Utilities face many challenges as they move forward developing programs to deal with disposal or recycling of coal combustion residuals (CCR). The U.S. Environmental Protection Agency (EPA) recently proposed changes to the 2015-enacted federal coal ash rule and issued a proposed Federal permitting program rule for CCR.
SCS Engineers closely follows developments relating to coal ash disposal. The company works with landfill operators, utilities, and others who deal with CCR to meet the challenges of proper waste management as federal, state, and local regulations evolve.
In addition to evaluating the impact of proposed rule changes and permitting programs, many utilities are currently working to address groundwater impacts from CCR units monitored under the current Federal CCR rules (40 CFR 257 Subpart D—Standards for the Disposal of Coal Combustion Residuals in Landfills and Surface Impoundments). Based on timing in the CCR rule, utilities have recently completed an Assessment of Corrective Measures (ACM) for groundwater impacts and are working on selecting a remedy for the groundwater impacts identified.
The remedies for CCR units not already closed include some form of source control, along with strategies to limit impacts to groundwater. The most prevalent remedies today include closure-in-place, or cap-in-place, of coal ash storage sites, or closure-by-removal, in which CCR is dewatered and excavated, then transported to a lined landfill.
“The answer to this question is wide and varied,” said Eric Nelson, a vice president with SCS. Nelson is one of the company’s national experts for electric utilities, and an experienced engineer and hydrogeologist. “In part, it depends on the situation” Nelson noted that remedies for disposal of waste such as CCR from power plants could differ from the disposal of municipal solid waste (MSW) or everyday trash.
“Is the landfill or impoundment already closed or capped, is it active or inactive, what type of CCR or waste (is being disposed of)?” Nelson said. “Then there’s the physical setting, the geology, the receptors or lack of receptors. My opinion is that the industry is in a tough spot because the remedy selection process is strongly influenced by opinion and widely varied regulatory climates.”
“For instance, selecting a remedy, which in many cases will include closing a surface impoundment, that leaves CCR in place feels risky to some due to what is happening in places like the Carolinas and Virginia,” Nelson said. “Anything short of exhumation and re-disposal seems to be cast as insufficient by some when closure in place is a tested and proven response in other arenas [such as MSW]. A one-size-fits-all solution isn’t appropriate.”
Some utilities have moved forward with complete excavation, removing ash, and re-disposing it in a lined landfill. Some of these projects have likely been influenced by local efforts to dictate the remedy selection process through negotiation or legislation. The fact that some utilities have selected closure-by-removal does not mean this remedy is suitable in all situations.
Sherren Clark, vice president and Solid Waste Services Division leader for the Upper Midwest Region of SCS, said: “In terms of remedy selection, one key difference between MSW and CCR sites has been that for CCR sites, total CCR removal is an option that has been put on the table, and is being implemented at some sites, both small and large. For MSW, total waste removal has very rarely been the chosen approach and has typically been thought of as infeasible unless there were other financial drivers supporting that choice. The typical approaches for MSW sites have focused on source control options, such as an improved cap or enhanced landfill gas collection systems.”
Nelson said that engineers working on plans for CCR disposal could look at what’s been done at MSW sites.
“We might discuss the various approaches to corrective action that are described in some early guidance for MSW work,” Nelson said, pointing to EPA Technical Manual EPA530-R-93-017, which deals with solid waste disposal facility criteria and addresses active remediation, plume containment, and source control. “I believe there are significant guidance and experience we can draw from the MSW arena on the different remedies and how to evaluate them.”
Nelson said that “potential remedies must be evaluated according to the requirements in 40 CFR 257.96 and 257.97,” which are EPA rules outlined in the Electronic Code of Federal Regulations (e-CFR). Part 257 details Criteria for Classification of Solid Waste Disposal Facilities and Practices, including Subpart D-Standards for the Disposal of Coal Combustion Residuals in Landfills and Surface Impoundments, including groundwater monitoring and corrective action. Section 257.96 deals with ACMs. Nelson notes an important distinction with this approach: “One important note is that cost cannot be considered as it is in the similar rules for MSW.”
