Notes
Draft memorandum dated April 25, 2000 (drafted April 20, 2000), AR026666, from Doug Henderson and Linda Logan (project number 556-2912-001(61)) to Port Of Seattle project files, summarizing range-finding toxicity test results for water-effect ratio (WER) study for copper in streams receiving Seattle-Tacoma International Airport (STIA) stormwater. Tests conducted April 15–17, 2000 using Daphnia magna acute toxicity tests on site water samples from Miller Creek Upstream, Miller Creek Detention Facility, Northwest Ponds Outlet, Northwest Ponds Inlet, and Des Moines Creek Weir. Copper spiked using copper sulfate pentahydrate (CuSO4·5H2O, CAS#7758-99-8), 500 mg/L stock solution verified by Battelle. WER calculated as LC50 Site Water divided by LC50 Laboratory Water; nominal test concentrations used (not measured). Samples collected by Taylor Associates using ISCO flow-weighted composite samplers during qualifying storm event. Analysis conducted at Parametrix toxicology laboratory per EPA/600/4-90/027F August 1993. Related to PCHB third-runway EIS proceedings.