B74/100
LYON-SIOUX RWS-BIG SIOUX — Water Quality Report 2026
Serving 1,530 people · Iowa
Water Source
Groundwater
County
—
System ID
IA6000755
Violations
15
Contaminant Test Results
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 3.20 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.003 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2019.
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
Frequently Asked Questions About LYON-SIOUX RWS-BIG SIOUX
Is LYON-SIOUX RWS-BIG SIOUX water safe to drink?
LYON-SIOUX RWS-BIG SIOUX water receives a grade of B (74/100), which is considered good. Out of 32 contaminants tested, 1 exceed EPA legal limits. 2 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has LYON-SIOUX RWS-BIG SIOUX detected?
32 contaminants were tested in LYON-SIOUX RWS-BIG SIOUX's water. Notable contaminants include Copper (90th percentile), Lead (90th percentile). 1 exceed EPA legal limits (MCLs). 2 exceed EPA health goals (MCLGs).
Does LYON-SIOUX RWS-BIG SIOUX have any EPA violations?
Yes, LYON-SIOUX RWS-BIG SIOUX has 15 EPA violation(s) on record, with the most recent in 2019. Violation types include MR.
How many people does LYON-SIOUX RWS-BIG SIOUX serve?
LYON-SIOUX RWS-BIG SIOUX serves approximately 1,530 people, Iowa. The system provides water to 1 community: Rock Rapids.
What type of water does LYON-SIOUX RWS-BIG SIOUX provide?
LYON-SIOUX RWS-BIG SIOUX sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is IA6000755.
How does LYON-SIOUX RWS-BIG SIOUX compare to other utilities in Iowa?
LYON-SIOUX RWS-BIG SIOUX scores 74/100 with a grade of B (good). This is an above-average performance for utilities statewide. Visit our Iowa state page for a full comparison of water systems.