On Tuesday, May 12, 2015 at 9:26:37 AM UTC-4, NorMinn wrote:

A lot we don't know here. Starting with, it's a townhouse,
which, in some cases, means it's a condo type arrangement
where the association has control over the outside stuff.
Regarding damaging the foundation, sure they could if the
trees are close enough that the roots can get there. From
the description, it's not clear what the distance is, but it
sounds kind of far.

Finally, removing tress roots like that is not an easy job.
I sure wouldn't want to have to do it, unless absolutely
necessary. As some have suggested, it may be easier to bring
in a load of topsoil, cover them up and plant a new lawn.
That may only be a temporary solution though, but it would
probably be many years before the problem resurfaces.