Lessons Learned From A Full-Scale Discrete In-Situ Stabilization Project For Ccr Impoundment Closure,
2026
ENTACT, LLC
Lessons Learned From A Full-Scale Discrete In-Situ Stabilization Project For Ccr Impoundment Closure, Tony Moran, Paul Jennings, Jacob Susser, Tim Silar
World of Coal Ash Proceedings
ENTACT, in collaboration with Silar Services, Inc., the patent holder of Discrete In-Situ Solidification (DISS) technology, has successfully performed a full-scale implementation of DISS in a Coal Combustion Residual (CCR) impoundment. DISS hydraulically isolates ash from surrounding groundwater by constructing a low-permeability barrier at the impoundment bottom to treat a layer of ash and tying into underlying natural soil layers. DISS enables targeted stabilization within a designated treatment zone, minimizing the disturbance of overburden compared to traditional excavation methods and reducing the use of costly cementitious reagents. The process starts with Reagentless Drilling of the overburden CCR utilizing a specialized …
From Clogs To Compliance: Overcoming Persistent Leachate Head Issues In Ccr Landfills,
2026
TRC
From Clogs To Compliance: Overcoming Persistent Leachate Head Issues In Ccr Landfills, Breanne Kahnk, Zachary Bauman
World of Coal Ash Proceedings
State and federal regulations require that landfills, including coal combustion residual (CCR) landfills, be designed and operated to maintain leachate head levels of less than 30 centimeters (approximately 1 foot). While proper leachate collection system design and routine maintenance are critical for meeting this requirement, challenges such as clogging of drainage media, pipes, fittings and/or pipeline perforations, settlement of collection pipes, and breaks in the piping system can lead to elevated leachate levels, posing risks to compliance and long-term system performance. TRC will provide an overview of leachate collection system regulatory requirements along with design, operation, and maintenance strategies that …
Plasma Coal Ash Processing For Enhanced Recovery Of Rare Earth Elements & Precious Metals: Proven From R&D To Commercial Plants,
2026
Plasma System LLC USA
Plasma Coal Ash Processing For Enhanced Recovery Of Rare Earth Elements & Precious Metals: Proven From R&D To Commercial Plants, George Paskalov, Victoria Campbell, Jason Honigberg
World of Coal Ash Proceedings
Our Radio-frequency Plasma System is an ash pretreatment before the application of extractive metallurgy and addresses current elemental, methodological, and technological limitations of complex and refractory coal ash. Our system data shows from 10-20% improved recovery, to 9x-100x. RFP can access all metals contained in coal ash. Our focus is not on the alteration of established methodologies, such as cyanidation for non-refractory ore, which has a proven return and capacity to achieve target revenue at-scale. Using the RFP systems, no waste is created, overburden can be more easily dealt with, and no metal content will be left behind. We assert …
Probing The Critical Element Chemistry Of Coal-Combustion Fly Ash: Electron Microbeam Investigations Of The Spent Ash From The Pilot-Scale Acid Extraction Of Rare Earth Elements From A Beneficiated Kentucky Fly Ash, James Hower
World of Coal Ash Proceedings
Fly ash derived from the combustion of an eastern Kentucky high volatile bituminous coal blend was beneficiated to yield a <75-μm product with a reduction in the carbon and spinels and reacted with a strong acid in a pilot-scale unit to extract rare earth elements. Electron microscopy showed a wide range of rare earth-bearing minerals. The acid-extracted fly ash had a rim that was depleted in REE and in most other elements except silicon.
