I wonder if the solution here is entirely different. Maybe instead of asking what-ifs per-se we ask, "well, why would someone not do it the proper way." The answer there is, whether justified or not, the current process is too much of a "hassle" (I don't see it as such but for someone dumping motor oil down storm drains for them it apparently is). We can't make them do the current process that is more of a "hassle." So how do we make a more "hassle-free" process? Maybe like garbage, one Wednesday a month, the recycling/garbage company picks up jugs of fluids? We have an existing process, so maybe we just rope one more thing into. The county/city already does garbage pickup and disposal, why not fluids?