Addressing Residual Upland Groundwater to Sediment Discharge:
Case Studies of Permeable Reactive Barrier 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 permeable reactive barriers or active caps on sediments and shorelines. These approaches reduce the “risk-of-remedy" often created by conventional sediment removal and ex situtreatment 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 trench and shoreline/sediment impacts have created a wide range of materials and designs that can be used to implement a treatment system to accomplish in situreduction of contaminant levels in groundwater, sediments, pore water and surface water with minimal impact to the target water bodies. 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.
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.