This laboratory group monitors the impact of wastewater effluent on receiving waters by means of the following activities:

• Performing acute and chronic bioassays on treatment plant effluents and receiving waters using standard toxicity test procedures developed by the EPA.
• Making toxicity reduction/identification evaluations as necessary.
• Logging monthly observations at receiving water stations to regularly assess environmental conditions and activities.
• Conducting bioassessment surveys in the San Gabriel, Rio Hondo, and Santa Clara River watersheds. This involves the collection of benthic macroinvertebrates (BMIs), physical habitat observations, and flow measurements.
• Performing bioassays for research including experimental treatment plant processes, interpretation techniques for toxicity data, and developing methods for identifying toxic constituents in water samples.