Document: NRC Regulatory Guide
Document ID: e5306f4f-dc8c-4f60-a71c-af7ad4080384
Document Type: regulatory_guide
Title: Aquatic Environmental Studies for Nuclear Power Stations + HISTORY - HISTORY 12/2014 – DG-4023 -Proposed New Guide
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML1318/ML13186A085.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.24
CFR Part: 
CFR Title: 

Content:
leted early enough to support anticipated impact analyses and monitoring that federal and state agencies might require. These investigations may be prepared as separate reports or presented as part of larger documents such as environment reports. Analysts can combine closely related baseline studies and analyses into single reports. 4. Analysts should label aquatic habitats on maps using standardized or commonly used regional nomenclature when possible. They should describe substrate type, salinity range, tidal range, and dominant benthic and pelagic communities, as applicable. 5. Aquatic environmental impact analyses should focus primarily on species and habitats meeting NRC importance criteria (Ref. 26) in addition to water availability, current patterns, river flow, tidal flow, and effects of intake and discharge building and operation. Specialists may need to conduct site visits at specific times of the year to determine whether important species are present and, if so, are subject to impact. 6. Analysts should quantify habitat modifications and losses by overlaying the estimated limits of disturbance over a habitat map. Losses of EFH include removal of water from the water column and effects on prey of species that have designated EFH. Analysts should address alterations to critical habitat through the NEPA and ESA processes. 7. The three-dimensional extent of the discharge thermal plume should be mapped on the receiving water body. A narrative explanation should accompany the map and should discuss amounts of scouring and chemical contaminants and other constituents, in addition to heat, anticipated during various discharge scenarios. 8. Analysts should plot estimated salt drift isopleths from cooling towers on a base map showing aquatic habitats as applicable. 9. Other aquatic environmental impact analyses that may be needed to support NRC licensing decisions include the following: • entrapment, impingement, and entrainment • noise- and pressure-related