B
77

Good Water Quality

San Martin, CA 95046

Santa Clara County · Population served: 961 · Data updated March 2026

Water Systems Serving This Area

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SAN MARTIN COUNTY WATER DISTRICT
Groundwater · Pop. 627
PWSID: CA4300542
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RANCHO ROBLES MUTUAL WATER COMPANY
Groundwater · Pop. 103
PWSID: CA4300577
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SAN MARTIN FOOTHILLS WATER COMPANY
Groundwater · Pop. 145
PWSID: CA4300638
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CHIRI SWEET WATER COMPANY
Groundwater · Pop. 40
PWSID: CA4300757
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SOUTH COUNTY RETIREMENT HOME
Groundwater · Pop. 46
PWSID: CA4300832

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
60.0
15 ppb 1 ppb Exceeded

Violation History (Last 5 Years)

1Total (5yr)
0Health-Based
0Major

Water Quality Summary

Understanding Your Water in San Martin

Tap water quality in San Martin, California (95046) receives an overall grade of B (Good) with a score of 77 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is roughly in line with the California state average of 81. The area is served by 5 water systems providing water to approximately 961 people, using groundwater sources. Testing has found elevated levels of Lead that warrant attention.

Your Score 77/100 B
vs State 4 pts below California avg (81)
vs National 2 pts above national avg (75)

What a Grade B Means

A score of 77/100 means the water in San Martin, CA is generally good and meets EPA standards, with only minor areas of concern. There may be low levels of detectable contaminants or a small number of non-critical violations. Most residents can feel comfortable with their tap water quality, though basic filtration can provide an extra layer of protection.

Groundwater: drawn from underground aquifers via wells

Health Information

What These Contaminants Mean for You

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Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

Common Questions

Frequently Asked Questions

Based on EPA data, tap water in San Martin, California receives a grade of B (Good) with a score of 77/100. This indicates the water meets federal standards and has relatively few concerns. However, individual homes may still have localized issues such as lead from old plumbing.

ZIP code 95046 is served by 5 water systems using groundwater sources, providing water to approximately 961 people. Groundwater is naturally filtered through rock and soil, often requiring less treatment. However, it can be vulnerable to contamination from underground sources like naturally occurring arsenic, nitrates from agriculture, or PFAS from industrial sites.

Yes — lead levels in San Martin, California are 60.0 ppb, which exceeds the EPA action level of 15 ppb. This is a serious concern. We strongly recommend using a certified lead-removal filter for all drinking and cooking water, and having your water independently tested.

No PFAS ("forever chemicals") were detected in water systems serving San Martin, California during the most recent EPA monitoring period (UCMR5). However, not all water systems have been tested for all PFAS compounds, and new contamination can occur over time.

Water systems serving San Martin, California have received 1 violation in the last 5 years. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.

Based on detected contaminants (lead), residents in San Martin, California should consider: NSF/ANSI 53 certified filter — specifically rated for lead reduction. Pitcher filters (like Brita Longlast or PUR) and under-sink systems both work. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.

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