Study examining how to use Biotic Ligand Model to update copper loading limits in freshwater systems

SCCWRP has launched a study examining the feasibility of using a toxicity modeling tool known as the Biotic Ligand Model (BLM) to update copper loading limits for freshwater systems across the Los Angeles region.

The study, launched in December with the Los Angeles Regional Water Quality Control Board, will evaluate whether sufficient data already exist to support use of the freshwater BLM. The BLM, which is an alternative to the established Water Effects Ratio (WER) toxicity analysis method, estimates how chemical characteristics of a water body and their interaction with biological communities influence the bioavailability of metal contaminants.

The U.S. Environmental Protection Agency has endorsed using the BLM to develop site-specific criteria for copper contamination in freshwater systems.

For the study, SCCWRP has compiled a database with more than 30,000 data points from about 50 projects over the past two decades. Researchers also will investigate the feasibility of getting additional data points needed for BLM analyses by leveraging existing monitoring efforts in the L.A. region.