01The verdict: is Dakota Dunes water safe?
Based on EPA testing data, Dakota Dunes's tap water is generally safe to drink. The water system earned a grade of A- (89.9/100), meeting federal drinking water standards across key contaminant categories. The city's 1 water system serves approximately 3,700 residents using gup.
Copper is over its legal limit
Measured at 7.60 mg/L against the EPA Action Level of 1.3 mg/L. The ledger below shows how far over — and which filter removes it.
See the measurement ↓Lead is well under the limit
90th-percentile lead is 4.0 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓A flood-prone service area
10 federal disaster declarations on record. After severe weather, watch for boil-water advisories.
See the risk factors ↓Dakota Dunes's drinking water received a grade of A- (89.9 out of 100), indicating good water quality. The city's 1 water system serves approximately 3,700 residents using gup.
Lead levels were measured at 4.0 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 3 violations on record, including 0 health-based violations. All violations have been resolved.
Dakota Dunes ranks #41 out of 137 cities in South Dakota for water quality, placing it mid-range in the state.
02What's in Dakota Dunes's water
Every contaminant flagged in Dakota Dunes, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Over Limit — EPA Action Level: 1.3 mg/L
Exceeds the EPA action level. Copper leaches from household plumbing — flush taps for 30 seconds before drinking, and consider a certified filter.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. | 4.0 | 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. | 7.60 | 1.3 | mg/L | Inorganic | Over Limit |
Cities ranked by 90th-percentile lead PF PFAS in South Dakota
Cities ranked by compounds detected Cu Copper in South Dakota
Cities ranked by 90th-percentile copper
03Dakota Dunes's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 3 violations on record, including 0 health-based violations. All violations have been resolved.
All ten of the last ten years were clean — no EPA violations recorded for Dakota Dunes.
▲ Up 2 ppb since 1993. Latest reading: 4 ppb (2025) — 27% of the action level. Sampled at higher-risk homes (90th percentile).
7.6mg/L(1993)
One sampling round on record — 585% of the 1.3mg/L EPA action level. Sampled at higher-risk homes (90th percentile).
04Where Dakota Dunes's water comes from
Dakota Dunes's water comes from groundwater under the direct influence of surface water, a designation that requires the same treatment rigor as surface water systems.
GUP
Source details for this system are limited in EPA records.
Local treatment
Treatment is regulated under the Safe Drinking Water Act.
1 system
1 water system, operated under local government ownership.
3,700 people
Residents served across Dakota Dunes's service area.
This source type is vulnerable to both surface contamination pathways and naturally occurring underground contaminants. The system is operated by local government ownership and serves approximately 3,700 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| DAKOTA DUNES CID | SD4602093 | 3,700 | GUP |
Water bodies near Dakota Dunes
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Dakota Dunes's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Industrial discharge
5 facilities within 10 miles reported 193 lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.
Flood & storm history
10 federal disaster declarations on record for Union County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
Union County is in D2 (severe drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Dakota Dunes compares
Scores for nearby South Dakota cities on one line, with the average marked.
dashed line = South Dakota average (66/100)
Dakota Dunes scores 89.9/100 — above the South Dakota average of 66/100. It outscores 8 of 10 nearby cities. Full South Dakota rankings →
58.2 / 100FRapid City, SD
38.7 / 100FAberdeen, SD
41.8 / 100AWatertown, SD
91 / 100FPine Ridge, SD
43.2 / 100DBrookings, SD
46.2 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Dakota Dunes's water — not generic advice.
Filter drinking & cooking water
Basic carbon filter for extra protection. Copper exceeds the EPA action level of 1.3 mg/L
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Dakota Dunes alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Dakota Dunes, SD tap water safe to drink?
Dakota Dunes's water quality earned a grade of A- (89.9/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #41 out of 137 cities tested in South Dakota.
What contaminants are in Dakota Dunes's water?
Lead was measured at 4.0 ppb (90th percentile). 3 violations are on record.
How is Dakota Dunes'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 Dakota Dunes?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Dakota Dunes's water come from?
Dakota Dunes's water is sourced from GUP. The city has 1 water system serving approximately 3,700 residents.
How does Dakota Dunes's water compare to other cities?
Dakota Dunes ranks #41 out of 137 cities in South Dakota (better than 70% of state cities) and #2490 out of 15382 cities nationally (84th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.