Quality Portal; file generated 2026-07-22. License
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
Softener size at 5.8 gpg
For a 3-person home using 57 gallons per person per day and regenerating weekly, you'd remove about 6,943 grains between regenerations. Suggested size: 24,000 grain. This uses a low-confidence county estimate, so confirm with a test first.
Estimate only. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
The 6 biggest of 31 community water systems on EPA records for this county. Service areas don't follow county lines; your water bill names your provider.
Artesian Water Company
DE0000552 · serves about 231,114 people · Surface water
✓ No health-based violations✓ Lead below action levelPFAS detected (8 types)
Lead 90th percentile: 1 ppb (period starting 2024-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
PFPeA: highest sample 106 ppt (18 of 45 samples); no federal limit
PFBA: highest sample 79.1 ppt (21 of 45 samples); no federal limit
PFHxA: highest sample 72.2 ppt (14 of 45 samples); no federal limit
PFOA: highest sample 23.1 ppt (8 of 45 samples); federal limit 4.0 ppt as a running annual average
PFHpA: highest sample 18.9 ppt (5 of 45 samples); no federal limit
PFHxS: highest sample 8.9 ppt (3 of 45 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
PFBS: highest sample 8.7 ppt (5 of 45 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
PFOS: highest sample 6 ppt (2 of 45 samples); federal limit 4.0 ppt as a running annual average
DE0000663 · serves about 107,976 people · Surface water
✓ No health-based violations✓ Lead below detectionPFAS detected (6 types)
Lead 90th percentile: <DL (below the lab detection/reporting limit; reported as 0) (period starting 2021-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
PFPeA: highest sample 32.2 ppt (8 of 8 samples); no federal limit
PFHxA: highest sample 21.1 ppt (8 of 8 samples); no federal limit
PFBA: highest sample 14.1 ppt (7 of 8 samples); no federal limit
PFOA: highest sample 9.9 ppt (8 of 8 samples); federal limit 4.0 ppt as a running annual average
PFHpA: highest sample 8.4 ppt (5 of 8 samples); no federal limit
PFBS: highest sample 3.6 ppt (4 of 8 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
DE0000564 · serves about 100,495 people · Surface water
✓ No health-based violations✓ Lead below action levelPFAS detected (9 types)
Lead 90th percentile: 2 ppb (period starting 2021-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
PFBA: highest sample 40.6 ppt (8 of 8 samples); no federal limit
PFPeA: highest sample 32.1 ppt (8 of 8 samples); no federal limit
PFHxA: highest sample 31.7 ppt (8 of 8 samples); no federal limit
PFHpA: highest sample 27.7 ppt (8 of 8 samples); no federal limit
PFOA: highest sample 24.4 ppt (8 of 8 samples); federal limit 4.0 ppt as a running annual average
PFNA: highest sample 11.6 ppt (8 of 8 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
PFDA: highest sample 4.7 ppt (3 of 8 samples); no federal limit
PFUnA: highest sample 3.8 ppt (2 of 8 samples); no federal limit
PFBS: highest sample 3.7 ppt (6 of 8 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
DE0000630 · serves about 40,000 people · Surface water
✓ No health-based violations✓ Lead below action levelPFAS detected (8 types)
Lead 90th percentile: 1 ppb (period starting 2022-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
PFOA: highest sample 25.3 ppt (5 of 6 samples); federal limit 4.0 ppt as a running annual average
PFHxA: highest sample 13.2 ppt (6 of 6 samples); no federal limit
PFPeA: highest sample 12.6 ppt (5 of 6 samples); no federal limit
PFBA: highest sample 11.2 ppt (2 of 6 samples); no federal limit
PFHpA: highest sample 7.9 ppt (2 of 6 samples); no federal limit
PFOS: highest sample 7.5 ppt (2 of 6 samples); federal limit 4.0 ppt as a running annual average
PFBS: highest sample 6.6 ppt (2 of 6 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
PFHxS: highest sample 5.5 ppt (2 of 6 samples); federal limit 10.0 ppt as a running annual average, also counted in EPA's PFAS mixture (hazard index) limit (currently in effect; EPA has proposed removing it)
DE0000614 · serves about 17,700 people · Surface water
✓ No health-based violations✓ Lead below detection✓ No PFAS detected
Lead 90th percentile: <DL (below the lab detection/reporting limit; reported as 0) (period starting 2025-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
DE0000634 · serves about 5,549 people · Groundwater
✓ No health-based violations✓ Lead below detectionPFAS detected (2 types)
Lead 90th percentile: <DL (below the lab detection/reporting limit; reported as 0) (period starting 2023-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
PFBA: highest sample 147.2 ppt (1 of 2 samples); no federal limit
PFPeA: highest sample 122.9 ppt (1 of 2 samples); no federal limit
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
A PFAS detection is not a violation. Federal limits (4 ppt for PFOA and PFOS) apply to running annual averages, with compliance required by 2029. In May 2026 EPA proposed extending the PFOA/PFOS deadline to 2031 and removing other PFAS limits; not final as of 2026-10-21.
Test your own tap
These are public records for whole systems. Your home's pipes, fixtures and any private well can change what you drink. A certified lab test or a hardness test strip gives you your own numbers. Then use our PFAS and lead filter selector to see which certifications to look for.
Common questions about New Castle County water
Is tap water in New Castle County safe to drink?
None of the 6 largest systems here have a health-based violation in EPA records since October 2021. Artesian Water Company's most recent lead 90th percentile was 1 ppb (2024), below the 15 ppb action level. Public records can't guarantee what comes out of your tap, especially with older plumbing, so a home test is the surest check.
How hard is the water in New Castle County?
There's no published utility figure in our data, but untreated local stream and well samples in New Castle County have a median of about 5.8 grains per gallon (100 mg/L, moderately hard). That's a low-confidence estimate of source water, not your tap, so test before you buy equipment. For a 3-person home at 5.8 gpg, our softener calculator suggests a 24,000 grain unit as a starting point.
Is there PFAS in New Castle County water?
5 of the 6 sampled systems listed here detected at least one PFAS in EPA's UCMR 5 testing, and 7 results were above the level of a federal limit in at least one sample. A detection isn't a violation: federal PFAS limits apply to running annual averages starting in 2029.
Which water system serves my address in New Castle County?
Most homes are served by Artesian Water Company or one of the other systems listed on this page, but service areas don't follow county lines. Your water bill names your provider, and its annual Consumer Confidence Report has the full test results.
Data as of October 21, 2026. Figures are copied from public records and combined with our own calculations; they can be out of date or wrong. Tapped Out isn't affiliated with any utility or the EPA. Written and reviewed by the Tapped Out team. How we calculate · All sources.