RoundUp is not a problem when used correctly. The problem is that most people have no idea how or when to properly apply it.
We install the finest meadows on the planet for some very seriously organic clients. No other designer can touch us or match our work. Basically, we have no competition at our level - we stand alone. We have done meadows from North America to South, from Spain to Switzerland to Dubai.
One of the most difficult parts of the process is when we have to explain why we use RoundUp and that - when properly applied - there will be no residual effect. The only thing it hurts is the plant material that we want to get rid of. It won't run off or permeate if used responsibly.
The whole trick is to apply it to growing flora. When we are doing a total project (covering everything in meadow grasses) we actually fertilize and water the hell out of the existing plant material during the growing season. When we are sure that growth is happening, we hit it with RoundUp.
Unfortunately, too many times RU is applied to dormant material.