Flying Feild R.I.P.
Philip,
The Northeast Aero R/C Club up in Monroe had the same problem, and found the same solution. They now fly off of a capped landfill.
I was a charter member of that club when it formed in 1988, but I've been away for 11 years. One of the founders, who actually got the land-fill deal going, was Jim Butler. He died a while back, but there may be somebody there who remembers what was done.
Steve