PCHB103003158

This memo is to describe the results of the Reasonable Potential Analysis (P,PA) that was performed yesterday for the STIA Third Runway area. The analysis was done in a working meeting attended by Lisa Zirmer (Ecology), Loft Terry (Preston, Gates, and Ellis), Tom Hubbard (POS), John Rogers (CH2M Hill), Bill Taylor (Taylor and Assoc.), Jim Good, and myself. Lisa Zinner stated at the beginning of the meeting that the analysis was intended to be informal. Some of the data used was based on best available information and professional judgment reached by consensus. The attached spreadsheet documents the process, which was performed in steps: 1. Data from outfall 005 (SDS-3) was used to represent the predicted runoff from the Third Runway (with two 1996 deicing sampling events removed from the data set). The geometric 95th percentile of the SDS-3 data was calculated as per the R.PA methods. This was done by calculating the natural log of each parameter's reported value, taking the 95th percentile of the transformed values, then taking the antilog of that value. 2. The criteria for MiUer Creek and Des Moines Creek were determined, based on background condition and hardness information. The fecal coliform criterion is the limit set for all class AA waters. The turbidity criterion is based on observations made in Miller Creek during winter 1997-98 storms, for NEPL treatment plant and Lake Reba discharge monitoring (to be verified upon review of the data). The metals criteria were based on a hardness of 23 ppm in…

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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 [...]