PlainWater

Hamilton County, Ohio

SDWIS compliance plate

Sheet OH061 · Hamilton County 28 sys · 1,480 viol · #73/3254

VIOL-SEVERE · HEALTH-LOW · RANK-TOP · PHOTO-FINISH · PFAS-MID · SRC-GW · SYS-SMALL · BOOK-FULL

  • VIOL-SEVERE 82.1% flagged
  • HEALTH-LOW 9.5% health
  • RANK-TOP #73/3254
  • PHOTO-FINISH ±0.3 pp
  • PFAS-MID 44.4% detect
  • SRC-GW GW lead 68%
  • SYS-SMALL 28 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Butler County ( -0.3 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Hamilton County ranks #73 of 3,254 counties by people served, and #3 of 88 counties in Ohio. See methodology · corpus placement.

Hamilton County standing, lower-flagged corpus third

Flagged-system rate 82.1% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 9.5% is health-based share at or below the lower third (≤ 10.3%) . UCMR5 detect rate 44.4% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #73 of 3,254 · #3 of 88 in Ohio.

Flagged-rate neighbourhood around Hamilton County

Lowest/highest poles plus in-state counties nearest Hamilton County on % of SDWIS systems with ≥1 violation. Full ladder: /counties.

0% 20% 40% 60% 80% 100% Fayette · lowest Marion · near Paulding · near Vinton · highest 78.6% 81.8% 81.8% 82.1% 82.8% 83.3% 100%

Source: EPA SDWIS (county aggregates) As of 2026-05-15

Water Systems

Compare beyond Ohio

Lower-flagged peers for Hamilton County

Cross-state counties nearest Hamilton County on flagged-system share (82.1%) and cumulative violation count (1,480). In-state neighbours stay on the compliance plate above.

Similar flagged-system rate

Nearest cross-state counties by % of SDWIS systems with at least one violation on record.

4 peers

Similar violation load

Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).

4 peers
Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.