The staff at SCS Engineers (SCS) has talked at length about how changing the parameters of a coal ash remediation project impacts the eventual outcome of that project. That involves not only the factors present at a particular site but also the regulatory environment in which that site operates, certainly as rules evolve regarding the disposal of coal combustion residuals (CCRs).
Two primary means of coal ash remediation are closure-in-place, or cap-in-place, of an existing coal ash storage site, and closure-by-removal. Closure-in-place involves dewatering the storage site, or impoundment, in effect converting from wet storage to dry storage of ash. A cover system is then used to prevent more water from entering the site.
Closure-by-removal involves dewatering of the coal ash, and then excavating it, and transporting it to a lined landfill or a recycling center.
“There are lots of technical reasons and site-specific factors that can influence a project’s outcome,” said Eric Nelson, vice president of SCS and an experienced engineer and hydrogeologist. “These might include the type and volume of CCR, the geologic setting [e.g., groundwater separation], presence and proximity of receptors [e.g., drinking water supply], and physical setting [e.g., constraints such as access, available space onsite for re-disposal, proximity/availability of offsite re-disposal airspace, etc.].”
Sherren Clark, an SCS team member with experience in civil engineering and environmental science, said “risk evaluation is a key component of remedy selection. A CCR unit undergoing an assessment of corrective measures [ACM] could be a 100-acre ash impoundment containing 30 feet of fly ash, but it also could be a 2-acre bottom ash pond. It could have numerous groundwater constituents exceeding drinking water standards by a significant margin, or it could have a single parameter slightly above the limit at a single well. And there could be water supply wells nearby in the same aquifer, or none for miles around. All of these factors play into the selection of a remedy that addresses the existing risks, without creating other negative impacts such as site disturbance, dust, or truck traffic.”
Tom Karwoski, a hydrogeologist and project manager for SCS who has designed and managed investigations and remediations at landfills as well as industrial, Superfund, and other waste storage sites, noted the challenges inherent to individual sites and stressed careful planning is needed to achieve the desired result. At some sites, “given the size and the nature of the impoundments, transport of CCR off-site may not be the best option.” When moving from the ACM to the remedy [selection], it’s extremely important to have multiple meetings with the client to set the schedule. Based on the way the [CCR] rule is written, things have to progress logically. There’s time available for careful planning. The last thing we want to do is start making assumptions without input from the client and other interested parties. Regulatory compliance and concern for the surrounding community and the environment are important to us and our clients.
“If the nature of the site in its current condition allows it, capping of the site will reduce surface water moving through the waste and significantly cut down on the risk of groundwater contamination,” Karwoski said. “At sites where you have CCRs that may be distributed across a site, to consolidate that onsite and then the cap will address CCRs impacting groundwater.”
Jennifer Robb, vice president and project director with SCS’s Solid Waste Services Division, and the company’s Groundwater Technical Advisor for the Mid-Atlantic region said her group has “done corrective measures for cobalt, arsenic, and thallium,” all contaminants found in coal ash. “There are some in situ bio-remediation that can be done, where basically you’re trying to alter the chemistry to immobilize the metal.” Jennifer noted that there are also more physical remedies where contaminated groundwater is extracted from the subsurface by pumping or the groundwater plume is contained or treated in-situ with the construction of “cut off trenches.”
Karwoski said, “we have no preconceived notions about what is best for all sites, but if you consolidate [waste] onsite and then cap, it will certainly take care of a lot of situations where you have CCRs impacting downgradient groundwater.” This approach may not be appropriate in every situation, but, if arrived at after thoughtfully navigating the remedy selection process defined in the current Federal CCR rules (40 CFR 257 Subpart D—Standards for the Disposal of Coal Combustion Residuals in Landfills and Surface Impoundments), should result in an approach that is effective based on the site-specific factors present.
Read last month’s blog “Many Factors Influence Remedies for CCR Control and Disposal.”
