Water Quality in Rapid City, SD: No Violations — Grade B
Grade B · Score 77/100 · 5 water systems · Updated 2026-05-03
Rapid City's water is mostly safe. Minor violations exist but are primarily monitoring-related.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Federal compliance data for Rapid City, SD: no violations across 5 monitored systems.
Water Quality by ZIP Code in Rapid City
Water quality varies across Rapid City's 4 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 57701 | B | 76 | 0 | 0 | View report → |
| 57702 | B | 76 | 0 | 0 | View report → |
| 57703 | B | 76 | 0 | 0 | View report → |
| 57709 | B | 80 | 0 | 0 | View report → |
Water Quality Overview
Rapid City, South Dakota receives a water quality grade of B with an overall score of 77 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
No EPA violations have been recorded for the 5 water systems serving Rapid City. This is a positive indicator, though it does not guarantee the absence of all contaminants — some substances (like PFAS) are not yet fully regulated.
What Grade B Means
A grade of B indicates good compliance with EPA drinking water standards. While not perfect, Rapid City's water systems meet the vast majority of federal requirements. Minor violations may exist but typically relate to monitoring or reporting rather than health-based standards.
Lead Levels
The average 90th percentile lead level across Rapid City water systems is 0.0060 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 53% of homes built before 1986, Rapid City has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Rapid City is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Rapid City
Rapid City is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 86,567 people across 4 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
How to Check Your Water in Rapid City
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Rapid City vs. Nearby South Dakota Cities
How Rapid City's water quality compares to similar cities in South Dakota:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Rapid City | B | 0 | 5 | 86,567 |
| Aberdeen | C | 16 | 5 | 50,402 |
| Columbia | D | 0 | 1 | 27,989 |
| Watertown | C | 1 | 2 | 27,242 |
Water Quality by ZIP Code in Rapid City
Water quality varies across Rapid City's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
| ZIP Code | Score | Grade | Violations | Health-Based |
|---|---|---|---|---|
| 57701 | 76 | B | 0 | 0 |
| 57702 | 76 | B | 0 | 0 |
| 57703 | 76 | B | 0 | 0 |
| 57709 | 80 | B | 0 | 0 |
Common Questions About Rapid City Water
These are the most common questions residents search for about water quality in Rapid City, South Dakota:
Is Rapid City water hard or soft? Water hardness varies by source. Rapid City's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Rapid City tap water? Rapid City's water receives a grade of B (77/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Rapid City? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Rapid City vs. South Dakota Average
Understanding how Rapid City compares to the broader South Dakota average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Rapid City.
ZIP Codes in Rapid City
Rapid City spans 4 ZIP codes. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.
Frequently Asked Questions
Your Water is Safe — Here's How to Keep It That Way
Grade B is excellent news. Here's what proactive homeowners do to maintain water quality:
Annual Water Testing
EPA recommends annual testing even with clean water. Home test kits: $20-$50. Catches changes before they become problems.
Maintenance Filtration
A basic carbon filter removes chlorine taste and catches emerging contaminants like PFAS that aren't yet fully regulated.
Plumbing Check
Even safe city water picks up lead from home pipes. If your home was built before 1986, a one-time pipe inspection is recommended.