PlainWater

St. John the Baptist Parish, Louisiana

SDWIS compliance plate

Sheet LA095 · St. John the Baptist Parish 12 sys · 1,210 viol · #981/3254

VIOL-SEVERE · HEALTH-HIGH · RANK-UPPER · PHOTO-FINISH · PFAS-HIGH · SRC-GW · SYS-SMALL · BOOK-FULL

  • VIOL-SEVERE 91.7% flagged
  • HEALTH-HIGH 70.2% health
  • RANK-UPPER #981/3254
  • PHOTO-FINISH ±0.0 pp
  • PFAS-HIGH 66.7% detect
  • SRC-GW GW lead 75%
  • SYS-SMALL 12 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Vermilion Parish (+ 0 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, St. John the Baptist Parish ranks #981 of 3,254 counties by people served, and #27 of 64 counties in Louisiana. See methodology · corpus placement.

St. John the Baptist Parish standing, lower-flagged corpus third

Flagged-system rate 91.7% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 70.2% is health-based share above the upper third (> 24.5%) . UCMR5 detect rate 66.7% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #981 of 3,254 · #27 of 64 in Louisiana.

Flagged-rate neighbourhood around St. John the Baptist Parish

Lowest/highest poles plus in-state counties nearest St. John the Baptist Parish on % of SDWIS systems with ≥1 violation. Full ladder: /counties.

0% 20% 40% 60% 80% 100% St. Tammany Pa · lowest Vermilion Pari · near East Carroll P · highest 78.9% 91.4% 91.7% 91.7% 91.7% 91.7% 100%

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

Water Systems

Compare beyond Louisiana

Lower-flagged peers for St. John the Baptist Parish

Cross-state counties nearest St. John the Baptist Parish on flagged-system share (91.7%) and cumulative violation count (1,210). 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.