EXH0635024619

5808 /_ke Washington BIvQ, N.E. Suite 200 Kirklan_3, WA gs033-T350 425-822-8880 ° Fax: 425-889-8808 • www.l_arametrix,com p ._. : DRAFT MEMORANDUM To: Keith Smith February 28, 2000 From: Doug Henderson / Linclz Logan 556-2912-001 (61) Subject: Range-Finding WEtLs Background Thismemorandum pro_ddes a scope and budget for conducting range-finding Water-Effect Ratios (WEKs) using just receiving water from Miller and Des Moines Creeks. Recall that such testing is necessary in the event that the Port is not granted a mixing zone. The budget ordy includes costs associated with conducting the tests, and does not include - additional consulting time that may be required (e.g., meetings with the Port or with DOE or responding to Port comments). The objective of the range-finding WElLs is to determine if the final WERs would be robust enough to warrant the expense of conducting definitive studies, The range-finding studies consist of concurrent acute toxicity tests with copper- spiked site water and copper-spiked laboratory water. A median lethal concentration (LC50) is then determined for each water, and the two LC50s are compared to generate a WEK: LC50 Site Water =WER LC50 Laboratory Water The WER is then applied to the generic water quality standard to derive a site-specific standard= WER * Generic WQS = Site-specific WQS For example, if the water quality standard for a chemical is 3 _tg/L, and a WER of 3 is derived for a particular site, the resulting site-specific water quality standard would be 9 _tg/L. Unlike a definitive WE,R study, exposure concentrationsm a…

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PSCAA Advisory Council Meeting Agenda
Add to CalendarMWednesday Mar 11, 9:00am - 11:35am
1904 3rd Avenue, Suite 105, Seattle, WA 98101
Call to order – Roll Call – Quorum Established – Land Acknowledgement We would like to acknowledge that our Agency operates in four present-day counties, which are the traditional lands of the Coast Salish people, past and present. This acknowledgement does not take the place of authentic relationships with indigenous communities in our jurisdiction and [...]