EXH0238A018968

_e_-07-OO _2:55P northwesi: hy_rauli{ ¢ontU 206 439 24Z0 P.02 northwest hydraulic consultantssacramentoinc. 16300ch_Nmlen toad.Suite3S0 VaNCOUVer ..me,,._.,_Jn_:o._1u-_, s edmonton (20@241"6000"ohone (206}4]9-2420- fl_ seattle September 7, 2000 Mr. Ray Hel[wig ILegion_l DLrector Northwest ResJonal OfBce Waddn&,toa State Depa_xment of Ecology 3190- 160t.h Ave. SE Bellevue, WA 98008-5452 Subject: 401Cemficat.ion for Seattle-Tacoma International Airport. - Dear/Ca. HelIwig: Further to our meeting yesterday edtemoon, we would Liketo briefly summa.,ize the main findings to date of our review of the August 2000 "PrelJminL5,ComprehensiveStormwater Management PJ_n Seat'Je-Tacoma I.nternational Airport Master Plan Update Improvements" (SMP), Please note that we onlyreceivedourcopyofthefour-volumeSI_PonFridayAugust31 andtodatehaveonlymade a verypreli_naryand incompletereviewofthesedocuments.Furtherreviewcomments willbe forthcoming We understandthatEcology will bemaking aprelimina_ determinationtodayregarding theadequacy of the Port's subrmttals for making a decision on 401 Certification, and we are submitting these incomplete cornmemsfor your considerationhamakingthat determination. Also. we would like to recordourobjectionstoboththedelaym Ecologyprovidingcopiesof theSMP totheAirport Communities Co=die,onand to the tack of adequate time for us and others to provide review cozntT_r_ts. Our preliminary commentstodate are asfollows: 1. Anticipated impacts on base flows Volume 1." Section 6.2. ] - Predicted Baseflow Impacts Volume 4: Appendix F - Evaluation of Potential Base Flow Impacts Thereappeartobesignificantdiscrepanciesor inconsistenciesintheevaluationoftheproject'sbase flow impacts. It appearsthat the atudysispresented in Appendix F does not rely on the same hydrologicmodel ptrametessasusedelsewherein the SM:P.Most significantly, the baseflow impact a,'udysisappears:ohavereliedonhydrologicmodelparametersforthefillembanXmentwniclaare AR 018968 '_ _!_!E S_D " , R._D_,E/, ., -07'O0(THU! [c !7 +;063402524 F C03 0l:-C1-2_0_O_:22_e _:r:m-i_ELSEL"" ' ._V,.N 4Gl=',?-6an ; C;3/0_5 F-6211 Sap-07.00 12:B6P northwest hjtarauli¢ consu 206 439 2420 P.03 September 7,2000 oftheHSPI=modeltoac&ua/_embankmentrunoi_'daza.We haveattemptedtorepeattheanalysis presented LnAppendix 1_ using the…

Open full document

Upcoming Events

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 [...]