CITY REPORT CA

San Francisco, CA: Lead Above EPA Action Level - null

60 ZIP codes · 5 water systems · Updated

Data: EPA SDWIS, FEMA NFIP, Census ACS

60
ZIP Codes
5
Water Systems
0
ZIPs Linked to Systems with Violations
1
ZIPs Mapped to a System Above the Lead Action Level
Zone 2
County Radon Potential (Moderate)

Water Quality in San Francisco

We track home safety signals for 60 ZIP codes in San Francisco, California. EPA community-water data is directly mapped for 29 ZIP codes and 5 water systems.

The available EPA records report no violations across 29 directly mapped ZIP records with reported counts in San Francisco. This measured subset does not cover ZIP records without a confirmed EPA system mapping.

Water sources: Surface water.

Lead Risk

  • Average of reported 90th-percentile lead results: 0.0036 mg/L
  • 1 of 29 ZIP codes with known status exceed the EPA lead action level
  • 79% of housing built before 1986 (when lead solder was banned)
  • 50% of housing built before 1950 (when lead pipes were standard)
  • Median year built: 1936
  • Most common estimated pipe material: Galvanized Steel or Lead
  • Lead exposure risk score: 51/100
  • Estimated lead service line probability: 22%
  • 21 ZIP codes classified as high or very high lead risk

With 79% of homes built before the 1986 lead solder ban, San Francisco residents - especially those in older neighborhoods - should consider testing their tap water for lead. Homes built before 1950 are at the highest risk of having lead service lines.

Housing Age Distribution

408,198 total housing units across 60 ZIP codes:

Era Units Share
Pre-1940 187,143 46%
1940–1949 36,129 9%
1950–1959 32,935 8%
1960–1969 32,581 8%
1970–1979 29,202 7%
1980–1989 21,339 5%
1990–1999 16,836 4%
2000–2009 25,652 6%
2010–2019 24,815 6%
2020+ 1,566 0%

Flood Risk

FEMA National Flood Insurance Program data for San Francisco:

  • 145 flood insurance claims on record
  • $2,673,379 sum of reported building, contents, and ICC payment components
  • 104 claims with payment data
  • 41 claims without reported payment fields
  • $25,706 average reported component sum among claims with payment data
  • Dominant rated-zone value in historical claims: A (A/V-family)
  • 14 of 19 ZIP codes with claim-zone records have an A/V-family dominant rated zone in those claims
  • Claim-zone values are historical insurance records, not a complete current FEMA property-map inventory

Radon Risk

60 of 60 ZIP records with known zones are in EPA Radon Zone 2.

The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.

What San Francisco Residents Can Do

Test Your Water

  • Order a certified lab test - home test kits cost $20–50 and cover lead, bacteria, and common contaminants
  • Request your utility's CCR (Consumer Confidence Report) - your water provider must publish this annually
  • Check your ZIP code - each area in San Francisco has different water systems and risk levels

Filter Your Water

  • NSF-certified pitcher filter removes chlorine taste and some contaminants ($20–40)
  • NSF 53-certified filter for lead - recommended for homes built before 1986
  • Reverse osmosis system removes 95%+ of contaminants including lead, PFAS, and nitrates ($150–400)

Test for Radon

  • San Francisco is in a moderate-risk radon area
  • Short-term radon test kits cost $10–25
  • If levels exceed 4 pCi/L, EPA recommends professional mitigation

Stay Informed

All ZIP Codes in San Francisco

Frequently Asked Questions

Does San Francisco have lead in the water?

The average of the reported 90th-percentile lead results across the ZIP codes of San Francisco is 0.0036 mg/L, below the EPA action level of 0.015 mg/L. 1 of 29 ZIP codes with known action-level status are served by a system whose 90th-percentile lead result exceeded the EPA action level. About 79% of housing was built before 1986, when lead solder was banned.

Is San Francisco at risk for flooding?

FEMA data shows 145 flood insurance claim records in San Francisco ZIP codes, with an average reported building, contents, and ICC component sum of $25,706 among 104 claims with payment data. 41 claims lack reported payment fields and are not counted as zero. Among 19 ZIP codes with historical claim-zone values, 14 have an A/V-family dominant rated zone in those claims. Claim records do not establish current property-level flood risk; check the FEMA map for a specific address.

Are there lead pipes in San Francisco homes?

79% of San Francisco housing was built before 1986, when lead solder was common in plumbing. 50% was built before 1950, when lead pipes were standard. The most common estimated pipe material is Galvanized Steel or Lead. The estimated probability of lead service lines is 22%. We recommend testing your water if your home was built before 1986.

Data Sources

Source reporting periods vary. See each cited source for its publication schedule.

How Old Is San Francisco's Housing Stock?

1936
Median Build Year
Galvanized Steel or Lead
Likely Pipe Material

Median build year of 1936 means many homes predate lead paint and lead solder regulations. Consider testing if your home has original plumbing.

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

Housing Age Profile

1936
Median Year Built
N/A
Pre-1986 (lead solder era; lead paint banned 1978)
0%
Pre-1970 (Lead Pipes Risk)

Most homes in San Francisco were built after 1986; lead exposure at a tap still depends on its service line and plumbing. Older homes should still be tested.

Source: U.S. Census Bureau ACS B25034.

Protecting Children from Lead in San Francisco

1 of 60
ZIPs Mapped to a System Above the Lead Action Level
0.0036
mg/L average of reported water-system 90th-percentile lead results (the 0.015 action level applies to each system's result, not to this average)

Why children are most at risk: The CDC states that no safe blood lead level in children has been identified. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.

Available area-level lead records for San Francisco do not determine the lead level at an individual tap. Testing is the only way to confirm your water's lead content.

1 ZIP code (2% of the city's ZIP records) is served by a water system whose 90th-percentile lead result exceeds the EPA action level of 0.015 mg/L.

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

Historical Flood-Claim Evidence for San Francisco

145
Total FEMA Flood Claims
$25,706
Avg Reported Sum With Payment Data
74%
A/V Share of Claim-Record ZIPs

Historical NFIP data for San Francisco contains 145 flood insurance claims. Among claims with payment data, the average reported building, contents, and ICC component sum is $25,706. Among ZIP codes with claim records, 74% have an A- or V-family dominant rated zone recorded in those historical claims. This is not a complete current FEMA property-map inventory.

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.

Claim count does not establish current property risk. Check the exact address in FEMA's current map and obtain a property-specific insurance quote when relevant.

Source: historical FEMA National Flood Insurance Program (NFIP) claim records. No current FEMA property-map designation is asserted.

Deep Dive Reports

Detailed analysis for San Francisco, CA

Frequently Asked Questions

Does San Francisco water have lead?
The average of the reported 90th-percentile lead results across the ZIP codes of San Francisco is 0.0036 mg/L. The EPA action level of 0.015 mg/L applies to each water system's own 90th percentile, not to this average. EPA's health goal for lead is zero. Lead levels can vary by home - testing is recommended especially in older properties.
How many water systems serve San Francisco?
Our records map 5 water systems to 60 ZIP codes in San Francisco. The related population figure in our data is approximately 836,321 people; it is not a count of people served citywide.
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How to cite this page

APA ZipCheckup. (2026). San Francisco, CA: Lead Above EPA Action Level - null. https://zipcheckup.com/cities/ca/san-francisco/
BibTeX 
@misc{zipcheckup-cities-ca-san-francisco,
  author = {{ZipCheckup}},
  title  = {{San Francisco, CA: Lead Above EPA Action Level - null}},
  year   = {2026},
  url    = {https://zipcheckup.com/cities/ca/san-francisco/}
}

Page version: October 2026.

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