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Case histories, papers, articles underscore role of geosynthetics
Editor’s note
The Geosynthetic Materials Association (GMA) has commented on a proposed rule from the U.S. Environmental Protection Agency (EPA). (See document below dated August 30, 2013.) The proposed rule is entitled, Hazardous and Solid Waste Management System: Identification and Listing of Special Wastes; Disposal of Coal Combustion Residuals From Electric Utilities. The purpose of the comments is for GMA to make a public statement that promotes geosynthetic materials as a best practice for coal ash storage applications as it relates to the EPA’s regulations. GMA’s comments were also discussed in congressional office visits during GMA Lobby Day on Sept. 19, 2013, in Washington, D.C.
-Ron Bygness
August 30, 2013
Mr. Steven Souders
Environmental Protection Agency
1200 Pennsylvania Ave. N.W.
Mailcode: 28221T
Washington, D.C. 20460
40 CFR Parts 257, 261, 264.265,268,271,302 et al.
Hazardous and Solid Waste Management System: Identification and Listing of Special Wastes; Disposal of Coal Combustion Residuals From Electric Utilities: Notice of Data Availability and Request for Comment, Docket ID No. EPA-HQ-RCRA-2012-0028-0001
Introduction
In response to the recent (Aug. 2, 2013) publication of the Notice of Proposed Rule Making Hazardous and Solid Waste Management System; Identification and Listing of Special Wastes; Disposal of Coal Combustion Residuals From Electric Utilities; Proposed Rule, related to the care, separation, and storage of coal combustion residuals (CCRs) the Geosynthetic Materials Association (GMA) (www.gmanow.com) offers the following additional comments and information (including attached appendices):
GMA again compliments the EPA for the statements and inclination to require geosynthetic lined facilities designed to protect the groundwater from potential contamination. GMA again recommends that the regulations put forth require the use of a composite liner system (geomembrane and geosynthetic clay liner) as this system has been demonstrated (by the EPA) to be the most effective barrier methodology, regardless of the classification of the materials (hazardous, non-hazardous or designated for beneficial re-use). This submittal supplements the previous GMA submission dated Aug. 12, and Sept. 29, 2010, and contains additional references to EPA reports and studies as well as test data generated, using EPA protocols that support the effectiveness of composite liner systems and their components, both generally and in regard to specific line of comment requested by the EPA.
Statement of EPA request(s)
In 40 CFR 257, 40 CFR 261, 40 CFR 264, 40 CFR 265, 40 CFR 268, 40 CFR 271 and 40 CFR 302, the EPA solicits comment on the feasibility of complying with the Agency’s proposed time frames for closing surface impoundments in the subtitle D option; and how the technical requirements relate to units constructed on top of closed surface impoundments or landfills (i.e., “overfills”).
Respondent comments
GMA would like to ensure that EPA is aware of all pertinent information related to the effective use of geosynthetic materials for waste containment. The Geosynthetic Institute (GSI, Drs. Robert and George Koerner, Folsom, Pa.) website contains a partial index of the U.S. EPA documents that are related to the use of geosynthetics. The complete list is linked via the webpage is here: http://www.geosynthetic-institute.org/epa.html. Clearly, geosynthetic materials have been well-examined and proven to be effective.
In the August 2, 2013 request, the EPA solicits comment on the feasibility of complying with the Agency’s proposed time frames for closing surface impoundments in the subtitle D option. GMA offers the following comments and documentation on this topic:
Historically, the EPA has had great success in its mission to protect human health and the environment by the application of the closure (also referred to as capping) components of RCRA (Resource Conservation and Recovery Act) subtitle “D” and “C’ requirements to sites where environmental containment and or remediation is needed. GMA would recommend that the functional, effective, and historically proven techniques for capping and closures that have been used in the solid waste containment industry, Superfund (CERLA) sites and liquid storage and groundwater protection be applied to coal ash storage. Specifically that a capping and closure system be designed by an appropriately licensed and qualified civil engineer, permitted by the appropriate state agency and include a geosynthetic barrier system with less than or equal permeability to that of the base liner requirements or a minimum of 10-7 centimeters per second at the maximum anticipated hydrostatic pressure, whichever is less permeable. This methodology has been successfully applied to literally hundreds of sites over the last several decades.
Some specific examples from EPA published literature are listed and linked here:
- Ripon City Landfill, Fond Du Lac County, Wis.
- Tri-County/Elgin Landfills, Elgin, Ill.
- Enterprise Avenue Landfill, Philadelphia, Pa.
Other relevant publications include:
- “Case History of a 16-Year-Old Exposed HDPE Geomembrane Cover” authored by Case, Koerner and Koerner , presented at the Global Waste Management Symposium held in Sept. 2012, Phoenix Ariz.
- “Cover systems for landfills and brownfields” authored by Heerten and Koerner
- a white paper published by the Geosynthetic Institute titled “On The Questionable Strategy of Soil-Only Landfill Covers”
This technology, engineering expertise, construction, and installation resources and materials are readily available and are currently broadly used. GMA strongly recommends that the EPA apply this technology to the existing issue of groundwater contamination from older and unlined coal ash storage facilities.
