PlainWater

Ontonagon County, Michigan

SDWIS compliance plate

Sheet MI131 · Ontonagon County 26 sys · 768 viol · #2757/3254

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

  • VIOL-SEVERE 96.2% flagged
  • HEALTH-LOW 17.3% health
  • RANK-BOTTOM #2757/3254
  • PHOTO-FINISH ±0.2 pp
  • PFAS-CLEAN 0.0% detect
  • SRC-GW GW lead 96%
  • SYS-SMALL 26 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Monroe County (+ 0.2 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Ontonagon County ranks #2,757 of 3,254 counties by people served, and #82 of 83 counties in Michigan. See methodology · corpus placement.

Ontonagon County standing, mid-flagged corpus third

Flagged-system rate 96.2% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 17.3% is health-based share in the middle third (≤ 24.5%) . UCMR5 detect rate 0.0% is UCMR5 detect rate at or below the tested-pool lower third (≤ 0.0%) . Population served ranks #2,757 of 3,254 · #82 of 83 in Michigan.

Flagged-rate neighbourhood around Ontonagon County

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

0% 20% 40% 60% 80% 100% Oscoda · lowest Genesee · near Ontonagon · this county Menominee · highest 52.9% 95.7% 95.7% 95.8% 96.2% 96.3% 100%

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

Water Systems

Compare beyond Michigan

Mid-flagged peers for Ontonagon County

Cross-state counties nearest Ontonagon County on flagged-system share (96.2%) and cumulative violation count (768). 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.