316(b) Rule Controlling Cooling Water Intakes
316(b) Rule Controlling Cooling Water Intakes
316(b) Rule Controlling Cooling Water Intakes
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<strong>316</strong>(b) <strong>Rule</strong> <strong>Controlling</strong> <strong>Cooling</strong> <strong>Water</strong><br />
<strong>Intakes</strong><br />
Paul Geoghegan<br />
Principal Scientist<br />
Normandeau Associates<br />
Bedford, New Hampshire
Section <strong>316</strong>(b) of the CWA<br />
…the location, design, construction, and<br />
capacity of cooling water intake structures<br />
reflect the best technology available for<br />
minimizing adverse environmental impact...
<strong>316</strong>(b) <strong>Rule</strong><br />
• US power plants withdraw 201 BGD for<br />
cooling water<br />
• <strong>Rule</strong>making Effort under Section <strong>316</strong>(b) of the<br />
CWA ongoing since 1976<br />
• 2004 rule published but later withdrawn<br />
• New Draft rule in comment period
Typical <strong>Cooling</strong> <strong>Water</strong> Intake Screen
Impingement and Entrainment<br />
IMPINGEMENT<br />
ENTRAINMENT<br />
Adult and<br />
juvenile fish<br />
are impinged on<br />
the screen<br />
Fish in fish return trough<br />
Small juveniles, fish larvae<br />
and eggs pass through<br />
screens, through the CWS<br />
and return to ambient water.
POWER PLANT IMPACT<br />
ORIGINAL<br />
High<br />
IMPACT<br />
Thermal<br />
ACTUAL<br />
Low<br />
Impingement<br />
Low<br />
Entrainment<br />
High
Who does this rule apply to<br />
• Withdraw > 2 MGD and use 25% or more for<br />
cooling<br />
• Intake through-screen velocity ≤ 0.5 ft/sec<br />
– 15% blockage<br />
• Most power plants
Performance Standards<br />
• Impingement<br />
– Used Ristroph screen fish return system as BTA<br />
– Monthly mortality: 31%<br />
– Annual mortality: 12%<br />
• Entrainment<br />
– No BTA declared<br />
– Case by case determination<br />
– States to use BPJ based on 9 factors including<br />
social cost and benefit 125.98(e)
Design Flow of 50 MGD or more<br />
• Source water physical data 122.21(r)(2)<br />
• CWIS data 122.21(r)(3)<br />
• Source water biological characterization<br />
122.21(r)(4)<br />
• <strong>Cooling</strong> water system data 122.21(r)(5)<br />
• Impingement mortality reduction plan<br />
122.21(r)(6)<br />
• Performance studies 122.21(r)(7)<br />
• Operational status 122.21(r)(8)
Actual Flow of 125 MGD or more<br />
• All of the above plus:<br />
• Entrainment characterization study 122.21(r)(9)<br />
• Feasibility and cost evaluation study 122.21(r)(10)<br />
• Benefits valuation study 122.21(r)(11)<br />
• Non water-quality and other environmental<br />
impact study 122.21(r)(12)
Weaknesses<br />
• Doesn’t account for site specific costs for<br />
impingement<br />
– Offshore intakes<br />
• Doesn’t account for steps already taken<br />
– Ignores results of mandated monitoring programs<br />
• Impingement mortality of shellfish<br />
– Comparable to that achieved by barrier net<br />
– What’s a shellfish<br />
– Even for a few shellfish
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