BillS, you're right - the 10D was for power loss considerations, the turbulence was just a guess based on that.
the airport's proposal's at
http://www.eastmidlandsairport.com/d...ne-handout.pdf
shows 31.5 as hub height, 45m ground to blade tip. looking at the location, i'd guess they're unlikely to cause turbulence problems in a southwesterly, given the hangars to the northeast. but there appears to be nothing between them and the western end of the runway (17 diameters away), so in a southerly/southeastery wind it would depend on how far the turbulence lasts downstream.