Jennifer Robb, vice president and project director with SCS’s Solid Waste Services Division in Reston, Virginia, said programs for the disposal of MSW “are pretty much identical to the process a [CCR] site has to go through. The only difference is the constituents they sample the groundwater for. The CCR sites, they’re going to have an issue with metals. The big problem with that is, a lot of the metals are naturally occurring.”
Robb noted that’s where the alternate source demonstration (ASD) comes in, to determine the source of contaminants, and whether a CCR pond or other ash storage facility is responsible for causing levels of contaminants to excess groundwater protection standards.
Evolving Regulatory Landscape
The Environmental Protection Agency (EPA) is proposing a streamlined, efficient federal permitting program for the disposal of coal combustion residuals (CCR) in surface impoundments and landfills, which includes electronic permitting. The new rules are designed to offer utilities more flexibility and provide regulatory clarity.
(1) In August 2019, EPA proposed amendments to CCR regulations that encourage appropriate beneficial re-use and clarity on managing coal ash piles. The proposal would also enhance transparency by making facility information more readily available to the public.
(2) A November 4, 2019, proposal establishes August 2020 as the date for utilities to stop receipt of waste in affected impoundments. It gives utilities the ability to demonstrate the need to develop new, environmentally protective waste disposal technology subject to EPA approval.
(3) On December 19, 2019, EPA proposed a federal permitting program for coal ash disposal units. The proposal includes requirements for federal CCR permit applications, content, and modification, as well as procedural requirements. EPA would implement the permit program at CCR units in states that have not submitted their own CCR permit program for approval. EPA already accepted and approved state permitting programs in Oklahoma and Georgia and is working with others to develop their programs. On December 16, 2019, the EPA Administrator signed a Federal Register notice approving Georgia’s state permit program for the management of CCR.
The November proposal addresses the deadline to stop accepting waste for unlined surface impoundments managing coal ash. It includes a new date of August 31, 2020, for facilities to stop placing waste into these units and either retrofit them or begin closure. The proposal would allow certain facilities additional time to develop an alternate capacity to manage their waste streams before initiating closure of surface impoundments. It would also re-classify clay-lined surface impoundments from “lined” to “unlined,” which means that clay-lined impoundments would have to be retrofitted or closed. Under the proposal, all unlined units would have to be retrofitted or close, not just those that detect groundwater contamination above regulatory levels.
The 60-day comment period on the November proposal closes January 31, 2020. The EPA will conduct a virtual public hearing about the proposed rule on January 7, 2020, at 9 a.m. Eastern Time. Register for the meeting to learn more. A 60-day comment period for the proposed federal permitting program will begin once the rule is published in the Federal Register.
This blog series highlighting the experience and expertise of SCS Engineers staff will continue with a look at examples of remedies for coal ash disposal and storage. If you have questions, contact the authors by selecting one of their names, or email us at firstname.lastname@example.org.
Solar Ready CCR Site Closures Help Energy Companies Move Toward a Sustainable Future
Electricity is the one big energy source that can be free of carbon emissions. You can make it from the sun. You can make it from the wind. Tap the heat of the Earth, hydropower. While all utilities are moving in a sustainable, environmentally friendly direction, Aliant Energy stands out for making progress and keeping rates reasonable for consumers.
At the recent USWAG Workshop on Decommissioning, Repurposing & Expansion of Utility Assets held October 2019, Eric Nelson presented on the opportunities for solar generation at closed CCR sites and provided an overview of civil and geotechnical considerations when redeveloping closed sites as solar generating assets. His presentation demonstrated these considerations through the use of a case study.
SCS Engineers has assisted Alliant Energy with the design and/or construction of multiple coal combustion residual (CCR) surface impoundment closures. Two of the completed closures are the former Rock River Generating Station in Beloit, Wisconsin, and the M.L. Kapp Generating Station in Clinton, Iowa.
