Water from Lake Pend Oreille could be used to recharge the region’s drinking water supply, but it’s a costly option, a new study concludes. The study looked at capturing spring flows from Lake Pend Oreille by drilling wells at the lake’s southern tip. The water would be pumped back into ground at other locations to recharge the Spokane Valley/Rathdrum Prairie Aquifer, which is the sole source of drinking water for nearly 600,000 of the region’s residents.