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
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CFR Title: 

Content:
ties, such as surface or ground water drawdown, noise, pressure changes, scour and erosion, storm-water runoff, dredged or excavated material disposal, water discharge plumes, and cooling tower drift. Studies of aquatic resources within the area of building and operation (plus a reasonable buffer based on the imprecision of design data) generally should be more detailed than for peripheral areas. The spatial extent and detail of baseline investigations may have to be expanded to account for cumulative impacts properly and to address the concerns of interested federal, state, tribal, local agencies, and private organizations. DG-4023, Page 7 The detail needed for baseline investigations may be less for proposed sites that have been partially developed (e.g., sites within an existing nuclear power plant property or a property with other energy production facilities) if the site has undergone past ecological investigation. However, generally, ecological data should be collected recently enough to allow an accurate assessment of existing conditions and potential impacts (i.e., after any anthropogenic or natural disasters that may have altered habitats). To describe the current condition of aquatic resources analysts may use descriptive field information gathered during previous environmental reviews, if updated and augmented, as necessary, with current field investigation data and supplemented with an analysis of new and significant information. The updated data collection needs to address habitats lost, degraded, and created by building existing facilities (e.g., loss of nearshore habitat during creation of an intake structure) and natural processes or anthropogenic activities that have taken place since collection of the earlier data. If the analyst uses historic data for comparisons or descriptive purposes, the analyst should justify why such a method is appropriate and scientifically acceptable. Because baseline investigations form the foundation for subsequent