Sounds like they do a pretty good job of controlling the emissions. My primary concern, and this is a fairly uneducated concern, but I always envisioned a (bleak) future where we had already mined all the precious and rare-earth metals and minerals and were forced to use our garbage dumps to re-claim those materials. Of course a good recycling program, would in theory, prevent this from ever being necessary, but in general, burning stuff to create energy feels sooo 20th century, we should really be using renewables and nuclear.