Wednesday, April 20, 2011

EPA Proposes New Cooling Water Intake Structure Standards to Reduce Environmental Impact

The EPA published a proposed rule in the Federal Register today (April 20) that will affect (when finalized) many large cooling water dischargers to rivers in the Mississippi River Basin, including large electric utility plants.  The rule sets requirements that reflect the best technology available (BTA) for minimizing adverse environmental impact; requirements that would be implemented through National Pollutant Discharge Elimination System (NPDES) permits. 

Cooling water intakes can adversely impact aquatic organisms basically in two ways. The first is entrainment, which is the pulling in of organisms along with the cooling water.  The second way is through entrapment (also known as impingement): the blocking of larger organisms (such as fish) that enter the cooling water intake by a physical barrier such as screening equipment installed in the cooling water flow to protect downstream equipment (i.e., pumps, condensers, etc.) from damage or clogging.  Section 316(b) of the Clean Water Act requires that the location, design, construction and capacity of cooling water intake structures reflect the BTA for minimizing adverse environmental impacts.

Proposed Rule
The proposed rule is being issued pursuant to a settlement agreement with various environmental groups requiring that EPA promulgate a final rule no later than July 27, 2012. Portions of previous rules addressing cooling water intake structures for existing facilities were remanded to EPA for further consideration as the result of litigation.  Based on preliminary comments from environmental organizations involved in the rule-precipitating litigation (who have criticized the proposed rule for not establishing closed-cycle cooling as BTA), it is likely that any final rule would be challenged in litigation.

Under existing regulations, BTA for existing facilities is determined by the NPDES permitting authority using best professional judgment. Under the proposed rule, the permitting authority would retain substantial discretion to determine BTA for fish passing through the cooling water system, but the rule would establish numerical standards for fish trapped on the outer part of cooling water intake structures.  Facilities would be required to conduct fish mortality monitoring during the term of the permit.  The proposed rule also includes some changes to already-promulgated rules for new facilities.

The deadline for providing comments on the proposed rule is July 19, 2011.  Comments on the proposed rule can be provided to EPA by going to and following the on-line instructions for submitting comments; by e-mail to (Attention Docket ID No. EPA-HQ-OW-2008-0667); or by hand delivery to:
Water Docket
EPA Docket Center
EPA West Building Room 3334
1301 Constitution Ave., NW
Washington, DC 20004
(Attention Docket ID No. EPA-HQ-OW-2008-0667)

1 comment:

  1. Hi all,

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    Cooling Water Systems