Today I am representing the Geosynthetic Materials Association, the trade group of 80 companies that manufacture, distribute and install geosynthetic materials, including liners systems. The industry employs 12,000 people throughout the United States.
Our comment to EPA is very simple. We request that EPA mandate the geosynthetic lining of coal ash storage facilities using composite lining systems. In the shortest terms, use liners, specifically composite liners.
Why? Because liners work. Concerns of safety regarding CCRs are mitigated if the landfill storage sites are lined with a composite liner system of a geomembrane and a geosynthetic clay liner. A composite liner system prevents the leachate from entering the environment. Safety concerns regarding surface impoundments are also mitigated if the impoundments are lined with a composite liner system.
The American Society of Civil Engineers does a regular “Report Card on America’s Infrastructure.”For the last three report cards, representing over a decade, solid waste has received the highest grade of any category. My industry does a good job of taking America’s waste and properly storing it to protect the environment. The materials, technology and people exist [now]—the engineers, engineering techniques and standards, the general contractors and installers who can build the proper facilities and the regulators and inspectors who assure the work is done correctly. We urge EPA to “use what exists and is working today.”
Further, our industry has continuously improved over time and EPA has been a part of that effort. Over the years, EPA has commissioned nearly 80 studies of the design and performance of lining systems. We specifically call your attention to a 2002 study titled “Assessment and Recommendations for Optimal Performance of Waste Containment Systems” (EPA 600/R-02/099). That study contains a great deal of pertinent information on how to construct containment systems. Most illustrative for today is a graph charting the leakage rate of different designs over the life cycle of nearly 200 facilities. The composite liner system of a geomembrane and a geosynthetic clay liner was demonstrated to have the lowest leakage rate over all life cycle stages, including a near zero leakage rate after the facilities are closed and final cover placed. Our materials work.
Use of composite liner systems will achieve the EPA mission to protect human health and the environment for all Americans.
A brief word on the hazardous/non-hazardous question. While coal ash does contain heavy metals, it lacks the traditional characteristics of hazardous materials, radioactivity or the presence of infectious medical waste, etc. In the opinion of our trade organization, coal ash can be properly stored using subtitle “D” regulations, a non-hazardous solid waste designation with composite liner systems.
Chart courtesy of the Geosynthetic Research Institute (GRI) at Drexel University.
Waste disposal sites in the U.S.—199 total—with a variety of designs and materials were examined. The survey population included sites at different phases of the site lifespan as indicated on the “X” axis. The site leakage (collection) rate was plotted on the “Y” axis for the three types of liner design: yellow–geomembrane alone, greenâ€“geomembrane and compacted clay, red–a geomembrane and GCL (geosynthetic clay liner) composite liner system.
The key point is the optimal performance of the composite liner system(s), including a near zero leakage rate for the closed (“After Final Cover”) site.
Data Source: Bonaparte, Daniel, and Koerner. (2002) “Assessment and Recommendations for Optimal Performance of Waste Containment Systems,” EPA/600/R-02/099. U. S. EPA, ORD, Cincinnati, OH