Is the advocate for your spanish-speaking tenants not concerned with the illegal TENANTS you have in your park? It appears that you have more than one problem that you need to deal with. The illegal immigrant issue is huge right now, and some areas are targeting landlords for allowing them to live in their homes.
I would suggest that you get a police officer presence in your park, which would cut down on the volume of drugs being sold there. Unfortunately, it is not uncommon to find a park with this type of activity. Go to your local police department and hire an off-duty cop (with vehicle) to sit at the entrance to your park! (We are lucky that we actually have an officer who lives in the park we just purchased, and he has assured us that that type of activity has already moved on!)
This presence might, however, make your illegal tenants nervous. You might want to find out more about that issue…I understand the illegal immigrants actually are very good about paying their rent, etc. because they do not want any authorities notified that they are even there, so you should not have issues with getting their money. The question is, do you want their money or would you rather have tenants who are legal. (Spanish-speaking or otherwise!) If the immigration authorities came to your park and you had many illegal immigrant tenants, I would assume they could all be arrested and you would then have no money coming in. If you only have one or two, perhaps the issue is different.