I have often wondered about wake turbulence away from the immediate runway. In Los Angeles some heavy commercial traffic inbound route over the SMO VOR fly downwind east to downtown LA, turn base south towards Long Beach and final back towards the LAX, there is a VFR route directly below the base leg that tracks the LA river (the schwartznegger one) with an altitude restriction of 1700 if I remember correctly, however the CAT turning final appear no more that 2000ft above the transiting GA . What is the safe vertical clearance to allow WT to dissipate in a no wind situation from slow and heavy CAT? I read a story in Canada I believe where a GA transiting a terminal area was vectored below a jet and had a in flight break up due to WT.