PlainWater

Union County, South Dakota

SDWIS compliance plate

Sheet SD127 · Union County 8 sys · 604 viol · #2075/3254

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

  • VIOL-SEVERE 100.0% flagged
  • HEALTH-LOW 2.6% health
  • RANK-LOWER #2075/3254
  • PHOTO-FINISH ±0.0 pp
  • PFAS-NONE No UCMR5 set
  • SRC-GW GW lead 88%
  • SYS-TINY 8 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, Union County ranks #2,075 of 3,254 counties by people served, and #16 of 65 counties in South Dakota. See methodology · corpus placement.

Union 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 2.6% is health-based share at or below the lower third (≤ 10.3%) . No UCMR5 tests in this extract for Union County . Population served ranks #2,075 of 3,254 · #16 of 65 in South Dakota.

Flagged-rate neighbourhood around Union County

Lowest/highest poles plus in-state counties nearest Union 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
Dakota Dunes Cid 3,700 3 -
North Sioux City 3,042 69 -
Beresford 2,359 2 -
Elk Point 2,124 87 -
Clay RWS/South Union 1,447 331 -
Alcester 820 30 -
Jefferson 475 79 -
Two Rivers Golf Club 120 3 -

Compare beyond South Dakota

Mid-flagged peers for Union County

Cross-state counties nearest Union County on flagged-system share (100.0%) and cumulative violation count (604). 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.