A91/100
TOWN OF HILLSBOROUGH — Water Quality Report 2026
Serving 11,766 people · California
Water Source
Purchased Surface Water
County
—
System ID
CA4110016
Violations
2
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.006 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2014.
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 TOWN OF HILLSBOROUGH
Is TOWN OF HILLSBOROUGH water safe to drink?
TOWN OF HILLSBOROUGH water receives a grade of A (91/100), which is considered excellent. Out of 69 contaminants tested, none exceed EPA legal limits. 1 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.
What contaminants has TOWN OF HILLSBOROUGH detected?
69 contaminants were tested in TOWN OF HILLSBOROUGH's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does TOWN OF HILLSBOROUGH have any EPA violations?
Yes, TOWN OF HILLSBOROUGH has 2 EPA violation(s) on record, with the most recent in 2014. Violation types include MCL, MR. 1 are health-based violations.
How many people does TOWN OF HILLSBOROUGH serve?
TOWN OF HILLSBOROUGH serves approximately 11,766 people, California.
What type of water does TOWN OF HILLSBOROUGH provide?
TOWN OF HILLSBOROUGH sources its water from purchased surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is CA4110016.
How does TOWN OF HILLSBOROUGH compare to other utilities in California?
TOWN OF HILLSBOROUGH scores 91/100 with a grade of A (excellent). This places it among the higher-performing utilities in the state. Visit our California state page for a full comparison of water systems.