Electricity generation requires large amounts of water to produce steam, remove heat or power hydroelectric turbines. Some of the water naturally evaporates — what you see rising out of the large cooling towers at steam power plants is water vapor. Some of the water at power plants is cooled and reused. Most is returned back to its source.
Environmental concerns regarding water principally relate to the quantity of water withdrawn and consumed from rivers and lakes, the quality of the water returned to the source, and any effects on aquatic life. Southern Company system plants withdraw, on average, almost 4 billion gallons of water per day; about 93 percent of that water is returned to the river or lake. Performance »
The U.S. Environmental Protection Agency's final rule establishing standards for reducing effects on fish and other aquatic life caused by new and existing cooling water intake structures at existing power plants and manufacturing facilities became effective in October 2014. Implementation of the rule will be based on site-specific factors.
Southern Company supports reasonable regulations that take into account the great variation of impacts from plant to plant. The company continues to research technologies — including fish-return systems and "fish-friendly" or modified traveling screens — to minimize the impact of power plant intake structures on aquatic life.
The National Pollutant Discharge Elimination System controls water quality by regulating point source discharges into U.S. waterways. Southern Company system power plants have water discharge permits for pH, suspended solids, oil and grease, chlorine, temperature, iron, and other parameters. Typical permitted discharges include cooling water, ash ponds, coal pile runoff ponds, metal cleaning waste ponds, sump overflows, and oil/water separators. These points are monitored or sampled periodically in accordance with permit requirements.
Certain EPA regulations, called effluent guidelines, address materials discharged by thermoelectric power plants. EPA published revisions to the steam electric effluent guidelines in November 2015 regulating wastewater discharges primarily associated with coal combustion byproducts, such as coal ash and scrubber wastewaters. The revised limits and compliance dates will be incorporated into renewals of NPDES permits. Southern Company seeks to ensure compliance in the most cost-effective and efficient manner, while providing continued protection of water quality and aquatic resources.