Standardization Of Coal Ash Testing, Classification, And Harvesting,
2026
EPRI
Standardization Of Coal Ash Testing, Classification, And Harvesting, Benjamin Gallagher, Chris Frishcosy, Eric Hageman
World of Coal Ash Proceedings
Standards such as product specifications, test methods, practices and guides play a crucial role in supporting both commerce and science. Standardization helps build consistency and reliability whether it pertains to the performance of an ingredient in a product or in the measurement of a material characteristic. Coal combustion products, such as coal ash and synthetic gypsum, exhibit unique characteristics and many standard have been developed to characterize these materials and support their beneficial use. ASTM is a voluntary, consensus-based organization, and publishes many standards related to coal combustion products. Currently, there are seven ASTM standards related to chemical analysis of …
Leachate Quantification And Reduction – One Facility’S Path To Zld,
2026
EOT, LLC
Leachate Quantification And Reduction – One Facility’S Path To Zld, Cedric Ruhl
World of Coal Ash Proceedings
The Environmental Protection Agency (EPA) promulgated Effluent Limitation Guidelines (ELG) that govern liquids discharged from energy production facilities. According to the ELG, energy production facilities that burn coal beyond December 31, 2034 must convert to a Zero Liquid Discharge (ZLD) system by December 31, 2029*. This presentation focuses on one coal-burning facility’s strategy to meet ZLD requirements. The predominant source of liquid that will be treated by the proposed ZLD system is leachate from an active coal combustion residual (CCR) landfill. Is the ZLD’s design capacity suitable for average leachate flow conditions? Is there enough leachate storage volume to manage …
Impacts Of Updating Background Groundwater Statistics For Ccr Compliance,
2026
HDR
Impacts Of Updating Background Groundwater Statistics For Ccr Compliance, May Raad, Molly Reeves
World of Coal Ash Proceedings
In 2017, many power utilities adopted statistical methods to comply with the EPA’s Coal Combustion Residuals (CCR) Rule under the Hazardous and Solid Waste Management System. By 2017–2018, most owners completed initial statistical evaluations for detection and assessment monitoring to meet CCR deadlines. Groundwater sampling and analysis requirements in Parts 257.95, 257.98, and 257.102 are critical for compliance, yet implementation is complex. Subsections 257.93(f) and (g) lack clarity on which statistical tests to apply or how to address distributions and outliers. Additionally, the Rule does not specify when or how to update background threshold values (BTVs), though EPA’s Unified Guidance …
Comparison Of Residuals From Neighboring Power Stations With Different Coal Combustion Technologies,
2026
U.S. Geological Survey
Comparison Of Residuals From Neighboring Power Stations With Different Coal Combustion Technologies, Allan Kolker, Denise Levitan, Brett Valentine
World of Coal Ash Proceedings
Due to the ongoing need for critical minerals, coal combustion residuals (CCR), like fly ash, have been evaluated as a potential source of critical minerals, particularly rare earth elements (REEs). Previous studies have found that REEs in fly ash are largely contained within aluminosilicate glass from which they are difficult to extract. However, these studies have predominantly studied CCR from conventional pulverized coal fired (PCF) plants. PCF plants use higher temperatures (≥1300°C) than do circulating fluidized-bed (CFB) plants (~900-950°C). Samples of feed coal, fly ash, and bottom ash were collected from two adjacent Vietnamese coal-fired power stations, one with a …
Ai-Guided Upcycling Of Coal Combustion Residues In Blended Cement And Concrete,
2026
Missouri University of Science and Technology
Ai-Guided Upcycling Of Coal Combustion Residues In Blended Cement And Concrete, Hongyan Ma
World of Coal Ash Proceedings
Coal combustion residues (CCRs), including fly ash, bottom ash, desulfurization gypsum, etc., on specification or off-specification, remain an abundant yet underutilized byproduct of power generation. While these materials have long been considered as supplementary cementitious materials (SCMs), their variable chemical and physical characteristics limit broader adoption in blended cement and concrete. This study introduces an AI-guided framework to accelerate the upcycling of CCRs into high-performance construction materials. By integrating materials informatics, machine learning models, and experimental validation, the framework enables rapid property prediction and performance-based preprocessing recommendation or mix design optimization for diverse CCR sources. Preliminary results demonstrate the ability …
Advancing Ccr Site Management With Rapidly Deployable Gccm Technology For Runoff And Drainage Control,
2026
Concrete Canvas, USA
Advancing Ccr Site Management With Rapidly Deployable Gccm Technology For Runoff And Drainage Control, Nathan Ivy
World of Coal Ash Proceedings
