Is South Sioux City, NE Tap Water Safe to Drink?
Graded B+ — but Copper and 1,4-Dioxane were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
81/100
waterverge.com South Sioux City, NE — Water Quality Report
South Sioux City's drinking water received a grade of B+ (81 out of 100), indicating good water quality. The city's 2 water systems serve approximately 14,143 residents using gup.
Lead levels were measured at 1.1 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.
The system has 11 violations on record, including 2 health-based violations. 5 remain unresolved.
What to know about South Sioux City's water
South Sioux City ranks #162 out of 200 cities in Nebraska for water quality, placing it among the lowest-rated in the state.
PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.
Water quality score
See methodology →Is South Sioux City, NE water safe to drink?
South Sioux City's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (81/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 14,143 residents using gup.
Recent water quality updates for South Sioux City
A timeline of significant water quality events, violations, and data updates.
Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.
Latest EPA compliance and testing data incorporated into South Sioux City's water quality assessment. Grade: B+ (81/100).
Contaminants: LEAD AND COPPER RULE REVISIONS.
Federal disaster declaration (FEMA DR-4420). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4013). Flood event — may have impacted local water infrastructure.
1 health-based. Contaminants: Coliform (TCR).
Key contaminant findings
Based on the most recent EPA sampling data for South Sioux 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.
Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.
Violation history
South Sioux City's water system has 11 total violations on record, including 2 health-based violations. 5 remain unresolved. 1 violation was issued in the last 5 years.
Flood & environmental risk
Dakota County has experienced 8 federally declared disasters since 1967. 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 Big Sioux River, Missouri River At Sioux City, Perry Creek Near Hinton, Perry Creek At 38Th Street At Sioux City, Floyd River At James.
Where does South Sioux City's water come from?
South Sioux City's drinking water comes from gup, supplied by 2 water systems serving approximately 14,143 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Big Sioux River (river), Missouri River At Sioux City (river), Perry Creek Near Hinton (river), Perry Creek At 38Th Street At Sioux City (river), Floyd River At James (river).
What South Sioux City residents can do
Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in South Sioux 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.
South Sioux 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 South Sioux City
Industrial polluters nearby
Reported releases to surface water by facilities near South Sioux City, ranked by pounds discharged annually.
Total reported releases to surface water: 944,171 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
CF INDUSTRIES NITROGEN LLC-PORT NEAL NITROGEN COMPLEX SERGEANT BLUFF, IA51054 | Nitrate compounds (water dissociable; reportable only when in aqueous solution) | 876,722 | 9.6 mi |
GELITA SERGEANT BLUFF, IA51054 | Ammonia | 67,134 | 8.5 mi |
VALMONT COATINGS INC DBA SIOUXLAND GALVANIZING CORP. SIOUX CITY, IA51111 | Zinc compounds | 177 | 2.8 mi |
MIDAMERICAN ENERGY CO GEORGE NEAL NORTH SERGEANT BLUFF, IA51054 | Barium And Barium Compounds | 123 | 9.6 mi |
CARGILL FEED & NUTRITION SIOUX CITY SIOUX CITY, IA51105 | Zinc compounds | 15 | 5.1 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Drought conditions
D2 — severe droughtDakota County is currently in D2 (severe 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
Dakota County has experienced 8 federally declared disasters since 1967. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in South Sioux 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. | 1.1 | 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. | 1.80 | 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. | 97.300 | 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. | ND | HI | µg/L | PFAS | Not 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. | ND | 0.004 | µg/L | PFAS | Not Detected |
| 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 South Sioux City compares by contaminant
Explore where South Sioux City ranks among all Nebraska cities for specific contaminants.
Water source & infrastructure
Where South Sioux City's water comes from
South Sioux City's water comes from groundwater under the direct influence of surface water, a designation that requires the same treatment rigor as surface water systems.
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 14,143 people through 2 water systems.
Water bodies near South Sioux City
South Sioux 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 South Sioux City
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SOUTH SIOUX CITY, CITY OF | NE3104309 | 14,043 | GUP |
| CRYSTAL LAKE MHP, LLC | NE3104308 | 100 | GWP |
How South Sioux City compares
Full Nebraska rankings →South Sioux City's score of 81/100 is above the average of 66/100 among major Nebraska cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Nebraska rankings →About South Sioux City, NE
Wikipedia →South Sioux City is a city in Dakota County, Nebraska, United States. It is located immediately across the Missouri River from Sioux City, Iowa, and is part of the Sioux City metropolitan area. As of the 2020 census, the city population was 14,043, making it the 14th most populous city in Nebraska.
Learn more about your water
Guides and resources related to South Sioux City's water quality findings.
Explore water quality across Dakota
Frequently asked questions
Is South Sioux City, NE tap water safe to drink?
South Sioux City's water quality earned a grade of B+ (81/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #162 out of 200 cities tested in Nebraska.
What contaminants are in South Sioux City's water?
Lead was measured at 1.1 ppb (90th percentile). 1 PFAS compound was detected. 11 violations are on record.
How is South Sioux 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 South Sioux City?
PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.
Where does South Sioux City's water come from?
South Sioux City's water is sourced from GUP. The city has 2 water systems serving approximately 14,143 residents.
What health violations has South Sioux City's water system had?
South Sioux City has 2 health-based violations on record. The most recent violation was recorded in October 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 5 violations remain unresolved.
How does South Sioux City's water compare to other cities?
South Sioux City ranks #162 out of 200 cities in Nebraska (better than 19% of state cities) and #7616 out of 15744 cities nationally (52th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.