Posted on

EXH AR024993: Site-Specific Water Quality Standard WER Study Process Flowchart

Document Library
Sea-Tac Airport
Third Runway
PCHB
Box 10

This document outlines the Port of Seattle's step-by-step process for applying water quality standards at a specific site, focusing on copper toxicity testing in local waterways. The flowchart guides researchers through a series of studies — including screening, range-finding, and definitive toxicity tests using waterfleas and fathead minnows — to determine whether copper levels in outfall and receiving waters pose environmental risks. Depending on test results and regulatory approval from the Washington State Department of Ecology, the process may lead to a Water Effect Ratio (WER) study or a Translator Study.

Open full document

Notes

Exhibit AR024993 from the PCHB Third Runway EIS administrative record. Parametrix, Inc. flowchart depicting the Port Of Seattle site-specific process for applying the Water Quality Standard via Water Effect Ratio (WER) studies for copper. Diagram shows sequential decision steps: WER Screening Toxicity Study (testing outfall and receiving water mixtures using waterflea), WER Range Finding Study (bioassays across copper concentrations, no analytical chemistry, waterflea), WER Work Plan, Ecology Approval, WER Definitive Study (range of copper concentrations, analytical chemistry, waterflea and fathead minnow), and Conductor Translator Study. Decision nodes include toxicity presence/absence and favorable/unfavorable results.

Sidebar On/Off
V V