Is Rapid City, SD tap water safe?

Data: U.S. EPA · How we read the data · How we check it

No federal limits exceeded in EPA data for Rapid City Water System. 1 PFAS were detected below the limits.

40 public water systems serve parts of Rapid City. The largest, Rapid City Water System, serves 72,009 people. Your water bill names your system.

Largest system

Rapid City Water System

72,009 people · Surface water · EPA ID SD4600406

PFAS	Highest average	Limit	Status
PFOA Not detected	–	4 ppt	Not detected
PFOS Not detected	–	4 ppt	Not detected
PFHxS Detected, below limit	4.85 ppt	10 ppt	Detected, below limit
PFNA Not detected	–	10 ppt	Not detected
HFPO-DA (GenX) Not detected	–	10 ppt	Not detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

Lead: 6 ppb at the 90th percentile (Dec 2024, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0

Full Rapid City Water System results

Across South Dakota, 0 of 55 water systems EPA tested had PFAS above a 2024 federal limit, and 0 systems were above the lead action level in results from the last five years. South Dakota results.

Rapid City homes and lead pipes

53%

of homes built before 1980 (South Dakota 50%, US 50%)

11%

built before 1950 (South Dakota 20%)

37%

of households rent (South Dakota 31%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Rapid City city (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Rapid City

Rapid Valley Sanitary District
11,408 people · Surface water · South Dakota · lists this city
PFOS detectedAlso: PFHxS detected · Lithium above screening level
Colonial Pine Hills Sanitary Distric Water System
1,200 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Chapel Lane Water Company
1,200 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Wonderland Homes Water System
750 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Sun Valley Development Water System
650 people · Groundwater · South Dakota · lists this city
No PFAS above limits
Hisega Meadows Water Inc
493 people · Groundwater under influence of surface water · South Dakota · lists this city
Not in EPA's PFAS sample

33 more systems

Hart Ranch Water System
468 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Pine Grove Water System
425 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
South Canyon Country Estates Water System
420 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Weston Heights Homeowners Associatio Water System
412 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016
The Ranch at Black Gap Water System
375 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Prairie Acres LLC
350 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016
Stagebarn Sanitary District
295 people · Purchased groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Prairie Acres North Water System
288 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016
Golden Valley Water Company
283 people · Groundwater · South Dakota · lists this city
Radium (combined 226/228) violationsAlso: Gross alpha violations
Timberwood Park Estates Water System
283 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Carriage Hills Water System
267 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Happy Holiday RV Resort Water System
264 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016
Sunset Ranch Water System
263 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Dry Creek Estates Water System
233 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sampleAlso: 2 health-based violations since 2016
Boulder Park Water Users Association
200 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Pine Cliff Estates Water System
180 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Rapid City Mobile Home Park Water System
170 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Prairie Acres South Water System
170 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016
Strato Rim Estates Water Company
170 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Canyon Springs Water and Sewer Distr
163 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Westberry Trails Water Users Association
155 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Ponderosa Mobile Home Ranch Water System
150 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016
B & J Mobile Home Park Water System
135 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Midland Heights Water System
130 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
East Ridge Acres Water System
118 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Elk Creek Village Water System
110 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Prairie Haven Subdivision
105 people · Groundwater · South Dakota · lists this city
Gross alpha violations
Ponderosa Ridge Water System
98 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Spring Canyon Water Company
92 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Ar Ranch Water System
88 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sample
Spearfish Meadows Water System
87 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016
Sheridan Lake Highlands, Inc.
85 people · Groundwater · South Dakota · lists this city
Haloacetic acids (HAA5) violation
Rock Ridge Court Water System
74 people · Groundwater · South Dakota · lists this city
Not in EPA's PFAS sampleAlso: 1 health-based violation since 2016

How nearby cities compare

City	Main water system	PFAS	Lead (90th pct.)
Aberdeen 254 mi Aberdeen Water System	Aberdeen Water System	None above limits	3 ppb
Brookings 319 mi Brookings Municipal Utilities	Brookings Municipal Utilities	None above limits	8 ppb
Sioux Falls 324 mi Sioux Falls Water System	Sioux Falls Water System	None above limits	3 ppb

Rapid City ZIP codes (1)

57701

Questions

Is Rapid City tap water safe to drink?

Rapid City Water System has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Rapid City, SD?

40 public water systems serve parts of Rapid City. The largest is Rapid City Water System (72,009 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Rapid City tap water have PFAS?

Rapid City Water System had 1 PFAS detected at least once in EPA's 2023–2025 testing, all with averages below the federal limits.

Do Rapid City homes have lead pipes?

Census estimates put 53% of Rapid City homes as built before 1980 (South Dakota: 50%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Rapid City Water System's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.