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See also:

  1. Ecotoxicology Laboratory
    1. Whole Effluent Toxicity Testing
    2. Toxicity Identification Evaluation/Toxicity Reduction Evaluation
    3. Dredged Material Testing
    4. Sediment and Soil Toxicity Testing
    5. Water Effect Ratio Studies
    6. Additional Toxicity Testing
  1. Environmental Analysis
  1. Environmental Planning
  1. Environmental Permitting, Compliance, and NEPA
  1. Ecosystem Restoration
  1. Marine Sciences

For further information, please contact:


Dan Savercool, National Service Line Program Manager, at dsavercool@eaest.com.



One benefit of EA is that as a pioneer in Clean Water Act 316(b) compliance, we have a historic perspective as well as a present day understanding of the regulatory, scientific, and business issues surrounding the use of cooling water intake structures.






Location: Natural Resources > Section 316(b) Entrainment and Impingement Services

Section 316(b) Entrainment and Impingement Services

A National Leader in Clean Water Act Section 316(b) Studies

EA is a recognized leader in all facets of the Clean Water Act and U.S. Environmental Protection Agency (EPA) rules regarding 316(a) for thermal discharges and 316(b) for operation of cooling water intakes. In the early 1970s, EA pioneered the science of evaluating impacts of cooling water withdrawals from and discharges to surface waters. With the implementation of 316(b) Phase II regulations in 2004 governing existing power plants, we continued as a national leader in the design, conduct, and interpretation of entrainment and impingement studies. EA has conducted such studies at facilities throughout the country, on all waterbody types. Our scientists have helped more than 100 utility and industrial clients address 316(a) and 316(b), having produced many successful demonstrations for our clients.

Specialized Expertise in Entrainment and Impingement for
Section 316(b) Compliance

Working with industry groups and professional organizations, EA scientists have been active with issues involving the entrainment and impingement of fish and other organisms at cooling water intakes. During development of the Phase I and Phase II
316(b) rules, and the follow-up Notices of Data Availability, EA served as one of the principal consultants to the Utility Water Act Group and assisted in developing comments on the draft rule.

We are routinely requested to represent the regulated community and provide our expertise at national workshops and conferences addressing entrainment and impingement issues.


More recently, EA provided comments on the new draft rule that would replace the remanded Phase II rule. EA has conducted impingement and entrainment studies of fish and shellfish at over 75 power plants and industrial facilities to meet requirements up through the remanded Phase II rule. The new rule requires use of Best Technology Available to minimize impingement and entrainment losses at cooling water intakes. The determination that an existing intake with conventional fish protection devices is Best Technology Available can be supported by demonstrating that intake velocity and flow are low enough to minimize impingement and entrainment. Alternative technologies and operational modifications can also be evaluated to meet Best Technology Available requirements. We offer broad expertise in designing and implementing the field studies necessary to establish existing losses and conduct the necessary tests or measurements to support Best Technology Available determinations, including impingement survival studies and latent mortality studies of entrained organisms.

As a national expert in the environmental monitoring and assessment of the aquatic community, EA conducts the full suite of Clean Water Act 316(b) studies:

  • Alternative Technology Performance Studies
  • Demonstration Studies
  • Development and Population of 316(b) Databases
  • Entrainment
  • Source Water Biological Characterization Studies
  • Hydrographic Surveys and Modeling
  • Impingement
  • In-House Laboratories
  • Water Quality
  • Benefit Valuation
  • Peer Review of Entrainment Characterization Study Plans