GCCM’s were first invented over 20 years ago. These products combine both a concrete – hard armor – top surface for protection and durability and a geomembrane bottom surface for lower permeability. Originally used for erosion control, smaller drainage channel and remediation projects, this presentation discusses the newest iteration in GCCM technology. This product incorporates a 12 mil LLDPE backing which allows for thermal bonding and significant reduction in seepage at the joints. It can be used in a wide variety of applications from drainage ditches and swales to water and wastewater conveyance along with slope protection and erosion control …
Ccr 2026: The Plot Thickens—Your Complete Guide To What’S Next,
2026
Burns & McDonnell
Ccr 2026: The Plot Thickens—Your Complete Guide To What’S Next, Mark Rokoff
World of Coal Ash Proceedings
The landscape of CCR management is poised for significant transformation with the proposed EPA regulation introduced in early 2026. This presentation will provide a clear and enhanced summary of the key points in the proposed rule, highlighting the significant changes and implications for the industry. Where appropriate, it will be further enhanced by benchmarking data to compliment the key points and the effect to the “CCR Universe”. The proposed regulation aims to adjust the requirements for effective CCR management, introducing new compliance measures and timelines that will impact owner/operators across the board. Key discussion points will include: • Summary of …
Thermal And Mechanical Activation Of Estonian Oil Shale Cfbc And Hydrated Legacy Fly Ash As An Alternative Binder System For Opc Replacement,
2026
Tartu University
Thermal And Mechanical Activation Of Estonian Oil Shale Cfbc And Hydrated Legacy Fly Ash As An Alternative Binder System For Opc Replacement, Peeter Paaver
World of Coal Ash Proceedings
This study investigates high volume of Ordinary Portland Cement (OPC) substitution with fly ash based calcium sulfoaluminate binder. The utilization of circulating fluidized bed combustion (CFBC) boilers imposes limitations on the recycling of fly ash due to its lower combustion temperature inhibiting the formation of reactive calcium silicate minerals resulting in diminished pozzolanic properties of the ash paste. Our previous research (Paaver et al., 2020, 2022) has demonstrated that the mechanical activation of sulfur and calcium-rich Estonian oil shale CFBC fly ash produces calcium sulfoaluminate (CSA) type active binder allowing high-volume OPC replacement of up to 50%, with a reduction …
Benefits Of Containerized Water Treatment Systems For Coal-Fired Power Plants,
2026
GWTT - Ground/Water Treatment Technology
Benefits Of Containerized Water Treatment Systems For Coal-Fired Power Plants, Andrew Vincent
World of Coal Ash Proceedings
Containerized systems deliver many of the same functional benefits as housing treatment equipment in permanent buildings, while significantly reducing engineering, construction, and installation costs. By containerizing a water treatment system, a substantial portion of fabrication, assembly, and testing can be completed in a controlled shop environment rather than in the field. This approach greatly reduces on-site labor requirements, mobilization duration, and overall installation complexity. Once delivered to site, containerized systems can be used as permanent installations. Alternatively, they offer the flexibility to be relocated within a plant or transferred between different sites as operational needs change. Multiple containerized systems can …
Rare Earth Element Distribution And Mineral Host In Coal Derived Ash From South African Power Stations,
2026
University of Johannesburg,
Rare Earth Element Distribution And Mineral Host In Coal Derived Ash From South African Power Stations, Sanki Biswas, Nicola Wagner, Oftense Moroeng
World of Coal Ash Proceedings
The global shift toward low-carbon energy systems, electric mobility, and digital technologies has sharply increased the demand for critical minerals, including rare earth elements (REY) vital for permanent magnets, batteries, wind turbines, photovoltaic cells, semiconductors, and modern defence applications. Coal by-products—particularly coal fly ash (CFA) and coal bottom ash (CBA)—are emerging as promising secondary sources of REY, but their economic viability depends on effective enrichment and extraction methods. South Africa’s coal-fired power plants generate nearly thirty million tonnes of coal-ash each year. This study investigates REY concentrations in CFA and CBA collected from five major power stations (PS-1 to PS-5) …
Lessons Learned From Managing Ash Pond Closure Waters,
2026
Tennessee Vallely Authority
Lessons Learned From Managing Ash Pond Closure Waters, Danny Stephens, Tom Geeza, Phil Benson, Ashwin Ranna
World of Coal Ash Proceedings
