PA-32 Cherokee Six/Lance/Saratoga/6X
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 10
Communication Breakdown; Situational Awareness; Confusion
ATC Issue All Types; Conflict Airborne Conflict
Air Traffic Control Issued Advisory / Alert
Airspace Structure; Aircraft; Human Factors; Procedure
I released Aircraft X off of LGB Runway 30. By the time LGB tower departed the aircraft; there was a VFR aircraft within their Class D tracking south towards the departure corridor at 1;700 feet. When Aircraft X became airborne I reached out to him when I didn't get an immediate check-in. That is when Aircraft X checked in and I issued an expedited climb since he was converging the VFR target at 1;700 feet. When I noticed the VFR aircraft altitude appear to climb to 1;800 feet; I issued a 250 heading to Aircraft X to get him away from the unverified target. After Aircraft X was a safe proximity away from the VFR traffic; I asked him if LGB Tower had told him about the traffic. He said they had and that they were told the traffic was going to go behind him. I explained to him that this wasn't the case because they were in-fact converging.This is a common occurrence with LGB Tower. We will release an aircraft from LGB; which at the time the airspace is clean. By the time the aircraft gets airborne; there's usually a conflict to which we have to take evasive action to miss. This is because the Tower just gives a traffic advisory; clears the aircraft for departure; and then issue a frequency change without ensuring separation. My recommendations is to retrain LGB Tower on how to ensure separation of aircraft in their Class D and decrease the amount of time LGB has to depart aircraft (I think right now they have a 4 minute window).
SCT TRACON Controller reported an NMAC with an IFR departure off of Long Beach and a VFR aircraft within the LGB Class Delta airspace.