Is Rapid City, SD Tap Water Safe to Drink?
Graded F — but Copper, Strontium and 1 more were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
38.7/100
waterverge.com Rapid City, SD — Water Quality Report
Rapid City's drinking water received a grade of F (38.7 out of 100), indicating failing water quality. The city's 67 water systems serve approximately 95,834 residents using surface water.
Lead levels were measured at 1.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 3 PFAS compounds, with levels exceeding EPA maximum contaminant levels in the water supply.
The system has 3413 violations on record, including 349 health-based violations. 165 remain unresolved.
What to know about Rapid City's water
Rapid City ranks #141 out of 141 cities in South Dakota for water quality, placing it among the lowest-rated in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
Of particular concern: PFAS "forever chemical" levels exceed the 2024 EPA maximum contaminant levels. These synthetic compounds don't break down naturally and require specialized filtration such as reverse osmosis or granular activated carbon.
Hexavalent chromium (chromium-6) was detected at 0.28 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.
The system has seen 63 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
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 F (38.7/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 67 water systems serve approximately 95,834 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Rapid City
A timeline of significant water quality events, violations, and data updates.
PFAS levels exceed EPA maximum contaminant levels. Reverse osmosis or activated carbon filtration recommended.
Latest EPA compliance and testing data incorporated into Rapid City's water quality assessment. Grade: F (38.7/100).
1 health-based. Contaminants: Stage 1 Disinfectants and Disinfection Byproducts Rule.
1 health-based. Contaminants: Combined Radium (-226 and -228).
2 health-based. Contaminants: Stage 1 Disinfectants and Disinfection Byproducts Rule, Revised Total Coliform Rule, Combined Radium (-226 and -228).
Federal disaster declaration (FEMA DR-4463). 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.
PFAS "forever chemicals" exceed EPA maximum contaminant levels. Reverse osmosis or granular activated carbon filtration strongly recommended.
PFAS "forever chemicals" detected
UCMR 5 testing found 3 PFAS compounds in Rapid City's water supply. PFAS are synthetic chemicals that persist indefinitely in the environment and the human body.
Violation history
Rapid City's water system has 3,413 total violations on record, including 349 health-based violations. 165 remain unresolved. 63 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 surface water (rivers, lakes, or reservoirs), supplied by 67 water systems serving approximately 95,834 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. 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: Reverse osmosis system. 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 ↓Forever chemicals overview
National PFAS report →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. | 4.00 | 1.3 | mg/L | Inorganic | Over Limit |
| 11Cl-PF3OUdS | ND | HI | µg/L | PFAS | Not Detected |
| 4:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 6:2 FTS 6:2 FTSPFAS A fluorotelomer sulfonate commonly found at sites contaminated with aqueous film-forming foam (AFFF) used in firefighting. Health EffectsPotential liver toxicity and endocrine disruption. Less studied but identified as a contaminant of concern. EPA LimitNo individual MCL (not yet regulated) Common SourcesFirefighting foam (AFFF), airports, military bases, and industrial facilities. | ND | HI | µg/L | PFAS | Not Detected |
| 8:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 9Cl-PF3ONS | ND | HI | µg/L | PFAS | Not Detected |
| ADONA | ND | HI | µg/L | PFAS | Not Detected |
| HFPO-DA HFPO-DA (GenX)PFAS A replacement for PFOA in manufacturing, marketed as safer but still a persistent "forever chemical." Also known as GenX. Health EffectsLiver and kidney effects, reproductive toxicity, immune system effects, and potential cancer risk. EPA Limit10 ppt MCL Common SourcesFluoropolymer manufacturing (used as PFOA replacement), industrial wastewater discharge. | ND | 0.01 | µg/L | PFAS | Not Detected |
| lithium LithiumInorganic A naturally occurring alkali metal found in groundwater. Monitored under UCMR 5 to assess occurrence in drinking water. Health EffectsKidney effects at high doses. Low-level exposure effects under study; some research suggests neurological effects. EPA LimitNo MCL (monitoring only under UCMR 5) Common SourcesNatural mineral deposits, geothermal water, and industrial discharge. | 23.400 | HI | µg/L | PFAS | Detected |
| NEtFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| NFDHA | ND | HI | µg/L | PFAS | Not Detected |
| NMeFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| PFBA PFBAPFAS One of the shortest-chain PFAS compounds. Very mobile in water and difficult to remove with standard filtration. Health EffectsThyroid effects, potential developmental toxicity. Shorter half-life in body than long-chain PFAS. EPA LimitNo individual MCL (not yet regulated) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and firefighting foam. | ND | HI | µg/L | PFAS | Not Detected |
| PFBS PFBSPFAS A short-chain PFAS used as a replacement for PFOS. While it clears the body faster than long-chain PFAS, it still persists in the environment. Health EffectsThyroid effects, reproductive and developmental toxicity, kidney effects. EPA LimitPart of Hazard Index (1.0) Common SourcesIndustrial discharge, firefighting foam, and as a replacement chemical in manufacturing. | ND | HI | µg/L | PFAS | Not Detected |
| PFDA | ND | HI | µg/L | PFAS | Not Detected |
| PFDoA | ND | HI | µg/L | PFAS | Not Detected |
| PFEESA | ND | HI | µg/L | PFAS | Not Detected |
| PFHpA PFHpAPFAS A medium-chain PFAS compound found in various environmental samples. Less studied than PFOA/PFOS but still considered a contaminant of concern. Health EffectsLiver effects, potential developmental toxicity, and endocrine disruption. EPA LimitPart of Hazard Index (1.0) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFHpS | ND | HI | µg/L | PFAS | Not Detected |
| PFHxA PFHxAPFAS A short-chain PFAS replacement chemical widely used after manufacturers phased out longer-chain PFAS. Very commonly detected in water. Health EffectsLiver and kidney effects, potential thyroid disruption. Considered less toxic than long-chain PFAS but still persistent. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial processes, firefighting foam (AFFF), food packaging, and textile treatment. | ND | HI | µg/L | PFAS | Not Detected |
| PFHxS PFHxSPFAS A medium-chain PFAS found in firefighting foam and consumer products. It has a long half-life in the human body, similar to long-chain PFAS. Health EffectsImmune system effects, thyroid disruption, and potential reproductive and developmental harm. EPA LimitPart of Hazard Index (1.0) Common SourcesFirefighting foam (AFFF), waterproof textiles, food packaging, and industrial discharge. | 0.006 | HI | µg/L | PFAS | Detected |
| PFMBA | ND | HI | µg/L | PFAS | Not Detected |
| PFMPA | ND | HI | µg/L | PFAS | Not Detected |
| PFNA PFNAPFAS A long-chain PFAS compound used in manufacturing fluoropolymers. It bioaccumulates in the body and is very persistent in the environment. Health EffectsDevelopmental effects, liver toxicity, immune suppression, and potential cancer risk. EPA LimitPart of Hazard Index (1.0) Common SourcesFluoropolymer manufacturing, industrial emissions, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFOA PFOAPFAS A long-chain PFAS ("forever chemical") once widely used in nonstick coatings and firefighting foam. It persists in the body and environment for years. Health EffectsLinked to kidney and testicular cancer, thyroid disease, elevated cholesterol, and reproductive issues. EPA Limit4.0 ppt MCL Common SourcesIndustrial discharge, firefighting foam (AFFF), nonstick cookware manufacturing, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFOS PFOSPFAS A long-chain PFAS compound historically used in stain-resistant coatings and firefighting foam. One of the most studied and persistent PFAS chemicals. Health EffectsLiver damage, immune system suppression, thyroid disruption, increased cholesterol, and potential cancer risk. EPA Limit4.0 ppt MCL Common SourcesFirefighting foam (AFFF), industrial sites, stain-resistant fabric treatments, and contaminated groundwater. | 0.006 | 0.004 | µg/L | PFAS | Over MCL |
| PFPeA PFPeAPFAS A short-chain PFAS compound commonly detected in drinking water. One of the most frequently found PFAS in UCMR 5 monitoring. Health EffectsLess studied than PFOA/PFOS. Potential liver and thyroid effects. Research is ongoing. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial discharge, firefighting foam degradation, and consumer products. | ND | HI | µg/L | PFAS | Not Detected |
| PFPeS | ND | HI | µg/L | PFAS | Not Detected |
| PFTA | ND | HI | µg/L | PFAS | Not Detected |
| PFTrDA | ND | HI | µg/L | PFAS | Not Detected |
| PFUnA | ND | HI | µg/L | PFAS | Not Detected |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
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 comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by local government ownership and serves approximately 95,834 people through 67 water systems.