California leads the way in the United States with a GHG MRP and C&T program that continues to grow and link with other jurisdictions. The California Air Resources Board (CARB) Market Readiness Proposal initially started with basic facility reporting and has grown and adopted to include multiple non-facility specific sectors of the economy, as dictated by the growing initiatives and programs that CARB joins or creates. However, as the program applicability may change, the basics tenants of MRP stay the same with reporting and verification at the center of the program.
By having CARB’s C&T Program as a separate program, entities have to navigate if they have a compliance obligation and how they will meet that obligation in addition to complying with reporting requirements. Entities can reduce their emissions by switching to biomass-derived fuels or meeting their compliance obligation by using CARB-provided allowances or purchasing allowances and/or compliance offset credits.
As CARB’s programs grow, it will likely trigger similar growth in the western North American GHG programs and regional agreements. As discussed, Québec’s C&T system, which is linked with CARB’s program, has been growing and is being used to meet the Canadian federal GHG rules that are being put in place. Ontario’s program was annulled but shows that the discussion on how best to reduce GHG emission is a topic that continues to thrive, and we may see new programs developing even though some may hit some setbacks. The PCC shows that even if a Market Readiness Proposal and C&T Program is not the particular method chosen by a region to reduce emissions, many regions still see reducing GHG emissions as the future to create jobs, develop the economy, develop new infrastructure and maintain growth while protecting the environment.
About the Authors:
Cassandra Drotman Farrant is experienced in environmental consulting, specializing in environmental assessment and greenhouse gas (GHG) verification. She has participated in GHG verification projects throughout the U.S.
Raymond H. Huff is SCS Engineers’ National Expert on Greenhouse Gas. He specializes in landfill regulatory compliance; air quality/compliance issues, including GHG emissions quantification; and site assessment, remediation, and post-closure care.
Haley DeLong is experienced in greenhouse gas (GHG) emissions, sustainable energy, and climate dynamics. She specializes in air quality consulting and has been involved in numerous projects related to air permitting and compliance with solid waste regulations, including preparing Title V and Non-Title V permit-to-construct/operate permit applications.
Do Tracer Environmental professionals ever slow down? The SCS Tracer professionals at SCS Engineers were busy publishing new articles last month in addition to Operator Training. We’ve compiled several of them along with the most popular in our SCS library for your convenience. Select a title and start reading. Enjoy!
How to Properly Complete an IIAR 6 System Safety Inspection Checklist Form? When filling out the ANSI/IIAR 6-2019 Ammonia Refrigeration Safety Inspection Checklists, located in appendix B, some of the information required may not always be readily accessible. This comprehensive article takes readers step-by-step through the process.
Epic Fails, Part Deux Failures that come together, form a picture. The author discusses how we can begin to learn from these Epic Fails and start to take steps to prevent them in our plants.
Ammonia Pipe and Equipment Labeling – Part I Recognized and Generally Accepted Good Engineering Practices (RAGEGEP), an overview of many of the standards and guidelines that are relevant to the ammonia refrigeration system labeling, and guidance on how to apply them.
Ammonia Pipe and Equipment Labeling – Part II Options facilities have when choosing their RAGAGEP for pipe and equipment labeling.
It’s All in Your Past, RETA Breeze Investing in the knowledge and development of your personnel is the first step towards making your management system world-class in the safe operation and maintenance of your ammonia refrigeration system.
Employee Training Under PSM/RMP FAQs about designing a training program that is part of your facility’s PSM and RMP programs and provides a defensible position during inspections while ensuring that your facility operators and maintainers perform their jobs safely.
Mechanical Integrity, Documentation Discrepancies Checks, and verification prevent big problems.
Managing Organizational Change: How it Impacts Your Ammonia Refrigeration System During periods of organizational change, we must keep in mind the potential impacts on our facility’s PSM/RMP or ARM programs, and on the operation of the ammonia refrigeration system itself.
