Storing coal

So I am going to be purchasing a wl110 in the future and I am thinking about my coal storage. I plan to have the boiler by the end of this heating season, so I will be able to play with it in the summer and get used to it. I plan on building either a 4x4x8 or a 4x4x10 bin that will sit right along my driveway for my bulk storage, but until then would it be okay to just have it dumped in my driveway on a tarp and covered?

Here is my idea for my bulk coal storage bin, it would have removable b…