Water is vital to producing electricity. It is critical to the operation of most power generating facilities, particularly steam electric facilities. Besides cooling, water is used for bottom ash and fly ash transport, cleaning, low volume waste transport, and in the boilers themselves.
Water quality, availability, use and management are important issues to our industry, which is facing new rules related to the Clean Water Act. We are also taking measures to reduce our water consumption, improve our water quality and address water availability issues in the context of existing programs and with the expectation of new requirements in the future.
The rules that are pending include those for cooling water intake systems, known as 316(b) standards, and those that regulate wastewater discharge, known as Steam Electric Effluent Guidelines. The EPA is expected to finalize the 316(b) rule in 2013 and the Effluent Guidelines rule in 2014.
The new 316(b) standards are designed to protect fish and other aquatic organisms that come into contact with water intakes (more specifically, the screens that protect these systems from debris). Impingement occurs when aquatic organisms are drawn against an intake screen by the water current. Entrainment occurs when small fish, eggs or larvae are drawn into the cooling water system through the screen openings and are affected by heat, chemicals or physical stress.
We own and operate 31 power plants that could be affected by the proposed 316(b) rule. Solutions may likely include the retrofit of intake screen systems to reduce the impingement of fish and other aquatic organisms. EPA’s approach for entrainment makes it difficult at this time to predict if any additional modifications will be necessary.
The EPA recognized that its most expensive solution – cooling towers – would not be appropriate in many cases and said that it would consider alternatives based on each site. We support this approach.
Adopting cooling towers would be very problematic at our western coal plants, which operate in regions prone to prolonged droughts. In fact, these plants already use a closed-loop cooling system, where the reservoirs at the plants were built specifically to hold and recirculate the water used for cooling. Cooling towers also reduce plant efficiency.
Part of the Clean Water Act sets national treatment standards for wastewater discharges from steam electric generating facilities, and the EPA is expected to propose changes to them in April 2013. This rule would revise the existing, and add new, national standards for the treatment of power plant wastewaters. We are already starting to consider the possible impact this could have as we move from wet to dry handling of coal fly ash. In line with the current treatment standards, many of our coal ash ponds provide treatment of the ash wastewater from the plant, as well as many other waste streams. If the ash ponds are eliminated, the remaining waste streams from the plants would still need to be treated, but the technologies to do that could cost as much as $1 billion for the entire AEP fleet of coal-fired power plants.
Because it is so important to understand what will happen to various pollutants as they move through different processes and ponds at a power plant, we are expanding our use of a computer model to help us make these complex assessments. A great deal of information, such as the type of coal burned, the boiler type, the chemistry of the water, the size of the treatment ponds, the chemical properties of various pollutants, chemical reactions, weather conditions, etc., is entered into this model. It helps us to predict how changes to the plant will affect the different waste streams.
For example, the model will permit us to better estimate how adding a new scrubber or eliminating an ash pond will affect the wastewater produced by the plant. The model will also be used to help with water recycling decisions and to determine if water reuse will affect the final wastewater output or any intermediate water treatment steps through the different processes. The model was developed for the Mitchell Plant in West Virginia and will be tailored for site-specific conditions at other power plants. The model will also help us to ensure that changes to water management within the plant not only meet national effluent guidelines, but also do not create unexpected consequences or prevent us from meeting local water quality standards. The information generated by this effort will prove useful as we retrofit coal units in the coming years.
In August 2012, representatives from Ohio, Indiana and Kentucky signed the world’s largest interstate water quality trading plan. The agreement marks the first time states have joined together to approve such a program and AEP was one of the first utilities in the nation to participate. AEP began working with the Electric Power Research Institute (EPRI) and other partners in 2011 on a market-based approach to improve water quality in the Ohio River.
A drought in 2012 created low water challenges for the boats and barges of AEP’s River Operations that deliver coal to our power plants and other commodities to manufacturers on the inland waterways and for export through the Gulf. According to the National Oceanic and Atmospheric Administration (NOAA), July 2012 was the hottest month on record in the continental United States. Along with record heat, the drought covered 61 percent of the 48 contiguous states, according to NOAA’s Drought Monitor. The Midwest reached near-record drought conditions, where three-quarters of the nation’s soybean and corn crops are grown.
Low water levels have especially been an issue on the Mississippi River. About 500 million tons of cargo, such as coal, grain and fertilizer, move up and down the river each year. Low water levels due to the drought affected navigation in some locations on the lower part of the Mississippi River, causing some vessels to run aground. AEP’s River Operations business operates more than 3,000 barges, 60 towboats and 25 harbor boats on the nation’s inland waterways delivering cargo. But the low water levels in 2012 hampered that business and contributed to a decline in earnings compared with 2011.
The drought also affected operations on AEP’s hydroelectric facilities in 2012. Reservoir levels at Smith Mountain Pumped Storage Project in Virginia were approximately four feet below normal, requiring modifications to the water flows discharged from the plant. Following the dry summer, this winter’s wet weather created the opposite effect -- high water levels in early 2013 at the facility. The water levels rose so quickly and with such force that it washed clean the riverbanks of tributaries that feed Smith Mountain Lake. APCo has removed more than 1 million pounds of debris from the navigational channels on the lake, as required by the plant’s license. Learn more about Smith Mountain’s Debris Management Plan and about the plant’s shoreline management plan.