Both sites were closed by incorporating Alliant Energy’s vision to create “solar ready” sites. The Rock River site is now home to just over 2 megawatts (MW) of solar photovoltaic (PV) generating capacity, which was developed on the footprint of the now-closed on-site landfill and ash ponds. Although no solar assets have been developed at the site, the M.L. Kapp ash pond closure represents another opportunity for Alliant Energy to repurpose a closed ash pond for clean power.
Two additional closure designs are in process that incorporates similar elements, making them available for future solar generating asset development.
Eric J. Nelson, PE, is a Vice President of SCS Engineers and one of our National Experts for Electric Utilities. He is an experienced engineer and hydrogeologist.
When the Federal Coal Combustion Residual (CCR) rule went into effect in 2015, it was a new regulatory layer on top of a widely varying landscape of state regulations affecting CCR management in impoundments and landfills. Some states already had significant regulations on the books for CCR impoundments and/or landfills, while others did not.
Where state regulations existed, they varied widely from state to state. While a few states have moved toward closing the gap between state and Federal CCR requirements, many utilities continue to face confusing and conflicting requirements coming from different regulatory programs as they move ahead with managing their CCR facilities.
In her paper entitled State vs Federal CCR Rule Regulations: Comparisons and Impacts, Nicole Kron shares state-versus-federal regulatory challenges utilities have encountered during landfill design and management, impoundment closure, and groundwater monitoring and reporting since the implementation of the Federal CCR rule. For example, some sites have completely distinct groundwater monitoring programs under state-versus-federal rules, with different well locations, well depths, and monitoring parameters for the same facility. She highlights unique approaches to bridging regulatory gaps and resolving regulatory conflicts between state and Federal CCR requirements. Ms. Kron also provides insights gained on the long-term potential for regulatory resolution of these issues based on discussions with state regulators in multiple states.
About the Author: Nicole Kron has nearly a decade of experience in the environmental consulting field. Her experiences focus on groundwater quality analysis of sites contaminated with coal gasification byproducts, coal combustion byproducts, chlorinated solvents, petroleum products, metals, and PCBs. Her experience includes managing team task coordination, groundwater modeling, and statistical analysis of CCP/CCR sites. She is experienced in planning and performing soil and groundwater contamination investigations, air monitoring, well design and installation, and soil and groundwater sampling.
The World of Coal Ash (WOCA) conference is an international conference organized by the American Coal Ash Association (ACAA) and the University of Kentucky Center for Applied Energy Research (CAER). The 2019 conference will be held May 13-16, 2019, in St. Louis Missouri. This 8th joint biennial meeting will focus on the science, applications and sustainability of worldwide coal combustion products (CCPs) as well as gasification products.
SCS Engineers is a Platinum sponsor of this year’s conference, and numerous SCS professionals plan to present or attend, including our Senior Vice President of Environmental Services, Mike McLaughlin. Our presenters will be:
Check back for more details, which will be posted as the agenda is finalized.
Even the simplest impoundment closures come with design challenges. It is a challenge to navigate project constraints, whether technical, regulatory, or financial, to design and implement an effective closure strategy. Cost often helps to determine the “balance” between project constraints when the future end use of a closed CCR surface impoundment or the property it occupies is undefined. When a post-closure end use is defined, finding balance among project constraints to best serve that future use provides rewarding challenges.
SCS Engineers has navigated this balancing act on impoundment closure projects during facility decommissioning. Through a presentation of case studies, you will learn how this team has approached ash pond closure planning and execution where the future use of the impoundment site ranged from undefined to the home of a new solar photovoltaic installation. Examples also include potential future industrial use or property sale.
Case studies will highlight how geotechnical, hydrological, regulatory, or simple physical constraints have influenced the design and implementation of CCR surface impoundment closures.
A Midwest power plant that was constructed as a zero discharge facility in 2012 was experiencing water management issues due to excessive absorber recycle water with concentrated chlorides and leachate generation from the CCR landfill at the facility. The facility started exploring wastewater management options in 2013 that consisted of evaluating the feasibility of a deep injection well as a fluid disposal option and the results indicated that this option was a technically feasible alternative.
