Rapid City
SD

Is Rapid City, SD Tap Water Safe to Drink?

Rapid City tap water meets federal Safe Drinking Water Act standards but 3 of 3 ZIP codes show detections above EPA health guidelines, primarily for lithium. A certified filter is recommended for households that want an additional layer of protection.

4Water systems
3ZIP codes
100%ZIPs above EPA guideline
Metro areaRapid City, SD
Latest data2025-09-03

Where Does Rapid City Get Its Water?

Water in Rapid City, SD is provided by 4 public water systems: RAPID CITY, BLACK HAWK WATER USER DISTRICT, BOX ELDER and RAPID VALLEY SANITARY DISTRICT.

How Is Rapid City Tap Water Treated?

Treated water is disinfected using chloramines and free chlorine. Treatment includes conventional treatment (coagulation, flocculation, and filtration), groundwater disinfection, membrane filtration and post-ozone biofiltration.

What's in Rapid City Tap Water?

The following contaminants were detected most frequently in Rapid City public water systems. 3 of 3 ZIP codes showed detections above EPA health guidelines.

ContaminantPeak detectedEPA guidelineZIPs detectedStatus
lithium 13 µg/L 10 µg/L 2 ZIPs Above guideline
PFHxS 0.0056 µg/L 0.004 µg/L 2 ZIPs Above guideline
PFTrDA 0.007 µg/L — 0 ZIPs Within guideline
PFOS 0.0057 µg/L — 1 ZIP Within guideline
PFBA 0.005 µg/L — 0 ZIPs Within guideline

Health Risk Profile for Rapid City

Based on EPA monitoring data, 3 of 3 ZIP codes in Rapid City have recorded detections above EPA health guidelines. Sensitive populations such as infants, pregnant individuals, and those with weakened immune systems may benefit from an additional layer of protection such as a certified point-of-use filter.

Best Broad-Spectrum Filters for This Water Profile

This city profile includes PFAS detections, chlorine disinfection, and other dissolved contaminants. Reverse osmosis (RO) systems certified under NSF/ANSI 58 provide broad reduction coverage; for PFAS specifically, confirm NSF/ANSI P473 or equivalent PFAS reduction certification.

Waterdrop G3P600 Reverse Osmosis System
Under-sink RO system

8-stage tankless RO system certified to NSF/ANSI 58, reduces 1,000+ contaminants including PFAS, lead, arsenic, fluoride, and nitrates.

See recommendations matched to your exact address: choose your ZIP code below.

Frequently Asked Questions about Rapid City Tap Water

Is Rapid City tap water safe to drink?

Rapid City tap water meets Safe Drinking Water Act requirements but 3 of 3 ZIP codes show contaminant levels above EPA health-based guidelines. A certified point-of-use filter adds an extra layer of protection.

What contaminants are in Rapid City tap water?

The most commonly detected contaminants in Rapid City water systems include: lithium, PFHxS, PFTrDA. See the ZIP-level reports for exact measurements and EPA guideline comparisons.

Where does Rapid City get its drinking water?

Rapid City receives water from 4 public water systems, including RAPID CITY.

Do I need a water filter in Rapid City?

If your ZIP code is among those with detections above EPA health guidelines, choose a filter certified for the specific contaminants shown in your ZIP report. Reverse osmosis is generally the broadest option for PFAS, lithium, and many other dissolved contaminants.

How often is Rapid City tap water tested?

Public water systems in Rapid City are required by the EPA to test for regulated contaminants on schedules ranging from daily (for microbials and disinfectants) to annual or triennial (for many chemical contaminants). Results are published in annual Consumer Confidence Reports (CCRs). The data on this page reflects the most recent available EPA monitoring results, with the latest sample date of 2025-09-03.

Tap water reports by ZIP in Rapid City

Water utilities serving Rapid City, SD

Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.

Modeled boundaries are shown with a dashed outline. Outlines appear when service-area boundary data is available for this ZIP.

Also covers / overlaps with