Franklin County tap water: hardness, PFAS and lead
Franklin County, Ohio has about 1,356,303 residents (Census 2024 estimate) and 31 community water systems in EPA records. The largest local system is Columbus Public Water System, serving about 1,309,468 people from surface water.
✓ 0 of 6 largest systems with health-based violationsPFAS detected at 4 of 6 sampled systemsHardness 7.0 gpg (medium 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 Franklin County water?
Columbus Public Water SystemMeasured (utility report, page read 2026-10-21) · Medium confidenceUnverified source
7.0 gpg(120 mg/L), moderately hard
Columbus softens its water to an average of about 120 ppm. The city page now returns 403 to automated checks, so this source could not be re-verified.
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 7 gpg
For a 3-person home using 57 gallons per person per day and regenerating weekly, you'd remove about 8,379 grains between regenerations. Suggested size: 24,000 grain.
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.
Columbus Public Water System
OH2504412 · serves about 1,309,468 people · Surface water
✓ No health-based violations✓ Lead below action levelPFAS detected (6 types)
Lead 90th percentile: 1.2 ppb (period starting 2021-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
PFHxA: highest sample 18.2 ppt (3 of 10 samples); no federal limit
PFBA: highest sample 17 ppt (4 of 10 samples); no federal limit
PFPeA: highest sample 14.2 ppt (3 of 10 samples); no federal limit
PFBS: highest sample 11.1 ppt (1 of 10 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
PFOA: highest sample 5.3 ppt (1 of 10 samples); federal limit 4.0 ppt as a running annual average
PFHpA: highest sample 4.3 ppt (1 of 10 samples); no federal limit
OH2500103 · serves about 14,250 people · Surface water
✓ No health-based violations✓ Lead below detectionPFAS detected (5 types)
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).
PFHxA: highest sample 12.2 ppt (3 of 8 samples); no federal limit
PFBA: highest sample 11.7 ppt (5 of 8 samples); no federal limit
PFPeA: highest sample 11.4 ppt (3 of 8 samples); no federal limit
PFBS: highest sample 8.3 ppt (2 of 8 samples); no individual limit; counted in EPA's PFAS mixture (hazard index) limit
PFOA: highest sample 5.6 ppt (2 of 8 samples); federal limit 4.0 ppt as a running annual average
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 Franklin County water
Is tap water in Franklin County safe to drink?
None of the 6 largest systems here have a health-based violation in EPA records since October 2021. Columbus Public Water System's most recent lead 90th percentile was 1.2 ppb (2021), 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 Franklin County?
Columbus Public Water System reports about 7.0 grains per gallon (120 mg/L), which is moderately hard. For a 3-person home at 7 gpg, our softener calculator suggests a 24,000 grain unit as a starting point.
Is there PFAS in Franklin County water?
4 of the 6 sampled systems listed here detected at least one PFAS in EPA's UCMR 5 testing, and 2 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 Franklin County?
Most homes are served by Columbus Public Water System 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.