ont , ▁W ey er ha e user , ▁and ▁the ▁state ▁Department ▁of ▁E col ogy ▁began ▁de cont am ination ▁of ▁the ▁original ▁explos ives ▁plant ▁site ▁in ▁ 1 9 9 1 , ▁and ▁ultimately , ▁a ▁golf ▁course ▁was ▁built ▁where ▁the ▁plant ▁used ▁to ▁be . ▁Du P ont ▁has ▁recently ▁under g one ▁a ▁modern ▁transformation ▁as ▁the ▁modern ▁planned ▁community ▁of ▁" N orth west ▁Land ing " ▁has ▁been ▁realized . ▁The ▁city ▁is ▁expected ▁to ▁have ▁a ▁built - out ▁population ▁of ▁more ▁than ▁ 1 2 , 0 0 0 . ▁ ▁In ▁ 1 9 7 5 , ▁the ▁m idden ▁for ▁the ▁Se qual itch ew ▁Ar che ological ▁site ▁was ▁put ▁on ▁the ▁National ▁Register ▁of ▁Historic ▁Places ▁as ▁it ▁is ▁the ▁oldest ▁known ▁m idden ▁in ▁Washington ▁state . ▁ ▁Today ▁ ▁Today , ▁Du P ont ▁is ▁still ▁a ▁growing ▁community . ▁The ▁elementary ▁school ▁in ▁Du P ont ▁( Ch lo e ▁Clark ▁Element ary ), ▁which ▁hosted ▁kind erg arten ▁through ▁fifth ▁grade , ▁reached ▁capacity ▁in ▁the ▁ 2 0 0 7 – 2 0 0 8 ▁school ▁year . ▁As ▁a ▁result , ▁starting ▁with ▁the ▁ 2 0 0 8 – 2 0 0 9 ▁school ▁year , ▁Ste il aco om ▁School ▁district ▁real igned ▁all ▁three ▁elementary ▁schools . ▁Ch lo e ▁Clark ▁Element ary ▁and ▁Cher ry dale ▁Primary ▁in ▁Ste il aco om ▁now ▁only ▁have ▁students ▁in ▁gr