during water withdrawals. Impingement occurs when organisms are trapped against cooling water intake screens or racks by force of moving water. PNPS has been regularly monitoring I&E levels since 1974. They have reported I&E losses of millions of aquatic organisms each year. The EPA evaluated all species known to be impinged and entrained by the facility, including commercial, recreational, and forage fish species. Based on information provided in facility I&E monitoring reports, approximately 68 species have been identified in I&E collections since 1974, and 26 of these have commercial or recreational value. During the license renewal process, the Nuclear Regulatory Commission found that the significance of the potential environmental impacts of renewal would be small, with the exception of marine aquatic resources. Due to I&E, the continued operation of the cooling water system would rarely have impact on the local winter flounder (Pseudopleuronectes americanus) population, and the Jones River population of rainbow smelt, and cumulative impacts on other marine aquatic species would be small to moderate. After the aquatic organisms were impinged into the cooling system, they were discharged back into the bay as sediment. The resulting shadow effect killed plant and animal life around reactor discharge systems by curtailing the light and oxygen they need to survive; however, the intake and discharge canals remained a popular and lucrative local recreational fishing spot for local residents. Seismic risk The NRC's estimate of the yearly risk of an earthquake strong enough to cause core damage to the Pilgrim reactor was 1 in 14,493, according to their study published in August 2010, making it the second-most-at-risk plant when it was still operating. Notes External links DoE Page Entergy Nuclear Official Website of Pilgrim Power Station History of Pilgrim Power Station Energy infrastructure completed in 1972 Buildings and structures in Plymouth, Massachusetts Nuclear power plants in Massachusetts Entergy Former nuclear power stations in the United States 1972 establishments in Massachusetts 2019 disestablishments in Massachusetts