LNAPL and Aquifer surfaces

[Kahn]

I have one more issue I am trying to figure out.  We want to show LNAPL overlaying the shallow aquifer so I created 2 "aquifers", one for product and one for groundwater.  However, when I model the LNAPL aquifer it has holes where the aquifer pinches out (see image below), which makes sense for groundwater but not for product.  Ideally, the product would appear more like bullseyes and not extend to the edge of the model area.  Do you know of a way to address this?  Thanks again for your help!