In-Situ Remediation of Residual Upland and Sediment Contamination and Groundwater to Surface Discharge: Case Studies of Full-Scale Treatment Systems
John Collins, General Manager and COO, AquaBlok, Ltd.
Co-Author: John H. Hull, P.E., AquaBlok, Ltd.
Residual upland contamination can impact nearby surface water and sediments at petroleum and MGP sites. In some cases, groundwater can be impacted by soil residuals, which can subsequently contaminate both surface water and sediments. These impacts can be minimized using combinations of low-permeability material with adsorptive or reactive treatment materials in active caps on sediments and shorelines. These approaches reduce the “risk-of-remedy" often created by conventional sediment removal and ex situ treatment and avoid the unsustainable practice of moving the problem from one media to another (i.e. from sediment to upland landfill). Advancements in materials and placement systems for shoreline and sediment impacts have created a wide range of materials and designs that can be used to implement an “active cap” treatment system to accomplish in situ reduction of contaminant levels in sediments, pore water and surface water with minimal impact to the target water bodies. Treatment materials of various sizes and specific gravity can be placed uniformly in combination with bulk material such as sand and gravel. Laboratory evaluations using various composite aggregate formulations for adsorption of organic contaminants and selected metals have been performed using both batch tests and flow-through columns to illustrate active capping applications. Data collected on removal efficiencies and modeling will be presented to illustrate the impact of the addition of reactive materials to the composite aggregate to treat contaminants and to discuss their relative influence. Treatment materials, such as organoclays and activated carbon, have provided appreciable reduction of contaminants to both petroleum and MGP sites at full-scale and can be incorporated into composite particles with targeted cap permeabilities. This paper will present data from lab testing and profiles of full-scale installations of reactive caps alone, and in combination with a low-permeability capping material.
John Collins is the General Manager and COO of AquaBlok, Ltd. Mr. Collins is responsible for all day-to-day activities of the company, including technology development, manufacturing, and marketing. AquaBlok developed, patented and manufactures a wide range of materials using their unique technology in not only the environmental remediation markets, but also in phosphorous reduction, annular sealants, pond/canal liners, and other geotechnical segments. Mr. Collins has over 25 years’ experience in a variety of engineering and environmental related businesses managing research, product development, technology licensing, capital goods manufacturing, and acquisitions. He has been with AquaBlok for twelve years and has guided the development of several new products and managed multiple major remediation projects.