In the Aug. 2, 2013 request, the EPA also solicited comment on how the technical requirements relate to units constructed on top of closed surface impoundments or landfills (i.e., “overfills”). GMA offers the following comments and documentation on this topic:
Similarly to the capping and closure issue, the technology for construction of containment sites over existing and operational storage facilities is not new and the materials and methodologies have been in use for decades and have proven effective, reliable, and well-understood. In the solid waste industry, this methodology also is termed vertical expansion or “piggybacking.” This addresses the situation that EPA is requesting comment on, that is the construction of a (presumably lined) facility over an existing coal ash storage site. Again, several hundred sites of this type have been constructed, some, as will be referenced, are very large, complex storage sites. The geosynthetic materials have long existed to properly design, support, and construct the stable and long-lasting geotechnical structures that hold these materials. In fact, coal ash in many ways is a simpler and less variable problem that engaging in this type of construction with solid waste materials; the relative consistency of coal ash and its more homogeneous and stable properties (relative to solid waste with variable liquid contents) will allow for more accurate predictions and improved reliability in the construction of coal ash storage sites.
Many examples from EPA published literature are available. A specific EPA-published study addressing both static and seismically active areas is “Seismic Design Guidance for Municipal Solid Waste Landfill Facilities” authored by Richardson, Kavazanjian and Matasovic: (Report No. EPA 600/R-95/051) linked here: http://smithgardnerinc.com/docs/1995-Seismic_Design_Guidance_for_Municipal_Solid_Waste_Landfill_Facilities.pdf.
In fact, as early as 1993, geosynthetic reinforced slopes contacting and containing coal ash were being constructed at the E.B. Brown Power Generation Facility in Mercer County, Ky. The successful performance of this methodology was documented in the paper by D. W. Armour Jr. and C.M. Avery, “Design, Construction and Performance of a Test Embankment on Hydraulically Placed Ash” (Proceedings, Geosynthetics 1993, Vancouver, B.C., Canada, March 1993, pg. 1243 – 1258) links here: http://www.gbv.de/dms/tib-ub-hannover/183688635.pdf and here: http://infohouse.p2ric.org/ref/29/28906.pdf.
Many very large-scale solid waste expansions and reinforcements of existing sites have been constructed and reported on, two examples are published by Geosynthetics magazine: “ Massive soil reinforcement at Cherry Island extends landfill’s use for decades” linked here: http://geosyntheticsmagazine.com/articles/1012_f1_soil_reinforcement.html and “Bluffside stabilization in Kansas City linked here: http://geosyntheticsmagazine.com/articles/0812_f4_wall_apartment.html. The paper: A Project of Many Firsts: The South Hadley Landfill Cell 2D Vertical Expansion (link here: http://keystoneswana.org/DocumentCenter/View/88 ) describes an existing site that could only be expanded with the use of geosynthetics.
Most recently some articles have turned to the specific examination of coal ash sites: “Use of Bottom Ash in the Reinforced Zone of a Mechanically Stabilized Earth Wall for the Vertical Expansion of a Sluiced CCR Pond at the Trimble County Generating Station” by Schmitt and Cole (linked here: http://www.flyash.info/2013/125-Schmitt-2013.pdf ) speaks specifically and directly to the EPA’s request and affirms the value and effectiveness of geosynthetic materials in providing a solution to this problem.
Further, an additional publication within Geosynthetics magazine, “Sustainability Contribution By MSE Berms At Landfills” by Brown and Liew (linked here: http://geosyntheticsmagazine.com/articles/0812_f2_berms_landfills.html ) discusses the benefits of MSE berms relative to sustainability, and in terms of carbon footprint, of an MSE berm vs. a traditionally constructed, unreinforced one. Finally, it is noteworthy that the state of North Carolina has established a regulation addressing the construction of additional storage on existing sites. This regulation (linked here: http://law.justia.com/codes/north-carolina/2012/chapter-130a/article-9/section-130a-295.4 ) in addition to the considerations for structural stability, prescribes a special liner for this application. This requires that a “leak detection layer” be included in the bottom liner design for such vertical expansions. An action leakage rate is established in the leak detection layer providing early warning of possible infusion of liquid into the CCR mass.
Conclusion
The benefits and successes of utilizing geosynthetic barriers and reinforcements in containment systems has been well documented by the technical materials supplied by GMA previously and further referenced here. Geosynthetics have been tested and successfully evaluated in great detail over a long period of use in a very wide range of applications by EPA. Specific to this EPA request, geosynthetics are essential elements of successful capping and closure installations and geosynthetic reinforcements allow of construction over existing sites with reliable safety and cost-effectiveness.
GMA recommends that the U.S. EPA CCR Disposal Proposed Rule utilize the subtitle D Regulation option, that capping systems be required to have equal to or lower permeability than the regulatory requirement for base liner systems and that available geosynthetic reinforcement materials which have demonstrated success at construction on top of closed surface impoundments or landfills (i.e., “overfills”) be utilized in that manner.
GMA thanks the EPA for the consideration provided. GMA, the respective member companies, and their staffs are more than willing to respond to any additional EPA inquiry on this or other related topics.
Sincerely,
Andrew M. Aho
Director, Technical Markets
Industrial Fabrics Association International
1801 County Road B. West
Roseville, MN 55113-4061
Boyd J. Ramsey
Chairman, Executive Council
Geosynthetic Materials Association
GSE Lining Technologies Inc.
19103 Gundle Road
Houston, TX 77073