Tomorrow, March 22nd, is World Water Day, and this year’s theme is Water and Energy. UN’s World Water Day website explains why:

Water and energy are closely interlinked and interdependent. Energy generation and transmission requires utilization of water resources, particularly for hydroelectric, nuclear, and thermal energy sources.

Conversely, about 8% of the global energy generation is used for pumping, treating and transporting water to various consumers. In 2014, the UN is bringing its attention to the water-energy nexus, particularly addressing inequities, especially for the ‘bottom billion’ who live in slums and impoverished rural areas and survive without access to safe drinking water, adequate sanitation, sufficient food and energy services.

It also aims to facilitate the development of policies and crosscutting frameworks that bridge ministries and sectors, leading the way to energy security and sustainable water use in a green economy. Particular attention will be paid to identifying best practices that can make a water- and energy-efficient ‘Green Industry’ a reality.

When I think of water and energy, nuclear power is usually the first thing that comes to mind, because nuclear reactors need massive amounts of water to provide cooling. Recently, though, the US has seen examples of how the use of coal for energy can end up damaging rivers. The chemical MCMH that contaminated West Virginia’s Elk River is used to wash coal, and as Jeff Biggers of Aljazeera America points out, West Virginia has also suffered from river and aquifer contamination from coal-slurry disposal and mountaintop-removal mining.

North Carolina residents also faced toxic contamination in one of their waterways after a Duke Energy containment pond spilled 39,000 tons of coal ash into the Dan River last month. (More recently, North Carolina regulators charged the company with pumping 61 million gallons of coal-ash wastewater into the Cape Fear River over a period of several months.)

Weeks before the Duke Energy spill, USA Today’s Duane W. Gang returned to Tennessee, where five years ago a devastating cascade of coal ash from the Tennessee Valley Authority’s Kinston Fossil Plant engulfed 300 acres of land and dumped 5.4 million cubic yards of coal ash into the Emory and Clinch rivers. The December 2008 disaster prompted some re-examination of the widespread practice of keeping coal-ash wastewater — a byproduct of coal burning that contains pollutants such as arsenic and mercury — in massive containment ponds. Gang writes:

Congress held hearings in the aftermath. The U.S. Environmental Protection Agency proposed news rules regulating coal ash, including classifying it as a hazardous material.

But five years later, coal ash remains largely unregulated. The EPA and Congress have not yet acted to strengthen oversight of the material. Industry groups and some lawmakers continue to oppose classifying coal ash as hazardous.

“The jury is still out on whether we will get the protections we need to prevent this from happening again,” said Stephen Smith, executive director of the Southern Alliance for Clean Energy in Knoxville, Tenn. “The final chapter hasn’t been written.”

To clean up the spill and restore the area, TVA has spent $1 billion and is on pace to spend $200 million more by the time the project finishes in 2015.

TVA also has spent $40 million studying the effects of leaving 500,000 cubic yards of ash in the river, where it has mixed with decades-old radioactive pollution from the Department of Energy’s nearby Oak Ridge nuclear reservation. For the next 30 years, TVA is required to monitor wildlife in the area.

… There are hundreds of coal-ash impoundments across the nation, and the EPA has found dozens that it believes are leaking. In the wake of the 2008 spill, some utilities, including TVA, vowed to convert to dry ash storage, a far safer way to handle the material.

In a recent settlement with environmental groups who sued it, EPA has committed to take final action on a long-delayed rule regulating coal ash by the end of 2014.

The US and multiple state regulatory systems have shown themselves to be inadequate to protect our waterways from contamination related to the use of coal-burning power plants.  On World Water Day, it’s worth considering how we can prevent our energy generation from endangering our water supply.