Option 1- Do nothing.

Option 2- Call Cops. That is going to go about nowhere quick unless you include the driving etc. Even then, the tension between you two may not be worth it.

Option 3- Why not print out the statute, highlight the areas of concern and have it delivered. They just might "get it" and conduct themselves in a different manor.

My neighbor smokes outside in his back yard. I get a good mess of smoke coming my way a lot. I don't like it either, but I am not going to risk a 10 year good relationship over a bowl of weed.