Water Utilization
Exelon utilizes about 33.5 billion gallons of water per day, more than 99.99% of which is used for the generation of electricity by our low-carbon hydroelectric and nuclear plants. Nearly all of the water used each day — 99.3% of it —is returned to its source without the need for treatment. We understand the importance of being responsible stewards of this critical resource, and strive to incorporate its value into our business planning.
In 2010, we updated our water inventory to continue to trend our water use in support of developing plans to reduce consumptive water use where cost-effective and practical. We continued our support of restoration and maintenance of native fish species, and our commitment for the programs to reduce aquatic impacts. As we continue to refine the Exelon 2020 strategy we have broadened our considerations to include the vital role that water resources play in achieving our goal.
In 2011, 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.
- New to Exelon in 2012
Constellation uses approximately 6.5 billion cubic meters of water each year, returning most to its source water body. Find out more about their water programs in their CDP Water Response.
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 organism. 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.
Fish Protection
- For years, Exelon has funded research by the Electric Power Research Institute (EPRI) on technologies for fish protection associated with cooling water intake structures. The results have been used to inform the rulemaking process for the EPA's 316 (b) water intake regulations to ensure that the final regulations consider all aspects of the issue and technology options.
Stream Restoration
- Exelon Power partnered in 2010 with non-profit organization Trout Unlimited and the US Fish and Wildlife Service by providing funding to do stream restoration on Climbers Run in the Susquehanna River Watershed. These projects target sediment control along cold water streams.
Fish Passageways
- In 2010, Exelon Power completed construction and began operation of a fish passage facility at the Black Rock Dam on the Schuylkill River. This passageway, and a similar one Exelon constructes at the Norristown Dam in 2008, contribute to a larger effort to enable American shad and other migratory fish to travel upriver for the first time in nearly 200 years.
New Technology
- Constellation is working as part of Chesapeake Algal Consortium (ChAC) to install “in water” Aquatic Biomass Production System (ABPS) test units at C.P. Crane power station. This project may help to clean the water of the Chesapeake Bay by removing excessive nutrients and injecting needed oxygen, while producing biofuels that may be used in power generation.
Fish Lifts
- In 2010 Exelon’s Conowingo Dam fish lift assisted the migration of 37,757 American shad upstream in the Susquehanna River. The facility also provides space and resources in support of the Fish and Wildlife Service, as well as 30 miles of shoreline for fishing and recreation and 700 acres of community park land.
Fish Hatcheries
- Exelon's Quad Cities Fish Hatchery stocked the Mississippi River with 387,376 walleye and 7,407 hybrid striped bass in 2010. The hatchery’s annual production goal is 175,000 walleye and 10,000 striped bass.
Schuylkill River Restoration
- Exelon Nuclear supports the Schuylkill River Restoration Fund for improving water quality in the river and its tributaries. The Fund specifically focuses on projects that will mitigate abandoned mine drainage (AMD), stormwater run off and agricultural pollution.
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Water Regulation
Thermal discharges are regulated under the Clean Water Act Section 316(a), and entrainment and impingement is being addressed under Section 316(b). In March 2011, the EPA issued a proposed rule addressing existing power plant cooling water intakes, and EPA is expected to issue a final rule in July 2012. 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.
Exelon continues to comply with the existing conditions of our National Pollutant Discharge Elimination System (NPDES) permits, while it is evaluating its affected facilities (Oyster Creek, Peach Bottom, Dresden, Quad Cities, Clinton, Eddystone, Cromby, Fairless Hills, Handley, Mountain Creek, and Schuylkill) to develop plans for cost-effectively meeting the proposed changes to the rule.
On Dec. 8, 2010, Exelon Generation announced that it will permanently cease generation operations at Oyster Creek Generating Station by Dec. 31, 2019. This decision was made because the installation of cooling towers, as proposed by the New Jersey Department of Environmental Protection (NJDEP), would render the plant uneconomical. As a result of our decision to retire the plant early, the NJDEP determined that existing measures at Oyster Creek represent the best technology available for the facility’s cooling water intake to comply with Section 316(b) of the Clean Water Act through 2019.
Conowingo and Muddy Run Relicensing
- Exelon’s two hydroelectric power plants, Conowingo and Muddy Run currently hold licenses that expire in 2014. In March 2011, Exelon Generation presented results from the first year of studies to agencies and stakeholders as part of the FERC integrated relicensing process (ILP). The ILP creates the opportunity for agencies and stakeholders to provide feedback on these studies in order to determine if and what additional information would be required to pursue relicensing.
Compliance Performance
Exelon has set a goal of zero water Notices of Violation (NOV) and Permit Noncompliances for company operations. During the past three years, Exelon has reduced its number of water-related compliance issues. 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.
Water Notices of Violation
In 2010 the company received one Notice of Violation (NOV) from a regulatory agency.
- Exelon Nuclear experienced one NOV in 2010 at Braidwood related to exceeding the standard for allowable levels of Trihalomethanes (TTHM) in the Potable Water System. This NOV was attributed to material condition.
Water Permit Non-compliances
Exelon self-reports violations of regulations and regulatory agency-specified environmental permit conditions when they are identified. In 2009, Exelon had two self-identified water Permit Non-compliances related to water discharges.
- Exelon Nuclear had one permit non-compliance at Nuclear’s STC when the October Biological Oxygen Demand (BOD) limit at the Sewage Treatment Plant was exceeded.
- Exelon Power had one permit non-compliance event which occurred at Cromby station in June for exceeding its industrial wastewater treatment plant monthly average discharge limit for total suspended solids (TSS).
