PlainWater

Dewey County, South Dakota

SDWIS compliance plate

Sheet SD041 · Dewey County 5 sys · 874 viol · #2617/3254

VIOL-SEVERE · HEALTH-MID · RANK-BOTTOM · PHOTO-FINISH · PFAS-CLEAN · SRC-SW · SYS-TINY · BOOK-FULL

  • VIOL-SEVERE 100.0% flagged
  • HEALTH-MID 25.1% health
  • RANK-BOTTOM #2617/3254
  • PHOTO-FINISH ±0.0 pp
  • PFAS-CLEAN 0.0% detect
  • SRC-SW SW lead 60%
  • SYS-TINY 5 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Brown County (+ 0 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Dewey County ranks #2,617 of 3,254 counties by people served, and #26 of 65 counties in South Dakota. See methodology · corpus placement.

Dewey County standing, mid-flagged corpus third

Flagged-system rate 100.0% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 25.1% is health-based share above the upper 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 #2,617 of 3,254 · #26 of 65 in South Dakota.

Flagged-rate neighbourhood around Dewey County

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

0% 20% 40% 60% 80% 100% Shannon · lowest Buffalo · highest Lincoln · near Codington · near 50% 100% 100% 100% 100% 100% 100%

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

Water Systems

System Name Population Violations PFAS
Eagle Butte 4,000 64 Clean
Tri-County Rural Water System 2,190 172 Clean
Timber Lake 499 207 -
T C & G Rural Water System 166 132 -
Isabel 145 299 -

Compare beyond South Dakota

Mid-flagged peers for Dewey County

Cross-state counties nearest Dewey County on flagged-system share (100.0%) and cumulative violation count (874). 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.