EXH0727026502

This letter is to report the fourth quarterly stormwatermonitoringresults for the Seattle- TacomaInternationalAirportNorthEmployees' Parking Lot (NEPL),per Condition7 of the InterlocalAgreement(ILA) between Port of Seattleand City of SeattlePublic Utilities. As with the three pr6vio-ussamples,stormwaterwas collected at the outletof the bioswale from the stormwaterdetentionvault. Rainfall for theday totaled0.68 inches. The samplewas a flow-weightedcompositeand was analyzedby AquaticResearch, Inc. LaboratoryQA/QC data were withinacceptablelimits. The results from this and previous quarters are reported below, along with residentialwatersupply criteria. The raw data from the laboratoryis attached. North Employees' Parking Lot stormwater analytical results for January 14, February 22, May 15, and October 8, 1999 and Washington State residential water supply criteria. All units are mg/L. Observed Observed Observed Observed Residential Value Value Value Value Water Parameter Jan. 14, Feb. 22, May 15, Oct. 8, Supply 1999 1999 1999: 1999 Criterion I TotalSuspendedSolids (TSS) 5.60 9.8 12 2.3 Tot Petro. Hydrocarbons (TPH) 0.54 0.18 0.32 <0.10 pH 6.4 8.2 meterfailed 7. l - Total Cadmium <0.00020 <0.00020 <0.00020 <0.00020 5.0 Total Copper <0.0020 <0.0020 0.0118 0.0070 1.0 Total Lead <0.0020 <0.0020 <0.0020 <0.0020 15.0 Total Zinc 0.049 0.038 0.124 0.102 5.0 Residential criteria are a Primary State Standard for cadmium, Residential Action Level for lead, and Secondary State Standard for copper and zinc. TPH sample was taken on June 2 I, 1999. Forthis 4_ sample, total recoverablemetalconcentrationswere severalorders of magnitude less than residentialwater supply criteria. Cadmiumand lead concentrations were less than the laboratory detectionlimit. The TPH concentrationwas also less than the laboratory detectionlimit. Copper and zinc concentrations,as…

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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 [...]