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Committed to efficient water use

Access to water is essential to Exelon’s production of electricity which supplies power to the equivalent of approximately 35 million homes in the United States.  We understand the importance of being responsible stewards of this critical resource, and we recognize the potential effects that climate change, increasing demand for water and more stringent regulations will have on our ability to access water resources in the future.

CDP Water Survey
In 2014, Exelon completed the Carbon Disclosure Project (CDP) Water Survey to provide transparency into our efforts to manage the use and risks associated with this important resource.   

Exelon CDP Water Response [PDF | 447 KB]

Water Utilization

With operations in a variety of geographic areas across the United States, we are focused on understanding the specific needs and sensitivities of the watersheds in which we operate and strive to incorporate their value into our business planning. In 2012, Exelon utilized about 43.6 billion gallons of water per day. Over 98% of the water used is for cooling in the electric generation process, returned to its source without any degredation in quality.

Exelon completed the 2013 Carbon Disclosure Project (CDP) Water Survey to provide transparency into our efforts to manage the use and risks associated with this important resource. 

Key Water Issues

The primary environmental issues associated with power plant cooling water systems are consumptive use of water, thermal discharge, and entrainment and impingement of aquatic organisms. In response to the growing effects of climate change, there are also impacts associated with changing water flows and temperature trends.  Exelon is monitoring watersheds to understand how these changes may impact the water resources with which we interact.  

Some of the sensitive watersheds that the company relies on are the Mississippi River; the Susquehanna River, which empties into the Chesapeake Bay; the Barnegat Bay in New Jersey; and the Delaware River. Although the broad issues mentioned above are common to all these watersheds, the specific characteristics and regional nature of water resource regulation necessitates the strategic managment of water use locally at each operating site. Some examples include:

  • Closed-cycle cooling water systems require adequate supplies of make-up water to replace that which is lost to evaporation.  At our Limerick nuclear plant, for example, we have developed an innovative approach for augmenting make-up water using water from abandoned coal mines.
  • In open-cycle cooling water systems, aquatic organisms can become entrained in the intake flow or become impinged on the intake screens. To address this condition, a variety of measures can be used, including reducing the flow velocity and using specially designed equipment that allows for the safe passage of organisms.
Conowingo and Muddy Run Relicensing
Exelon’s two hydroelectric power plants, Conowingo and Muddy Run currently hold licenses that expire in 2014.  For more information: 

Water Regulation

Exelon is actively engaged with the electric utility industry, which is advocating for specific regulatory outcomes that would achieve the most economical and effective reduction of environmental impacts. In March 2011, the EPA issued a proposed rule addressing existing power plant cooling water intakes, and EPA issued its final rule in May 2014.. Exelon continues to comply with the existing conditions of our National Pollutant Discharge Elimination System (NPDES) permits, while we are evaluating the requirements of the final rule.

Compliance Performance

Exelon has set a goal of zero water Notices of Violation (NOV) and Permit Noncompliances for company operations. NOVs are issued by a regulatory agency when a company is believed to have violated a permit condition or regulatory requirement.  Exelon self-reports violations of regulations and regulatory agency-specified environmental permit conditions when they are identified.

Exelon Corporation Sustainability Report | PDF 5MBMore information on Exelon's compliance performance can be found in the Exelon's Corporate Sustainability Report. PDFPDFs require software like the Adobe Acrobat Reader to be viewed properly.

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