Is Rapid City, SD Tap Water Safe to Drink?
Graded C- — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
58.4/100
waterverge.com Rapid City, SD — Water Quality Report
Rapid City's drinking water received a grade of C- (58.4 out of 100), indicating poor water quality. The city's 4 water systems serve approximately 841 residents using groundwater.
Lead levels were measured at 1.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 392 violations on record, including 18 health-based violations. 23 remain unresolved.
What to know about Rapid City's water
Rapid City ranks #129 out of 141 cities in South Dakota for water quality, placing it among the lowest-rated in the state.
Rapid City relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, Rapid City may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Rapid City, SD water safe to drink?
Rapid City's drinking water has significant quality concerns based on EPA testing data. With a grade of C- (58.4/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 841 residents using groundwater (wells).
Recent water quality updates for Rapid City
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Rapid City's water quality assessment. Grade: C- (58.4/100).
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
Contaminants: Public Notice.
1 health-based. Contaminants: Nitrite.
Federal disaster declaration (FEMA DR-4463). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4440). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Rapid City's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Rapid City's water system has 392 total violations on record, including 18 health-based violations. 23 remain unresolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
Pennington County has experienced 7 federally declared disasters since 1965. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Spring Creek, Rapid Creek, Wild Irishman Gulch, Cleghorn Springs, South Canyon.
Where does Rapid City's water come from?
Rapid City's drinking water comes from groundwater (wells), supplied by 4 water systems serving approximately 841 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Spring Creek (river), Rapid Creek (river), Wild Irishman Gulch (river), Cleghorn Springs (river), South Canyon (river).
What Rapid City residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Rapid City's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Rapid City's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Rapid City
Industrial polluters nearby
Reported releases to surface water by facilities near Rapid City, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
FOREST PRODUCTS DISTRIBUTORS INC RAPID CITY, SD57703 | — | — | 2.9 mi |
HUBBARD FEEDS INC RAPID CITY, SD57701 | — | — | 0.9 mi |
PETE LIEN & SONS INC RAPID CITY, SD57702 | — | — | 5.5 mi |
GCC DACOTAH RAPID CITY, SD57702 | — | — | 2.8 mi |
U.S. DOD USAF, ELLSWORTH AFB ELLSWORTH AFB, SD57706 | — | — | 8.7 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Rapid City
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- ELLSWORTH AIR FORCE BASE8.3 mi
Source: EPA Superfund National Priorities List
Drought conditions
D3 — extreme droughtPennington County is currently in D3 (extreme drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Pennington County has experienced 7 federally declared disasters since 1965. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Rapid City's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 1.0 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.44 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.440 mg/L (1993)
EPA action level: 1.3 mg/L
See how Rapid City compares by contaminant
Explore where Rapid City ranks among all South Dakota cities for specific contaminants.
Water source & infrastructure
Where Rapid City's water comes from
Rapid City's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by private ownership and serves approximately 841 people through 4 water systems.
Water bodies near Rapid City
Rapid City is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Rapid City
| System Name | PWSID | Population | Source |
|---|---|---|---|
| PRAIRIE ACRES LLC | SD4600014 | 350 | GW |
| PRAIRIE ACRES NORTH | SD4600884 | 288 | GW |
| PRAIRIE ACRES SOUTH | SD4600428 | 170 | GW |
| GARDEN CITY | SD4600137 | 33 | GWP |
How Rapid City compares
Full South Dakota rankings →Rapid City's score of 58.4/100 is below the average of 66/100 among major South Dakota cities. It outscores 5 of 10 nearby cities.
Nearby cities
View South Dakota rankings →About Rapid City, SD
Wikipedia →Rapid City is a city in and the county seat of Pennington County, South Dakota, United States. It is located on the eastern slope of the Black Hills in western South Dakota and was named after Rapid Creek, where the settlement developed. It is the second-most populous city in the state with a population of 74,703 as of the 2020 census. The Rapid City metropolitan area has 156,000 residents.
Learn more about your water
Guides and resources related to Rapid City's water quality findings.
Explore water quality across Pennington
Frequently asked questions
Is Rapid City, SD tap water safe to drink?
Rapid City's water quality earned a grade of C- (58.4/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #129 out of 141 cities tested in South Dakota.
What contaminants are in Rapid City's water?
Lead was measured at 1.0 ppb (90th percentile). 392 violations are on record.
How is Rapid City's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Rapid City?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Rapid City's water come from?
Rapid City's water is sourced from Groundwater. The city has 4 water systems serving approximately 841 residents.
What health violations has Rapid City's water system had?
Rapid City has 18 health-based violations on record. The most recent violation was recorded in August 2023. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 23 violations remain unresolved.
Is Rapid City's groundwater at risk of contamination?
Rapid City uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 392 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Rapid City's water compare to other cities?
Rapid City ranks #129 out of 141 cities in South Dakota (better than 9% of state cities) and #12286 out of 15744 cities nationally (22th percentile). The grade of C- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.