Monitoring effort underway in study examining how to update copper loading limits for streams

SCCWRP has begun collecting water-quality monitoring data on copper levels in Los Angeles-area streams to support an ongoing study examining the feasibility of using a toxicity analysis method known as the Biotic Ligand Model (BLM) to update stream copper loading limits.

The monitoring effort, launched in May and expected to last six months, will help fill in data gaps that researchers identified after inventorying historical water-quality data for copper from about 645 unique site-events over a 20-year period.

Collecting the data is a necessary precursor to using the BLM, which estimates how chemical characteristics of a water body influence the bioavailability and toxicity of metal contaminants such as copper.

The Los Angeles Regional Water Quality Control Board is interested in using the BLM to potentially update site-specific water-quality objectives for streams across the Los Angeles region. The BLM is an alternative to the established Water Effects Ratio toxicity analysis method.