From: John Rogers <JRogers@ucsusa.org>

To: Maryt Smith/DC/USEPA/US@EPA, Julie Hewitt/DC/USEPA/US@EPA, Paul Shriner/DC/USEPA/US@EPA, OW-Docket@EPA
Date: 12/21/2011 04:46 PM Subject: Docket ID No. EPA-HQ-OW-2008-0667 - new UCS-led analysis on power plant water

use

Director Mary Smith, Dr. Julie Hewitt, and Mr. Paul Shriner U.S. Environmental Protection Agency Washington, D.C.

RE: Docket ID No. EPA–HQ–OW–2008–0667, National Pollutant Discharge Elimination System – Cooling Water Intake Structures at Existing Facilities and Phase I Facilities -- 76 Fed. Reg. 22,174 (April 20, 2011)

Dear Director Smith, Dr. Hewitt, and Mr. Shriner,

A report released last month presents analysis that is relevant to the EPA rule-making around CWA 316(b). The report, Freshwater Use by U.S. Power Plants: Electricity’s Thirst for a Precious Resource, is the first major product of the Energy and Water in a Warming World initiative (EW3), a Union of Concerned Scientists-organized collaboration among leading energy, water and climate experts. It provides the first systematic assessment of both power plants’ impacts on freshwater resources across the United States and the quality of information available to help public- and private-sector decision makers make water-smart energy choices.

The analysis presented in the report covered several topics pertinent to the EPA rule-making. The analysis included examination of power plant water use data reported by power plant operators and compiled by the EIA, which GAO (2009) pointed out were “the only federally collected, national data available on water use and cooling technologies at individual power plants”. Our analysis examined the 2008 data and compared them to calculations of potential power plant water use based on data from a meta-analysis of water use studies (Macknick et al 2011).

In doing that comparison, our analysts found significant gaps and apparent inaccuracies, with important implications for assessing power plant water withdrawals and consumption and understanding the implications of that water use.

The analysis also included an assessment of water-supply stress, using a peer-reviewed index developed by the U.S. Forest Service. That analysis, based on the sample inputs, showed indicationsof water-supply stress in both expected areas (much of the Southwestern United States) and lessexpected areas (water basins in the Midwest and Southeastern U.S.) (Fig. 10 in the attached full report).The analysis also showed where water use for power plant cooling was the primary driver of watersupply stress, including many basins in the eastern U.S. (Fig.11). The analysis found that 400 out of 2,106 watersheds (eight-digit Hydrologic Unit Codes, or HUC-8) across the country were experiencing water-supply stress, and that power plants, by tapping water resources for cooling purposes, contributed to water-supply stress in one-fifth of those.

The report also examines reliability issues based on power plants’ water dependencies, issues which have implications for the availability of power plants, particularly during periods of drought and heat waves, and for the costs for make-up power that are borne by ratepayers in such instances.

Attached for your consideration please find PDFs of the report and supporting materials (glossary, detailed methodology, and additional data/analyses/graphics). The report and the supporting materials are also available at www.ucsusa.org/electricity-water-use. More information on the Energy and Water in a Warming World initiative is available at www.ucsusa.org/ew3.Thank you, in advance, for your consideration of this information and this important issue. Please feel

free to contact me with any questions about this analysis or the EW3 initiative.

Sincerely,

John Rogers

John Rogers Senior Energy Analyst Co-Manager, Energy and Water and in a Warming World initiative Union of Concerned Scientists Two Brattle Square, Cambridge, MA 02238

Tel: 617-301-8055 jrogers@ucsusa.org Founded in 1969, the Union of Concerned Scientists is an independent, science-based nonprofit working for a healthy environment and a safer world. www.ucsusa.org | Join our citizen action network or expert network | Support our work | Join the conversation on our blog or follow us on Facebook and Twitter.(See attached file: ew3-freshwater-use-by-us-power-plants_apx-b_graphical.pdf)(See attached file: ew3-freshwater-use-by-us-power-plants_glossary.pdf)(See attached file: ew3-freshwater-use-by-us-power-plants.pdf)(See attached file: ew3-freshwater-use-by-us-power-plants_apx-a_methodology.pdf)