EPA 316(b) is still on the horizon, and with convergence of the planned rule announcement and Power Gen, it's a fun game for a small set of equipment manufacturers and consultants to come up with a guess as to what happens next.
First, I'll provide a general update, then some a quick update on what Cook Legacy has been doing on this issue.
The way way back.
The rule requires that power plantsused best available technology to minimize Adverse Envrionmental Impact at cooling water intake structures. It was put forward by EPA, and was challenged in 1977. At that point EPA provided guidance to the regulators but no real standard. As a result of further challenges from environmental groups new rules were issued in 2001. This was planned to be put forward in three phases; Phase 1 for new plants, Phase 2 for intakes over 50 MGD, and Phase 3 focused on Oil & Gas. After challenges from environmental groups and various attorneys general the rule for the power generation and oil & gas were remanded. The new rule (set to be out early this month after a few delays) governed development of facilities >4 MGD.
What's Next
The rule was set to be out on the 4th of November. Given the government shutdown the rule was initially delayed day-for-day and is now due on the 14th of January. The rule provides two paths for compliance:
Impingement (Lower Flow, Catch & Separate, or Velocity Reduction)
Facilities can meet impingement standards with three basic approaches:
1. Meet numeric standards, 88% mean survival improvement from a measurement baseline.
2. Lower the velocity through the screen (which will probably mean the first point of contact with the fish) to 0.5 f/s
3. Install ristroph buckets, or some form of modern fish handling capability.
Entrainment
Entraintment will be handled on a case-by-case basis, requireing lots of study. The basic approaches are either some form of fine mesh screening or lowered flow.
The NODA
One can look to the NODA for some guidance on what the color of the final rule. The specific implementation remains to be seen but generally speaking there will probably be three big changes:
1. Create mechanisms to take credit for improvements already made to equipment or process.
2. Clean up the timing issues that arise from the differing impingement & entrainment standards, such that people have the benefit of a more complete body of research before making decisions, and can install a workable solution for both standards.
3. Build in some regulatory flexibility for "weird" sites, with either species of concern or a very low basline.
What We Are Doing
Cook Legacy's primary role is in the design and manufacture of cylindrical wedge wire screens. The general rule for wedgewires is "They're great...if they fit."
So our primary focus has been on solving the technical challenges so that wedgewires can fit in more places.
Advanced Flow Modification
The heart of wedgewire screening technology is the flow modifier. A properly designed screen has a flow modifier so that flow across the screen is consistent and low. This prevents clogging and allows fish to sense and avoid the flow field. Previous solutions were effective, but had a very narrow aspect ratio (the screen could not be much longer than it's diameter). The new flow modifier allows the use of screens in shallow water.
Modified Screen Geometries
One benefit of the advanced flow modifier is that it supports the use of innovative screen geometries such as the Hemi Screen and the Quad Screen, which fit in locations that traditional tee screens will not.
Debris Jet and IceBreak
Several sites would be suitable for the use of cylindrical wedge wire screens, except for occasional debris loading events. For these situations Cook Legacy developed the DebrisJet, which uses a sparge of compressed air to sweep away debris from the bottom of the screen. Similarly, the IceBreak system halts the formation of sheet and frazil ice on the screen
Flow Blade
One of the most important variables that predict a screen's environmental performance is the ratio of the velocity sweeping past the screen to the through slot velocity. For some sites, such as estuarine intakes, this ratio will vary. Cook Legacy developed the flow blade in order to create consistent velocity past the screen.
HZI+
In evaluation of sites, facilities must test the Hydrodynamic Zone of Influence, the area around the intake which is impacted by the intake flow. Cook Legacy has developed a design library to evaluate typical intake structures for HZI.
For more information on these technologies, contact us at sales.waterscreen.com
First, I'll provide a general update, then some a quick update on what Cook Legacy has been doing on this issue.
The way way back.
The rule requires that power plantsused best available technology to minimize Adverse Envrionmental Impact at cooling water intake structures. It was put forward by EPA, and was challenged in 1977. At that point EPA provided guidance to the regulators but no real standard. As a result of further challenges from environmental groups new rules were issued in 2001. This was planned to be put forward in three phases; Phase 1 for new plants, Phase 2 for intakes over 50 MGD, and Phase 3 focused on Oil & Gas. After challenges from environmental groups and various attorneys general the rule for the power generation and oil & gas were remanded. The new rule (set to be out early this month after a few delays) governed development of facilities >4 MGD.
What's Next
The rule was set to be out on the 4th of November. Given the government shutdown the rule was initially delayed day-for-day and is now due on the 14th of January. The rule provides two paths for compliance:
Impingement (Lower Flow, Catch & Separate, or Velocity Reduction)
Facilities can meet impingement standards with three basic approaches:
1. Meet numeric standards, 88% mean survival improvement from a measurement baseline.
2. Lower the velocity through the screen (which will probably mean the first point of contact with the fish) to 0.5 f/s
3. Install ristroph buckets, or some form of modern fish handling capability.
Entrainment
Entraintment will be handled on a case-by-case basis, requireing lots of study. The basic approaches are either some form of fine mesh screening or lowered flow.
The NODA
One can look to the NODA for some guidance on what the color of the final rule. The specific implementation remains to be seen but generally speaking there will probably be three big changes:
1. Create mechanisms to take credit for improvements already made to equipment or process.
2. Clean up the timing issues that arise from the differing impingement & entrainment standards, such that people have the benefit of a more complete body of research before making decisions, and can install a workable solution for both standards.
3. Build in some regulatory flexibility for "weird" sites, with either species of concern or a very low basline.
What We Are Doing
Cook Legacy's primary role is in the design and manufacture of cylindrical wedge wire screens. The general rule for wedgewires is "They're great...if they fit."
So our primary focus has been on solving the technical challenges so that wedgewires can fit in more places.
Advanced Flow Modification
The heart of wedgewire screening technology is the flow modifier. A properly designed screen has a flow modifier so that flow across the screen is consistent and low. This prevents clogging and allows fish to sense and avoid the flow field. Previous solutions were effective, but had a very narrow aspect ratio (the screen could not be much longer than it's diameter). The new flow modifier allows the use of screens in shallow water.
Modified Screen Geometries
One benefit of the advanced flow modifier is that it supports the use of innovative screen geometries such as the Hemi Screen and the Quad Screen, which fit in locations that traditional tee screens will not.
Debris Jet and IceBreak
Several sites would be suitable for the use of cylindrical wedge wire screens, except for occasional debris loading events. For these situations Cook Legacy developed the DebrisJet, which uses a sparge of compressed air to sweep away debris from the bottom of the screen. Similarly, the IceBreak system halts the formation of sheet and frazil ice on the screen
Flow Blade
One of the most important variables that predict a screen's environmental performance is the ratio of the velocity sweeping past the screen to the through slot velocity. For some sites, such as estuarine intakes, this ratio will vary. Cook Legacy developed the flow blade in order to create consistent velocity past the screen.
HZI+
In evaluation of sites, facilities must test the Hydrodynamic Zone of Influence, the area around the intake which is impacted by the intake flow. Cook Legacy has developed a design library to evaluate typical intake structures for HZI.
For more information on these technologies, contact us at sales.waterscreen.com