COUNTY SERVICE AREA 7
PWSID: CA4100509 · Redwood City, CA · Serves 300 people
COUNTY SERVICE AREA 7 has 7 health-based violations out of 7 total. Health violations indicate contaminant levels exceeded EPA limits or required treatment was not followed.
COUNTY SERVICE AREA 7 (PWSID CA4100509) is a cws water system drawing from a surface water source, regulated by the EPA Safe Drinking Water Information System (SDWIS) under the Safe Drinking Water Act. It serves approximately 300 people in Redwood City, CA, and is subject to primacy enforcement by the California drinking-water program.
The system's federal compliance record contains 7 total violations, with 7 classified as health-based (MCL exceedances or treatment-technique failures). 2 distinct contaminants have been cited, including Total Trihalomethanes (TTHM), Haloacetic Acids (HAA5). Recorded violations span 2017–2025.
A historical violation does not necessarily describe current water quality, systems must notify customers and remediate, and monitoring-type violations often reflect reporting lapses rather than contamination. The most authoritative real-time source is the utility's annual Consumer Confidence Report. For enforcement history and corrective-action orders, consult EPA ECHO and the California state drinking-water program's public portal.
System Details
- EPA ID (PWSID)
- CA4100509
- System Type
- CWS
- Water Source
- Surface Water
- Location
- Redwood City, CA
- Population Served
- 300
- Health Violations
- Yes (7)
What contaminants are in this water system?
| Contaminant | Violations | Health-Based |
|---|---|---|
| Total Trihalomethanes (TTHM) | 4 | 4 |
| Haloacetic Acids (HAA5) | 3 | 3 |
Violation History (7)
| Contaminant | Health | Date |
|---|---|---|
| Haloacetic Acids (HAA5) | Yes | Jan 1, 2025 |
| Haloacetic Acids (HAA5) | Yes | Jan 1, 2025 |
| Haloacetic Acids (HAA5) | Yes | Jan 1, 2020 |
| Total Trihalomethanes (TTHM) | Yes | Apr 1, 2018 |
| Total Trihalomethanes (TTHM) | Yes | Jan 1, 2018 |
| Total Trihalomethanes (TTHM) | Yes | Oct 1, 2017 |
| Total Trihalomethanes (TTHM) | Yes | Jul 1, 2017 |
Frequently Asked Questions
Is COUNTY SERVICE AREA 7 water safe to drink?
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About This Data
Water system data is from the EPA Safe Drinking Water Information System (SDWIS). Health-based violations include Maximum Contaminant Level (MCL) and Treatment Technique (TT) violations that may pose a direct risk to public health. Violation records may span multiple years.
Source: U.S. Environmental Protection Agency, SDWIS Federal Reporting Services U.S. Environmental Protection Agency, SDWIS Federal Reporting Services
Read our methodology - how this data is sourced, computed, and verified.