B63/100
North Sioux City Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 3,042 residents · South Dakota
What's In North Sioux City's Tap Water?
1
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.004 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2008.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
NORTH SIOUX CITY
Population Served
3,042
Water Source
Groundwater
System ID
SD4600226
Frequently Asked Questions About North Sioux City Water
Is North Sioux City tap water safe to drink?
North Sioux City, South Dakota tap water receives a grade of B (63/100), which is considered good. Out of 1 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 1 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in North Sioux City's water?
Of the 1 contaminants tested in North Sioux City's water supply, the most notable include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does North Sioux City have any water quality violations?
Yes, North Sioux City has 34 EPA violation(s) on record, with the most recent in 2008. Violation types include MR, Other. None of these are classified as health-based violations.
Do I need a water filter in North Sioux City?
North Sioux City water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does North Sioux City's tap water come from?
North Sioux City's drinking water is sourced from groundwater and supplied by NORTH SIOUX CITY. The system serves approximately 3,042 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is North Sioux City's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. North Sioux City's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does North Sioux City's water compare to other cities in South Dakota?
North Sioux City's water quality score of 63/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our South Dakota state page to see how all cities in the state compare.
What should I do if I'm concerned about North Sioux City's water quality?
If you have concerns about North Sioux City's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (NORTH SIOUX CITY) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.