Understanding PFAS Fate in Landfill Leachate Evaporation Systems

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Why PFAS in Landfill Leachate Matters

Per- and polyfluoroalkyl substances (PFAS) are a growing focus in environmental compliance programs for industries managing wastewater, residuals, and solid waste streams. Municipal solid waste (MSW) landfills receive PFAS-containing materials from a wide range of consumer, industrial, and commercial products, creating challenges for leachate management, environmental monitoring, and regulatory compliance.

At the same time, landfills need dependable ways to manage leachate volumes on site. Transporting leachate for off-site disposal can create cost, capacity, logistics, and planning challenges. Leachate evaporation systems are intended to address that operational need by reducing liquid volume while concentrating residual solids for managed return to the landfill waste mass or other approved management pathways.

The environmental question is whether evaporation transfers PFAS to air emissions at levels that could affect the surrounding environment. The testing summarized here was designed to help answer that question using real operating data.

How Leachate Evaporation Reduces On-Site Liquid Volume

APTIM's E-Vap® system evaporates the liquid fraction of leachate and produces a high-solids residual stream. Reported operating data identified residual volume at less than 10 percent of influent volume under the tested conditions, depending on incoming leachate total solids content. This corresponds to greater than 90 percent liquid volume reduction.

For landfill operators, this volume reduction can reduce reliance on off-site liquid management and provide a controlled, on-site treatment pathway. For the technology to be viable, volume reduction must be paired with environmental performance data addressing particulate matter, PFAS fate, and modeled air impacts.

The testing program therefore evaluated both operational performance and environmental safeguards: particulate emissions with and without a pilot venturi scrubber, PFAS constituents in the exhaust stream, PFAS distribution among leachate, residual, and stack streams, and modeled ambient air impacts.

Testing Objectives: Particulate Matter, PFAS & Scrubber Performance

The testing evaluated whether a wet venturi scrubber reduced filterable, condensable, and total particulate matter in the E-Vap® exhaust stream. It also evaluated which PFAS constituents were present in the exhaust stream and how measured PFAS concentrations differed with and without the scrubber.

Together, these comparisons distinguish the incremental control provided by the scrubber from the modeled air impacts of the base evaporation process. The unscrubbed results establish the baseline for assessing whether the base evaporation process, before additional scrubber control, produced modeled PFAS concentrations approaching comparable state-level ambient criteria.

What Testing Reveals About Environmental Performance

Testing evaluated filterable particulate matter, condensable particulate matter, total particulate matter, and 48 individual PFAS compounds using a modified version of the US Environmental Protection Agency's (EPA) Other Test Method (OTM-48). The results showed that the venturi scrubber reduced particulate emissions from the evaporator exhaust stream.

Filterable particulate removal efficiencies ranged from approximately 61 percent to 82 percent, while total particulate removal ranged from approximately 57 percent to 77 percent, depending on operating conditions.

PFAS testing also showed lower concentrations of certain constituents in the scrubbed exhaust stream. Measured stack concentrations indicated approximate reductions of 94 percent for perfluorooctane sulfonate (PFOS) and 97 percent for perfluorooctanoic acid (PFOA). These results suggest that the scrubber can further reduce exhaust-stream PFAS by capturing particulate-bound material.

The assessment did not rely solely on scrubber performance. The unscrubbed E-Vap® exhaust stream was also evaluated through air dispersion modeling. When PFAS constituents detected in the unscrubbed exhaust were summed and modeled as total PFAS, the maximum modeled ambient concentrations were generally below comparable state-level PFAS air standards and guidance values evaluated.

For context, the modeled 24-hour total PFAS concentration from the unscrubbed E-Vap® stack emissions was 0.000679 µg/m³, compared with the New Hampshire 24-hour ambient air limit for PFOA of 0.05 µg/m³. In this screening comparison, the modeled total PFAS concentration was approximately 74 times lower than the comparable state ambient air limit.

PFAS distribution results indicated that most identified compounds remained in the evaporator residual, which was returned to the landfill waste mass under the tested operating approach.

Interpreting Volume Reduction & Modeled PFAS Air Impacts

Taken together, the results support the conclusion that leachate evaporation can be a viable means of managing on-site volume reduction without creating modeled PFAS ambient air impacts approaching the comparable state-level criteria evaluated. The system reduced liquid volume, most identified PFAS constituents remained in the residual stream, and modeled total PFAS concentrations from the unscrubbed exhaust were below comparable ambient air limits and guidance values.

The venturi scrubber adds another layer of emissions-control capability. It reduced particulate matter and reduced measured concentrations of certain PFAS constituents in the exhaust stream. That is valuable for facilities seeking additional control or conservative permitting support, but the testing also shows that the unscrubbed exhaust modeled below the current comparable state-level ambient thresholds reviewed.

For landfill operators, on-site leachate evaporation is more than a volume-reduction tool. When properly evaluated, tested, modeled, and managed, it can be part of a responsible leachate management strategy that supports operations while maintaining environmental performance.

Integrating PFAS Compliance into Landfill Leachate Management

Landfill operators are evaluating how PFAS leachate treatment systems align with environmental compliance obligations, performance goals, and risk management strategies. Leachate evaporation intersects with multiple considerations, including air emissions compliance and permitting, wastewater and leachate treatment requirements, residuals management, PFAS monitoring and reporting obligations, and environmental liability management.

The testing results help support a more complete understanding of the E-Vap® system's performance by evaluating both emissions-control effectiveness and modeled ambient impacts. This provides practical information for owners, operators, engineers, and regulators assessing whether controlled on-site evaporation can be used responsibly as part of a leachate management strategy.

Applying PFAS Test Results to Site-Specific Leachate Decisions

The solid waste industry continues to evaluate how PFAS move through landfill systems, leachate treatment technologies, residuals streams, and environmental pathways. Treatment evaluations, emissions testing, PFAS analytical testing, air modeling, and environmental monitoring remain central to site-specific PFAS management.

For leachate evaporation systems, the testing described here reinforces several findings: PFAS were present in the leachate; most identified PFAS constituents generally remained in the evaporator residual; the system supported significant on-site liquid volume reduction; the venturi scrubber reduced particulate emissions and certain PFAS constituents in the exhaust stream; and modeled ambient PFAS concentrations from the unscrubbed exhaust stream were below comparable current state-level ambient air limits and guidance values.

Together, these findings indicate that leachate evaporation can support reliable on-site volume reduction while maintaining an environmental profile that, based on the tested conditions and modeled results, does not indicate negative ambient air impacts from PFAS emissions.

How APTIM Supports PFAS & Landfill Leachate Management

APTIM provides landfill engineering, PFAS consulting, leachate treatment evaluation, air emissions testing, environmental monitoring, and solid waste compliance services to support clients managing environmental and operational requirements.

Our teams investigate and characterize PFAS, evaluate treatment systems, model and test emissions, optimize leachate management, assist with permitting, monitor environmental conditions, and plan infrastructure.

Connect with APTIM's solid waste and PFAS experts to evaluate leachate evaporation, emissions controls, residuals management, and permitting needs for your facility.

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Published August 2026

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