From 2014-2015 the plant continued to experience water balance and chlorides management challenges and conducted a plant review and water balance study to see if the chloride concentration and leachate generation issue could be resolved through process changes within the plant. The resulting water balance study concluded that while minor changes and optimizations could occur, it would not resolve the underlying water quality or water balance challenges at the facility. Other water disposal and management options were also explored by the plant in that included RO, evaporators and the deep well as retained alternatives.
In 2016, the deep injection well was selected as the preferred water management alternative and permitting was initiated. The goal was to get the deep well permitting started while the plant refined plant process modifications and additional water quality data on the feed water(s) is collected.
Water quality data from the site has indicated that iron, carbonate and sulfate are the dominant water quality parameters that drive scaling within the current system and will need to be addressed prior to injection so the well does no scale and clog.
The deep well was completed in 2018 and the final surface treatment system is currently under design. The facility anticipates full-scale operation of the system in early 2020.
When the Federal CCR rule went into effect in 2015, it was a new regulatory layer on top of a widely varying landscape of state regulations affecting CCR management in impoundments and landfills. Some states already had significant regulations on the books for CCR impoundments and/or landfills, while others did not. Where state regulations existed, they varied widely from state to state. While a few states have moved toward closing the gap between state and federal CCR requirements, many utilities continue to face confusing and conflicting requirements coming from different regulatory programs as they move ahead with managing their CCR facilities.
Through case studies, SCS Engineers will share state-versus-federal regulatory challenges utilities have encountered in different regions of the country during landfill design and management, impoundment closure, and groundwater monitoring and reporting since the implementation of the Federal CCR Rule. For example, some sites have completely distinct groundwater monitoring programs under state versus federal rules, with different well locations, well depths, and monitoring parameters for the same facility. We will highlight unique approaches to bridging regulatory gaps and resolving regulatory conflicts between state and Federal CCR requirements.
SCS will also share insights gained on the long-term potential for regulatory resolution of these issues based on discussions with state regulators in multiple states.
Learn how to minimize leachate and contact water management at coal combustion residual (CCR) landfills using good design, physical controls, and operational practices. Through our presentation of case studies, you will learn how to assess leachate and contact water management issues and implement techniques to minimize leachate and contact water management at your landfill.
Leachate management and contact water management at CCR landfills can be expensive, cause operational headaches, and divert valuable resources from other critical plant needs. Our presentation will provide you with useful tools to ensure your landfill is designed and operated to effectively reduce leachate and contact water and alleviate operator stress. We will present case studies that highlight how design features, physical controls, and operational practices have effectively decreased leachate and contact water management at CCR landfills.
The Utility Solid Waste Activities Group (USWAG) will host a CCR Workshop, March 20-21, 2019 at the Hilton Crystal City at National Airport in Crystal City, Virginia, near Washington, DC. Meet SCS professionals Nicole Kron, Eric Nelson, and Monte Markley, all of whom will be presenting at this prestigious event. SCS Senior Vice President of our Environmental Services Division, Mike McLaughlin, will also participate in the workshop.
Visit SCS Engineers at Booth 483 and meet our professionals, including Mike McLaughlin, Phil Gearing, Eric Nelson, Jeff Pierce, and Sarah Hoke at the 22nd Annual EUEC 2019: Energy, Utility & Environment Conference, February 25 – 27, 2019, at the San Diego Convention Center. SCS presentations will include:
Phil Gearing will speak about
“How to Minimize CCR Landfill Leachate and Contact Water Management”
Eric Nelson will present on
“Finding Balance: How Future Use Guides Ash Pond Closure Strategies”
Jeff Pierce will speak about
“Conversion of Biogas Renewable to Power to RNG – a Value Proposition”
The EUEC will feature exhibits, networking, and 10 speaking tracks:
This is the largest professional educational training & networking event of its kind in the United States. Mark your calendars!