Water bodies near Rapid City
Rapid City is located near 5 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Rapid City
| System Name | PWSID | Population | Source |
|---|---|---|---|
| RAPID CITY | SD4600406 | 72,009 | SW |
| RAPID VALLEY SANITARY DISTRICT | SD4600274 | 11,408 | SW |
| COLONIAL PINE HILLS SANITARY DISTRIC | SD4600263 | 1,200 | GW |
| CHAPEL LANE WATER COMPANY | SD4600264 | 1,200 | GW |
| WONDERLAND HOMES | SD4600421 | 750 | GW |
| SUN VALLEY DEVELOPMENT | SD4602270 | 650 | GW |
| HISEGA MEADOWS WATER INC | SD4600271 | 491 | GU |
| HART RANCH | SD4600910 | 438 | GW |
| PINE GROVE | SD4600948 | 425 | GW |
| SOUTH CANYON COUNTRY ESTATES | SD4600627 | 420 | GW |
| WESTON HEIGHTS HOMEOWNERS ASSOCIATIO | SD4600862 | 412 | GW |
| THE RANCH AT BLACK GAP | SD4602203 | 375 | GW |
| PRAIRIE ACRES LLC | SD4600014 | 350 | GW |
| STAGEBARN SANITARY DISTRICT | SD4602159 | 295 | GWP |
| PRAIRIE ACRES NORTH | SD4600884 | 288 | GW |
| GOLDEN VALLEY WATER COMPANY | SD4602261 | 283 | GW |
| CARRIAGE HILLS | SD4600265 | 267 | GW |
| HAPPY HOLIDAY RV RESORT | SD4600669 | 264 | GW |
| SUNSET RANCH | SD4602263 | 263 | GW |
| DRY CREEK ESTATES | SD4602241 | 233 | GW |
| BOULDER PARK WATER USERS ASSOCIATION | SD4602005 | 200 | GW |
| PINE CLIFF ESTATES | SD4600270 | 180 | GW |
| RAPID CITY MOBILE HOME PARK | SD4600257 | 170 | GW |
| PRAIRIE ACRES SOUTH | SD4600428 | 170 | GW |
| STRATO RIM ESTATES WATER COMPANY | SD4602191 | 170 | GW |
| CANYON SPRINGS WATER AND SEWER DISTR | SD4602311 | 163 | GW |
| TIMBERWOOD PARK ESTATES | SD4602272 | 158 | GW |
| WESTBERRY TRAILS WATER USERS ASSOC | SD4600253 | 155 | GW |
| B & J MOBILE HOME PARK | SD4602122 | 135 | GW |
| MIDLAND HEIGHTS | SD4600515 | 130 | GW |
| EAST RIDGE ACRES | SD4601000 | 118 | GW |
| ELK CREEK VILLAGE | SD4602237 | 110 | GW |
| PRAIRIE HAVEN SUBDIVISION | SD4602322 | 105 | GW |
| PONDEROSA MOBILE HOME RANCH | SD4600260 | 100 | GW |
| PONDEROSA RIDGE | SD4600863 | 90 | GW |
| SPRING CANYON WATER COMPANY | SD4600015 | 89 | GW |
| AR RANCH | SD4602379 | 88 | GW |
| SPEARFISH MEADOWS | SD4600875 | 87 | GW |
| SHERIDAN LAKE HIGHLANDS, INC. | SD4602285 | 85 | GW |
| ROCK RIDGE COURT | SD4602209 | 74 | GW |
| EDELWEISS MOUNTAIN IMPROVEMENT ASSOC | SD4600273 | 70 | GW |
| THRALL MTN. PROPERTY OWNERS ASSOCIAT | SD4600513 | 70 | GW |
| SIPHON HILL WATER ASSOCIATION | SD4600272 | 68 | GW |
| RIMROCK HIGHLAND ESTATES COMM ASSOC | SD4602231 | 66 | GW |
| WHISPERING WILLOWS | SD4602094 | 64 | GWP |
| COPPER OAKS I | SD4602136 | 64 | GWP |
| ELK VALLEY RANCHETTES | SD4602189 | 62 | GW |
| HIGH MEADOWS RANCHETTES | SD4600011 | 60 | GW |
| ELK CREEK VALLEY VIEW ASSOC | SD4602363 | 52 | GW |
