This topic includes three subtopics: (1) Cleanup of contaminated sediments; (2) Waste-to-Energy Systems; and (3) Hazardous waste monitoring. Over 40 million tons of hazardous waste are produced in the United States each year by industrial facilities such as chemical manufacturers, petroleum refineries and electroplaters, and innovative approaches to clean up sediments contaminated by these industries is needed. Agricultural wastes and wastes from animal feeding operations are also a priority under Waste-to Energy Systems and hazardous waste monitoring is the third subtopic.

CLEANUP OF CONTAMINATED SEDIMENTS

Hazardous waste contamination of near-shore and other sediments have impacted marine life, disrupted the ecological food chain and resulted in fish advisories to protect human health. Many urban rivers, harbors and bays are much cleaner now, but the sediments have concentrated many persistent bioaccumulative and toxic substances including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), creosote, pentachlorophenol and heavy metals like arsenic and mercury. Years of dumping by chemical plants, refineries, wood preservers, painting and electroplating shops, shipyards and others have contaminated the sediments.

Dredging has often been the preferred solution, but it is expensive and may have impacts on the ecosystem. Even specialized equipment resuspends some of the contaminated sediment within the water column. There are also challenges associated with disposal of the dredged sediment, particularly when the sediments are extremely contaminated. Areas of needed research include, but are not limited to:

• New technologies for beneficial use of contaminated sediments and/or dredged materials either alone or in combination with other industrial or municipal residuals or agricultural waste.
• Development of technologies that inject materials like highly reactive metal particles, iron oxide, calcium carbonate or nanoparticles and other materials for in-situ cleanup of highly contaminated sediments. Other improvements are needed to accelerate in-situ decontamination, such as using specialized catalysts or coatings or delivering the material more effectively, such as in the form of an emulsion. Specialized technologies such as in-situ elution or desorption are needed. Also, more effective ways to immobilize, detoxify or remove sediment contaminants and in-situ bioremediation techniques that use a mixture of bacteria, nutrients and sediment conditions to accelerate contaminant detoxification rates.
• Improved sediment capping materials such as reactive core mats where materials like coke-filled carpets are laid on the river bottom to detoxify or bind contaminants to prevent escape from the sediments into the water. Development of new techniques that work in the absence of oxygen deep within sediments and also utilize oxygen to detoxify upper reaches of sediments.

WASTE-TO-ENERGY SYSTEMS

EPA is interested in “waste-to-energy” technologies that combine energy efficiency with solving waste management problems. There are environmental problems associated agricultural wastes as well as with cattle feedlots, hog operations, dairies and poultry operations that confine large numbers of animals and store wastewater and manure in a contained area for extended periods of time. Among technologies of interest are gasification systems that include an enclosed thermal device and associated gas cleaning system. These systems limit oxygen concentrations in the enclosed thermal device to prevent the full oxidization of thermally disassociated gaseous compounds. Specific needs include:

• Cost effective gasification technologies and systems designed or modified to gasify animal and farm wastes, including wastes from AFOs. (For more information on AFOs, see: www.epa.gov/npdes/afo.)
• Gasification technologies and systems using AFO wastes that are part of another operation or application where technology improvements reduce or improve quality of residuals or significantly improve overall pollutant emission levels.
• Waste-to-energy systems may include high efficiency anaerobic digestion systems that produce pipeline quality methane or lower quality gas that can be used on-site to reduce farm energy requirements from outside sources.
• Biological systems that produce an enriched, easily transported feedstock for the above or other digester systems.

HAZARDOUS WASTE MONITORING

EPA’s waste management programs are seeking better sampling, analysis, and monitoring technologies to improve landfills, advance hazardous waste site cleanup and regulated waste process activities. This area includes technologies to address industrial and waste processes, accurate and cost effective identification and characterization of contaminants at waste sites, monitoring the performance of site cleanup activities and remedies both during construction and also during long-term operations, and techniques to support the closeout of cleanup activities and to support land revitalization beyond site cleanup phases. More information on these needs is available at http://clu-in.org/programs/21m2/needs.cfm. Areas with significant technology needs and gaps include:

• Technologies or systems for detecting releases that are more sensitive, less prone to human error and that are as cost effective as current leak detection methods. Development of such new technologies would demonstrate to underground storage tank (UST) owners and regulatory agencies the feasibility of improving current methods. One area of particular need is the acceptability of vapor monitoring to determine the relatively low volatile emissions characteristic of diesel fuel releases. Better leak detection techniques including improved and reliable vapor detection systems that determine leakage from low-volatile carbon compounds such as diesel.
• Improved testing method for vapor intrusion. Currently sampling methods are expensive and the analysis and validation of data is lengthy. Less expensive methods are needed that yield reproducible, defensible results in an expeditious timeframe to assist with decisions regarding the need to address subslab vapors.
• Sensor technologies for long-term monitoring of groundwater. Chemical specific (e.g., perchloroethene or trichloroethene) in-situ sensors are needed that can be queried remotely multiple times without biofouling or need for maintenance re-calibration. Sensors should meet required pollutant detection levels and be small enough, yet robust and at a reasonable cost to deploy with flux meters and piezometers to characterize change over small vertical and horizontal scales.
• Cost-effective leak detection technologies are needed for small municipal landfills. In addition, sensors are needed to monitor the integrity and effectiveness of slurry walls and liners and passive treatment (e.g., permeable reactive barrier systems).