Complex sentence: The largest known site with the most HAZWOPER trained personnel is the Hanford Site in Washington it is approximentally 500 square miles clean-up and reclaimation activities continue to this day.
Split into simpler sentences: The largest known site with the most HAZWOPER trained personnel is Hanford, Washington. The site is approximentally 500 square miles and clean-up and reclamation activities continue to this day.