Is Firefighting Water from Battery Fires Hazardous?

Exponent summarized peer-reviewed and gray literature for data characterizing the concentrations of inorganic and organic contaminants in firefighting water from BESS facilities and battery electric vehicle fires.

We reviewed sampling and analysis plans and water chemistry results from new battery burn tests for a range of battery module types and chemistries.

Leveraging expertise from Exponent's Thermal Sciences and Polymer Science & Materials Chemistry practices, our team developed a model that scaled firefighting response to the size and type of BESS facility based on published National Fire Protection Association standards. 

Based on user input to the model, we scaled water quality data for firefighting water from the laboratory level to whole or partial BESS unit fires.

We created a screening model simulating the fate and transport of metals to soil, groundwater, and surface water (Figure 1). The model estimated infiltration and accounted for advection and dispersion of inorganic constituents in groundwater flow with increasing distance from the BESS facility. 

Figure 1. Conceptual model of the fate and transport pathways of metals and other contaminants contained in BESS firefighting water.

We simulated thousands of potential scenarios with varying BESS specifications and soil types and compared the simulated soil, groundwater, and surface water concentrations with U.S. federal human health and ecological screening levels. Exponent's analysis allows the model user to evaluate how site-specific factors may drive potential impacts, such as how soil physical parameters and adjacent land use affect infiltration and subsequent transport of constituents to groundwater and surface water. For example, high-infiltration soils and land-uses have higher groundwater concentrations than low-infiltration soils, but lower or no migration of metals to surface water bodies.