Hi Jeanette.
Yes, he should be charged a DWM of some sort. Does the ‘vacant land’ charge also double as an availability charge, if so, then I suggest this would be the charge to change it to. If not then my understanding is that he is up for the whole charge this year, then you could discuss with your waste services area to introduce an availability charge for next year which would most likely be the same as the vacant land charge, if that is lower than the standard charge.
Hope this is of some assistance.
Glynes