in California you can advertise to buy your own properties and do not have to disclose you're an agent when doing that, I've confirmed this with CAR legal.  

I bought a aux cord from the local gas station so I could listen to them in the car.

I don't think the guys working at the tacqueria around the corner are moonlighting as tech engineers.

Car? 

And of course solvents from cleaning up cars and parts.The problem is that with heavy ran, all those chemicals tend to rise up out of the water-soaked ground and run off into the area.As an aviation side note, it used to be common that small airplane pilots would use fuel testers on their gas tanks by sumping a little fuel from the wing tanks to check for water contamination.

D-/F is the active gang presence, chrome rimmed cars driving around constantly area.

(The student could still be on parent(s)' car insurance and healthcare plans.) 

The idea is to minimize risk wherever possible and we civil engineers specialize in recognizing risk because we've been screwed by every rule you can imagine.

Maybe the house has a pool or a two car garage vs. one.  

A lot of young lawyers, teachers, engineers, etc.