A Low-Impact Delivery System for In-Situ Treatment of Contaminated SedimentEPA Contract Number: EPD06029
Title: A Low-Impact Delivery System for In-Situ Treatment of Contaminated Sediment
Investigators: Menzie, Charles A
Small Business: Menzie-Cura & Associates, Inc.
EPA Contact: Manager, SBIR Program
Project Period: March 1, 2006 through August 31, 2006
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2006) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Small Business Innovation Research (SBIR) , SBIR - Cleanup of Contaminated Sediments
The focus of this Phase I project is a low-impact delivery system for in situ treatment of contaminated sediment. Unlike most conventional delivery systems that rely on injection or mechanical mixing of sediment, the proposed approach makes use of natural mixing (bioturbation) processes to work treatment materials into the biologically active zone. To accomplish this, agglomerates will be developed with the following properties: (1) dense enough to sink through the water column and provide a light nonsuffocating layer on the sediment, and (2) able to break down to release active agents over the period of weeks to months. In addition, the binders used for agglomerate must have negligible toxicity. The clear advantages over conventional systems are that it targets the biologically active zone where the benthic organisms reside, is less destructive of benthic habitats, can be used to augment Monitored Natural Recovery projects, and can be repeated, as needed, over time. The Phase I project involves: (1) the development of candidate agglomerates that can bind treatment agents such as activated carbon or valent iron; (2) testing the behavior of these in the laboratory (settling behavior, dissolution rate, formation of dusts); and (3) observing the efficacy of mixing into sediments in model benthic environments with a single test species (Nereis) and a representative community of mixed benthic invertebrates. To evaluate mixing, a fluorescent trace material will be incorporated into the agglomerate. As the agglomerate is mixed and breaks down, this trace material will be released. The distribution of the trace material within the sediment column will be examined over time (e.g., at 1- and 2-month intervals). The sediments and benthic organisms used in the model system will be representative of the Chesapeake Bay coastal waters. The material being developed, however, will have wide application to both freshwater environments (e.g., as in Lake Hartwell), as well as marine estuarine/marine systems such as Hunters Point in San Francisco Bay or the Patapsco River and Baltimore Harbor in Maryland. Application methods that will be considered at a conceptual level for Phase I include a barge-mounted fertilizer spreader and methods currently employed for thin-layer capping.