LimnoTech's efforts allowed AEP to consider cost-effective, energy-efficient, reliable responses to the new 316(b) Rule before it was released.

Fish Netting


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Success Story

316(b) Support for a Lake Michigan Nuclear Power Plant

In August 2014, USEPA published an update to Section 316(b) of the Clean Water Act. The 316(b) Rule aims to reduce injury and death of fish and other aquatic life caused by impingement and entrainment at power plants and industrial facilities with cooling water intake structures. American Electric Power (AEP), the owner and operator of the Donald C. Cook Nuclear Power Plant (CNP), requested support from LimnoTech to provide strategic guidance for compliance with the updated 316(b) Rule.

CNP is a 2,155 MW, two-unit nuclear power plant located on the southeastern shore of Lake Michigan near Bridgman, Michigan. The plant withdraws up to 1.5 million gpm of condenser and service water through three intake tunnels (with velocity caps) located 2,250 feet offshore in Lake Michigan. The complex nature of the source water, scale of the facility, and uncertainty related to several years’ delay in the release of the final regulation made the project especially challenging.


LimnoTech assembled a panel of experts to examine the 316(b) Rule revisions and to consider potential implications and opportunities for the CNP. In 2009 through 2014, LimnoTech conducted extensive field investigations, a screening-level analysis, and a preliminary design assessment of select alternatives to support strategic planning for compliance with the new 316(b) Rule. 

For some facilities, existing intake technologies (e.g., velocity caps) and/or previously collected data sets can potentially be used to comply with specific requirements of the 316(b) Rule. LimnoTech helped AEP identify and package information that could be directly used as a cost-effective first step of 316(b) Rule compliance. In 2015, LimnoTech is conducting a comprehensive entrainment characterization study to fulfill monitoring requirements of Rule Section (r)(9), provide data and information required to support compliance with other sections of the Rule, and support demonstration of the Best Technology Available (BTA) strategy selected for the CNP.


Early efforts to conduct initial field studies, screening level analyses, and expert panel engagement before the final 316(b) Rule release allowed AEP to proactively consider several potential alternatives for Rule compliance and to identify options. These analyses gave AEP a foundation to proactively and collaboratively engage with MDEQ and proceed with more detailed assessments, informed decision-making, and additional field studies once the final 316(b) Rule was released in 2014. The efforts provided AEP with the time and opportunity, in advance of the Rule finalization, to consider responses that could be more cost-effective, energy efficient, and reliable.