PlainWater

Clark County, South Dakota

SDWIS compliance plate

Sheet SD025 · Clark County 7 sys · 919 viol · #2886/3254

VIOL-SEVERE · HEALTH-LOW · RANK-BOTTOM · PHOTO-FINISH · PFAS-NONE · SRC-GW · SYS-TINY · BOOK-MOST

  • VIOL-SEVERE 100.0% flagged
  • HEALTH-LOW 15.6% health
  • RANK-BOTTOM #2886/3254
  • PHOTO-FINISH ±0.0 pp
  • PFAS-NONE No UCMR5 set
  • SRC-GW GW lead 100%
  • SYS-TINY 7 systems
  • BOOK-MOST 6/7 fields

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

According to EPA SDWIS county population served used on /counties, Clark County ranks #2,886 of 3,254 counties by people served, and #34 of 65 counties in South Dakota. See methodology · corpus placement.

Clark 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 15.6% is health-based share in the middle third (≤ 24.5%) . No UCMR5 tests in this extract for Clark County . Population served ranks #2,886 of 3,254 · #34 of 65 in South Dakota.

Flagged-rate neighbourhood around Clark County

Lowest/highest poles plus in-state counties nearest Clark 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
Clark Rural Water System 2,325 68 -
Clark 1,148 20 -
Willow Lake 255 59 -
Fordham Colony 142 178 -
Collins Colony 95 106 -
Shamrock Colony 75 231 -
Garden City 33 257 -

Compare beyond South Dakota

Mid-flagged peers for Clark County

Cross-state counties nearest Clark County on flagged-system share (100.0%) and cumulative violation count (919). 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.