Trending toward renewable energy, energy providers confronted by coal ash disposal

A coal ash pond near a power plant – note its proximity to a river

 

In 2008, a coal ash pond dike at The Tennessee Valley Authority’s Kingston Power Plant collapsed, spilling 1.1 billion gallons of coal ash slurry into the adjacent Clinch River.  Worried observers took note.  Earlier this year, after Hurricane Florence recently barreled into South Carolina, utility Santee Cooper enlisted the help of private contractors to secure its coal ash ponds, which contain about 200,000 tons of wet ash and were in danger of spilling into the Waccamaw river.

Coal ash, just like wood ash from a fireplace, or charcoal ash from an outdoor grill, is light and powdery. In its dry form, wind can spread it far and wide, which is why utilities around the world mix it with water and store it in “ash storage ponds.”  These ponds are constructed specifically for coal ash storage and are located adjacent to coal-fueled power plants – and the rivers which provide cooling water to those plants.

A failure in the earthen berms that separate the Waccamaw River from the power plant’s ponds could have unleashed a plume of wet ash – which contains chemicals such as arsenic, lead and mercury – into the Waccamaw.  In February of 2014, North Carolina officials estimate up to 39,000 tons of coal ash spilled from Duke Energy’s Dan River Steam Station into the Dan River in Eden, N.C., about 80 miles upstream from the Kerr Reservoir. Ash or grey colored water was seen in the reservoir a few days after the coal ash spill, according to reports.

While natural gas, nuclear, solar and wind generated electricity are expected to satisfy America’s future electric power requirements, the demand for electricity is expected to grow by 30 percent over the next 25 years.  The nation’s largest and most efficient coal-fueled plants, which are outfitted with the latest environmental technologies, will most likely survive until they’re no longer efficient or newer environmental regulations require them to cease operations.  By 2034, the primary source of electricity, according to a projection from consulting firm Black & Veatch, will be natural gas. While natural gas is a fossil fuel, it releases 43 percent less CO2 than coal.  New reserves of natural gas, discovered in places like the Marcellus Shale Formation, which stretches from West Virginia to New York State, are expected to fuel the nation’s future power needs.

America may ultimately wean itself from coal, which also emits heat-trapping carbon dioxide and produces fine particulates that can affect the heart and lungs and cause serious illnesses. The country, though, cannot simply walk away from coal-fueled power plant sites, which include coal ash storage ponds, many of which are located next to major rivers and waterways that provide cooling water to power plants.

In 2017, the Tennessee Valley Authority, which generates power from hydro dams, nuclear power plants, and coal-fueled power plants, announced plans for the continued operation of Shawnee Fossil Plant, an important, nine-unit coal-fueled electricity generating facility.    It is expected that the plant’s existing landfill will reach capacity within the next 10 years. After considering various options as part of an Environmental Impact Statement, TVA is proposing to build and operate a new dry landfill on the site that will add another 20 years of storage capacity.

Dry landfills, typically located on higher ground, are lined with a barrier to contain materials and residual chemicals and protect groundwater sources. After they reach storage capacity, they can be covered with a liner and soil, and planted over to prevent erosion. And they can be monitored with instruments to ensure containment of the materials they hold.

Coal ash is the second largest stream of industrial waste in the US with about 130 million tons produced per year, according to southeastcoalash.org.

And according to the Environmental Protection Agency, coal ash is disposed in more than 310 active on-site landfills and 735 active on-site surface impoundments. The landfills average over 120 acres in size and 40 feet deep while impoundments average over 50 acres in size and 20 feet deep.

While capping existing coal ash storage ponds is an existing low-cost alternative preferred by utilities, many environmentalists and geologists believe dry storage in lined landfills on higher ground, capped with liners and soil, is a better long-term storage solution to the nation’s coal ash inventory.

CWI Alabama, LLC, an affiliate of Atlanta-based CWI Enterprises, operates a lined, 162-acre construction demolition and industrial waste landfill in Western Colbert County, Alabama.  The company’s founder, waste industry veteran Steve Witmer, purchased the site with plans to accept coal ash at the site – with the expectation that utilities will be required to relocate their ash storage to higher, dryer, ground.  The site is located between the TVA Colbert Plant and the Barton Industrial Park in western Colbert County.

“We were pleased to close on the site after having worked on acquiring an ideal location for two years,” Witmer explains.  “We are an environmental services company and work to remain good neighbors to communities and our customers.”

CWI Alabama modified the site to better utilize efficiencies in landfill design. The company expects the site to have a useful life that will exceed 50 years. CWI markets the landfill to municipalities, as well as commercial and industrial customers, including utilities.

Chris Hobson, a retired Southern Company employee who served as the utility’s senior vice president of environmental affairs, believes much of the nation’s coal ash may ultimately be removed from wet storage impoundments and moved to higher, dryer ground in lined storage facilities away from rivers and other waterways.

“Most power generation technologies, including coal-fueled plants, require a reliable source of water, thus they’re located adjacent to major rivers,” Hobson says. “And while drying and moving this material into lined and covered landfills will be a challenge, the industry may ultimately determine it is the best long-term storage solution.”