Somerset County tap water: hardness, PFAS and lead

Somerset County, New Jersey has about 357,467 residents (Census 2024 estimate) and 5 community water systems in EPA records. The largest local system is Franklin Township Dept of Public Works, serving about 57,150 people from surface water.

! 1 of 5 largest systems with health-based violationsPFAS detected at 3 of 3 sampled systemsHardness 4.5 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 Somerset County water?

Franklin Township Dept of Public Works Estimate: untreated local water, not your tap · Low confidence

4.5 gpg (78 mg/L), moderately hard

Somerset County: median of 2,841 results from 115 monitoring sites (streams and wells). Utilities may blend or treat water, so your tap can differ.

Source: Hard Water Map county data, samples through 2023

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 4.5 gpg

For a 3-person home using 57 gallons per person per day and regenerating weekly, you'd remove about 5,387 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.

Open the softener calculator with 4.5 gpg

Largest water systems in Somerset County

The 5 biggest of 5 community water systems on EPA records for this county. Service areas don't follow county lines; your water bill names your provider.

Franklin Township Dept of Public Works

NJ1808001 · serves about 57,150 people · Surface water

✓ No health-based violations✓ Lead below action levelPFAS detected (4 types)

Lead 90th percentile: 2.3 ppb (period starting 2026-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).

  • PFOA: highest sample 9 ppt (12 of 12 samples); federal limit 4.0 ppt as a running annual average
  • PFBA: highest sample 6.1 ppt (1 of 12 samples); no federal limit
  • PFPeA: highest sample 4.5 ppt (8 of 12 samples); no federal limit
  • PFHxA: highest sample 3.8 ppt (5 of 12 samples); no federal limit

EPA ECHO record

Nj American Water - Short Hills

NJ0712001 · serves about 217,230 people · Surface water

✓ No health-based violations✓ Lead below action levelPFAS detected (7 types)

Lead 90th percentile: 3 ppb (period starting 2026-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).

  • PFPeA: highest sample 27.5 ppt (10 of 30 samples); no federal limit
  • PFHxA: highest sample 11.2 ppt (7 of 30 samples); no federal limit
  • PFOA: highest sample 9.1 ppt (16 of 30 samples); federal limit 4.0 ppt as a running annual average
  • PFBA: highest sample 6.5 ppt (4 of 30 samples); no federal limit
  • PFOS: highest sample 6.1 ppt (3 of 30 samples); federal limit 4.0 ppt as a running annual average
  • PFHxS: highest sample 3.6 ppt (2 of 30 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 3.1 ppt (2 of 30 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit

EPA ECHO record

South Brunswick Twp W Di

NJ1221004 · serves about 45,450 people · Surface water

! 1 health-based violation✓ Lead below detectionPFAS detected (6 types)

Lead 90th percentile: <DL (below the lab detection/reporting limit; reported as 0) (period starting 2026-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).

  • PFOA: highest sample 23 ppt (6 of 9 samples); federal limit 4.0 ppt as a running annual average
  • PFBA: highest sample 13 ppt (4 of 9 samples); no federal limit
  • PFPeA: highest sample 9.5 ppt (5 of 9 samples); no federal limit
  • PFHxA: highest sample 8.8 ppt (5 of 9 samples); no federal limit
  • PFHpA: highest sample 6.9 ppt (4 of 9 samples); no federal limit
  • PFBS: highest sample 3.8 ppt (2 of 9 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit

EPA ECHO record

Rocky Hill W Dept

NJ1817001 · serves about 687 people · Groundwater

✓ No health-based violations✓ Lead below action levelPFAS: not sampled

Lead 90th percentile: 2.3 ppb (period starting 2022-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).

EPA ECHO record

Nj American Water - Twin Lakes

NJ1803002 · serves about 250 people · Groundwater

✓ No health-based violations✓ Lead below detectionPFAS: not sampled

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).

EPA ECHO record

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 Somerset County water

Is tap water in Somerset County safe to drink?

1 of the 5 largest systems here have at least one health-based violation in EPA records since October 2021 (see each system below for status). Franklin Township Dept of Public Works's most recent lead 90th percentile was 2.3 ppb (2026), 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 Somerset County?

There's no published utility figure in our data, but untreated local stream and well samples in Somerset County have a median of about 4.5 grains per gallon (78 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 4.5 gpg, our softener calculator suggests a 24,000 grain unit as a starting point.

Is there PFAS in Somerset County water?

3 of the 3 sampled systems listed here detected at least one PFAS in EPA's UCMR 5 testing, and 4 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 Somerset County?

Most homes are served by Franklin Township Dept of Public Works 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.

More New Jersey counties

Sources for this page

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.