The water management issues created by ash pond closure are complex and can create technology selection and operational management challenges. Ash dewatering activities produce highly variable effluents, depending on ash composition, aging, and dewatering and stormwater management techniques. Effluent limitations can also be highly variable, depending upon the size of the receiving body and the anticipated composition of the effluent stream. The user often faces competing risks: installing an unnecessarily complex and expensive treatment plant, being limited on closure activities by limitations in water treatment capabilities, or both. This paper presents several lessons learned from assessing ash closure water management …
Epri Ccp Beneficiation Research Update,
2026
EPRI
Epri Ccp Beneficiation Research Update, Benjamin Gallagher, Patrick Webb
World of Coal Ash Proceedings
Coal combustion products (CCPs) are frequently utilized as supplementary materials in cement and concrete manufacturing. With an estimated 2 billion metric tons stored in repositories across the United States, interest in beneficial use has expanded beyond class F fly ash to include ponded and high-LOI ash. Beneficiation provides a critical pathway for managing CCP repositories, particularly under closure-by-removal strategies, and where ash sources have historically been difficult to process. Research conducted at EPRI’s Ash Beneficial Use Center (ABUC) examines the feasibility of processing these ash types into usable products and offers insights into repository variability and classification. Furthermore, the study …
Risk Evaluation Of Small Coal Combustion Residual Management Unit (Ccrmu) Fills,
2026
Gradient
Risk Evaluation Of Small Coal Combustion Residual Management Unit (Ccrmu) Fills, Andrew Bittner, John Kondziolka, Qian Zhang, Masoud Arshadi
World of Coal Ash Proceedings
US EPA expanded the scope of CCR regulations in 2024 to areas of historical CCR placement not regulated under the 2015 CCR rule, including CCR used as fill. US EPA presented new risk analyses specific to CCRMU fills and defined different regulations for CCRMU fills from 1 to 1,000 tons, noting uncertainty as to whether there was a size of CCRMU fill below which acceptable risks could be expected. This research fills US EPA's stated data gap by modeling and analyzing impacts from small CCRMU fills. Modeling was conducted using the same methods, models, and most of the same inputs …
Consolidation Modeling To Support Closure Planning Of An Upstream Raise Ccr Surface Impoundment Containing Fgd Material, Tanya Walkenbach, Craig Schuettpelz, Todd Stong, Shane Stockdill
World of Coal Ash Proceedings
Rainbow Energy Center’s (REC’s) Coal Creek Station has managed calcium sulfite flue gas desulfurization (FGD) material in composite-lined upstream raise surface impoundments since 2001. The upstream raise surface impoundment utilizes bottom ash (drainage zone) and fly ash (structural zone) produced at Coal Creek Station to contain the FGD placement. FGD material was hydraulically sluiced to the center of the 110-acre Upstream Raise 92 (UR92) coal combustion residual (CCR) unit between 2001 and 2021. The FGD was deposited to a maximum thickness of approximately 100 feet in the center of the unit. Significant consolidation of FGD material occurred with subsequent FGD …
Investigating The Performance Of Processed Stockpile Fly Ash For Low Carbon Concrete,
2026
School of Science and Engineering, University of Dundee
Investigating The Performance Of Processed Stockpile Fly Ash For Low Carbon Concrete, Michael Mccarthy, Arfas Habeeb, Laszlo Csetenyi, Roderick Jones
World of Coal Ash Proceedings
Reducing embodied carbon in concrete has increasingly focused on clinker substitution through the use of supplementary cementitious materials (SCMs). However, the local availability of fly ash, a widely used SCM in the UK, offering benefits in this role, has reduced over the past decade, as coal-fired electricity generating plants have gradually been taken out of service. Attention has, therefore, increasingly focused on fly ash from stockpile and landfill sites to maintain supply, i.e., material not used following production and put into storage. Most UK fly ash originated from the burning of bituminous coal, producing low-lime siliceous material, which although undergoing …
Solar Solution For Closed Ccr Units And Adjacent Land,
2026
Watershed Geo
Solar Solution For Closed Ccr Units And Adjacent Land, Chris Fairey
World of Coal Ash Proceedings
Solar Solution for Closed CCR Units and Adjacent Land Chris Fairey1, Kenny Hughes1 1Watershed Geo, 1125 Sanctuary Pkwy, Suite 180, Alpharetta, GA 30009 KEYWORDS: Solar, Racking, Brownfield, Greenfield, Slopes, PowerCap® ABSTRACT With the reduction in coal fired power generation, there is a consistent trend in the industry to supplement generation with solar power. The property located within and surrounding these decommissioned power plants offers a significant opportunity to create a renewable solar power asset. The PowerCap® Nail to Rail System, developed by Watershed Geo, is an advanced solar racking solution designed for sites that do not require environmental closure such …
