Post-fire aquatic monitoring network reaches consensus on thresholds for evaluating chemical exposure risks for aquatic life

A water-quality monitoring network that is tracking pollution from the Palisades and Eaton fires has reached consensus on which thresholds to use for evaluating how exposure to post-fire chemical contamination affects aquatic life – a key milestone in ongoing efforts to bring consistency to how individual monitoring partners use the network’s data to evaluate exposure risks.

The thresholds, which monitoring partners reached consensus on in September via a series of SCCWRP-facilitated deliberations, define the concentrations at which exposure to post-fire chemicals in different habitat types and different time periods begins to pose health risks for aquatic life. Because aquatic toxicity thresholds can vary based on multiple factors, federal, state and regional agencies were using different threshold values for the same chemical contaminant, leading to inconsistencies in how health risks were interpreted.

The aquatic health thresholds complement a set of thresholds for evaluating human health risks that monitoring partners reached consensus on in June.

Monitoring partners have begun uploading water-quality data into an open data portal being built by SCCWRP to support the Los Angeles-area Post-Fire Water Quality Monitoring Network in collecting, analyzing and visualizing data.