PSM/RMP Compliance Audits: Who Should Perform Them? What to look for in an auditor for hire? For starters, more than a consultant familiar with PSM/RMP regulations.
Management of Change: Have We Captured All of the Impacts of a Change? It is vital to ask as many questions as possible regarding equipment changes under consideration. With more information, you may find that the proposed changes could impact safety.
SCS Engineers Summer Internships
Openings and applications here
SCS provides valuable technical and engineering business experience as you work alongside our professional staff on a diverse range of solid waste and environmental projects. Opportunities can jump-start your career path as SCS interns become part of the solutions we deliver to our clients.
Opportunities in 2020 are available nationwide.
Interns typically work 40 hours per week. Paid internships start in May or June, and end in August or September; your exact start and end dates are arranged to accommodate your school schedule.
Learn more about the SCS Engineers program here.
The U.S. Environmental Protection Agency (EPA) has identified 1, 2, 3 – Trichloropropane (TCP), which does not occur naturally in the environment, as an emerging chemical of concern that can threaten drinking water supplies. It states that TCP is a persistent pollutant in groundwater and has classified it as “likely to be carcinogenic to humans.” California State Water Board member Steven Moore called TCP an “insidious chemical” because it persists in the environment, sinks in water and is harmful in even tiny doses. Currently, there is no federal maximum contamination level (MCL) for TCP; however, there is a federal non-enforceable health-based screening level of 0.00075 ug/L.
Since 2012, TCP has been on the emerging Contaminant Candidate List (CCL), which is a watch list of unregulated contaminants that are known to, or anticipated to, occur in public water systems and may require regulation under the Safe Drinking Water Act (SDWA). The EPA has required, under the Unregulated Contaminant Monitoring Rule (UCMR), that large water systems test for TCP every five years with a minimum reporting level of 0.03 μg/L. This rule allows for the EPA to monitor contaminants suspected to be in drinking water that are unregulated under the SDWA. As a result of the testing, TCP has been identified across the US in drinking water sources. Currently, there is no federal maximum contamination level (MCL) for TCP; there is a federal non-enforceable health-based screening level of 0.00075 ug/L.
The author continues the paper with an examination of what TCP is and how it impacts our environment and our health. She then discusses regulatory policies and how California’s mandatory TCP standard could be a blueprint for other state water agencies currently investigating how to enhance their own drinking water protections from emerging contaminants.
Lyn covers some of the legal aspects, risks to businesses, detection, and treatment options to conclude her white paper. She also provides plenty of resources to start the journey toward sustainable treatment solutions that communities can afford.
About the Author: Lynleigh Love is a Senior Project Geologist with SCS Engineers. She has been a professional geologist for more than 22 years with extensive technical expertise in environmental assessment, remediation, and regulatory compliance. Her experience includes groundwater/soil vapor monitoring, excavation work plans, and remedial action plans.
Lessons learned from previously constructed gas collection and control systems teach solid waste professionals valuable lessons about designing for long-term survivability and reducing the maintenance cost of gas system components. The location impacts operating and maintenance costs for various components of gas collection and control systems such as condensate force main, condensate sumps, force main for well liquids, air lines to pumps in gas wells, and gas headers long into the future. As often as possible, design the gas header in the landfill perimeter berm along with the condensate sumps. Landfill perimeter berms constructed in an engineered manner with well- compacted soils and a well-defined geometry provide a long-term cost-effective alternative to earlier designs outside the berm.
For many years, gas headers were designed and constructed outside of the landfill perimeter berm, on the landfill surface. Of course, landfill surface changes as waste elevation increases over time, resulting in many gas headers that now may be 30 feet or more below the current waste surface. Deeply buried gas headers are unreliable at best, and the operator loses access to them as soon as 20 feet of waste covers the header.
Collapsed gas headers buried deep in waste are an expensive challenge when operating a large number of gas wells connected to the gas header, and could cause serious compliance issues. Upon discovery of a collapsed buried gas header, installing a new header is a lengthy process with significant costs, not to mention the hurdles the operator will have to jump addressing noncompliance with their state agency.
