Is Stephan, SD Tap Water Safe to Drink?
Graded B+ — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
80/100
waterverge.com Stephan, SD — Water Quality Report
Stephan's drinking water received a grade of B+ (80 out of 100), indicating good water quality. The city's 1 water system serves approximately 516 residents using purchased surface water.
Lead levels were measured at 0.5 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 27 violations on record, including 1 health-based violation. 5 remain unresolved.
What to know about Stephan's water
Stephan ranks #97 out of 141 cities in South Dakota for water quality, placing it below average 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.
As a small community water system, Stephan may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 7 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Stephan, SD water safe to drink?
Stephan's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (80/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 516 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Stephan
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Stephan's water quality assessment. Grade: B+ (80/100).
Contaminants: Revised Total Coliform Rule, Long Term 2 Enhanced Surface Water Treatment Rule.
Contaminants: Total Haloacetic Acids (HAA5), TTHM.
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-4440). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-1984). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Stephan'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
Stephan's water system has 27 total violations on record, including 1 health-based violation. 5 remain unresolved. 7 violations were issued in the last 5 years.
Flood & environmental risk
Hyde County has experienced 7 federally declared disasters since 1969. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Stephan's water come from?
Stephan's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 516 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment.
What Stephan residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Stephan'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.
Stephan'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
Flood & disaster history
Hyde County has experienced 7 federally declared disasters since 1969. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Stephan'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. | 0.5 | 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. | 1.52 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.520 mg/L (2018)
EPA action level: 1.3 mg/L
See how Stephan compares by contaminant
Explore where Stephan ranks among all South Dakota cities for specific contaminants.
Water source & infrastructure
Where Stephan's water comes from
Stephan'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 federal ownership and serves approximately 516 people through 1 water system.
Water systems serving Stephan
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CROW CREEK TRIBAL SCHOOL | 084690437 | 516 | SWP |
How Stephan compares
Full South Dakota rankings →Stephan's score of 80/100 is above the average of 66/100 among major South Dakota cities. It outscores 6 of 10 nearby cities.
Nearby cities
View South Dakota rankings →ZIP codes served by Stephan
The water system serving Stephan covers 1 ZIP code. Select any ZIP to see which water systems serve that area.
About Stephan, SD
Wikipedia →Stephan is an unincorporated community and census-designated place (CDP) in Hyde County, South Dakota, United States. Stephan has been assigned the ZIP code of 57346. The population of the CDP was 68 at the 2020 census.
Learn more about your water
Guides and resources related to Stephan's water quality findings.
Frequently asked questions
Is Stephan, SD tap water safe to drink?
Stephan's water quality earned a grade of B+ (80/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #97 out of 141 cities tested in South Dakota.
What contaminants are in Stephan's water?
Lead was measured at 0.5 ppb (90th percentile). 27 violations are on record.
How is Stephan'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 Stephan?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Stephan's water come from?
Stephan's water is sourced from Purchased surface water. The city has 1 water system serving approximately 516 residents.
What health violations has Stephan's water system had?
Stephan has 1 health-based violation on record. The most recent violation was recorded in February 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 5 violations remain unresolved.
How does Stephan's water compare to other cities?
Stephan ranks #97 out of 141 cities in South Dakota (better than 31% of state cities) and #8073 out of 15744 cities nationally (49th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Stephan's small water system affect quality?
Stephan's system serves approximately 516 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 27 violations on record.