Complex sentence: One year later, the Wild Zoo solved its problem of wastewater discharging into the rivière-aux-saumons in September 1993, by using artificial swamps to treat waste coming from the zoo and the campground before entering the rivière-aux-saumons.
Split into simpler sentences: One year later, the Wild Zoo solved its wastewater problem that was discharging into the rivière-aux-saumons in September 1993. The Wild Zoo would use artificial swamps to treat the wastewater that came from the zoo and the campground before it entered into the rivière-aux-saumons.