Ace Pelizon Plumbing was called out on a dishwasher backing up under the sink. Ace Pelizon Plumbing found air gap mounted under counter behind sink. Leak coming from air gap and and basket strainer connection. Removed air gap from underneath sink. Found that dishwasher drain line already has anti-siphon loop mounted to wall. Recommend to customer that airgap hole is drilled in sink deck and air gap installed in the future. Cleaned garbage disposal dishwasher port that was clogged with sludge. Connected dishwasher drain line and tested appliance while on site. No back up at this time. Tighten existing basket strainer and verified no leak coming from under sink at this time,