CITY REPORT CA

Alamo, CA Water Safety: 55/100 (2026)

1 ZIP code · 2 water systems · Updated 2026-06-03

Alamo, CA: mid-range safety grade, uneven compliance across service areas.

How Alamo Compares

Alamo55/100
California avg73/100
National avg67/100

Data: EPA SDWIS Last verified: 2026-06-03

1
ZIP Codes
2
Water Systems
0
ZIPs with Violations
C · 55
Avg Safety Score
Zone 2
Radon Risk (Moderate)
$2.0M
Median Home Value
$2,100
Est. Remediation (0.1% of home value)

What You Should Know About Alamo Water

  • Homes built before 1986: 66% — older plumbing may contain lead solder.
  • Estimated remediation: $2,100 per household.
  • CDC health risk index: 10.72.

Who Supplies Your Water in Alamo

Residential water service in Alamo, CA is divided among 2 separate utilities, drawn from 2 systems on file with federal regulators.

EAST BAY MUD
Serves ~1,442,800 people
55
/100
CASA MEDANOS WATER SYSTEM
Serves ~45 people
55
/100

Overview

We track water quality and home safety data for 1 ZIP code in Alamo, California (population ~14,546), covering 2 community water systems serving approximately 1,442,845 people region-wide.

No EPA violations recorded across any ZIP codes in Alamo — an excellent indicator of water quality.

Home Safety Score

Average Home Safety Score for Alamo: C (55/100)

The score combines three factors:

Factor What It Measures
Water Quality EPA violations and compliance history
Lead Levels 90th percentile lead concentration vs EPA action level
Radon Risk EPA radon zone classification

Water Sources

Alamo water systems draw from: Groundwater.

Lead & Copper

  • Lead data: not yet available for Alamo
  • 0 ZIP codes exceed the EPA lead action level

Radon Risk

Dominant radon zone: Zone 2 (Moderate Risk)

The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.

Areas with No Violations

ZIP Code Safety Score System Population
94507 C EAST BAY MUD 1,442,800

All ZIP Codes in Alamo

Data Sources

Updated daily.

Health Outcomes in Alamo

9.4%
Asthma (US: 9.8%)
11.3%
Diabetes (US: 10.4%)
15.3%
Poor Mental Health (US: 14.8%)

Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.

Compared to National Average

Asthma 9.4% ↓
Diabetes 11.3% ↑
Mental Health 15.3% ↑

Vertical line = national average. Above national · Below national

Housing & Infrastructure in Alamo

1973
Median Build Year
66%
Built Before 1986
21%
Built Before 1970
Copper
Likely Pipe Material

With 66% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.

Source: U.S. Census Bureau American Community Survey (ACS).

Housing Age Profile

Federal plumbing rules changed in two stages — lead pipes were phased out before 1970, and lead solder was banned in 1986 — but in Alamo, where the median build year is 1973, most of the housing was already in place before those rules took effect. The materials installed under older standards remain embedded in a substantial portion of the residential inventory today.

1973
Median Year Built
66%
Pre-1986 (Lead Paint Risk)
21%
Pre-1970 (Lead Pipes Risk)
Pre-1970 (21%) 1970–1986 (45%) Post-1986 (34%)

Over half of homes in Alamo were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.

Source: U.S. Census Bureau ACS B25034.

Cost Context: What Remediation Means for Alamo Homeowners

Setting Alamo remediation figures against its property market, the resulting ratio sits comfortably in the low tier — a classification that reflects the kind of household financial position where most homeowners can identify documented issues, schedule the work, and absorb the cost without it registering as a significant budget disruption.

Median Home Value
$2.0M
Est. Remediation
$2,100
Remediation as % of home value 0.1%

Remediation costs in Alamo are relatively low compared to home values. The $1,100–$3,400 estimated range is a small fraction of median property value. Home values are 171% above the California average.

Lead Exposure Risk for Children in Alamo

66%
Homes Built Before 1986

Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.

Reading the local data together points toward a structural gap that matters more here than in low-exposure communities. 66% of Alamo stock comes from the pre-rule era, and citywide monitoring either approaches or sits beyond the federal benchmark under Lead and Copper Rule sampling. A baseline kit fits the routine-diligence category, with certified filtration available via retailer networks where confirmed faucet results warrant additional measures.

Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.

Flood & Climate Risk in Alamo

Flood history in Alamo spans 31 NFIP claims and 100% flood zone coverage — enough to place it in moderate-exposure territory where flood events are genuinely recurring rather than statistical outliers. That distinction matters for water quality assessment because the connection between flooding and water safety is not uniform across communities. In low-exposure areas, flooding rarely generates the conditions needed to compromise treatment or distribution infrastructure. In high-exposure areas, it can do so repeatedly. Moderate-exposure communities sit in between: flood events occur with enough frequency to make periodic infrastructure stress a reasonable concern, particularly for private well owners and residents in lower-elevation FEMA-designated zones.

31
Total FEMA Flood Claims
$5,158
Avg Claim Payout
100%
ZIPs in FEMA Flood Zones
~2
Est. Claims/Year

Alamo has a moderate flood history with 31 FEMA claims averaging $5,158 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.

How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$2,100</strong> remediation cost per household.

Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.

Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.

What You Can Do in Alamo

  1. Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
  2. Install a certified water filter. An NSF-certified pitcher or under-sink filter removes most common contaminants.
  3. Check your home's plumbing. With 66% of homes built before 1986, lead solder is a real possibility.

Frequently Asked Questions

Is the water safe to drink in Alamo, CA?
Alamo has an average water safety score of 55/100 (Grade C). No EPA violations on record. Check individual ZIP code reports for details specific to your neighborhood.
How does Alamo compare to California average?
Alamo has an average water safety score of 55/100, which is below the California state average of 73/100.
How many water systems serve Alamo?
Alamo is served by 2 public water systems across 1 ZIP code, serving approximately 14,546 people.
How much does it cost to fix water issues in Alamo?
Estimated remediation costs in Alamo average $2,100 per household, ranging from $1,100 to $3,400. Costs include filtration, pipe replacement, radon mitigation, and flood protection.
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