Weekly Intake: A Water Intake Systems Blog

How Fish Screens Resolve Environmental Challenges

By Michael Stock

For years power plants and manufacturers have brought in water from nearby lakes and rivers for use in their facilities; but it isn't just water being brought in; fish, mollucks and other aquatic life and debris are as well. The aquatic life often does not survive the intake process, which is detrimental to the surrounding ecosystems. In an attempt to preserve the health of aquatic life and ecosystems, Section 316(b) was added to the nationally legislated Clean Water Act.


What is 316(b)?

Section 316(b) of the Clean Water Act puts in place regulations to combat this problem; regulations meant to "reduce impingement and entrainment of fish and other aquatic organisms at cooling water intake structures used by certain existing power generation and manufacturing facilities for the withdrawal of cooling water from waters of the United States."

Facilities that fall under the jurisdiction of 316(b) are existing facilities that have National Pollutant Discharge Elimination System (NPDES) permits and withdraw at least 2 million gallons per day from nearby water sources (25% of which is used only for cooling purposes). Industries affected by 316(b), include:

  • Power plants
  • Pulp and paper mills
  • Chemical manufacturing plants
  • Iron, steel and aluminium manufacturing
  • Petroleum refineries
  • Food processing/production
Visit the EPA's website to learn more about 316(b).


What does this mean for industry?

The facilities affected have seven options to choose from to meet the standards outlined in the Section 316(b). These options include:

  1. Operating a closed-cycle recirculating system
  2. Operating a CWIS that has a maximum through-screen design intake velocity of 0.5 foot per second (fps)
  3. Operating a CWIS that has a maximum through-screen actual intake velocity of 0.5 fps
  4. Operating an offshore velocity cap
  5. Operating a modified traveling screen that meets the EPA or state's Final Rule standard and is the BTA (best technology available)
  6. Implementing other combinations of technologies, management practices and operation measures that the EPA or state authorities determine is the BTA
  7. Achieve the specified impingement mortality rate for fish and mollusks of no more than 24%, as stated in the Final Rule.


Fish screens to the rescue!

Fish screens, like our Modified Ristroph Fish Handling Traveling Water Screen,  fall under option number 5 on the list above. Our fish screens are recognized by the EPA as the BTA to comply with the Section 316(b) regulation.

Fish screens are essentially a typical travelling water screen with a “fish friendly” Smooth-tex®  flat wire screen mesh to prevent descaling and a molded fish bucket that help minimizes turbulence, allowing the fish to be removed safely.

The video clip below shows a fish screen in action.

Installing fish screens in a facility doesn't mean that entirely new travelling water screens have to be purchased; components can be added to existing traveling water screens to make them fish friendly, extending the life of current equipment and reducing operating costs. Visit our website to learn more

Fish screens are not just for large scale operations that take in 2 million gallons of water a day. They can be used by facilities of any size that intake water.


Are you interested in installing fish screens in your facility?

Download our FREE Traveling Water Screens brochure to learn more!


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