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Altadena Testing Reveals Ongoing Lead & Asbestos Risks

By December 4, 2025 No Comments

Post-Fire “Cleanup” Falls Short: Altadena Testing Reveals Ongoing Lead & Asbestos Risks

A recent Los Angeles Times investigation has identified a critical gap in wildfire recovery practices: many Altadena homes that survived the Eaton Fire remain contaminated with hazardous levels of lead and asbestos despite undergoing professional cleanup. For environmental professionals, these findings highlight an emerging due-diligence challenge as wildfire smoke and ash become more common contamination pathways.

What Testing Found

Post-remediation sampling revealed that:

  • Lead dust persisted in nearly all homes tested, with many exceeding typical residential clearance thresholds.

  • Asbestos fibers were detected in roughly one-third of tested homes, despite having been “cleaned.”

  • Several homes passed initial cleanup programs but later failed laboratory wipe and dust tests, raising questions about the adequacy of standard post-fire remediation protocols.

In short: a structure can be declared cleaned, yet still pose significant exposure risk.

Why Contamination Remains

Wildfire smoke and ash can mobilize legacy materials—lead-based paint, asbestos-containing building materials, metals, and PAHs. These particulates infiltrate indoor spaces and become embedded in porous surfaces where basic ash removal or HEPA vacuuming does not achieve full clearance. Many cleanup programs also do not include post-remediation verification sampling, leaving residual hazards undetected.

Implications for Environmental Due Diligence

For those involved in Phase I ESAs, Phase II investigations, underwriting, or redevelopment planning, these findings underscore several key considerations:

  • Indoor lead/asbestos deposition in wildfire-impacted areas may constitute a Recognized Environmental Condition (REC) under ASTM E1527-21.

  • Supplemental indoor dust or air sampling may be warranted, even when a property has already undergone cleanup.

  • Failing to identify residual contamination can create long-term liability for property owners, managers, and public agencies.

  • Re-occupancy decisions should increasingly rely on quantitative clearance data, not visual inspection or cleanup completion notes alone.

How McAlister GeoScience Supports Fire-Affected Sites

Our team provides wildfire-focused environmental services including:

  • Indoor lead/asbestos wipe sampling

  • Post-remediation verification testing

  • Ash, soil, and particulate sampling

  • Phase I/Phase II assessments for fire-impacted properties

  • Remediation planning and regulatory coordination

  • Vapor intrusion and air quality evaluations when combustion residues indicate potential volatile contaminants

With the integration of the Orswell & Kasman proprietary database, we also offer enhanced historical records research to support more accurate risk evaluations in wildfire-prone areas.

Takeaway

The Altadena results make one point clear: surviving a wildfire is not the same as being safe from contamination. For due-diligence teams, lenders, and environmental consultants, a more rigorous, sampling-driven approach is now essential for fire-impacted structures.

If you are evaluating a property affected by wildfire or need guidance on appropriate sampling scopes, McAlister GeoScience can help ensure your conclusions are defensible and aligned with current environmental risk realities.

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