RAPID VALLEY SANITARY DISTRICT

RAPID CITY, SD · ~11,408 people served

Check your exact address → RAPID CITY overview

Good

PurityRadar safety score

PWSID

SD4600274

State

South Dakota

City

RAPID CITY

Population served

11,408

Primary source

Surface water

Score history

▼ 19 points — the score moved from 100 to 81 on Jun 18, 2026, as newly published EPA data was incorporated.

Jun 18, 2026 · score 100 Jun 18, 2026 · score 81

2 score updates logged since tracking began Jun 18, 2026. Each future EPA re-score adds a point.

PFAS & contaminant readings

Latest detections from EPA’s UCMR5 monitoring (through Dec 2024). Levels in parts per trillion (ppt).

PFOS

Perfluorooctanesulfonic acid

5.7 ppt

limit 4 ppt

Above EPA limit · 1.4×

PFHxS

Perfluorohexanesulfonic acid

3.3 ppt

limit 10 ppt

Below EPA limit

Lithium

14,000 ppt

limit —

No federal limit

Violations & enforcement

Violations on record

Unaddressed

Health-based

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Jun 2008. Official EPA record →

Max contaminant level (MCL) · Total coliform health-based began Nov 2007 Resolved

Treatment technique · EPA contaminant 2265 health-based began Jan 1995 Resolved

Treatment technique · EPA contaminant 2257 health-based began Jan 1995 Resolved

Monitoring & reporting · Gross alpha began Aug 1988 Resolved

Monitoring & reporting · Uranium began Aug 1988 Resolved

Recent enforcement actions

State action · SOX Jun 2008
State action · SIF Dec 2007
State action · SIE Dec 2007
State action · SOX Apr 1997
State action · SIE Apr 1996
State action · SOX Jan 1993
State action · SIA Jan 1993
State action · SIE Sep 1989

This profile is built from EPA public records for system SD4600274 — SDWIS violations and UCMR5 PFAS sampling. The score is system-level and can’t account for your home’s plumbing (older pipes can add lead at the tap). For health decisions, check your exact address, read the utility’s Consumer Confidence Report, and confirm with your provider.