EXH0664024775

5B08 Lake Washington Blvd. N.E. Suite 200 KJrldand.WA 98033-7350 425,822-8880 • Fax: 425-889-S808 • www.parametrix.com DRAFT MEMORANDUM To: Keith Smith _ February 28, 2000 ' Background This memorandum provides a scope and budget for conducting range-finding Water-Effect Ratios (W'ERs) 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 only 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 WERs 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 conceaatration (LC50) is then deteimined for each water, and the two LC50s are compared to generate a WER: 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 * Genetic WQS = Site-speei.6c 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-speclfic water quality standard would be 9 ,g/L. Unlike a definitive _ study, exposure concenlrations in a range-finding WER study are not analytically verified, and the resulting LC50s…

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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 [...]