| WEST NIKE SUBDIVISION | SD4602260 | 50 | GWP |
| GOLDEN HILLS HOMES | SD4602213 | 47 | GW |
| WHISPERING PINES WATER ASSOCIATION | SD4600268 | 45 | GW |
| BOXELDER HIGH COUNTRY ASSOCIATION | SD4602276 | 45 | GW |
| CEDAR GULCH 1 | SD4602301 | 45 | GW |
| CAVALRY TRAILS HOMEOWNER ASSOCIATION | SD4602106 | 44 | GW |
| CEDAR GULCH 2 | SD4602295 | 40 | GW |
| HIGHLAND HILLS | SD4600050 | 38 | GW |
| HIGH SHERIDAN RANCH | SD4602234 | 38 | GW |
| HAPPY HOLIDAY WATER ASSOCIATION | SD4600420 | 35 | GW |
| RIMROCK RIDGE WATER ASSOCIATION | SD4602084 | 35 | GW |
| RIMROCK HEIGHTS HOMEOWNERS ASSOCIATI | SD4602356 | 35 | GW |
| PONDEROSA PARK | SD4600405 | 31 | GW |
| NORRIS PEAK WATER USERS ASSOC | SD4602349 | 30 | GW |
| HIDDEN VALLEY WATER ASSOCIATION INC | SD4600269 | 27 | GW |
| DARLINGTON ESTATES | SD4600403 | 25 | GW |
| PONDEROSA WATER COMPANY | SD4602134 | 25 | GW |
| PINEVIEW WATER ASSOCIATION | SD4602153 | 25 | GW |
How Rapid City compares
Full South Dakota rankings →Rapid City's score of 38.7/100 is below the average of 68/100 among major South Dakota cities. 10 of 10 nearby cities score higher.
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 F (38.7/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #141 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). 3 PFAS compounds were detected. 3413 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?
PFAS compounds exceed EPA limits — a reverse osmosis or activated carbon filter is recommended.
Where does Rapid City's water come from?
Rapid City's water is sourced from Surface water. The city has 67 water systems serving approximately 95,834 residents.
What health violations has Rapid City's water system had?
Rapid City has 349 health-based violations on record. The most recent violation was recorded in November 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 165 violations remain unresolved.
Why does Rapid City have so many PFAS compounds in its water?
3 different PFAS "forever chemical" compounds were detected in Rapid City's water supply during UCMR 5 testing. PFAS contamination often originates from proximity to military installations (AFFF firefighting foam), airports, industrial manufacturing sites, or wastewater treatment facilities. Some levels exceed the 2024 EPA maximum contaminant levels — a reverse osmosis or NSF-certified activated carbon filter is strongly recommended.
How does Rapid City's water compare to other cities?
Rapid City ranks #141 out of 141 cities in South Dakota (better than 0% of state cities) and #15308 out of 15744 cities nationally (3th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.