EXH0663024773

5808 Lake Was_ingzonBIv_ N.E Suite 200 KirKland,WA98033-'7350 425-822..8880 • Fax: 425-889-8808 MEMORANDUM To: Scott Tobiason /j Scptcmber 20, 1999 • From: Ken Ludwa, Patti Fendt, Lin 55-2912-01 (61) Re: Review of 1999 Annual Stormwatcr Report We have reviewed the first draft of the 1999 Annual Stormwatcr 1_cport. In addition to the handwritten margin comments that are attached to this memo, please consider the following COmments: * Consider adding more description of the Portland NPDES study, particularly why it is relevant and comparable to STIA data. Unless this study is more comparable for other parameters as well, you may wish to reconsider changing the eomparator for only copper. - Particularly, the report states initially (page I0) that the instr_am Bellevue samples are used for a conservative comparator, but for copper (page 18) the Portland (ouffall) study was useA. Because the comparators by their nature are arbitrary, they should be consistent between years and between parameters. • "Trimmed" da_ sets are discussed several times. The methods section should explain the statistical validity of this procedure. Is there a more formal statistical term for this procedure? • Although TSS concentrations and turbidity decreased after the addition of the cons_ction wheel wash, other factors may have also attributed to the decrease: i • Other BMPs also became effective; for example, grass germinated after the first rains. _ Some disturbed soil surfaces may have also "settled" after the first few storms. * New SDS pipes were installed for the taxiway work; some soil in the…

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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 [...]