Weld County tap water: hardness, PFAS and lead

Weld County, Colorado has about 369,745 residents (Census 2024 estimate) and 58 community water systems in EPA records. The largest local system is Greeley City of, serving about 132,310 people from surface water.

✓ 0 of 6 largest systems with health-based violationsPFAS detected at 0 of 6 sampled systemsHardness 32.1 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 Weld County water?

Greeley City of Estimate: untreated local water, not your tap · Low confidence

32.1 gpg (550 mg/L), very hard

Weld County: median of 8,275 results from 682 monitoring sites (streams and wells). Utilities may blend or treat water, so your tap can differ.

Source: Hard Water Map county data, samples through 2026

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 32.1 gpg

For a 3-person home using 57 gallons per person per day and regenerating weekly, you'd remove about 38,424 grains between regenerations. Suggested size: 40,000 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 32.1 gpg

Largest water systems in Weld County

The 6 biggest of 58 community water systems on EPA records for this county. Service areas don't follow county lines; your water bill names your provider.

Greeley City of

CO0162321 · serves about 132,310 people · Surface water

✓ No health-based violations✓ Lead below action level✓ No PFAS detected

Lead 90th percentile: 4 ppb (period starting 2025-07-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).

EPA ECHO record

Firestone Town of

CO0162476 · serves about 27,798 people · Surface water

✓ No health-based violations✓ Lead below action level✓ No PFAS detected

Lead 90th percentile: 3.6 ppb (period starting 2024-07-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).

EPA ECHO record

Johnstown Town of

CO0162418 · serves about 27,295 people · Surface water

✓ No health-based violations✓ Lead below action level✓ No PFAS detected

Lead 90th percentile: 1 ppb (period starting 2025-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).

EPA ECHO record

Windsor Town of

CO0162843 · serves about 23,500 people · Surface water

✓ No health-based violations✓ Lead below action level✓ No PFAS detected

Lead 90th percentile: 5.8 ppb (period starting 2023-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).

EPA ECHO record

Evans City of

CO0162260 · serves about 19,369 people · Surface water

✓ No health-based violations✓ Lead below action level✓ No PFAS detected

Lead 90th percentile: 2.4 ppb (period starting 2026-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).

EPA ECHO record

Frederick Town of

CO0162288 · serves about 17,173 people · Surface water

✓ No health-based violations✓ Lead below action level✓ No PFAS detected

Lead 90th percentile: 2.9 ppb (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 Weld County water

Is tap water in Weld County safe to drink?

None of the 6 largest systems here have a health-based violation in EPA records since October 2021. Greeley City of's most recent lead 90th percentile was 4 ppb (2025), 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 Weld County?

There's no published utility figure in our data, but untreated local stream and well samples in Weld County have a median of about 32.1 grains per gallon (550 mg/L, very 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 32.1 gpg, our softener calculator suggests a 40,000 grain unit as a starting point.

Is there PFAS in Weld County water?

None of the 6 sampled systems listed here detected PFAS above EPA's reporting levels in UCMR 5 testing.

Which water system serves my address in Weld County?

Most homes are served by Greeley City of 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 Colorado 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.