By Dr. Richard W. Goodwin
Of the 131 million tons of power plant waste or Coal Combustion Byproducts [CCBs], 36% are disposed of in landfills and 21% are disposed of in surface impoundments. Recent upsets from surface impoundments and landfills have created a public media furor — focusing elected and appointed officials to demand more stringent regulatory control.
During the past several months, following the Tennessee Valley Authority [TVA] ash and scrubber sludge spill in Kingston, VA, the public and media have elevated this incident - engaging elected officials and federal/state regulators. This spill occurred on December 22, 2008, when an ash dike ruptured at an 84-acre (0.34 km2) coal waste containment area at the Tennessee Valley Authority's Kingston Fossil Plant in Roane County, Tennessee. 1.1 billion gallons (4.2 million m3) of coal fly ash slurry was released. It was the largest fly ash release in United States history.
In May 2009, the U.S. Environmental Protection Agency (EPA) signed an enforceable agreement with TVA to oversee the removal of coal fly ash slurry at the Kingston Fossil Fuel Plant. The cost of this clean-up is estimated at almost one billion dollars. During Jan. 2009 Public Works Hearings, Tom Kilgore [TVA CEO] said that TVA had chosen to implement inexpensive patches instead of more extensive repairs of the holding ponds, admitting, "Obviously, that doesn’t look good for us."
The New York Times advocates further regulation. “The lack of uniform regulation stems from the E.P.A.’s inaction on the issue, which it has been studying for 28 years.” USEPA Administrator Lisa Jackson promised, during her confirmation hearing, to promulgate stricter coal plant waste storage regulations. Capitalizing on the political opportunity of the TVA Kinston Spill will escalate with continued congressional hearings. Elected and appointed officials will find the coal industry an easy and demonized target to impose more stringent regulations.
These incidents and consequences should not indict coal-fired power plants or the electric utility industry; unexpected costs from ten to hundreds of million dollars and public embarrassment are sufficient punishments. How to avoid such upsets should be the focus of Coal Fired Power Plant operators and the Electric Utility Industry.
An Engineering Approach, reflecting demonstrated technology and recognizing CCPs chemical and geotechnical properties, should be embraced by the Electric Utilities with coal-fired power plants. Commitments to regulators to develop and implement this approach would curb excessive requirements. Electric utilities should capitalize upon the industry-wide knowledge and submit to USEPA as regulatory approaches are being developed.
If increased regulation translates into using CCBs in land disposal applications, with improved methods of placement [optimal compaction] and enhanced site management [capitalizing upon concrete-like behavior of coal combustion by-products], then such stronger regulation can be justified.
Consider the following uses of Power Plant Wastes to improve how they are land disposed:
PHYSICAL PROPERTIES OF FGD RESIDUE AND FLY ASH – Retrofitting Surface Impoundments as Grout to Strengthen Dike Walls
The particle size of FGD residue and fly ash shows this blend could be used as a grout material to stabilize existing CCB surface impoundment dike walls. When used as grout, the blend must be ability to penetrate between the interstitial soil spaces. Grouting existing soil dike wall would be about 90% less costly then slurry cutoff wall.
According to AECOM’s 6/25/09 Summary Report, a combination of the existence of an unusual bottom layer of ash and silt, the high water content of the wet ash, the increasing height of ash, and the construction of the sloping dikes over the wet ash were among the long-evolving conditions that caused a 50-year-old coal ash storage pond breach and subsequent ash spill at TVA’s Kingston Fossil Plant on December 22, 2008. Retrofit of surface impoundments, using FGD residue and fly ash and, where required, a cementious additive would prevent similar dike wall failures.
RESIDUE MANAGEMENT – Placement – Landfill Methodology
The inherent pozzolanic-like behavior of lime-laden CCBs enables achieving improved geo-technical properties i.e. strength, permeability. Achieving liner-like permeabilities, by capitalizing upon CCB’s inherent characteristics and applying Proper Placement Control, achieves cost savings of 65% over traditional disposal methods e.g. synthetic liners.
DEMONSTRATION PROGRAM – Landfill and Surface Impoundment Embankments
Considering the inherent engineering properties of CCBs justifies using this material to form surface impoundment dike walls. Approximately 27.5 million tons of CCBs are retained in surface impoundments. Preventing failure of these dike walls represents a primary issue for discussions between the electric utility industry and regulators. A demonstration program, based on laboratory and bench-scale testing, would indicate industry willingness to address future requirements in a cost-effective manner.
The electric utility industry with their trade and research organizations are urged to commit to conducting such programs (demonstrating the application of CCBs in land disposal) – showing a ‘good faith’ effort to cooperate with regulatory and addresses recent CCB disposal upsets.
S. Dewan; “Hundreds of Coal Ash Dumps Lack Regulation”; The New York Times; January 7, 2009
Goodwin, R.W.; Combustion Ash/Residue Management An Engineering Perspective; Noyes Publications/William Andrew Publishing; Mill Road, Park Ridge NJ 1993 (ISBN: 0 8155 1328 3) (Library of Congress Catalog Card No.: 92 47240)
RS Means; Building Design Construction Data; Kingston MA; 2006
Richard W. Goodwin, PhD, PE is an Environmental Consulting Engineer. Dr. Goodwin has more than 25 years of experience in the waste treatment, disposal, by-product utilization, conducting studies on conceptual engineering and system performance and operations, ash management, securing regulatory acceptance for construction and demolition recycling and disposal projects, investigating viability of Landfill Gas Energy Extraction from abandoned landfills, evaluation of landfill operations, and testimony for hazardous emissions for proposed landfills. He specializes in wastewater reuse and odor elimination. Expert on FGD BY-PRODUCT GYPSUM & FGD, SCR, ESP, CO2 capture technology pollution control coal-fired power plants. Dr. Goodwin has completed a conceptual study for Office of Secretary of Defense for Hazardous Waste Management in Iraq. He is working with electric utilities on permitting of new coal-fired power plants implementing Clean Coal Technology (consulted to USDOE in this area). Dr. Goodwin also consults to investment community including investment bankers, private equity and venture capital firms. Dr. Goodwin has recently been appointed Task Force Chairman Energy Conservation [Palm Beach County FL]. His current work includes anaerobic digestion and energy recovery of biomass; conversion coal-fired plants to bio-mass and Waste-to-Energy Resource Recovery facilities.