12,000 homes in 2007. Decommissioning The decommissioning project required significant oversight, because Marmot Dam was the largest concrete dam ever removed in the United States. PGE sought and received initial approval for the project from the Federal Energy Regulatory Commission (FERC) in 1999. PGE later employed RESOLVE, a non-profit dispute resolution organization, to help develop a detailed consensus plan among the interested parties. An agreement was reached in 2002 on the decommissioning. The primary issues addressed by the reviews were the impact on fish species (particularly salmonids), their habitat, and the effect of the release of 1 million cubic yards (750,000 cubic meters) of sediment on the river course. In 2004, PGE allowed its operating license to lapse, and filed a notice stating: "[...]the likely cost of providing the necessary level of protection, mitigation, and enhancement for the resources affected by the Project would outweigh the economic benefit of generation at the Project over the life of a new license[...]" The project continued to operate with license extensions while decommissioning awaited approval. In 2006, PGE requested special approval of the decommissioning from the National Marine Fisheries Service, because of the project's potential impact on coho salmon. The final review was conducted by the United States Army Corps of Engineers, which granted approval for the decommissioning on May 21, 2007. A spokesman for the Corps stated that the removal project was unusual, because "Large dams usually don't get removed." Before Marmot Dam could be removed, a temporary coffer dam had to be built upstream. When this phase of the project was complete, the removal of the permanent concrete dam could proceed. The destruction of the permanent dam began on 26 July 2007, when a public controlled demolition weakened the structure. The rest of the dam was destroyed using pneumatic hammers over approximately 4 months. The last concrete from Marmot Dam was removed on September 30, 2007, and the final phase of removal was completed on 20 October 2007, when the temporary earthen dam washed away and the Sandy River began to flow freely for the first time since 1912. PGE removed Little Sandy Dam in 2008, eliminating Roslyn Lake. This restored Little Sandy River flow and made salmon and steelhead migration once again possible. In May 2009, a fish biologist reported that salmon and steelhead were spawning upstream of the former dam. PGE donated of the dam site to the Western