Water Effect Ratio Study

Abstract elegant, detailed blue glitter particles flow with shallow depth of field underwater. Holiday magic shimmering underwater space luxury background. Festive sparkles and lights. de-focused.

Our team supported the consulting firm contracted by the pulp and paper mill to determine if metal limits presented in the draft wastewater discharge permit were scientifically sound. The biggest concerns that needed to be addressed were the low limits for copper, cadmium, zinc, and lead, which would have been challenging for the discharger to meet.

EPA Approves California Statewide Toxicity Provisions

Farmers spraying pesticides in green fields.

In 2020 the California State Water Resources Control Board (SWRCB) adopted a State Policy for Water Quality Control: Toxicity Provisions (Provisions). Subsequently, the SWRCB sought approval of the Provisions from the US Environmental Protection Agency (EPA). On May 1, 2023, EPA Region IX officially approved the Provisions for use as a regulatory tool under the Clean Water Act (CWA)

Whole Effluent Toxicity Testing 101

Sediment, Elutriate, and soil roped off in farm land.

Whole Effluent Toxicity (WET) testing is a critical component of monitoring the health of aquatic ecosystems and it is included in many National Pollutant Discharge Elimination System (NPDES) permits. If your NPDES permit includes WET testing, it is important to understand why it exists and how to best implement it in order to save time, money, and other resources.