Several years ago I lived outside the city limits of Tallahassee. Leon County had sattelite trash collection sites for residents to dispose items being discarded. They were similar to what is at the South Walton mosquito control office, except on a much larger scale. The problem with the mosguito control site is the hours of operation and not being open on the weekends. The Leon county sites were for residential use only, and accepted everything from household trash to used oil and batteries. There were several dumsters labeled for content, you could just bakup to and dispose your items. The sites were staffed by one person to ensure things were disposed in the proper container. They were open seven days a week from 9:00 am to 5:00pm. It was so easy to recycle as well as dispose of old mattresses and such. When I first started staying down here seveal years ago, Walton county had a similar site on county road 83, which is now used as a dirt stockpile area. I assume they shut the site down after we started recieving curbside pickup for household trash. Unfortunately everything other than household trash is not picked up and disposal can be a hassel. If only the mosquito control site had more accessible hours it would be great.
Mosquito Control is very helpful, when they are open. But they don't take everything you mention, like mattresses, old couches, etc. What we need is I think called a transfer station. Otherwise, you have to haul it to DeFuniak, or Freeport which is not free, or hire someone who can haul it for you. This is why the neighborhoods with dead end streets and lots of bushes and the state forest is full of trash and discarded goods.
Calling Waste Management for a bulk pick up is another option, but again, not free.
Many people in SoWal probably don't mind paying a reasonable fee to dispose of stuff, but some people don't have the means, and even if you do, it's a time waster or a gas waster, take your pick. And storing everything for the twice-yearly hazmat and then getting it to Mosquito Control on the right day is a time and space waster.
I can understand why people are tempted to illegally dump. Easier than figuring out what goes where and how to get it there.