I buy bulk, which is often wet. I just hauled 6.5 tons in. My bin is apx 8' square, coal is at present time six feet deep [higher than in the pic below]. It was fresh from the breaker, and wet. Water has been seeping out of the bin for a week now, onto my boiler room floor. Like jrn, mine takes a long time to dry out. Some moisture is present for a long time. Although, I can't say that there is much odor, certainly not anything offensive.
Hindsight: A pipe [or two, or three] laying on the floor of bin, end sticking out through the boards holding the coal in the bin. Pipe or pipes would allow air to get back into the coal at floor level, speeding the drying process. Think the type of pipe designed to drain footers and such. Although, you could drill smaller sch 40, no need for 4". Fine screen clamped over the holes to prevent coal from getting into pipes.
If water on the floor is an issue, 90s could be stuck onto the ends of pipe or pipes where they 'daylight" to hold the water, and a shop vac could be used to pull said water out of the pipes until it stops.
Note: the water that drains from anth is normally nearly clear. Not black yuck water, like you would get from wet bit coal.
more fwiw, sealing any wood in the bin is a good thing imo. I use solvent based conrcete sealer to seal wood. ChemMasters, solvent base Polyseal, not water based polyseal [WB]. http://www.chemmasters.net/Cures-Seals.htm#Polyseal
Wood soaks it up well, and dirt and dust doesn't stick to the wood. The 2x4s are 20 years old, they were nasty from my years of burning bit. I pressure washed them and poured the poly seal to them when I "re-did" my bin when I went to anth. Even new wood soak it up pretty well. My point is, anything to make it easier to keep stuff clean = happier wife.
Here's a pic taken during my boiler install. The water runs out at the bottom, and under the sill into the boiler room. The "hindsight pipes" would stick through the boards at floor level. The bottom pic if from inside the bin room. Picture a pipe or pipes coming through the bottom board, possibly with wyes or a tees to the center, or even rear corners of bin. Such a setup would also allow some air to get into the bottom of the pile. I will probably do such a setup the next time my coal gets low.