F16/100
HILLSBORO WATERWORKS — Water Quality Report 2026
Serving 1,325 people · Wisconsin
Water Source
Groundwater
County
—
System ID
WI6630257
Violations
25
Contaminant Test Results
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.45 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.003 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
4
Violations (last 5yr)
0
Unresolved
2
Health-Related
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2023 – July 31, 2023Enforcement: Resolving — corrective action underway
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2023 – August 12, 2023Enforcement: Resolving — corrective action underway
TIER 2Resolved
Other non-health-based violation
When: March 11, 2023 – March 29, 2023Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 2Resolved
Consumer confidence report — content deficiency
When: September 17, 2021 – November 4, 2021Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
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 HILLSBORO WATERWORKS
Is HILLSBORO WATERWORKS water safe to drink?
HILLSBORO WATERWORKS water receives a grade of F (16/100), which is considered failing. 1 contaminant(s) exceed EPA legal limits and 25 violation(s) are on record. Customers may want to consider using a water filter.
What contaminants has HILLSBORO WATERWORKS detected?
2 contaminants were tested in HILLSBORO WATERWORKS's water. Notable contaminants include Copper (90th percentile), Lead (90th percentile). 1 exceed EPA legal limits (MCLs). 2 exceed EPA health goals (MCLGs).
Does HILLSBORO WATERWORKS have any EPA violations?
Yes, HILLSBORO WATERWORKS has 25 EPA violation(s) on record, with the most recent in 2023. Violation types include Other, TT, MR. 12 are health-based violations.
How many people does HILLSBORO WATERWORKS serve?
HILLSBORO WATERWORKS serves approximately 1,325 people, Wisconsin. The system provides water to 1 community: Hillsboro.
What type of water does HILLSBORO WATERWORKS provide?
HILLSBORO WATERWORKS sources its water from groundwater. Groundwater is pumped from underground aquifers, which often provides natural filtration. The utility's system ID is WI6630257.
How does HILLSBORO WATERWORKS compare to other utilities in Wisconsin?
HILLSBORO WATERWORKS scores 16/100 with a grade of F (failing). This score suggests significant water quality concerns relative to other utilities. Visit our Wisconsin state page for a full comparison of water systems.