The benefits of placing gas headers in the landfill perimeter are:
Since the condensate force main follows the gas header in the perimeter berm to flow to a tank or discharge point, there are additional maintenance benefits.
By continuing to design gas header construction on landfill slopes, all of the components end up on the landfill slope as well. You can imagine what type of complications the landfill operator will face since all of these components are in areas vulnerable to erosion, settlement, future filling or future construction. Additionally, any maintenance requiring digging and re-piping necessitates placing equipment on the landfill slope and disturbing the landfill slope surface for an extended period.
For more information about these benefits and more, please refer to the MSW Magazine article series Considerations for the Piping Network, the author, or contact SCS Engineers at .
About the Author: Ali Khatami, Ph.D., PE, LEP, CGC, is a Project Director and a Vice President of SCS Engineers. He is also our National Expert for Landfill Design and Construction Quality Assurance. He has nearly 40 years of research and professional experience in mechanical, structural, and civil engineering.
Learn more at Landfill Engineering
SCS Engineers Summer Internships
Openings and applications here
SCS provides valuable technical and engineering business experience as you work alongside our professional staff on a diverse range of solid waste and environmental projects. Opportunities can jump-start your career path as SCS interns become part of the solutions we deliver to our clients.
Opportunities in 2020 are available nationwide.
Interns typically work 40 hours per week. Paid internships start in May or June, and end in August or September; your exact start and end dates are arranged to accommodate your school schedule.
Learn more about the SCS Engineers program here.
PFAS are also key components in aqueous film-forming foam (AFFF), which is used to fight petroleum-based fires at aviation and manufacturing facilities. For decades, AFFF containing PFAS has been used extensively at airports throughout the world to protect the safety of passengers, crew, and others. The FAA requires that commercial airports train with, calibrate equipment with, and use the best performing AFFF fire suppression systems. AFFF is required to be used at airports and must be certified to meet strict performance specifications, including those mandated by the U.S. Department of Defense Military Specifications.
Lynleigh Love and Chris Crosby of SCS Engineers discuss the risks and issues with PFAS-based firefighting foam used at airports. The authors cover the regulatory climate, contamination investigations, operational and environmental management and litigation, along with alternatives to using traditional AFFF. There are some possible alternatives that can mitigate health risks in your community.
Read this article to help inform your mitigation plan and strategies to minimize risk.
Article published in the January 2020 edition of Waste Advantage Magazine.
At the Federal level, GHG emission reporting has become part of the standard regulatory requirements; however, on the west coast, GHG programs continue to develop and evolve from reporting to reduction programs beyond federal requirements. Solid waste facilities can be impacted by all of these reporting mechanisms directly as a landfill located in the state in question, opting in for C&T as part of the LCFS in California, or in limbo, as the courts work out the legality of Washington’s Clean Air Act. More stringent federal GHG requirements are unlikely with the current administration, however, that could change with the 2020 election. In general, GHG rules and legislation keep developing and updating to account for and reduce GHG emissions.
Read, share, or download the full article here.
Cassandra Drotman Farrant is Project Manager with SCS Engineers. She has nine years of experience in environmental consulting, specializing in environmental assessment and greenhouse gas (GHG) verification. Cassandra has participated in many GHG verification projects throughout the U.S. and has completed approximately 70 Phase I Environmental Assessments (ESAs) in California, Oregon, and Washington. Phase I projects included research and review of geologic and hydrogeologic conditions at project sites and in the surrounding areas and evaluating the potential for soil and groundwater contamination from on and offsite sources. Cassandra has completed emissions estimates and inventories and has prepared numerous permit-to-construct/operate permit applications. She prepares compliance reports, which includes reviewing and maintaining records and regulatory deadlines.
SCS Engineers provides engineering, consulting, operations and monitoring services to report and reduce greenhouse gas emissions. Select a service category to learn more.
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 .
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